Effects of a Respiratory Stimulant on Intracranial Pressure and Cerebral Blood Flow

The main cause of sudden death in patients with intracranial hypertension is respiratory failure. This study was a search for a clue to respiratory treatment which could be used at the scene of an accident. For this purpose, intravenous administration of respiratory stimulants was thought to be the most simple measure. Doxapram hydrochloride (Doxapram) was used to stimulate respiration impaired by balloon-induced intracranial hypertension in cats. Intravenous administration of Doxapram resulted in sufficient respiratory stimulation at the dose of 1.0 mg/kg, but could not decrease PaCO2 lower than 25 torr. In 4 out of 10 cats, administration of Doxapram improved the respiratory condition and increased cerebral perfusion pressure and regional cerebral blood flow. Further investigation was required to find the best timing of Doxapram administration to maximize life preservation.