This chapter should be cited as follows:
Walton, L, Glob. libr. women's med.,
(ISSN: 1756-2228) 2008; DOI 10.3843/GLOWM.10035
Under review - Update due 2017

Preoperative Management

Leslie A. Walton, MD
Professor, Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina

INTRODUCTION

The approach to gynecologic patients about to undergo surgery is laden with challenges, because the arena in which surgeons operate is beset by problems involving the delivery of quality care, the accommodation of patient input, and dwindling health care dollars. In addition, the technological advances in medical diagnostic systems have interposed a conundrum when a compromise in health care cost is sought. Furthermore, there is a gradual but continual shift in the quantitation of health care, with emphasis redirected from long-term to short-term care and an increasing proportion of care moving from an inpatient to an outpatient setting. The problems in administering this care are compounded by a redistribution in the patient population from a young healthy group to an increasingly larger cadre of older patients, many of whom are encumbered by diseases of aging. In the continuing squabble about the cost of surgical service, physicians are constantly being pressured to minimize their charges for services rendered. It is in this setting that contemporary gynecologists operate as they prepare to deliver dynamic preoperative care to their patients.

The most critical aspect of the preoperative assessment centers on the patient herself. Surgical procedures on the female genital tract create conflicting feelings about femininity in patients. In addition to their concerns about a successful technical outcome, patients express worries about physical rehabilitation, cosmetic result, impairment in psychosocial functioning, and their general return to well-being. The operative evaluation must address most if not all of these problems in a realistic and positive way. The evaluation should aim to provide patients with a comprehensive understanding of the upcoming process. Although a successful outcome is almost mandated by modern advances in contemporary medicine, setbacks are encountered and must be anticipated and discussed, in view of the legal turbulence that pervades today's medical practice.

HISTORY AND PHYSICAL EXAMINATION

A comprehensive review of a patient's historical data is an essential first step. Impact of the underlying disease on other organ systems is sought. The presence of an older population with subtle organ system deterioration mandates a careful review of cardiac, pulmonary, and renal functioning in addition to the routine evaluation of the other organ systems. For example, a history of nocturnal pedal edema and mild dyspnea on activity will alert a physician to delve deeper into a patient's cardiac functioning. While emphasizing the patient as a whole, further questioning should aim to verify the working diagnosis and relegate meaningful alternative diagnoses to a lesser role.

The history taking should inquire into a patient's drug intake to look for compounding effects of drugs on anesthesia or the surgical process. A history of chronic use of diuretics alerts clinicians to look for hypokalemia and even hyperglycemia to thwart the deleterious effect of hypokalemia on anesthetic action, cardiac function, and acid-base balance. A search for allergic reactions to drugs is important. The use of recreational drugs and their progressively worsening sequelae should be investigated.

A review of previous studies updates physicians on the improvement or deterioration of existing disease conditions and helps streamline the ordering of additional testing. For example, a history of a previous surgical procedure obligates a physician to obtain all data regarding reaction to anesthesia, extent of surgery, final diagnosis, and accompanying follow-up.

The physical examination should confirm or reaffirm the working diagnosis. A patient admitted with an ovarian cyst requires a preoperative examination to confirm that the cyst has not ruptured or was not confused with an unusual differential diagnosis such as a full bladder or an intermittent cecal dilatation. In addition, during the physical examination, a search is instituted for factors that will impede the smooth administration of anesthesia or complicate the surgical procedure. For example, tracheal deviation due to a goiter might complicate intubation and pendulous breasts might signal the need for careful postoperative pulmonary monitoring. A cardiac murmur might mandate echocardiographic studies or signal the need for prophylactic antibiotic administration.

The abdominal and pelvic examinations are critical to the preoperative process. The working diagnosis must be confirmed. Findings are sought to indicate whether the disease process is stable, has improved, or has worsened. Attention is directed to the extent of surgery, and any variations in technique or extent of surgery will require thought and discussion with the patient and her significant others.

A thorough and complete examination is reassuring to a patient and her physician. The assurance to the patient that organ system evaluation is satisfactory fortifies her outlook as she approaches the operation.

