Meta-analysis of N-acetylcysteine to prevent acute renal failure after major surgery.
BACKGROUND
Acute renal failure after major surgery is associated with significant mortality and morbidity that theoretically may be attenuated by N-acetylcysteine.


METHODS
Meta-analysis of relevant studies sourced from the Cochrane Controlled Trial Register (2007 issue 4), EMBASE, and MEDLINE databases (1966 to February 1, 2008) without language restriction.


METHODS
Adult patients undergoing major surgery without the use of radiocontrast.


METHODS
Randomized controlled studies comparing N-acetylcysteine with a placebo perioperatively.


METHODS
Categorical variables are reported as odds ratio (OR) with 95% confidence interval (CI), and continuous variables are reported as weighted-mean-difference (WMD) with 95% CI.


METHODS
Effects of N-acetylcysteine on mortality and acute renal failure requiring dialysis were the main outcomes of interest. Additional outcome measures included an incremental increase in serum creatinine concentration greater than 25% above baseline, surgical reexploration for bleeding, amount of allogeneic blood transfusion, and length of intensive care unit stay.


RESULTS
10 studies involving a total of 1,193 adult patients undergoing major surgery were considered. N-Acetylcysteine use was not associated with a decrease in mortality (OR, 1.05; 95% CI, 0.58 to 1.92), acute renal failure requiring dialysis (OR, 1.04; 95% CI, 0.45 to 2.37), incremental increase in serum creatinine concentration greater than 25% above baseline (OR, 0.84; 95% CI, 0.64 to 1.11), or length of intensive care unit stay (WMD in days, 0.46; 95% CI, -0.43 to 1.36). N-acetylcysteine did not appear to increase the risk of surgical reexploration for bleeding (OR, 1.16; 95% CI, 0.57 to 2.38) or amount of allogeneic blood transfusion required (WMD in units, 0.31; 95% CI, -0.21 to 0.84).


CONCLUSIONS
Most studied patients had cardiac surgery and normal renal function preoperatively.


CONCLUSIONS
There is no current evidence that N-acetylcysteine used perioperatively can alter mortality or renal outcomes when radiocontrast is not used.
Ho
Kwok M
KM
Intensive Care Unit, Royal Perth Hospital, Perth, WA 6000, Australia. kwok.ho@health.wa.gov.au
Morgan
David J R
DJ
D000111:Acetylcysteine / Q000627:therapeutic use*; D058186:Acute Kidney Injury / Q000097:blood / Q000401:mortality / Q000517:prevention & control*; D000328:Adult; D013504:Cardiovascular Surgical Procedures; D003404:Creatinine / Q000097:blood; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D011183:Postoperative Complications / Q000097:blood / Q000401:mortality / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic
D003404:Creatinine; D000111:Acetylcysteine