# Management of the Medically Complex Surgical Patient

## Introduction

The OMFS surgeon routinely treats patients with significant medical comorbidities that influence surgical planning, anesthetic management, and perioperative outcomes. A systematic approach to preoperative assessment, risk stratification, and perioperative optimization is essential. This lecture reviews the management of common medical conditions encountered in OMFS practice and their implications for surgical care.

## Preoperative Assessment Framework

### ASA Physical Status Classification

| ASA Class | Description | Examples | Anesthetic Setting |
|-----------|-------------|----------|-------------------|
| I | Healthy, no systemic disease | Healthy nonsmoker | Office appropriate |
| II | Mild systemic disease, no functional limitation | Controlled HTN, mild asthma, BMI 30-40 | Office appropriate |
| III | Severe systemic disease with functional limitation | Poorly controlled DM, COPD, morbid obesity, stable angina | Hospital preferred |
| IV | Severe systemic disease, constant threat to life | Unstable angina, decompensated CHF, ESRD | Hospital required |
| V | Moribund, not expected to survive without surgery | Ruptured aneurysm, massive trauma | Hospital/ICU required |

The ASA classification system stratifies patients by systemic disease severity. ASA I designates a healthy patient with no systemic disease. ASA II indicates mild systemic disease without functional limitation, such as controlled hypertension, mild asthma, or BMI of 30 to 40. ASA III denotes severe systemic disease with functional limitation, including poorly controlled diabetes, COPD, morbid obesity, or stable angina. ASA IV describes severe systemic disease that is a constant threat to life, such as unstable angina, decompensated congestive heart failure, or end-stage renal disease. ASA V is reserved for moribund patients not expected to survive without surgery. The ASA classification guides anesthetic setting selection (office versus hospital) and the intensity of perioperative monitoring.

### Preoperative Workup

The workup begins with a targeted history and physical examination focused on surgical risk factors, along with medication reconciliation to identify drugs requiring perioperative adjustment. Laboratory studies should be ordered based on clinical indication rather than routinely for healthy patients: CBC for anemia, thrombocytopenia, or leukocytosis; BMP or CMP for electrolytes, renal function, and glucose; coagulation studies (PT/INR) for anticoagulated patients; and HbA1c for diabetic patients with a target of less than 8% for elective surgery. An ECG is appropriate for patients with cardiac history, age greater than 65, or active symptoms. Chest radiography is obtained only when clinically indicated, such as for active pulmonary disease or cardiac symptoms.

## Cardiovascular Disease

### Hypertension

Hypertension is the most common comorbidity, with a prevalence of 30 to 40% in adult surgical patients. Antihypertensive medications should be continued on the morning of surgery with a sip of water, with the exception of ACE inhibitors and ARBs, which should be held on the day of surgery due to the risk of intraoperative hypotension. Elective surgery should be deferred if blood pressure exceeds 180/110 mmHg, as uncontrolled hypertension increases perioperative cardiac and cerebrovascular risk. Intraoperative hypertension can be managed with labetalol IV, esmolol IV, or nicardipine infusion.

### Coronary Artery Disease and Heart Failure

The Revised Cardiac Risk Index (RCRI) is used for preoperative cardiac risk stratification, incorporating risk factors including history of ischemic heart disease, congestive heart failure, cerebrovascular disease, diabetes, renal insufficiency, and high-risk surgery. Most OMFS procedures are classified as intermediate-risk with a perioperative cardiac event rate of 1 to 5%. Patients with recent myocardial infarction (less than 60 days), unstable angina, or decompensated heart failure should have elective surgery deferred and cardiology consultation obtained. Beta-blockers must be continued perioperatively, as abrupt withdrawal increases cardiac event risk. Statin therapy should also be continued throughout the perioperative period.

### Valvular Heart Disease

Patients with valvular heart disease should be assessed for infective endocarditis prophylaxis indications. Patients with severe aortic stenosis are at high perioperative risk, and cardiology clearance is essential before proceeding. Prosthetic valve patients require careful anticoagulation management throughout the perioperative period.

![Table showing the Revised Cardiac Risk Index with scoring and perioperative event rates](images/rcri-risk-table.jpg)

## Diabetes Mellitus

### Preoperative Management

HbA1c should be assessed preoperatively with a target of less than 8% for elective surgery; surgery should be considered for postponement if HbA1c exceeds 9%. The fasting glucose target is 140 to 180 mg/dL perioperatively. For type 1 diabetes, insulin should never be withheld completely due to the risk of diabetic ketoacidosis; basal insulin is reduced by 50 to 80% on the morning of surgery. For type 2 diabetes, medication adjustments vary by drug class:

| Medication Class | Perioperative Management | Rationale |
|-----------------|-------------------------|-----------|
| Metformin | Hold day of surgery; hold 48h if contrast or AKI risk | Lactic acidosis risk |
| Sulfonylureas | Hold day of surgery | Hypoglycemia risk while NPO |
| SGLT2 inhibitors | Hold 3-4 days before surgery | Euglycemic diabetic ketoacidosis risk |
| Insulin (basal) | Reduce by 50% morning of surgery | Hypoglycemia risk while NPO |
| DPP-4 inhibitors | May continue | Low hypoglycemia risk |
| GLP-1 agonists | Hold day of surgery | Delayed gastric emptying; aspiration risk |

### Perioperative Considerations

Blood glucose should be monitored every 1 to 2 hours during procedures under general anesthesia. Hyperglycemia greater than 180 mg/dL impairs wound healing and increases surgical site infection risk. Hypoglycemia less than 70 mg/dL is dangerous under anesthesia and is treated with D50 IV. Diabetic patients face increased infection risk, impaired healing, and higher rates of osteomyelitis overall.

