The importance of tail temperature monitoring during tail-flick
test in evaluating the antinociceptive action of volatile
anesthetics.
Sawamura S, Tomioka T, Hanaoka K
Department of Anesthesiology, Tokyo University, Japan.
[Medline record in process]
BACKGROUND: Tail-flick (TF) latency can be influenced by
tail-skin temperature (TT), and treatments that raise TT
can mimic hyperalgesia on a TF test. As volatile anesthetics
can raise TT via heat redistribution, their antinociceptive
action can be hidden or obscured in a TF test. We tested
the hypothesis that TT monitoring improves the efficiency
of TF tests in evaluating the antinociceptive action of
volatile anesthetics. METHODS: The relationship between
TT and TF latency was first explored under varied TTs in
12 rats. Then, TT and TF latency were measured before and
during isoflurane exposure (1.2%). In the low temperature
group (n=6), rats were prewarmed mildly to increase TT during
isoflurane exposure. In the high temperature group (n=6),
rats were prewarmed enough to prevent a TT increase during
isoflurane exposure. RESULTS: There was a highly significant
correlation between TT and TF latency, that is, TF latency
decreased as TT increased. In the low temperature group,
there was a significant increase in TT during isoflurane
exposure, while an increase in TF latency did not reach
statistical significance. Tail-flick latency corrected by
a change in TT showed a significant increase. In the high
temperature group, TF latency increased significantly during
isoflurane exposure without an increase in TT. CONCLUSIONS:
Isoflurane inhalation can induce an increase in TT, which
can obscure its antinociceptive action as evaluated by a
TF test. Monitoring TT during a TF test is important to
efficiently evaluate the antinociceptive action of volatile
anesthetics.
PMID: 11952449, UI: 21949469
Acta Anaesthesiol Scand 2002 Apr;46(4):441-6
Effect of delayed supine positioning after induction of
spinal anaesthesia for caesarean section.
Kohler F, Sorensen JF, Helbo-Hansen HS
Department of Anesthesiology and Intensive Care Medicine,
Odense University Hospital, Denmark.
[Medline record in process]
BACKGROUND: The study tested the hypothesis that the incidence
of hypotension during spinal anaesthesia for caesarean section
is less in parturients who remain in the sitting position
for 3 min compared with parturients who are placed in the
modified supine position immediately after induction of
spinal anesthesia. METHODS: Spinal anaesthesia was induced
with the woman in the sitting position using 2.8 ml hyperbaric
bupivacaine 0.5% at the L3-4 or L2-3 interspace. Ninety-eight
patients scheduled for elective caesarean section under
spinal anaesthesia were randomised to assume the supine
position on an operating table tilted 10 degrees to the
left (modified supine position) immediately after spinal
injection (group 0, n=52) or to remain in the sitting position
for 3 min before they also assumed the modified supine position
(group 3, n=46). Isotonic saline 2-300 ml was given intravenously
over 15 min before spinal injection followed by 15 ml/kg
over 15-20 min after induction of spinal anaesthesia. If
the systolic blood pressure decreased to less than 70% of
baseline or to less than 100 mmHg or if there was any complaint
of nausea, ephedrine was given in 5 mg boluses intravenously
every 2 min. RESULTS: The blood pressure decreased significantly
in both groups following spinal injection (P<0.001).
Blood pressure variations over time differed significantly
between the two groups (P<0.05). However, the incidence
of maternal hypotension before delivery was similar in the
two groups. The difference was caused by the time to the
blood pressure nadir being significantly shorter in group
0 compared with group 3 (9.1+/-4.5 min vs. 11.7+/-3.7 min,
P<0.01). Similar numbers of patients received rescue
with ephedrine before delivery: 35 (67%) in group 0 vs.
26 (57%) in group 3 (NS). The mean total dose of ephedrine
before delivery was 10.9 mg in group 0 vs. 9.2 mg in group
3 (NS). There were no differences in neonatal outcome between
the two groups. CONCLUSION: At elective caesarean section,
a 3-min delay before supine positioning does not influence
the incidence of maternal hypotension after induction of
spinal anaesthesia in the sitting position with 2.8 ml of
bupivacaine 0.5% with 8% dextrose.
PMID: 11952447, UI: 21949467
Acta Anaesthesiol Scand 2002 Apr;46(4):435-40
Comparison between intra-articular bupivacaine with epinephrine
and epinephrine alone on short-term and long-term pain after
knee arthroscopic surgery under general anesthesia in day-surgery
patients.
Toivonen J, Pitko VM, Rosenberg PH
Departments of Anesthesia and Surgery, South Carelian Central
Hospital, Lappeenranta, and Department of Anesthesiology
and Intensive Care Medicine, Helsinki University Hospital,
Helsinki, Finland.
[Medline record in process]
BACKGROUND: : Postarthroscopy analgesia has been provided
with intra-articular bupivacaine, but reported results are
conflicting regarding efficacy and the duration of analgesia.
The immediate and long-term effects of intra-articular bupivacaine
with epinephrine after arthroscopic knee surgery were therefore
studied in a day surgery setting. METHODS: : 120 ASA I-II
patients scheduled for arthroscopic knee surgery were given
general anesthesia with spontaneous breathing via a laryngeal
mask. In a randomized and blinded fashion half of them received,
at the end of surgery, intra-articularly 20 mL 0.5% bupivacaine
with epinephrine (B + E-group) and the other half 20 mL
saline with epinephrine (S + E-group). All patients received
ketoprofen 100 mg i.v. during surgery and another 100 mg
2-3 h postoperatively. The patients were observed for about
4.5 h in the day surgery unit before discharge. RESULTS:
: The results showed that in comparison with the S + E-group,
significantly fewer patients in the B + E-group needed analgesics
(P < 0.0001) and the amount required was also significantly
less postoperatively, before discharge (about 4.5 h postoperatively)
(P < 0.0001). The latency to the need for the first postoperative
analgesic was shorter in the S + E-group patients (P <
0.0001). At home, during seven days after discharge, the
need for analgesic (oral ketoprofen 100 mg) was greater
in the B + E-group (P < 0.05), especially only during
the second postoperative day, but the visual analoque pain
scale (VAPS) scores were low with no differences between
the groups. No complication occurred. CONCLUSION: : It is
concluded that a good postoperative pain control of intra-articular
bupivacaine with epinephrine was found only in the immediate
postoperative period (i.e. before discharge) in a day-surgery
arthroscopic knee surgery patients.
PMID: 11952446, UI: 21949466
Acta Anaesthesiol Scand 2002 Apr;46(4):384-389
Serum concentration of S-100 protein in assessment of
cognitive dysfunction after general anesthesia in different
types of surgery.
Linstedt U, Meyer O, Kropp P, Berkau A, Tapp E, Zenz M
Department of Anesthesiology, Intensive Care Medicine and
Pain Therapy, University Hospital Bergmannsheil, Ruhr-University
Bochum, Institute of Medical Psychology and Department of
Anesthesiology and Intensive Care Medicine, Christian-Albrechts-University
of Kiel, Germany.
[Record supplied by publisher]
BACKGROUND: S-100 protein serum concentration (S-100) serves
as a marker of cerebral ischemia in cardiac surgery, head
injury and stroke. In these circumstances S-100 corresponds
well with the results of neuropsychological tests. The aim
of the present study was to investigate the value of S-100
and neuron specific enolase (NSE) in reflecting postoperative
cognitive deficit (POCD) after general surgical procedures.
METHODS: One hundred and twenty patients undergoing vascular,
trauma, urological or abdominal surgery were investigated.
Serum values of S-100 and NSE were determined preoperatively
and 0.5, 4, 18 and 36 h postoperatively. Neuropsychological
tests for detecting POCD were performed preoperatively and
on day 1, 3, and 6 after the operation. A decline of more
than 10% in neuropsychological test results was regarded
as POCD. Furthermore, we retrospectively compared the S-100
in patients with and without POCD in different types of
surgery. RESULTS: ACCORDING TO OUR DEFINITION, FORTY: -eight
patients had POCD (95% confidence interval: 37.5-58.5).
These patients showed higher serum concentrations of S-100
(median 024 ng/ml; range 0.01-3.3 ng/ml) compared with those
without POCD (n=69; median 0.14 ng/ml; range 0-1.34 ng/ml)
30 min postoperatively (P=0.01). Neuron specific enolase
was unchanged during the course of the study. Differences
of S-100 in patients with and without POCD were found in
abdominal and vascular surgery but not in urological surgery.
CONCLUSION: When all patients are pooled, S-100 appears
to be suitable in the assessment of incidence, course and
outcome of cognitive deficits. We suspect that in some surgical
procedures, such as urological surgery, S-100 appears to
be of limited value in detecting POCD. Neuron specific enolase
did not reflect neuropsychological dysfunction after noncardiac
surgery.
