Pulmonary effects of bupivacaine, ropivacaine, and levobupivacaine in parturients undergoing spinal anaesthesia for elective caesarean delivery: a randomised controlled study

BACKGROUND

Spinal anaesthesia is the method of choice for elective caesarean delivery, but has been reported to worsen dynamic pulmonary function when using bupivacaine. Similar investigations are lacking for ropivacaine and levobupivacaine. We have therefore compared the pulmonary effects of intrathecal bupivacaine, ropivacaine and levobupivacaine used for caesarean delivery.

METHODS

Forced vital capacity, forced expiratory volume in the first second, and peak expiratory flow rate were measured in 48 parturients before and after onset of spinal anaesthesia using either 0.5% bupivacaine 10 mg, 1% ropivacaine 20 mg, or 0.5% levobupivacaine 10 mg. Apgar scores and umbilical arterial pH were recorded.

RESULTS

The final level of sensory blockade was not different between groups. Forced vital capacity was significantly decreased with bupivacaine (3.6+/-0.5 L to 3.5+/-0.4 L, P<0.05) and ropivacaine (3.2+/-0.4 L to 3.1+/-0.5 L, P<0.05), but not with levobupivacaine (3.6+/-0.5 L to 3.4+/-0.6 L). Forced expiratory volume during the first second was not decreased in any group. Peak expiratory flow rate was significantly decreased with ropivacaine (5.5+/-1.5 L/s to 5.0+/-1.1 L/s, P<0.05) and levobupivacaine (from 6.0+/-1.1 L/s to 5.2+/-0.9 L/s, P<0.01). Neonatal vital parameters did not differ between the three groups.

CONCLUSIONS

Decreases in maternal pulmonary function tests were similar following spinal anaesthesia with bupivacaine, ropivacaine, or levobupivacaine for caesarean delivery. The clinical maternal and neonatal effects of these alterations appeared negligible.

Bewertung eines Anatomieworkshops f�r die Regionalan�sthesieausbildung

BACKGROUND

The aim of the present investigation was to survey former participants (n=869) of a cadaver workshop using a mail questionnaire to assess the demographic data and the impact of these courses on daily practice.

METHODS

The deadline for acceptance of return mail was 60 days. Descriptive statistics were employed for analysis of results.

RESULTS

The response rate was 36.7% and the course was judged to be recommendable by 98.2%. The average course attendant was board certified and had spent a mean time of 9+/-6 years in anesthesiology. The highest quality and degree of subsequent practicability in daily routine was attributed to peripheral nerve block training on cadavers. Of the course participants two-thirds performed regional anesthesia procedures more often following attendance. The majority of course attendants had to defray at least a part of the course fee themselves, and one-third was required to invest leisure time to attend.

CONCLUSION

Attendance of a cadaver workshop increased knowledge of clinical anatomy and enhanced performance of regional anesthesia procedures. Courses of this format constitute a currently underestimated adjunct to contemporary regional anesthesia education.

[Tumorectomy in conscious patient with suspected pregnancy associated breast cancer under cervical epidural anesthesia]

In this report we present a 35 year old pregnant woman (no significant disease in patient history, non smoker, primipara, gestational week 15) who had to undergo elective tumorectomy due to suspected pregnancy associated breast cancer. General anesthesia during pregnancy can potentially be harmful for the fetus (hypoxia, acidosis, premature delivery, teratogenicity). We decided to anesthetize the patient with a cervical segmental epidural block.

Accuracy in estimating the correct intervertebral space level during lumbar, thoracic and cervical epidural anaesthesia

BACKGROUND

Even in the absence of factors concealing anatomical landmarks, high failure rates in correctly determining a given lumbar interspace have been reported.

METHODS

Therefore, it was the aim of the present study to compare the assessed and factual level (determined by computed tomography) of epidural puncture in attending a regional anaesthesia cadaver workshop. Eighty-two anaesthetists performed 117 punctures.

