Ultimo Aggiornamento: Agosto 2001

Anaesth Intensive Care 2001 Aug;29(4):417-20

General anaesthesia in a patient with undiagnosed "saber-sheath" trachea.

Garstang JS, Bailey DM

Department of Anaesthesia, The Ipswich Hospital, NHS Trust, Suffolk, United Kingdom.

[Medline record in process]

Saber-sheath trachea describes an abnormality in the shape of the trachea caused by underlying disease processes. We present a case of tracheal stenosis in a patient with undiagnosed saber-sheath trachea, in which there was unexpected difficulty in ventilating the lungs despite a good view at laryngoscopy and visually confirmed tracheal intubation.

PMID: 11512654, UI: 21403558

Anaesth Intensive Care 2001 Aug;29(4):406-16

Anaesthetic considerations for patients undergoing hypothermic cardiopulmonary bypass for complex neurovascular lesions: case presentation and review.

Burgess N, Isert P

Department of Anaesthesia and Intensive Care, Prince of Wales Hospital, Sydney, New South Wales.

[Medline record in process]

The anaesthetic management of a 38-year-old woman having excision of a meningioma involving the superior sagittal sinus is described. The procedure was performed using low flow moderate hypothermic cardiopulmonary bypass with central cannulation. Relevant literature is reviewed.

PMID: 11512653, UI: 21403557

Anaesth Intensive Care 2001 Aug;29(4):377-82

Intrathecal anaesthesia for the elderly patient: the influence of the induction position on perioperative haemodynamic stability and patient comfort.

Fredman B, Zohar E, Rislick U, Sheffer O, Jedeikin R

Department of Anesthesiology and Critical Care, Meir Hospital, Kfar Sava, Israel.

[Medline record in process]

Ninety elderly (>65 y) patients were studied to assess the influence of patient position during induction of spinal anaesthesia on the incidence of perioperative hypotension and haemodynamic stability. Prior to induction of anaesthesia, Lactated Ringer's solution (8-10 ml/kg) was administered. In the Sitting Group, intrathecal anaesthesia was performed with the patient in the sitting position. In the Lateral Group, patients assumed the lateral decubitus position. In all cases hyperbaric bupivacaine (10 mg) was administered using a 25 gauge Quincke spinal needle. Patients were placed in the supine (and thereafter lithotomy) position immediately after withdrawing the spinal needle. Incremental doses of ephedrine (5 mg, i.v.) were administered in response to hypotension (>20% of baseline), nausea, vomiting, sweating, skin pallor or impaired consciousness. The mean arterial blood pressure, heart rate and the number of hypotensive episodes requiring ephedrine administration were unaffected by group affiliation. In the Sitting Group, nine patients received 24 doses of ephedrine 5 mg i.v. In the Lateral Group, 21 incremental doses of ephedrine were administered to nine patients. The incidence of nausea, vomiting, sweating and pallor were similar between the groups. Patient comfort was similar. In summary, the incidence of hypotension and hypotension-related adverse effects was similar when intrathecal anaesthesia was induced in the sitting or lateral position. Furthermore, subjective perception of the induction process or anaesthetic experience was not affected by patient position.

PMID: 11512648, UI: 21403552

Anaesth Intensive Care 2001 Aug;29(4):331-8

Do anaesthetists need to wear surgical masks in the operating theatre? A literature review with evidence-based recommendations.

Skinner MW, Sutton BA

Department of Anaesthesia, North West Regional Hospital, Burnie, Tasmania.

[Medline record in process]

Many operating theatre staff believe that the surgical face mask protects the healthcare worker from potentially hazardous biological infections. A questionnaire-based survey, undertaken by Leyland' in 1993 to assess attitudes to the use of masks, showed that 20% of surgeons discarded surgical masks for endoscopic work. Less than 50% did not wear the mask as recommended by the Medical Research Council. Equal numbers of surgeons wore the mask in the belief they were protecting themselves and the patient, with 20% of these admitting that tradition was the only reason for wearing them. Policies relating to the wearing of surgical masks by operating theatre staff are varied. This indicates some confusion about the role of the surgical mask in modern surgical and anaesthetic practice. This review was undertaken to collate current evidence and make recommendations based on this evidence.

PMID: 11512642, UI: 21403546

Anaesth Intensive Care 2001 Aug;29(4):323

The history of intravenous anaesthesia: the barbiturates. Part 3.

Ball C, Westhorpe R

[Medline record in process]

PMID: 11512641, UI: 21403545

Anesth Analg 2001 Aug;93(2):518

Myocardial ischemia in cataract surgery patients.

