Wishing to reduce unwarranted use of arterial blood gas (ABG) analysis in our surgical intensive care unit (SICU), we developed criteria and an algorithm for appropriate ABG analysis. Physician housestaff, nurses, and respiratory therapists were educated about the criteria and use of the algorithm, and we then studied its effect on use of ABG analysis. METHOD: We compared numbers of appropriate and inappropriate ABG analysis in three 1-week periods: Period I, 6 months before introduction of the algorithm; Period II, 1 month after use of the algorithm began; and Period III, 4 months after the algorithm was introduced. RESULTS: In Period I, before the algorithm was in use, 42.7% of ABG analyses were inappropriate; this declined to 32.9% in Period II, 1 month after introduction of the algorithm, then to 30.8% 3 months later. The changes were statistically significant by ANOVA (p = 0.0238). There were 7.5 ABG analyses per patient-day in Period 1, 5.6 in Period II, and 5.7 in Period III; the average reduction of 1.85 analyses per patient-day was statistically significant (p = 0.00065). On an annual basis, reduction of ABG analysis at this rate would save our institution 2,415 hours of SICU practitioners' time, $11,591 in cost of blood gas kits, and $64,908 in laboratory costs. However, it was distressing that even with liberal criteria for ABG analysis, more than 30% of the analyses did not meet those standards after the algorithm had been introduced. We are seeking data about what specific criteria are being used to justify ABG analysis in the SICU, and this may help us refine the algorithm. CONCLUSION: The use of criteria for ABG analysis can reduce costs and unwarranted 'routine' use of ABG analysis.
