Effects of NO Inhalation Therapy on Ambient Air in Intensive Care Unit

Abstract

Determination was made of the concentrations of ambient NOx (nitric oxide+nitrite oxide), to clarify whether the NO (nitric oxide) inhalation therapy would lead to room air pollution at this ICU. NO (5-10ppm; 800ppm 50-200ml/min) was administered to an infant with pulmonary hypertension in ICU. The exhaust gas was fully scavenged during mechanical ventilation, but not during short period of tracheal suction by manual ventilation. NOx was measured continuously for 11 days with or without NO at the bedside of the patient, and for 9 days at the outdoor of the ICU. During the course of this study, NOx varied from 0.01 to 0.12ppm at these sites, but the relationship between the NO inhalation therapy and the ambient NOx values could not be found. According to a questionnaire, 46% of the staff of ICU experienced mild headache and 28% felt a sense of smell, especially during manual ventilation. During manual ventilation without scavenging exhaust gas, transient increase in NOx (to 0.24ppm) was observed. These results suggest that scavenging and monitoring of NO gas are inevitable for the safe administration of NO.