Ultimo Aggiornamento: Agosto 2001

Anesthesiology 2001 Jun;94(6):999-1006

Recovery of intraoperative microbicidal and inflammatory functions of alveolar immune cells after a tobacco smoke-free period.

Kotani N, Kushikata T, Hashimoto H, Sessler DI, Muraoka M, Matsuki A

Department of Anesthesiology, University of Hirosaki, Japan. nao@cc.hirosaki-u.ac.jp

BACKGROUND: Tobacco smoking inhibits alveolar macrophage function, but cessation of smoking markedly reduces the risk of postoperative pulmonary complications. The authors therefore evaluated the effect of nonsmoking duration on both antimicrobial and inflammatory functions of alveolar macrophages during anesthesia and surgery. METHODS: The authors studied 15 patients who had never smoked, 15 current smokers, and 41 former smokers, all of whom underwent general anesthesia. Former smokers were further allocated to one of three groups depending on their smoke-free periods: 2 months (n = 13), 3-5 months (n = 13), and 6-12 months (n = 15). Alveolar immune cells were collected by bronchoalveolar lavage immediately after induction of anesthesia, at 2 and 4 h after induction of anesthesia, and at the end of surgery. Opsonized and nonopsonized phagocytosis were measured. Microbicidal activity was determined as the ability of the macrophages to kill Listeria monocytogenes directly. Finally, we determined the expression of proinflammatory cytokines, including interleukin 1beta, interleukin 8, interferon gamma, and tumor necrosis factor alpha, and of antiinflammatory cytokines (interleukin 4 and 10) by semiquantitative polymerase chain reaction. RESULTS: Nonopsonized and opsonized phagocytosis and microbicidal activity of alveolar macrophages (antimicrobial functions) decreased 20-50%, and the expression of genes for all proinflammatory and antiinflammatory cytokines increased 3-30-fold over time in all groups. Starting 4 h after induction of anesthesia, the decreases in antimicrobial functions were 1.5-3 times greater in current and former smokers (2 months' abstinence) than in patients who had never smoked. Starting 4 h after anesthesia, the increase in expression of all cytokines, except interleukin 8, was twofold to fivefold less in current and former smokers (2-6 months' abstinence) than in patients who had never smoked. CONCLUSION: Our data suggest that former smokers may have a limited ability to mount effective pulmonary immune defenses for long as 6 months after stopping cigarette use.

Publication Types:

Clinical trial

PMID: 11465626, UI: 21358151

Anesthesiology 2001 Jun;94(6):968-72

Comparison of the intubating laryngeal mask airway with the fiberoptic intubation in anticipated difficult airway management.

Langeron O, Semjen F, Bourgain JL, Marsac A, Cros AM

Departement d'Anesthesie-Reanimation, Centre Hospitalo-universitaire Pitie-Salpetriere, Assistance Publique-Hopitaux de Paris, Universite Pierre et Marie Curie, France. olivier.langeron@psl.ap-hop-paris.fr

BACKGROUND: The intubating laryngeal mask airway (ILMA; Fastrach; Laryngeal Mask Company, Henley-on-Thames, UK) may provide an alternative technique to fiberoptic intubation (FIB) to facilitate the management of the anticipated difficult airway. The authors therefore compared the effectiveness of the ILMA with FIB in patients with anticipated difficult intubation. METHODS: One hundred patients, with at least one difficult intubation criteria (Mallampati class III or IV, thyromental distance < 65 mm, interincisor distance < 35 mm) were enrolled (FIB group, n = 49; ILMA group, n = 51) in this prospective randomized study. Anesthesia was induced with propofol and maintained with alfentanil and propofol after an efficient mask ventilation has been demonstrated. The success of the technique (within three attempts), the number of attempts, duration of the successful attempt, and adverse events (oxygen saturation < 90%, bleeding) were recorded. RESULTS: The rate of successful tracheal intubation with ILMA was 94% and comparable with FIB (92%). The number of attempts and the time to succeed were not significantly different between groups. In case of failure of the first technique, the alternative technique always succeeded. Failures in FIB group were related to oxygen desaturation (oxygen saturation < 90%) and bleeding, and to previous cervical radiotherapy in the ILMA group. Adverse events occurred significantly more frequently in FIB group than in ILMA group (18 vs. 0%, P < 0.05). CONCLUSION: The authors obtained a high success rate and comparable duration of tracheal intubation with ILMA and FIB techniques. In patients with previous cervical radiotherapy, the use of ILMA cannot be recommended. Nevertheless, the use of the ILMA was associated with fewer adverse events.