Dhingra N

Publication Types:

Letter

PMID: 11473894, UI: 21367425

Anesth Analg 2001 Aug;93(2):515-6

Excessive voltage output?

Gray AT

Publication Types:

Letter

PMID: 11473889, UI: 21367420

Anesth Analg 2001 Aug;93(2):477-81 , 4th contents page

A study of the paravertebral anatomy for ultrasound-guided posterior lumbar plexus block.

Kirchmair L, Entner T, Wissel J, Moriggl B, Kapral S, Mitterschiffthaler G

Institute of Anatomy and Histology, Leopold-Franzens University of Innsbruck, Muellerstrasse 59, A-6010 Innsbruck, Austria. lukas.kirchmair@tirol.com

IMPLICATIONS: We investigated the feasibility of posterior paravertebral sonography as a basis for ultrasound-guided posterior lumbar plexus blockades. Posterior paravertebral sonography proved to be a reliable as well as accurate imaging procedure for visualization of the lumbar paravertebral region except the lumbar plexus.

PMID: 11473883, UI: 21367414

Anesth Analg 2001 Aug;93(2):447-55 , 4th contents page

The pharmacokinetics and pharmacodynamics of bupivacaine-loaded microspheres on a brachial plexus block model in sheep.

Estebe JP, Le Corre P, Du Plessis L, Chevanne F, Cathelineau G, Le Verge R, Ecoffey C

Service d'Anesthesie Reanimation Chirurgicale 2, Hopital Hotel Dieu, 2 rue de l'Hotel Dieu, 35000 Rennes, France. jean-pierre.estebe@chu-rennes.fr

We evaluated bupivacaine-loaded microspheres (B-Ms) using a brachial plexus block model in sheep. In the first step, pharmacokinetic characterization of 75 mg bupivacaine hydrochloride (B-HCl) (IV infusion and brachial plexus block) was performed (n = 12). In the second step, a brachial plexus block dose response study of B-HCl was performed with 37.5 mg, 75 mg, 150 mg, 300 mg, and 750 mg. As a comparison, evaluations were performed using a 750-mg bupivacaine base (B). In the third step, evaluations of brachial plexus block were performed with B-Ms (750 mg of B as B-Ms) using two formulations, 60/40 and 50/50 (w/w %); drug-free microspheres were also evaluated. Toxicity evaluations were also performed after IV administration of B-HCl (750 mg and 300 mg), B-Ms (750 mg), and drug-free microspheres (30 mL over 1 min). As the B-HCl dose increased, the time of onset of block decreased and the duration of complete motor blockade increased at the expense of an increase in bupivacaine plasma concentrations. The time of maximum concentration appeared to be independent of the B-HCl dose. In brachial plexus block, a 37.5-mg dose of B-HCl did not induce motor blockade whereas a dose of 750 mg of B-HCl was clinically toxic. In the case of IV administration, doses of 300 mg of B-HCl were as toxic as 750 mg of B-HCl. Compared with the 75 mg of B-HCl administration for brachial plexus block, administration of 750 mg of B as B-Ms increased the duration of complete motor blockade without significant difference in maximum concentration. No significant clinical difference between the two formulations of B-Ms was demonstrated. The IV administration of B-Ms was safe. We conclude that the controlled release of bupivacaine from microspheres prolonged the brachial plexus block without obvious toxicity. IMPLICATIONS: Administration of 750 mg of bupivacaine as loaded-microspheres resulted in prolongation of brachial plexus block in sheep. The peak plasma concentration was not significantly larger than that obtained with 75 mg of plain bupivacaine. The motor blockade was increased more than six times compared with 75 mg plain bupivacaine.

PMID: 11473878, UI: 21367409

Anesth Analg 2001 Aug;93(2):436-41 , 4th contents page

An evaluation of the infraclavicular block via a modified approach of the Raj technique.

Borgeat A, Ekatodramis G, Dumont C

Department of Anesthesiology, University Hospital of Zurich/Balgrist, Forchstrasse 340, CH-8008 Zurich, Switzerland. aborgeat@balgrist.unizh.ch