PMID: 11952437
Acta Anaesthesiol Scand 2002 Apr;46(4):378-83
Increased synthesis of nitric oxide in rat brain cortex
due to halogenated volatile anesthetics confirmed by EPR
spectroscopy.
Baumane L, Dzintare M, Zvejniece L, Meirena D, Lauberte
L, Sile V, Kalvinsh I, Sjakste N
Latvian Institute of Organic Synthesis, Riga, and Faculty
of Medicine, University of Latvia, Riga, Latvia.
[Medline record in process]
BACKGROUND: : Halogenated volatile anesthetics (HVAs) are
considered to be inhibitors of nitric oxide synthase (NOS).
On other hand, NO mediates the vasodilation produced by
HVAs. Thus, both increase and decrease of NO concentration
in brain tissues are possible during anesthesia. Previously,
we have observed an increase of NO content in rat brain
cortex under halothane anesthesia. The goal of this study
was to determine whether the observed phenomenon was general
for this anesthetic group, if it was specific for brain
cortex, and if the NO increase was due changes in NOS activity.
METHODS: : NO scavengers were injected to adult rats 30
min prior to anesthesia. Rats were anesthetized by inhalation
of an O2 mixture with volatile anesthetics (1.5% for halothane;
1% for isoflurane, 2% for sevoflurane). After 30 min of
anesthesia, rats were decapitated and brain cortex, cerebellum,
liver, heart, kidneys and testes were dissected, frozen
in liquid nitrogen and subjected to EPR spectroscopy. Nitric
oxide content was determined quantitatively based on the
intensity of the NO-Fe-DETC complex spectrum and its comparison
with the calibration curve. RESULTS: : In rats anesthetized
with HVAs, we observed a greater than twofold increase of
NO content in brain cortex as compared to the nonanesthetized
animals. No significant changes were detected in other organs.
The NOS inhibitor Nomega-nitro-L-arginine abolished the
increase of NO content in brain produced by volatile anesthetics.
CONCLUSION: : The action of volatile anesthetics is coupled
with an increase of NO content in the cortex dependent on
NOS activity.
PMID: 11952436, UI: 21949456
Anesth Analg 2002 Apr;94(4):1042-3
Hiccupping and regurgitation via the drain tube of the
ProSeal laryngeal mask.
Borromeo CJ, Canes D, Stix MS, Glick ME
Publication Types:
Letter
PMID: 11916825, UI: 21914030
Anesth Analg 2002 Apr;94(4):1036-9, table of contents
Esophageal insufflation with normal fiberoptic positioning
of the ProSeal laryngeal mask airway.
Stix MS, Borromeo CJ, O'Connor CJ Jr
Department of Anesthesiology, Lahey Clinic, Burlington,
Massachusetts 01805, USA. michael.s.stix@lahey.org
IMPLICATIONS: Esophageal insufflation can occur simultaneously
with venting from the drain tube during positive pressure
ventilation with the ProSeal laryngeal mask airway.
PMID: 11916820, UI: 21914025
Anesth Analg 2002 Apr;94(4):1001-6, table of contents
Continuous three-in-one block for postoperative pain after
lower limb orthopedic surgery: where do the catheters go?
Capdevila X, Biboulet P, Morau D, Bernard N, Deschodt
J, Lopez S, d'Athis F
Department of Anesthesia and Intensive Care Medicine, Lapeyronie
University Hospital, Montpellier, France. x-capdevilla@chu-montpellier.fr
Continuous three-in-one block is widely used for postoperative
analgesia after proximal lower limb surgery, but location
of the catheter has not been well addressed in the literature.
We prospectively studied, in 100 patients, the characteristics
of catheter threading under the iliac fascia and the correlations
between catheter tip location and effective sensory and
motor blockade of the three principal nerves of the lumbar
plexus. Postoperatively, in conscious patients, 16 to 20
cm of a catheter was placed in the fascial sheath after
femoral nerve location with a nerve stimulator. Contrast
media (3 mL Iopamidol 390) was injected, and the catheter
tip was located by means of an anteroposterior pelvic radiograph.
An equal-volume mixture of 0.5% bupivacaine/2% lidocaine
with epinephrine (30 mL) was injected through the catheter.
Patient and catheter-insertion characteristics were noted.
Thirty minutes after injection, sensory blockade was evaluated
in the cutaneous territories of the lateral femoral cutaneous,
femoral, and obturator nerves, along with motor blockade
of the last two nerves. Pain scores at 30 min were also
recorded. Seven block failures were noted. The tip of the
catheter reached the lumbar plexus (Group 1) in 23% of the
patients and lay deep to the medial (Group 2) or lateral
(Group 3) part of the fascia iliaca in 33% and 37% of the
patients, respectively. Demographic data and catheter threading
characteristics were comparable among the groups. A three-in-one
block was noted in 91% of Group 1 patients, but in only
52% and 27% of Group 2 and 3 patients, respectively (P <
0.05). Comparing Group 2 and 3 patients, sensory block was
achieved in respectively 100% and 94% for the femoral nerve,
52% and 94% for the lateral femoral cutaneous nerve (P <
0.05), and 82% and 27% for the obturator nerve (P < 0.05).
Visual analog scale pain scores on movement were significantly
lower in Group 1 patients (P < 0.05). We conclude that
during a continuous three-in-one block, the threaded catheter
rarely reached the lumbar plexus. The quality of sensory
and motor blockade and initial pain relief depend on the
location of the catheter tip under the fascia iliaca. IMPLICATIONS:
The course of a continuous three-in-one block catheter is
unpredictable. Only 23% of the catheters lie near the lumbar
plexus. The success of sensory and motor blocks, as well
as postoperative analgesia, depend on the position of the
catheter under the fascia iliaca.
PMID: 11916812, UI: 21914017
Anesth Analg 2002 Apr;94(4):996-1000, table of
contents
Postoperative analgesia with continuous sciatic nerve
block after foot surgery: a prospective, randomized comparison
between the popliteal and subgluteal approaches.
di Benedetto P, Casati A, Bertini L, Fanelli G, Chelly
JE
Department of Anesthesiology, CTO Roma, Italy.
To compare the posterior popliteal and subgluteal continuous
sciatic nerve block for anesthesia and acute postoperative
pain management after foot surgery, 60 ASA physical status
I and II patients undergoing elective orthopedic foot surgery
were randomly assigned to either a Subgluteal group (n =
30) or Popliteal group (n = 30). Before surgery and after
performing a femoral nerve block with 15 mL of 2% mepivacaine,
we performed the sciatic nerve block with 20 mL of 0.75%
ropivacaine using either a subgluteal or posterior popliteal
approach, and the placement of a catheter came afterward.
In the recovery room, the catheter was connected to a patient-controlled
analgesia pump to infuse 0.2% ropivacaine (basal infusion
rate of 5 mL/h, incremental bolus of 10 mL, and a lockout
time of 60 min). There were no technical problems in catheter
placement. Intraoperative efficacy of nerve block was similar
in the two groups. Postoperative catheter displacement and
occlusion were recorded in four patients in the Popliteal
group and two patients in the Subgluteal group (P = 0.67).
Both approaches provided similar postoperative analgesia.
We conclude that the subgluteal approach is as effective
and safe as the previously described posterior popliteal
approach for continuous sciatic block and can be considered
a useful alternative to anesthesia and acute postoperative
analgesia after foot procedures. IMPLICATIONS: Comparing
two different approaches for continuous sciatic nerve block
after orthopedic foot surgery, this prospective, randomized
study demonstrated that the subgluteal approach is as effective
and safe as the previously described posterior popliteal
approach, and can be considered a useful alternative to
anesthesia and acute postoperative analgesia after foot
procedures.
PMID: 11916811, UI: 21914016
Anesth Analg 2002 Apr;94(4):987-90, table of contents
A double-blinded, randomized comparison of either 0.5%
levobupivacaine or 0.5% ropivacaine for sciatic nerve block.
Casati A, Borghi B, Fanelli G, Cerchierini E, Santorsola
R, Sassoli V, Grispigni C, Torri G
Department of Anesthesiology, Vita-Salute University, IRCCS
H. San Raffaele, Milan, Italy. casati.andrea@hsr.it
To compare intraoperative and postoperative clinical properties
of levobupivacaine and ropivacaine for sciatic nerve block,
50 ASA physical status I and II patients undergoing hallux
valgus repair received a femoral nerve block with 15 mL
of 2% mepivacaine. They were then randomly allocated in
a double-blinded fashion to receive a sciatic nerve block
with either 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine
(n = 25). An independent blinded observer evaluated the
onset time of surgical anesthesia as well as the quality
of the surgical block and postoperative analgesia. The median
(range) onset time of surgical block at the sciatic nerve
distribution was 30 min (5-60 min) with levobupivacaine
and 15 min (5-60 min) with ropivacaine (P = 0.63). Four
patients (two patients in each group) received a supplementary
ankle block by the surgeon just before the beginning of
surgery. All four patients also received IV fentanyl supplementation,
but in three of them, propofol infusion was required to
complete surgery (two in the Levobupivacaine group [8%]
and one in the Ropivacaine group [4%]; P = 0.99). In six
patients of the Levobupivacaine group (24%) and five patients
of the Ropivacaine group (20%), IV fentanyl supplementation
was required to complete surgery (P = 0.99). No differences
in the time to recovery of sensory and motor function were
observed between the two groups, whereas median (range)
duration of postoperative analgesia was 16 h (8-24 h) with
levobupivacaine and 16 h (8-24 h) with ropivacaine (P =
0.83). We conclude that 0.5% levobupivacaine and 0.5% ropivacaine
provide comparable surgical anesthesia and postoperative
analgesia. IMPLICATIONS: No studies have compared the clinical
properties of levobupivacaine with those of ropivacaine
when providing sciatic nerve block for hallux valgus repair.
