Perioperative Medicine: The Hospitalist's Pre-Operative Risk Assessment and Optimization

Dr Neeraj Manikath , claude.ai

Abstract

The perioperative consultation has evolved from a simple "yes/no clearance" to a comprehensive risk stratification and optimization process. Hospitalists are increasingly called upon to provide structured perioperative assessments that guide surgical decision-making and reduce complications. This review focuses on evidence-based approaches to cardiac risk stratification using the Revised Cardiac Risk Index (RCRI), perioperative medication management including anticoagulation bridging strategies, glycemic optimization, and the creation of actionable clearance documentation that meaningfully impacts patient outcomes.

Introduction

Approximately 14.4 million inpatient and 19.2 million ambulatory surgeries are performed annually in the United States, with cardiovascular risk factors present in 45% of surgical inpatients aged ≥45 years. The traditional concept of "medical clearance" is fundamentally flawed—surgery is never without risk, and our role is not to grant permission but rather to quantify risk, optimize modifiable factors, and communicate actionable recommendations to the surgical and anesthesia teams. This paradigm shift transforms the hospitalist from gatekeeper to consultant, from binary decision-maker to risk stratifier and optimizer.

The Revised Cardiac Risk Index (RCRI): Foundation of Risk Stratification

Historical Context and Validation

The Revised Cardiac Risk Index, developed by Lee and colleagues in 1999 from 2,893 patients undergoing major noncardiac surgery, identified six independent predictors of perioperative cardiac complications. The RCRI superseded Goldman's original 1977 index by being both simpler to use and more accurate in clinical practice.

The Six Risk Factors

Each of the following carries equal weight (1 point each):

High-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular procedures)
History of ischemic heart disease (prior MI, positive stress test, current chest pain, Q waves on ECG, or nitrate therapy)
History of congestive heart failure (pulmonary edema, S3 gallop, bilateral rales, or paroxysmal nocturnal dyspnea)
History of cerebrovascular disease (prior stroke or transient ischemic attack)
Diabetes mellitus requiring insulin therapy
Chronic kidney disease (serum creatinine >2.0 mg/dL or 177 μmol/L)

Risk Stratification Outcomes

RCRI score correlates with perioperative cardiac risk: 0 points = <1% risk; 1 point = 1.3% risk (low); 2 points = 4-7% risk (intermediate); ≥3 points = 9-11% risk (high).

Pearl: The 2024 AHA/ACC guidelines define elevated risk as ≥1% risk of major adverse cardiovascular events (MACE), traditionally corresponding to RCRI >1.

Limitations and Clinical Application

Oyster #1: The RCRI was derived from a diverse patient population where vascular procedures comprised only one-fifth of the cohort. Recent validation studies in chronic kidney replacement therapy patients showed the RCRI overestimated risk and performed poorly in this population, highlighting that one size does not fit all.

Clinical Hack: Don't just calculate the score—interpret it in context. A 45-year-old diabetic with an RCRI of 2 undergoing laparoscopic cholecystectomy represents different risk than a 75-year-old with the same score undergoing open abdominal aortic aneurysm repair, even though the surgery is already factored into the RCRI.

Medication Management: The Hold vs. Continue Decision Matrix

Beta-Blockers and Statins: Continue for Most

Beta-Blockers: Continue beta-blockers for patients already taking them; do not initiate within a week of surgery. Abrupt withdrawal risks rebound tachycardia, hypertension, and myocardial ischemia. For patients with heart failure, coronary artery disease, or arrhythmias requiring beta-blockade, continuation is essential.

Statins: Statins demonstrate perioperative cardiovascular risk reduction through pleiotropic effects including endothelial optimization, plaque stabilization, and anti-inflammatory properties—effects that occur within hours to days. Continue statins throughout the perioperative period.

Pearl: The old package inserts recommending statin discontinuation are outdated and wrong. Maintain statins even on the morning of surgery.

ACE Inhibitors and ARBs: The Hypotension Conundrum

ACE inhibitors and ARBs have been associated with perioperative hypotension. Expert opinion increasingly supports holding these medications on the day of surgery, reassessing on postoperative day 1, and resuming when hemodynamically stable.

Hack: For patients with heart failure where ACEI/ARBs are critical, coordinate with anesthesia—they can manage intraoperative hypotension with vasopressors rather than risk decompensation from medication discontinuation.

Oral Hypoglycemics: The New Risk Landscape

Metformin: While once feared for lactic acidosis risk, metformin-associated lactic acidosis is exceedingly rare. Guidelines now vary: some recommend holding metformin on the day of surgery; others allow continuation for less invasive procedures or when normal oral intake is expected the same day. Hold for 24-48 hours if renal impairment (eGFR <45 mL/min/1.73 m²) or contrast administration is planned.

