No abstract

Continued elevations in Intracranial Pressure (ICP) following traumatic or ischemic compromise are known to cause markedly increased morbidity and mortality. Because of the side effects of barbiturates including hypotension and prolonged recovery time, the use of shorter-acting anesthetic agents to control ICP has been considered. Etomidate, when administered by continuous infusion, has been shown to decrease cerebral metabolism resulting in a secondary decrease in cerebral blood flow with minimal changes in cerebral perfusion pressure. We initially intended to randomize 20 patients prospectively into a study protocol that would assess the effects of either pentobarbital or the cardioprotective agent etomidate on ICP and cardiac performance. Given the sequelae of the therapy, we were only able to randomize seven patients with cerebral edema refractory to medical management to receive either etomidate or pentobarbital in a blinded fashion. Three patients who received etomidate developed renal compromise (mean low creatinine clearance 41 ml/min, range 37-44 ml/min) which was initially noted at 24 hours. We believed that this represented an adverse effect that was probably related to the study drug and the study was stopped. Each patient received a 0.30 mg/kg IV induction of etomidate and then 0.02 mg/kg/min continuous infusion for 24-72 hours titrated burst suppression. All patients also received dexamethasone 2 mg IV every six hours to prevent the adrenocortical insufficiency that might occur as a consequence of etomidate-induced suppression of cortisol synthesis. Intracranial pressure decreased (mean = 12mmHg) following the initiation of etomidate. Cardiac parameters remained unchanged (cardiac output 4.8 +/- .6 liters/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary air leaks were created in the lungs of Yorkshire pigs. Dynamic, 3D MRI of laser‐polarized 3He gas was then performed using a gradient‐echo pulse sequence. Coronal magnitude images of the helium distribution were acquired during gas inhalation with a voxel resolution of approximately 1.2 × 2.5 × 8 mm, and a time resolution of 5 sec. In each animal, the ventilation images reveal focal high‐signal intensity within the pleural cavity at the site of the air leaks. In addition, a wedge‐shaped region of increased parenchymal signal intensity was observed adjacent to the site of the air leak in one animal. 3He MRI may prove helpful in the management of patients with pulmonary air leaks. Magn Reson Med 44:379–382, 2000. © 2000 Wiley‐Liss, Inc.

In therapy of pulmonary hypertension, inhaled nitric oxide should produce additional selective pulmonary vasodilation when combined with a vasodilator whose mechanism of action is not dependent on cyclic guanosine 3',5'-monophosphate.