Results from this prospective, randomized, double-blinded
study demonstrate that 20 mL of either 0.5% levobupivacaine
or 0.5% ropivacaine provide comparable surgical block with
prolonged postoperative analgesia.
Publication Types:
Clinical trial
Randomized controlled trial
PMID: 11916809, UI: 21914014
Anesth Analg 2002 Apr;94(4):863-6, table of contents
The reduction in minimum alveolar concentration for tracheal
extubation after clonidine premedication in children.
Yaguchi Y, Inomata S, Kihara S, Baba Y, Kohda Y, Toyooka
H
Department of Anesthesiology, Institute of Clinical Medicine,
University of Tsukuba, Tsukuba City, Ibaraki, Japan.
The effects of clonidine on minimum alveolar concentration
for tracheal extubation (MAC-ex) have not been elucidated.
Clonidine may lead to prolonged emergence from anesthesia.
We investigated the effects of oral clonidine premedication
on MAC-ex and examined the emergence properties of sevoflurane
in children. Sixty ASA physical status I pediatric patients,
aged from 2 to 9 yr, were randomly divided into one of three
groups and received placebo, clonidine 2 microg/kg, or clonidine
4 microg/kg (n = 20 each) orally, 100 min before the induction
of anesthesia. The induction of anesthesia, tracheal intubation,
and maintenance of anesthesia were performed with sevoflurane
in air and oxygen. MAC-ex was defined according to the modification
of Dixon's up-and-down method, with 0.25% as a step size.
In addition, in the Control and 4 microg/kg groups, the
time from tracheal extubation to spontaneous eye opening
(eye-opening time) and the time from tracheal extubation
to leaving the operating room (awakening time) were recorded.
MAC-ex for sevoflurane (mean +/- SD) was 1.63% +/- 0.13%,
1.04% +/- 0.26%, and 0.66% +/- 0.09% respectively in the
Control group, 2 microg/kg group, and 4 microg/kg group.
Significant differences were observed among the three groups.
The eye-opening times were 5.7 +/- 3.5 min in the Control
group and 5.1 +/- 1.0 min in the 4 microg/kg group. The
awakening times were 9.7 +/- 3.7 min in the Control group
and 9.2 +/- 3.8 min in the 4 microg/kg group. No significant
differences were observed among the groups. IMPLICATIONS:
Oral clonidine premedication decreased MAC for tracheal
extubation for sevoflurane dose dependency and did not prolong
emergence from anesthesia.
Publication Types:
Clinical trial
Randomized controlled trial
PMID: 11916786, UI: 21913991
Anesth Analg 2002 Apr;94(4):859-62, table of contents
Postoperative pain relief in children undergoing tympanomastoid
surgery: is a regional block better than opioids?
Suresh S, Barcelona SL, Young NM, Seligman I, Heffner
CL, Cote CJ
Department of Pediatric Anesthesiology and Division of
Otolaryngology, Children's Memorial Hospital, Northwestern
University Medical School, Chicago, Illinois 60614, USA.
ssureth@northwestern.edu
Peripheral nerve blocks of the surgical site can reduce
the need for perioperative opioids thereby decreasing their
unwanted adverse effects, such as postoperative nausea and
vomiting. In this prospective, randomized, double-blinded
study, we examined the efficacy of a great auricular nerve
(GAN) block compared with IV morphine sulfate in children
undergoing tympanomastoid surgery. After the induction of
general anesthesia, children were randomized to receive
either a GAN block with 2 mL of 0.25% bupivacaine with epinephrine
(1:200,000) and a sham IV injection of 2 mL of saline solution
or a sham GAN block with 2 mL of saline solution with an
IV injection of 0.1 mg/kg morphine sulfate diluted to 2
mL. Patients' objective pain scores were assessed by a blinded
observer and the incidence of vomiting was recorded. The
GAN-Block patients as a group required more pain rescue
in the postanesthesia care unit; this difference was not
statistically different from the IV-morphine group (P =
0.084). Nine GAN-Block patients never received opioid or
other analgesics at any time in the first 24 h after surgery.
The group that received the GAN block also had a less frequent
incidence of vomiting requiring intervention (7 versus 19)
during their entire hospitalization or at home (P = 0.027).
The GAN-Block group also had more patients who never experienced
vomiting (13 of 20 versus 5 of 20, P = 0.026). In this cohort,
a peripheral nerve block decreased the overall incidence
of postoperative vomiting thereby reducing associated costs.
IMPLICATIONS: We prospectively compared the use of a great
auricular nerve block versus IV morphine sulfate in a randomized
double-blinded study in children undergoing tympanomastoid
surgery. Analgesia was comparable between groups but nearly
half the Block group never required additional analgesics
and the number of vomiting events was nearly 66% less.
Publication Types:
Clinical trial
Randomized controlled trial
PMID: 11916785, UI: 21913990
Anesthesiology 2002 Apr;96(4):1023-5
Iliopsoas abscess and persistent radiculopathy: a rare
complication of continuous infusion techniques of epidural
anesthesia.
Aota Y, Onari K, Suga Y
Department of Orthopedic Surgery, Yokohama Minami Kyosai
Hospital, Yokohama City, Kanagawa Prefecture, Japan.
[Medline record in process]
PMID: 11964614, UI: 21961257
Anesthesiology 2002 Apr;96(4):1004-17
Practice guidelines for sedation and analgesia by non-anesthesiologists.
[Medline record in process]
PMID: 11964611, UI: 21961254
Anesthesiology 2002 Apr;96(4):941-6
Preparation of the Siemens KION Anesthetic Machine for
Patients Susceptible to Malignant Hyperthermia.
Petroz GC, Lerman J
Department of Anaesthesia, Hospital for Sick Children,
University of Toronto, Toronto, Ontario, Canada.
[Medline record in process]
BACKGROUND: Preparation of anesthetic machines for use
with malignant hyperthermia-susceptible (MHS) patients requires
that the machines be flushed with clean fresh gas. We investigated
the washout of inhalational anesthetics from the KION anesthetic
machine. METHODS: In part 1, halothane was circulated through
KION anesthetic machines for either 2 or 12 h using a test
lung. The times to washout halothane (to 10 parts per million
[ppm]) first, from the internal circuitry and second, from
the ventilator-patient cassette (without the carbon dioxide
absorber) were determined at 5 and 10 l/min fresh gas flow
(FGF). In part 2, the rates of washout of halothane or isoflurane
from either the KION or Ohmeda Excel 210 machines were compared.
The effluent gases were analyzed using calibrated Datex
Capnomac Ultima (Helsinki, Finland) and a Miran LB2 Portable
Ambient Air Analyzer (Foxboro, Norwalk, CT). RESULTS: Halothane
was washed out of the internal circuitry of the KION within
5 min at 10 l/min FGF. Halothane was eliminated from the
ventilator-patient cassette in 22 min at the same FGF. The
times to reach 10 ppm concentration of halothane and isoflurane
in the KION at 10 l/min FGF, 23 to 25 min, was four-fold
greater than those in the Ohmeda Excel 210, 6 min. CONCLUSIONS:
To prepare the KION anesthetic machine for MHS patients,
the machine without the carbon dioxide absorber must be
flushed with 10 l/min FGF for at least 25 min to achieve
10 ppm anesthetic concentration. This FGF should be maintained
throughout the anesthetic to avoid increases in anesthetic
concentration in the FGF.
PMID: 11964603, UI: 21961246
Anesthesiology 2002 Apr;96(4):893-906
Mechanisms underlying greater sensitivity of neonatal
cardiac muscle to volatile anesthetics.
Prakash YS, Seckin I, Hunter LW, Sieck GC
Departments of Anesthesiology and Physiology & Biophysics,
Mayo Clinic and Foundation, Rochester, Minnesota.