Infraclavicular plexus block has recently become a technique of increasing interest. However, no approach has provided easily identifiable landmarks, good conditions for catheter placement, and lack of complications (mainly pneumothorax). We describe a modified approach of the Raj technique based on the identification of the anterior acromial process, jugular notch, and emergence of the axillary artery within the axillary fossa, with the arm abducted to 90 degrees and elevated by approximately 30 degrees. We evaluated the clinical characteristics of this approach by injecting 40 to 50 mL of ropivacaine 0.6% in 150 patients scheduled for elective surgery of the forearm, wrist, or hand. Success was defined as a sensory block of the 5 nerves with territories distal to the elbow within 30 min after performing the block. The success rate was 97% when a distal response (flexion or extension of the wrist or fingers) was elicited and 44% when a proximal (contraction of the triceps, biceps) was obtained using a nerve stimulator. Complications were rare: aspiration of blood was seen in 2% of patients and hematoma was seen at the puncture site in 0.6%; no pneumothorax occurred. Eleven patients (7%) complained of some pain during the procedure. We conclude that the modified approach of the Raj technique for infraclavicular block is very effective when a distal nerve stimulator response is obtained with a small complication rate and a high degree of patient satisfaction. IMPLICATIONS: We describe a modified approach of the Raj technique for the infraclavicular brachial plexus. The elicitation of a distal nerve stimulator response is associated with a high success rate, a low incidence of complications and a high degree of patient satisfaction.

PMID: 11473876, UI: 21367407

Anesth Analg 2001 Aug;93(2):339-44 , 3rd contents page

The pharmacoeconomics of neuromuscular blocking drugs: a perioperative cost-minimization strategy in children.

Splinter WM, Isaac LA

Department of Anaesthesia, Children's Hospital of Eastern Ontario, 401 Smyth Road, Ottawa, Ontario, Canada K1H 8L1. splinter@cheo.on.ca

The purpose of this investigation was to compare the costs of intermediate-acting neuromuscular blocking drugs in children during routine ambulatory surgery. We studied 200 healthy, 2-10-yr-old children undergoing elective dental restorative surgery. During Part 1 of the study, children received an inhaled anesthetic with halothane and nitrous oxide, whereas in Part 2, the anesthetic was IV propofol with nitrous oxide. The study drugs were atracurium, cisatracurium, mivacurium, rocuronium, and vecuronium. Patients were initially administered 2x the effective dose for 95% of the study drug. After recovery to 10% of baseline neuromuscular function, the neuromuscular blockade was rigidly maintained with an infusion of the study drug at about 10% of baseline function. Neuromuscular drug costs were approximated as drug usage x cost/unit. The initial drug costs were not substantially different for both Parts 1 and 2, but over time, mivacurium became the most expensive drug and cisatracurium the least expensive. In conclusion, based on current costs, cisatracurium is the least expensive intermediate-acting neuromuscular drug. IMPLICATIONS: For children undergoing minor ambulatory procedures of 1-2 h, and continuous intraoperative neuromuscular blockade is indicated, cisatracurium currently is the least expensive drug.

PMID: 11473856, UI: 21367387

Anesth Analg 2001 Aug;93(2):253-9 , 1st contents page

Thoracic epidural bupivacaine attenuates supraventricular tachyarrhythmias after pulmonary resection.

Oka T, Ozawa Y, Ohkubo Y

Division of Anesthesia, Tochigi Cancer Center Hospital, 4-9-13 Yohnan, Utsonomiya-shi, Tochigi 320-0834, Japan. toka@tcc.pref.tochigi.jp

Supraventricular tachyarrhythmias after pulmonary surgery are well described. Some investigators suggest that tachyarrhythmias after thoracic operations may result from the relative sympathotonic status produced by injury to the cardiac parasympathetic nerves. We examined whether postoperative thoracic sympathetic blockade by thoracic epidural bupivacaine might reduce the tachyarrhythmias after pulmonary resection. Fifty patients with lung cancer were randomized to receive epidural bupivacaine (Group B) or epidural morphine (Group M). Patients in Group B were given 6 to 10 mL of 0.25% bupivacaine epidurally, followed by epidural infusion at 3 to 5 mL/h for 3 days, and patients in Group M were given 2 to 3 mg morphine epidurally, followed by morphine infusion at a rate of 0.2 mg/h. Tachyarrhythmias were diagnosed by using the continuous heart rate trend and arrhythmia trend with a central monitoring system. Postoperative analgesia was not statistically different between groups. However, the incidence of postoperative tachyarrhythmias in Group B was significantly less than in Group M (1 of 23 vs 7 of 25, P = 0.0497, Fisher's exact test). The continuous infusion of thoracic epidural bupivacaine can reduce supraventricular tachyarrhythmias compared with epidural morphine infusion, presumably because of attenuation of the sympathotonic status after pulmonary resection. IMPLICATIONS: We examined whether postoperative thoracic sympathetic blockade by thoracic epidural bupivacaine after pulmonary resection might reduce the tachyarrhythmias that may result from the relative sympathotonic status produced by injury to the cardiac parasympathetic nerves. The continuous infusion of thoracic epidural bupivacaine was shown to reduce supraventricular tachyarrhythmias.

