Part of "Chapter 6 - Preoperative Care"
Prior to the era of evidence-based medicine most patients undergoing gynecologic surgery were assessed by a thorough history and physical examination followed by a battery of laboratory tests, the purpose of which was to detect a medical disease or defect that could adversely affect surgical outcome. These tests were accomplished on almost all patients, irrespective of age or concurrent medical or surgical
pathologies, and might include: (a) blood count with hemoglobin and hematocrit; (b) urinalysis; (c) coagulation studies; (d) chemistry panel; (e) chest x-ray; and (f) electrocardiogram. This relatively
universal use of “routine” preoperative testing has not proven to be beneficial in terms of good patient care and, additionally, it has added significantly to the cost of medical care. In one study an average of 72.5%
of preoperative tests ordered by surgeons were considered unnecessary based on a review of the
patient's history and physical examination. This same study suggested a medical care savings of between 4 and 10 billion dollars per year in the United States by eliminating these unnecessary tests with no adverse effect on outcome.
Over the last 10 years data has surfaced allowing gynecologists to better assess needed preoperative tests from those that in the past were labeled as “routine” tests. Because of information such as this and because of pressures from MCOs, the volume of preoperative testing has been reduced. With this reduction in the ordering of unnecessary tests, however, comes a reduction in the ordering of necessary tests. This finding emphasizes the need to accurately differentiate between indicated preoperative testing and the past practice of routine blanketed testing of gynecologic patients preparing for surgery. A large portion of the remainder of this chapter focuses on the best case series data to help guide the
gynecologist when ordering appropriate preoperative tests
based on the individual patient's history and physical examination.
Key to the understanding of appropriate preoperative testing is an understanding of: (a) the risk category of the patient; and (b) the degree of complexity of the planned surgery. The risk category of any
preoperative gynecology patient may be divided into one of six different classes as established by the American Society of Anesthesiologists (Table 6.1). The degree of complexity of the planned surgery may be divided into one of three separate types (Table 6.2). Therefore, preoperative testing should be planned around the assessed risk of the patient based on her age, history and physical examination, and the degree of complexity based on the invasiveness of the proposed surgery. Therefore, current data as well as experience suggest that, rather than a routine set of tests, all preoperative testing should be
inextricably related to the type and complexity of the proposed gynecologic surgery and to the presence of the confounding medical or surgical condition.
TABLE 6.1. Classification of Physical Status, Established by the American Society of Anesthesiologists
Class Description
P1 A normal healthy patient
P2 A patient with mild systemic disease
P3 A patient with severe systemic disease
P4 A patient with severe systemic disease that is a constant threat to life
P5 A moribund patient who is not expected to survive without the operation
P6 A declared brain-dead patient whose organs are being removed for donor purposes
From: ASA Manual for Anesthesia Department Organization and Management, American Society of Anesthesiologists, Park Ridge, Ill., 1995, with permission.
TABLE 6.2. Types of Surgical Procedures for Which Anesthesia May Be Administered
Type General Definition Special Examples
Type A
Minimally invasive procedures that have little potential to disrupt normal physiology and are associated with only rare periprocedural
Moderately invasive procedures that have a modest or intermediate potential to disrupt normal physiology. These procedures may require blood administration, invasive
monitoring, or postoperative management in a critical care setting.
From: Roizen MF, Foss JF, Fischer SP. Preoperative evaluation. In: Miller RD, ed.
Anesthesia, 5th ed. Philadelphia: Churchill Livingstone, 2000:843, with permission.
Asymptomatic Patients
In an extensive review of currently available evidence on the value of routine preoperative testing in healthy or asymptomatic patients, Monro (1997) found that there were no controlled trials assessing the value of basic tests previously thought to be essential in presurgical evaluation and care. These tests included chest x-ray, electrocardiogram, blood counts and hemoglobin, coagulation studies, blood chemistries, and urinalysis. The authors further noted that all currently available evidence on preoperative testing of healthy or asymptomatic patients came only from case series studies. After reviewing all of the available case series data they concluded that the power of preoperative tests to predict adverse
postoperative outcomes in asymptomatic patients is either weak or nonexistent.