[Medline record in process]
BACKGROUND: In neonatal heart, plasma membrane Na+-Ca2+
exchange (NCX) and Ca2+ influx channels play greater roles
in intracellular Ca2+ concentration [Ca2+]i regulation compared
with the sarcoplasmic reticulum (SR). In neonatal (aged
0-3 days) and adult (aged 84 days) rat cardiac myocytes,
we determined the mechanisms underlying greater sensitivity
of the neonatal myocardium to inhibition by volatile anesthetics.
METHODS: The effects of 1 and 2 minimum alveolar concentration
halothane and sevoflurane on Ca2+ influx during electrical
stimulation in the presence or blockade of NCX and the Ca2+
channel agonist BayK8644 were examined. [Ca2+]i responses
to caffeine were used to examine anesthetic effects on SR
Ca2+ release (via ryanodine receptor channels) and reuptake
(via SR Ca2+ adenosine triphosphatase). Ca2+ influx via
NCX was examined during rapid activation in the presence
of the reversible SR Ca2+ adenosine triphosphatase inhibitor
cyclopiazonic acid and ryanodine to inhibit the SR. Efflux
mode NCX was examined during activation by extracellular
Na+ in the absence of SR reuptake. RESULTS: Intracellular
Ca2+ concentration transients during electrical stimulation
were inhibited to a greater extent in neonates by halothane
(80%) and sevoflurane (50%). Potentiation of [Ca2+]i responses
by BayK8644 (160 and 120% control in neonates and adults,
respectively) was also blunted by anesthetics to a greater
extent in neonates. [Ca2+]i responses to caffeine in neonates
( approximately 30% adult responses) were inhibited to a
lesser extent compared with adults (35 vs. 60% by halothane).
Both anesthetics inhibited Ca2+ reuptake at 2 minimum alveolar
concentration, again to a greater extent in adults. Reduction
in NCX-mediated influx was more pronounced in neonates (90%)
compared with adults (65%) but was comparable between anesthetics.
Both anesthetics also reduced NCX-mediated efflux to a greater
extent in neonates. Potentiation of NCX-mediated Ca2+ efflux
by extracellular Na+ and NCX-mediated Ca2+ influx by intracellular
Na+ were both prevented by halothane, especially in neonates.
CONCLUSIONS: These data indicate that greater myocardial
depression in neonates induced by volatile anesthetics may
be mediated by inhibition of NCX and Ca2+ influx channels
rather than inhibition of SR Ca2+ release.
PMID: 11964597, UI: 21961240
Anesthesiology 2002 Apr;96(4):835-40
Usefulness of Nitric Oxide Treatment for Pulmonary Hypertensive
Infants during Cardiac Anesthesia.
Kadosaki M, Kawamura T, Oyama K, Nara N, Wei J, Mori N
Departments of Anesthesiology and Pediatric Cardiology,
Iwate Medical University Memorial Heart Center, Iwate, Japan.
[Medline record in process]
BACKGROUND: The beneficial effect of inhaled nitric oxide
(NO) on pulmonary hypertension is well known. However, the
indications for NO inhalation therapy for pulmonary hypertension
associated with congenital heart lesions are still unclear.
The aim of the current study was to seek a measure that
would predict the effectiveness of inhaled NO in infants
undergoing cardiac surgery. METHODS: Forty-six infants with
pulmonary hypertension were studied. Pulmonary vascular
resistance (PVR) measured at the time of cardiac catheterization
was used as an indicator and compared with pulmonary arterial
pressure/systemic blood pressure ratio (Pp/Ps) at the time
of weaning from cardiopulmonary bypass. The effect of 40
ppm of inhaled NO for 15 min was evaluated in patients whose
Pp exceeded systemic values. RESULTS: Preoperative PVR correlated
positively with Pp/Ps at the time of weaning from cardiopulmonary
bypass (r2 = 0.86; P < 0.05; n = 46). A Pp/Ps greater
than or equal to 1 was not observed in any cases in which
the preoperative PVR values were less than 7 Wood units
m2; Pp/Ps ratio greater than or equal to 1 occurred in four
patients. Each of these had PVR values greater than 7 Wood
units m2. Three of these patients who had PVR values in
the 7-12 Wood units m2 range were responsive to inhaled
NO. The fourth patient, whose PVR value was greater than
15 Wood units m2, was unresponsive. Lung biopsy specimens
were obtained in two patients whose preoperative PVR values
were greater than 10 Wood units m2. CONCLUSION: Preoperative
PVR correlates reasonably well with postbypass Pp/Ps.
PMID: 11964589, UI: 21961232
Anesthesiology 2002 Apr;96(4):803-16
Performance of the ARX-derived auditory evoked potential
index as an indicator of anesthetic depth: a comparison
with bispectral index and hemodynamic measures during propofol
administration.
Struys MM, Jensen EW, Smith W, Smith NT, Rampil I, Dumortier
FJ, Mestach C, Mortier EP
Department of Anesthesia, University Hospital of Gent,
Gent, Belgium. Michel.Struys@rug.ac.be
[Medline record in process]
BACKGROUND: Autoregressive modeling with exogenous input
of middle-latency auditory evoked potential (A-Line autoregressive
index [AAI]) has been proposed for monitoring anesthetic
depth. The aim of the current study was to compare the accuracy
of this new index with the Bispectral Index (BIS), predicted
effect-site concentration of propofol, and hemodynamic measures.
METHODS: Twenty female patients scheduled for ambulatory
gynecologic surgery received effect compartment controlled
infusion of propofol. Target effect-site concentration was
started at 1.5 microg/ml and increased every 4 min by 0.5
microg/ml. At every step, sedation level was compared with
monitoring values using different clinical scoring systems
and reaction to noxious stimulus. RESULTS: Bispectral Index,
AAI, and predicted propofol effect-site concentration were
accurate indicators for the level of sedation and loss of
consciousness. Hemodynamic variables were poor indicators
of the hypnotic-anesthetic status of the patient. BIS correlated
best with propofol effect-site concentration, followed by
AAI. Hemodynamic measurements did not correlate well. No
indicators predicted reaction to noxious stimulus. Poststimulus,
BIS and AAI showed an increase as a result of arousal. This
reaction occurred more rapidly with the AAI than with BIS.
CONCLUSION: Bispectral Index, AAI, and predicted propofol
effect-site concentration revealed information on the level
of sedation and loss of consciousness but did not predict
response to noxious stimulus.
PMID: 11964586, UI: 21961229
Anesthesiology 2002 Apr;96(4):784-7
Monitors of depth of anesthesia, quo vadis?
Kalkman CJ, Drummond JC
[Medline record in process]
Publication Types:
Editorial
PMID: 11964583, UI: 21961226
Anesthesiology 2002 Apr;96(4):5A-6A
This month in anesthesiology.
Henkel G
[Medline record in process]
Publication Types:
Editorial
PMID: 11964581, UI: 21961224
Anesthesiology 2002 Apr;Suppl:70 pages
Society for Obstetric Anesthesia and Perinatology 34th
Annual Meeting. May 1-5, 2002, Hilton Head Island, South
Carolina, USA. Abstracts.
Department of Anesthesiology, Orthopedic University Clinic
Zurich/Balgrist, Zurich, Switzerland.
PMID: 11873056, UI: 21861200
Anesthesiology 2002 Mar;96(3):755-6
High gastric output as a perioperative sign of carcinoid
syndrome.
Pandharipande PP, Reichard PS, Vallee MF
Anesthesiology, Vanderbilt University, Nashville, Tennessee,
USA.
PMID: 11873054, UI: 21861198
Anesthesiology 2002 Mar;96(3):742-52
Practice guidelines for postanesthetic care: a report
by the American Society of Anesthesiologists Task Force
on Postanesthetic Care.
Publication Types:
Guideline
PMID: 11873052, UI: 21861196
Anesthesiology 2002 Mar;96(3):607-11
Morphologic changes in the upper airway of children during
awakening from propofol administration.
Litman RS, Weissend EE, Shrier DA, Ward DS
Department of Anesthesiology, Division of Pediatric Anesthesia,
University of Rochester School of Medicine and Dentistry,
New York, USA. litmanr@email.chop.edu
BACKGROUND: The purpose of this study was to determine
the morphologic changes that occur in the upper airway of
children during awakening from propofol sedation. METHODS:
Children undergoing magnetic resonance imaging of the head
underwent additional scans of the upper airway during deep
sedation with propofol; this was repeated on awakening.
Axial views were obtained at the most posterior sites of
the pharynx at the levels of the soft palate and tongue.
Measurements were then obtained of the anterior-posterior
(A-P) diameter, transverse diameter, and cross-sectional
areas at these levels. RESULTS: Data were obtained on 16
children, aged 10 months to 7 yr. In both sedated and awakening
states, most children had the smallest cross-sectional area
of the pharynx at the level of the soft palate. During the
sedated state, at the soft palate level, the transverse
diameter was most narrow in 11 children, the A-P diameter
was most narrow in 1 child, and they were equal in 2 children.
