Respiratory and hemodynamic effects of halothane in status asthmaticus.

The respiratory and hemodynamic effects of halothane in patients with status asthmaticus who required mechanical ventilation was evaluated. Halothane was administered in 12 patients in a concentration of 1% for thirty minutes. Standard drug treatments and ventilator settings were not modified during halothane administration. The following data were collected before and after halothane administration: arterial blood gases, peak inspiratory pressure, VD/VT, pulmonary arterial pressure, right heart pressures and cardiac index (by means of the thermodilution method). After halothane treatment PaCO2 significantly decreased, arterial pH increased, peak inspiratory pressure decreased and VD/VT decreased significantly. Mean pulmonary arterial pressure and right heart pressures decreased and the cardiac index was unchanged. The heart rate significantly decreased and arrhythmias did not occur during halothane administration. The administration of halothane in patients with status asthmaticus requiring mechanical ventilation produces a rapid reduction in bronchospasm and barotraumatic injury and a rapid improvement in arterial blood gases, without any adverse hemodynamic effects.