Publication Types:

Clinical trial
Randomized controlled trial

PMID: 11473839, UI: 21367370

Anesthesiology 2001 Aug;95(2):568-9

Ventilator failure during use of a new anesthesia machine.

Barahal D, Sims C

Publication Types:

Letter

PMID: 11506142, UI: 21396942

Anesthesiology 2001 Aug;95(2):558-61

Nonanesthetics (nonimmobilizers) and anesthetics display different microenvironment preferences.

Johansson JS, Zou H

Department of Anesthesia and the Johnson Research Foundation, University of Pennsylvania, Philadelphia, USA. johansso@mail.med.upenn.edu

PMID: 11506136, UI: 21396936

Anesthesiology 2001 Aug;95(2):470-7

Nonhalogenated alkane anesthetics fail to potentiate agonist actions on two ligand-gated ion channels.

Raines DE, Claycomb RJ, Scheller M, Forman SA

Harvard Medical School, Boston, Massachusetts, USA. DRaines@partners.org

BACKGROUND: Although ether, alcohol, and halogenated alkane anesthetics potentiate agonist actions or increase the apparent agonist affinity of ligand-gated ion channels at clinically relevant concentrations, the effects of nonhalogenated alkane anesthetics on ligand-gated ion channels have not been studied. The current study assessed the abilities of two representative nonhalogenated alkane anesthetics (cyclopropane and butane) to potentiate agonist actions or increase the apparent agonist affinity of two representative ligand-gated ion channels: the nicotinic acetylcholine receptor and y-aminobutyric acid type A (GABA(A)) receptor. METHODS: Nicotinic acetylcholine receptors were obtained from the electroplax organ of Torpedo nobiliana, and human GABA(A) receptors (alpha1beta2gamma2L) were expressed in human embryonic kidney 293 cells. The Torpedo nicotinic acetylcholine receptors apparent agonist affinity in the presence and absence of anesthetic was assessed by measuring the apparent rates of desensitization induced by a range of acetylcholine concentrations. The GABA(A) receptor's apparent agonist affinity in the presence and absence of anesthetic was assessed by measuring the peak currents induced by a range of GABA concentrations. RESULTS: Neither cyclopropane nor butane potentiated agonist actions or increased the apparent agonist affinity (reduced the apparent agonist dissociation constant) of the Torpedo nicotinic acetylcholine receptor or GABA(A) receptor. At clinically relevant concentrations, cyclopropane and butane reduced the apparent rate of Torpedo nicotinic acetylcholine receptor desensitization induced by low concentrations of agonist. CONCLUSIONS: Our results suggest that the in vivo central nervous system depressant effects of nonhalogenated alkane anesthetics do not result from their abilities to potentiate agonist actions on ligand-gated ion channels. Other targets or mechanisms more likely account for the anesthetic activities of nonhalogenated alkane anesthetics.

PMID: 11506122, UI: 21396922

Anesthesiology 2001 Aug;95(2):364-70

Auditory evoked potential index predicts the depth of sedation and movement in response to skin incision during sevoflurane anesthesia.

Kurita T, Doi M, Katoh T, Sano H, Sato S, Mantzaridis H, Kenny GN

Department of Anesthesiology and Intensive Care, Hamamatsu University School of Medicine, Japan. tadkur@hama-med.ac.jp

BACKGROUND: The auditory evoked potential (AEP) index, which is a single numerical parameter derived from the AEP in real time and which describes the underlying morphology of the AEP, has been studied as a monitor of anesthetic depth. The current study was designed to evaluate the accuracy of AEPindex for predicting depth of sedation and anesthesia during sevoflurane anesthesia. METHODS: In the first phase of the study, a single end-tidal sevoflurane concentration ranging from 0.5 to 0.9% was assigned randomly and administered to each of 50 patients. The AEPindex and the Bispectral Index (BIS) were obtained simultaneously. Sedation was assessed using the responsiveness portion of the observer's assessment of alertness-sedation scale. In the second phase of the study, 10 additional patients were included, and the 60 patients who were scheduled to have skin incisions were observed for movement in response to skin incision at the end-tidal sevoflurane concentrations between 1.6 and 2.6%. The relation among AEPindex, BIS, sevoflurane concentration, sedation score, and movement or absence of movement after skin incision was determined. Prediction probability values for AEPindex, BIS, and sevoflurane concentration to predict depth of sedation and anesthesia were also calculated. RESULTS: The AEPindex, BIS, and sevoflurane concentration correlated closely with the sedation score. The prediction probability values for AEPindex, BIS, and sevoflurane concentration for sedation score were 0.820, 0.805, and 0.870, respectively, indicating a high predictive performance for depth of sedation. AEPindex and sevoflurane concentration successfully predicted movement after skin (prediction probability = 0.910 and 0.857, respectively), whereas BIS could not (prediction probability = 0.537). CONCLUSIONS: Auditory evoked potential index can be a guide to the depth of sedation and movement in response to skin incision during sevoflurane anesthesia.

