I keep six honest serving-men
(They taught me all I knew);
Their names are What and Why and When
And How and Where and Who.
—Rudyard Kipling, "I Keep Six Honest Serving Men"
These lines by Rudyard Kipling sum up the entire study and practice of anesthesiology, starting right from the preanesthetic checkup, which essentially involves an in-depth history taking, examination to elicit the relevant signs, and ordering laboratory investigations to confirm the diagnosis. It is the laboratory tests that are most contentious. To add to the above 6 men, I would suggest adding “If” and “Whether,” especially in the context of laboratory testing. An anesthesiologist must consider the 2 questions before advising any test:
Whether the test is routine or indicated; and if the results would predict risk, alter management, or improve outcome.
Previous studies have shown that preoperative testing does not alter the management nor the outcome.1 The incidence of complications was similar in those who were tested and in those who were not.2
The Choosing Wisely campaign,3 National Institute for Health and Care Excellence,4 and American Society of Anesthesiologists guidelines5 thereby do not recommend any tests in healthy patients, irrespective of age for low- to moderate-risk noncardiac surgery. Investigations on the other hand may be appropriate for underlying comorbid conditions within 30 days of a planned procedure.
In spite of these guidelines formulated more than a decade back, routine tests (complete blood count, basic and advanced metabolic panels, coagulation studies, x-ray, and electrocardiography) continue to be prescribed routinely the world over.6–12
This has been brought about by a descriptive retrospective analysis of data over 4 years, from 2012 to 2016, to estimate the proportions of preoperative blood tests by Yonekura et al,13 who examined the associations between patient- and institutional-level factors and preoperative blood tests using multilevel logistic regression analysis in patients who had undergone an ophthalmic procedure with other low-risk surgeries as reference. Although their results do not vary much from other developed countries, they do bring out an association of preoperative testing with coexisting morbidity, medications, general anesthesia more than regional anesthesia, inpatients, and institutions with >100 beds.
The study by Yonekura et al13 provides an interesting insight into the prevalence of testing in Japan for low-risk surgeries. With a large sample size and varied institutions from the national database of Japan, it provides an in-depth insight of tests performed and their likely and associated factors. The researchers conclude an overuse of laboratory tests, as only 16% of patients had comorbidities. The results may not be generalized to other surgeries or populations because it is limited by inability to distinguish between routine and indicated tests, although this can be attributed to the retrospective nature of the study.
This brings us to the question of “why laboratory testing remains prevalent for low-risk surgeries despite evidence and guidelines against it?” Research suggests that laboratory testing should be performed only to: (1) confirm diagnosis; (2) detect unsuspected abnormalities that might influence the risk of perioperative morbidity or mortality; (3) establish a baseline value for a test that has a high likelihood of being monitored and changing after the surgical procedure is complete; (4) alter management; or (5) improve outcomes.5,7,10,14 However, laboratory testing continues to be overused because of: (1) institutional policies and procedures; (2) difficulty changing ingrained behavior; (3) belief that other physicians want tests performed, leading to concerns about surgical delays; (4) complex health care environments; (5) medicolegal considerations; and (6) economic considerations.10,14
Largely, populations with low health literacy and/or limited access to health care services presenting late to the hospital at an advanced stage of disease, in addition to low doctor-to-patient ratio, results in an inadequate time spent with the patient, and inability of patients to provide a reliable history may require investigations in lieu of a thorough and complete history and physical examination in the hope to detect something that may have been missed. This has led to development of institutional policies and the belief that anesthesiologists may want a battery of routine tests; otherwise, the surgery may be canceled or delayed.7 However, for low-risk surgeries, any abnormalities detected in these tests are minor and generally ignored (~60% of cases),2 and the clinical management is not altered in the perioperative period (<3%).10,15 These abnormalities with no clinical relevance may result in unnecessary delay, further tests, increased economic burden, and medicolegal liability in case the abnormality is not addressed or documented in case any complication arises.14
Evidence further reveals that incidence of intraoperative and postoperative adverse events was as low as 1.5% and 4% whether patients underwent testing or not.2 The economic burden has been estimated to be $18 billion, with savings up to $10 billion annually if unindicated testing is eliminated.14 Data from other countries also indicate that as much as 50%–60% of this unnecessary cost may be reduced.2,6,7,9,14
While this may be of benefit in countries where health care is solely provided by the state (eg, the National Health Service of United Kingdom), it is exploited by the system that is corporate based and relies on payment by the individual or insurance companies. The loser in both cases is the patient, either directly or indirectly. The taxpayer money in state health services so saved may be used for other health projects; while in corporate-based systems, it would result in lower insurance premiums, albeit lower profit margins.
So what are the measures to reign in unnecessary preoperative tests? Given the variability of disease, endemism, health care practices, and penetration, a single guideline may not be applicable globally. However, a path has been shown by Yonekura et al13 by conducting a representative audit of the practices in their country to quantify the magnitude and identify the underlying factors. This would pave the way for formulation of guidelines that are region, resource, and population specific. These guidelines then need to be endorsed by the regional societies/health policies to ensure widespread dissemination and diminished medicolegal liability of the practitioner. Institutional guidelines can then be designed to ensure collaborative effort from all specialties involved in patient care.8,15 Alternatively, a single specialty (ie, anesthesiology) may be entrusted to order preoperative testing, as has been shown by previous studies, to reduce these tests and hence economic burden.10 An advanced step in this direction can be point-of-care testing being performed just before surgery.14 While small steps have been initiated in this regard, it remains to be seen whether this would translate into a giant leap for health care professionals!
Name: Nishant Kumar, DA, DNB.
Contribution: This author searched the literature and wrote and approved the final manuscript.
This manuscript was handled by: Nancy Borkowski, DBA, CPA, FACHE, FHFMA.
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2. Chung F, Yuan H, Yin L, Vairavanathan S, Wong DT. Elimination of preoperative testing in ambulatory surgery. Anesth Analg. 2009;108:467–475.
3. Choosing Wisely Canada. Anesthesiology: five things physicians and patients should question. June 2017. Available at: https://choosingwiselycanada.org/anesthesiology/
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4. National Institute for Health and Care Excellence. Routine preoperative tests for elective surgery. April 5, 2016. Available at: www.nice.org.uk/guidance/ng45
. Accessed December 19, 2017.
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