6.3 Ancillary Personnel

The facility or office must be staffed by individuals with the training and experience required to assist in the care of the patient [9, 10]. Use of qualified and experienced operating room personnel has been shown to improve operating room efficiency and reduce surgical morbidity [11, 12]. All personnel assisting in the operating room and recovery area should maintain Basic Life Support (BLS) Certification [13]. At least one health care provider in the facility must be certified to deliver advanced cardiac life support (ACLS) when anesthesia is administered [14]. The surgeon may prefer to enlist the assistance of an anesthesiologist or CRNA to provide intraoperative anesthesia and monitoring. If the surgeon elects to administer parenteral sedative or analgesic medication without the assistance of an anesthesiologist or CNRA, then a second licensed health care provider should be available to deliver the medications to the patient and monitor the patient throughout the perioperative period [15]. The use of untrained, unlicensed personnel to administer medication to the patient and monitor the patient is associated with an increased risk of anesthesia-related complications to the patient. The nurse who has been assigned to monitor the patient during the administration of sedative and analgesic medication should not be required to double as a circulating or scrub nurse [16]. Preferably, the surgeon who chooses to administer anesthesia should also be ACLS Certified.

6.4 Preoperative Evaluation

Despite the development of minimally invasive nonsurgical and surgical procedures, the importance of the preoperative anesthesia evaluation should not be minimized. An old adage within many anesthesia training programs is that while there may be minor surgical procedures, there is no such thing as a minor anesthetic. If the surgeon chooses to administer the anesthesia then he/she assumes the full responsibility of the preoperative assessment. Even if an anesthesiologist or CRNA is to be involved on the day of surgery, a carefully performed preoperative evaluation by the surgeon is instrumental in reducing potential delays or cancellations of surgery and improving the overall perioperative risk to the patient [17].

Acomprehensive preoperative patient questionnaire is an invaluable tool to begin the initial assessment. Information contained in the history may determine the diagnosis of the medical condition in nearly 90% of patients [18]. Information requested by the questionnaire should include all current and prior medical conditions, prior surgeries and types of anesthesia received, adverse outcomes to previous anesthetics or other medications, eating disorders, prior or current use of antiobesity medications, current use of homeopathic or herbal supplements, and prior family history of severe reactions to anesthetics such as malignant hyperthermia. A complete review of systems, including questions about the presence of chest pain, shortness of breath, loss of consciousness, spontaneous bleeding or bruising, spontaneous weight loss, fever, or fatigue is crucial in identifying previously undiagnosed, untreated medical conditions, which could impact the outcome of anesthesia and surgery. Obtaining a family history of sudden, unsuspected illness or death is also important in identifying patients with potentially undiagnosed medical conditions.

Aroutine physical examination may alert the surgeon to certain medical conditions such as undiagnosed or inadequately treated hypertension, cardiac arrhythmias, cardiac failure, or bronchial asthma, which could result in increased risk to the patient during the perioperative period. Preliminary assessment of the head and neck anatomy may be useful to predict possible challenges in the event of an endotracheal intubation even if general anesthesia is not planned. Preoperative history and physical examination has been shown to be superior to laboratory analysis in determining the clinical course of anesthesia and surgery [19–23].

For patients with complicated, unstable, or previously unrecognized medical conditions, a consultation by the appropriate medical specialist is indicated to determine if the patient’s medical conditional is optimally managed, if the medical condition may cause a significant increased in the perioperative risk to the patient, and to assist with the perioperative medical management of the patient if required. Additional preoperative testing may be considered medically necessary by the consultant.

Guidelines for the judicious use of preoperative laboratory screening tests for healthy patients not taking medications are presented in Table 6.1. Additional

preoperative tests, noted in Table 6.2, may be indicated for patients with prior medical conditions or risk factors for anesthesia and surgery.

Excessive or indiscriminately ordered preoperative laboratory testing for healthy patients not taking

Table 6.1 Guidelines for preoperative testing in healthy patients (ASA 1-11)

aPregnancy test for potentially childbearing females suggested Source: Adapted from Roizen et al. [24]

Table 6.2 Common indications for additional risk-specific testing

Electrocardiogram

History: Coronary artery disease, congestive heart failure, prior myocardial infarction, hypertension, hyperthyroidism, hypothyroidism, obesity, compulsive eating disorders, deep venous thrombosis, pulmonary embolism, smoking, chemotherapeutic agents, chemical dependency, chronic liver disease.

Symptoms: Chest pain, shortness of breath, dizziness

Signs: Abnormal heart rate or rhythm, hypertension, cyanosis, peripheral edema, wheezing, rales, rhonchi

Chest X-ray

History: Bronchial asthma, congestive heart failure, chronic obstructive pulmonary disease, and pulmonary embolism

Symptoms: Chest pain, shortness of breath, wheezing, unexplained weight loss, and hemoptysis

Signs: Cyanosis, wheezes, rales, rhonchi, decreased breath sounds, peripheral edema, abnormal heart rate or rhythm

Electrolytes, glucose, liver function tests, BUN, creatinine

History: Diabetes mellitus, chronic renal failure, chronic liver disease, adrenal insufficiency, hypothyroidism, hyperthyroidism, diuretic use, compulsive eating disorders, diarrhea

Symptoms: Dizziness, generalized fatigue or weakness

Signs: Abnormal heart rate or rhythm, peripheral edema, jaundice

Urinalysis

History: Diabetes mellitus, chronic renal disease, and recent urinary tract infection

Symptoms: Dysuria, urgency, frequency, and bloody urine

Source: Adapted from Roizen et al. [25]

medications has limited value in predicting surgical or anesthesia-related morbidity and mortality [26–30].