Publication Types:

Clinical trial
Multicenter study
Randomized controlled trial

PMID: 11465622, UI: 21358147

Anesthesiology 2001 Jun;94(6):1150-1

CSE in labor and hypoglycemia.

Verma SR, Plaat F

Publication Types:

Letter

PMID: 11465614, UI: 21358175

Anesthesiology 2001 Jun;94(6):1148; discussion 1149

Phantom limb sensation: a need for more elaborated studies.

Gentili ME

Publication Types:

Letter

PMID: 11465612, UI: 21358173

Anesthesiology 2001 Jun;94(6):1066-73

Attenuation of the tumor-promoting effect of surgery by spinal blockade in rats.

Bar-Yosef S, Melamed R, Page GG, Shakhar G, Shakhar K, Ben-Eliyahu S

Department of Anesthesiology, Rabin Medical Center, Petach Tikva, Israel.

BACKGROUND: The perioperative period is characterized by a state of immunosuppression, which was shown in animal studies to underlie the promotion of tumor metastasis by surgery. As this immunosuppression is partly ascribed to the neuroendocrine stress response, the authors hypothesized that spinal blockade, known to attenuate this response, may reduce the tumor-promoting effect of surgery. METHODS: Fischer-344 rats were subjected to a laparotomy during general halothane anesthesia alone or combined with either systemic morphine (10 mg/kg) or spinal block using bupivacaine (50 microg) with morphine (10 microg). Control groups were either anesthetized or undisturbed. Blood was drawn 5 h after surgery to assess number and activity of natural killer cells, or rats were inoculated intravenously with MADB106 adenocarcinoma cells, which metastasize only to the lungs. Metastatic development was assessed by quantifying lung retention of tumor cells 24 h after inoculation or by counting pulmonary metastases 3 weeks later. RESULTS: Laparotomy conducted during general anesthesia alone increased lung tumor retention up to 17-fold. The addition of spinal block reduced this effect by 70%. The number of metastases increased from 16.7 +/- 10.5 (mean +/- SD) in the control group to 37.2 +/- 24.4 after surgery and was reduced to 10.5 +/- 4.7 during spinal block. Systemic morphine also reduced the effects of surgery, but to a lesser degree. Natural killer cell activity was suppressed to a similar extent by surgery and by anesthesia alone. CONCLUSIONS: The addition of spinal blockade to general halothane anesthesia markedly attenuates the promotion of metastasis by surgery.

PMID: 11465599, UI: 21358160

Anesthesiology 2001 Jun;94(6):1007-9

Lack of degradation of sevoflurane by a new carbon dioxide absorbent in humans.

Mchaourab A, Arain SR, Ebert TJ

Department of Anesthesiology, Medical College of Wisconsin and VA Medical Center, Milwaukee, USA.