ANESTHESIA EVALUATION

The anesthesiologist's presurgical visit and evaluation are important in preparing patients for the operating room. The method of anesthesia and the agents available can be discussed. The use of epidural anesthesia or other modalities for postoperative pain relief should be discussed. In addition, the use of patient-controlled analgesia can be explored. This special evaluation by a major member of the surgical team reinforces the breadth of attention to a patient's care and strengthens her rapport with this team member.

An assignment of surgical risk can be made using the American Society of Anesthesiology physical status classification (Table 1).1 The letter E is added to any of the classes when an emergency operation is performed. Anesthesia and surgical morbidity increase as the physical status increases from status I through status V.

TABLE 1. American Society of Anesthesiology Physical Status Classification


Physical Status

Patient Category

I

A normal, healthy patient

II

A patient with mild to moderate systemic

 

 disease (e.g., anemia, morbid obesity)

III

A patient with severe systemic disease that

 

 limits activity but not to the point of

 

 incapacitation (e.g., healed myocardial

 

 infarction, diabetes with vascular complications)

IV

A patient with incapacitating systemic

 

 disease that is life threatening (e.g., ad-

 

 vanced hepatic or renal insufficiency)

V

A moribund patient who is not expected to

 

 survive (e.g., major cerebral trauma,

 

 massive pulmonary embolus)

(American Society of Anesthesiology physical status classification. Anesthesiology 49:239, 1978)

CONSIDERATIONS INVOLVING THE CARDIOVASCULAR SYSTEM

Cardiac Considerations

Preoperative evaluation of gynecologic patients should proceed far beyond the routine auscultation of the heart and palpation of peripheral pulses. Routine history and physical examination will suffice in young, healthy, asymptomatic patients with a benign cardiac history. However, older patients or patients with pertinent physical findings will require more detailed questioning and a rigid, systematic cardiac evaluation.

The findings in a study by Goldman and colleagues have served as a basis for estimating cardiac risks.2 These researchers examined the cardiac status of 1001 patients who were over the age of 40 and were undergoing noncardiac procedures. The lower abdomen and retroperitoneal and pelvic areas were involved in 131 operations. Nine independent correlates that were predictive of life-threatening cardiac complications were identified and assigned a point system (Table 2).

TABLE 2. Goldman's Correlates Predicting Cardiac Risk


Correlate

Points

1. Age greater than 70 years

5

2. Myocardial infarction in the previous 6 months

10

3. S3 gallop or jugular venous distention

11

4. Important aortic stenosis

3

5. Rhythm other than sinus or premature atrial contraction

7

6. More than five premature ventricular contractions per minute documented anytime before the operating room

7

7. Poor general medical condition (e.g., elevated blood urea nitrogen, bedridden patient)

3

8. Intrathoracic, intraperitoneal, or aortic operation

3

9. Emergency operation

4

(Multifactorial index of cardiac risk in non-cardiac surgical procedures. N Engl J Med 297:845, 1977)

Four risk categories were then condensed from these risk factors and assigned to a numerical class (Table 3). Serious cardiac or other morbidity was correlated with the point system.

TABLE 3. Goldman's Risk Index


Class

Points

Cardiac Deaths or Life-ThreateningComplications (%)

1

0 to 5

0.9

2

6 to 12

7

3

13 to 25

14

4

greater than 26

78

Patients with a risk index of 26 or more points should undergo only life-saving surgery. Patients with index scores of 13 to 25 probably exhibit sufficient cardiac risk to warrant routine preoperative cardiac evaluation.

Assessment of cardiac risk is important because of the physiologic and metabolic responses to surgery. In the perioperative period, the stress of impending surgery results in an increase in sympathetic activity that can be documented by increased excretion of urinary catecholamines. Increased release of adrenocorticotropic hormone also occurs with elevation of plasma cortisol levels. Increased antidiuretic hormone secretion is also common. As a result, patients can exhibit mild elevation of blood pressure or blood glucose and can retain fluid.

Second, all anesthetic agents, especially halothane and nitrous oxide, depress myocardial function. Some of these agents are mild vasodilators. With decreased myocardial contractility and peripheral pooling, there is a decrease in intravascular volume and cardiac output. Patients with underlying heart disease or arteriosclerotic disease are at risk for worsening cardiovascular sequelae. Significant degrees of hypoxemia are often encountered after surgery, and if an existing myocardial insult is present, cardiac imbalance can be aggravated by this decrease in oxygen tension. The major cardiac risk involves myocardial circulatory compromise.

