SummaryThe arterial tourniquet is widely used in upper and lower extremity surgery and in intravenous regional anaesthesia. The local and systemic physiological effects and the anaesthetic implications are reviewed. Localised complications result from either tissue compression beneath the cuff or tissue ischaemia distal to the tourniquet. Systemic effects are related to the inflation or deflation of the tourniquet. Safe working guidelines for the application of an arterial tourniquet have not been clearly defined.

SummaryVasopressin and its analogue, terlipressin, are potent vasopressors that may be useful therapeutic agents in the treatment of cardiac arrest, septic and catecholamine-resistant shock and oesophageal variceal haemorrhage. The aim of this article is to review the physiology and pharmacology of vasopressin and summarise its efficacy and safety in clinical trials and its subsequent therapeutic use. Recent studies indicate that the use of vasopressin during cardiopulmonary resuscitation may improve the survival of patients with asystolic cardiac arrest. Vasopressin deficiency can contribute to refractory shock states associated with sepsis, cardiogenic shock and cardiac arrest. Low doses of vasopressin and terlipressin can restore vasomotor tone in conditions that are resistant to catecholamines, with preservation of renal blood flow and urine output. They are also useful in reducing bleeding and mortality associated with oesophageal variceal haemorrhage. The long-term outcome of the use of these drugs is not known.

SummaryGamma-hydroxybutyric acid (GHB) is no longer used as an anaesthetic induction agent because of the high incidence of myoclonic seizures and vomiting. However, it is used occasionally in Europe for the treatment of narcolepsy, alcohol dependence and opiate dependence. Since the early 1990s, GHB has become a drug of abuse in youths for its euphoric, sedative and anabolic effects. Common adverse effects include a rapid onset of drowsiness, nausea, vomiting, myoclonic seizures and coma of short duration. Clinicians should be alert for these adverse effects and consider the possibility of GHB abuse in young adults with unusual clinical presentations in the emergency department.

Two patients with cortical blindness following hypoxic episodes are reported. The characteristics of the syndrome are described. Attention is drawn to the lack of awareness of this complication of hypoxia.