Prevalence of normal and abnormal preoperative laboratory tests in patients undergoing adenotonsillectomy

Abstract Background The value of preoperative blood tests in adenotonsillectomy is not clear. This retrospective study was designed to review any potential benefit and the cost of preoperative tests in adenotonsillectomy. Method In this descriptive study, the medical profiles of 312 patients who had adenotonsillectomy from March 2017 to September 2017 in Besat Hospital of Hamedan were reviewed. Three patients had missing records, and data from the other 309 patients were analyzed. All the performed preoperative tests were included and the results were reported as either normal or abnormal. Results Among 309 patients, 129(42%) were female and 180 (58%) were male. 305(98.7%) patients were under 16 years old and 4(1%) patients were above 16 years old. Complete blood count (CBC), prothrombin time (PT), partial thromboplastin time (PTT), international normalized ratio (INR), clotting time (CT), bleeding time (BT), and platelet count (Platelet) were performed for all 309 patients while fasting blood sugar (FBS), blood urea nitrogen (BUN), and creatinine (Cr) were checked in 10, 4, and 11 patients, respectively. Results of all BT, CT, BUN, Cr, and FBS were within the normal range. Upon initial test, abnormal results were found in 3.6% (CBC), 3.9% (PT), 3.6% (PTT), 3.2% (INR) and 1.9% (Platelet) of patients. After repeat testing abnormal results were found in 1.6% (CBC), 0.6% (PT), 0.6% (PTT), 0.6% (INR), and 0.3% (Platelet) of patients. Also, 3(0.97%) patients required reoperation due to postoperative hemorrhage and only one of them had abnormal preoperative tests. In this study, 99.5% of the preoperative tests were in the normal range and 99.3% of the laboratory costs belong to tests with normal results. Conclusion Routine preoperative tests in patients undergoing adenotonsillectomy did not show any effect on the postoperative bleeding. Unless there is a clinical indication, routine preoperative tests can be safely avoided and prevent unnecessary economic costs to patients and decrease the burden on the health care system.