When should we order preoperative blood glucose, BUN, creatinine, or electrolytes: A systematic review and clinical practice guidelines.

ABSTRACT

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 checking of blood glucose, BUN, creatinine and electrolytes. 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 suggested there were no randomized controlled trials to answer the question and no studies reported health outcomes. From this review and the consensus, we proposed guidelines which consisted of a history questionnaire, physical examination and indications for investigation. For the preoperative checking of blood glucose, the indications were age > 60 years, obesity, diabetes, hypoglycemia, liver disease, alcoholism, severe infection, alteration of consciousness, hypothalamic, pituitary, pancreatic and adrenal disease, and steroid therapy. The common indications for both BUN/creatinine and electrolytes checking were age > 60 years, undergoing TURP, TUR-BT and major KUB surgery, obesity, diabetes, hypertension, chronic renal failure, renal disease, liver disease, alcoholism, severe infection, severe vomiting or diarrhea, history of fluid, acid base or electrolyte disturbance, alteration of consciousness, hypothalamic, pituitary, pancreatic and adrenal disease, ADH abnormality and diuretic or digoxin therapy. The additional indications for electrolyte checking were convulsion or muscle weakness, CNS disease with increased ICP and steroid therapy.