The effect of N-acetylcysteine on blood coagulation and platelet function in patients undergoing open repair of abdominal aortic aneurysm

Abstract

N-acetylcysteine (NAC) may offer renal and hepatic protection during surgery, but in experimental studies it has been shown to impair coagulation. Since very little is known about the effects of NAC on blood coagulation in surgical patients, we studied its effects during abdominal aortic reconstruction. NAC (a bolus of 150 mg/kg followed by a continuous 24-h infusion of 150 mg/kg) or the same volume of placebo was given intravenously, in a randomized double-blinded fashion, to 20 patients undergoing abdominal aortic aneurysm repair. The haematocrit, platelet count, prothrombin time, thromboelastometry, and platelet aggregation were studied during and after surgery. Total blood loss was also measured. The median (25th-75th percentiles) decrease of the prothrombin time value was 33.0% (30-37%) after NAC treatment and 6.5% (4-8%) after placebo (P<0.001). Postoperative prothrombin time values remained lower in the patients receiving NAC. In thromboelastometry tracings the coagulation time was more prolonged after the bolus of NAC (P=0.02). Platelet aggregation induced with adenosine diphosphate decreased after NAC but not after placebo. Low prothrombin time values before and after bolus infusions were associated with increased blood loss (P=0.008 and P=0.015, respectively). NAC has anticoagulant and platelet-inhibiting properties in patients undergoing major vascular surgery. This abnormal haemostatic activity should be considered when NAC is administered to patients with increased bleeding risk.

The addition of MESNA in vitro prolongs prothrombin time similar to N-acetyl cysteine

“…Moreover, TEM allows a coagulation assessment from a more functional point of view than the standard coagulation test and, consequently, nearest to e298 Blasi et al: MESNA coagulation thromboelastometry the clinical situation. In previous series from cardiovascular surgery, NAC prolonged the CT [10]. We did not see this effect with MESNA but the clinical context and the use of heparin can account for this discrepancy.…”

The role of N-acetylcysteine in the treatment of thrombotic thrombocytopenic purpura

“…However, a potential increased risk for bleeding associated with NAC use has been suggested. Two recent studies have demonstrated greater blood loss after surgery in patients treated with NAC, which probably results from its inhibitory effect on platelet aggregation and vitamin K-dependent clotting factors [18][19][20][21]. Although Chen et al found no effect on bleeding time in their NACtreated mice, this result need to be interpreted with caution as their model did not resemble an acute attack of TTP, which is associated in most cases with severe thrombocytopenia [6].…”

The effects of melatonin on burn-induced inflammatory responses and coagulation disorders in rats

“…It is expected that agents inhibiting this overproduction exert protective effects on these processes (13). It has been previously reported that antioxidants administered during the post-burn period restore the oxidant-antioxidant balance and attenuate the activated inflammatory response, blood coagulation and tissue injury (14,15).…”