The incidence of perioperative infarction is about 0.15%, rising to 2% if routine postoperative electrocardiograms are used to assist in diagnosing clinically silent myocardial infarctions.3 Patients with a previous myocardial infarction are at increased surgical risk. These patients have a 6.6% chance of having a second postoperative infarction.4 Advances in anesthesia care did not improve the morbidity in these patients when the study was repeated 6 years later.5 If surgery is performed within 6 months of an infarction, patients are at increased risk for reinfarction. Experts therefore advise postponement of elective surgery for at least 6 months if a patient has suffered from either a transmural or nontransmural myocardial infarction. Unstable angina of less than 3 months duration is an absolute contraindication to noncardiac surgery except in a dire emergency situation.

Other cardiac conditions may or may not predispose patients to operative risks. Patients with stable angina pectoris without previous myocardial infarction are not at increased surgical risk.6 Patients with documented coronary artery disease involving three vessels should be considered for bypass surgery before major noncardiac surgery. If congestive heart failure and appropriate treatment result in “compensated” cardiac function, no increased risk exists for the patient when noncardiac surgery is performed. Patients with fixed cardiac output secondary to diseases such as tight aortic or mitral stenosis are at increased risk. They require cardiac consultation before surgery. The occurrence of more than five premature ventricular contractions per minute documented at any time before surgery results in an increased cardiac risk for a patient.2 Although lidocaine is used preoperatively in these patients, it is not known whether administration of this drug decreases the cardiac complications.

Hypertension and Antihypertension Medication

Attention to blood pressure readings of gynecologic patients is important because 28% of noncardiac patients being readied for surgery either have hypertension, are discovered to be hypertensive, or are undergoing therapy for hypertension.7 Approximately 4% of patients with hypertension can have elevated blood pressure as a result of using oral contraceptives.8 Accordingly, elective surgical procedures should be postponed until blood pressure readings are normalized. However, it has been shown that patients tolerate surgery quite well without cardiac sequelae when they have stable, controlled diastolic pressures not exceeding 110 mm Hg.

During induction of general anesthesia, the systolic blood pressure often rises by 20 to 45 mm Hg at the time of intubation. This phenomenon is encountered in 6% of patients with normal blood pressure and in 17% of patients with a documented history of hypertension. Wide blood pressure variations and the presence of depressed myocardial contractility due to anesthetic agents can contribute to cerebral or myocardial ischemia and other organ compromise.

One of the major problems with hypertensive patients involves the continuation of medication before surgery. The old dogma that most medications should be discontinued before surgery is no longer tenable. The continuation of antihypertensives was thought to interact with anesthetics and create hypotension. It is now believed that antihypertensive medication can be taken up to the time of surgery and resumed early in the postoperative phase.

Certain hypertensive and cardiac medications and their effects need to be addressed. Propranolol should be continued both preoperatively and postoperatively. If it is withdrawn, patients develop a hypersensitive reaction to any adrenergic stimulation. Surgical stimulation releases catecholamines, with resultant arrhythmias, angina, and myocardial infarction. Digitalis should be continued preoperatively. Bradyarrhythmias occasionally occur intraoperatively in patients on digitalis, but the arrythmias are probably due to unstable digitalis levels. Nitroglycerin should be continued in some appropriate form.

Thiazide diuretics may be continued up to the night before surgery and resumed when oral intake is feasible. Three hypertensive drugs--amethyldopa, propranolol, and hydralazine--are available as both oral and intravenous preparations. Propranolol can be continued preoperatively and postoperatively. The same recommendation holds for the other two drugs, although appropriate dose titrations need to be made.

Clonidine, a drug with central sympatholytic action, presents a special problem in that abrupt discontinuation of this drug results in severe rebound hypertension. In general, clonidine should not be discontinued, and anesthesiologists should be notified so that appropriate intraoperative intervention can be planned.

CONSIDERATIONS INVOLVING THE RESPIRATORY TRACT

Routine gynecologic patients rarely present with obvious pulmonary problems. Young patients without overt pulmonary symptoms can have pulmonary compromise due to diseases such as asthma or sarcoidosis. In addition, smoking, job-related pollutants, or medication can result in compromised pulmonary function without gross symptoms. However, careful review of pulmonary functioning might indicate some compromise of function.

