Is a 70-year-old patient with mild chronic kidney disease (stage 3a, estimated glomerular filtration rate (eGFR) 52 mL/min/1.73 m²) and otherwise normal pre‑operative labs cleared for surgery?

Preoperative Clearance Assessment

This 70-year-old patient is cleared for surgery from a laboratory standpoint, with the important caveat that her Stage 3a chronic kidney disease (eGFR 52 mL/min/1.73 m²) requires specific perioperative renal-protective measures and enhanced monitoring.

Laboratory Analysis

Renal Function Assessment

• The creatinine of 1.13 mg/dL falls below the critical threshold of 2.0 mg/dL that defines significantly increased perioperative cardiac and renal risk 1
• The eGFR of 52 mL/min/1.73 m² indicates Stage 3a CKD but remains well above the 30 mL/min/1.73 m² threshold associated with severe perioperative mortality risk 2
• Preoperative creatinine ≥2.0 mg/dL is the established independent risk factor for cardiac complications after major noncardiac surgery; this patient's value of 1.13 mg/dL does not meet this threshold 1, 3
• In patients over 70 years undergoing cardiac surgery, creatinine >2.6 mg/dL dramatically increases chronic dialysis risk, but this patient's level is substantially lower 1

Hematologic Parameters

• The hemoglobin of 14.4 g/dL and hematocrit of 45.0% are well above the 28% threshold associated with increased perioperative ischemia and complications 1
• All complete blood count parameters fall within normal reference ranges, indicating no anemia-related cardiovascular stress 1

Metabolic and Hepatic Function

• Glucose of 97 mg/dL is within normal fasting range and does not suggest uncontrolled diabetes 1
• All liver function tests (AST 21, ALT 17, alkaline phosphatase 65, bilirubin 0.4) are normal 1
• Electrolytes are within acceptable ranges: sodium 144, potassium 4.9, chloride 108 (minimally elevated), bicarbonate 22 1
• The albumin of 4.5 g/dL indicates adequate nutritional status 1

Mandatory Perioperative Renal-Protective Measures

Hemodynamic Management

• Maintain mean arterial pressure (MAP) between 60-70 mmHg intraoperatively, or >70 mmHg if the patient has preexisting hypertension 2
• Implement goal-directed fluid therapy with stroke volume monitoring to optimize cardiac output and preserve renal perfusion 2

Nephrotoxic Agent Avoidance

• Eliminate all NSAIDs for postoperative pain control given the reduced eGFR 3, 2
• Avoid aminoglycosides and minimize or eliminate contrast media exposure 2
• Adjust all medication dosages according to eGFR to prevent drug accumulation 2

Fluid Management

• Provide adequate hydration with isotonic crystalloids (lactated Ringer's preferred) to maintain renal perfusion 2, 4
• Avoid excessive fluid administration that could precipitate pulmonary edema in the setting of reduced renal clearance 4

Enhanced Monitoring Requirements

• Monitor serum creatinine and urine output closely postoperatively 2
• Define acute kidney injury as a rise in creatinine of ≥0.5 mg/dL or ≥25% from baseline within 48 hours 2
• Document preoperative troponin and repeat at 24-48 hours postoperatively for intermediate- and high-risk patients 1

Risk Stratification Context

• This patient has 2-3 perioperative AKI risk factors: age >56 years, female sex, and eGFR <60 mL/min/1.73 m² 2
• Patients with fewer than three risk factors have substantially lower AKI risk (hazard ratio <46) compared to those with six or more factors 2
• The European Society of Cardiology identifies eGFR <60 mL/min/1.73 m² as correlating with major adverse cardiovascular events, warranting heightened vigilance 1, 2

Common Pitfalls to Avoid

• Do not rely solely on serum creatinine; the eGFR provides superior risk assessment by incorporating age, sex, and body surface area 1, 3
• Do not discontinue ACE inhibitors or ARBs if prescribed for heart failure or diabetic kidney disease, as small creatinine elevations are not an indication for cessation 1, 2
• Do not proceed without calculating and documenting the eGFR, as serum creatinine alone misses up to 25% of patients with significantly reduced kidney function 5