During the sedated state, at the level of the tongue, the
transverse diameter was most narrow in 9 children, the A-P
diameter was most narrow in 5 children, and they were equal
in 2 children. During awakening, at the soft palate level,
the transverse diameter was most narrow in none of the children,
the A-P diameter was most narrow in 13 children, and they
were equal in 1 child. At the level of the tongue, the transverse
diameter was most narrow in 4 children, and the A-P diameter
was most narrow in 12 children. During awakening, the A-P
diameter of the pharynx at the level of the soft palate
decreased in 12 children, increased in 1 child, and remained
the same in 1 child. (P < 0.001). The transverse diameter
increased in 11 children, decreased in 1 child, and remained
the same in 2 children (P = 0.001). The cross-sectional
area at the level of the soft palate increased in 4 children,
decreased in 8 children, and stayed the same in 2 children
(P = 0.5). During awakening, the A-P diameter of the pharynx
at the level of the tongue decreased in 11 children, increased
in 4 children, and remained the same in 1 child. (P = 0.01).
The transverse diameter increased in 11 children and decreased
in 5 children (P = 0.07). The cross-sectional area at the
level of the tongue increased in 7 children, decreased in
7 children, and stayed the same in 2 children (P = 0.9).
CONCLUSIONS: The dimensions of the upper airways of children
change shape significantly on awakening from propofol sedation.
When sedated, the upper airway is oblong shaped, with the
A-P diameter larger than the transverse diameter. On awakening,
the shape of the upper airway in most children changed such
that the transverse diameter was larger. Cross-sectional
areas between sedated and awakening states were unchanged.
These changes may reflect the differential effects of propofol
on upper airway musculature during awakening.
Publication Types:
Clinical trial
PMID: 11873035, UI: 21861179
Anesthesiology 2002 Mar;96(3):600-6
Impact of shorter-acting neuromuscular blocking agents
on fast-track recovery of the cardiac surgical patient.
Department of Anesthesia, Evanston Northwestern Healthcare,
Evanston, Illinois 60201, USA. dgmurphy@core.com
BACKGROUND: Residual paralysis associated with the use
of long-acting muscle relaxants can delay recovery from
anesthesia and surgery. The authors tested the hypothesis
that use of shorter-acting neuromuscular blocking agents
is associated with reductions in tracheal extubation times
and intensive care unit (ICU) length of stay in patients
undergoing cardiac surgery with cardiopulmonary bypass.
METHODS: One hundred ten patients scheduled for elective
coronary artery bypass grafting or single valve surgery
were randomized prospectively to receive either pancuronium
or rocuronium intraoperatively. Anesthetic management and
muscle relaxant maintenance dosing were standardized. In
the ICU, the time required to wean ventilatory support,
the duration of tracheal intubation, and length of stay
were recorded. Subjects were asked to quantify generalized
muscle weakness as they awakened in the ICU and again after
tracheal extubation. RESULTS: Complete data were collected
on 51 patients in the pancuronium group and 52 patients
in the rocuronium group. No differences were found between
the groups in anesthetic, surgical, or ICU management. Significant
increases in the duration of weaning of ventilatory support
were observed in patients who received pancuronium (median,
180 min; range, 50-780 min) compared with the rocuronium
group (median, 110 min; range, 45-250 min). Tracheal extubation
was significantly delayed in the pancuronium group (median,
500 min; range, 240-1,305 min) compared with the rocuronium
group (median, 350 min; range, 210-1,140 min). Subjects
in the pancuronium group experienced more mild to severe
weakness in the ICU. However, the choice of muscle relaxant
did not influence ICU length of stay. CONCLUSION: The use
of shorter-acting neuromuscular blocking agents in patients
undergoing cardiac surgery with cardiopulmonary bypass is
associated with reductions in tracheal extubation times
and symptoms of residual paresis.
Publication Types:
Clinical trial
Randomized controlled trial
PMID: 11873034, UI: 21861178
Anesthesiology 2002 Mar;96(3):583-7
The relationship between acceleromyographic train-of-four
fade and single twitch depression.
Kopman AF, Klewicka MM, Neuman GG
Department of Anesthesiology, New York Medical College,
Valhalla, New York, USA. akopman@rcn.com
BACKGROUND: During offset of nondepolarizing neuromuscular
block, a train-of-four (TOF) fade ratio of 0.70 or greater
is considered to reliably indicate the return of single
twitch height (T1) to its control value. Studies using mechanomyography
or electromyography confirm this observation. The authors'
impressions when using the acceleromyograph as a neuromuscular
monitor did not support these results. Therefore, the authors
studied the relation between T1 and the TOF ratio (when
measured by acceleromyography) during recovery from neuromuscular
block. METHODS: Sixteen adult patients were studied. Anesthesia
was induced with intravenous opioid plus 2.0-2.5 mg/kg propofol.
Laryngeal mask placement or tracheal intubation was accomplished
without the use of muscle relaxants. Anesthesia was maintained
with nitrous oxide, desflurane (2.0-3.0%, end-tidal), and
fentanyl. The response of the thumb to ulnar nerve stimulation
was recorded with the TOF-Guard acceleromyograph (Organon
Teknika BV, Boxtel, The Netherlands). TOFs were administered
every 15 s. After final calibration, 0.15 mg/kg mivacurium
was administered. No further relaxants were administered.
T1 and the TOF ratio were then recorded until the TOF ratio
had returned to its initial value (+/- 5%). RESULTS: At
a TOF ratio of 0.70 (during recovery of neuromuscular function),
T1 averaged only 69 +/- 8% of control. At a TOF ratio of
0.90, T1 averaged 86 +/- 5% of control. To achieve 90% recovery
of T1, a TOF ratio of 0.93 +/- 0.08 was required. CONCLUSION:
Assumptions regarding the relation between T1 and the TOF
ratio derived from studies using mechanomyography and electromyography
do not necessarily apply to observations obtained using
acceleromyography.
Publication Types:
Clinical trial
PMID: 11873031, UI: 21861175
Anesthesiology 2002 Mar;96(3):552-4
Inability to consistently elicit a motor response following
sensory paresthesia during interscalene block administration.
Urmey WF, Stanton J
Department of Anesthesiology, Hospital for Special Surgery,
Weill Medical College of Cornell University, New York, New
York 10021, USA. urmeyw@hss.edu
BACKGROUND: Two methods of nerve block based on eliciting
neural feedback with the block needle currently exist. The
paresthesia technique uses sensory feedback to ascertain
that the needle tip is close to the nerve. By contrast,
a peripheral nerve stimulator makes use of motor responses
to electrical stimulation. The relation of motor responses
to an electrical peripheral nerve stimulator and sensory
nerve contact (paresthesia) had not been studied. METHODS:
Thirty consecutive unpremedicated patients who presented
for shoulder surgery with interscalene block anesthesia
were prospectively studied. Interscalene block was performed
by the single paresthesia method of Winnie, using an insulated
or non-insulated needle connected to a peripheral nerve
stimulator with the power off. At the precise point of paresthesia,
the peripheral nerve stimulator was turned on, and the current
was slowly increased to 1.0 mA with a pulse width of 0.2
ms. Presence and location of any motor responses were observed
and recorded. RESULTS: All patients had easily elicited
paresthesias. The site of first paresthesia was to the shoulder
in 73% of patients. Only 30% of patients exhibited any motor
response to electrical stimulation up to 1.0 mA. There was
no relation between site of paresthesia and associated motor
nerve response. CONCLUSION: Elicitation of paresthesia does
not translate to an ability to elicit a motor response to
a peripheral nerve stimulator in the majority of patients.
Publication Types:
Clinical trial
PMID: 11873027, UI: 21861171
Anesthesiology 2002 Mar;96(3):542-5
Chronobiology of epidural ropivacaine: variations in the
duration of action related to the hour of administration.
Debon R, Chassard D, Duflo F, Boselli E, Bryssine B, Allaouchiche
B
Department of Anesthesiology and Intensive Care, Hotel-Dieu
Hospital, Lyon, France.
BACKGROUND: A temporal pattern of the kinetics of local
anesthetics is demonstrated in dental and skin anesthesia,
with an important variation in the duration of action related
to the hour of administration. The aim of this study is
to determine whether the hour of injection influences the
duration of epidurally administered ropivacaine during labor.
METHODS: One hundred ninety-four women in the first stage
of labor were assigned to one of four groups throughout
the day period: group 1 (night: from 1:01 to 7:00 am), group
2 (morning: from 7:01 am to 1:00 pm), group 3 (afternoon:
from 1:01 to 7:00 pm), and group 4 (evening: from 7:01 pm
to 1:00 am). Each patient received 14 ml ropivacaine, 0.17%,
epidurally, and analgesia duration was measured. RESULTS:
Pain assessed by a visual analog score was not differ-ent
among groups before the first injection of local anesthetic.