BACKGROUND: Potent inhaled anesthetics degrade in the presence of the strong bases (sodium hydroxide or potassium hydroxide) in carbon dioxide (CO2) absorbents. A new absorbent, Amsorb (Armstrong Medical Ltd., Coleraine, Northern Ireland), does not employ these strong bases. This study compared the scavenging efficacy and compound A production of two commercially available absorbents (soda lime and barium hydroxide lime) with Amsorb in humans undergoing general anesthesia. METHODS: Four healthy volunteers were anesthetized on different days with desflurane, sevoflurane, enflurane, and isoflurane. End-tidal carbon dioxide (ETCO2) and anesthetic concentrations were measured with infrared spectroscopy; blood pressure and arterial blood gases were obtained from a radial artery catheter. Each anesthetic exposure lasted 3 h, during which the three fresh (normally hydrated) CO2 absorbents were used for a period of 1 h each. Anesthesia was administered with a fresh gas flow rate of 2 l/min of air:oxygen (50:50). Tidal volume was 10 ml/kg; respiratory rate was 8 breaths/min. Arterial blood gases were obtained at baseline and after each hour. Inspired concentrations of compound A were measured after 15, 30, and 60 min of anesthetic administration for each CO2 absorbent. RESULTS: Arterial blood gases and ETCO2 were not different among three CO2 absorbents. During sevoflurane, compound A formed with barium hydroxide lime and soda lime, but not with Amsorb. CONCLUSIONS: This new CO2 absorbent effectively scavenged CO2 and was not associated with compound A production.

Publication Types:

Clinical trial

PMID: 11465591, UI: 21358152

Anesthesiology 2001 Jul;95(1):87-95

Pharmacokinetics of bupivacaine after continuous epidural infusion in infants with and without biliary atresia.

Meunier JF, Goujard E, Dubousset AM, Samii K, Mazoit JX

Laboratoire d'Anesthesie, UPRES EA392 Faculte de Medecine du Kremlin-Bicetre, Universite Paris-Sud, France.

BACKGROUND: Continuous epidural infusion of bupivacaine is widely practiced for postoperative pain relief in pediatric patients. However, bupivacaine may induce adverse effects in infants (convulsions or cardiac arrhythmias), likely because of decreased hepatic clearance and serum protein binding capacity. The authors wanted to examine the complex relations between age, alpha-1 acid glycoprotein (AAG) concentration, and unbound and total bupivacaine serum concentrations in infants receiving bupivacaine epidurally for 2 days. METHODS: Twenty-two infants aged 1-7 months (12 with biliary atresia and 10 with another disease) received a continuous epidural infusion of 0.375 mg x kg(-1) x h(-1) bupivacaine during 2 days (during and after surgery). Unbound and total bupivacaine concentration in serum was measured 0.5, 4, 24, and 48 h after infusion initiation. AAG concentration was measured in serum before and 2 days after surgery. In eight additional infants, the blood/plasma concentration ratio was measured in vitro at whole blood concentrations of 2 and 20 microg/ml. Bupivacaine concentration was fitted to a one-compartment model to calculate basic pharmacokinetic parameters. RESULTS: No adverse effects were observed. AAG increased markedly after surgery, and the increase was correlated to both age and preoperative AAG concentration. Two infants aged 1.8 months had unbound concentrations greater than 0.2 microg/ml. Clearance of unbound drug significantly increased with age. Because of increased drug binding, clearance of bound drug decreased both with time (from 0.5 to 48 h) and with age. Blood/plasma ratio was 0.77+/-0.08 and 0.85+/-0.24 at 2 and 20 microg/ml, respectively. CONCLUSIONS: Because of a low AAG concentration and a low intrinsic clearance, unbound bupivacaine increased to concentrations greater than 0.2 microg/ml in two infants younger than 2 months, after 2 days of infusion at a rate of 0.375 mg x kg(-1) x h(-1). The increase in AAG observed after surgery did not fully buffer this unbound fraction. Similarly, the buffer capacity of erythrocytes did not sufficiently increase at high concentration to compensate the saturation of the AAG system. Thus, we propose the use of a maximum dose of 0.25 mg x kg(-1) x h(-1) in infants younger than 4 months and a maximum of 0.3 mg x kg(-1) x h(-1) in infants older than 4 months.

