Use of atracurium in a patient with plasma cholinesterase deficiency

The use of atracurium during anaesthesia for abdominal hysterectomy in a 37-year-old patient with homozygous plasma cholinesterase [EsEs] deficiency is described. Intubation was achieved utilizing 0.47 mg X kg-1 of atracurium. Subsequent doses of 0.08 mg X kg-1, 0.12 mg X kg-1 and 0.12 mg X kg-1 were given 34, 57 and 78 minutes respectively after the initial dose. At the time of reversal of the residual effects of neuromuscular blockade, 26 minutes after the last dose, spontaneous respiration had resumed. The duration of action of the drug was not different from that described in normal patients. Atracurium would appear to be a safe drug to provide neuromuscular relaxation in patients with plasma cholinesterase deficiency, where surgical procedures of intermediate duration are being undertaken.     

The prolonged use of atracurium in a patient with tetanus

A case of a patient with tetanus is reported in whom an atracurium infusion and artificial ventilation were needed in addition to sedation to control the muscle spasms. The atracurium infusion was used for 71 days, the longest time ever recorded, at a mean rate of 1.3 mg/kg/hour at the end of infusion. The plasma atracurium and laudanosine concentrations were 1.5 micrograms/ml and 0.985 micrograms/ml respectively. Subsequently there was an exponential decline in the serum laudanosine concentration which had decreased to 0.014 micrograms/ml 24 hours later. These results suggest that prolonged use of atracurium by infusion is not associated with excessive cumulation of laudanosine when renal and hepatic function are normal.     

Response to atracurium and mivacurium in a patient with Charcot-Marie-Tooth disease

Purpose

We studied the neuromuscular effects of both atracurium and mivacurium in a patient with Charcot-Marie-Tooth disease (CMTD) during nitrous oxide-oxygen-alfentanil-propofol anaesthesia. Neuromuscular blockade was monitored electromyographically. Train-of-four stimulation (2Hz @ 20 sec intervals) was delivered to the ulnar nerve throughout the period of observation.

Clinical features

A 17-yr-old man with the diagnosis of CMTD was presented twice for two different orthopaedic surgical procedures. The CMTD had been diagnosed since childhood. Neurological examination revealed distal wasting of the upper and lower limbs, generalised absence of reflexes and decreased sensation in a stocking distribution. In both anaesthetics, induction was carried out with alfentanil and propofol, and anaesthesia was maintained with nitrous oxide in oxygen, alfentanil and propofol infusion. The patient demonstrated a normal response to both atracurium and mivacurium. Onset time and the maximum block attained after atracurium and mivacurium were 240 and 210 sec, and 97% and 99% inhibition of T1 (the first twitch of TOF stimulation), respectively. Recovery of T1 to 10% of the control value occurred 30 and 11.5 min after the administration of atracurium and mivacurium, respectively. The patient made uneventful recoveries after both anaesthetics.

Conclusion

There was no evidence of prolonged response to atracurium and mivacurium in our patient with CMTD.     

Cardiac arrest after labetalol and metoclopramide administration in a patient with scleroderma

IMPLICATIONS: Although recent Food and Drug Administration warnings have noted proarrhythmic effects of droperidol, other antiemetic drugs may have similar effects. We report a case of cardiac arrest after uncomplicated regional anesthesia in a patient with scleroderma who received labetalol and metoclopramide after surgery. Metoclopramide should be used with caution when risk factors for dysrhythmia are present.     

The response of a patient with von Recklinghausen's disease to succinylcholine and atracurium

The anesthetic management of a 17-year-old female with von Recklinghausen's disease (multiple neurofibromatosis) is described. Multiple neurofibromatosis is a rare syndrome characterized by abnormal cutaneous pigmentation and numerous skin tumors. In addition to the usual stigmata of the syndrome, patients with neurofibromatosis have been reported to be either sensitive or resistant to succinylcholine. Further, all reports indicate that response to nondepolarizing muscle relaxants is exaggerated. In this patient, the nerve conduction studies were within limit of normal values. During surgery, neuromuscular function was monitored throughout using the train-of-four mechanical twitch response. The response of this patient to succinylcholine was normal and the response to atracurium was slightly prolonged. It is concluded that atracurium offers advantages over the other nondepolarizing muscle relaxants in patients with von Recklinghausen's disease.     

