DOES SIGNIFICANT ARTERIAL HYPOXEMIA ALTER VITAL SIGNS

Study Objective: To determine the cardiovascular and respiratory effec ts of arterial hypoxemia in adult volunteers. Design: Prospective, sub ject-controlled Setting: University-affiliated hospital. Subjects: 16 awake, unsedated, unanesthetized adult volunteers. Interventions: Insp ired oxygen concentration (FIO2) was decreased in decrements to reduce pulse oximeter values to a range of 95% to 90%, 89% to 85%, 84% to 80 %, and 79% to 70%. Measurements and Main Results: Heart rate (HR), blo od pressure (BP), respiratory rate (RR), arterial blood PH gas tension s, and oxyhemoglobin saturation were determined during normoxia and ea ch level of oxyhemoglobin desaturation. FIO2 was reduced from 22% to 1 0%. Arterial blood oxyhemoglobin saturation and oxygen tension ranged from 100% to 71% and 103 to 35 mmHg; respectively. There were no signi ficant changes in RR, BP, or HR during the study. Conclusions: HR BP, and RR are not reliable indicators of arterial hypoxemia in awake volu nteers. IS this finding is also true for sedated or anesthetized patie nts, then continuous monitoring with pulse oximetry should be used whe never patients are at risk for arterial hypoxemia. Stable HR BP, and R R may not eliminate the possibility of significant a arterial hypoxemi a and impending catastrophic events. (C) 1997 by Elsevier Science Inc.