A case of pseudohyperkalaemia and thrombocytosis.

An unusual cause of "hyperkalaemia" was observed in a neurosurgical patient admitted to our intensive care unit. The cause of the hyperkalaemia was not known initially and treatment with cation ion exchange resin was initiated to lower the elevated serum potassium level. The concurrent occurrence of thrombocytosis and hyperkalaemia raised the possibility of psuedohyperkalaemia associated with thrombocytosis. Simultaneous measurement of plasma and serum potassium with the Hitachi 917 Analyzer (indirect ion selective electrode, coefficient of variation = 1% to 2%) confirmed the diagnosis. Correlation between thrombocytosis and pseudohyperkalaemia was found to be highly significant (r = 0.54; P = 0.014). It is estimated that for for every 100 x 10(9)/L of platelets, an increase of 0.07 to 0.15 mmol/L of potassium is expected. In thrombocytosis, plasma rather than serum potassium should be measured.

Difficult pulmonary artery catheterization in a patient with persistent left superior vena cava.

A persistent left superior vena cava is an uncommon congenital abnormality. It arises when the left anterior cardinal vein fails to regress during the embryonic period. Although such patients are usually asymptomatic, they may have associated cardiovascular abnormalities. The anaesthetist may encounter difficulty in the insertion of pulmonary artery catheters. Other implications in the management of these patients in the operating theatre or intensive care unit are discussed.

Severe laryngospasm without intravenous access--a case report and literature review of the non-intravenous routes of administration of suxamethonium.

Severe laryngospasm may occur during inhalational induction of paediatric patients. Effective and rapid treatment of this complication is extremely important to prevent severe hypoxia. The treatment of choice is intravenous suxamethonium if muscle relaxation is desired. However, in the absence of intravenous access, alternate routes of administration have to be considered. The rapidity and the effectiveness in treating laryngospasm by these non-intravenous routes are important to the outcome of the patient. Though the intramuscular route may be relatively slower in onset time (time taken to reach maximum effect of paralysis) compared with the intravenous route, clinical experience so far indicates satisfactory result in the treatment of laryngospasm. Current evidences indicate that the intraosseous route is probably superior to the intramuscular route and comparable to the intravenous route in terms of onset time.