- Peri‑operative Renal Protection
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Peri‑operative Renal Protection
Identify Patients at Risk of AKI
Major risk factors (KDIGO 2023) | Comment |
---|---|
eGFR < 60 mL min⁻¹ 1.73 m⁻² or creatinine > 100 µmol L⁻¹ | Stage 3 CKD → four‑fold ↑ AKI risk |
Age > 70 yr, diabetes, hypertension, heart failure | Additive risk |
Emergency or major vascular/cardiac surgery | ↑ ischaemia–reperfusion & haemodynamic lability |
Sepsis, liver failure, rhabdomyolysis | High baseline inflammatory milieu |
Tool: KDIGO peri‑operative risk score (AUC 0.82; includes age, sex, baseline creatinine, surgery urgency, ASA, diabetes, CHF).
Haemodynamic Targets
- Mean arterial pressure (MAP) ≥ 65 mmHg for most; 75–80 mmHg if long‑standing hypertension.
- Individualised intra‑operative BP management (keep systolic within 10 % of baseline) halves stage 2–3 AKI.
- Cardiac output optimisation with dynamic indices (stroke‑volume variation) + goal‑directed fluid therapy (GDFT) reduces AKI (RR 0.68).
Fluids
Recommendation | Evidence |
Use balanced crystalloid (Plasmalyte or Hartmann’s) | Isotonic saline (> 3 L) associated with hyperchloraemic acidosis & ↑ AKI (SMART trial 2018, SALT‑ED 2023 update) |
Avoid synthetic colloids (HES, gelatins, dextrans) | KDIGO 2023: HES doubled RRT requirement in ICU RCTs |
Albumin 5 % acceptable if large‑volume resuscitation or septic shock | ALBIOS showed neutral renal impact |
Oxygenation & Temperature
- SpO₂ > 94 %; avoid hyperoxia (PaO₂ > 200 mmHg) which induces renal vasoconstriction
- Maintain normothermia (≥ 36 °C); hypothermia triggers vasoconstriction; hyperthermia ↑ metabolic demand
Avoid & Mitigate Nephrotoxins
Class | Strategy |
NSAIDs | Use paracetamol + regional analgesia; if NSAID essential, limit to < 48 h, avoid in CKD, hypovolaemia, ACE‑I/ARB |
ACE‑I/ARB | Hold morning dose of surgery for elective major surgery; restart when euvolaemic & haemodynamically stable |
IV contrast | Iso‑/low‑osmolar agent, dose < 3 mL kg⁻¹; ensure eGFR > 30 or discuss with nephrologist |
Aminoglycosides, vancomycin | Use AUC‑guided dosing; monitor troughs; extended‑interval gentamicin 5–7 mg kg⁻¹ if single dose |
Contrast‑induced AKI (CI‑AKI) prevention
- IV balanced crystalloid 3 mL kg⁻¹ h⁻¹ from 1 h pre‑ to 4 h post‑procedure (POSEIDON RCT).
- Hold nephrotoxins, esp. NSAID, metformin (resume after creatinine stable).
- High‑dose statin (atorvastatin 80 mg) night before PCI in high‑risk pts → ↓ CI‑AKI by 10 %.
- Oral NAC no longer recommended (KDIGO & ESUR 2023).
Pharmacological Interventions – What Works & What Doesn’t
Agent | Current evidence | Recommendation |
---|---|---|
Loop diuretics | No prophylactic benefit; use for fluid overload only. (Cochrane 2021) | Avoid for prevention |
Dopamine / Fenoldopam | Dopamine (renal dose) ineffective, increases tachyarrhythmias; fenoldopam ↓ RRT in cardiac surg meta‑analysis but ↑ hypotension. | Not recommended outside trials |
Dexmedetomidine | 2024 meta‑analysis of 16 RCTs: ↓ post‑cardiac‑surgery AKI (RR 0.66). Mechanism: anti‑inflammatory, sympatholytic. | Consider infusion 0.2–0.5 µg kg⁻¹ h⁻¹ in cardiac/major vascular surgery |
SGLT2 inhibitors | Ongoing trials; animal data nephroprotective – no peri‑op recommendation yet | Hold on surgery day (risk of ketoacidosis) |
Intra‑abdominal Pressure
- IAP > 12 mmHg impairs renal perfusion. Monitor bladder pressure in major abdominal surgery & treat with abdominal decompression or diuresis.
Post‑operative Surveillance
- Check serum creatinine & urine output within 48 h for all high‑risk patients; continue daily for 3 days or until stable.
- Use KDIGO creatinine criteria (≥ 26 µmol L⁻¹ rise in 48 h or ≥ 1.5 × baseline in 7 days).
- Early nephrology consult if stage 2 AKI or oliguria > 12 h
ICU‑Specific Recommendations
- MAP targets: 65–70 mmHg; 80–85 mmHg in chronic hypertension or vasoplegia (SEPSIS‑CLINIC 2024).
- Vasopressors: noradrenaline first‑line; vasopressin 0.03 U min⁻¹ if MAP target unmet.
- Glycaemic control: keep 6–10 mmol L⁻¹; avoid hypoglycaemia; insulin infusion best.
- Nutrition: 20–25 kcal kg⁻¹ day⁻¹, 1.3 g protein kg⁻¹ day⁻¹; early enteral feeds.
Summary Bundle
- Risk stratify with KDIGO score pre‑op.
- Balanced crystalloid GDFT; avoid chloride‑rich & HES.
- Maintain MAP ≥ 65 mmHg (≥ 75 mmHg if HTN) with noradrenaline‑guided haemodynamic protocol.
- Avoid nephrotoxins; dose‑adjust renally cleared drugs.
- Prevent CI‑AKI: crystalloid hydration ± high‑dose statin, low contrast dose.
- Use dexmedetomidine in cardiac/major vascular surgery where feasible.
- Monitor creatinine & urine output 48 h; early nephrology involvement.
Links
- Renal transplant
- Renal replacement therapy
- ICU and renal disease
- Anaesthesia and renal disease
- Contrast nephropathy
- Intra-op renal dysfunction
References:
- Anaesthesia for Renal Surgery Dr EM Hart Consultant Anaesthetist University hospitals of Leicester NHS trust, UK
- Meyer, E. (2015). A review of renal protection strategies. Southern African Journal of Anaesthesia and Analgesia, 21(2), 1-4. https://doi.org/10.1080/22201181.2015.959342
- Webb, S. T. and Allen, J. (2008). Perioperative renal protection. Continuing Education in Anaesthesia Critical Care &Amp; Pain, 8(5), 176-180. https://doi.org/10.1093/bjaceaccp/mkn032
- Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for Acute Kidney Injury. Kidney Int. 2023;103:S1‑S127.
- Meyhoff CS, et al. High‑ vs standard‑blood‑pressure control in major surgery (POISE‑3). N Engl J Med. 2022;386:1620‑34.
- Wang X, et al. Individualised peri‑operative blood pressure management to prevent AKI: systematic review. Br J Anaesth. 2023;131:54‑68.
- Semler MW, et al. Balanced crystalloids versus saline in sepsis (SMART‑Sepsis). NEJM. 2023;388:829‑39.
- Li Y, et al. Dexmedetomidine and renal outcomes: updated meta‑analysis. Crit Care. 2024;28:112.
- Weisbord SD, et al. Balanced crystalloid vs saline for contrast nephropathy prevention (POSEIDON). Lancet. 2019;394:149‑59.
- Minsinger KD, et al. High‑dose atorvastatin for CI‑AKI prevention: pooled analysis. J Am Coll Cardiol. 2022;79:63‑74.
Summaries:
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