Hypertension, defined as two or more blood pressure (BP) readings greater than 140/90 mm Hg, affects 25% of adults in the United States. Testing may include ECG, blood urea nitrogen, creatinine, or cardiac/primary care physician evaluation. ECG is usually recommended in patients over age 50 or with cardiac disease.

It is recommended to delay surgery for severe or untreated hypertension (systolic BP > 200 mm Hg, diastolic BP > 120 mm Hg) until BP is less than 180/110 mm Hg. Below a BP of 180/110, there is no evidence to support cancellation of surgery. Antihypertensive medications should be taken regularly, up to and on the day of surgery. Exceptions are diuretics and combination pills with diuretics due to concerns of potential electrolyte imbalance. In addition, some centers recommend withholding ACE inhibitors due to concerns of refractory hypotension postinduction with general anesthesia.

BP should be normalized as much as possible before surgery, especially in patients with severe end-organ disease; it is
important to note that sometimes intraoperative hypotension may be more dangerous than hypertension (6). Perioperative monitoring is required, with appropriate oral or intravenous (IV) medications dispensed as required.

Current cardiac guidelines support postponing elective surgeries after an MI for between 6 weeks and 6 months. Preoperative considerations are similar to those with hypertensive patients; in addition, it is helpful to determine the presence and degree of ischemia and overall myocardial function. The presence of chest discomfort, shortness of breath, and methods of relief should be addressed in the history, and ECG should be obtained in symptomatic patients (7). The Revised Cardiac Risk Index represents the best predictor of cardiac risk in noncardiac surgical patients (8). In patients currently taking beta-blockers and statins, continuation of these medications perioperatively is recommended. Heart rate control is important in this population and should remain at less than 70 beats/min if possible (9,10,11,12 and 13). Intraoperatively, diastolic BP should be maintained to provide adequate coronary artery perfusion. IV sedation and monitored anesthesia care (MAC) represent good alternatives to general anesthesia if appropriate for the procedure.

Currently, no prophylaxis for infectious endocarditis is recommended for patients with aortic stenosis, aortic insufficiency, mitral stenosis, mitral regurgitation, mitral valve prolapse, tricuspid regurgitation, or hypertrophic cardiomyopathy (14).

Electrocautery may cause electromagnetic interference with both pacemakers and AICDs. Use and power output of electrocautery should be kept to a minimum and should be avoided if in close proximity to the device. Magnet application is commonly used with pacemakers although its routine use is discouraged by some. Typically, application of a magnet converts most pacemakers to asynchronous pacing at a fixed rate; occasionally, this can cause hemodynamic instability.

With AICDs, it is best to contact the manufacturer’s representative before the procedure. The representative will give guidance on how to disable the device, either by application of a magnet or by interrogation and disabling by the representative. In either case, the representative should be present postoperatively to interrogate the device for proper functioning.

Asthma patients with mild, well-controlled symptoms are at no greater risk than normal patients. Exercise levels, medical therapy, and exacerbations are important to elicit from patient histories. Recent emergency department visits or use of prednisone are useful indicators of disease severity. Pulse oximetry is helpful to monitor oxygen saturation levels. CXR may be beneficial for patients with signs or symptoms of pneumothorax or infection. Medications (bronchodilators, steroids, antibiotics) should be continued on the day of surgery (15).

COPD requires similar evaluation and management, with examination possibly including sputum culture. IV sedation with local anesthesia is safest for this patient population, although epidural or spinal anesthesia may be acceptable (16).

Initial workup for diabetic patients should include evaluation of end-organ disease (neuropathy, nephropathy, retinopathy), vascular status, orthostatic vital signs, and blood glucose control. Preoperative studies including ECG, CBC, and BMP are usually recommended. Oral hypoglycemics may be held during the initial postoperative period while sliding scale insulin is utilized. Metformin should be held preoperatively for 24 to 48 hours, due to the possibility of lactic acidosis. Historically, insulin-dependent diabetics have been managed by either holding insulin entirely on the day of surgery or by giving one-half to one-third the daily dose of intermediate-acting insulin that morning. More recent trends have associated better long-term outcomes with tighter blood glucose control at the time of surgery. Some centers utilize IV insulin infusions perioperatively. Normal saline (NS) is the IV fluid of choice since the lactate in lactated ringer (LR) solutions may be converted to glucose. Hypoglycemic events may be managed by PO juices or IV doses of Dextrose 50, given in doses of one ampule or less depending
on the severity of the hypoglycemia. Frequent blood glucose checks should be performed during the perioperative period with the recognition that surgical stress and increased catecholamines, as well as infection, can adversely affect blood glucose control and raise glucose levels.

Although obesity is associated with increased morbidity and mortality in the nonsurgical population, there is surprisingly little data to indicate increased risk when undergoing anesthesia for nonbariatric general surgery. Recent studies show that paradoxically, overweight and moderately obese patients have lower mortality rates postoperatively than normal weight patients (17). Nonetheless, patients with obesity and its related comorbidities, including diabetes, hypertension, cardiovascular disease, OSA, and deep vein thrombosis, must be closely monitored and managed. Obesity is associated with an increased risk of difficult intubation.

Patients with OSA have a higher incidence of cardiovascular disease and show increased sensitivity to the respiratory depressant effects of opiates and benzodiazepines. Many of these patients will not have a sleep study or formal diagnosis. Clinical suspicion based on a history of snoring, daytime sleepiness, reported pauses in breathing, and sudden gasping awakening may be useful in determining at-risk patients.

Preoperative laboratory evaluation with a history of anemia typically includes a CBC; if blood loss is not expected and the patient is clinically stable, one might omit the CBC. Patients with sickle cell disorder should not have lower extremity tourniquets applied due to concerns with increased local acidosis, hypoxia, and venous stasis. The need for type and screen or type and cross will depend on the surgical procedure and is generally not recommended for podiatric cases. Patients with a history of vasospastic disorders should avoid epinephrine in local anesthetics.

Specific laboratory testing in this patient population is determined primarily by comorbidities. Elderly patients show increased sensitivity to benzodiazepines whose effects may be significantly prolonged.

The entire surgical and anesthesia process should be thoroughly explained to the parents (and patient if appropriate) to ensure patient trust. Anesthesia or surgical team members should be present from the time parents are separated and accompany the patient to the operating theater. It is often necessary to premedicate pediatric patients in the preoperative holding area to reduce anxiety and improve cooperation. Weight-based dosing should be carefully utilized. In most cases, general anesthesia is better tolerated due to patient maturity level and corresponding emotional stress. IV placement following inhalational induction may be utilized to reduce patient stress and fear of needles.

Malignant hyperthermia (MH) is a rare life-threatening condition that may be precipitated by the volatile halogenated anesthetic agents and the depolarizing neuromuscular blocker, succinylcholine. It is an inherited autosomal dominant disorder whose incidence is reported at 1 in 50,000 patients. MH does not occur with every exposure to triggering agents. Characteristic signs of MH include muscle rigidity, increased oxygen consumption and carbon dioxide production, tachycardia, and increased body temperature. Rhabdomyolysis and electrolyte disturbances may develop. Dantrolene sodium and supportive measures are the mainstay of therapy as well as careful history and avoidance of triggering agents in susceptible patients.