Preoperative Screening Tests Research Articles

Unnecessary Preoperative Tests: The Hospital's Role

To the Editors: Macpherson and colleagues (1) question why routine preoperative screening tests often seem to be ordered unnecessarily and suggest that the ordering physicians might not be familiar...

Preoperative Laboratory Screening in Healthy Mayo Patients: Cost-Effective Elimination of Tests and Unchanged Outcomes

We reviewed the results of preoperative screening laboratory tests in asymptomatic healthy patients who underwent elective surgical procedures at our institution in 1988. Substantially abnormal results were found in 160 of 3,782 patients. All such abnormalities involved five tests: aspartate aminotransferase, glucose, potassium, platelet count, and hemoglobin. Thirty of the abnormal test results were predictable on the basis of the history or physical examination. The abnormal test result prompted further assessment in 47 patients. No surgical procedure was delayed, and no association was noted between adverse outcome and any preoperative laboratory abnormality. Because of our findings in this analysis and similar studies on specific tests from other institutions, we no longer require preoperative laboratory screening tests for healthy patients.

Preoperative Screening: Value of Previous Tests

To determine the frequency of tests done in the year before elective surgery that might substitute for preoperative screening tests and to determine the frequency of test results that change from a normal value to a value likely to alter perioperative management. Retrospective cohort analysis of computerized laboratory data (complete blood count, sodium, potassium, and creatinine levels, prothrombin time, and partial thromboplastin time). Urban tertiary care Veterans Affairs Hospital. Consecutive sample of 1109 patients who had elective surgery in 1988. At admission, 7549 preoperative tests were done, 47% of which duplicated tests performed in the previous year. Of 3096 previous results that were normal as defined by hospital reference range and done closest to the time of but before admission (median interval, 2 months), 13 (0.4%; 95% CI, 0.2% to 0.7%), repeat values were outside a range considered acceptable for surgery. Most of the abnormalities were predictable from the patient's history, and most were not noted in the medical record. Of 461 previous tests that were abnormal, 78 (17%; CI, 13% to 20%) repeat values at admission were outside a range considered acceptable for surgery (P less than 0.001, frequency of clinically important abnormalities of patients with normal previous results with those with abnormal previous results). Physicians evaluating patients preoperatively could safely substitute the previous test results analyzed in this study for preoperative screening tests if the previous tests are normal and no obvious indication for retesting is present.

Preoperative Hemostatic Assessment of the Adenotonsillectomy Patient

Intraoperative or postoperative hemorrhage in the patient who has undergone an adenotonsillectomy because of an unrecognized hemostatic defect may increase morbidity and can be potentially life-threatening to the patient in what should be a "routine" procedure. Preoperative identification of occult hemostatic abnormalities, coupled with perioperative management directed at correcting the effects of the defects, should serve to reduce the incidence of this distressful complication. Routine use of preoperative laboratory screening tests for this purpose has been discouraged recently as a result of concerns over cost-effectiveness and the low predictiveness of the tests for bleeding. Our experience with the routine use of a comprehensive hemostatic laboratory screening panel--which includes a bleeding time test--in the adenotonsillectomy patient population demonstrated that 11.5% of our patients had abnormal initial screening laboratory tests; these results were ultimately attributable to occult hemostatic defects. Clinical history, the universally recommended method of preoperative hemostatic assessment, failed to detect any previously unrecognized coagulation disorder. Laboratory screening improved preoperative detection of occult hemostatic defects and allowed for appropriate alterations in perioperative care. Our results with this approach are presented, along with illustrative case histories and a discussion of the current recommendations for preoperative laboratory screening of the hemostatic system, as found in a review of the literature.

Pursuit of abnormal coagulation screening tests generates modest hidden preoperative costs.

To measure the follow-up costs of preoperative coagulation screening tests, the authors studied 829 consecutive patients undergoing inpatient orthopedic surgery. The results of the initial prothrombin and activated partial thromboplastin time tests were divided into three groups: normal; abnormal above the hospital laboratory's upper limit of normal but below an "action limit"; and abnormal above an action limit. Patients with abnormal preoperative coagulation screening test results were matched on the basis of operative procedure and age with patients who had normal results. The matched groups of patients were compared according to preoperative length of stay and the cost of subsequent related preoperative testing. The average cost of follow-up preoperative testing for patients with abnormal screening test results was $5.05, compared with $0.58 for patients with normal screening results. The difference in average preoperative lengths of stay was not statistically significant. The attributable cost of evaluating an abnormal result added 3% to the cost of the initial coagulation screening program. This represents an average preoperative cost of $0.36 per patient in addition to the cost of the screening tests themselves.

