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To determine current clinical neuromuscular use in Morocco anesthetic practice.Clinical practice survey.Anesthesiologists were invited to answer anonymously to question about neuromuscular blocking agents (NMBA): pharmacology, monitoring and antagonism drug use. Corrected yates test was used to compare qualitative parameters and variance analysis for quantitative parameters. P0.05 was considered as significant.We had 171 answers, 54% were paramedics (n=93) and 46% (n=78) were physicians (20% global effective in Morocco). Fifty-five percent were seniors. Vecuronium was the most NMBA used in Morocco for 51% of the anesthesiologists. Mean action time of NMBA was underestimate in more than 60% of the staff questioned specially for seniors (24.6%) than juniors (19.2%). Residual neuromuscular blockade was evaluated only by clinical and spirometric parameters in 72%. TOF monitor was used in 18% more in military hospitals (36%) and insurance clinics (40%) than private hospitals (12.5%). Administration of reversal drugs was systematic in 5.8% of anesthesiologists, frequent for 36.3% and rare for 55%.This study show an underestimation of residual neuromuscular blockade, poor neuromuscular monitor use and lack of knowledge of NMBA specially for senior anesthesiologists and in private hospitals. We should elaborate Moroccan guideline for NMBA use and provide formal training programs for our anesthetic staff.

Sugammadex reverses neuromuscular blockade by chemical encapsulation of nondepolarizing neuromuscular blocking drugs (rocuronium and vecuronium). The imprint of this new molecule has recently been supplemented with a section on haemostasis notifying a longer clotting time without documented clinical consequences. This has resulted in recommendations on the use of sugammadex in the presence of coagulation disorders (pharmacologically-induced or not). The objective of this study was to analyze the experience gathered with this molecule on clinically-evaluated bleeding. No study on this subject is currently available.This is a retrospective study over 1 year between August 2009 and August 2010. All patients with laparotomies for cancer surgery requiring suction drains were included. Patients were allocated to groups according to the type of reversal (without sugammadex versus sugammadex 2 or 4 mg/kg). The endpoint was clinically-evaluated postoperative bleeding (reoperation for haemostasis, blood-stained laparotomy dressings in the post-anaesthesia care unit [PACU], cumulative volume collected in suction drains upon arrival in PACU and then after 2 hours and the next morning at 6a.m).One hundred and ninety-three patients were included in three groups, 78 in the group "without sugammadex", 95 in "sugammadex 2mg/kg" and 20 in "sugammadex 4 mg/kg". There were no reoperations for haemostasis. The comparison among different groups for the endpoint of bleeding showed no significant difference.In this retrospective study performed in patients at high risk of postoperative bleeding, sugammadex at doses of 2 and 4 mg/kg was not associated with increased bleeding. This study, the first in this field, suggests that future prospective investigations should target patients receiving 4 or 16 mg/kg of sugammadex and/or with documented preoperative abnormal coagulations tests.

The launch on the market of a new compound is always an important event for a specialty, particularly when the mechanism of action is completely new. It is the case with sugammadex, a cyclodextrin able to encapsulate specifically and only nondepolarizing steroidal muscles relaxant, rocuronium or vecuronium. The clinical trials which have been performed for sugammadex approval have demonstrated promising results. Sugammadex is able to rapidly reverse (2-5 min) different levels of neuromuscular blockade: moderate (e.g., T2 recovery), deep (e.g., PTC 1-2 recovery) and also few minutes (3-15) after rocuronium administration. Thus, the sugammadex's onset time is about 10 times more rapid than neostigmine without the need of concomitantly atropine administration. Sugammadex has only been tested in small sample size of patients. Therefore, the exact place in the anesthetic practice, the potential indications, the safety profile on a large-scale, thus remain to determine. In particular, how it will modify our current practices characterized to date by 1) under-use of neuromuscular monitoring, 2) a marginal practice of reversal and 3) a wide use of benzylisoquinolines : atracurium and cis-atracurium? Finally, what will be the medical strategies to justify an additional cost when compared to neostigmine?