PMID: 11465589, UI: 21358086

Anesthesiology 2001 Jul;95(1):6-17

Comparison of closed-loop controlled administration of propofol using Bispectral Index as the controlled variable versus "standard practice" controlled administration.

Struys MM, De Smet T, Versichelen LF, Van De Velde S, Van den Broecke R, Mortier EP

Department of Anesthesia, Ghent University Hospital, Belgium. Michel.Struys@rug.ac.be

BACKGROUND: This report describes a new closed-loop control system for propofol that uses the Bispectral Index (BIS) as the controlled variable in a patient-individualized, adaptive, model-based control system, and compares this system with manually controlled administration of propofol using hemodynamic and somatic changes to guide anesthesia. METHODS: Twenty female patients, American Society of Anesthesiologists physical status I or II, who were scheduled for gynecologic laparotomy were included to receive propofolremifentanil anesthesia. In group I, propofol was titrated using a BIS-guided, model-based, closed-loop system. The BIS target was set at 50. In group II, propofol was titrated using classical hemodynamic signs of (in)adequate anesthesia. Performance of control during induction and maintenance of anesthesia were compared between both groups using BIS as the controlled variable in group I and the reference variable in group II, and, conversely, the systolic blood pressure as the controlled variable in group II and the reference variable in group I. At the end of anesthesia, recovery profiles between groups were compared. RESULTS: Although patients undergoing manual induction of anesthesia in group II at 300 ml/h reached a BIS level of 50 faster than patients undergoing open-loop, computer-controlled induction in group I, manual induction caused a more pronounced initial overshoot of the BIS target. This resulted in a more pronounced decrease in blood pressure in group II. During the maintenance phase, better control of BIS and systolic blood pressure was found in group I compared with group II. Recovery was faster in group I. CONCLUSION: A closed-loop system for propofol administration using the BIS as a controlled variable together with a model-based controller is clinically acceptable during general anesthesia.

Publication Types:

Clinical trial
Evaluation studies

PMID: 11465585, UI: 21358075

Anesthesiology 2001 Jul;95(1):36-42

The validity of performance assessments using simulation.

Devitt JH, Kurrek MM, Cohen MM, Cleave-Hogg D

Department of Anaesthesia, University of Toronto, Sunnybrook and Women's College Health Sciences Centre, Ontario, Canada. exhd@qe2-hsc.ns.ca

BACKGROUND: The authors wished to determine whether a simulator-based evaluation technique assessing clinical performance could demonstrate construct validity and determine the subjects' perception of realism of the evaluation process. METHODS: Research ethics board approval and informed consent were obtained. Subjects were 33 university-based anesthesiologists, 46 community-based anesthesiologists, 23 final-year anesthesiology residents, and 37 final-year medical students. The simulation involved patient evaluation, induction, and maintenance of anesthesia. Each problem was scored as follows: no response to the problem, score = 0; compensating intervention, score = 1; and corrective treatment, score = 2. Examples of problems included atelectasis, coronary ischemia, and hypothermia. After the simulation, participants rated the realism of their experience on a 10-point visual analog scale (VAS). RESULTS: After testing for internal consistency, a seven-item scenario remained. The mean proportion scoring correct answers (out of 7) for each group was as follows: university-based anesthesiologists = 0.53, community-based anesthesiologists = 0.38, residents = 0.54, and medical students = 0.15. The overall group differences were significant (P < 0.0001). The overall realism VAS score was 7.8. There was no relation between the simulator score and the realism VAS (R = -0.07, P = 0.41). CONCLUSIONS: The simulation-based evaluation method was able to discriminate between practice categories, demonstrating construct validity. Subjects rated the realism of the test scenario highly, suggesting that familiarity or comfort with the simulation environment had little or no effect on performance.

Publication Types:

Evaluation studies

PMID: 11465581, UI: 21358079

BMJ 2001 Aug 11;323(7308):S2-S7308

"Time out" from anaesthesia: why, what, and when?