Publication Types:

Clinical trial

PMID: 11506107, UI: 21396907

Anesthesiology 2001 Aug;95(2):343-8

Fiberoptic orotracheal intubation on anesthetized patients: do manipulation skills learned on a simple model transfer into the operating room?

Naik VN, Matsumoto ED, Houston PL, Hamstra SJ, Yeung RY, Mallon JS, Martire TM

Centre for Research in Education, Department of Anesthesia, Mt Sinai Hospital, Univesity of Toronto, Ontario, Canada.

BACKGROUND: With increasing pressure to use operating room time efficiently, opportunities for residents to learn fiberoptic orotracheal intubation in the operating room have declined. The purpose of this study was to determine whether fiberoptic orotracheal intubation skills learned outside the operating room on a simple model could be transferred into the clinical setting. METHODS: First-year anesthesiology residents and first- and second-year internal medicine residents were recruited. Subjects were randomized to a didactic-teaching-only group (n = 12) or a model-training group (n = 12). The didactic-teaching group received a detailed lecture from an expert bronchoscopist. The model-training group was guided, by experts, through tasks performed on a simple model designed to refine fiberoptic manipulation skills. After the training session, subjects performed a fiberoptic orotracheal intubation on healthy, consenting, anesthetized, paralyzed female patients undergoing elective surgery with predicted "easy" laryngoscopic intubations. Two blinded anesthesiologists evaluated each subject. RESULTS: After the training session, the model group significantly outperformed the didactic group in the operating room when evaluated with a global rating scale (P < 0.01)and checklist (P0.05). Model-trained subjects completed the fiberoptic orotracheal intubation significantly faster than didactic-trained subjects (P < 0.01). Model-trained subjects were also more successful at achieving tracheal intubation than the didactic group (P < 0.005). CONCLUSION: Fiberoptic orotracheal intubation skills training on a simple model is more effective than conventional didactic instruction for transfer to the clinical setting. Incorporating an extraoperative model into the training of fiberoptic orotracheal intubation may greatly reduce the time and pressures that accompany teaching this skill in the operating room.

Publication Types:

Clinical trial
Randomized controlled trial

PMID: 11506104, UI: 21396904

Anesthesiology 2001 Aug;95(2):314-23

Concentration-effect relationship of cisatracurium at three different dose levels in the anesthetized patient.

Bergeron L, Bevan DR, Berrill A, Kahwaji R, Varin F

Faculte de Pharmacie, Universite de Montreal, Quebec, Canada.

BACKGROUND: The linearity of cisatracurium elimination and its concentration-effect relation were determined as part of a traditional rich data study with three dose levels in patients receiving balanced anesthesia. METHODS: Forty-eight adults with American Society of Anesthesiologists status I-II were randomized to receive an intravenous bolus dose of 0.075, 0.15, or 0.30 mg/kg cisatracurium. Anesthesia was induced and maintained with nitrous oxide-oxygen, propofol, and fentanyl. The mechanical response of the adductor pollicis muscle was recorded. Arterial blood samples were collected over 8 h. Cisatracurium, laudanosine, and the monoquaternary alcohol concentrations were measured by high-performance liquid chromatography. To assess the relative contribution of the input function, a parametric (assuming elimination from both the central and peripheral compartments) and a nonparametric pharmacokinetic-pharmacodynamic model were both applied to data. RESULTS: Dose proportionality of the body disposition of cisatracurium and its two major metabolites at doses up to 0.30 mg/kg was confirmed. With the parametric approach, the effect compartment concentration at 50% block (EC50) significantly increased with the dose (136 vs. 157 vs. 209 ng/ml), whereas the effect compartment equilibration rate constant decreased (0.0675 vs. 0.0568 vs. 0.0478 min(-1)). A similar dose-dependent effect of the pharmacokinetic-pharmacodynamic relation was observed with the nonparametric approach, but the trend was 50% less pronounced. CONCLUSION: A dose-related change in pharmacokinetic-pharmacodynamic parameters was identified with both modeling approaches. A pharmacokinetic origin was ruled out, although no definite explanation of the underlying mechanism could be provided. These findings suggest that doses relevant to the anesthetic practice be used for estimation of EC50.

