Haemodynamic differences between pancuronium and vecuronium in an experimental pig model.

OBJECTIVE: To compare baseline cardiovascular function in anesthetised pigs using either pancuronium or vecuronium as a neuromuscular blocker. STUDY DESIGN: Retrospective, non-randomized comparison. ANIMALS: Norwegian Land Race pigs (Sus scrofa domesticus) weighing mean 42 ± SD 3 kg. METHODS: One hundred and sixteen animals from four different research protocols premedicated with identical doses of ketamine, diazepam, atropine and isoflurane, and anaesthetised with pentobarbital, fentanyl, midazolam and N(2)O were arranged into three uniform groups with respect to neuromuscular blocking agent: pancuronium bolus of 0.063 mg kg(-1) followed by 0.14 mg kg(-1) hour(-1) (n = 54), low-dose vecuronium 0.4 mg kg(-1) /0.2 mg kg(-1) hour(-1) (n = 29) and high-dose vecuronium 0.6 mg kg(-1) /0.3 mg kg(-1) hour(-1) (n = 33). RESULTS: The majority of cardiovascular parameters demonstrated no significant differences between groups. For heart rate, there was an overall group difference, p = 0.036. Dromotropy was low in the pancuronium group, with an increased normalised PR-interval compared to the high-dose vecuronium group, median 0.200 interquartile range (0.190, 0.215) versus 0.182 (0.166, 0.199), p < 0.05. Left ventricular compliance was increased in pancuronium-treated animals, demonstrated as a reduction in the nonlinear end-diastolic pressure volume relationship ß compared to both vecuronium groups, 0.021 (0.016, 0.025) versus 0.031 (0.025, 0.046) and 0.031 (0.022, 0.048), p < 0.05. The linear end-diastolic pressure volume relationship EDPVR(lin) was reduced as well in the pancuronium group, compared to the low-dose vecuronium group, 0.131 (0.116, 0.169) versus 0.181 (0.148, 0.247), p < 0.05. CONCLUSIONS: There are only minor haemodynamic differences when using pancuronium compared to vecuronium in the fentanyl-pentobarbital-midazolam-N(2)O anesthetised domestic pigs. Furthermore, increasing doses of vecuronium have minimal haemodynamic effects. CLINICAL RELEVANCE: Experimental studies in pigs using either pancuronium or vecuronium as a neuromuscular blocking agent are comparable with regard to cardiac and haemodynamic performance.

Pancuronium dose refinement in experimental pigs used in cardiovascular research.

OBJECTIVE: To quantify the dose of pancuronium required to obtain moderate neuromuscular blockade as monitored by acceleromyography (NMB(mod) : train-of-four count of ≤2) as a part of a balanced anaesthetic protocol in pigs used in cardiovascular research. STUDY DESIGN: Prospective cross-sectional study. ANIMALS: Five pigs (median body weight: 60 (range 60-63) kg). METHODS: Anaesthesia was induced with xylazine, ketamine, atropine and midazolam and maintained with isoflurane in O(2) :air and fentanyl. Pigs received 0.1 mg kg(-1) pancuronium initial bolus to reach NMB(mod) followed by 0.1 mg kg(-1) hour(-1) constant rate infusion (CRI). During anaesthesia a twitch count of 3 or measureable T4/T1 ratio indicated unsatisfactory NMB. In this case additional 0.4 mg boluses of pancuronium were administered IV to effect in addition to the CRI. Descriptive statistical analysis was performed to express the median and range of the bolus and CRI dose of pancuronium in pigs. Cardiovascular parameters were analyzed at selected time points with Friedman Repeated Measures Analysis on Ranks. Spearman Rank test was used to evaluate correlation between parameters. RESULTS: Acceleromyographic monitoring of NMB is feasible in anaesthetized pigs. The median initial dose and rate of pancuronium required to achieve NMB(mod) were 0.10 (range 0.10-0.13) mg kg(-1) and 0.11 (range 0.10-0.21) mg kg(-1) hour(-1) , respectively. The administration rate showed considerable individual variation. CONCLUSIONS AND CLINICAL RELEVANCE: These pancuronium doses can be used as a guideline to achieve NMB(mod) in pigs as part of a balanced anaesthetic protocol. Instrumental NMB monitoring is essential because of individual kinetic variations and compliance to monitoring guidelines.

The medical-legal quandary of healthcare in capital punishment: an ethical dilemma for the anesthesia provider.

