J.M. Hunter

Atracurium infusions in patients with renal failure on an ITU.

An infusion of atracurium was used (after an initial bolus dose) in five patients with renal and respiratory failure, who were being subjected to intermittent positive pressure ventilation before renal dialysis. Neuro‐muscular function was monitored by the train‐of‐four pattern of stimulation. In three patients, atracurium 0.6–0.7 mg/kg/hour completely abolished the twitch response; in the other two (both of whom were markedly oedematous) this did not occur, even with a dose of 1.0 mg/kg/hour. although satisfactory clinical control was obtained. In all patients. there was rapid spontaneous recovery when the infusion was stopped. One patient convulsed, but plasma laudanosine levels taken at this time were below the toxic range. Atracurium infusions appear to provide easily controllable neuromuscular blockade in the intensive therapy unit, although these preliminary results suggest that larger doses may be required in the oedematous patient.

Vecuronium infusions in patients with renal failure in an ITU

The use of an infusion of vecuronium is described in seven patients with renal and respiratory failure in an intensive therapy unit. Neuromuscular function was monitored throughout using the train‐of‐four twitch technique. A bolus dose of vecuronium (0.1 mg/kg) was given, followed immediately by a continuous infusion (0.05 mg/kg/hour). The infusion rate was adjusted until the first twitch of the train was helow 20% of control and then run at a constant rate.

Vecuronium in the myasthenic patient

The use of vecuronium in six patients with myasthenia gravis undergoing thymectomy is described; the train‐of‐four twitch technique was used to monitor neuromuscular function. The first two patients received an initial dose of 0.02 mg/kg and incremental doses of 4 μg/kg, which is in the order of one fifth of that normally used. Satisfactory depression of the first twitch of the train‐of‐four, however, was not obtained and, therefore, in the remaining four patients the doses were doubled. At this dose satisfactory depression of the first twitch was achieved. Neostigmine 5.0 mg produced adequate reversal of residual neuromuscular blockade and the train‐of‐four twitch response recovered to normal levels. With reduced dosage and with careful neuromuscular monitoring. vecuronium can be used safely in the myasthenic patient.

Ethylene glycol poisoning. A case report.

A case of self‐poisoning with ethylene glycol is presented. The metabolic upset induced by ingestion of this substance is discussed and the principles underlying treatment with ethyl alcohol, sodium bicarbonate and renal dialysis are outlined. The practical problems experienced with this therapy are detailed. The need for immediate instigation of treatment and for intensive care are emphasised.

An assessment of the Cerebrotrac 2500 for continuous monitoring of cerebral function in the intensive care unit.

Experience of the use of the Cerebrotrac 2500 EEG monitor in 17 patients subjected to artificial ventilation in an intensive care unit is reported; seven were receiving continuous sedation with morphine, midazolam and propofol singly or in combination and 10 received both sedation and the neuromuscular blocking agent, atracurium. The processed EEG patterns could not be precisely correlated with a standard clinical scoring system but were useful in determining the adequacy of sedation, particularly when a muscle relaxant was used. The monitor also shows considerable promise in the management of the paralysed patient with widespread convulsive activity in whom ischaemic brain damage may be occurring from epileptiform activity in the absence of any clinical manifestation. The ability to detect cerebral irritability or isolated epileptiform discharges using this apparatus is, however, questionable. The equipment was easy to use and robust; the running costs were 9.5p per hour.

Synergism between halothane and labetalol

A patient in chronic renal failure, who was receiving large doses of the combined alpha- and beta-blocking agent, labetalol, was selected for renal transplantation. A low concentration of halothane was used for induction and maintenance of anaesthesia, but severe myocardial depression occurred which proved unresponsive to atropine or isoprenaline, although it responded to a dopamine infusion. Synergism has already been reported between labetalol and high concentrations of halothane, but this case suggests that, in patients with previous myocardial damage, much lower concentrations of this inhalational agent may prove fatal.

The pharmacodynamics of alcuronium in the elderly

Alcuronium (0.2 mg/kg) was given to 12 elderly patients, mean age 77 years (range 70–88 years) and 12 young patients, mean age 24 years (range 18–32 years) undergoing general anaesthesia. A compound muscle action potential was monitored continuously throughout anaesthesia, using an electromyograph and the train‐of‐four twitch technique. The rate of onset and maximum block achieved were similar in both the young and elderly patients, as were the times to 20% recovery of the first twitch compared with control (T1: T0) and fourth twitch compared with the first, (T4: T1). In contrast, the time to 70% recovery of T1: T0 was significantly prolonged in the elderly (138 as compared with 89 minutes: p < 0.01) as was the recovery index (25–75%) for T1: T0 (95 as compared with 46 minutes: p < 0.01) and the time to 70% recovery of T4: T1 (181 as compared with 131 minutes: p < 0.05). The recovery curves for T1: T0 and T4: T1 were also significantly different in the elderly from the young group (p < 0.01 in both instances). These results show that the duration of action of alcuronium is significantly prolonged in the elderly.

Prolonged paralysis following an infusion of alcuronium in a patient with renal dysfunction

The case is described of a patient who underwent artificial ventilation in an intensive therapy unit and received an infusion of alcuronium 10 mg/hour for more than 4 days, in the presence of significant renal (and later, some degree of hepatic) impairment. Prolonged and profound neuromuscular block persisted despite haemodialysis (5 hours on each of 3 days) followed by 72 hours of continuous haemofiltration; it appeared to resolve only after plasma exchange (4 litres). The total period of persistent block, for 9 days after the infusion had been stopped, is thought to be the longest period ever reported after administration of alcuronium. Neuromuscular block was monitored throughout this period using the train‐of‐four twitch technique. The potentiating effects of concurrent aminoglycoside therapy and hepatic dysfunction on the degree of paralysis are discussed.

Acute acalculous cholecystitis following multiple skeletal trauma. A report of three cases

Three cases of acute acalculous cholecystitis are reported in patients with multisystem failure following major long‐bone trauma. The diagnosis should be suspected in any such patient who develops septicaemia from an unidentified site. A high index of suspicion should be maintained, especially in patients who are sedated or in receipt of mechanical ventilation of the lungs and in whom physical signs may be minimal or absent.