Publication Types:

Clinical trial
Randomized controlled trial

PMID: 11506100, UI: 21396900

Anesthesiology 2001 Aug;95(2):307-13

Comparison of metaraminol and ephedrine infusions for maintaining arterial pressure during spinal anesthesia for elective cesarean section.

Ngan Kee WD, Lau TK, Khaw KS, Lee BB

Department of Anaesthesia and Intensive Care, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin. warwick@cuhk.edu.hk

BACKGROUND: Although ephedrine is usually recommended as the first-line vasopressor in obstetrics, its superiority over other vasopressors has not been proven in humans. METHODS: In a double-blind study, the authors randomized women having elective cesarean section with spinal anesthesia to receive an intravenous infusion of ephedrine, starting at 5 mg/min (n = 25), or metaraminol, starting at 0.25 mg/min (n = 25), titrated to maintain systolic arterial pressure in the target range 90-100% of baseline. Umbilical cord gases, maternal hemodynamics, uterine artery puLsatility index, and Apgar scores were compared. RESULTS: Systolic arterial pressure was maintained more closely in the target range in the metaraminol group compared with the ephedrine group. In the metaraminol group, umbilical arterial pH was greater (median and interquartile range, 7.31 and 7.31-7.33 vs. 7.24 and 7.14-7.29; P < 0.0001), and umbilical venous pH was greater (7.36 and 7.35-7.38 vs. 7.33 and 7.26-7.34; P < 0.0001) compared with the ephedrine group. No patient in the metaraminol group had umbilical arterial pH less than 7.2, compared with nine patients (39%) in the ephedrine group (P = 0.0005). Apgar scores were similar between groups. Changes in uterine artery pulsatility index were similar between groups. CONCLUSIONS: When used by infusion to maintain arterial pressure during spinal anesthesia for cesarean section, metaraminol was associated with less neonatal acidosis and more closely controlled titration of arterial pressure compared with ephedrine.

Publication Types:

Clinical trial
Randomized controlled trial

PMID: 11506099, UI: 21396899

Br J Anaesth 2001 Sep;87(3):512-5

Spinal cord injury caused by direct damage by local anaesthetic infiltration needle.

Absalom AR, Martinelli G, Scott NB

University Department of Anaesthesia, Glasgow Royal Infirmary, Alexandra Parade, Glasgow G31 2ER, UK. Department of Anaesthesia, HCI International Medical Centre, Clydebank, Glasgow G81 4HX, UKCorresponding author.

[Medline record in process]

We describe a case of spinal cord injury caused by direct trauma from a local anaesthetic infiltration needle. During local anaesthetic infiltration before placement of an epidural catheter, the patient suddenly rolled over onto her back, causing the infiltrating needle to advance all the way to its hub. She immediately showed signs of spinal cord injury, confirmed by MRI scan. However, her neurological status gradually improved, and on discharge she was able to walk, with a sensory deficit localized to her left foot. Br J Anaesth 2001; 87: 512-15

PMID: 11517144, UI: 21407626

Br J Anaesth 2001 Sep;87(3):505-7

Onset of propofol-induced burst suppression may be correctly detected as deepening of anaesthesia by approximate entropy but not by bispectral index.

Bruhn J, Bouillon TW, Shafer SL

Department of Anesthesiology, Stanford University School of Medicine, Stanford, CA, USA.

[Medline record in process]

The bispectral index (BIS) is a complex EEG variable that combines several disparate descriptors of the EEG into a single value. Approximate entropy is a novel EEG measure that quantifies the regularity of a data time series such as EEG. We report two patients in which the EEG effect of propofol was quantified very similarly by BIS and approximate entropy. However, at the beginning of burst suppression of the EEG, BIS did not indicate an increased anaesthetic drug effect, while approximate entropy did.

PMID: 11517141, UI: 21407623

Br J Anaesth 2001 Sep;87(3):499-501

Haemodynamic effects of three doses of dihydroergotamine during spinal anaesthesia.

Critchley LA, Woodward DK

Department of Anaesthesia and Intensive Care, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, SAR, ChinaCorresponding author.