Use of atracurium in continuous intravenous infusion

In this study the use of atracurium was evaluated for use in continuous endovenous infusion by controlling infusion levels using the simple technique of TOF monitoring during general surgical operations. In conclusion, continuous infusion of blocking agents is the preferential technique for controlling and maintaining a neuromuscular block; moreover, the use of besylate of atracurium is advised to ensure a reduced rate of individual variation.     

Curarization of the myasthenia patient by atracurium

The use of atracurium, a new intermediate duration of action non depolarizing muscle relaxant, is described in a myasthenic patient undergoing abdominal surgery. The effective dose to 95% twitch suppression is 0.15 mg.kg-1. Following the first dose, the time from maximum twitch depression to 25% recovery is 32 min, and 33 min following the second dose. The recovery index (25-75% recovery time) and the 5-90% recovery time are respectively 33 and 83 min. The train-of-four ratio is greater than 0.7 within 90 min after the reinjection. The significance of the behaviour of atracurium is discussed. In reduced dosage and with careful neuromuscular monitoring, atracurium appears to be a reasonable and safe choice of myasthenic patients to provide surgical relaxation.     

Inadvertent intrathecal injection of labetalol in a patient undergoing post-partum tubal ligation

After receiving a continuous spinal anesthetic for labor following an inadvertent dural puncture with a 17-gauge epidural needle, a morbidly obese parturient underwent post-partum tubal ligation 12 h after vaginal delivery. The patient received a total of 2 mL of 0.75% hyperbaric bupivacaine for the surgery. In response to moderate hypertension the patient received intravenous labetalol hydrochloride 20 mg. She subsequently was inadvertently administered approximately 15 mg of labetalol through the spinal catheter. The spinal catheter was removed immediately after the procedure. She suffered no apparent adverse neurologic effects.     

Pharmacodynamics of vecuronium and atracurium in the obese surgical patient

The effect of obesity on the duration of action of the nondepolarizing muscle relaxants atracurium and vecuronium was studied in 28 neurosurgical patients. In obese patients given vecuronium (0.1 mg/kg), the time to go from 5 to 25% of recovery of twitch response was statistically significantly longer (14.6 +/- 7 minutes, mean +/- SD) than it was in nonobese control patients (6.9 +/- 2 minutes). Similarly, with vecuronium times for recovery from 25 to 75% were longer (33 +/- 15 minutes) in obese patients than in control patients (13.2 +/- 2 minutes), as was time to 75% recovery, 82 +/- 30 minutes in obese patients, 50 +/- 9 minutes in controls. In contrast, obese patients given atracurium (0.5 mg/kg) exhibited no difference in recovery indexes or recovery times when compared to control patients of normal weight. The prolonged duration of action of vecuronium in obese patients is most likely related to impaired hepatic clearance and/or an overdose effect with recovery occurring during the distribution phase. That the duration of action of atracurium is not prolonged in the obese is believed due to this relaxant's not depending on organ function for elimination.     

Case report: Profound hypotension associated with labetalol therapy in a patient with cerebral aneurysms and subarachnoid hemorrhage