Sugammadex, a cyclodextrin, is a novel agent designed to encapsulate selectively steroidal neuromuscular blocking agents such as rocuronium and vecuronium as well. One molecule of sugammadex is able to encapsulate only one molecule of muscle relaxant. This original pharmacological property allows a very rapid reversal of muscle paralysis. After sugammadex injection, a train of four ratio higher than 0.9 is obtained in less than 5 minutes in all the patients whatever the degree of muscle paralysis at the time of reversal and even when anesthesia is maintained with halogenated agents. However, in order to preserve this efficacy, the dose of sugammadex needs to be adjusted to the degree of muscle paralysis at the time of reversal : 2 mg/kg after obtaining 2 responses at the adductor pollicis muscle after a train of four stimulation, 4 mg/kg with a post-tetanic count between 1 and 3 responses, and 12 to 16 mg/kg in case of rescue reversal (3 to 15 minutes after 0.6 to 1.2 mg/kg rocuronium). Even if the original property of sugammadex lets us think that per-operative neuromuscular transmission monitoring would not be furthermore useful, the assessment of the exact degree of muscle paralysis before reversal is mandatory for choosing the right dose of sugammadex.

To study accelerographic monitoring of neuromuscular blockade over the vastus medialis muscle in anesthetized patients in the prone position.Sixty adult patients were divided into four groups of 15: prone (P)-post-tetanic count (PTC), P-train-of-four (TOF), supine (S)-PTC or S-TOF group. In the P-PTC and P-TOF groups, the muscular branch of the femoral nerve was stimulated and the movement of the vastus medialis muscle was measured accelerographically. In the S-PTC and S-TOF groups, the depth of neuromuscular blockade was assessed mechanically at the thumb. After administration of vecuronium 0.1 mg.kg(-1), TOF stimuli were delivered every 20 sec in all groups. Onset of neuromuscular blockade (time from vecuronium to the minimum level of T1 (first response of TOF) was compared between the P-PTC or P-TOF group and S-PTC or S-TOF group. Recoveries of PTC and those of TOF were compared between the P-PTC and S-PTC groups and P-TOF and S-TOF groups, respectively.Onset of neuromuscular blockade in the P-PTC or P-TOF group was shorter than in the S-PTC or S-TOF group (132 +/- 43 vs 233 +/- 40 sec, mean +/- SD, P0.001). Recoveries of PTC in the P-PTC and S-PTC groups followed a similar time course. Recoveries of T1/control in the P-TOF and S-TOF groups were also comparable. In contrast, train-of-four ratio (T4/T1, TOFR) in the P-TOF group was higher than in the S-TOF group 60-120 min after vecuronium (P0.05).The degree of neuromuscular blockade can be assessed accelerographically over the vastus medialis muscle even when patients are in the prone position. When evaluated accelerographically over the vastus medialis muscle, onset of neuromuscular blockade is quicker and TOFR is higher than that assessed at the thumb.

Histamine and tryptase, released during anaphylactoid reactions in anaesthesia, can be measured out by radioimmunoassay, provided that their own pharmacokinetic is respected. For two years, we have used sample kits in order to realize the measuring out of these mediators. The aim of this study was to evaluate the interest of these mediators within investigational procedures for anaphylactoid reactions. Eleven anaphylactoid reactions were observed (0,03%). The early blood samples (the first ten minutes following onset of the reaction) were made only in 36% of the cases. Within the serious reactions (grade III), the raising of tryptase indicates the involvement of mast-cell activation. Within minor clinical reactions (grade I), plasma histamine and urinary methylhistamine were the only mediators detected. In an anaphylactic reaction of grade II, which happened after the administering of vecuronium, tryptase was not detected. Therefore, these mediators give the anaesthetists the possibility to prove quickly the severity of the reactions and to direct the investigations very early towards the right way.

