Antifibrinolytic Agents in Current Anaesthetic Practice

Abstract

T he widely used first-generation 5-hydroxytryptamine type 3 (5-HT 3 ) receptor antagonists are associated with cardiovascular adverse events. The cause of these complications is thought to be a tendency to block cardiac potassium and sodium ion channels, leading to increasing corrected QT (QTc) intervals. Palonosetron is a second-generation 5-HT 3 receptor antagonist used to prevent postoperative nausea and vomiting (PONV). However, it may prolong the QTc interval and increase the risk of life-threatening arrhythmias. Sevoflurane induces QTc interval prolongation by inhibition of cardiac potassium ion channels similar to the mechanism of the first-generation 5-HT 3 receptor antagonists. If palonosetron and sevoflurane have a combined effect on cardiac ion channels, palonosetron may induce QTc interval prolongation under sevoflurane anesthesia. This prospective, randomized, double-blind study was undertaken to evaluate the effects of palonosetron on QTc intervals in patients having elective surgery under sevoflurane anesthesia.The 100 patients, aged 20 to 75 years, were having elective abdominal or gynecologic surgery with an expected duration of more than 1.5 hours. The presurgery group of 50 patients received 0.075 mg palonosetron intravenously immediately before induction of general anesthesia and 1.5 mL normal saline intravenously immediately after the first postoperative QTc interval was recorded in the recovery room. The postsurgery group of 50 patients received 1.5 mL normal saline before anesthesia induction and 0.075 mg palonosetron intravenously immediately after the first postoperative QTc interval was recorded in the recovery room. Corrected QT intervals were measured before operation, intraoperatively (baseline, immediately after tracheal intubation, and at 2, 10, 25, 30, 60, and 90 minutes after administration of palonosetron or placebo), and after surgery (before and at 3 and 10 minutes after palonosetron or placebo administration). Corrected QT intervals were calculated using Bazett (QTcB), Fridericia (QTcF), or Hodges (QTcH) formulas. The incidence of PONV was assessed at 0 to 2 and 2 to 24 hours after surgery. A complete response was defined as an absence of both emetic episodes and the use of rescue medications for PONV. The primary outcome was the QTcF interval measured immediately after tracheal intubation. SPSS for Windows version 18.0 (SPSS Inc, Chicago, Ill) was used for statistical analyses. P < 0.05 indicated statistical significance.The 2 groups did not differ in patient characteristics or in preoperative QTc intervals on electrocardiograms. Serum electrolyte levels, end-tidal concentrations of sevoflurane, and perioperative differences in heart rate or mean arterial pressure changes did not differ between the 2 groups. No differences were noted in perioperative QTc changes over time between the 2 groups, regardless of the calculation methods (Bazett, P = 0.87; Fridericia, P = 0.75; Hodges, P = 0.87). The perioperative QTcF or QTcH intervals were increased at all time points compared wi...

Haemostatic management of cardiac surgical haemorrhage

“…Aprotinin is a bovine-derived serine protease inhibitor which has powerful antiplasmin and antikallikrein effects. In high doses, it reduces bleeding in cardiac surgery [57]. It has a number of additional effects such as reduction in neutrophil activation and interaction with the renin-angiotensin system.…”

“…They have a plasma half-life of around 2 h, and are excreted in the urine in high concentrations [53]. The optimum dose of TXA is unknown despite its widespread international use, with 10 mg.kg À1 bolus followed by 1 mg.kg À1 .h À1 as a continuous infusion being the most commonly used regimen, with little evidence for higher doses [57]. Seizures are the main reported adverse event with TXA, but thrombotic events after its use have not been reported.…”

“…Where aprotinin is administered, care must be taken to assess the effect on celite-based coagulation tests such as some activated clotting test cartridges and aPTT reagents, and additional heparin administration may be required. The prolonged aPTT seen postoperatively, given the half-life of 10 h, may lead to inappropriate FFP or protamine administration [57].…”

“…Both agents have been shown to reduce blood loss, when used prophylactically in cardiac surgery. Tranexamic acid may be slightly more effective than EACA in reducing blood loss, however there is little evidence to support the exceedingly high doses (up to 10 g) used in some centres [57]. Aprotinin is a bovine-derived serine protease inhibitor which has powerful antiplasmin and antikallikrein effects.…”

Effect of prophylactic tranexamic acid on blood conservation in Indian women undergoing abdominal hysterectomy

“…26 There has been consistent results about the significant role of TXA in blood conservation in various settings, from trauma to cardiac, neurological, orthopedic, craniofacial, obstetric and gynaecological surgery. [6][7][8]27 Ker et al in their systematic review of randomized clinical trials on the effect of TXA on surgical blood loss had revealed that TXA reduces the probability of blood transfusion by 38%. 16 With growing evidence about the positive effects of TXA on perioperative bleeding and transfusion rate, this randomized, double-blinded, placebo-controlled study was conducted with the objective of determining whether a single prophylactic dose of TXA given intravenously can reduce perioperative blood loss and also the need for blood transfusion in patients undergoing abdominal hysterectomy.…”