What are the essential steps for preoperative clearance in an adult patient with a history of hypertension, diabetes, or cardiovascular disease undergoing surgery?

Preoperative Clearance for Adults with Hypertension, Diabetes, or Cardiovascular Disease

For adults with hypertension, diabetes, or cardiovascular disease undergoing noncardiac surgery, proceed with surgery if blood pressure is <180/110 mmHg, continue most antihypertensive medications (except consider holding ACE inhibitors/ARBs 24 hours before), target perioperative glucose 100-180 mg/dL, and perform risk stratification using clinical predictors and functional capacity rather than routine testing. 1

Blood Pressure Management Algorithm

Preoperative Assessment

• Defer elective surgery if systolic BP ≥180 mmHg or diastolic BP ≥110 mmHg in patients with cardiovascular risk factors, as this threshold increases perioperative cardiovascular complications, stroke, and bleeding risk 1, 2
• For BP <180/110 mmHg, proceed with surgery while continuing antihypertensive therapy 1, 3
• Target BP <130/80 mmHg before major elective procedures when feasible, but do not delay surgery solely to achieve this if BP is below the 180/110 mmHg threshold 1, 2

Medication Management

• Continue beta-blockers perioperatively in patients already taking them to prevent rebound hypertension and sympathetic surge, which increases mortality 1, 2, 4
• Never start beta-blockers on the day of surgery in beta-blocker-naïve patients—this is potentially harmful 1, 4
• Consider discontinuing ACE inhibitors and ARBs 24 hours preoperatively as recent cohort evidence demonstrates lower rates of death, stroke, myocardial injury, and intraoperative hypotension compared to continuing these medications 1, 2, 3
• Continue calcium channel blockers through the day of surgery 2
• Never abruptly discontinue clonidine—continue perioperatively to avoid rebound hypertension 1, 4, 3

Intraoperative Targets

• Maintain mean arterial pressure (MAP) ≥60-65 mmHg or systolic BP ≥90 mmHg to reduce risk of myocardial injury, acute kidney injury, and mortality 1, 2, 4, 3
• Consider higher BP targets in older adults (≥65 years) or those with chronic hypertension to maintain organ perfusion 2, 4

Postoperative Management

• Resume antihypertensive medications as soon as clinically reasonable when the patient can tolerate oral medications to reduce 30-day mortality 1, 4, 3
• First address reversible causes of postoperative hypertension: pain control, volume status, bladder distention, and oxygenation 1, 2, 4
• Use IV antihypertensives (nicardipine, clevidipine, or labetalol) if BP remains >180/110 mmHg after addressing reversible causes 1, 2, 4

Diabetes Management Protocol

Preoperative Optimization

• Target A1C <8% for elective surgeries whenever possible 1
• Perform preoperative cardiac risk assessment in patients with diabetes who are at high risk for ischemic heart disease or those with autonomic neuropathy or renal failure 1

Perioperative Glucose Targets

• Target blood glucose 100-180 mg/dL in the perioperative period within 4 hours of surgery 1
• Tighter targets than 80-180 mg/dL do not improve outcomes and increase hypoglycemia risk 1

Medication Adjustments

• Hold metformin on the day of surgery 1
• Discontinue SGLT2 inhibitors 3-4 days before surgery to prevent euglycemic diabetic ketoacidosis 1
• Hold other oral glucose-lowering agents the morning of surgery 1
• Give half of NPH dose or 75-80% of long-acting analog insulin dose on the day of surgery 1
• Monitor blood glucose at least every 2-4 hours while NPO and dose with short- or rapid-acting insulin as needed 1

Perioperative Insulin Strategy

• Use basal-bolus insulin coverage (basal insulin plus premeal short- or rapid-acting insulin) rather than correction-only insulin, as this improves glycemic outcomes and lowers perioperative complications 1
• For patients on glucocorticoids, administer NPH insulin concomitantly with intermediate-acting steroids, as NPH peaks at 4-6 hours 1
• Reduce evening-before-surgery insulin by 25% to achieve target perioperative glucose with lower hypoglycemia risk 1

Cardiovascular Risk Stratification

Clinical Risk Assessment

• Use validated risk-prediction tools (such as the Revised Cardiac Risk Index) to predict perioperative major adverse cardiovascular events 1
• Assess three key components: clinical risk predictors, functional capacity, and surgery-specific risk 1