A total intravenous technique using propofol, ketamine and vecuronium was successfully used on 29 patients treated for elective surgery at the UNPROFOR French Medical Group (Sarajevo, Bosnia Herzegovina). Operative conditions were satisfactory for the surgeons. Recovery was fast and emergence reactions very limited. No hypoxaemia was observed during the immediate postoperative period. The use of a propofol/ketamine/vecuronium combination is possible in field anaesthesia especially when opiates and inhalational agents are not available.

To assess the neuromuscular blocking effect of vecuronium in adult burn patients, to draw dose-response curves, to determine the ED 95 according to burn surface area, to analyze the time course of this pattern in order to recognize the development of a resistance according to the length of postinjury period.Prospective open study, extending over a 12 month period.Sixty-three consecutive adult burn patients in an acute phase and 13 control patients who had been thermally injured at least 500 days before their inclusion in the study.Anaesthesia was achieved with thiopentone, fentanyl and vecuronium in patients undergoing excision and autograft surgery. Neuromuscular blockade was assessed by thumb adduction, measured by electromyography using evoked train of four responses to ulnar nerve stimulation. Dose-response curves were determined using the single dose method from only one predetermined dose of vecuronium per patient on each day of the study. Dose-response curves were compared using linear regression and ED 95 were calculated from log-probit data.In the control group, ED 95 was 53 mg.kg-1. Before the 7th postinjury day, patients did not differ from controls. Between the 7th and the 70th postinjury day the ED 95 increased significantly. Patients with a burn surface area (BSA) of less than 20% had a ED 95 of 69 mg.kg-1, between 20% and 40% of BSA the ED 95 was 103 mg.kg-1, between 40% and 60% BSA the ED 95 was 134 mg.kg-1 and patients with a BSA over 60% had a ED 95 at 154 mg.kg-1. The onset of action increased in all groups and was significantly different from control group.Acutely burn patients become resistant to the neuromuscular blocking effect of vecuronium. This resistance is related to the magnitude of burn injury. The mechanism of resistance is related to an increase in nicotonic acetylcholine receptors. In these patients, the dose of vecuronium must be titrated to achieve effective muscular paralysis: the correcting factor is 1.3 for a BSA under 20%, 1.9 for a BSA between 20 and 40%, 2.5 for a BSA between 40 and 60%, and 2.9 for a BSA above 60%.

To assess that neuromuscular relaxation onset of the adductor pollicis (AP) is related to neuromuscular stimulation rate. To assess that train-of-four (TOF) at 0.05 Hz is a more accurate indicator of optimal tracheal intubation time and conditions, than TOF at 0.08 Hz.Prospective, comparative, randomized double-blind study.Forty adults, physical class ASA 1 or 2, undergoing general anaesthesia with tracheal intubation were allocated to two groups (n = 20) according to the sequence of stimulation of the AP: either TOF at 0.05 Hz (test group) or TOF at 0.08 Hz (control group).Induction of anaesthesia was achieved with thiopentone, fentanyl and vecuronium (0.1 mg.kg-1). Neuromuscular monitoring was obtained with force displacement transducers attached to each AP. Tracheal intubation was performed once AP muscular response obtained with TOF at 0.05 Hz for test group and TOF at 0.08 Hz for control group was abolished. Results are expressed as mean +/- SEM. Fisher exact test was used for intubation conditions comparison. Curarization time between groups was compared with unpaired Student's t test (P0.05 accepted).TOF with 0.05 Hz stimulation significantly increased curarization time: 217 +/- 7 versus 162 +/- 6 s (P0.001). Intubation conditions were excellent in 95% and good in 5% of patients in the study group, compared to 15 and 40% in the control group, respectively (P0.01) in 45% of the control group patients coughing at intubation occurred.Low stimulation rate (TOF at 0.05 Hz) of AP is a reliable technique to determine the appropriate intubation time for patients paralyzed with vecuronium.