Rechner J, Streets C

Oxford.

[Medline record in process]

PMID: 11498501, UI: 21389080

Can J Anaesth 2001 Jul;48(7):713-4

Wrist actigraphy in anesthesia.

Weinbroom AA, Ben-Abraham R, Zomer J

Tel Aviv, Israel.

[Medline record in process]

PMID: 11495884, UI: 21387165

Can J Anaesth 2001 Jul;48(7):681-3

Combined spinal-epidural anesthesia for Cesarean section in a patient with peripartum dilated cardiomyopathy :.

Shnaider R, Ezri T, Szmuk P, Larson S, Warters RD, Katz J

Department of Anesthesiology University of Texas Medical School at Houston, Houston, Texas, USA.

[Medline record in process]

PURPOSE: To report a case of peripartum dilated cardiomyopathy associated with morbid obesity and possible difficult airway presenting for elective Cesarean section, which was successfully managed with combined spinal-epidural anesthesia. Clinical features: A morbidly obese parturient with a potentially difficult airway, suffering from idiopathic peripartum cardiomyopathy (ejection fraction 20%), was scheduled for an elective Cesarean section. A combined spinal epidural anesthesia was performed and 6 mg of bupivacaine were injected into the subarachnoid space. This was supplemented after 60 min with 25 mg of bupivacaine injected epidurally. The patient's hemodynamic status was monitored with direct intra-arterial blood pressure and central venous pressure measurements. The patient's perioperative course was uneventful. CONCLUSION: In patients suffering from peripartum cardiomyopathy, undergoing Cesarean section, combined spinal-epidural anesthesia may be an acceptable anesthetic alternative.

PMID: 11495876, UI: 21387157

Can J Anaesth 2001 Jul;48(7):661-4

Preoperative diclofenac is a useful adjunct to spinal anesthesia for day-case varicose vein repair :.

Rautoma P, Santanen U, Luurila H, Perhoniemi V, Erkola O

Department of Anesthesia and Intensive Care Medicine, Helsinki University Hospital, Helsinki, Finland.

[Medline record in process]

PURPOSE: To examine if preoperative diclofenac 50 mg or diazepam 10 mg po are useful adjuncts to spinal anesthesia for day-case varicose vein repair. METHODS: Two hundred ASA physical status I-II outpatients, age 18-60 yr, were randomized to receive either diclofenac 50 mg po or diazepam 10 mg po one hour before operation in a double-blind fashion (100 patients in both groups). If the patient was distressed or feared the spinal puncture and requested sedation, a bolus dose of alfentanil 0.5 mg was given iv as a rescue medication. On request, patients received diclofenac 50 mg po and, when needed, oxycodone 0.1 mg*kg(-1) im for postoperative pain relief. They were discharged with a supply of diclofenac 50 mg tablets and were asked to record postoperative pain using a visual analogue scale (VAS) and quantity of tablets taken. RESULTS: The VAS scores (+/- SD) eight hours after surgery, the next morning, and in the morning and at the end of the first and second postoperative days were 23 +/- 21, 12 +/- 17, 11 +/- 15, 8 +/- 15 and 8 +/- 15 in the diclofenac group, and 24 +/- 23, 12 +/- 20, 10 +/- 17, 8 +/- 16 and 7 +/- 14 in the diazepam group, respectively (NS). In the diclofenac and diazepam groups, 31% and 67% of the patients required postoperative diclofenac during the first eight postoperative hours (P <0.05). Diazepam premedication did not alter the number of patients who required alfentanil before spinal puncture. CONCLUSION: Diclofenac premedication reduced the analgesic requirements during the first eight hours after varicose vein repair.

PMID: 11495873, UI: 21387154

Can J Anaesth 2001 Jul;48(7):656-60

Blocks at the wrist provide effective anesthesia for carpal tunnel release :.

