Alan Van Poznak

A clinical evaluation of methoxyflurane in man.

A CLINICAL EVALUATION OF METHOXYFLURANE IN MAN F. JOSEPH;ALAN POZNAK;E. RICHARD;M. FRANCIS;MANFRED ALEXANDER; Anesthesiology

Prevention of Air Embolism with Positive End Expiratory Pressure

Pulmonary air embolism is recognized as a possible complication of neurosurgical procedures performed with the patient in the sitting position. A variety of preventive and therapeutic modalities have been proposed in the literature. We have used a consistent regimen consisting of precordial Doppler monitoring, measurement of end expiratory CO2, the semireclining position, and positive end expiratory pressure (PEEP). A right atrial catheter was not used. This approach has given good results in 81 patients; there was significant air embolism in only 1 case (1.2%). We believe that PEEP is as important in the prevention as it is in the treatment of pulmonary air embolism. By flexibly adjusting the level of PEEP, one may recreate the hemodynamic equivalent of the prone position, thereby eliminating the risk of venous air embolism and simultaneously the need for right heart catheterization.

Evaluation of continuous monitoring of tissue pH in cats.

An improved continuous tissue pH monitoring system, designed for human subcutaneous fetal scalp tissue, was evaluated in 10 cats for total of 60 hours. Respiratory acidosis was induced with and without hypoxia to model the pathology of human clinical fetal distress. Arterial and venous pH were sampled every 15 minutes and the values were compared to those from the pH monitor system. The values paralleled arterial and venous blood pH, with correlation coefficients up to 0.98 under various pathologic acidotic conditions.