RESULTS

Vertebral interspaces between T8-L4 were correctly identified more often than those between C3-T5 (P < 0.05). Identification of an arbitrarily chosen vertebral interspace was excellent in both the cervical/high thoracic and thoracic/lumbar regions.

CONCLUSION

As previously conjectured only for the lumbar region, we could confirm the tendency of anaesthetists to perform neuraxial puncture more cranially than expected also for the thoracic and cervical regions. The large majority of punctures (93.7%) was performed within one interspace of the predicted level.

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

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.

Rectally administered dimenhydrinate reduces postoperative vomiting in children after strabismus surgery

We have investigated the effectiveness of rectally administered dimenhydrinate on postoperative vomiting in children undergoing strabismus surgery, in a double-blind, randomized, placebo-controlled study. In one group, dimenhydrinate 50 mg was administered rectally 30 min before starting anaesthesia, whereas in the control group, placebo suppositories were given. Children who received dimenhydrinate showed a significantly (P < 0.001) lower incidence of vomiting (15%) than those in the control group (75%). We conclude that rectal administration of dimenhydrinate is an effective means of reducing postoperative vomiting in children undergoing strabismus surgery.

[Opioid therapy in Austria: results and analysis of a survey]

INTRODUCTION

Many causes are given as the main reason for inadequate pain therapy. The objective of our study was to demonstrate the current position of doctors in general practice all over Austria who prescribe prescriptions.

METHODS

A total of 5,359 questionnaires were sent out to general practitioners in all federal states of Austria. These questionnaires contained 21 main questions on subjects relevant to pain therapy.

RESULTS

On average, 16% of all general practitioners returned the questionnaires; 89.3% of these are acquainted with the WHO graduated scale, 87% have prescribed strong opioids. Old prejudices such as concerns about the side effects are hardly to be found now. Modern therapy strategies are used.

CONCLUSION

Based on the data at hand, pain therapy for patients should be excellent. The reality, however, is somewhat different. The large number of doctors who did not reply makes it enormously difficult to make a statement about the position of pain therapy in Austria.

Extended duration of action of rocuronium in postpartum patients

We studied the time course of action of a single bolus of 600 micrograms/kg rocuronium given during anesthesia with propofol, fentanyl, and nitrous oxide was studied in 12 nonpregnant and 12 postpartum patients. Neuromuscular effects were quantified by recording the indirectly evoked twitch response of the adductor pollicis muscle after ulnar nerve stimulation. In all patients, the trachea was intubated 60 s after administration of rocuronium. Onset time was similar in both groups (nonpregnant: 91 +/- 28 s vs. postpartum: 95 +/- 30 s), with the time to 25% twitch recovery being significantly longer (P < 0.001) in the postpartum patients (31.1 +/- 3.6 min) compared with the nonpregnant group (24.9 +/- 4.0 min). The time required for recovery from 25% to 75% of the control twitch response after reversal with neostigmine and atropine was significantly longer (P = 0.003) in postpartum (4.8 +/- 0.9 min) than in nonpregnant patients (3.2 +/- 0.6 min). These data suggest that pregnancy-induced changes result in prolonged effects of rocuronium in postpartum patients.

The onset of pipecuronium following application of the priming principle

Pipecuronium bromide, a long acting non-depolarizing neuromuscular blocking agent was administered to four groups of 10 patients using the priming technique. The effects of the combination of two different priming doses (0.01 or 0.015 mg kg-1) given at two different time intervals (3 or 4 min) before the 'main' intubating dose (0.07 or 0.065 mg kg-1) were investigated. Onset times were recorded and the intubation conditions were scored and compared with a group of patients receiving the same total amount of pipecuronium (0.08 mg kg-1) in a single bolus injection. Intubating conditions at 90 s after administration of the intubating dose were found to be significantly improved in all primed groups but the onset times, evaluated using the response of the adductor pollicis muscle to a single twitch stimulation, were similar to that observed after the single bolus injection. The optimal priming combination is considered to be 0.01 mg kg-1 of pipecuronium followed 3 to 4 min later by 0.07 mg kg-1.

