A case of hyperkalaemia associated with hypocalcaemia.

An 84-year-old woman presented with lethargy and anorexia. Although routine biochemistry demonstrated mild hyponatraemia, moderate hyperkalaemia and severe hypocalcaemia, the patient did not demonstrate the usual symptoms of hypocalcaemia. An electrocardiogram did not demonstrate evidence of hyperkalaemia or hypocalcaemia. Repeated biochemistry confirmed hyponatraemia but that was associated with hypokalaemia and normocalcaemia. Initial management involved correction of the hyponatraemia and hypokalaemia with appropriate intravenous fluids. If serum biochemistry demonstrates hyperkalaemia in association with hypocalcaemia, pseudohyperkalaemia and pseudohypocalcaemia caused by contamination with potassium ethylenediaminetetraacetic acid should always be considered. This can be confirmed by repeating biochemistry, but ensuring the serum gel tube is drawn first when taking multiple blood samples to avoid this contamination.

Should we aspirate middle-ear effusions prior to insertion of ventilation tubes?

BACKGROUND: Routine aspiration of middle-ear effusions prior to ventilation tube (grommet) insertion is practised by many surgeons. It has been suggested that removing the fluid from the middle ear improves immediate post-operative hearing levels and reduces the chance of the ventilation tube becoming obstructed. The potential adverse effects of applying suction to the middle ear include acoustic trauma and an increased risk of tympanosclerosis and otorrhoea. We undertook a review of the literature in order to determine the benefits or side effects associated with middle-ear aspiration prior to ventilation tube insertion. OBJECTIVES: To compare clinical outcomes associated with aspirating versus not aspirating the middle ear prior to ventilation tube insertion. METHODS: The Cochrane ENT group trials register, DARE, the Cochrane central register of controlled trials (CENTRAL), MEDLINE (1960-2005) and EMBASE (1960-2005) were searched using relevant terms. Reference lists of selected studies were scanned for additional research material. RESULTS: Seven studies were identified, of which three fitted the inclusion criteria of our review. Current evidence suggests that aspiration of middle-ear effusions prior to insertion of ventilation tubes is not associated with any improvement in clinical outcome, in terms of post-operative hearing levels, otorrhoea or rates of blockage of ventilation tubes. Significantly increased rates of tympanosclerosis were observed in one study and the development of acoustic trauma was observed; however, no significant association was confirmed. Although more research is needed, there is no evidence that aspiration of middle-ear effusion prior to grommet insertion confers any advantage.