Pulmonary volumes can undergo changes as a result of operative procedures. Mean arterial oxygen tension (PaO2) decreases from a preoperative value of 88 mm Hg to about 63 mm Hg immediately after surgery.9 Residual volume, functional residual capacity, vital capacity, and expiratory reserve volume all are decreased postoperatively. Vital capacity may be depressed by as much as 45% within the first 2 days postoperatively. This decrease is encountered primarily in patients undergoing thoracic and upper abdominal surgery and is less in patients undergoing pelvic procedures.

Atelectasis and bronchitis are the two most common postoperative complications. They occur in about 10% to 20% of the normal healthy adult population. However, the incidence of atelectasis after lower abdominal surgery is more in the 10% range. Cognizance of these complications mandates preoperative planning of breathing exercises.

Many factors predispose patients to pulmonary complications. Among these factors are the following:

  1. Older age
  2. Obesity, especially morbid obesity
  3. Smoking
  4. Known pulmonary disease
  5. Sputum production exceeding 2 ounces/day9

The presence of any of these factors indicates the need for pulmonary function testing to search for compromise of function.

Simple screening tests for respiratory function include arterial blood gas determinations and pulmonary function studies. Preoperative hypoxemia with a PaO2 less than 50 mm Hg and/or arterial carbon dioxide tension (PaCO2) greater than 15 mm Hg constitutes significant contraindications to pelvic surgery. Similarly, mean breathing capacity less than 50% of predicted value and forced expiratory volume (FEV) less than 2 liters in 1 second indicate a high risk for pulmonary morbidity.

Special attention should be paid to patients with chronic obstructive pulmonary disease. A preoperative management protocol used before surgery will unequivocally reduce the incidence of postoperative complications. Features of this protocol include the following10:

  1. Administration of a bronchodilator
  2. Administration of an expectorant
  3. Administration of adequate fluid volumes
  4. Use of incentive spirometry
  5. Use of postural drainage
  6. Administration of antibiotics for purulent sputum

If less severe pulmonary problems are present, cessation of smoking, use of incentive spirometry, chest physiotherapy, and administration of a bronchodilator will enhance pulmonary function before surgery.

One of the less severe respiratory diseases encountered is bronchial asthma. Approximately 25 million Americans are afflicted with this disease.11 Patients may be asymptomatic or may present with dyspnea, chest tightness, or chronic cough without wheezing. On other occasions, they present with classic symptoms of dyspnea and wheezing. Whenever an asthmatic component of any pulmonary disease is suspected, blood gas determinations and pulmonary function studies are indicated. FEV is one of the most useful of the pulmonary studies. Bronchodilators are used to assist in determining whether pulmonary pathology is reversible or whether more serious chronic pulmonary problems exist. If the FEV is less than 75% of predicted value, the patient can undergo surgery with general anesthesia. In addition, if the patient was asymptomatic and if the PaO2 and PaCO2 values are normal or minimally decreased, no surgical risks should accrue from anesthesia. Patients might require treatment with theophylline. The presence of moderate or severe symptoms, changes in FEV more than 75% of predicted value, and depression of PaO2 or elevation of PaCO2 mandate intensive evaluation and treatment before elective surgery.

Preoperative care of patients with bronchial asthma involves the following:

  1. Removal of bronchial irritants (e.g., smoking)
  2. Attention to hydration (patients must be well hydrated to allow clearance of secretions)
  3. Attention to premedication (codeine, morphine, and cholinergic agorests can exacerbate asthma)

The primary surgical risk is the development of bronchitis. In addition, at the time of endotracheal intubation, quiescent asthma can flare up, probably because of irritation of airway receptors. Halothane is among the best anesthetic agents available for use in asthmatic patients. It is effective because it is not irritating to the bronchi.

CONSIDERATIONS INVOLVING THE HEMATOPOIETIC SYSTEM

A routine complete blood count is essential in the evaluation of preoperative patients. A careful detailed history should seek out abnormalities in the clotting cascade. Symptoms such as easy bruising and episodes of prolonged bleeding mandate determination of a prothrombin time, a platelet count, a bleeding time, and an activated partial thromboplastin time. Additional clotting factor studies may be needed. Approximately 95% of bleeding abnormalities will be discovered by some combination of the four tests mentioned.