Rocuronium bromide: time-course of action in underweight, normal weight, overweight and obese patients

The duration of action and recovery of 0.6 mg kg-1 rocuronium in underweight, normal weight, overweight and obese patients were investigated. Forty-eight patients were divided into four groups, according to their body mass index, and were given 0.6 mg kg-1 rocuronium. The onset time, the duration 25% and either the spontaneous or induced recovery were measured according to the random assignment. The onset time in the obese group was shorter 60 (50-90) s compared to the other groups (underweight: 95 (40-320) s, normal: 95 (50-200) s, overweight: 90 (50-260) s, but the difference did not reach the level of statistical significance. The duration 25% was slightly prolonged in the obese patients (31.5 (21.0-61.0) min) when compared to the underweight (25.0 (15.0-37.0) min), normal weight (26.0 (20.0-36.0) min) and overweight (27.0 (19.0-35.0) min) patients. No differences were observed in spontaneous (9.5-12.5 min) and induced (2.5-3.5 min) recovery.

The use of rocuronium (ORG 9426) in patients with chronic renal failure

The pharmacodynamics of an initial dose of 0.6 mg.kg-1 rocuronium followed by three maintenance doses of 0.15 mg.kg-1 were studied during nitrous oxide/oxygen/isoflurane anaesthesia in patients with normal renal function (n = 12) and chronic renal failure (n = 12). The mean (SD) duration (min) of block after the initial dose was 28.0 (5.5) and 25.6 (11.7) respectively. The mean (SD) duration (min) of the effect of the three maintenance doses was 15.3 (4.0) and 14.2 (7.0); 17.3 (3.2) and 17.4 (8.7); 18.1 (2.8) and 19.1 (10.1) for the normal and renal failure patients respectively. The induced and spontaneous recovery indices were 3.7 (0.7) and 17.1 (6.9) in the normal group compared with 3.9 (0.5) and 19.0 (12.5) in the renal failure group and these values did not differ between the two groups. In this small study rocuronium appears to be suitable for patients with chronic renal failure. There is no evidence of prolonged block even when the drug is given in repeated doses for maintenance.

Evaluation of the time course of action of maintenance doses of rocuronium (ORG 9426) under halothane anaesthesia

The time course of action of rocuronium was compared using three different sizes of maintenance doses after at least three subsequent administrations of the same repeat dose in each patients under halothane anaesthesia. Following endotracheal intubation facilitated with 0.6 mg.kg-1 rocuronium (ORG 9426), muscle relaxation was maintained in three groups each consisting of ten patients, using increments of equal repeat doses of either 75 micrograms.kg-1, 150 micrograms.kg-1 or 225 micrograms.kg-1 equivalent to 1/4, 1/2 and 3/4 of the ED95 of this new compound, respectively. Maintenance doses were administered when the twitch height depression induced by the previous dose returned to 25% of its control value. The clinical duration of the intubating dose averaged 27 +/- 7.5 min (mean +/- s.d.). The time course of action of the various maintenance doses depended on their size, but not on the number of administrations. The durations of repeat doses averaged 8-9 min, 14-16 min and 19-23 min after the low, medium and high maintenance doses, respectively. No overt cumulative effects were observed.

Evaluation of the endotracheal intubating conditions of rocuronium (ORG 9426) and succinylcholine in outpatient surgery