Analgesia duration was greater in the diurnal period (group
2: 110 +/- 25 min and group 3: 117 +/- 23 min) compared
with the nocturnal period (group 1: 94 +/- 23 min and group
4: 91 +/- 23 min) (P < 0.01). The largest intraday variation
of analgesia duration among groups reached 28%. CONCLUSIONS:
Epidural analgesia duration exhibits a temporal pattern
with important differences among diurnal and nocturnal phases.
The authors emphasize that the lack of consideration of
the chronobiologic conditions in epidural analgesia studies
may create significant statistical bias. Future studies
dealing with epidural local anesthetics should consider
the time of drug administration.
Publication Types:
Clinical trial
PMID: 11873025, UI: 21861169
Br J Anaesth 2002 Feb;88(2):288-91
Submental intubation in a patient with beta-thalassaemia
major undergoing elective maxillary and mandibular osteotomies.
Mak PH, Ooi RG
Department of Anaesthesiology, Queen Mary Hospital, Pokfulam,
Hong Kong, People's Republic of China.
A 33-yr-old woman with marked maxillo-facial deformities
as a result of underlying beta-thalassaemia major was to
undergo corrective maxillary and mandibular osteotomies.
The placement of an endotracheal tube posed a problem in
this patient because of anatomical deformities in her nasal
passage, surgical constraints on using the oral route, and
reluctance of the patient to have a tracheostomy. This case
report describes the use of a submental tracheal intubation
technique, and the associated anaesthetic difficulties encountered
in patients with this pathology.
PMID: 11883389, UI: 21867449
Br J Anaesth 2002 Feb;88(2):234-40
Comparison of predictive models for postoperative nausea
and vomiting.
Apfel CC, Kranke P, Eberhart LH, Roos A, Roewer N
Department of Anaesthesiology, Julius Maximilians University,
Wurzburg, Germany.
BACKGROUND: In order to identify patients who would benefit
from prophylactic amtiemetics, six predictive models have
been described for the risk assessment of postoperative
nausea and vomiting (PONV). This study compared the validity
and practicability of these models in patients undergoing
general anaesthesia. METHODS: Data were analysed from 1566
patients who underwent balanced anaesthesia without prophylactic
antiemetic treatment for various types of surgery. A systematic
literature search identified six predictive models for PONV.
These models were compared with respect to validity (discriminating
power and calibration characteristics) and practicability.
Discriminating power was measured by the area under the
receiver operating characteristic curve (AUC) and calibration
was assessed by weighted linear regression analysis between
predicted and actual incidences of PONV. Practicability
was assessed according to the number of factors to be considered
for the model (the fewer factors the better), and whether
the score could be used in combination with a previously
applied cost-effective concept. RESULTS: The incidence of
PONV was 600/1566 (38.1%). The discriminating power (AUC)
obtained by the models (named according to the first author)
using the risk classes from the recommended prophylactic
concept were as follows: Apfel, 0.68; Koivuranta, 0.66;
Sinclair, 0.66; Palazzo, 0.63; Gan, 0.61; Scholz, 0.61.
For four models, the following calibration curves (expressed
as the slope and the offset) were plotted: Apfel, y=0.82x+0.01,
r2=0.995; Koivuranta, y=1.13x-0.10, r2=0.999; Sinclair,
y=0.49x+0.29, r2=0.789; Palazzo, y=0.30x+0.30, r2=0.763.
The numbers of parameters to be considered were as follows:
Apfel, 4; Koivuranta, 5; Palazzo, 5; Scholz, 9; Sinclair,
12; Gan, 14. CONCLUSION: The simplified risk scores provided
better discrimination and calibration properties compared
with the more complex risk scores. Therefore, simplified
risk scores can be recommended for antiemetic strategies
in clinical practice as well as for group comparisons in
randomized controlled antiemetic trials.
Publication Types:
Review
Review, tutorial
Validation studies
PMID: 11883387, UI: 21867439
Br J Anaesth 2001 Dec;87(6):942; discussion 942
Numbness a greater problem than pain?
Hatfield A
Publication Types:
Letter
PMID: 11878705, UI: 21867493
Br J Anaesth 2001 Dec;87(6):885-9
Difference in sensitivity to vecuronium between patients
with ocular and generalized myasthenia gravis.
Itoh H, Shibata K, Nitta S
Department of Anesthesiology and Intensive Care Medicine,
Kanazawa University School of Medicine, Japan.
Patients with myasthenia gravis show sensitivity to non-depolarizing
neuromuscular blocking drugs, but little is known about
differences in this sensitivity between types of myasthenia.
In 10 patients with ocular myasthenia gravis and 10 with
generalized myasthenia gravis, twitch tension was monitored
in the adductor pollicis muscle by supramaximal train-of-four
stimulation of the ulnar nerve during anaesthesia with sevoflurane
2.5% and nitrous oxide 60%. After baseline measurement,
an initial dose of vecuronium 10 microg kg(-1) was given.
When the twitch height stabilized (maximum block after the
first 10 microg kg(-1)), the next incremental dose of 10
microg kg(-1) was given and repeated until block, defined
as [1-(first twitch/baseline first twitch)] x 100 reached
90%. Maximum block after the first dose of vecuronium in
ocular patients was significantly less than that in generalized
patients (median 51 vs 91%; P<0.05). Onset of block after
the first dose of vecuronium was significantly slower in
ocular than in generalized myasthenic patients (mean 300
vs 200 s; P<0.05). Doses required to attain a block of
90% or more were significantly higher in ocular than in
generalized patients (median 20 vs 10 microg kg(-1); P<0.05).
Clinicians should consider the type of disease according
to the Osserman classification when using non-depolarizing
neuromuscular. blocking drugs in patients with myasthenia
gravis.
PMID: 11878691, UI: 21867479
Br J Anaesth 2001 Dec;87(6):827-33
Cardioventilatory coupling in heart rate variability:
methods for qualitative and quantitative determination.
Galletly D C, Larsen P D
Section of Anaesthesia, Wellington School of Medicine,
New Zealand.
In this study we sought to develop quantitative methods
for determining the presence of cardioventilatory coupling
in raw heart rate time series. The beat-to-beat RR interval
time series of 98 anaesthetized, spontaneously breathing
subjects were represented graphically as (1) raw RR interval
time series, (2) RR consecutive difference time series and
(3) a phase portrait of the RR consecutive difference time
series. We then examined the relationships between the presence
of cardioventilatory coupling in these epochs and the plot
appearance and entropy measures derived from these plots.
We observed that coupling was significantly associated with
the presence of banding in the raw heart rate and RR consecutive
difference time series, and with discrete clustering within
the RR consecutive difference phase portrait. A significant
correlation was found between coupling and the entropy of
the RR consecutive difference time series and its phase
portrait. We conclude that, with some provisos, these simple
graphical and derived quantitative measures provide a basis
for the determination of cardioventilatory coupling from
heart rate time series.
PMID: 11878682, UI: 21867470
Br J Anaesth 2001 Dec;87(6):819-26
Cardioventilatory coupling in heart rate variability:
the value of standard analytical techniques.
Larsen P D, Galletly D C
Section of Anaesthesia, Wellington School of Medicine,
New Zealand.
In a group of spontaneously breathing anaesthetized subjects,
we examined the ability of simple spectral and non-linear
methods to detect the presence of cardioventilatory coupling
in heart rate time series. Using the proportional Shannon
entropy (H(RI-1)) of the RI(-1) interval (interval between
inspiration and the preceding ECG R wave) as a measure of
coupling, we found no correlation between H(RI-1) and either
the fractal dimension or approximate entropy of the heart
rate time series. We also observed no difference in the
distribution of heart rate variability (HRV) spectral power
in three frequency ranges (high, 0.15-0.45 Hz; low, 0.08-0.15
Hz; very low, 0.02-0.08 Hz) between uncoupled epochs and
coupling patterns I, III and IV. Because of its association
with low breathing frequencies, pattern II coupling epochs
showed exaggerated low-frequency power as the high-frequency
'respiratory' peak fell into the low-frequency range. We
conclude that coupling pattern is largely independent of
autonomic tone and that these standard methods of HRV analysis
are limited in their ability to detect the presence of cardioventilatory
coupling in heart rate time series.
PMID: 11878681, UI: 21867469
Br J Anaesth 2002 Feb;88(2):301-2; discussion
302
Do ex-premature infants need mechanical ventilation for
inguinal hernia repair?
Bouchut JC, Claris O
Publication Types:
Letter
PMID: 11878667, UI: 21867454
Br J Anaesth 2002 Feb;88(2):270-6
Analgesia for pelvic brachytherapy.
Smith MD, Todd JG, Symonds RP
Royal Alexandra Hospital, Paisley, UK.