It is widely accepted that a hemoglobin of approximately 10 g/dl is required before anesthesia will be administered for elective surgical procedures. This dictum does not apply to patients with disease conditions such as chronic renal disease or sickle cell anemia. If a surgical candidate presents with a hemoglobin less than 10 g, it is advisable, if feasible, to postpone surgery and treat the patient with iron and vitamin C. In addition, if heavy menstrual flow is contributing to the anemia, suppression of menses would be appropriate. If blood transfusion is needed, packed red blood cells are preferable to whole blood to prevent volume overload. One unit of red blood cells should elevate the hematocrit by three points. Washing of the red blood cells reduces the incidence of reactions. Transfusing patients preoperatively is controversial and is probably only undertaken in emergency situations because of the risk of infection with human immunodeficiency virus (HIV) and hepatitis. Accordingly, consideration of autologous transfusion constitutes an integral part of preoperative planning.

Drug ingestion can create bleeding problems. Aspirin can inactivate platelet function for as long as 10 days after ingestion. The nonsteroidal antiinflammatory agents, steroids, and phenothiazines also interfere with platelet function. Similarly, carbenicillin and ticarcillin retard platelet function. Malnutrition or bowel sterilization can result in a vitamin K deficiency that causes a deficiency in clotting factors. As a result, the prothrombin time is prolonged and increased bleeding will ensue.

Von Willebrand's disease, an abnormality of platelet adhesion and Factor VIII, might not cause preoperative prolongation of the partial thromboplastin time and the bleeding time until surgery is in progress. Therapy with Factor VIII (fresh frozen plasma or cryoprecipitate) will control the bleeding.

Patients with an excess of hemoglobin (e.g., polycythemia vera) are rarely encountered in routine gynecologic practice. Such patients are at increased risk for hemorrhage and thromboses. It is wise to defer elective surgery so that the hematocrit can be reduced below 52%12 and the platelet count to less than 500,000/mm3. Chronic smokers have an elevated hemoglobin value, but levels are far below those in polycythemic patients.

Finally, elective surgery is usually postponed if the platelet count is below 50,000/mm3, especially if the thrombocytopenia has a correctable cause. Spontaneous bleeding can occur if the platelet count is in the 10,000/mm3 range. Platelet transfusion may be given to these patients before and during surgery. The transfused platelets survive for about 4 days in the absence of immune-mediated thrombocytopenia. On other occasions, the platelet count might be normal but platelet function could be impaired by disease conditions such as uremia or dysproteinemias.

ENDOCRINE CONSIDERATIONS

Patients with diabetes mellitus and patients who are taking oral steroids are encountered with some regularity in gynecologic practice. Diabetic patients are at increased risk for cardiovascular problems and wound disruption. In addition, the risk of postoperative infections. usually with gram-negative organisms, is increased. An attempt to reduce these complications will probably require tighter control of blood glucose levels.

The stress of surgery leads to hyperglycemia and insulin resistance, both probably as a result of catecholamine outpouring. Thus, diabetic patients given glucose during surgery develop significant elevation of plasma glucose. Halothane and ether also cause hyperglycemia. Accurate blood glucose measurements can be quickly obtained during surgery using blood glucose measuring meters. Elective surgery should be postponed if the blood glucose level is above 200 mg/dl to allow for better control of diabetes.

Preoperatively diabetic patients should be evaluated for electrolyte imbalance and acid-base deficits along with the other customary studies. One method of managing insulin-dependent diabetic patients preoperatively is as follows:

  1. Administer one third to one half of the usual dose of intermediate-acting insulin on the morning of surgery.
  2. Administer dextrose during surgery.

Two other approaches are increasing in popularity. The no-insulin, no-glucose regimen is one alternative; another alternative involves the use of intravenous insulin during surgery.

A number of patients may be using steroids for inflammatory or other conditions. Steroid ingestion will retard wound healing and depress the host response to infection. In addition, a prednisone dose of 7.5 mg/day for at least 5 days can cause adrenal suppression. This finding is of importance during surgery.