The time-course of action and tracheal intubating conditions of rocuronium and succinylcholine under intravenous anesthesia with propofol, alfentanil, and nitrous oxide were studied in 30 patients undergoing outpatient surgery. The neuromuscular effects of both drugs were quantified by recording the indirectly evoked twitch response of the adductor pollicis muscle after ulnar nerve stimulation (0.1 Hz, 0.2 ms supramaximal stimuli). Patients were given either 0.6 mg/kg rocuronium (n = 20) or 1 mg/kg succinylcholine (n = 10) intravenously. Sixty seconds after the administration of the muscle relaxant, the trachea was intubated and the intubating conditions were scored by a "blinded" assessor. Intubating conditions were not different (P = 0.34) between the rocuronium and succinylcholine groups. The onset and duration of neuromuscular blockade were shorter with succinylcholine than with rocuronium. The depression of the twitch response to 5% of control value occurred in 0.8 +/- 0.1 min with 1 mg/kg succinylcholine and 1.2 +/- 0.5 min with 0.6 mg/kg rocuronium (P less than 0.01). The recovery of the twitch response to 25%, 75%, and 90% of its control value was shorter after succinylcholine (P less than 0.001) and occurred at 8.1 +/- 2.6, 10.3 +/- 3.9, 11.3 +/- 4.6 and 25.3 +/- 5.0, 33.1 +/- 5.9, 36.1 +/- 6.3 min after succinylcholine and rocuronium, respectively. Also the time required for spontaneous recovery from 25% to 75% of the control twitch response was significantly shorter (P less than 0.001) after succinylcholine (2.2 +/- 1.4 min) than after rocuronium (7.8 +/- 2.1 min). It is concluded that in spite of the pharmacodynamic differences between succinylcholine and rocuronium, the intubating conditions after administration of both compounds are similar and develop at the same rate.

Prediction of non-survival after trauma: Innsbruck Coma Scale

421 severely injured patients admitted to a major trauma centre in Innsbruck during the ten years, 1981 to 1990, were investigated retrospectively for early prediction of survival by means of the Innsbruck Coma Scale (ICS). All 79 patients scoring 0 or 1 died within 21 days. The findings of this study indicate that the ICS allows a highly accurate prediction of non-survival in patients with scores of 0 or 1 even at the time of first examination after trauma.

[Values of atrial natriuretic peptide (ANP) and cyclic guanosine monophosphate (cGMP) in cardioversion]

We investigated atrial natriuretic peptide (ANP) and cyclic guanosine monophosphate (cGMP) in patients undergoing elective direct current cardioversion (CV group) due to atrial fibrillation (n = 9) or atrial flutter (n = 3). Anesthesia for cardioversion (CV) was induced with propofol 1.5 mg/kg. Conversion was achieved in all patients. Before CV all patients had elevated ANP and cGMP plasma levels. After CV the concentrations of ANP and cGMP decreased significantly within 15 and 30 minutes (p less than 0.01), respectively. Only one patient in the CV group showed increasing ANP and cGMP levels although his heart rate had decreased after CV and his blood pressure remained stable. High concentrations of ANP and cGMP might possibly be a compensatory mechanism of cardiac dysfunction. To study the influence the anesthetic agent on plasma levels of ANP and cGMP, we investigated six patients anesthetized with propofol for high-density radiation (HDR group). The data from this control group showed that propofol did not influence the plasma levels of ANP and cGMP. ANP correlated statistically significantly (p less than 0.05) with cGMP in both groups (r = 0.88 and 0.76 in the HDR and CV groups, respectively). In addition, we found a cGMP release of 149.6 +/- 17.6 per mol ANP in the HDR group, in the CV group the release was 109 +/- 54.2 cGMP per mol ANP. This phenomenon could be due to minor response of target cells to ANP stimulation (receptor down-regulation) in patients with heart disease. In conclusion, ANP and cGMP levels decreased after successful cardioversion.(ABSTRACT TRUNCATED AT 250 WORDS)