Are routine preoperative laboratory screening tests necessary to evaluate ambulatory surgical patients? : H Johnson, S Knee-Ioli, et al. Surgery 1988; 104:639–645

Two hundred twelve consecutive adult patients undergoing a variety of ambulatory surgical procedures were studied prospectively to investigate whether routine preoperative urinalyses, complete blood counts (CBCs), and electrocardiograms (ECGs) were useful in determining the outcomes of their treatments. Urinalyses (U/As) were abnormal in 83 patients (39%); CBCs were abnormal in 19 patients (9%), and ECGs were abnormal in 140 patients (66%). The mean age of the patients was 64 plus or minus 12 years. The majority of patients with abnormalities determined by laboratory tests could have been predicted to have abnormalities on the basis of their histories and physical examinations. In this study, abnormalities indicated by laboratory tests did not influence preoperative cancellations, intraoperative or postoperative complications, or admissions to the hospital from the ambulatory unit after the surgical procedures. We conclude that routine preoperative screening laboratory tests have only a limited value in ambulatory surgical patients and recommend that they be either eliminated or replaced with less costly studies; for example, dipstick urinalyses for urinalyses, spun hematocrits for CBCs, and ECGs should be performed only if indicated by history and physical examination findings or if requested by an anesthesiologist.

SURGICAL MANAGEMENT Johnson, H., Jr., et al. Are routine preoperative laboratory screening tests necessary to evaluate ambulatory surgical patients? Surgery 104

SURGICAL MANAGEMENT Johnson, H., Jr., et al. Are routine preoperative laboratory screening tests necessary to evaluate ambulatory surgical patients? Surgery 104

Correlation of pathology observed in double contrast arthrotomography and arthroscopy of the shoulder

Correlation of double contrast arthrotomography (DCAT) of the shoulder and arthroscopic surgery diagnostic results have been undertaken in 55 patients with persistent shoulder pain or involuntary shoulder instability. During the period March 1984 to December 1986, 55 patients underwent DCAT followed by videotaped diagnostic shoulder arthroscopy. The primary indication for DCAT was persistent pain in 36 patients and instability in 17 patients. DCAT was performed according to the method of El-Khoury and Albright, and all arthroscopies were performed in a similar fashion by the senior author (HJS). Both tests were reviewed separately, retrospectively, and their results were correlated. For combined (anterior and posterior) labral pathology, the sensitivity/specificity for the instability group was 0.91/0.91, respectively; sensitivity/specificity for the pain group was 0.63/0.94. DCAT accurately depicted the status of 76% of anterior labrums and 96% of posterior labrums. For complete rotator cuff tears, sensitivity/specificity was 1.0/0.94. The status of a complete rotator cuff tear was accurately depicted in 91% of patients. Partial rotator cuff tears were missed in 83% of patients by DCAT. The presence or absence of loose bodies was accurately represented by 96% of DCAT. Arthroscopy showed that 71% of the instability patients had a labral tear, compared with 44% of the pain patients. Rotator cuff pathology was present in 12% of instability patients and 42% of pain patients. These findings indicate that DCAT may be a conditionally reliable test in the diagnosis of shoulder instability. DCAT must be considered inconclusive, however, in the painful shoulder without instability. Its usefulness as a preoperative screening test is discussed, and a diagnostic algorithm is presented. DCAT does not equal the diagnostic accuracy of shoulder arthroscopy.

The Value of Preoperative Screening Investigations in Otherwise Healthy Individuals

• To assess the value of routine screening preoperative investigations in an otherwise healthy surgical population, the charts of 2570 patients undergoing cholecystectomy in two university teaching hospitals were reviewed. Of these, 1010 patients who were believed to be free of active disease other than cholelithiasis were selected for further study. Preoperative screening investigations were assessed in terms of frequency of use and abnormalities detected. The predictive values of these tests were analyzed and compared with information obtained from the history and physical examination. The frequency with which action was taken because of abnormal test results was also determined. Of the 5003 preoperative screening tests performed, abnormal results were obtained in 225. Of these, 104 were of potential importance. Action resulting from these abnormalities occurred in 17 cases. In only four patients could a conceivable benefit have arisen from a preoperative screening test. When compared with the results of the history and physical examination, routine preoperative investigations provided little further information that altered management in otherwise healthy surgical patients undergoing cholecystectomy. ( Arch Intern Med 1987;147:1101-1105)

The Value of Preoperative Screening Investigations in Otherwise Healthy Individuals

To assess the value of routine screening preoperative investigations in an otherwise healthy surgical population, the charts of 2570 patients undergoing cholecystectomy in two university teaching hospitals were reviewed. Of these, 1010 patients who were believed to be free of active disease other than cholelithiasis were selected for further study. Preoperative screening investigations were assessed in terms of frequency of use and abnormalities detected. The predictive values of these tests were analyzed and compared with information obtained from the history and physical examination. The frequency with which action was taken because of abnormal test results was also determined. Of the 5003 preoperative screening tests performed, abnormal results were obtained in 225. Of these, 104 were of potential importance. Action resulting from these abnormalities occurred in 17 cases. In only four patients could a conceivable benefit have arisen from a preoperative screening test. When compared with the results of the history and physical examination, routine preoperative investigations provided little further information that altered management in otherwise healthy surgical patients undergoing cholecystectomy.