Clinical Risk Predictors (Stratified)

Major predictors requiring evaluation regardless of preoperative status: 1

• Unstable coronary syndromes (acute MI, unstable angina)
• Decompensated heart failure
• Significant arrhythmias (high-grade AV block, symptomatic ventricular arrhythmias, supraventricular arrhythmias with uncontrolled rate)
• Severe valvular disease

Intermediate predictors: 1

• History of ischemic heart disease
• History of compensated heart failure
• Diabetes mellitus (especially insulin-dependent)
• Renal insufficiency (creatinine >2.0 mg/dL)
• Cerebrovascular disease

Functional Capacity Assessment

• Patients with functional capacity ≥4 METs can generally proceed to intermediate-risk surgery without further cardiac testing 1
• Poor functional capacity (<4 METs) combined with intermediate clinical predictors warrants consideration of noninvasive testing for higher-risk surgeries 1

Surgery-Specific Risk Categories

High-risk procedures (cardiac risk >5%): 1

• Emergent major operations
• Aortic and major vascular surgery
• Peripheral vascular surgery
• Prolonged procedures with large fluid shifts or blood loss

Intermediate-risk procedures (cardiac risk 1-5%): 1

• Intraperitoneal and intrathoracic surgery
• Carotid endarterectomy
• Head and neck surgery
• Orthopedic surgery
• Prostate surgery

Low-risk procedures (cardiac risk <1%): 1

• Endoscopic procedures
• Superficial procedures
• Cataract surgery
• Breast surgery

Selective Testing Strategy

Electrocardiography

• Obtain ECG for patients undergoing high-risk surgery 1
• Obtain ECG for patients undergoing intermediate-risk surgery who have additional cardiovascular risk factors 1
• ECG not required for low-risk surgery 1

Laboratory Testing

• Electrolytes and creatinine: Test patients with chronic disease (heart failure, renal disease) and those taking medications predisposing to electrolyte abnormalities (diuretics, digoxin) 1
• Random glucose: Test patients at high risk of undiagnosed diabetes; A1C testing only if results would change perioperative management 1
• Complete blood count: Indicated for patients with diseases increasing anemia risk or when significant perioperative blood loss is anticipated 1
• Coagulation studies: Reserved for patients with bleeding history, medical conditions predisposing to bleeding, or those taking anticoagulants 1

Chest Radiography

• Reasonable for patients at risk of postoperative pulmonary complications if results would change perioperative management 1
• Not routinely indicated otherwise 1

Urinalysis

• Recommended for patients undergoing invasive urologic procedures or implantation of foreign material 1
• Not routinely indicated for other surgeries 1

Special Populations

Cardiac Implantable Electronic Devices (CIEDs)

• Patients with pacemakers require evaluation at least annually; those with ICDs require semi-annual evaluation 1
• The cardiology team should formulate a CIED prescription for perioperative management, which may involve interrogation, reprogramming (changing to asynchronous mode, inactivating ICD therapies), or magnet application 1

Pulmonary Hypertension

• Continue chronic pulmonary vascular targeted therapy (phosphodiesterase-5 inhibitors, endothelin receptor antagonists, prostanoids) unless contraindicated 1
• Preoperative evaluation by a pulmonary hypertension specialist is beneficial for patients with features of increased perioperative risk, as mortality rates range from 4-26% and morbidity rates from 6-42% 1

Adult Congenital Heart Disease

• Perform preoperative evaluation in a regional center specializing in congenital cardiology for high-risk patients (prior Fontan procedure, cyanotic disease, pulmonary arterial hypertension, clinical heart failure, significant dysrhythmia) 1

Critical Pitfalls to Avoid

• Do not perform routine preoperative testing in asymptomatic patients undergoing low-risk procedures—this increases costs without changing management 1
• Do not delay surgery for coronary revascularization unless it would be indicated independent of the noncardiac surgery, as prophylactic revascularization does not reduce perioperative risk 1
• Do not abruptly stop beta-blockers or clonidine—this causes rebound hypertension with increased mortality 1, 2, 4, 3
• Do not continue SGLT2 inhibitors into the perioperative period—stop 3-4 days before surgery 1
• Do not use correction-only insulin in surgical patients with diabetes—use basal-bolus coverage 1
• Do not target perioperative glucose <80 mg/dL—this increases hypoglycemia without improving outcomes 1