Propofol for direct current cardioversion in cardiac risk patients

We investigated 69 patients (most belonging to NYHA classes II and III) undergoing elective direct current cardioversion of atrial fibrillation (46 patients) and atrial flutter (23 patients), respectively. Without premedication anaesthesia was induced with the new soya bean emulsion of propofol ('Diprivan') 1.2 mg.kg-1 over 45 s. Recovery time was measured from the start of the anaesthetic injection to the moment at which the patients regained consciousness. Completeness of recovery was assessed with two methods: opening eyes on command and time orientation. Good amnesia was observed in all patients. Conversion was achieved in all but seven patients (90%). After injection of propofol, the mean arterial pressure decreased slightly (2% below baseline). Induction of anaesthesia and successful DCC effected a statistically significant decrease in both the heart rate and the rate pressure product. Eleven patients required assisted ventilation for 2 min due to respiratory depression. Fifteen patients developed arrhythmias. Side-effects, such as myocloni, recall or vomiting, were not observed. In conclusion, propofol may well prove to be the anaesthetic of choice for DCC in cardiac patients because of good amnesia, low incidence of side-effects and short recovery time (mean 5.3 min).

[Pethidine or nalbuphine for obstetric analgesia?]

Because of the risk of ventilatory depression, agonistic and partially agonistic/antagonistic opiates are well suited for providing pain relief in obstetrics. We compared two groups of 20 women each with pregnancy on term who received equipotent doses of nalbuphin (0.1 mg/kg) and pethidin (0.8 mg/kg) intramuscularly. We found a significantly longer (6h) and better analgesic effect in the nalbuphin group but also a significantly more pronounced sedation. Other side effects were fewer in this last-named group. There were no differences in the behaviour of the babies between both groups. We consider that because of the "ceiling effect" of ventilatory depression, nalbuphin may allow better analgesia without the risk of ventilatory depression of both mother and newborn.

Thrombotic occlusion of an umbilical vein varix causing fetal death

Acute thrombosis of an umbilical vein varix in combination with a single umbilical artery is a rare cause of fetal death. We now report such a case.

Comparison of vecuronium- and atracurium-induced neuromuscular blockade in postpartum and nonpregnant patients

The time-course of action of 0.1 mg/kg vecuronium and 0.5 mg/kg atracurium was investigated in nonpregnant and in postpartum patients within 4 days after delivery. The clinical duration of vecuronium, but not that of atracurium, was significantly prolonged in the latter group (P less than 0.001) and averaged 36 +/- 6 and 37 +/- 4 min for atracurium and 32 +/- 6 and 49 +/- 10 min for vecuronium in nonpregnant and in postpartum patients, respectively (mean +/- SD). In additional in vitro experiments in the rat phrenic nerve-hemidiaphragm preparation no difference could be observed in the neuromuscular blocking effects of vecuronium in postpartum and nonpregnant female rats. It is concluded that pregnancy-induced changes in liver blood flow and/or competition for the liver uptake of sexual hormones might interfere with the hepatic clearance of vecuronium in postpartum patients and thereby cause the observed prolongation of neuromuscular blockade.

Maintenance of surgical muscle relaxation by repeat doses of vecuronium and atracurium at three different dose levels

The time-course of the neuromuscular effects of vecuronium (n = 25) and atracurium (n = 25) has been compared at three different levels of maintenance dose in anaesthetized patients. Following intubation with vecuronium 0.1 mg kg-1 or atracurium 0.5 mg kg-1, surgical muscle relaxation was maintained by using increments of equipotent maintenance doses equivalent to 0.5, 1.0 and 1.5 x ED95 for each drug. Repeat doses were administered each time the twitch height, depressed by the previous dose, returned to 25% of its control value. The apparent increase in the duration of action, i.e. the difference between the duration of the last and the first maintenance dose, did not reach statistical significance and approximated 3 +/- 2, 6 +/- 4, 11 +/- 5 and 3 +/- 2, 8 +/- 13, 5 +/- 7 min following the low, medium and high maintenance doses of vecuronium and atracurium, respectively.

[The automated determination of the dibucaine number using the Greiner G450 selective analyzer. A routine parameter of significance?]

Patients who are homozygous for an atypical pseudocholinesterase enzyme (PCHE) suffer a prolonged neuromuscular block after succinylcholine application. In order to determine which patients have atypical PCHE preoperatively, an automated method using the Greiner G450 analyzer was developed.

