Perioperative Management for Patients with Reduced Kidney Function

Risk Stratification

An eGFR <60 mL/min/1.73 m² correlates significantly with major adverse cardiovascular events, including myocardial infarction, stroke, and heart failure progression, according to the European Society of Cardiology 1, 2
Even temporary worsening of renal function increases 30-day mortality 3.7-fold, while persistent worsening increases it 7.3-fold, as reported by the European Heart Journal 3, 4
Additional risk factors that compound perioperative acute kidney injury include age >56 years, emergency surgery, active heart failure, ascites, hypertension, intraperitoneal surgery, and diabetes, as stated by the European Society of Cardiology 1

Calculate precise renal function using the CKD-EPI formula and assess urinary albumin-creatinine ratio, as recommended by the European Society of Cardiology 2, 5
Adjust all medication dosages according to eGFR to prevent drug accumulation and toxicity, with specific guidance on opioid use from the Mayo Clinic 6
Continue ACE inhibitors or ARBs if prescribed for diabetic kidney disease or albuminuria, as advised by the American College of Cardiology 7, 5

Maintain mean arterial pressure (MAP) between 60-70 mmHg, or >70 mmHg if the patient has pre-existing hypertension, as recommended by the American Society of Anesthesiologists 8, 7, 5
Implement goal-directed fluid therapy with stroke volume monitoring to optimize cardiac output and maintain adequate renal perfusion pressure, as suggested by the European Society of Anesthesiology 8, 7, 5

Eliminate or minimize all nephrotoxic medications, including NSAIDs, aminoglycosides, and contrast media, as advised by the National Kidney Foundation 8, 7, 5

Hydrate with isotonic saline or sodium bicarbonate before and after contrast-enhanced procedures, as recommended by the European Society of Cardiology 3, 4, 7, 5
Consider N-acetylcysteine as an adjunct to hydration, although evidence for benefit remains inconclusive, as reported by the European Heart Journal 2, 3, 7

Monitor renal function closely with regular assessment of urine output, serum creatinine, and define acute kidney injury as a rise in serum creatinine of 44 μmol/L (0.5 mg/dL) or 25% relative rise from baseline within 48 hours, as recommended by the American College of Cardiology 1, 7, 5
Maintain adequate hydration and continue avoiding nephrotoxic medications in the postoperative period, as advised by the American Society of Anesthesiologists 8, 5

Elevated pre‑operative serum creatinine (≥ 2 mg/dL) or estimated GFR < 60 mL/min/1.73 m² is the strongest predictor of peri‑operative renal dysfunction and markedly raises short‑ and long‑term morbidity and mortality. (American College of Cardiology & American Heart Association) [9][10]
A pre‑operative creatinine level ≥ 2 mg/dL independently predicts cardiac and renal complications after major non‑cardiac surgery. (American College of Cardiology & American Heart Association) [9][10]
In elderly patients (> 70 years) undergoing cardiac surgery, a pre‑operative creatinine > 2.6 mg/dL dramatically increases the likelihood of requiring chronic dialysis post‑operatively compared with lower values. (American College of Cardiology & American Heart Association) [9][10]11
Azotemia, frequently co‑existent with cardiac disease, is linked to a higher incidence of adverse cardiovascular events. (American College of Cardiology & American Heart Association) [9][10]11

Major vascular surgery is associated with a significantly higher risk of postoperative renal complications. (American College of Cardiology & American Heart Association) [9][10]

Aggressive diuresis combined with the initiation of ACE‑inhibitors or angiotensin‑receptor blockers can provoke rises in blood urea nitrogen and serum creatinine, indicating acute renal stress. (American College of Cardiology & American Heart Association) [9][10]11

Creatinine clearance, which incorporates serum creatinine, age, and body weight, provides a more precise estimate of renal function than serum creatinine alone. (American College of Cardiology & American Heart Association) [9][10]11
The American Heart Association recommends using the Modification of Diet in Renal Disease (MDRD) equation to calculate estimated GFR for peri‑operative risk stratification. (American College of Cardiology & American Heart Association) [9][10]11

Diabetic nephropathy develops in roughly 30 % of individuals with type 1 diabetes and about 20 % of those with type 2 diabetes, representing the leading cause of end‑stage renal disease. (Anaesthesia Society) 12

Age greater than 56 years independently increases the risk of postoperative AKI. 13
Male sex is associated with a significantly higher incidence of peri‑operative AKI. 14
Pre‑operative elevation of serum creatinine is one of the strongest predictors of peri‑operative renal dysfunction. 15
An estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m² correlates with major adverse cardiovascular events and renal complications. 13
Active heart failure markedly raises the likelihood of postoperative AKI. 14
Treated arterial hypertension contributes to an increased risk of peri‑operative AKI. 15
Clinical evidence of ascites reflects compromised hemodynamics that predisposes to AKI. 13
Diabetes mellitus independently elevates AKI risk, especially when accompanied by pre‑existing renal impairment. 14

Emergency (urgent) surgical procedures dramatically heighten the risk of peri‑operative AKI. 15
Intraperitoneal operations are linked to a higher incidence of postoperative AKI. 13

Exposure to iodinated contrast agents can cause CIN in up to 15 % of patients with chronic kidney disease. 15
Key risk factors for CIN include procedural urgency, baseline renal function, diabetes, and the volume of contrast administered. 15
CIN is defined as an increase in serum creatinine of ≥0.5 mg/dL (≈44 µmol/L) or a relative rise of ≥25 % from baseline within 48 hours after contrast exposure. 15

Renal function should be estimated using the CKD‑EPI equation, which incorporates sex, age, ethnicity, and serum creatinine concentration. 13
Proteinuria assessment should employ the urine albumin‑to‑creatinine ratio. 14

Patients presenting with six or more of the identified risk factors (age > 56 y, male sex, active heart failure, ascites, hypertension, emergency surgery, intraperitoneal surgery, elevated pre‑operative creatinine, diabetes) experience a 10 % incidence of peri‑operative AKI and a hazard ratio of 46 compared with those having fewer than three risk factors. 13
Development of AKI after major surgery reduces long‑term survival even in individuals with normal baseline renal function. 14