[Medline record in process]

We performed a randomized study comparing the haemodynamic effects of three doses of the vasopressor dihydroergotamine (DHE) (5, 10 and 15 &mgr;g kg(-1)) in 30 ASA 1 and 2 patients, aged 53-87 yr, undergoing spinal anaesthesia. Non-invasive systolic arterial pressure (SAP), heart rate and central venous pressure (CVP) were recorded continuously for 25 min. Intravenous fluids were withheld during this period. All three doses of DHE reversed the lowering effects of spinal anaesthesia on SAP and CVP (P<0.0001), and these effects were smooth in onset and sustained. Whereas the lowest (5 &mgr;g kg(-1)) dose restored SAP and CVP to near prespinal values, the higher (10 and 15 &mgr;g kg(-1)) doses resulted in above-baseline increases in SAP of 7% and in CVP of 2.7 cm H(2)O (P<0.05). The haemodynamic profile of DHE makes it a useful agent for managing hypotension during spinal anaesthesia. A dose of 5-10 &mgr;g kg(-1) is recommended. Br J Anaesth 2001; 87: 499-501

PMID: 11517139, UI: 21407621

Br J Anaesth 2001 Sep;87(3):497-8

Arterial and mixed venous xenon blood concentrations in pigs during wash-in of inhalational anaesthesia.

Nalos M, Wachter U, Pittner A, Georgieff M, Radermacher P, Froeba G

Universitatsklinik fur Anasthesiologie, Universitat Ulm, Sektion Anasthesiologische Pathophysiologie und Verfahrensentwicklung, Parkstrasse 11, D-89073 Ulm, Germany.

[Medline record in process]

There are no data available on the kinetics of blood concentrations of xenon during the wash-in phase of an inhalation anaesthesia aiming at 1 MAC end-expiratory concentration. Therefore, we anaesthetized eight pigs with continuous propofol and fentanyl and measured arterial, mixed venous and end-expiratory xenon concentrations by gas chromatography-mass spectrometry 1, 2, 3, 4, 5, 7, 10, 15, 20, 30, 60 and 120 min after starting the anaesthetic gas mixture [67% xenon/33% oxygen; 3 litre x min(-1) during the first 10 min, thereafter minimal flow with 0.48 (SD 0.03) litre x min(-1)]. End-expiratory xenon concentrations plateaued (defined as <5% change from the preceding value) at 64 (6) vol% after 7 min, and arterial and mixed venous xenon concentrations after 5 and 15 min respectively. The highest arterio-venous concentration difference occurred after 3 min. Using the Fick principle, we calculated a mean xenon uptake of 3708 (829) and 9977 (3607) ml after 30 and 120 min respectively.

PMID: 11517138, UI: 21407620

Br J Anaesth 2001 Sep;87(3):421-8

Quantitative EEG changes associated with loss and return of consciousness in healthy adult volunteers anaesthetized with propofol or sevoflurane.

Gugino LD, Chabot RJ, Prichep LS, John ER, Formanek V, Aglio LS

Department of Anesthesia, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.

[Medline record in process]

Significant changes in topographic quantitative EEG (QEEG) features were documented during induction and emergence from anaesthesia induced by the systematic administration of sevoflurane and propofol in combination with remifentanil. The goal was to identify those changes that were sensitive to alterations in the state of consciousness but independent of anaesthetic protocol. Healthy paid volunteers were anaesthetized and reawakened using propofol/remifentanil and sevoflurane/remifentanil, administered in graded steps while the level of arousal was measured. Alterations in the level of arousal were accompanied by significant QEEG changes, many of which were consistent across anaesthetic protocols. Light sedation was accompanied by decreased posterior alpha and increased frontal/central beta power. Frontal power predominance increased with deeper sedation, involving alpha and, to a lesser extent, delta and theta power. With loss of consciousness, delta and theta power increased further in anterior regions and also spread to posterior regions. These changes reversed with return to consciousness.

PMID: 11517126, UI: 21407608

Br J Anaesth 2001 Sep;87(3):406-14

Volume kinetics of Ringer's solution during induction of spinal and general anaesthesia.

Ewaldsson CA, Hahn RG

Karolinska Institute, Department of Anaesthesia, Soder Hospital, S-118 83 Stockholm, SwedenCorresponding author.

[Medline record in process]

The kinetics of an i.v. infusion of 20 ml kg(-1) of Ringer's solution over 60 min was studied in patients undergoing spinal (n=10) and general (n=10) anaesthesia. The induction resulted in similar changes in volume kinetic parameters in both groups. When a one-volume model was employed (n=8), however, the infusion expanded a smaller body fluid space in the four patients who had received preoperative enteric lavage (3.3 vs 8.3 litres), which is consistent with hypovolaemia. When a two-volume model was statistically justified (n=12), the induction reduced the rate of fluid equilibration between a fairly small central (V(1), mean 1.4 litres) and a peripheral body fluid space by about 50% (P<0.01). The kinetic analysis suggested that a rapid fluid load of 350 ml given over 2 min just after the induction could possibly prevent arterial hypotension because of central hypovolaemia. This was confirmed in five additional patients. Br J Anaesth 2001; 87: 406-14

PMID: 11517124, UI: 21407606

Br J Anaesth 2001 Sep;87(3):385-9

Predictive factors of early morphine requirements in the post-anaesthesia care unit (PACU).

