agency for healthcare research and quality (AHRQ) just came out with their synthesis of the data on routine preoperative testing (see link: http://effectivehealthcare.ahrq.gov/search-for-guides-reviews-and-reports/?pageaction=displayproduct&productID=1846 ). assessed literature on kids and adults of routine testing vs no testing or ad hoc testing, and routine vs per-protocol testing (per-protocol testing is testing a subset, eg EKG for those > 50yo, or hct in premenopausal women). 57 studies reviewed (14 comparative and 43 cohort). results:
good news: data for cataract surgery is the best: routine pre-op testing (EKG, metabolic panel or glucose, cbc) has no effect on total perioperative complications.
bad news: insufficient evidence for all other procedures and insufficient evidence comparing routine and per-protocol testing. no evidence regarding quality of life or satisfaction, resource utilization, or harms of testing. and, results of cataract surgery pre-op is not applicable to other patients undergoing other higher risk procedures. even tonsillectomy/adenoidectomy in kids — just one retrospective, flawed study, so unable to draw conclusions.
the issue is that there just are not enough good studies (though 4581 citations assessed). many studies done, but poor quality. good studies need to look at real benefits/risks, including positive outcomes by testing (fewer medical complications, appropriate changes in perioperative management) vs risks (false positives or irrelevant findings, leading to further testing with attendant complications — medical and psychological; unnecessary delays in surgery; unnecessary radiation exposure; cost).