SGLT2 Inhibitors (Empagliflozin, Dapagliflozin, Canagliflozin): This class presents significant perioperative risk. SGLT2 inhibitors can cause euglycemic diabetic ketoacidosis in the perioperative period; FDA recommendations specify holding these medications at least 3-4 days preoperatively.

Oyster #2: Euglycemic DKA means the patient develops ketoacidosis with glucose levels that may be normal or only mildly elevated (<200-250 mg/dL), making diagnosis challenging. SGLT2 inhibitors should be withheld for 2-3 days before elective surgery and resumed only when adequate oral intake is established postoperatively.

Clinical Hack (SSTOP Mnemonic): Stop SGLT2 inhibitor Three days bef-Ore Procedures. Resume only when eating and drinking normally.

Sulfonylureas: Hold on the day of surgery due to hypoglycemia risk during fasting periods.

GLP-1 Receptor Agonists: For ambulatory surgery, hold weekly formulations for one week and daily oral formulations on the day of surgery.

Anticoagulation and Bridging: The CHADS-VASc Decision Matrix

The Paradigm Shift: Less is More

The landmark BRIDGE trial fundamentally changed perioperative anticoagulation management. Perioperative bridging with low-molecular-weight heparin was associated with three times higher major bleeding (3.2% vs 1.3%) without reduction in thromboembolic events.

Risk Stratification Using CHADS-VASc

The CHA₂DS₂-VASc score assesses stroke risk in atrial fibrillation:

Congestive heart failure (1 point)
Hypertension (1 point)
Age ≥75 years (2 points)
Diabetes (1 point)
Stroke/TIA/thromboembolism (2 points)
Vascular disease (prior MI, PAD, aortic plaque) (1 point)
Age 65-74 years (1 point)
Sex category (female) (1 point)

The Bridging Decision Algorithm

Low Risk (CHA₂DS₂-VASc ≤4, no prior stroke/TIA):

Discontinue warfarin 5 days before procedure
NO bridging anticoagulation
Resume warfarin postoperatively when hemostasis is secure

Moderate Risk (CHA₂DS₂-VASc 5-6, or prior stroke/TIA >3 months ago):

Consider individual bleeding vs. thrombotic risk
High bleeding risk procedures: No bridging
Low bleeding risk procedures with prior stroke/TIA: Consider bridging

High Risk (CHA₂DS₂-VASc 7-9, stroke/TIA within 3 months, or mechanical valve): Parenteral bridging anticoagulation should be considered for patients at high risk of stroke or systemic embolism (>10% per year) with CHA₂DS₂-VASc 7-9 or recent ischemic stroke, TIA, or systemic embolism.

Pearl: In the BRIDGE trial, the mean CHADS₂ score was 2.3, with <15% having CHADS₂ ≥4. Results cannot be extrapolated to very high-risk patients, so clinical judgment remains paramount.

Direct Oral Anticoagulants (DOACs)

DOACs have short half-lives (8-15 hours), allowing interruption without bridging:

Low bleeding risk procedures: Hold 24 hours before (1-2 half-lives)
High bleeding risk procedures: Hold 48-72 hours before (3-5 half-lives)
Adjust based on renal function (longer holds for renal impairment)
Resume 24-72 hours postoperatively based on bleeding risk

Hack: DOACs are renally cleared to varying degrees. For dabigatran (80% renal clearance), extend the hold period significantly if CrCl <50 mL/min.

Glycemic Control: The 180 mg/dL Target

The Evidence Base

A reasonable perioperative glycemic goal is maintaining blood glucose between 140-180 mg/dL to prevent both hypoglycemia and hyperglycemia. Studies in cardiac, general surgery, and ICU patients demonstrate clear association between hyperglycemia (>180 mg/dL) and adverse outcomes including surgical site infections, delayed wound healing, and increased length of stay.

Preoperative Optimization

Target: For elective surgeries, aim for HbA1c <8% when possible, with blood glucose 100-180 mg/dL four hours before surgery.

Oyster #3: Tight glycemic control (<110 mg/dL) is harmful. A randomized controlled trial maintaining intraoperative glucose 80-100 mg/dL versus treating only if >200 mg/dL reported more deaths and strokes in the intensive treatment group.