Dahmani S, Dupont H, Mantz J, Desmonts JM, Keita H

Department of Anaesthesia and Intensive Care, Hospital Bichat, 46 rue Henri Huchard, F-75018 Paris, FranceCorresponding author.

[Medline record in process]

Use of morphine by titration in the post-anaesthesia care unit (PACU) is often the first step in postoperative pain management. This approach provides rapid analgesia but shows a wide inter-individual variability in morphine requirements and may prolong patient stay in the PACU. The aim of this study was to identify the patient characteristics, surgical, anaesthetic, and postoperative factors predictive of early morphine requirements. The study included 149 patients undergoing various non-cardiac surgical procedures under general anaesthesia. In the multiple regression analysis of nine variables, only ethnicity (Caucasian), emergency surgery, major surgery, surgery exceeding 100 min, and pain score on arrival in PACU were predictive factors of morphine requirements. This observational study identifies for the first time independent predictive factors of morphine requirements in the early postoperative period. Future studies are warranted to evaluate the impact of intervention on these factors and any resulting improvement in postoperative pain treatment. Br J Anaesth 2001; 87: 385-9

PMID: 11517121, UI: 21407603

Br J Anaesth 2001 Sep;87(3):380-4

Editorial II: Fatty acid amides are putative endogenous ligands for anaesthetic recognition sites in mammalian CNS.

Laws D, Verdon B, Coyne L, Lees G

[Medline record in process]

PMID: 11517120, UI: 21407602

J Cardiothorac Vasc Anesth 2001 Jun;15(3):356-7

Severe dental pain during carotid endarterectomy under cervical plexus block.

Madi-Jebara S, Yazigi A, Haddad F, Hayek G

Department of Anesthesia and Intensive Care, Hotel-Dieu de France Hospital, Saint-Joseph University, Beirut, Lebanon.

PMID: 11426369, UI: 21319118

J Cardiothorac Vasc Anesth 2001 Jun;15(3):288-92

Comparison of continuous thoracic epidural and paravertebral blocks for postoperative analgesia after minimally invasive direct coronary artery bypass surgery.

Dhole S, Mehta Y, Saxena H, Juneja R, Trehan N

Department of Anaesthesia and Cardiac Surgery, Escorts Heart Institute and Research Centre, New Delhi, India.

OBJECTIVE: To compare continuous thoracic epidural analgesia (TEA) and paravertebral block (PVB) for postoperative analgesia in patients undergoing minimally invasive direct coronary artery bypass (MIDCAB) surgery for quality of analgesia, complications, compliance to chest physiotherapy, hemodynamics, and respiratory effects. DESIGN: Prospective, randomized study. SETTING: Specialty research hospital. PARTICIPANTS: Forty-one consenting patients undergoing MIDCAB surgery. INTERVENTIONS: Patients in the TEA group had an epidural catheter inserted at the T4-5 interspace, whereas patients in the PVB group had a catheter inserted in the paravertebral space on the left side at the T4-5 level. MEASUREMENTS AND MAIN RESULTS: Parameters evaluated included visual analog scale pain scores at rest and while coughing, supplemental analgesic requirement, complications, hemodynamics, and respiratory parameters. Measurements were made at 2-hour intervals for 12 hours beginning at 10 minutes after endotracheal extubation. There was no statistically significant difference in visual analog scale scores and requirement of supplemental analgesia between the 2 groups. Cardiac index at 4 hours and 6 hours was significantly higher in the TEA group. Patients in the PVB group had significantly lower respiratory rates at 8, 10, and 12 hours. All other parameters were comparable. In 1 patient, the epidural space could not be catheterized. One patient in the TEA group had transient hypotension, and 1 patient complained of backache at the site of the epidural catheter insertion. CONCLUSION: PVB is as effective as TEA for postoperative analgesia after MIDCAB surgery. PVB is technically easier than TEA and may be safer than TEA because no complications were seen in the PVB group. Copyright 2001 by W.B. Saunders Company.

Publication Types:

Clinical trial
Randomized controlled trial

PMID: 11426357, UI: 21319106