For severe hypertension, hydralazine, a potent vasodilator may be useful in 2.5–5 mg doses intravenously at 15-min intervals. The effects of hydralazine may be delayed up to 20 min and sustained for hours. Hydralazine may cause tachycardia or hypotension, especially if the patient is hypovolemic [82].

6.4.6 Diabetes Mellitus

Patients with diabetes mellitus have a significantly increased rate of surgical morbidity and mortality compared to nondiabetic patients [83]. These complications are primarily related to the consequences of the end-organ disease such as cardiovascular disease, renal disease, and altered wound healing which is associated with diabetes mellitus [31, 84, 85]. The preoperative evaluation should identify diabetic patients with poor control as well as medical conditions associated with diabetes such as cardiovascular disease and renal insufficiency. The physician should keep in mind that diabetic patients have a greater incidence of silent myocardial ischemia [86].

The minimum preoperative analysis for the diabetic patient should include fasting blood sugar, glycosylated hemoglobin, electrolytes, BUN, creatinine, and EKG. If there are any concerns regarding the patient’s medical stability, the patients should be referred to a diabetologist, cardiologist, nephrologist, or other indicated specialist. Patients with brittle diabetes or other severe medical conditions should preferentially undergo surgery in a hospital-based surgical unit.

The primary objective of the perioperative management of the stable diabetic patient is to avoid hypoglycemia. Although patients are usually NPO after midnight prior to surgery, a glass of clear juice may be taken up to 2 h prior to surgery to avoid hypoglycemia. To minimize the risk of perioperative hypoglycemia, patients should not take their usual dose of insulin or oral agents on the morning of surgery. Surgery of the diabetic patient should be scheduled as early as possible in the morning to further reduce the risk of perioperative hypoglycemia. After the patient arrives, a preoperative fasting glucose should be determined. An intravenous infusion of fluid containing 5% dextrose should be initiated and continued at 1–2 ml/kg/h until oral fluids are

tolerated in the recovery room. Usually, one-half of the patient’s scheduled dose of insulin is administered after the intravenous dextrose fluid infusion has begun [87].

At least one intraoperative glucose should be measured for surgeries greater than 2 h, especially if general anesthesia is used. A final glucose level should be checked just prior to discharge. Glucose levels above 200 may be effectively managed with a sliding scale of insulin [88].

Treatment regimen directed toward tighter control of the blood glucose, such as insulin infusions, do not necessarily improve perioperative outcome, and recent data indicates that the risk of hypoglycemia may be greater with these regimen [89, 90]. It is imperative that diabetic patients tolerate oral fluids without nausea or vomiting prior to discharge.

6.4.7 Pulmonary Disease

An estimated 4.5% of the population may suffer some form of reactive airway disease which may influence perioperative pulmonary function [91]. These medical conditions include a recent upper airway infection, bronchial asthma, chronic bronchitis, chronic obstructive airway disease, and a history of smoking. A thorough evaluation of the patient’s pulmonary function is indicated if any of these medical conditions are identified in the preoperative history. A careful history should help to separate these patients into lowand high-risk groups. The degree of preoperative respiratory dyspnea correlates closely with postoperative mortality [92]. Using a simple grading scale, the patients preoperative pulmonary function can be estimated (Table 6.4). Patients with level 2 dyspnea or greater should be referred to a pulmonologist for more

Table 6.4 Grade of dyspnea while walking

Level Clinical response

0No dyspnea

1Dyspnea with fast walking only

2Dyspnea with one or two blocks walking

3Dyspnea with mild exertion (walking around the house)

4Dyspnea at rest

Source: Adapted from Boushy et al. [92]

complete evaluation and possibly further medical stabilization. Patients with level 3 and 4 dyspnea are not suitable patients for outpatient surgery. The benefits of elective surgery in these patients should be carefully weighed against the increased risk.

Since upper airway infection may affect pulmonary function for up to 5 weeks [93], major surgery requiring general endotracheal anesthesia should be postponed, especially if the patient suffers residual symptoms such as fevers, chills, coughing, and sputum production, until the patient is completely asymptomatic.

Multiple studies have confirmed that patients who smoke more than one pack of cigarettes daily have a higher risk of perioperative respiratory complications compared to nonsmokers. However, cessation of smoking immediately prior to surgery may not improve the patient’s outcome.

In fact, the risk of perioperative complications may actually increase if smoking is abruptly discontinued immediately prior to surgery. Cessation of smoking for a full 8 weeks may be required to successfully reduce the risk of perioperative pulmonary complications [94]. If the preoperative physical examination reveals respiratory wheezing, reversible bronchospasm should be optimally treated prior to surgery, even if this treatment requires that the surgery be delayed. Therapeutic agents include inhaled or systemic selective beta-adrenergic receptor type-2 agonist (albuterol) as a sole agent or in combination with anticholinergic (ipratropium) and locally active corticosteroid (beclomethasone diproponate) medications [95]. Continuing the patient’s usual asthmatic medications up to the time of surgery [96], combined with postoperative use of incentive spirometry [97], effectively reduces postoperative pulmonary complications.

With regard to medically stabilized pulmonary disease, there are no conclusive, prospective, randomized studies to indicate which anesthesia technique or medication results in improved patient outcome.

6.4.8 Obstructive Sleep Apnea

The National Commission on Sleep Disorders Research estimates that 18 million Americans suffer with obstructive sleep apnea (OSA). Unfortunately, the majority of patients with sleep apnea remain

undiagnosed [98]. The incidence of OSA increases among obese patients [99]. Since the target population for many cosmetic surgical procedures includes patients with morbid obesity, concern about the diagnosis and safe treatment of patients with OSA becomes even more relevant.

OSA is a result of a combination of excessive pharyngeal adipose tissue and inadequate pharyngeal soft tissue support [100]. During episodes of sleep apnea, patients may suffer significant and sustained hypoxemia. As a result of the pathophysiology of OSA, patients develop left and right ventricular hypertrophy [101]. Consequently, patients have a higher risk of ventricular dysarrhythmias and myocardial infarction [102].

Most medications used during anesthesia, including sedatives such as diazepam and midazolam; hypnotics such as propofol; and analgesics such as fentanyl, meperidine, and morphine, increase the risk for airway obstruction and respiratory depression in patients with OSA [103]. Death may occur suddenly and silently in patients with inadequate monitoring [104]. A combination of anatomical abnormalities makes airway management, including mask ventilation and endotracheal intubation, especially challenging in obese patients with OSA [105]. Perioperative monitoring, including visual observation, must be especially vigilant to avoid perioperative respiratory arrest in patients with OSA.

For patients with severe OSA, particularly those with additional coexisting medical conditions such as cardiac or pulmonary disease, surgery requiring sedation, analgesic, or general anesthesia, performed on an outpatient basis is not appropriate. For these highrisk patients, monitoring should continue in the intensive care unit until the patient no longer requires parenteral analgesics. If technically feasible, local or regional anesthesia may be preferable in patients with severe OSA. Postoperatively, patients with any history of OSA should not be discharged if they appear lethargic or somulent or there is evidence of even mild hypoxemia [106].

During the preoperative evaluation of the obese patient, a presumptive diagnosis of OSA may be made if the patient has a history of loud snoring, long pauses of breathing during sleep, as reported by the spouse, or daytime somnolence [107]. If OSA is suspected, patients should be referred for a sleep study to evaluate the severity of the condition.