Intraoperative Management:

Initiate insulin therapy for intraoperative blood glucose >180 mg/dL
Monitor glucose hourly during procedures
Use subcutaneous rapid-acting insulin every 2 hours for shorter procedures
Use IV insulin infusion for procedures >4 hours or with significant hemodynamic instability

Postoperative Targets:

Maintain glucose <180 mg/dL in non-critically ill patients
Avoid intensive control targeting <110 mg/dL (increased mortality)

Clinical Hack: For every 10-unit increase in blood glucose above 180 mg/dL, there is incrementally increased infection risk. The dose-response relationship means that even modest hyperglycemia (200-250 mg/dL) significantly increases complications.

The "Clearance" Note Template: Creating Actionable Documentation

Moving Beyond Binary Decisions

The traditional clearance note stating "Patient cleared for surgery" provides no value. Your consultation should function as a roadmap for risk management and optimization.

Structured Template Components

1. PROCEDURE AND INDICATION

Planned procedure: [Specific operation]
Scheduled date: [Date]
Surgeon: [Name]
Indication: [Why surgery is needed]

2. CARDIOVASCULAR RISK ASSESSMENT

RCRI Score: [X]/6 points

☐ High-risk surgery (intraperitoneal, intrathoracic, suprainguinal vascular)
☐ History of ischemic heart disease
☐ History of heart failure
☐ History of cerebrovascular disease
☐ Insulin-dependent diabetes
☐ Chronic kidney disease (Cr >2.0 mg/dL)

Estimated Cardiac Risk: [<1% / 1.3% / 4-7% / 9-11%] Risk Category: [Low / Intermediate / High]

Functional Capacity: [Excellent (>10 METs) / Good (7-10 METs) / Moderate (4-7 METs) / Poor (<4 METs)]

Can patient climb two flights of stairs or walk four blocks without stopping? [Yes/No]

3. PERIOPERATIVE MEDICATION MANAGEMENT

CONTINUE:

Beta-blockers: [List medications and doses]
Statins: [List medications and doses]
[Other chronic medications to continue]

HOLD:

Day before surgery: SGLT2 inhibitors (held since [date], 3-4 days before)
Morning of surgery:
- ACE inhibitors/ARBs: [List]
- Metformin: [Dose]
- Sulfonylureas: [List]
- Diuretics: [Consider holding]

ANTICOAGULATION MANAGEMENT:

For Warfarin:

CHA₂DS₂-VASc Score: [X]/9
Annual stroke risk: [Low <5% / Moderate 5-10% / High >10%]
Bridging recommendation: [Not indicated / Consider based on bleeding risk / Recommended]
Hold warfarin 5 days before surgery (last dose: [date])
Target INR <1.5 for surgery
[If bridging]: Start LMWH [dose] when INR <2.0, hold 24 hours before surgery
Resume warfarin [12-24 hours / 24-48 hours / 48-72 hours] postoperatively based on hemostasis

For DOACs:

Medication: [Apixaban/Rivaroxaban/Dabigatran/Edoxaban]
CrCl: [X] mL/min
Hold [24-48/48-72] hours before surgery
No bridging indicated
Resume [24-48/48-72] hours postoperatively

4. GLYCEMIC MANAGEMENT

Preoperative:

Current HbA1c: [X]% (Date: [X])
Target glucose morning of surgery: 100-180 mg/dL
If glucose >180 mg/dL: Notify anesthesia, consider IV insulin

Intraoperative:

Check glucose hourly
Treat glucose >180 mg/dL with insulin
Continue basal insulin at 50-75% of home dose

Postoperative:

Target glucose <180 mg/dL
Resume home regimen when tolerating PO

5. RISK MITIGATION STRATEGIES

[Specific to patient's comorbidities:]

Pulmonary: [Incentive spirometry, early ambulation, bronchodilators]
Cardiac: [Telemetry monitoring, fluid management, continuation of beta-blockers]
Renal: [Minimize nephrotoxins, IV hydration protocols, hold metformin]
VTE prophylaxis: [Pharmacologic and/or mechanical, timing considerations]

6. OPTIMIZATION RECOMMENDATIONS

Completed:

☐ ECG reviewed: [Findings]
☐ Recent labs reviewed: [Abnormalities addressed]
☐ Medication reconciliation completed
☐ Patient education provided

Outstanding (if any):

☐ Further cardiac workup: [Specify if RCRI ≥2 with poor functional capacity]
☐ Anemia optimization: [If Hgb <10 g/dL]
☐ Volume status optimization: [For heart failure]

7. ASSESSMENT AND PLAN

The patient has [LOW/INTERMEDIATE/HIGH] perioperative cardiac risk for the planned [procedure].