In order to test the hypothesis that under the association propofol-alfentanil-IV lidocaine the trachea could be intubated easily without an additional muscle relaxant, this study compared the intubation conditions when this association was combined or not with vecuronium.Randomized comparative trial.The study included 152 young adults classified as ASA physical class I and Mallampati presentation grade 1, randomly allocated either into Vecu+ group or Vécu0 group, depending on whether vecuronium was co-administered or not.All patients received midazolam 0.05 mg.kg-1 i.v., one minute before induction. Those of group Vecu0 were given successively within two minutes: alfentanil 0.03 mg.kg-1, lidocaine 1.5 mg.kg-1 i.v. and propofol 2.5 mg.kg-1. Patients of group Vecu+ received similar doses of alfentanil and propofol as well as vecuronium 0.08 mg.kg-1. The endotracheal tube was inserted one minute after induction in the patients of Vecu0 group, and after three minutes in those of the Vecu+ group. During intubation, scores of mouth opening, glottis opening and coughing were established, in order to assess intubation conditions.Similar convenient intubating conditions were obtained in both groups (in 97% of patients in Vecu+ group vs 95% of those in Vecu0 group). In the latter, the glottis opening was less pronounced.In young healthy adults, without anaesthetic risk (emergency, full stomach) and without foreseen difficult intubation, the endotracheal tube can be inserted in convenient conditions without a muscle relaxant, under the association propofol-alfentanil-lidocaine iv.

A secondary neuromuscular blockade can occur after transfusion of autologous blood withdrawn after injection of muscle relaxants. In this study time course of muscle relaxation after transfusion of blood withdrawn before or after administration of atracurium (A) or vecuronium (V) was assessed. Forty adults undergoing haemorrhagic urologic surgery were included in the study. After induction of general anaesthesia and intubation of the trachea facilitated by local lidocaine, they were divided into 4 groups. In groups A1 and V1 the blood units were withdrawn before injection of atracurium 0.5 mg.kg-1 or vecuronium 0.1 mg.kg-1. In group A2 and V2 the blood units were withdrawn after administration of muscle relaxants. Haematocrit was decreased to 0.30. The last bolus of these muscle relaxant was injected 30 min before the end of surgical procedure. Autologous blood was transfused when train of four (T4R) recovered to 0.80. Electromyographic elicited responses to T4R stimulation were obtained every minute during the 4 first minutes after the beginning of transfusion (T1 to T4), thereafter every minute during the 5 first minutes after the end of transfusion (T5 to T9), and finally every 5 minutes for 10 minutes (T10 and T11). There was a secondary neuromuscular blockade in patients of groups A2 and V2. The intensity of blockade was more important after vecuronium than after atracurium (p0.01 from T2 to T11 between groups A2 and V2). In group A2, the T4R had not reached the control level at the end of the procedure (0.78 at T11 vs 0.80 at T0). These data emphasize the importance of withdrawing blood units before administration of muscle relaxants.(ABSTRACT TRUNCATED AT 250 WORDS)

Two cases of foetal neuromuscular blockade carried out to obtain foetal immobility during long procedures (in utero foetal exchange transfusion, foetal imaging) are reported. The blockade was carried out in the operating theatre, the mother being awake. Foetal weight had been estimated according to usual echographic parameters. After a long needle had been inserted in the umbilical vein under the guidance of ultrasonography, 0.1 mg.kg-1 vecuronium was injected. Muscle paralysis lasted for about 2 hours in both cases, foetal movements returning spontaneously. There were no side effects due to this technique, a transient foetal bradycardia excepted. Foetal neuromuscular blockade by direct cord injection of muscle relaxants seems to be a simpler, and perhaps safer, technique than obtaining foetal immobility by maternal anaesthesia.