PATIENTS AND METHODS

The contribution of blocked and unblocked PCHE by dibucaine hydrochloride (optimal concentration 10(-4) mol/l;) was determined in 113 patients (ASA groups 1-2) and the dibucaine number (DN) was evaluated.

RESULTS

According to the DN, the patients were subdivided into three groups: group A (PCHE 5.01 +/- 1.64 kU/l, DN 74.47 +/- 0.87); group B (PCHE 4.28 +/- 3.41 kU/l, DN 64.95 +/- 3.41); group C (PCHE 1.33 +/- 0.54 kU/l, DN 13.08 +/- 2.19;). PCHE and DN of group A corresponded with normal standard values, whereas the patients in groups B and C could be considered to be patients with heterozygous and homozygous atypical PCHE, respectively.

CONCLUSIONS

Our data indicate that an automated analysis of blocked and unblocked PCHE with the Greiner G450 can be easily done in a routine laboratory. By interpreting the DN, the possible risks of delayed succinylcholine degradation can probably be prevented.

[The dose-response relationship and time course of the neuromuscular blockade by alcuronium]

Although alcuronium has been in clinical use for almost 40 years, there is still considerable controversy in the literature regarding its neuromuscular blocking potency, the time course of the drug action and the side effects. The aim of this study was to investigate the dose-response relationship of alcuronium and to compare the time course of its neuromuscular effects with vecuronium following intubation doses of both compounds. METHODS. The study was carried out in two parts. In the first part 60 patients and in the second part 30 consenting ASA class I or II patients 20-60 years of age were included. The patients were undergoing elective gynecological or intra-abdominal operations. In the first part the patients received six different doses of alcuronium (60, 90, 120, 150, 180 or 210 micrograms/kg) in order to establish its dose-response relationship. Each dose was administered to ten patients. In the second part patients received either 300 micrograms/kg alcuronium (n = 15) or 100 micrograms/kg vecuronium (n = 15), and the time course of these two compounds (onset time, duration 25%, duration 75% and the recovery index) were compared. To test the reversibility, ten patients in each group received 30 micrograms/kg neostigmine at 25% recovery of T1. The neuromuscular effects of alcuronium and vecuronium were quantitated by EMG using the DATEX relaxograph. RESULTS. The log-logit analysis of the dose response data revealed an ED50 of 111 micrograms/kg and an ED95 of 250 micrograms/kg, which is in reasonable agreement with the measured effects following 120 micrograms/kg and 210 micrograms/kg alcuronium, resulting in 52 +/- 21% and 96 +/- 4% T1 depression, respectively. The onset time, duration 25%, duration 75% and spontaneous recovery index following 300 micrograms/kg alcuronium (5.0 +/- 3.4 min, 62 +/- 25 min, 119 +/- 38 min and 58 +/- 34 min) appeared to be significantly longer (P less than 0.05) than those observed after 100 micrograms/kg vecuronium (3.2 +/- 1.2 min, 33 +/- 7 min, 49 +/- 9 min and 18 +/- 7 min), respectively. The most striking finding of this study is the enormous individual variations observed in both neuromuscular potency and the time course of action of alcuronium. Following 150 micrograms/kg (routinely employed in daily clinical practice), the magnitude of T1 depression ranged between 19% and 100%. The same vast individual variations were observed in the time course of action following 300 micrograms/kg of alcuronium. The onset time, duration 25%, duration 75% and spontaneous recovery index ranged between 1.3 and 14 min, 22 and 110 min, 93 and 186 min and 32 and 116 min, respectively. CONCLUSIONS. The ED50 and ED95 values for alcuronium found in this study are in the same order of magnitude as 106.8 micrograms/kg and 135 micrograms/kg for ED50 and with 280 micrograms/kg for ED95, respectively, as reported by others. The long duration with slow recovery and the wide individual variation in the neuromuscular effects observed in our study have been reported earlier. Based on the above observations and because of the availability of better alternatives with fewer side effects, we conclude that alcuronium should be added to the list of obsolete neuromuscular blocking agents, together with gallamine and d-tubocurarine.

