7 Pre-Op Tests You Can Do Without

For approximately four decades, prompted by fear of falling below standards or not exercising good clinical judgment, surgeons have ordered a battery of pre-op tests on every patient prior to surgery. We believe that this practice should change. The vast majority of pre-op tests are irrelevant when it comes to patient outcomes. Also, they generally do not enable us to modify the perioperative management to enhance the surgical outcome. Numerous recent studies support this concept, including one large study of patients undergoing cataract surgery,1 one of the most common outpatient surgical procedures. The study reported that the patients who underwent a series of routine, preoperative tests fared just as well as those who did not receive the tests.

Preoperative testing can have negative consequences. If the results are not pursued, they can increase rather than reduce legal liability-in fact, between 30 and 60 percent of all unexpected abnormalities detected by preoperative laboratory tests are not actually noted or investigated before surgery, creating increased legal liability.

Unnecessary lab tests also waste millions of dollars. In one study,2 the author determined that annual patient charges would have been reduced by more than $400,000 at his facility if lab tests for all surgical outpatients had been ordered as dictated by the history and exam rather than by either routine or by arbitrary criteria.

Finally, unneeded testing can also cause delays in surgery and create hassles for the patient, reducing patient satisfaction.

In our primarily orthopedic ambulatory surgical center, we do not order routine pre-operative testing; we test only if we identify high-risk medical conditions that may have an impact on the perioperative outcome. We test only when the history or a finding during a physical examination would have indicated the need for a test even if surgery had not been planned. In this article, we will explain why we test less, discuss each of the traditional pre-operative tests, and detail when we do and do not order them.

1. Coagulation Studies
Facilities typically administer coagulation tests, which include PT (prothrombin time), PTT (partial thromboplastin time), platelet count, and bleeding time, to determine whether the patient has a history of abnormal bleeding or a bleeding disorder, such as hemophilia or von Willebrand's disease, which could lead to hemorrhage during surgery.

Unfortunately, numerous studies have proven coagulation tests to be poor at detecting unsuspected bleeding disorders. One such study3 examined patients who bled after bronchoscopy with biopsy. These patients had normal coagulation parameters and no clinical risk factors-a coagulation profile wouldn't have helped the surgeons prevent or manage the bleeding. Another study of 1,000 patients4 found that patients who did have abnormal coagulation test results had identifiable risk factors for bleeding, which could have been picked up with a complete history and physical exam.

Even for more serious disorders, like hemophilia or von Willebrand's disease, routine coagulation tests are of little use. The incidence of hemophilia in men without a family history of the disease or a history of major trauma or surgery is only 0.0025 percent,5 making it exceedingly unlikely that we would fail to pick this up in a thorough history and physical. The PTT test is rather insensitive to both hemophilia and von Willebrand's, and even in the rare case that you do have a patient with this condition, the chance of fatal hemorrhage is slim.

We order coagulation tests only in patients who are receiving anticoagulant therapy or who have a history of abnormal bleeding, severe liver disease, or thrombocytopenia (a condition where there is an abnormally small number of platelets in the circulating blood). If you take a thorough personal and family history and ask the patient if he or she bruises or bleeds easily, you are likely to rule out any of these relevant disorders without a blood test.

2. Chest X-rays
Some facilities require that all patients over 55 undergo a preoperative chest X-ray. It's true that X-rays often do find heart or lung abnormalities, but the chances that these findings will be relevant in the anesthetic or surgical management are extremely small.

As with all pre-op tests, if you do find any abnormal results on the X-ray, you are obligated to perform secondary tests, unnecessarily delaying the surgery. If you fail to study the results and follow up, you expose yourself to potential liability. We were involved in a urology case years ago where the surgeon ordered an X-ray, but proceeded with the surgery without examining the film. The patient did very well, but later on was diagnosed with lung cancer. When it was discovered that the cancer could have been detected on the original X-ray, the patient sued the surgeon, anesthesiologist, radiologist, and the outpatient surgery center.

The point is not to avoid ordering X-rays, but rather to order them selectively and to use them when you do order them. Ask whether the patient has a history of severe lung disease, or coughs frequently. If the answers to any of these questions are "yes," consider ordering a chest X-ray and carefully evaluating the results. If the patient is asymptomatic, forego it.

3. EKGs
If you see many elderly patients and order EKGs for all of them, you'll find that most of them have abnormal test results-in fact, one study showed abnormal pre-op EKGs in 43 percent of 750 outpatients.6 The question is, is this information useful? In this same study, there were 12 adverse perioperative cardiovascular events, and the preoperative EKG may have been predictive in only six of these cases. Incidentally, pre-op questionnaires are also poor predictors of cardiovascular complications.

It's unfortunate, but unless the patient's history suggests significant heart disease or arrhythmia, EKGs will provide very little information that will affect your management of the patient. We suggest ordering EKGs only when the history or physical exam suggests it.

4 & 5. Blood Crossmatching and Hemoglobin/Hematocrit
Most outpatient surgical procedures do not involve significant blood loss, so these two tests are usually unnecessary. If the patient has a history of anemia that may affect surgical management, you should be able to pick this up during the history and physical ????-??? severe anemia occurs in less than 1 percent of asymptomatic patients. If the patient is anemic, a baseline hemoglobin/hematocrit may be warranted if you expect the procedure to involve moderate blood loss.

6. Urinalysis
Urinalysis detects urinary tract infections and screens for undiagnosed renal disease. There is no data to suggest that either condition would affect most outpatient surgeries, so we never order this test.

7. Chemistry Testing
Routine chemistry testing, which includes serum electrolyte determinations, tests of renal function, and serum glucose levels, are all generally reported together as part of a chemistry panel. In patients undergoing non-selective, routine pre-op chemistry screenings, unsuspected abnormalities are only found 1 to 0.2 percent of the time,7 and there is no evidence to suggest that these abnormalities alter anesthetic or surgical treatment or lead to an adverse outcome. Some physicians have suggested that a test of renal function may be useful in patients over age 40 because of the need to adjust dosages of some medications perioperatively, but there are no data to support this recommendation. In any case, mild impairments in renal function generally have no bearing on general anesthesia or conscious sedation.

The Exception-Pregnancy Testing
Even though pregnancy itself does not necessarily contraindicate surgery, we do suggest performing a pregnancy test in all potentially fertile females if you plan to use either general anesthesia or fluoroscopy during the case.

Ordering preoperative tests selectively confers several benefits. It reduces unnecessary OR delays, shields the doctor and facility from assuming legal risk, and adds to patient satisfaction, since very few patients enjoy taking time out of their schedule to undergo pre-op testing. Physicians feel that being associated with a hospital brings more credibility than if they were building the center alone. Very successful independent centers do exist, but physicians generally feel that if the hospital is involved with the project that they have a greater sense of success, both financially and politically

We recommend that you start every patient with a thorough history and physical examination, only order tests when absolutely necessary, and be sure to follow up and document on the results of any of those tests. Make a list of abnormal results, or "panic values," available to your office staff so they can immediately contact surgeons about results that fall outside normal ranges. Finally, have staff members document all phone calls to patients as well as management decisions based on test results. This common-sense approach should you give you all the information you need to provide the highest standard of care.

Certificate of need (if one is required).
The CON process in many states is very complicated. Often a hospital may have an existing CON that it can sell to the new partnership or can "trade" ORs with the new venture. This can often save years and hundreds of thousands of dollars in a project. The majority of physicians feel that the hospital can make or break their approval process.