PURPOSE: Labetalol is an effective antihypertensive medication frequently used to treat systemic hypertension in acute care settings, including the management of hypertension associated with a subarachnoid hemorrhage. We present a case of profound hypotension, refractory to inotropic and vasopressor therapy following an iv infusion of labetalol. CLINICAL FEATURES: Initiation of an iv labetalol infusion resulted in good blood pressure control in a patient suffering from a Fisher grade 3 subarachnoid hemorrhage with an initial Glascow coma scale of 14/15 and mild hydrocephalus. Progressive deterioration of neurological symptoms and evidence of worsening hydrocephalus preceded the sudden development of profound hypotension (60/35 mmHg) and bradycardia with a minimum heart rate of 40 beats.min(-1). Initial resuscitative efforts included administration of intravascular fluid, hypertonic saline, atropine, adrenalin (more than 10 mg in divided doses) and noradrenalin. These measures restored the blood pressure to 80/45 with a HR of 98 beats.min(-1). Intraoperative placement of an intraventricular drain released cerebrospinal fluid under pressure with an initial intracranial pressure of 15 cm H(2)O. A combination of adrenalin, noradrenalin, dopamine and vasopressin infusions were required to restore the blood pressure to 130/65 mmHg after an additional two hours. All inotropic and vasopressor support was weaned off after the 14th hr (about two drug half-lives). The patient was awake and responsive the following day, with no obvious neurological consequences. No evidence of neurological injury, drug administration error or myocardial dysfunction was documented. CONCLUSION: The episode of profound hypotension which occurred after initiating a labetolol infusion required maximal combined vasopressor therapy to restore the blood pressure suggesting that this patient demonstrated an extreme sensitivity to labetalol. Combination therapy with adrenergic and nonadrenergic agonists may be required for optimal treatment of profound hypotension associated with labetalol-induced vasoplegia.     

Use of labetalol during anesthesia for pheochromocytoma removal

Labetalol, an alpha and beta adrenergic blocking drug, was used during anesthesia for removal of a very large pheochromocytoma which was predominantly epinephrine secreting. The 70-year-old female patient suffered from angina pectoris and chronic bronchitis. A preoperative treatment including an alpha-adrenolytic drug was administered but beta-adrenergic blockers were avoided because of the risk of cardiac decompensation and bronchoconstriction. During the operation, hypertensive peaks were easily controlled by bolus injections of labetalol 20 mg. The removal of the tumor was followed by a transient moderate hypotension. Heart rate remained stable throughout the operation. No hemodynamic problems occurred during the postoperative period. With regard to this case, a summary of the literature concerning the properties of labetalol is presented.     

Use of StyletScope in a patient with airway injury

A forty-year old man hanged himself and was transported to our hospital. On arrival his consciousness was clear but he showed dyspnea, dysphagia, and oral bleeding. Tracheal intubation was attempted but was failed and emergency tracheostomy was successfully accomplished. Tracheoplasty was soon scheduled under general anesthesia because of subcutaneous emphysema. An ordinary laryngoscope could not give a view of the larynx at all. Orotracheal intubation was accomplished with StyletScope. It worked very well for the destroyed trachea. StyletScope is a useful device for intubation, especially in difficult airway management.     

Priming with atracurium

Priming with atracurium was evaluated by dividing 39 patients into 2 groups. All received 0.2 mg IV glycopyrrolate and fentanyl, 50 micrograms IV. Group 1 received saline, group 2 received 0.06 mg/kg atracurium and a stop watch was started. After 3.5 min the patients were asked to lift their heads and maximum negative inspiratory pressure (MIP) was measured. Anesthesia then commenced with thiopental and a twitch monitor was applied to the ulnar nerve. At 5 min group 1 received 0.36 mg/kg atracurium and group 2 was given 0.30 mg/kg atracurium. At 6.5 min intubation was accomplished in all but one patient in group 1 and all but one in group 2. Mean T4/T1 ratios at 90 sec were 0.73 in group 1 and 0.51 in group 2. This difference was statistically significant (P less than 0.001). Bucking on the endotracheal tube occurred in 72% of patients in group 1 and 62% of those in group 2 (not significant). Intubating conditions were "excellent" in 56% of those in group 1 and 75% in group 2 (not significant). "Good" conditions were seen in 33% of group 1 and 15% of group 2 patients (not significant). "Fair" conditions were noted in 6% of patients in group 1 and 5% of group 2 patients (not significant). The time to maximum twitch depression was 11.3 min and 11.5 min in groups 1 and 2 respectively (not significant). All patients in group 1 could sustain head lift whereas four patients in group 2 could not (not significant).(ABSTRACT TRUNCATED AT 250 WORDS)