Laparoscopy without an important surgical act was executed in twenty patients. Anaesthetic protocol associated propofol, alfentanil and vecuronium. This protocol meet conditions for ambulatory patients. Only three were not suited to leave hospital six hours after coelioscopy.

From 1974 through 1989, 36 patients with arteriovenous malformations were studied in the neurosurgical department of the Santobono Children's Hospital in Naples; 7 of these patients were younger than three years of age: 5 underwent surgery. The remaining 2 patients presented, respectively, an aneurysm of the vein of Galen and an arteriovenous malformation of the brain stem. Improvements in surgical and anesthesiological techniques allow to treat lesions considered as not amenable to surgery until recent years, with minimal occurrence of preoperative and postoperative complication and a significant amelioration of prognosis.

From 1974 through 1989, 36 patients with arteriovenous malformations were treated in the neuroradiological unit of the Santobono Children's Hospital, in Naples, 7 of these patients were younger than 3 years of age. During such a time-span, dramatic improvements in diagnostic work-up were jelded by introduction of CT-scan and MRI; better angiographic techniques, progress in anaesthesia drugs, equipment and procedures and more rational surgical modalities. Anaesthesia must be tailored in each patient with special consideration of the clinical and neurological conditions of the patients as well of the neuroradiological procedure, specifically, with minimal side effects on cardiovascular and respiratory functions as well on intracranial pressure. The present paper discuss of equipment for cardiovascular assistance and drugs to be employed in the various steps of the diagnostic work-up of such patients.

50 patients selected at random were given vecuronium (group A) or pancuronium bromide (group B) at an initial dose of 0.05 mg X kg-1, followed by repeat injections of 0.0125 mg X kg-1. 34 other patients, separated in two groups: group C (vecuronium) and group D (pancuronium), received stronger doses of both drugs: 0.07 mg X kg-1 initially, followed by 0.022 mg X kg-1 repeat injections. The four groups were anaesthetized according to the same protocol; the patients underwent gastrointestinal and gynaecological surgery, lasting 122 +/- 50 min. The results showed that the time of onset and the duration of action of vecuronium were shorter, and that increasing the dose did not increase significantly the duration of action of these repeat doses: time of onset: 104 +/- 42 s (group A), 205 +/- 36 s (group B), 96 +/- 23 s (group C), 255 +/- 36 s (group D); duration of action: 19 +/- 6 min (group A), 36 +/- 6 min (group B), 24 +/- 7 min (group C), 43 +/- 13 min (group D); mean time between doses: 26 +/- 10 min (group A), 55 +/- 5 min (group B), 33 +/- 7 min (group C), 49 +/- 3 min (group D). The degree of muscle relaxation was always satisfactory in the four groups. Decurarization appeared to be particularly sudden with vecuronium. Neither an abnormally prolonged duration of action, nor any haemodynamic effect, nor any signs of histamine release were seen.

Thirty-six patients undergoing elective surgery were studied after obtaining their informed consent. They were randomly assigned to six series of six patients each. One hour before anaesthesia, all patients received 0.2 mg.kg-1 diazepam orally. After induction of anaesthesia with 1-1.5 mg.kg-1 methohexitone and 5 micrograms.kg-1 fentanyl, the patients were paralysed and ventilation was controlled manually (semi-open circuit; 50% N2O/50% O2). Each patient received a single dose of either 70 micrograms.kg-1 fazadinium, 70 micrograms.kg-1 pancuronium, 2,500 micrograms.kg-1 gallamine or 450 micrograms.kg-1 d-tubocurarine. Neuromuscular function was monitored by measuring the isometric contraction of the adductor pollicis muscle in response to supramaximal stimulations of the ulnar nerve at the wrist (square wave pulse of 0.2 ms duration at supramaximal intensity delivery at 0.1 Hz). Three parameters were measured: the time between the injection of the relaxant drug and recovery of the twitch height at 50% of its baseline (RT0-50); the time between the injection of the relaxant drug and recovery of the twitch height at 90% of its baseline (RT0-90); the time between the injection of the relaxant drug and recovery of the twitch height from 25 to 75% of its baseline (RT25-75). The values of the observed parameters were expressed in minutes (means +/- SEM).(ABSTRACT TRUNCATED AT 250 WORDS)