[Anesthesia for cardioversion. A comparison of propofol and etomidate]

Anaesthesia for elective direct current cardioversion (DCC) was induced with propofol (Diprivan) 1.2 mg/kg in 28 patients and with 0.2 mg/kg etomidate (Hypnomidate) in 20 patients. These mostly high risk patients (NYHA class II to III) were successfully treated with defibrillation. Blood pressure and heart rate were recorded before and after induction and at 2 minutes intervals up to 20 minutes after DCC. Both anaesthetic agents caused mild hypotension. Heart rate did not change significantly after induction but fell significantly after DCC from the mean value of 124 +/- 26 bpm and 122 +/- 37 bpm to 94 +/- 19 bpm and to 91 +/- 19 bpm in propofol and etomidate treated patients respectively. Four patients became apnoeic necessitating assisted ventilation for approximately four minutes. All propofol treated patients had rapid recovery times and opened eyes on command within 5.6 +/- 1.9 minutes after induction, and were fully orientated about 4 minutes later also. Complete amnesia was observed in all patients in this group. In contrast etomidate induced anaesthesia did not cause respiratory depression, but the recovery time was longer. Four patients of this group complained of recall of DCC. In 7 patients due to involuntary movements or myoclonus, after induction with etomidate reliable EKG monitoring appeared to be difficult.

[Nalbuphine as compared with pethidine for postoperative pain therapy]

Nalbuphine is a new partly agonistic antagonistic opioid, that may offer some advantages especially in postoperative pain relief. We compared meperidine (1 mg kg-1) in 100 patients and nalbuphine (0.3 mg kg-1) in 70 patients, administering both agents intravenously after gynaecological operations. Standardised halothane anaesthesia without any opioid was used. After arrival in the recovery room, vigilance (sedation), quality and duration of pain relief were measured by different methods at four different times (0, 15, 30, and 60 minutes). Sedation was significantly more pronounced in the nalbuphine group, but no difference could be found in pain relief and duration between both groups. 6 patients of the n-group showed a short lasting wake-up reaction due to receptor antagonism. 36 patients had to be reinjected at the end of the first hour. We consider nalbuphine to be a safe opioid, however, the marked sedation should be taken into account.

Additional subcutaneous administration of flumazenil does not shorten recovery time after midazolam

We assessed the efficacy of subcutaneous administration of flumazenil (Anexate, Roche), a specific benzodiazepine antagonist, in preventing resedation after initial reversal of midazolam sedation in 30 patients (ASA I-II) undergoing gynaecological surgery. In the post-operative period, the patients received flumazenil i.v. and placebo s.c. (group A), flumazenil i.v. and flumazenil s.c. (group B), or placebo i.v. and placebo s.c. (control group) in a randomized, double-blind procedure. Flumazenil (group A: 0.47 (SD 0.12) mg i.v., group B: 0.48 (0.06) mg i.v.) was significantly more effective than placebo in antagonizing the sedative effects of midazolam, but was accompanied by rebound sedation after 90 min. Additional s.c. administration of flumazenil 0.1 mg (group B) did not eliminate resedation. Undesirable side effects include nausea and vomiting. Local tolerance of the subcutaneous administration of flumazenil was good.

[Neuromuscular blockade using vecuronium in dermatomyositis]

The significant features of neuromuscular blockade with vecuronium in a patient with dermatomyositis are described: vecuronium 0.08 mg/kg resulted in 90%, 0.12 mg/kg in 100% neuromuscular blockade. In contrast to claims made in some previous publications, dermatomyositis did not produce increased sensitivity to vecuronium. Onset time and duration of action were also within normal limits in our patient. Time of spontaneous recovery until antagonism with neostigmine was markedly prolonged, but the dermatomyositis was only one of various possible explanations. Although there are potential hazards in the use of neostigmine in patients with dermatomyositis, antagonism of the neuromuscular block with 2 mg neostigmine was without problems in our patient. Our data support recent suggestions to reconsider the implications of dermatomyositis for anesthesia.