Pelvic brachytherapy presents the anaesthetist with numerous
challenges. Patients vary from highly distressed young adults,
to the elderly with coincidental disease severe enough to
preclude surgery. The painful radioactive implants remain
in place for a number of days. Treatment in isolated rooms
reduces radiation exposure to staff, but makes close postoperative
monitoring difficult, so the analgesic technique should
involve minimum risk to the patient. Although there is very
little published evidence of specific analgesic techniques
in this area, knowledge of these problems allows the anaesthetist
to select appropriate systemic analgesics and regional blocks
to provide safe and effective pain relief.
Publication Types:
Review
Review, tutorial
PMID: 11878659, UI: 21867444
J Cardiothorac Vasc Anesth 2002 Apr;16(2):240-5
Case 2-2002 thoracic epidural anesthesia in patients with
ankylosing spondylitis undergoing coronary artery surgery.
Varadarajan B, Whitaker DK, Vohra A, Smith MS
Department of Anaesthesia, Manchester Royal Infirmary,
Manchester, United Kingdom.
[Medline record in process]
PMID: 11957178, UI: 21953103
J Cardiothorac Vasc Anesth 2002 Apr;16(2):157-162
Alfentanil and sufentanil in fast-track anesthesia for
coronary artery bypass graft surgery.
Tritapepe L, Voci P, Di Giovanni C, Pizzuto F, Cuscianna
E, Caretta Q, Pietropaoli P
Departments of Anesthesia and Intensive Care and Cardiac
Surgery, University of Rome "La Sapienza," Rome,
Italy.
[Record supplied by publisher]
OBJECTIVE: To evaluate alfentanil, sufentanil, and the
combination of both opioids in patients undergoing cardiac
surgery. DESIGN: Prospective, randomized study. SETTING:
University hospital. PARTICIPANTS: Patients undergoing coronary
artery bypass graft (CABG) surgery (n = 195), randomly assigned
to 3 groups of 65 each. INTERVENTIONS: Patients in group
A received alfentanil, induction (15 &mgr;g/kg) and maintenance
(15 &mgr;g/kg/hr); patients in group S received sufentanil,
induction (1 &mgr;g/kg) and maintenance (1 &mgr;g/kg/h);
and patients in group AS received alfentanil and sufentanil,
induction with alfentanil (15 &mgr;g/kg) and maintenance
with sufentanil (1 &mgr;g/kg/hr). Measurements and Main
Results: Hemodynamic data showed a reduction of all parameters
at induction in the 3 groups (p < 0.05). Cardiac index
decreased at induction in all groups (p < 0.05) but increased
in groups S and AS toward baseline values at the end of
surgery. The intubation time and length of stay in the intensive
care unit were less in group AS (2.3 +/- 1.2 hours; p <
0.001 and 20 +/- 8 hours; p < 0.05), than in groups A
(4.2 +/- 1.7 hours and 28 +/- 13 hours) and S (3.1 +/- 1.1
hours; p < 0.05 and 26 +/- 12 hours). Length of hospital
stay and patients' outcome were similar in the 3 groups.
CONCLUSION: Although the differences among groups regarding
extubation time, intensive care unit length of stay, and
some hemodynamic data were statistically significant, the
differences were clinically small. All 3 anesthetic protocols
were shown to be safe and appropriate for patients undergoing
elective coronary artery bypass graft surgery and early
postoperative tracheal extubation. Copyright 2002, Elsevier
Science (USA). All rights reserved.
PMID: 11957163
JAMA 2002 Mar 27;287(12):1577
A 58-year-old woman dissatisfied with her care, 2 years
later.
Audet AM, Hartman EE
The Commonwealth Fund, New York, NY, USA.
Publication Types:
Clinical conference
PMID: 11911761, UI: 21909862
Lancet 2002 Apr 13;359(9314):1276-82
Epidural anaesthesia and analgesia and outcome of major
surgery: a randomised trial.
Department of Public Health, University of Western Australia,
Western, Crawley, Australia
[Medline record in process]
Background Epidural block is widely used to manage major
abdominal surgery and postoperative analgesia, but its risks
and benefits are uncertain. We compared adverse outcomes
in high-risk patients managed for major surgery with epidural
block or alternative analgesic regimens with general anaesthesia
in a multicentre randomised trial.Methods 915 patients undergoing
major abdominal surgery with one of nine defined comorbid
states to identify high-risk status were randomly assigned
intraoperative epidural anaesthesia and postoperative epidural
analgesia for 72 h with general anaesthesia (site of epidural
selected to provide optimum block) or control. The primary
endpoint was death at 30 days or major postsurgical morbidity.
Analysis by intention to treat involved 447 patients assigned
epidural and 441 control.Findings 255 patients (57 small
middle dot1%) in the epidural group and 268 (60 small middle
dot7%) in the control group had at least one morbidity endpoint
or died (p=0 small middle dot29). Mortality at 30 days was
low in both groups (epidural 23 [5 small middle dot1%],
control 19 [4 small middle dot3%], p=0 small middle dot67).
Only one of eight categories of morbid endpoints in individual
systems (respiratory failure) occurred less frequently in
patients managed with epidural techniques (23% vs 30%, p=0
small middle dot02). Postoperative epidural analgesia was
associated with lower pain scores during the first 3 postoperative
days. There were no major adverse consequences of epidural-catheter
insertion.Interpretation Most adverse morbid outcomes in
high-risk patients undergoing major abdominal surgery are
not reduced by use of combined epidural and general anaesthesia
and postoperative epidural analgesia. However, the improvement
in analgesia, reduction in respiratory failure, and the
low risk of serious adverse consequences suggest that many
high-risk patients undergoing major intra-abdominal surgery
will receive substantial benefit from combined general and
epidural anaesthesia intraoperatively with continuing postoperative
epidural analgesia.
PMID: 11965272, UI: 21962180
Lancet 2002 Apr 6;359(9313):1207-9
Comparison of upper airway collapse during general anaesthesia
and sleep.
Eastwood PR, Szollosi I, Platt PR, Hillman DR
Departments of Pulmonary Physiology, Sir Charles Gairdner
Hospital, Western Australia, Perth, Australia
[Medline record in process]
Measurement of the collapsibility of the upper airway while
a patient is awake is not a good guide to such collapsibility
during sleep, presumably because of differences in respiratory
drive, muscle tone, and sensitivity of reflexes. To assess
whether a relation existed between general anaesthesia and
sleep, we measured collapsibility of the upper airway during
general anaesthesia and severity of sleep-disordered breathing
in 25 people who were having minor surgery on their limbs.
Anaesthetised patients who needed positive pressure to maintain
airway patency had more severe sleep-disordered breathing
than did those whose airways remained patent at or below
atmospheric pressure. Such an association was strongest
during rapid-eye-movement (REM) sleep. Our findings suggest
that sleep-disordered breathing should be considered in
all patients with a pronounced tendency for upper airway
obstruction during anaesthesia or during recovery from it.
PMID: 11955541, UI: 21953599
Neurosci Lett 2002 Mar 1;320(1-2):49-52
Effects of electroacupuncture on the mechanical allodynia
in the rat model of neuropathic pain.
Hwang BG, Min BI, Kim JH, Na HS, Park DS
Department of East-West Medicine, Graduate School, Kyung
Hee University, Seoul, South Korea.
The analgesic effects of acupuncture on the mechanical
allodynia in the rat model of neuropathic pain have not
yet been studied. The aim of the present study is: first,
to determine if electroacupuncture (EA) or morphine attenuates
the mechanical allodynia; and secondly, to examine if the
EA effect may be mediated by endogenous opioids. To produce
neuropathic pain, the right superior caudal trunk was resected
between the S3 and S4 spinal nerves. Twenty-one days after
the neuropathic surgery, low frequency EA stimulation (2
Hz, 0.3 ms, 0.07 mA) delivered to Houxi (S13) for 30 min
relieved significantly the signs of mechanical allodynia.
Intraperitoneal (i.p.) morphine (0.5 or 1.5 mg/kg) also
relieved the signs of mechanical allodynia in a dose-dependent
manner. In addition, the antiallodynic effect of Houxi EA
was blocked by pretreatment with naloxone (2 mg/kg, i.p.).
However, combined application of EA and morphine did not
show an obvious synergistic effect. These results suggest
that low frequency EA or morphine can relieve the mechanical
allodynia signs and the EA effect can be mediated by endogenous
opioid systems.
PMID: 11849761, UI: 21839758
Neurosci Lett 2002 Mar 1;320(1-2):21-4
Unique immunomodulation by electro-acupuncture in humans
possibly via stimulation of the autonomic nervous system.
Mori H, Nishijo K, Kawamura H, Abo T
Department of Acupuncture, Tsukuba College of Technology,
Tsukuba 305-0821, Japan.
Cumulative evidence suggests that immunologic responses
are under the regulation of the autonomic nervous system.
Since acupuncture has recently been reported to modulate
the autonomic nervous system, we investigated the possibility
that acupuncture eventually modulates the immune system.