6.4.1 Preoperative Risk Assessment

One critical goal of the preoperative evaluation is the determination of a patient’s overall level of risk related to the administration of anesthesia. By first establishing a patient’s level of risk, strategies to reduce the patient’s exposure may be considered. Compelling evidence suggests that certain coexisting medical conditions significantly increase the risk for perioperative morbidity and mortality [15, 31]. The risk classification system developed by the ASA in 1984 (Table 6.3) [32] has become the most widely accepted method of preoperative risk assessment. The value of the ASA system in predicting which patients are at higher risk for morbidity [33] and mortality [34–36] has been confirmed by numerous studies. Goldman and Caldera [37] established a risk assessment index based on cardiac disease, which has also been demonstrated to be effective in predicting perioperative mortality [38, 39]. Physicians should incorporate one of the acceptable risk classification systems as an integral part of the preoperative evaluation.

The type of surgery plays a key role in the overall risk of morbidity and mortality to the patient. The consensus of multiple studies confirms that more invasive surgeries, surgeries with multiple combined procedures, surgeries of prolonged duration, and surgeries with significant blood loss increases the risk of

Table 6.3 The American Society of Anesthesiologists’ physical status classification

of obesity. Patients with a BMI over 30 are considered obese, while a BMI over 35 indicates morbid obesity [60]. Morbidly obese patients (BMI greater than 35) undergoing major surgery or any surgery where a general anesthetic is planned, should preferentially be referred to a hospital with health-care providers experienced with the management of this high-risk group.

Airway control in morbidly obese patients may be particularly challenging due to anatomical abnormalities of the airway [61]. The combination of higher gastric volume, lower gastric pH, and increased frequency of esophageal reflux elevates the risk of dreaded pulmonary aspiration [62]. The morbidly obese patient may have severe restriction in pulmonary function [63], which is further compromised in the supine position [64]. Pulmonary function may dangerously deteriorate when heavy sedation or general anesthesia is administered to the morbidly obese patient [65]. Hypoxemia may develop precipitously in this patient population while receiving heavy sedation or general anesthesia anytime in the perioperative period. Respiratory impairment may persist for up to 4 days after surgery or anesthesia [66].

Premedication with metaclopramide, or other dopamine receptor antagonist, and ranitidine, or similar histamine type-2 receptor antagonist, should be administered the evening prior to and on the morning of surgery to reduce the risk of pulmonary aspiration pneumonitis [67]. Because of the increased risk of deep venous thrombosis (DVT) [68] and pulmonary embolism (PE) [69], prophylactic measures such as lower extremity pneumatic compression devices and early ambulation should be used.

Fatal cardiac arrhythmias, sudden congestive heart failure, and intractable hypotension has developed in patients receiving anesthesia who have previously taken appetite suppressant medications such as aminorex fumarate, dexfenfluramine (Redux), fenfluramine (Pondimin), and phentermine (Ionam, Adipex-P, Fastin, Oby-Cap, Obenix, Oby-trim, or Zantryl). Some authors advocate a cardiac evaluation with an echocardiogram to rule out valvular disease associated with these medications, and continuous wave Doppler imaging with color-flow examination for any patient who has previously taken any antiobesity medications. Sustained hypotension may not respond to ephedrine, a popular vasopressor. Phenylephrine is the treatment of choice for hypotension in this patient population [70].

6.4.5 Hypertension

Perioperative mortality is significantly increased in patients with untreated or poorly controlled hypertension [71, 72]. Satisfactory control of hypertension reduces the risk of mortality due to complications related to cardiovascular and cerebral vascular disease [73–75]. Most authors concur that preoperative stabilization of hypertension reduces perioperative cardiovascular complications such as ischemia [76–78]. Patients with undiagnosed or poorly controlled hypertension can easily be identified in the preoperative examination and referred to the family physician or internist for evaluation and treatment. Attributing severe hypertension to the patient’s preoperative level of anxiety can be a deadly assumption. Considering that many effective medications are available for the treatment of hypertension, there is little defense for the physician who proceeds with surgery in a patient with uncontrolled hypertension.

Previously prescribed antihypertensive medications should be continued up to and including the morning of surgery. Abrupt withdrawal from these medications may result in dangerous rebound hypertension [79]. The only exception are the class of medications known as angiotensin-converting enzyme (ACE) inhibitors, which have been associated with hypotension during the induction of general anesthesia [80].

While mild to moderate perioperative hypertension may be a response to anxiety, an inadequate level of anesthesia, or poor pain control, these cases of hypertension are usually accompanied by other signs such as verbal complaints of pain during local anesthesia, patient movement during general anesthesia, tachycardia, or tachypnea. If the pain treatment, anxiolytics, and depth of anesthesia have been deemed appropriate, then initiating treatment of the blood pressure is indicated.

Beta-adrenergic receptor blocking agents, such as propranolol, judiciously administered intravenously in doses of 0.5 mg at 10-min intervals, is especially effective in treating perioperative hypertension, which is accompanied by tachycardia. Even small doses of beta-adrenergic blocking agents can reduce the incidence of cardiac ischemia [78]. Labetalol, an antihypertensive medication with combined alpha-adrenergic and beta-adrenergic receptor blocking properties, administered in 10 mg doses every 10 min, is also a safe and effective alternative for treating both hypertension and tachycardia [81].