One method of steroid replacement therapy before surgery is hydrocortisone succinate, 100 mg IV, on the evening before surgery, the same dose at the time of surgery, then every 8 hours. If the postoperative course is complicated, steroids should be continued. If the surgical procedure is brief, steroids can be abruptly discontinued without any sequelae.

Finally, the endocrine effects of a rare tumor, pheochromocytoma, should be considered. The diagnosis of this condition mandates the postponement of elective surgery to avoid intraoperative catastrophes of the heart and vascular tree.

CONSIDERATIONS INVOLVING THE GASTROINTESTINAL AND URINARY SYSTEMS

Gastrointestinal Tract

The gastrointestinal tract is important in the preoperative preparation in respect to patients' nutritional status and evaluation of symptoms referable to bowel function. Gastrointestinal symptoms require assessment for possible bowel involvement, either by direct extension of the pelvic disease or by extension of a generalized process (e.g., inflammation). If the bowel process exhibits some chronicity, radiographic studies are indicated. In addition, the existence of chronic bowel symptoms necessitates a careful evaluation of a patient's nutritional profile. Finally, the occurrence of nausea, vomiting, and diarrhea requires that electrolyte values be known. If a patient is “dry” (i.e., has a depleted vascular volume), preoperative fluid administration is increased. Attention to the latter is important before elective surgery because dehydration can lead to hypotension and tachycardia at the time of induction of anesthesia.

In addition to encumbrance of bowel motility, abdominal distention or intestinal obstruction needs to be addressed. Preoperative bowel decompression by way of a long tube may be necessary. In the absence of bowel involvement, emptying of the colon is an established preoperative routine. Emptying of the colon enhances surgical exposure, reduces the chances of bowel injury and contamination, and hastens bowel recovery in the postoperative period.

Urinary Tract

Routine gynecologic patients not undergoing surgery for a urinary tract problem present with few symptoms referable to the bladder and kidneys. If symptoms are present, they are due to pressure on the organ system or obstruction of function. A basic routine urinalysis is indicated in symptomatic patients. The other basic test is an intravenous pyelogram (IVP), which provides information about the anatomy of the urinary tract, the presence of anatomic distortion, the presence of anomalies of the tract, and the possibility of chronic urinary tract diseases. A baseline IVP is rarely necessary for routine gynecologic procedures. However, an IVP is useful in conditions such as ovarian remnant disease, intraligamentous myomas, and severe endometriosis.

Despite increases in renal blood flow due to anesthetic agents such as halothane, patients receiving general anesthesia experience a decrease in renal blood flow and a reduction in glomerular filtration. The end process is a reduction in urinary flow.

Age, underlying renal disease, nephrotoxic medications, and the presence of peritonitis and extrarenal disease are among the conditions that will influence both the preoperative and postoperative renal status of a patient.

Gentamicin is an antibiotic commonly used in the care of gynecologic patients. Its nephrotoxicity is well known; the drug usually has to be administered for at least 2 to 3 days before toxicity becomes manifest. Although oliguria does not occur in the early phases of toxicity, blood urea nitrogen and creatinine levels are elevated. Thus, attention to drug toxicity is important in the preoperative phase, and appropriate renal studies could be obtained.

Patients who are of advanced age, patients who are diabetic, patients with underlying renal deficiency, and patients who are dehydrated are at risk for renal insufficiency from diagnostic dye studies such as IVP.13 The creatinine level above which dye-induced renal malfunction occurs is 2 mg/dl or greater. Only 1 of 20 diabetic patients with a 2.0 mg/dl serum creatinine experienced renal complications after IVP.14

In the preoperative evaluation of renal obstruction, look for simple causes that are easily correctable while keeping in mind the possibility of intrinsic renal disease. Bladder obstruction or drug-induced atony with resulting oliguria and a full bladder can be easily diagnosed by catheterization. A uterus that is enlarged enough to reach the pelvic brim can cause ureteral obstruction in up to 30% of patients. If obstruction is suspected to be higher up, a noninvasive technique such as renal ultrasonography can be used.

A BRIEF LOOK AT ELECTROLYTE PROBLEMS

Vomiting, diarrhea, the use of diuretics, and the presence of an osmotic diuresis due to diabetes mellitus are among the contributing factors that result in electrolyte abnormalities in gynecologic patients. The accompanying sodium depletion results Jn contraction of the intravascular volume. Hemorrhage, sepsis, starvation, fluid restriction, and multiple enemas also contribute to intravascular volume reduction.