Delaunay L, Chelly JE

Departement d'anesthesiologie, Clinique Generale, Annecy, France, and the. Department of Anesthesiology, The University of Texas Houston Health Science Center, Houston, Texas, USA.

[Medline record in process]

PURPOSE: Distal blocks are not recommended even for a short procedure when a tourniquet is used. This study was designed to evaluate the tolerance, effectiveness, patient acceptance and safety of distal blocks at the wrist. METHODS: Consecutive patients (n=273, mean age 53 +/-15 yr) undergoing endoscopic carpal tunnel release with a pneumatic tourniquet were included in this study. The median nerve was blocked 6 cm above the wrist crease by injecting 10 mL of 2% lidocaine and 0.5% bupivacaine (v/v). The ulnar nerve was blocked by injecting 8 mL of the same anesthetic mixture below the flexor carpi ulnaris tendon 6 cm above the wrist crease. Finally, 2 mL of local anesthetic were infiltrated sc and laterally below the crease to block the musculocutaneous nerve. The intensity of the block was evaluated after five, ten and 20 min. In addition, pain associated with block performance and tolerance of the tourniquet were evaluated. Finally, neurological complications associated with this technique were investigated. Data are presented as means +/- SD. RESULTS: At ten minutes after the block was performed, 9% and 32% of patients required an additional injection to complete the block in the median and ulnar territories, respectively. In more than 75% of patients, performance of the block was associated with either no or mild pain. The tourniquet was inflated for 12.6 +/- 5.4 min and was well tolerated in 99% of patients. Finally, neither transient nor permanent neurological deficit were recorded postoperatively. CONCLUSION: Blocks at the wrist are effective, well accepted by the patient and safe when a pneumatic tourniquet is used for a short procedure.

PMID: 11495872, UI: 21387153

Can J Anaesth 2001 Jul;48(7):637-45

A survey of professional satisfaction among Canadian anesthesiologists :.

Jenkins K, Wong D

Department of Anesthesia, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.

[Medline record in process]

PURPOSE: To assess overall job satisfaction among Canadian anesthesiologists and examine contributing factors. METHODS: A confidential postal survey of all active members of the Canadian Anesthesiologists Society was conducted in 1998. Demographics, anesthesia practice, overall job satisfaction, anesthetic assistance, and perceived surgeons' and public attitudes towards anesthesiologists were collected. RESULTS: Of 1659 surveys sent, 946 were returned (57% response rate). Seventy-five percent of the respondents were male and 25% female. Staff comprized 91%, residents 9%. The average working week was 59 +/- 11.9 hr. Seventy-five percent of respondents reported overall job satisfaction. Job satisfaction was associated with intellectual stimulation, good quality of care and interaction with patients. Dissatisfaction stemmed from treatment from the provincial government, hospital politics and long hours. Job satisfaction was associated with satisfaction with the level of operating room (OR) assistance, perceived high surgical regard and public image. Residents were more satisfied than staff anesthesiologists. Overall satisfaction was not affected by age, gender, region of practice, type of hospital or clinical work. CONCLUSIONS: Job satisfaction among anesthesiologists is significantly associated with intellectual stimulation, quality of care, interaction with the patients, treatment from the provincial government, hospital politics, working hours, OR assistance and perceived attitude of surgeons. Improving these contributing factors may lead to higher job satisfaction.

PMID: 11495869, UI: 21387150

Can J Anaesth 2001 Jul;48(7):622-5

Fast-tracking in ambulatory anesthesia / Le protocole accelere en anesthesie ambulatoire.

Song D, Chung F

Department of Anesthesia, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.

[Medline record in process]

PMID: 11495866, UI: 21387147

Obstet Gynecol 2001 May;97(5):suppl 1-3

ACOG Committee Opinion. Committee on Obstetric Practice. Optimal goals for anesthesia care in obstetrics.

[Medline record in process]

PMID: 11501566, UI: 21392466