The case of Brase v Rees was presented before the US Supreme Court to consider the constitutionality of death by lethal injection as practiced in the state of Kentucky. The 3-drug combination of sodium thiopental, pancuronium bromide, and potassium chloride is a key aspect in question. Capital punishment conflicts with medical and nursing code of ethics preventing providers who are skilled at difficult intravenous (IV) access, assessment of appropriate sedation, and involvement without fear of disciplinary action. Therefore, untrained or undertrained personnel from the prison have been delegated these duties. Cases in which failure to establish or maintain IV access has led to executions lasting up to 90 minutes before the execution was complete. Participation by skilled medical personnel has been a debate between the medical and legal communities since the inception of lethal injection. Healthcare should reevaluate the ethical and moral principle of beneficence as the legal system attempts to evaluate the constitutionality of lethal injection. Can a nurse or doctor step out of the role of medical professional, use knowledge and skill to make death by lethal injection more humane, and not violate the ethical principle of "do no harm"?

Fuzzy logic for model adaptation of a pharmacokinetic-based closed loop delivery system for pancuronium.

In this paper, we investigate the ability of fuzzy to adapt the parameters of a pharmacokinetic and pharmacodynamic model-based controller for the delivery of the muscle relaxant pancuronium. The system uses the model to control the rate of drug delivery and uses feedback from a sensor which measures muscle relaxation level to adapt the model using fuzzy logic. The control strategy administers mini-bolus doses of pancuronium and modulates the magnitude and time interval between the bolus doses to maintain a patient's muscle relaxation within an allowable range specified by the user. Before each new dose is given, the fuzzy logic adaptation scheme uses the error between the predicted patient response and the measured response to adapt the model. The system was tested using computer simulation by varying the parameters of the model by 50% from their nominal values. It was also evaluated in a clinical trial of five patients undergoing surgical procedures lasting 5 h or longer.

Economic considerations in the use of neuromuscular blocking drugs.

The acceptance of new and increasingly expensive technologies is a major component of the rising costs of health care. While the practice of anesthesia has been relatively immune from the effects of cost containment, it is inevitable that practitioners will have to justify costly practices. Available pharmacoeconomic methods can be applied to the use of all anesthetic drugs, particularly neuromuscular blocking drugs. Cost-effectiveness analysis allows the practicing anesthesiologist to prioritize the use of neuromuscular blocking drugs to maximize their benefit while reducing unnecessary costs.

[Relaxation and the electromyographic identification of the recurrent laryngeal nerve]. / Relaxierung und elektromyographische Identifikation des N. laryngeus recurrens.

INTRODUCTION: Electromyography for the identification of the recurrent laryngeal nerve is gaining ever more acceptance in thyroid surgery. Relaxation of the patient, e.g., to improve intubation conditions for anesthesia, carries a potential risk for error. METHOD: After definite identification of the recurrent laryngeal nerve and the vagus nerve (Neurosign 100, Magstim Co., Wales), ten consecutive patients were relaxed with mivacurium and atracurium besylate at a weight-dependent ED95 dosage. After peripheral relaxation was achieved (TOF-Watch, Organon Teknika Corp., at the adductor muscle of the thumb), the signal derived via the vocal muscle was assessed acoustically in 3-min intervals by the surgeon and graphically recorded by computer (EWACS, Inomed Co.). RESULTS: Complete peripheral relaxation was attained with mivacurium after 3-7 min and with atracurium after 7-11 min. A decrease in amplitude of the vocal muscle signal of >60% was recognized by the surgeon as a weakened signal and could be confirmed during an average duration of 13.3 min with mivacurium (maximum: 37 min) and 17.7 min with atracurium besylate (maximum: 23 min), respectively. Complete obliteration of the acoustic signal (<20% of the initial signal) occurred in three of six patients treated with mivacurium and in four of four patients treated with atracurium. CONCLUSIONS: The accuracy of electromyography of the recurrent laryngeal nerve can be substantially impaired by the administration of relaxants. If this medication cannot be dispensed with, the surgeon must be aware of the situation. In these cases, a peripheral relaxometer should also be employed to monitor relaxation as it subsides.

Slow EEG-power spectra correlate with haemodynamic changes during laryngoscopy and intubation following induction with fentanyl or sufentanil.