Risk Factors Present: [Enumerate specific risk factors]

Recommendation: ☐ Proceed with surgery as scheduled - Risk is acceptable with outlined management ☐ Proceed with optimization - Recommend [specific interventions] prior to surgery ☐ Defer surgery - [Specific reason: uncontrolled acute condition, need for further workup]

Specific Perioperative Recommendations:

[Medication management as outlined above]
[Monitoring: telemetry vs. floor]
[DVT prophylaxis strategy]
[Glycemic management protocol]
[ICU vs. floor postoperative care]

Communication:

Surgeon [Name] contacted on [date/time]
Anesthesia team notified of [specific high-risk features]
Recommendations discussed with patient on [date]

Pearls, Oysters, and Clinical Hacks: Summary

Pearls

RCRI >1 = elevated risk (≥1% MACE) - This is your threshold for enhanced perioperative surveillance and optimization.
Continue statins and beta-blockers perioperatively - The benefits vastly outweigh withdrawal risks.
Most patients don't need bridging - The BRIDGE trial showed bridging triples bleeding risk without reducing strokes in moderate-risk patients.
180 mg/dL is the glycemic target - Higher increases complications, lower increases hypoglycemia and mortality.
Your note should guide management, not just give permission - Provide actionable risk assessment and specific recommendations.

Oysters (Hidden Dangers)

RCRI validation limitations - Overestimates risk in dialysis patients; underrepresents very high-risk populations. Use clinical judgment alongside the score.
Euglycemic DKA from SGLT2 inhibitors - Can occur with "normal" glucose levels, making diagnosis treacherous. Always hold 3-4 days before surgery.
Tight glycemic control (<110 mg/dL) increases mortality - The pendulum has swung away from intensive insulin protocols.
CHADS-VASc score doesn't capture all high-risk features - Prior perioperative stroke, mechanical mitral valve, recent (<3 months) thromboembolic event, and severe rheumatic mitral stenosis warrant bridging consideration regardless of score.

Clinical Hacks

The "4-MET rule": Can the patient climb 2 flights of stairs or walk 4 blocks? If no, they have poor functional capacity and need further cardiac workup if RCRI ≥2.
SSTOP for SGLT2 inhibitors: Stop SGLT2 inhibitor Three days bef-Ore Procedures.
The 5-3-1 warfarin rule: Hold warfarin 5 days before, target INR <1.5, bridge if CHA₂DS₂-VASc ≥7 or stroke within 3 months.
The "double-check glucose" rule: Check glucose both morning of surgery AND on arrival to preoperative area. Hyperglycemia develops rapidly during NPO periods.
Document negative decisions: If you decide NOT to bridge anticoagulation, explicitly state why - this protects you and provides teaching value.
The "optimize vs. cancel" algorithm:
- Acute decompensated heart failure → Cancel
- Uncontrolled atrial fibrillation → Cancel
- HbA1c 9% but glucose 150 mg/dL → Optimize and proceed
- Anemia Hgb 9 g/dL but stable → Optimize and proceed

Conclusion

The perioperative consultation represents one of the hospitalist's most impactful contributions to patient care. By moving beyond binary "clearance" to structured risk stratification, evidence-based medication management, and clear communication of actionable recommendations, we transform surgical outcomes. The RCRI provides the framework for cardiac risk assessment; thoughtful anticoagulation decisions balance thrombosis and bleeding; meticulous glycemic control reduces infections; and comprehensive documentation creates a roadmap for the entire perioperative team.

Remember: you're not clearing patients for surgery—you're quantifying risk, optimizing modifiable factors, and guiding perioperative management to deliver the best possible outcomes. Make every consultation count.

Key References

Lee TH, Marcantonio ER, Mangione CM, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation. 1999;100(10):1043-1049.
Fleisher LA, Fleischmann KE, Auerbach AD, et al. 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery. Circulation. 2024.
Douketis JD, Spyropoulos AC, Duncan J, et al. Perioperative Management of Antithrombotic Therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2022;162(5):e207-e243.
Dhatariya K, Levy N, Kilvert A, et al. Current practice in the perioperative management of patients with diabetes mellitus: a narrative review. British Journal of Anaesthesia. 2023;130(6):e427-e440.
Umpierrez GE, Pasquel FJ. Management of Inpatient Hyperglycemia and Diabetes in Older Adults. Diabetes Care. 2017;40(4):509-517.
Douketis JD, Healey JS, Brueckmann M, et al. Perioperative bridging anticoagulation during dabigatran or warfarin interruption among patients who had an elective surgery or procedure. Thrombosis and Haemostasis. 2015;113(3):625-632.
Kotagal M, Symons RG, Hirsch IB, et al. Perioperative hyperglycemia and risk of adverse events among patients with and without diabetes. Annals of Surgery. 2015;261(1):97-103.

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