Different protocols based on the priming principle have been proposed so as to enable rapid tracheal intubation with vecuronium. The conditions of such an intubation have been assessed in 47 ASA I or ASA II patients, with an empty stomach, using a priming dose of 0.01 mg X kg-1, followed by a second injection of 0.1 mg X kg-1 after a short interval of 4 min. An intubation score was defined using a nerve stimulator (Relaxograph Datex), by measuring the twitch in comparison with a reference value, as well as time before intubation for four groups of patients. Good intubation scores with a twitch approaching 50% was obtained in all and, in the same way, for a fifth group of patients, intubated in an arbitrary manner 60 s after the second dose of vecuronium. These results can be compared with those obtained by other authors using a different protocol. Nevertheless, this method does not match perfectly that of suxamethonium. Taking into account the side-effects and above all the inhalation risk existing after a priming dose, is it opportune to use this technique for the anaesthesia of a patient with a full stomach?

The authors describe a technique of vecuronium bromide perfusion at constant flow used to obtain curarisation during 50 renal transplantations. The muscular effects of the drug were monitored through an electromyographical recorder, so as to adjust the perfusion rate. The dose of vecuronium bromide was 47.7 +/- 0.74 micrograms X kg-1 X h-1 (mean +/- SEM), this being lower than the dose recommended by D'Hollander (60 micrograms X kg-1 X h-1) for patients with normal renal function. Furthermore, no recurarisation was observed. Therefore, vecuronium can be considered as a satisfactory muscle relaxant in patients with renal failure, but neuromuscular monitoring appears to be a most important safety factor.

Onset times and conditions of endotracheal intubation were compared in 340 patients. They were all classified ASA I or II and free from any condition which might interfere with the pharmacokinetics or pharmacodynamics of muscle relaxants. The patients were randomly assigned to 4 groups where different muscle relaxation techniques with vecuronium were used: "priming" group (n = 150, 10 micrograms.kg-1 followed by 100 micrograms.kg-1 4 min later), "high dose" group (n = 70, 250 micrograms.kg-1), "control" group (n = 60, 100 micrograms.kg-1) and "succinylcholine" group (n = 60, 1 mg.kg-1). All anaesthetic conditions were otherwise similar. Electromyographic monitoring of the hypothenar muscles displayed no impairment in the reaction to a train-of-four stimulus during the pre-relaxation period (4 min) in the "priming" group. No incident was observed in these patients. Ten % of control response were obtained in 61, 86, 135 and 210 s respectively, whereas maximum muscle blockade was obtained in 97, 174, 314 and 74 s respectively. Intubation scoring showed that optimum conditions were obtained when muscle responses were almost fully abolished. These data are in disagreement with those reports on the priming technique where intubation is carried out 60 s after administration of the relaxing dose.

