Supplemental oxygen use in ischemic stroke patients: does utilization correspond to need for oxygen therapy?

BACKGROUND In 1994, the American Heart Association Stroke Council concluded that there were no data to support the routine use of supplemental oxygen in patients who had a stroke. More recently, supplemental oxygen has been suggested to be potentially detrimental. The purpose of this study was to determine the extent of oxygen use in ischemic stroke patients and whether patients receiving oxygen had indications for its use. METHODS A literature search was performed to generate a comprehensive list of explicit criteria for supplemental oxygen use. When the literature disagreed, the criteria were included in the list to overestimate rather than underestimate the justification for oxygen use. A retrospective chart review of consecutive, nonintubated, ischemic stroke patients admitted to a university hospital was performed. Statistical tests and logistic regression models were constructed to identify the presence of unjustified oxygen use within the sample. Hospital charges were used to quantify opportunities for resource conservation. RESULTS A total of 167 patient charts were reviewed yielding a total of 600 inpatient days abstracted. One hundred two patients (61.1%) received oxygen during some portion of their hospitalization. Of the 322 days that patients received oxygen, 147 (45.6%) met at least 1 criterion for oxygen use. Of the 278 days that patients did not receive oxygen, 69 (24.8%) met at least 1 of the criteria for oxygen use. There were 384 days for which no criteria were met. Of these, a patient still received oxygen 45.6% of the time (175 days). Factors associated with oxygen use included the presence of at least 1 justifying criteria as well as increasing age and male sex. Withholding oxygen from those not medically justified by the criteria could produce resource savings of roughly 45%. CONCLUSIONS Using a literature-based list of criteria for supplemental oxygen use, only 45.6% of days of oxygen use were justified in our ischemic stroke population. This study demonstrates that oxygen therapy is commonly given to ischemic stroke patients without clear indication, and opportunities exist for substantial resource conservation.