In the present study, electro-acupuncture was applied in
young volunteer subjects. As for the proportions of granulocytes
and lymphocytes in the blood, there were three groups: (1)
granulocytosis and lymphocytopenia; (2) granulocytopenia
and lymphocytosis; and (3) normal pattern. Interestingly,
with the administration of acupuncture, the status of subjects
with relatively low levels of granulocytes and high levels
of lymphocytes shifted to Group 1, whereas that of subjects
with high levels of granulocytes and low levels of lymphocytes
shifted to Group 2. In other words, acupuncture tended to
normalize the pattern of leukocytes. We confirmed that acupuncture
induced parasympathetic nerve stimulation, resulting in
a decrease in the heart rate. These results suggest possible
mechanisms underlying how acupuncture ameliorates the condition
of patients with many chronic diseases.
PMID: 11849754, UI: 21839751
Reg Anesth Pain Med 2002 Mar-Apr;27(2):227-8;
discussion 228
How close is close enough--how close is safe enough.
Kaiser H, Neuburger M
PMID: 11915079, UI: 21912608
Reg Anesth Pain Med 2002 Mar-Apr;27(2):226-7;
discussion 227
Combined lumbar and sacral plexus block for the management
of long-standing hip pain.
De Cordoba JL, Marqueta CG, Bernal J, Asuncion J
Publication Types:
Letter
PMID: 11915077, UI: 21912606
Reg Anesth Pain Med 2002 Mar-Apr;27(2):207-10
Estimating with confidence the risk of rare adverse events,
including those with observed rates of zero.
Ho AM, Dion PW, Karmakar MK, Lee A
Department of Anaesthesia and Intensive Care, The Chinese
University of Hong Kong, Shatin, NT, Hong Kong SAR, People's
Republic of China. hoamh@hotmail.com
Omission of a confidence interval (CI) associated with
the risk of a serious complication can lead to inaccurate
interpretation of risk data. The calculation of a CI for
a risk or a single proportion typically uses the familiar
Gaussian (normal) approximation. However, when the risk
is small, "exact" methods or other special techniques
should be used to avoid overshooting (risks that include
values outside of [0,1]) and zero width interval degeneration.
Computer programs and simple equations are available to
construct CIs reasonably accurately. In the special case
in which the complication has not occurred, the risk estimated
with 95% confidence is no worse than 3/n, where n is the
number of trials.
PMID: 11915070, UI: 21912599
Reg Anesth Pain Med 2002 Mar-Apr;27(2):200-6
Ultrasound imaging of the thoracic epidural space.
Grau T, Leipold RW, Delorme S, Martin E, Motsch J
Department of Anesthesiology, University Clinic of Heidelberg,
Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany. grau-heidelberg@web.de
BACKGROUND AND OBJECTIVES: In thoracic epidural anesthesia,
the "loss of resistance" technique is the standard
technique for the identification of the epidural space (EDS),
the feedback to the operator is often solely tactile. Our
aim was to establish ultrasonography for the prepuncture
demonstration of the anatomic structures surrounding the
thoracic EDS and to evaluate its precision and imaging quality.
METHODS: We examined 20 volunteers. In each participant,
the extradural space and the neighboring anatomic landmarks
in the intervertebral space Th 5-6 were identified using
2 imaging techniques: magnetic resonance imaging (MRI) and
ultrasonography. We compared corresponding images regarding
distance measurements and the visibility of anatomic landmarks.
RESULTS: The capacity of ultrasound imaging (US) to depict
the thoracic EDS was limited. Due to the better overview,
MR images were easier to interpret. However, US proved to
be of better value than MRI in the depiction of the dura
mater. All important landmarks for the puncture of the thoracic
EDS could be identified with both techniques. The overall
correlation was satisfactory. US depicted the different
structures of the thoracic EDS with an acceptable precision
(confidence interval, 4.6 to 8.7 mm). CONCLUSIONS: US showed
good correlation with MRI, which is a standard imaging technique
for the depiction of the spine. We anticipate that prepuncture
ultrasonography may facilitate thoracic epidural anesthesia
by needle placement.
PMID: 11915069, UI: 21912598
Reg Anesth Pain Med 2002 Mar-Apr;27(2):168-72
Continuous subgluteus sciatic nerve block after orthopedic
foot and ankle surgery: comparison of two infusion techniques.
di Benedetto P, Casati A, Bertini L
Department of Anesthesiology, CTO Roma, Rome, Italy.
BACKGROUND AND OBJECTIVE: To compare continuous infusion
or a patient-controlled technique for postoperative analgesia
after foot surgery, using a new subgluteus approach for
continuous sciatic nerve block. METHODS: Fifty healthy patients,
undergoing orthopedic foot surgery, received a continuous
sciatic nerve block using a new subgluteus approach. All
blocks were placed with the aid of a nerve stimulator using
a 10-cm, 18-gauge insulated Tuohy needle. After either plantar
flexion or dorsiflexion of the operated foot was elicited
at < or = 0.5 mA, 20 mL of 0.75% ropivacaine was injected
incrementally using repeated aspiration tests, then followed
by the introduction of a 20-gauge epidural catheter. Postoperatively,
0.2% ropivacaine was infused with either a 10 mL/h continuous
infusion (group Continuous, n = 25) or with a 5 mL/h basal
rate with 5 mL bolus every 60 minutes (group patient-controlled
analgesia [PCA], n = 25). Intraoperative analgesic supplementation,
as well as postoperative pain relief, morphine consumption,
incidence of complication, and patient satisfaction were
recorded by an observer unaware of group assignment. RESULTS:
The sciatic catheter was successfully placed in all patients.
Intravenous fentanyl supplementation (dose range, 50 to
150 microg) was required in 4 patients in each group, but
no patient required general anesthesia. Catheter dislocation
was reported in 2 patients (4%). The quality of pain relief
was good in both groups, and none experienced complications.
Nine patients of the Continuous group (37%) and 7 patients
of the PCA group (29%) required rescue morphine analgesia
because of pain in the femoral dermatomes (P =.76). Ropivacaine
consumption was 240 mL in the Continuous group (range, 200
to 240 mL) and 140 mL in the PCA group (range, 120 to 290
mL) (P =.0005). Patient acceptance was good in both groups.
CONCLUSIONS: The continuous subgluteus sciatic nerve block
represents an easy and reliable option for postoperative
analgesia after foot surgery; using a patient controlled
rather than a continuous infusion technique reduces the
consumption of local anesthetic solution without affecting
the quality of pain relief.
Publication Types:
Clinical trial
Randomized controlled trial
PMID: 11915064, UI: 21912593
Reg Anesth Pain Med 2002 Mar-Apr;27(2):139-44
The effect of single-injection femoral nerve block on
rehabilitation and length of hospital stay after total knee
replacement.
Wang H, Boctor B, Verner J
Department of Anesthesiology, Henry Ford Hospital, 2799
W. Grand Boulevard, Detroit, MI 48202, USA. hwang2@hfhs.org
BACKGROUND AND OBJECTIVES: Continuous-infusion femoral
nerve block (FNB) improves analgesia and rehabilitation
after total knee replacement. In this study, we investigated
the efficacy of single-injection FNB to achieve similar
results. METHODS: A total of 30 patients were prospectively
and randomly assigned to receive 40-mL injections of either
0.25% bupivacaine (group B) or saline (group S) after total
knee replacement. Blinded observers evaluated the patients
for postoperative pain, morphine consumption, ambulating
distances, and maximal knee flexion; pain was scored on
the visual analog scale (VAS). RESULTS: Compared with group
S patients, group B patients had significantly lower VAS
pain scores (P <.01 in the postoperative anesthesia care
unit, P <.05 on the day after surgery); group B patients
also showed significantly lower total morphine use (P <.05)
and a lower incidence of morphine-related side effects.
Significantly more group B than group S patients could ambulate
on the day after surgery (93% v 46%, P <.05), and mean
ambulatory distance was significantly better for group B
than group S patients at discharge (166 +/- 37 v 117 +/-
24 feet, P <.01). Knee flexion was significantly better
for group B than group S patients on the second day after
surgery (70 degrees v 60 degrees, P <.01), but the between-group
difference was no longer statistically significant at discharge.
Mean length of acute hospitalization was significantly shorter
for group B (3 days; range, 3 to 5 days) than group S patients
(4 days; range, 3 to 6 days, P <.05). CONCLUSIONS: Single-injection
FNB provided effective analgesia, facilitated early ambulation,
and reduced the length of acute hospitalization in patients
undergoing total knee replacement.
TUTTO
IL MATERIALE CONTENUTO IN QUESTO SITO E' STATO REPERITO IN RETE. GLI AUTORI
NON SI ASSUMONO RESPONSABILITA' PER
DANNI A TERZI DERIVATI DA USO IMPROPRIO O ILLEGALE DELLE INFORMAZIONI
RIPORTATE O DA ERRORI RELATIVI AL LORO CONTENUTO.
