The kidneys may be damaged during an operation as a result of direct and indirect insult. The reasons for this are multiple and include changes to physiology brought on by the surgery and by the body’s response to such insult. Damage to kidneys during the perioperative period is associated with significant morbidity and mortality. This updated Cochrane review looked at 72 randomized controlled trials (RCTs) with 4378 participants (search data until August 2012); interventions most often included pharmacological interventions (administration of dopamine and its analogues, diuretics, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, N-acetyl cysteine, atrial natriuretic peptide, sodium bicarbonate, antioxidants and erythropoietin) or selected hydration fluids. We attempted to identify any possible damage to the kidneys by evaluating kidney function up to seven days after the operation.
No clear evidence from available RCTs suggests that any of the measures used to protect the kidneys during the perioperative period are beneficial. These findings held true in 14 studies of patients with pre-existing renal damage and in 24 studies that were considered of good methodological quality. The primary outcomes of these studies were mortality and acute renal injury. Reported mortality in studies with low risk of bias was not different between intervention and control groups (odds ratio (OR) 1.01, 95% confidence interval (CI) 0.52 to 1.97) or for acute renal injury (OR 1.05, 95% CI 0.55 to 2.03). The summary of findings revealed a similar picture. So we conclude that evidence suggests that none of the interventions used currently are helpful in protecting the kidneys during the perioperative period, nor do they cause increased harm.