Anesthesiology
-
Patients who had upper respiratory tract gram-negative bacillary colonization and noncolonized patients were followed through surgical procedures to determine what bacterial organisms would be deposited in anesthesia apparatus. Anesthesia machines were cultured for bacteria in many locations before and after each surgical procedure. Six machines in routine operating room use were studied after use on six colonized patients and nine uncolonized patients. ⋯ Intentional contamination of a sterilized anesthesia machine with two gram-negative organisms confirmed the clinical observations. Analysis of oxygen and nitrous oxide gas sources for bacteria had negative results. Basic hygienic management of anesthesia machines will ensure safety from the standpoint of cross-infection.
-
This study investigated the effects of sodium nitroprusside (SNP) on arterial oxygen tension (Pao2), pulmonary shunt (Qs/Qt), and pulmonary vascular resistance (PVR) in the presence of atelectasis of one lung. Ten dogs were anesthetized, their tracheas intubated with a bronchial divider, and their lungs ventilated with IPPB with pure oxygen. Atelectasis of the left lung was produced by occluding the left side of the bronchial divider and ventilating the right lung. ⋯ PVR of the atelectatic lung decreased, while PVR of the ventilated lung was unchanged. The decrease in PVR in the atelectatic lung suggests that SNP decreases Pao2 and increases Qs/Qt by reversing the hypoxic pulmonary vasoconstriction. As a result, during SNP infusion, perfusion of the atelectatic lung was maintained while perfusion of the ventilated lung decreased.