We studied nociception-associated arousal following laryngoscopy and intubation in patients scheduled for elective open heart surgery, using EEG power spectra and hemodynamics. Either fentanyl (7 micrograms/kg; n = 30) or sufentanil (1 microgram/kg; n = 30) were given in a randomized fashion to induce anesthesia in heavily premedicated patients, followed by pancuronium bromide (100 micrograms/kg). EEG-power spectra (delta, theta, alpha, beta) as well as mean arterial blood pressure (MAP) and heart rate (HF) were measured at the following end-points: before the induction of anesthesia (control), 1 and 10 minutes after laryngoscopy and intubation (L & I). Linear regression analysis was computed to determine which of the EEG power spectra was most sensitive to detect insufficient blockade of nociceptive-related arousal when correlated with haemodynamics. In the fentanyl group the change in HF closely correlated with the decrease of power in the slow delta- and theta-domain (r2 = 0.98 and r2 = 0.89 respectively) of the EEG. The change in MAP also closely correlated with a decrease in the slow delta- and theta-domain (r2 = 0.97 and r2 = 0.99 respectively). There was little correlation in regard to spectral edge frequency (SEF) and HF and MAP changes (r2 = 0.36 and r2 = 0.12 respectively). In the sufentanil group the change in HF correlated closely with an increase of power in the fast alpha and a decrease in the slow theta-domain (r2 = 0.91 and r2 = 0.98 respectively) of the EEG. The changes in MAP closely correlated with an increase in the fast alpha-band a decrease in the slow theta-domain (r2 = 0.98 and r2 = 0.73 respectively). Also there was little correlation of SEF with HF and MAP changes (r2 = 0.09 and r2 = 0.02 respectively). Among the EEG-spectra, reduction of power in the slow delta- and theta-bands are the most sensitive parameters to determine insufficient antinociception of opioids commonly used for the induction in cardiac anesthesia. Increase of power in the alpha-band seems to be closely correlated with cortical reactivation and reduction of hypnosis, while a reduction of power especially in the deltabut more so in the theta-band of the EEG reflects nociception related arousal.

[Tetraparesis in an infant after prolonged administration of pancuronium]. / Tétraparésie chez un nourrisson après administration prolongée de pancuronium.

Long-term administration of pancuronium for ventilatory support of adults with ARDS may result in severe tetraparesis, with areflexia and atrophy of distal muscles. This adverse effect occurs rarely in paediatric intensive care units. We describe a case of tetraparesis after prolonged pancuronium infusion in a 9-month-old girl who experienced a severe bronchopneumonia caused by para-influenza virus, requiring endotracheal intubation and mechanical ventilation. To decrease chest wall rigidity, pancuronium was administered over 11 days, with a total dose of approximately 120 mg of pancuronium bromide. The day after discontinuation of the muscle relaxant she had a severe tetraplegia with areflexia, but normal head movements. Electromyography showed a normal neuromuscular transmission. She recovered from tetraplegia three months later. Other causes of peripheral neuropathy were eliminated. Electroencephalograms and head CT-scans were normal. The recovery pattern observed in our patient corresponded to the process of regeneration seen after axonal degeneration. It is suggested that these neuromuscular complications were caused by prolonged high-dosage pancuronium treatment, associated with corticosteroid and aminoglycoside administration.

[Clinical use in adults of 2 new muscle relaxants: atracurium and vecuronium]. / Utilisation clinique chez l'adulte de deux nouveaux myorelaxants: l'atracurium et le vécuronium.

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)

[Comparative study of ORG NC 45 and pancuronium during anesthesia]. / Etude comparative de l'ORG NC 45 et du pancuronium en pratique anesthésique.

The muscle relaxant effects of ORG NC 45 and pancuronium were compared in anesthetized patients with normal liver and renal functions. In all patients, the muscle relaxant effect was monitored by measuring the strength of the adductor pollicis muscle elicited by supramaximal stimulation of the ulnar nerve at the wrist. Different modes of administration of the muscle relaxants were used. In order to facilitate tracheal intubation, a dose of 100 mu X kg-1 of ORG NC 45 or pancuronium was administered. This dose was followed or not according to the type of surgery by repeated doses of 25 micrograms X kg-1. The results of this study indicate that ORG NC 45 is much shorter acting than pancuronium, and non cumulative. The dose of 100 micrograms X kg-1 produced adequate conditions for tracheal intubation 3 to 4 min after the administration of the muscle relaxant. The recovery of the muscle strength to 75% of control value was achieved 46 min and 100 min after a single dose of 100 micrograms X kg-1 of ORG NC 45 and pancuronium respectively. The interval of time between repeat injections averaged 20 min for ORG NC 45 and 40 min for pancuronium.

[Clinical use of vecuronium during celioscopy]. / Utilisation clinique du vécuronium au cours des coelioscopies.

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.

[Clinical research of muscular relaxation induced by alcuronium and pancuronium].

