2006 OPEN FORUM Abstracts
THE MISCONCEPTION OF EXPECTED ARTERIAL BLOOD GAS RESULTS IN THE EMERGENCY DEPARTMENT
Anne Schaer, RRT, Tim Frymyer, BS, RRT, David
Mussetter, BA, RRT, Michael Trevino, MS, RRT, Gary Weinstein, MD, FCCP,
Presbyterian Hospital of Dallas, Dallas, Texas.
Background: We are a large metropolitan teaching hospital. Our emergency department (ED) has 49 beds with an average daily census between 235 - 250 patients. Included in the ED list of top 25 DRGs are pneumonia, congestive heart failure, obstructive lung disease such as chronic bronchitis and asthma, and chest pain. We perform roughly 33,000 arterial blood gases (ABGs) on our campus per year with approximately 1,250 of those occurring in the ED. The ED physicians historically have had varied and unpredictable ABG ordering practices and do not use a standard protocol or algorithm. Staff therapists report frustration with the ED physicians who seem liberal with their use of the ABG assessment. This became the motivation for us to ascertain what percentage of ABGs drawn in the ED is abnormal and/or critical.
Method: We first determined what constituted a normal blood gas result in our facility by referring to our policy and procedure manual for ABG normal ranges: pH 7.35 - 7.45, PCO2 35 - 45, PO2 60 - 100, HCO3 22 - 26, BE ±2, SpO2 > 95%. Critical values were then described as the following: pH <7.20 or >7.60, PO2 < 50, HCO3 < 12 per our policy and procedure manual, as well. We retrospectively reviewed 420 consecutive ED ABGs over a four month time period. Twelve results were excluded leaving 408 ABGs for analysis. ABGs were excluded if the result was:
a) suspected of not being arterial  or b) processed two or more times by the information system . No neonatal blood gases were drawn in the ED during this time frame.
Results: We found that 212 (52%) ABGs drawn in our ED were abnormal per our criteria. Within that abnormal group, 34 were deemed critical by our facility. The remaining 196 (48%) were described as normal, which included those characterized as being fully compensated.
Conclusion: The very nature of ED care implies there will be a high utilization of healthcare resources, especially as they relate to diagnostic functions. The ED is a prime example of where the "number to treat" is small enough to justify the high order frequency. The misconception that we draw more normal than abnormal ABGs at our facility was proven false, through this simple evaluation of the data. Therefore, we will focus on educating the staff as it pertains to the information collected. However, additional evaluation of individual physician's ordering practice might also prove to be beneficial. There may be some physician's who order an excessive amount of ABGs which offer little clinical significance. The use of an algorithm may become a result of such a critical evaluation.