Twenty-eight ASA I or ASA II adults undergoing microsurgery were anaesthetized according to a standard protocol using droperidol, phenoperidine and thiopentone followed by enflurane. The patients were randomly assigned to two homogeneous groups: the first group (n = 14) received 0.2 mg.kg-1 alcuronium, whereas the second group (n = 14) received 0.08 mg.kg-1 vecuronium. There was no reinjection of either drug and curarization tapered off spontaneously. Neuromuscular monitoring was begun once anaesthesia was stable and after intentional isovolaemic haemodilution. The type of stimulus used was the train-of-four, delivered by a Relaxograph monitor to the ulnar nerve. Muscle response was measured at the hypothenar eminence. The kinetic study considered the time interval required between the injection of the muscle relaxant and the appearance of the minimal value of the twitch (first response of the train-of-four = T1min). The times to recovery of the twitch height to 25, 75 and 100% of the reference value (T1/T0) and of the fourth response of the train-of-four to 25 and 75% of the ratio (T4/T1) were also recorded. Finally, the recovery indexes represented by the times required for T1/T0 and T4/T1 to rise from 25% to 75% respectively were studied. The maximal twitch height inhibition was significantly greater (p less than 0.001) in the vecuronium group (T1min = 0.36 +/- 1.33%) than in the alcuronium group (T1min = 4.36 +/- 5.08%); it occurred significantly more quickly (p less than 0.001) with vecuronium (139 +/- 48 s) than with alcuronium (316 +/- 133 s).(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-response curves have been determined in 37 healthy subjects, after injection of a single bolus of Organon NC 45 (vecuronium or Norcuron). The doses used were 0.0125, 0.025, 0.037 and 0.05 mg X kg-1. The ulnar nerve was stimulated at the wrist and the force of thumb adduction measured. No premedication was used. Anesthesia was induced with thiopentone and fentanyl, and maintained by a nitrous oxide/oxygen mixture under controlled ventilation. PaCO2 was 37 +/- 0.5 mmHg and temperature 36.8 +/- 0.1 degrees C. The effective doses (ED) were: ED50 at 0.024 mg X kg-1, ED90 at 0.034 mg X kg-1 and ED95 at 0.037 mg X kg-1. At 0.05 mg X kg-1, the degree of twitch inhibition was 99.2 +/- 0.6%, the delay of maximum effect was 7.7 +/- 1.4 min, and the length of action (up to 90% recovery) was 27.2 +/- 2.3 min. Vecuronium is therefore a potent neuromuscular blocking agent with a relatively short duration of action.

Pharmacodynamics of vecuronium have been studied in children 1 to 10 years old. Doses from 0.015 to 0.1 mg/kg were given and the effects measured mechanically and by electromyography. For 0.1 mg/kg the pharmacokinetics were established. A smaller distribution volume and higher plasma clearance in children as compared to adults have been found, while the dose-effect ratio is the same. The action of vecuronium is shorter in children than in adults.

115 general and urologic surgery adult patients, ASA class I-II, were divided in four groups according to initial bolus and relaxant used: group A atracurium 0.6 mg X kg-1, group B 0.5 mg X kg-1, group C vecuronium 0.1 mg X kg-1 and group D pancuronium 0.1 mg X kg-1. When the single twitch recovered to 25% of control height (T25), subgroups were individualized depending on whether repeat doses of 1/3 of initial bolus were given or not, and whether reversal was spontaneous or obtained by a standard dose of neostigmine 2.5 mg and atropine 1.25 mg. By ulnar nerve stimulation at the wrist, the force of thumb adduction was recorded on a polygraph; single twitch (tw), train of four (tof) and ratio tof 4/1 (Rtof) were measured. Anaesthesia was induced with thiopentone and fentanyl without premedication and maintained with fentanyl and N2O in oxygen; the trachea was intubated once the block was at its maximum. The onset time of maximal block was 5 min for groups A, B and C, and 7.9 min for group D. T25 was 39.9 +/- 8.5 min for group A, 34.4 +/- 9.7 min for group B, 28.9 +/- 9.9 min for group C and 70.7 +/- 25.9 min for group D. A Rtof equal to 75% was achieved in less than 65 min with atracurium and vecuronium, but much later with pancuronium. Reversal at T25 was efficient, but not really required, for atracurium and vecuronium, but necessary and useful for pancuronium.(ABSTRACT TRUNCATED AT 250 WORDS)