Patients with severe vomiting become sodium and potassium depleted due to the loss of these ions in the vomitus and also because they develop hypochloremic metabolic alkalosis, which is associated with renal sodium and potassium loss.15 Similarly, patients with severe diarrhea generally lose sodium and potassium and present with hyperchloremic acidosis.

It is critical that electrolyte and especially potassium abnormalities be corrected before surgery. Hypokalemia can potentiate the effects of neuromuscular blocking agents like pancuronium bromide (Pavulon), create cardiac arrhythmias, and lead to acid-base imbalance.

The adequacy of replacement of intravascular volume is difficult to assess and depends on the contributing causes of volume depletion. For fluid replacement only, isotonic saline and lactated Ringer's solution are commonly used. One liter of infused isotonic saline adds 250 ml to the intravascular compartment.

Monitoring of blood urea nitrogen, urine specific gravity, hematocrit, blood pressure, pulse, and urine output will assist in judging adequate fluid replacement. In addition, osmolality measurements can be used as a guide.

NUTRITIONAL STATUS OF THE PATIENT

Overt malnutrition is rarely encountered in everyday gynecologic practice. Occasionally, some young gynecologic patients who overemphasize strict diet can present with overt malnutrition. Similarly, patients with chronic conditions that interfere with adequate digestion and compromise gastrointestinal function can become undernourished. Body weight is not a very sensitive indicator of the nutritional status of a patient. Adequate nutritional supplementation for 5 to 7 days can correct nutritional imbalance and reduce surgical morbidity.

The proposed surgical procedure will necessitate about a 24% increase in energy requirement above the resting state. In addition, correct nutritional balance accelerates the response to stress, fosters wound healing, and enhances cell-mediated immunologic response. Although routine patients appear to be in proper nutritional balance, simple testing will reveal that as many as 50% of surgical patients are in a state of protein-calorie malnutrition that needs to be corrected.16

Poor skin turgor, muscle wasting, and inanition are obvious signs of malnutrition. Simple measurements can be used to ascertain nutritional status. A patient's body fat can be measured by the use of the Lange calipers. The nondominant midarm triceps skinfold is measured and compared with published norms. Muscle mass can also be measured by obtaining the nondominant midarm circumference, subtracting the value from the triceps skinfold thickness, and multiplying the result by 0.314. This result can then be compared with the standard norms and is normal if the value exceeds 90% of predicted values.

PSYCHOLOGIC CONSIDERATIONS

For years it has been known that women undergoing operations on the female genital tract are subjected to psychological stresses. Depression seems to be the most common psychiatric finding associated with hysterectomy,17 although depression is accentuated when there is a previous psychiatric referral, absence of pelvic disorder, or the presence of a mental problem. Patients undergoing tubal ligation suffer the same sequelae as hysterectomy patients.

A frank discussion about patients' concerns and offers of reassurance should be included in the comprehensive preoperative care delivered to patients. Such assurance goes a long way toward assuaging patients' apprehension, and it is unusual for more intensive psychotherapy to be required if the psychological problems are not very deep. Another aspect of psychological care involves attention to patients' fears and expectations about the surgical experience. Wilson studied 63 elective surgical female patients, 37% of whom underwent abdominal hysterectomy, to assess the effectiveness of preoperative preparation.18 This preparation included teaching of muscle relaxation techniques and education about the entire surgical process. The patients experienced less pain and a reduced need for medication in the postoperative period. They returned to full activity earlier and experienced a shorter hospital stay. Even the patients who used denial as a coping mechanism were helped. Thus, this aspect of care needs emphasis in the preoperative preparation.

ROLE OF ROUTINE TESTING

The current emphasis on cost-effectiveness has resulted in an ongoing evaluation of the need for and yield of routine tests ordered preoperatively. A detailed history and physical examination will in large measure determine the need for tests beyond the routine baseline hemoglobin, hematocrit, and white blood cell count. Only blood urea nitrogen determination seems indicated in the absence of a history of urinary tract problems. The usefulness of routine urinalysis has not been substantiated. In large series of patients studied,19, 20 it seems that chest radiographs are of no value in patients who are younger than 30 years and are undergoing elective surgical procedures if a careful history and physical examination reveal no suspicion of cardiac or pulmonary disease.