The clinical experiment was designed for observing effect of muscular relaxation induced by alcuronium and pancuronium. 40 patients were randomly divided into alcuronium group (A) and Pancuronium group (P). A group and P group were redivided into A1,A2 groups and P1,P2 groups according to differences of the initial doses of muscle relaxants. The results of neuromuscular monitoring indicate that onset time and main-tenance time of 0.3 mg/kg alcuronium were respectively 2.4 min and 63 min; 0.1 mg/kg pancuronium were 2.7 min and 70 min. The initial doses mentioned above are suitable to intubation of anesthesia and meet surgical need for muscular relaxation. The changes of MAP,HR,blood kalium and natrium were not evident in statistical significance before and after administration of relaxants.

[Respiratory muscle weakness after prolonged use of hydrocortisone and pancuronium bromide].

A 30-year-old man was admitted because of status asthmaticus. He required 7 days of artificial ventilation and was treated with hydrocortisone 1.2 g.day-1 and bronchodilaters. Pancuronium bromide 0.08 mg.kg-1.hr-1 was given for 64 hours for the ease of artificial ventilation. On day 3, severely elevated airway pressure resulted in left pneumothorax and isoflurane 1% was given for the following 2 days. Respiratory muscle weakness was evident 24 hours after discontinuation of pancuronium infusion on day 5 while full 4 twitches of TOF on the adductor pollicis muscle were seen at the time. The respiratory muscle weakness continued for another 3 days and he was extubated on day 8. Serum creatine kinase concentration rose to 2178 U.l-1 on day 6 and returned to normal on day 11. Hematurea, hyperpyrexia and metabolic acidosis were never seen during the course. Acute corticosteroid myopathy was suspected to be the cause of the prolonged respiratory muscle weakness.

Method of intraoperative monitoring of neuromuscular function and residual blockade in the recovery room.

We evaluated the method used intraoperatively to assess the degree of neuromuscular blockade prior to pharmacologic reversal to determine its role in preventing residual blockade in the postanesthesia care unit (PACU). We studied 38 patients who received a nondepolarizing muscle relaxant during general anesthesia for carotid endarterectomy or thoracotomy. The anesthesiologist assessed the degree of neuromuscular blockade intraoperatively prior to pharmacologic reversal either by the standard method of visually counting the number of evoked thumb twitches elicited by supramaximal train-of-four stimulation of the ulnar nerve (i.e., thumb train-of-four count), or by an alternative method such as 1) visually counting the number of evoked orbicularis oculi muscle twitches elicited by supramaximal train-of-four stimulation of the facial nerve, or 2) observing the patient for clinical evidence of partial recovery (e.g., swallowing or attempts to breathe). Residual blockade in the PACU was defined as 1) a train-of-four ratio less than 0.70 (measured by a mechanomyograph), or 2) the inability of the patient to perform clinical tests of neuromuscular function (e.g., a sustained head lift for 5 seconds) and evidence of neuromuscular weakness that was resolved following administration of edrophonium. Five of the 22 patients (23%) in whom one of the alternative methods was used had residual blockade in the PACU; none of the 16 patients with a thumb train-of-four count of 3 or 4 before pharmacologic reversal of NMB had residual blockade in the PACU (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[The characteristics of the action of nondepolarizing myorelaxants during operations on children with thermal injuries]. / Osobennosti deistviia nedepoliarizuiushchikh miorelaksantov vo vremia operatsii u detei s termicheskoi travmoi.

Effects of nondepolarizing myorelaxants pancuronium, arduan, and tracrium were studied during surgery in 347 children with thermal injuries aged from several months to 15 years. Nondepolarizing myorelaxants are drugs of choice for providing myoplegia in children operated on for thermal injuries. The optimal initial dose of these agents in children with burns is 30-50% higher than the recommended dose and depends on the size of the lesion. For controllable myoplegia, the doses of subsequent injections are to be 1.-5-2 times lowered in comparison with the initial dose. The effects of pancuronium and arduan depend on the hepatorenal function. Tracrium ensures sufficient controllable myorelaxation in children with burns even in cases with hepatorenal dysfunction.

[Rocuronium (esmerone) in anesthesia during surgery under extracorporeal circulation]. / Rokuronium (ésmeron) pri anesteziologicheskom obespechenii operatsii s iskusstvennym krovoobrashcheniem.

