Sixty-five per cent survival has been achieved in a group of patients with severe ARDS and a predicted mortality of 92%, by the use of Gattinoni's technique of extracorporeal C02 removal. In patients and animals the technique has usually resulted in rapid improvement in the radiographic appearance and lung function. There are several possible mechanisms by which the technique may facilitate lung repair, including improvement of lung tissue oxygenation, the avoidance of high airway pressures and regional alkalosis in the lung, a reduction in oxygen toxicity, and the frequently observed reduction in pulmonary artery pressure. The apparent effectiveness of the technique and other associated evidence have implications which should lead us to reconsider some aspects of our conventional management of patients with severe ARDS.

Following the failure of extracorporeal membrane oxygenation (ECMO) to influence survival in severe adult respiratory distress syndrome (ARDS), I Gattinoni has introduced low frequency positive pressure ventilation and extracorporeal CO 2 removal (LFPPV and ECC02R)~-5 and his results to date appear encouraging. A brief description of the technique appears elsewhere in this issue. 6 We report the use of this technique in a patient with severe ARDS. CASE REPORT A 33-year-old woman was admitted with a four-week history of progressive weakness and a clinical picture suggestive of Guillain Barn! Syndrome. Her chest X-rayon admission showed a collapse of the left lower lobe, but was otherwise normal, and arterial blood gas analysis showed a Pa02 of 113 mmHg, PaC02 15 mmHg, and pH 7.53, breathing spontaneously with two litres per minute of oxygen supplied by nasal cannulae. She had a vital capacity of 1.5 I and a negative inspiratory pressure of 30 cm H20. Her serum sodium on