[Severe bacterial infections in gynecology and obstetrics]

Within a 3-years period the presence of nosocomial bacteriaemias was analyzed retrospectively among 13.878 hospitalized patients. The incidence was 0.050%. Antibiotic prophylaxis and the operative technique play an important role in achieving a low incidence of morbidity due to infection. The management of a severe infection includes antibiotic therapy according to culture sensitivity and intensive care.

[The malignant neuroleptic syndrome and malignant hyperthermia]

We report on a patient with neuroleptic malignant syndrome (NMS) caused by a therapy for endogenous depression. The symptoms were hyperpyrexia (39.2 degrees C), rigidity, elevated creatine kinase (CK: 594 U/l) and coma. After transfer from an outside hospital, he was treated, at first without effect with dantrolene p.o. (80 mg q.i.d.) and i.v. (1 mg/kg-1/h-1). Clinical improvement and temperature reduction were noted when the levels of neuroleptic drugs fell during unspecific intensive care with mechanical ventilation, sedation (flunitrazepam, barbiturates), relaxation (pancuronium), and hydration. After uncomplicated weaning from the ventilator the patient became more cooperative and was returned to the psychiatric ward. Further treatment took the form of combined drug therapy with biperiden and flunitrazepam and in addition a series of 12 electroconvulsive therapies (ECT). The elevated CK levels initially decreased, serum potassium levels were found to be within normal limits, and myoglobinuria was not detected during the further course. Trigger agents for NMS are antipsychotic drugs such as thioxanthenes, phenothiazines and butyrophenones. Because the signs and symptoms are so similar to those of malignant hyperthermia (MH), it has been suggested that NMS and MH are related diseases. The postulated mechanisms of NMS become apparent in the CNS, whereas those of MH affect the muscle cell itself. An abnormal in vitro contraction test after NMS should suggest to triggering of MH crisis after succinylcholine administration in anaesthesia for ECT.(ABSTRACT TRUNCATED AT 250 WORDS)

[The lingual thyroid, an unexpected and rare intubation difficulty]

A patient scheduled for a gynecological operation could be intubated only after various repeated attempts. The cause of the airway obstruction was an ectopic thyroid at the right base of the tongue, which made visualization of the glottis impossible. Management and prevention of the unexpected difficult intubation are discussed.

[A fatal paradoxical air embolism during a routine obstetric procedure (cervical cerclage)]

A lethal paradoxical air embolism (PLE) occurred in a 21-year-old secundigravida during general anaesthesia for cervical cerclage on account of cervical insufficiency. The diagnosis of PLE was verified postmortem; we initially diagnosed venous air embolism intraoperatively because of typical symptoms (cyanosis, pulmonary dysfunction, and vascular obstruction) and aspiration of air from the subclavian catheter. We also suspected an arterial embolism due to prominent neurologic deficits. In spite of corrective positioning, controlled ventilation (CPPV and PEEP), volume therapy, and sympathomimetics, resuscitation remained unsuccessful. This very rare complication depends upon several conditions: (1) opened, non-collapsible veins; (2) a pressure gradient from outside to inside the veins; (3) a patent foramen ovale; and (4) a right atrial pressure greater than that on the left, which can cause an air embolism to either the coronary or cerebral circulations. The pathophysiology and causative factors are discussed extensively as the immediately started resuscitation could not alter the lethal course.

Safe use of propofol in a patient with acute intermittent porphyria

On two occasions a patient suffering from acute intermittent porphyria (AIP) was anaesthetized with propofol as the sole agent. The concentrations of urinary porphobilinogen, porphyrins and porphyrin precursors did not exceed preoperative values, and no exacerbation of the disease was noted.