Effectiveness and sequelae of very low-dose suxamethonium for nasal intubation.

We have studied the effectiveness and sequelae of low-dose suxamethonium in 60 day-case oral surgery patients requiring nasal intubation. Anaesthesia was induced with propofol and alfentanil; 60 patients were allocated randomly to three groups of 20 patients and received no suxamethonium, suxamethonium 0.25 mg kg-1 or 0.5 mg kg-1. All patients received i.v. fentanyl and diclofenac 100 mg rectally for analgesia. Good intubating conditions were produced in all 20 patients receiving suxamethonium 0.25 mg kg-1, in 19 patients receiving suxamethonium 0.5 mg kg-1 and in 11 patients not receiving a neuromuscular blocker. The incidence of postoperative myalgia after suxamethonium 0.25 mg kg-1 (20%) did not differ significantly from the incidence after propofol and alfentanil alone (28%).

Advances in monitoring in intensive care: continuous mixed venous oxygen saturation and right ventricular ejection fraction.

Direct cardiorespiratory measurements and the use of optimum values to guide therapy have been associated with improved survival in a number of conditions causing critical illness. Increasingly sophisticated monitoring that provides more accurate and reproducible assessment of the cardiorespiratory system at the bedside is pivotal to this better outcome. The inclusion of fibreoptic filaments and fast response thermistors in pulmonary artery catheters makes possible the continuous monitoring of mixed venous oxygen saturation and the measurement of right ventricular ejection fraction. Although the place of measurement and manipulation of these variables in critically ill patients has yet to be fully defined, clinical studies are promising. We discuss some practical aspects of the use of these measurements and some potential clinical applications. Additionally, some of the studies in which the use of these measurements is increasing our knowledge of the pathophysiology of critical illness and contributing to improved management of critically ill patients, are highlighted.

Drug-induced hyperthermia.

Drugs with antidopaminergic properties and those capable of stimulating serotonin release can be responsible for hyperthermia syndromes such as neuroleptic malignant syndrome and serotonin syndrome. Dopamine and serotonin are important neurotransmitters in temperature regulation and it is likely that these reactions result from drug-induced changes in neurotransmitter levels. We describe three cases of drug-induced hyperthermia, discuss their aetiology and management, with both general measures and therapies designed to redress neurotransmitter imbalance.