Blood glucose determination is indicated in the older population because of the prevalence of diabetes mellitus. Assessments of prothrombin time, platelet count, and partial thromboplastin time are not indicated unless a careful history and physical examination and disease diagnosis warrant a suspicion of a bleeding disorder.

IVP is one of the standard studies used when extensive pelvic surgery is indicated. There is no need to order an IVP before routine gynecologic surgery. Noninvasive studies should be used instead of IVP in diabetic patients. Barium enemas should be ordered if patients have symptoms referable to the gastrointestinal tract. Electrocardiograms can be deferred in patients under 35 years of age with a benign cardiac history and physical examination.21 When an electrocardiogram is deferred, careful review of exercise tolerance is an integral segment of the history taking.

In summary, patient age, disease diagnosis, and prevalence of associated other disease coupled with a careful and detailed history and physical examination will determine the need for specific preoperative testing.

INCREASING ROLE OF AN OUTPATIENT SETTING

In an effort to reduce health care costs, more of the preoperative evaluation is being performed in an outpatient setting instead of in the hospital on the day before surgery. This shift in delivery of care has generated an ongoing evaluation so that the quality of the preoperative care will not be sacrificed. Physician and nursing time have to be allotted during conventional working hours to begin this evaluation. Some of the in-depth evaluation (e.g., the tedious but useful screening details obtained by a medical student) has therefore been eliminated. Fortunately, by selecting apparently healthy patients for this exercise, any minor misjudgment has not resulted in serious sequelae.

The preoperative studies have to be streamlined, and patients are required to make a second visit either to the hospital or to an equivalent setting to obtain the tests. Physicians and their support staff must review these tests to assure results. If necessary, revisit might be scheduled to institute corrective action, obtain additional information, seek consultation with other specialists, or delay the planned procedure. Finally, in an outpatient setting, a physician and staff must counsel the patient about her obligations on the night before surgery because many patients are now admitted on the same-day surgery concept.

Accordingly, both physicians and patients spend more time in the outpatient setting. Some costs (e.g., the preoperative hospital stay) are curtailed, whereas other costs (e.g., increased use of support staff) are increased. This preoperative outpatient care setting has an impact on hospital services, nursing services, and physician personnel distribution, to mention a few. Finally, the preoperative planning has to address the potential for an early discharge and offer patients recommendations and information about recovery at alternative facilities.

SUMMARY

Preoperative management is an evolving, dynamic process in which patients and physicians are interdependent, a process that is constantly aimed at enhancing outcome from a surgical procedure. It must be thorough, streamlined, educational, and cost-effective. Physician and patient satisfaction is the final goal.

REFERENCES

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2

Goldman L, Caldera DL, Nussbaum SR et al: Multifactorial index of cardiac risk in noncardiac surgical procedures. N Engl J Med 297: 845, 1977

 

3

Driscoll AC, Hobika JH, Etsten BE et al: Clinically unrecognized myocardial infarction following surgery. N Engl J Med 264: 633, 1961

 

4

Tarhan S, Moffitt EA, Taylor WF et al: Myocardial infarction after general anesthesia. JAMA 220: 1451, 1972

 

5

Steen PA, Tenker JH, Tarhan S: Myocardial reinfarction after anesthesia and surgery. JAMA 239: 2566, 1978

 

6

Goldman L, Caldera DL, Southwick FS et al: Cardiac risk factors and complications in non-cardiac surgery. Medicine 57: 357, 1978

 

7

Goldman L, Caldera DL: Risks of general anesthesia and elective operation in the hypertensive patient. Anesthesiology 50: 285, 1979

 

8

Ferguson RK: Cost and yield of hypertensive evaluation: Experience of a community-based referral clinic. Ann Intern Med 82: 761, 1975

 

9

Tisi GM: Preoperative evaluation of pulmonary function. Am Rev Respir Dis 119: 293, 1979

 

10

Gracey DR, Divertie MB, Didier EP: Preoperative pulmonary preparation of patients with COPD. Chest 76: 123, 1979

 

11

White WH: Social and economic aspects. NIAID Task Force Report: Asthma and Other Allergic Disease, NIH Publication No. 79: 387, 1979

 

12

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