The study was undertaken to examine the myoplegic, hemodynamic, and histamine-releasing effects of the new aminosteroidal myorelaxant Rocuronium (esmerone, Organon firm) used to maintain anesthesia in cardiac surgical patients by orienting to early tracheal extubation. Twenty two patients aged 50 +/- 3 years operated on under extracorporeal circulation were examined. At the initial stage of maintenance, the agent in a dose of 0.6 mg/kg failed to affect cardiac pump function and to elevate plasma histamine levels. A moderate vagolytic effect was shown in 45% of cases. The incidence of myoplegia reduced in patients with significant circulatory insufficiency. In the preperfusion period, Rocuronium in a dose of 10.2 +/- 0.9 micrograms/kg/min blocked neuromuscular conduction (NMC) at a level of 5.1 +/- 1.8 to 19.2 +/- 3.5%. During hypothermic extracorporeal circulation and postperfusion period, the dosage of the myorelaxant substantially decreased. After termination of Rocuronium infusion, the time of up to 95%-recovery of NMC was 63 +/- 6 min. Early tracheal extubation was conducted in 68% of the patients 69 +/- 7.6 min after the end of the operation. Residual myoplegia was absent. The predictable recovery of NMC following the use of Rocuronium creates conditions for early activation of patients operated on under extracorporeal circulation.

[Clinical, neurophysiological and hemodynamic effects of a new nondepolarizing myorelaxant mivacurium in heart surgery patients]. / Klinicheskie, neirofiziologicheskie i gemodinamicheskie éffekty novogo nedepoliarizuiushchego miorelaksanta mivakuriuma u kardiokhirurgicheskikh bol'nykh.

Thirty patients aged 23 to 65 years with ASA class III operated on the heart under total intravenous anesthesia were examined after the Good Clinical Practice protocol. Mivacurium in bolus dose of 0.2 mg/kg was injected for intubation of the trachea; neuromuscular blocking (NMB) was maintained by a repeated injection of the drug in a dose of 0.15 mg/kg, after which it was infused at a rate of 1 to 10 micrograms/kg/min. Accelerometric control of neuromuscular conduction was carried out by the Organon (Belgium) TOF-Guard device. Central and peripheral hemodynamics was monitored. Side effects of the drug were recorded. Bolus injection of mivacurium in a dose of 0.2 mg/kg caused T1 suppression (90%) after 2.6 +/- 0.7 min. Maximal (97.7 +/- 4.5%) suppression was observed after 4.17 +/- 2.5 min. The conditions of intubation of the trachea after 3.9 +/- 1.8 min in the presence of 78 to 100% T1 suppression (97.7 +/- 4.5%) were considered excellent or good in 96.6% of cases. Clinically and neurophysiologically sufficient muscle relaxation after the first injection of the drug persisted for 27.7 +/- 7.3 min. Minimal rate of infusion for maintaining the NMB at 95 +/- 4% level of T1 suppression was 6.3 +/- 1.7 micrograms/kg/min. Bolus injection of mivacurium in a dose of 0.2 mg/kg for 60 sec involved a 1-3-min drop of the mean arterial pressure by 10.5% and a 10.3% decrease of heart rate. Repeated bolus injection of the drug in a dose of 0.15 mg/kg and its infusion did not change the peripheral and central hemodynamics. The most typical side effect of the drug in a dose of 0.2 mg/kg is short-term reversible reddening of the skin of the face and neck, observed in 20% of patients. The results permit us to consider mivacurium as an effective, safe, and controllable agent, which can be used in cardiosurgical patients.

[Pharmacokinetics and pharmacodynamics of vecuronium in children]. / Pharmacocinétique et pharmacodynamique du vécuronium chez l'enfant.

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.

Medication errors in anaesthetic practice: a report of two cases and review of the literature.

BACKGROUND: Mistakes in the identification and administration of drugs may be fatal. This is especially so in the practice of anaesthesia. This is a report of 2 cases of near fatality due to mistakes in drug administration from look-alike medications. OBJECTIVE: To highlight the significance of medication errors in our practice and to discuss the best methods of prevention. METHOD: A report of two cases of errors in the administration of drugs during the conduct of anaesthesia. The subsequent management of the cases is presented, and the findings from the literature are discussed. RESULT: In case 1, an adult male presented for herniorrhaphy and after induction with propofol 1mg/kg intravenously, Pancuronium bromide injection 4 mg was administered intravenously, in the place of suxamethonium chloride injection. In case 2, For induction of anaesthesia, 100mg of thiopentone sodium was administered in place of 25mg of the same drug because Thiopentone 1 gm vial was mistaken for Thiopentone 500 mg vial in a 2 year old girl. In both cases, the errors were detected early and there were no adverse sequelae. CONCLUSION: Medication errors are a potential source of iatrogenic harm to patients undergoing anaesthesia. Strict adherence to principles as well as constant vigilance would minimize this problem.