Early Experience with Magnesium Administration in Irukandji Syndrome

The administration of magnesium sulphate is a proposed novel therapy for Irukandji syndrome1. In this non-randomized, unblinded case series, data from ten patients who received magnesium salts are reviewed. Magnesium sulphate boluses of 10 to 20 mmol, in the six patients for which there was adequate data, reduced pain scores immediately after administration from 8.7±1.5 to 2.8±2.8 (Wilcoxon rank-sum test, P=0.03). In ten patients blood pressure decreased with a mean difference of −18 mmHg in mean arterial pressure. Magnesium requirements in individual patients varied markedly. Pain on injection occurred in four patients, three of whom had received peripherally administered magnesium chloride, and one patient reported transient ptosis after administration of magnesium sulphate 166 mmol over 18 hours in the setting of severe Irukandji syndrome.

Magnesium sulphate administration appears to attenuate pain and hypertension in Irukandji syndrome and warrants further evaluation in this setting.

High Frequency Oscillation in the Adult Intensive Care Unit. Nearly Mainstream?

High frequency oscillatory ventilation (HFOV) was first described in 1959. It has had variable uptake in critical care with greater use in neonatal and paediatric intensive care units (ICU) than in adults1. In this issue, Boots et al2 describe the use of HFOV across a wide spectrum of patients with severe respiratory failure due to pandemic H1N1 influenza. Units from across Australia and New Zealand contributed data regarding patients admitted during the pandemic. The fact that there is an established network and organisational structure for the study of intensive care outcomes in Australia and New Zealand facilitated the rapid mobilisation of resources to gather data on the intensive care effects of the pandemic, and those involved should be congratulated. Other data on the impact of pandemic H1N1 on Australian ICUs in 2009 have already been published3.

Inhaled aerosolized prostacyclin as a selective pulmonary vasodilator for the treatment of severe hypoxaemia

Two case reports are presented where inhaled aerosolized prostacyclin (IAP) was used to good effect as a selective pulmonary vasodilator. It was used in the treatment of a patient with severe hypoxaemia secondary to amniotic fluid embolism and for hypoxaemia secondary to the acute respiratory distress syndrome (ARDS) in a patient with acute on chronic liver failure and intra-abdominal sepsis. An apparent dose-response curve is demonstrated in the second case. A dose of IAP of 30-40 ng/kg/min produced an effect on oxygenation in the patient with liver failure equal to that seen at the maximal dose of (50 ng/kg/min). Reduction in dose below 30 ng/kg/min resulted in a deterioration in oxygenation towards baseline/pre-treatment levels. Inhaled aerosolized prostacyclin is a potent pulmonary vasodilator with little or no systemic hypotensive effect. It is simple to administer and would appear to be a viable alternative to inhaled nitric oxide.