Conclusions such as this have resulted in: (a) a marked reduction in the recommendation of routine testing; and (b) the suggestion that the amount of routine testing of preoperative healthy asymptomatic patients be related to the patient's age. Currently, in this category of patients, it has been recommended that a hemoglobin or hematocrit be accomplished on all patients over the age of 6 months; an
electrocardiogram (ECG) on all patients over the age of 40; and a blood urea nitrogen (BUN) test and a glucose test on all patients over the age of 65. Additionally, a pregnancy test should be accomplished on
all reproductive-age women who are at risk of early pregnancy (sexually active, no contraception, or questionably effective contraception) (Table 6.3).
TABLE 6.3. Recommended Preoperative Testing for Healthy Asymptomatic Gynecologic Patients
Above Age 6 Months Above Age 40a Above Age 65a
Hct or Hbg Hct or Hbg Hct or Hbg
ECG ECG
BUN/glucose
All Women in Reproductive Age, Sexually Active, Questionable Contraception
Pregnancy test
aRecommendation of MF Roizen, Preoperative evaluation. In: Miller RD, ed. Anesthesia, 5th ed. Philadelphia: Churchill Livingstone, 2000:854, with permission.
Symptomatic Patients and Patients with Medical or Surgical Pathologies or Defects
Women considered for gynecologic surgery who are symptomatic and/or have other medical or surgical pathologies or defects must be considered in a different light from asymptomatic, healthy women during their preoperative evaluation and testing. Preoperative testing should be accomplished to determine the current status of medical or surgical pathologies and provide data on the potential effect that the
compounding problem will have on the outcome of the proposed surgery. This would allow, if possible, for necessary medical correction or improvement of the problem prior to surgery in an attempt to minimize
adverse outcomes of surgical intervention.
Despite the lack of an evidence-based, preoperative evaluation plan to guide preoperative testing, experience supports adopting a diagnosis-based preoperative testing protocol when planning any gynecologic surgery. A number of diagnosed-based or clinical condition-based protocols have been suggested. Because the diagnosed-based preoperative testing evaluation recommended by Fischer considers both clinical outcomes as well as cost-effectiveness, it is most appropriate in the preoperative evaluation of gynecologic patients who are other than healthy and asymptomatic (Table 6.4). This approach links necessary preoperative laboratory and imaging testing with concurrent medical disease, including cardiovascular, pulmonary, and endocrine pathologies, as well as with malignancies, and the use of many common drug therapies.
TABLE 6.4. Diagnosed-based Preoperative Testing
Preoperative Diagnosis
ECG CXR Hct/Hb CBC Lytes Renal Glucose
Cardiac disease
MI history X ±
Stable angina X ±
CHF X ± ±
HTN X ± Xa X
Chronic atrial fib X
Periph vascular disease
X
Valvular heart disease X ±
Pulmonary disease
Emphysema X ±
Asthma
Chronic bronchitis X ± X
Diabetes X ± X X
Hepatic disease
Infectious hepatitis
Alcohol/drug induced
Tumor infiltration
Renal disease X X X
Hematological disorders
X
Coagulopathies X
CNS disorders
Stroke X X X X
Seizures X X X X
Tumor X X
Vascular/aneurysms X X
Malignancy X
Malignancy X
Hyperthyroidism X X X
Hypothyroidism X X X
Cushing's syndrome X X X
Addison's disease X X X
Hyperparathyroidism X X X
Hypoparathyroidism X
Morbid obesity X ± X
Malabsorption/poor nutrition
X X X X X
Select drug therapies
Digoxin (Digitalis) X ±
Anticoagulants X
Dilantin
Phenobarbital
Diuretics X X
Steroids X X
Chemotherapy X
Aspirin/NSAID
Theophylline
X = Obtained.
± = Consider.
aPatients on diuretics.
bPatients on digoxin.
cPatients on theophyilline.
From: Fischer SP. Cost-effective preoperative evaluation and testing. Chest 1999;115:98S, with permission.