## Respiratory Disease

### Asthma

All controller medications including inhaled corticosteroids and long-acting beta-agonists should be continued perioperatively. A rescue inhaler (albuterol) must be available in the operatory. Aspirin and NSAIDs should be avoided in aspirin-sensitive asthma (Samter triad), and elective surgery should be postponed during acute exacerbation.

### COPD

Pulmonary function should be optimized preoperatively, with smoking cessation recommended 4 to 8 weeks before surgery. Bronchodilators should be continued on the morning of surgery. The need for perioperative stress-dose steroids should be assessed in patients on chronic systemic corticosteroids. These patients face increased risk of postoperative respiratory complications, so sedation duration should be minimized.

## Hepatic Disease

The Child-Pugh classification assesses surgical risk in cirrhotic patients. Class C (severe) cirrhosis carries a perioperative mortality of 50 to 80%, and elective surgery should be avoided in these patients. Coagulopathy from decreased clotting factor production requires PT/INR monitoring and may necessitate fresh frozen plasma or vitamin K administration. Thrombocytopenia from splenic sequestration may require platelet transfusion if counts fall below 50,000 for surgery. Drug metabolism is reduced, with decreased clearance of benzodiazepines, opioids, and other hepatically metabolized drugs requiring dose adjustments. Hepatotoxic agents, particularly excess acetaminophen and halothane, should be avoided.

## Renal Disease

Chronic kidney disease stages 3 through 5 (GFR less than 60 mL/min) requires dose adjustment of renally cleared medications. For patients with end-stage renal disease on dialysis, surgery should be scheduled on the day after dialysis, and electrolytes (especially potassium) must be checked preoperatively. Nephrotoxic agents including NSAIDs, aminoglycosides, and IV contrast without pre-hydration should be avoided. The bleeding tendency from uremic platelet dysfunction may require desmopressin (DDAVP) 0.3 mcg/kg IV. The dialysis access site must be protected by avoiding blood pressure cuffs, IV access, or blood draws on the AV fistula arm.

![Flowchart for perioperative medication management in diabetic patients undergoing OMFS procedures](images/diabetic-perioperative-management.jpg)

## Adrenal Insufficiency and Steroid-Dependent Patients

Patients on chronic corticosteroids (greater than 5 mg prednisone per day for greater than 3 weeks) may have hypothalamic-pituitary-adrenal (HPA) axis suppression. During surgical stress, this places them at risk of adrenal crisis, which manifests as hypotension and cardiovascular collapse. The stress-dose steroid protocol calls for hydrocortisone 100 mg IV at induction with a taper over 24 to 48 hours for moderate procedures. For minor procedures under local anesthesia, the patient's usual daily dose is generally sufficient. A detailed discussion is provided in Lecture 73.

## Immunocompromised Patients

For patients with HIV/AIDS, a CD4 count less than 200 increases infection risk and coordination with infectious disease is recommended, though no modification is needed for dental procedures in well-controlled patients. Organ transplant patients on immunosuppressive regimens such as tacrolimus, cyclosporine, and mycophenolate face increased infection risk and potential drug interactions with antibiotics and antifungals. Chemotherapy patients with neutropenia (ANC less than 1,500) have increased infection risk, and elective procedures should be deferred until ANC recovery, with platelet counts greater than 50,000 required for surgery. Patients on bisphosphonates or denosumab are at risk for medication-related osteonecrosis of the jaw (MRONJ), which is discussed in a dedicated lecture.

## Pregnancy

Elective surgery should be deferred to the postpartum period, while emergency surgery is performed with appropriate precautions at any gestational age. The safest period for semi-elective surgery is the second trimester (weeks 14 to 28). Safe medications include lidocaine with epinephrine, acetaminophen, penicillins, and cephalosporins. Medications to avoid include NSAIDs (especially in the third trimester), tetracyclines, benzodiazepines (first trimester), and nitrous oxide (first trimester). Pregnant patients should be positioned in a left lateral tilt after 20 weeks of gestation to prevent supine hypotensive syndrome from aortocaval compression.

## Clinical Pearls

ASA classification determines the appropriate anesthetic setting, with ASA III and IV patients generally requiring hospital-based care. Beta-blockers and statins should be continued perioperatively, while ACE inhibitors and ARBs are held on the day of surgery. SGLT2 inhibitors should be held 3 to 4 days before surgery due to the risk of euglycemic diabetic ketoacidosis. Patients on chronic corticosteroids need stress-dose supplementation for moderate and major procedures. Potassium should always be checked in dialysis patients before surgery, as hyperkalemia can cause fatal arrhythmias.

![Summary table of perioperative medication management for common comorbidities in OMFS patients](images/perioperative-medication-summary.jpg)

## References

1. Fleisher LA, et al. "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery." *Journal of the American College of Cardiology*. 2014;64(22):e77-e137.
2. Joshi GP, Chung F, Vann MA. "Society for Ambulatory Anesthesia Consensus Statement on Perioperative Blood Glucose Management." *Anesthesia and Analgesia*. 2010;111(6):1378-1387.
3. Little JW, et al. *Dental Management of the Medically Compromised Patient*. 9th ed. Elsevier; 2017.
4. Dhatariya K, et al. "Joint British Diabetes Societies Guideline for the Management of Diabetes During Surgery." *Diabetic Medicine*. 2022;39(6):e14856.