Anaesthesia in chronic dialysis patients: A narrative review

Table 1 Pharmacologic considerations for common anaesthesia agents in chronic dialysis patients

Drug	Dose change in renal Impairment	Dialysable	Comments
Sedatives
Propofol	-	No	Metabolized by the liver. No dose adjustment is necessary for any degree of renal impairment[4-7]. Because metabolites theoretically accumulate with longer infusions, vigilance is advised
Ketamine	-	No	Metabolized by the liver. No dose adjustment is necessary for any degree of renal impairment
Thiopentone	↓	No	Predominantly undergoes hepatic metabolism with urinary excretion of metabolites. Dose must be reduced by 25%-30%[8]. Clearance via haemodialysis is negligible[9]
Etomidate	-	Unknown	Rapid metabolism in the liver and plasma. No dose adjustment is necessary
Midazolam	↓	No	Predominantly undergoes hepatic metabolism with urinary excretion of metabolites. Boluses can be administered without any dose adjustment[10]. Continuous infusions require lowered doses. Metabolites accumulate with extended use, resulting in a prolonged half-life and sedative effect[11-13]. However, the effect is inconsistent with significant interpersonal variability
Volatile Gases	-	Unknown	Primarily eliminated via exhalation (e.g. halothane, desflurane, sevoflurane); renal excretion is minor. No dose adjustment is necessary for any degree of renal impairment[6,14,15]
Analgesics
Morphine	↓	Yes	Metabolized through hepatic glucuronidation with urinary elimination of metabolites. Morphine metabolites accumulate with renal dysfunction, resulting in a prolonged half-life. A 75% reduction is recommended for both bolus and infusion doses[16-18]. No opioids are dialysable in subjects with preserved kidney function because intrinsic clearance exceeds the rate of removal via dialysis. Morphine is considered dialysable in those with advanced kidney impairment; however, extracorporeal removal is rarely indicated in practice due to the success of supportive care and naloxone as an antidote[3]
Oxycodone	↓	Yes	Undergoes hepatic glucuronidation. Metabolites accumulate with renal impairment. Dose should be reduced by 25%-50%
Fentanyl	-	No	Hepatic metabolism followed by mainly urinary clearance. Because of its short half-life, accumulation occurs only with continuous use. No dose adjustments are required for bolus dosing[19]. Continuous infusion doses should be reduced by approximately 25-50%[17,20]
Remifentanil	-	No	Rapidly metabolized by blood and tissue enzymes, with metabolites excreted in the urine. No dose adjustment is necessary
Paralytics
Suxamethonium	-	Unknown	Suxamethonium is hydrolyzed rapidly and undergoes minimal urinary excretion. No dose adjustments are required. Be aware of the risk of hyperkalaemia
Rocuronium	-	Unknown	Undergoes hepatic metabolism followed by biliary and renal excretion. No dose adjustments are typically recommended in patients with renal impairment; however, this interaction is poorly understood. In some experimental studies of patients with renal failure, clearance was reduced by a third and half-life was extended by up to 50%. Therefore, rocuronium is best avoided where prolonged paralysis is undesirable[21-23]. Sugammadex reversal is contraindicated due to insufficient safety data in chronic dialysis patients
Cisatracurium	-	Unknown	No dose adjustment is necessary. Although the half-life is nominally increased in kidney failure, cisatracurium is rapidly metabolized via Hofmann degradation
Regional Anaesthetics
Lidocaine	-	No	No dose adjustments for kidney function are required when used for local or regional anaesthesia. Spinal and epidural regional anaesthesia, such as with ropivicaine or bupivacaine, appears safe in chronic dialysis patients[24,25]

Table 2 Perioperative medical management of the chronic dialysis patient

Medical issue	Practice points
Glycaemic control	The perioperative blood glucose goal is usually between about 5-10mmol/L[55]. Guidelines recommend a glycaemic target of 7.8-10 mmol/L for critically ill adults[56]. Pre-existing insulin and oral anti-hyperglycaemic drugs are frequently withheld or reduced
Antihypertensives	Blood pressure targets are uncertain. Usually continued perioperatively and during acute illness unless hypotension is problematic
Antithrombotics	There should be an antithrombotic medication management plan where feasible. The intention is to balance the risk of surgical bleeding if the antithrombotic is continued with the risk of thromboembolism if withheld. Due to the complexity of decision-making, guidelines and local policies should be followed
Bleeding reversal and transfusions	Spontaneous and postoperative bleeding rates are significantly increased. Bleeding diathesis is predominantly explained by uraemic platelet dysfunction and the frequent use of anti-thrombotic medications. Haemodialysis reduces the bleeding time and prevents haemorrhagic complications[54]. Options to reverse acute haemorrhage include intravenous calcium, desmopressin, and tranexamic acid, and acute haemodialysis; however, clinical studies are scant. Consider empiric protamine where heparins are used for anticoagulation in dialysis. Transfusion protocols guided by bedside viscoelastic assays are advocated but have not been studied in this context. Erythropoietin-stimulating agents have no role in acute anaemia management. Where a blood transfusion is necessary in a potential candidate for kidney transplantation, leukocyte-depleted allogenic red blood cells are preferred
Neuraxial anaesthetic blocks	Renal impairment is associated with a slightly increased risk of epidural haematoma with neuraxial procedures[58], but objective data are scarce. The approach to regional anaesthesia relies on clinician judgement and standard anaesthesia and preoperative guidelines[38]. Experts recommend ensuring a low plasma urea and heparin-free dialysis near the time of the procedure

Table 3 Common dialysis access procedures

Surgical procedure	Technical notes	Anaesthetic techniques
Arteriovenous fistula creation	Surgical construction of a connection between an artery and vein to enable repeated cannulation for chronic haemodialysis. Typically in the upper limb. Elective procedure	Local anaesthesia. Regional anaesthesia (e.g. brachial plexus block). Sedation or general anaesthesia
Tunnelled haemodialysis catheter insertion	Insertion of a central venous catheter, usually in the internal jugular vein, which is tunnelled through a subcutaneous tract. Similar to a standard uncuffed central venous line placement. Urgent or elective procedure	Local anaesthesia. Sedation
Peritoneal dialysis catheter insertion	Implantation of a catheter into the peritoneal cavity, which is then tunnelled through a subcutaneous tract. Both surgical and percutaneous radiologic methods are used. Elective procedure	Local anaesthesia. Sedation or general anaesthesia