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Majority of Routine Screening Laboratory Examinations Prior to an Operation NOT Necessary!


Reynaldo O. Joson, MD


Department of Surgery

Ospital ng Maynila Medical Center


November 6, 2002


'Routine' tests are defined as those ordered for an asymptomatic, apparently healthy individual in the absence of any specific clinical indication except to identify conditions undetected by clinical history and examination.


There is a universal concern by medical insurers, hospital administrators, surgeons and anesthesiologists on the cost-effectiveness of routine preoperative screening investigations.  Search of the medical literature yielded papers on this topic originating from almost all countries in the world and with publications as early as the 70s and as recent as 2002.  There is NO paper that advocates routine preoperative screening investigations.  All papers are advocating selective screening with reliance placed on history (interview for symptoms and risk factors) and physical examination.


It is estimated that 60% of routine screening laboratory examinations presently being done prior to an operation as ordered by surgeons, anesthesiologists and other specialists like the internists and pediatricians are NOT necessary based on the following parameters:


  1. SMALL percentage of abnormality found in the tests ordered and done.
  2. Even if an abnormal result is present, most often, the decision-making in the initial plan of management is NOT significantly altered or changed.
  3. Outcome of the treatment in those with routine testing is NOT significantly different from those without the tests and with selective testing.


These routine screening laboratory examinations include complete blood count (CBC), urinalysis, blood chemistries, blood coagulation tests (bleeding time, clotting time, clot retraction test, prothrombin time), chest x-ray, and ECG.   These tests are usually being done in association with cardiopulmonary and pediatric clearances, which are also being practiced routinely and are considered also NOT to be necessary.


Selective screening is being advocated over routine screening in all types of operations (general surgery – head and neck, breast, abdomen, and skin and soft tissue; gynecologic surgery; pediatric surgery; orthopedic surgery; eye surgery; and ear, nose, throat and dental surgery) and in whatever age group including pediatric and geriatric patients.  Selective screening is advocated not only by surgeons but also by well-informed anesthesiologists with concern on cost-effectiveness.


Selective screening is done when data gathered from history and physical examination make a physician strongly suspects the presence of a subclinical (non-evident) condition or risk that may significantly change the plan of treatment or that may interfere with the outcome of the operation.  Below are some examples of situations in which screening tests are done using a selective approach.


1.      Complete blood count is done only if a physician strongly suspects the presence of a blood disorder because of frequent occurrence of spontaneous bruises.

2.      Hemoglobin determination (part of a blood count) is done if the patient is suspected to be pale.

3.      Blood coagulation tests are done if the patient has a history of prolonged and excessive bleeding during a previous operation or trauma.

4.      Blood sugar determination (FBS) is done only if a physician strongly suspects the presence of diabetes mellitus.

5.      Blood chemistries on kidney function (such as BUN, creatinine) are done only if a physician strongly suspects the presence of a kidney function problem.

6.      Blood chemistries on liver function (such as SGOT, SGPT, TP, alkaline phosphatase) are done only if a physician strongly suspects the presence of a liver function problem.

7.      Urinalysis is done only if the patient has symptoms of urinary disturbance such as painful urination.

8.      Chest x-ray is done if the patient has a chronic cough.

9.      ECG is done at age 70 and above who are to undergo a major operation because of the high risk of cardiac problem in this age group as borne out by scientific evidences.


In the Philippines, there exists a similar concern which was overtly expressed in a project conducted by the Philippine College of Surgeons in 1999 entitled “Evidence-based clinical guidelines on preoperative evaluation in noncardiac surgery”. 


Despite the time immemorial concern, the practice of routine approach is still prevalent worldwide, the Philippines included.  Some of the reasons cited are medicolegal protection, habit, requirement of institution, ignorance of scientific evidences and unawareness of cost-effective management practice.


In the Philippines, practicing a selective approach in preoperative screening will be accompanied by a saving of about PhP 5,000 per patient.  This was extrapolated from a study in the Ospital ng Maynila Medical Center (OMMC) in 2001 in the Operasyon Bosyo (Operation Goiter) conducted by the hospital’s Department of Surgery.   Beside the financial savings, the other advantages of the selective approach consist of unnecessary pain from needle prick in blood collection; radiation exposure from routine chest x-ray; false alarms and mental anguish in cases of false-positive results; and inconvenience of going back and forth to the physician’s clinic, laboratory, and hospital (average of 5 times).


Knowing that majority of the routine screening preoperative laboratory examinations are NOT necessary and that there is a need to shift from the routine to the selective approach, how can change be brought about?


If you are a patient, ask your surgeon and anesthesiologist to request only tests that are really necessary.  For any test that you are being advised to undertake, you can ask these three questions:


  1. What are the chances that the test will yield a truly abnormal finding?
  2. In case the test yields an abnormal result, will there be a significant change in the plan of treatment? 
  3. Will there be a significant difference in the outcome of the operation if I don’t have the test done and if I have it done?


If the answers to the above three questions are small, none, and none respectively, then there is no need for the screening test.


For the medical insurers and hospital administrators as well as chairpersons of departments of surgery and anesthesia who are interested in instituting a shift from routine to selective approach, there is a model of change strategy that you can adopt or at least get some idea from. 


From 2001 to 2002, a change from a routine to selective preoperative screening investigations has been successfully effected and institutionalized in the Department of Surgery of Ospital ng Maynila Medical Center.  The change process consisted essentially of 4 chronological phases: 1) emergence of a surgeon-manager who could act as a change facilitator using an action research method; 2) development of a shared mission primarily between the staff of the departments of surgery and anesthesia and secondarily together with the staff of the nonsurgical departments and the hospital director/administrator; 3) pilot testing with documentation to convince all parties concerned of the benefits of the change; and 4) institutionalization of the change and constant monitoring against back-sliding. The change is being maintained by a memorandum of agreement between the Department of Surgery and Department of Anesthesia with authorization from the Hospital Director. 


Anybody interested in the details of how to effect the change, please call 524-60-61 and look for Dr. Vivian Enriquez or Dr. Rolando de Guzman.