Mivacurium or vecuronium for muscular relaxation in day-case surgery.

Anaesthetic agents for day-case surgery ideally should have a short duration of action. This study was designed to compare the efficacy and safety of mivacurium and vecuronium for healthy adults undergoing dental day-case surgery. Thirty fit healthy adult patients (ASA I or II) randomly received either mivacurium 0.15 mg kg-1 (n = 15) or vecuronium 0.1 mg kg-1 (n = 15). Anaesthesia included propofol, fentanyl, nitrous oxide and isoflurane. Maximum depression of T1 was greater in the vecuronium group (99.8%) than in the mivacurium group (98.3%). There was no difference between grade of intubation at 2 min between the two groups, although patients receiving vecuronium had a more profound block at the time of intubation than those who received mivacurium (89.2% vs. 78.9%). Recovery to 10% T1 was faster in the mivacurium group (11.2 min vs. 33.1 min). All patients in the vecuronium group received neostigmine at the termination of surgery. The neostigmine evoked recovery index in the vecuronium group (4.39 min) was less than the spontaneous recovery index in the mivacurium group (6.78 min). One patient in the mivacurium group had a low plasma cholinesterase concentration (0.43 ku L-1); recovery times however, fell within the 95% confidence intervals (CI) for the group. There was no correlation between cholinesterase levels and recovery time. Mivacurium may be the more appropriate agent for dental day-case surgery because it has a shorter duration of action and does not generally require antagonism with an anticholinesterase.

The incidence of minor sequelae following anaesthesia in children.

A survey was performed to estimate the incidence of the minor sequelae of anaesthesia in children. During an eight-month period 266 children, aged five years and over, were personally interviewed by an anaesthetist following recovery from anaesthesia. At interview the child was questioned to ascertain any morbidity suffered and record was made of the operation performed and the anaesthetic administered. Data were then evaluated, using multivariate analysis, to identify risk factors for the more common sequelae. This study revealed a higher incidence of the minor sequelae of anaesthesia in children than had previously been reported. The three most common sequelae recorded were nausea (48.1%), vomiting (35.0%), and sore throat (31.4%).

Oxygen saturation during endoscopic retrograde cholangiopancreatography: a comparison of two protocols of oxygen administration.

Patients having endoscopic retrograde cholangiopancreatography (ERCP) are generally elderly and require sedation while in the prone position. These factors may be expected to aggravate any risk of arterial hypoxia. This study evaluated two protocols of oxygen administration, one with and one without pre-oxygenation. In 25 patients in whom pre-oxygenation with 4 litres/minute for five minutes before sedation was used, followed by continuous oxygen administration, arterial oxygen saturation did not fall below 90% at any stage during the procedure. By contrast, in 25 patients who were not pre-oxygenated oxygen saturation fell below 90% in nine (36%). As expected, hypoxia occurred most frequently during the early stages of sedation and endoscope insertion. Hypoxia did not occur in association with operations such as sphincterotomy, stone extraction or stent insertion. This study confirms that arterial hypoxia is a common event during ERCP and can be completely prevented by pre-oxygenation with four litres of oxygen given intranasally for five minutes before sedation.

Apnoea after retrobulbar block.

Two cases of apnoea after retrobulbar block for cataract surgery are described. The possible causes and mechanisms of this complication, its detection and management are discussed.