Written guidelines for laboratory testing in intensive care--still effective after 3 years

Abstract

Objective: The aim of the study was to examine the effect of time on written guidelines for laboratory testing in an intensive care unit by comparing the numbers of tests performed with those performed three years previously.

Methods: In 1995, guidelines were developed for blood test ordering in the Waikato Hospital intensive care unit, which when implemented resulted in a decrease in all blood tests performed by 16.6% in a group of general intensive care patients and by 25.9% in a group of post cardiac surgery patients. We repeated this study on similar groups of patients to see if the guidelines were still effective. Data on age, APACHE II score, diagnosis, and ventilation time were collected. Comparisons were made of tests performed per patient and per ventilation time in hours.

Results: In the general intensive care patient group, there was an increase of 2.1% tests performed per patient, but a decrease in tests performed per ventilation time of 5.6%. In the postoperative cardiac surgery patient group, the total number of tests performed per ventilation time decreased by 4%. The arterial blood gases performed per patient increased by 10.7% in the general intensive care patient group, and decreased by 14.3% in the postoperative cardiac surgery patient group. However, when the number of arterial blood gases performed per ventilation time were compared with the 1995 study, there was no difference in the general intensive care patient group, while there was a reduction by 8.3% in the postoperative cardiac surgery patient group.

Conclusions: Three years after the implementation of guidelines for laboratory testing in an intensive care unit, there was no return to the level of testing recorded before the guidelines were introduced. The number of tests per ventilation time decreased by 4% in postoperative cardiac surgery patients and decreased by 5.6% in the general intensive care patients. In our study written guidelines remained effective three years after their introduction.