The cardiovascular effects of vecuronium (Organon NC 45 or Norcuron) in man were determined through different protocols using continuous recording of heart rate, arterial blood pressure and parameters obtained by a Swan-Ganz catheter. In healthy anaesthetized patients (n = 23), the effects of a dose of 0.1 mg X kg-1 pancuronium (group A) were compared to those of two doses of vecuronium: 0.1 mg X kg-1 (group B) and 0.3 mg X kg-1 (group C). Pancuronium induced an increase in heart rate (+12%), arterial pressure (+16%) and cardiac index (+8%). No change occurred with vecuronium. In patients under mechanical ventilation in an intensive care unit, we compared the effects of pancuronium 0.1 mg X kg-1 (group D; n = 10), d-tubocurarine (group E; n = 11), vecuronium 0.1 mg X kg-1 (group F; n = 9) and 0.3 mg X kg-1 (group G; n = 10). Pancuronium induced an increase in heart rate (+12%), arterial pressure (+8%) and cardiac index (+9%). d-Tubocurarine induced an increase in heart rate (+6%), a decrease in arterial pressure (-24%) and cardiac index (-17%). No change was observed after vecuronium 0.1 mg X kg-1. After vecuronium 0.3 mg X kg-1, the changes were minimal: a slight decrease in arterial pressure (-5%), a very slight (+3%) and transient (3 min) increase in heart rate were observed. The doses were approximately equipotent in groups A, B and C, whereas the dose of 0.3 mg X kg-1 in group G is about 10 times the 90% effective dose of vecuronium. In geriatric patients with per- or postoperative circulatory deficiency (group H; n = 10, mean age 83 yr), no hemodynamic side effects were observed. Vecuronium seems to be a non-depolarizing neuromuscular blocking agent devoid of cardiovascular side-effects at the generally usual doses.

A case is reported of anaphylactic shock due to vecuronium occurring in a patient who had already had such a shock, due then to pancuronium, during a previous general anaesthesia. The need for a full immuno-allergological investigation, the occasional efficiency of the anti-histamine premedication, and crossed allergies between muscle relaxants are stressed. It is noted that an anaphylactic shock can be seen on first using a new molecule, as the patient can have been sensitized to it by other muscle relaxants. This case was the first to be described of an anaphylactic shock due to vecuronium bromide.

In order to determine if vecuronium can be used for short operations, 40 women were studied during laparoscopy, randomly assigned to four groups: suxamethonium 1 mg X kg-1 in a single bolus followed by an infusion (group A), vecuronium 0.05 mg X kg-1 (group B), vecuronium 0.06 mg X kg-1 (group C) and vecuronium 0.07 mg X kg-1 (group D). Mean duration of operation was 22-25 min. Tracheal intubation can be performed in good conditions in all patients in group A and D, in 5/10 in group B and in 7/10 in group C. During laparoscopy, muscular relaxation was considered excellent in all patients in group A and D, 5/10 sufficient and 5/10 excellent in group C, 5/10 insufficient and 5/10 sufficient in group B. There were 7 reinjections in group B, 2 in group C and 1 in group A. The delay between the end of the procedure and extubation was the same in group A and C (7 min). This delay was significantly higher in group D (9 min). The delay between extubation and positive head lift test was significantly higher in group D. We conclude that the time course of action of vecuronium 0.06 mg X kg-1 is that required for a pelvic laparoscopy of 22-25 min; however, the conditions of intubation are not always perfect. Intubation is easier with a 0.07 mg X kg-1 dose; this dose induces a slight delay for extubation and positive head lift test. In all cases, the patient must be closely watched in a recovery ward.

The authors describe a technique of constant flow perfusion of several anaesthetic drugs, using a simple formula to adjust the perfusion rate to the weight of the patients. Calculation of dilutions is easy: the drug concentration is equal to ten times the rate, per hour and per kg, in practical cases. The flow rate is then a tenth of the patient's weight. This method is easy to apply to several drugs, of which pharmacokinetic parameters justify this administration mode: alfentanil, etomidate, vecuronium bromide... but clinical and instrumental observations should be taken into account for the adjustment of the flow.