When Should We Order Preoperative Complete Blood Count and Urinalysis? : A systematic review and clinical practice guidelines

Routine preoperative investigation is expensive especially at this time when Thailand is suffering a severe financial crisis. Objectives of the study were to apply a systematic review to answer the question whether routine preoperative investigation affected health outcomes; and to construct clinical practice guidelines for preoperative complete blood count (CBC) and urinalysis (UA). The guidelines were prepared for elective, non-cardiothoracic surgery in adult patients. Methods of the study were Medline search (1980-1998) and a search of studies published in Thailand. Criteria for high validity and reliability were applied to paper selection. The results of the systematic review were discussed among anesthesiologists and other specialists and the guidelines were drawn by consensus. Results from the systematic review found that there were no randomized controlled trials to answer the question and no studies reported health outcomes. Routine preoperative CBC and urinalysis yielded few clinically significant positive results and was not very useful for patient care. From this review and the consensus, we proposed a guidelines, which consisted of a history questionnaire, physical examination and indication for investigation. For the pre-operative CBC the indication were: age ≥ 60 years, would have an operation that needed blood transfusion, had acute or chronic blood loss, malnutrition, pregnancy, heart disease, cancer, chronic renal failure, liver disease, severe infection, SLE, connective tissue disease, radiotherapy or chemotherapy. The guidelines for preoperative UA were: pregnancy, diabetes, abnormal urination, chronic renal failure, SLE or connective tissue disease. Preoperative CBC and UA requests according to these guidelines should be more cost-effective and routine preoperative investigation should be abandoned