Effects of Short-term 28% and 100% Oxygen on PaCO2 and Peak Expiratory Flow Rate in Acute Asthma*: A Randomized Trial.
Rodrigo, Gustavo J. MD; Verde, Mario Rodriquez MD; Peregalli, Virginia MD; Rodrigo, Carlos MD
[Article]
Chest.
124(4):1312-1317, October 2003.
(Format: HTML, PDF)
Study objective: We conducted the first randomized controlled study to assess the effects of short-term 28% and 100% oxygen on PaCO2 and peak expiratory flow rate (PEFR) in patients with acute severe asthma.
Patients and interventions: Seventy-four patients (mean age, 37.9 /- 9.7 years [ /- SD]; PEFR, 41.0 /- 12.1% of predicted) from two emergency departments were randomized to receive 28% or 100% oxygen during 20 min.
Results: The administration of 100% oxygen significantly increases PaCO2 (p = 0.03) and decreases PEFR (p = 0.001) as compared with administration of 28% oxygen. PaCO2 before and during oxygen administration correlated significantly (p = 0.001) in both groups. Patients breathing 28% oxygen experienced a PaCO2 fall; on the contrary, patients who received 100% oxygen showed an increase in PaCO2, particularly those with PaCO2 before oxygen treatment > 40 mm Hg.
Conclusions: This study confirmed previous observations that oxygen dose should be variable and based on achieving and maintaining target arterial oxygen saturation measured by pulse oximetry >= 92% rather than on prescribing predetermined concentrations or flow rates of inspired oxygen.
Copyright (C) 2003 by the American College of Chest Physicians