Respiratory effects of halothane in a patient with refractory status asthmaticus

We describe the case of a 36 year old patient who was admitted to the intensive care unit (ICU) for an acute asthma attack that failed to respond to conventional treatment and required mechanical ventilation. The patient's condition improved after halothane was administered; treatment with this inhalational anaesthetic lasted 7 h, and the beneficial effect was obtained by employing concentrations between 0.5 and 2%. Under constant mechanical ventilator settings, a highly significant linear correlation between peak airway pressure and arterial pCO(2)(r: 0.98 P<0.001) was observed. The decrease in p(a)CO(2)induced by halothane may be explained by the diminished dead space that results from the drop in peak airway pressure. Arterial hypotension, which improved with inotropic agents, was the only complication that seemed related to the inhaled anaesthetic. The patient was extubated 24 h after her arrival to the ICU and discharged 72 h later. A causal relationship between the administration of halothane and clinical improvement is suggested.