Urodynamic appraisal of the marshall-marchetti test in women with stress urinary incontinence

To determine the reliability of the Marshall-Marchetti test as a diagnostic and prognostic preoperative screening test for stress urinary incontinence, the changes observed in urethral pressure profiles under resting and stressful situations were recorded and compared following varying degrees of elevation of the urethra and the urethrovesical junction. The characteristic similarity of changes was evident in the functional profile length, urethral closure pressure, and cough pressure profile of the urethra during performance of the Marshall-Marchetti test and intentional urethral occlusion. This study clearly invalidated the Marshall-Marchetti test by objectively demonstrating that the Marshall-Marchetti test restored continence under stress of coughing by occluding the urethra and the urethrovesical junction.

The Bleeding Time as a Preoperative Screening Test

Department of Medicine and Pathology, Northwestern Memorial Hospital and Northwestern Memorial Hospital, and the Atherosclerosis Program, Rehabilitation Institute of Chicago, Chicago, Illinois

The Bleeding Time as a Preoperative Screening Test

The Bleeding Time as a Preoperative Screening Test

The bleeding time as a preoperative screening test

To examine the benefit of determination of the bleeding time as a preoperative screening test, the medical records of all patients who had a prolonged bleeding time during a six-month period were reviewed. At Northwestern Memorial Hospital, where the bleeding time test is part of the presurgical panel, 1,941 bleeding time determinations were performed during six months. Prolonged bleeding times were recorded in 110 preoperative patients, of whom 83 (75 percent) had bleeding risk factors, including drug ingestion, thrombocytopenia, and azotemia. In these patients, the bleeding time ranged unpredictably from 10 to more than 20 minutes. However, of the 27 patients without apparent risk factors, only two had bleeding times of more than 20 minutes. This small number probably does not justify the routine use of the test In all preoperative patients. Rather, the test should be used selectively for those subjects who, on the basis of history or laboratory evidence, are suspected of being at risk of hemorrhage. Moreover, even In these patients, prolongation of the bleeding time may not always be associated with excessive surgical blood loss.

Prothrombin and partial thromboplastin times as preoperative screening tests : Eisenberg JM, Clark JR, Sussman SA. Arch Surg 117:48, 1982

Prothrombin and partial thromboplastin times as preoperative screening tests : Eisenberg JM, Clark JR, Sussman SA. Arch Surg 117:48, 1982

Evaluation and management of coagulation disorders in elective surgical patients

This is a review of coagulation disorders in elective surgical patients. The study represents both a personal experience in unusual bleeding and clotting disturbances and, in addition, a 15-year review of unique problems evaluated by the Coagulation Department of a local general hospital. Of this group of cases, 17 were selected to illustrate the purpose of this report. Potential "bleeders" due to coagulation defects may be missed preoperatively both by history and by commonly accepted screening tests. The incidence of this situation is fortunately rare, but unfortunately this dulls the likelihood of early diagnosis with the initiation of specific treatment measures. The limitations of preoperative screening tests were apparent and should not be considered a fail-safe detector of coagulation disorders. Qualitative and quantitative factor assay are the cornerstone for accurate diagnosis and a guide for specific replacement therapy. Although most surgeons will never have an in-depth knowledge of hematology, the importance of having some fundamental awareness is apparent. This study encourages surgeons not to take the hemostatic mechanism for granted, and to see the need for understanding hematologic diagnosis and treatment.

A theoretical assessment of the value of the PTT as a preoperative screening test in adults.

A theoretical assessment of the value of the PTT as a preoperative screening test in adults.

Analysis of simple pulmonary function screening tests in preoperative assessment before lung resection for bronchogenic carcinoma.

Simple pulmonary function screening tests were performed prospectively in a group of patients with carcinoma of the bronchus being evaluated for lung resection. Of the 22 who subsequently had a resection performed, 7 suffered post-operative ventilatory difficulties unrelated to technical surgical complications. By analysis of combinations of variables, it was possible to separate significantly the complication group from the non-complication group. This was not possible using one variable alone. The method of empiric determination of values which produce maximum separation is described and contrasted with the more statistically acceptable technique of discriminant analysis. With the latter it is possible to incorporate information from any number of variables and to achieve greater definition of the two groups. It is proposed that such an analysis might provide the means for more valid scientific assessment of simple pre-operative screening tests than is usually employed.

A preoperative screening test for chronic back pain patients

The authors describe a quickly administered screening test designed to aid in the diagnosis of patients with chronic pain complaints and to help predict the outcome of contemplated surgery. The test was applied retrospectively to 315 patients and was 83% accurate in selecting out those who had an organic basis for their pain. Two thirds of the patients who had negative physical findings scored in a range suggesting the absence of an organic cause for the pain. Preliminary results from a prospective trial of the test have confirmed its usefulness.

Surgical Treatment of Renovascular Hypertension Associated with Bilateral Renal Artery Stenosis

We report on 15 patients operated upon for renovascular hypertension associated with bilateral renal artery stenosis. Followup has been for 1 to 12 years. Four of 5 patients with positive split renal function studies and 3 of 5 patients with positive renal vein renin assays underwent unilateral operations on the positive side. All of these patients were cured or improved. The guide for unilateral operations in hypertensive patients with bilateral renal artery stenosis by angiography was the physiological information obtained from the preoperative screening tests, especially the plasma renin activity ratios of the 3 different veins and the split renal function studies.