The effect of short-term antifibrinolytic therapy on experimental vasospasm

Pharmacological management of perioperative bleeding in cardiac surgery

[first paragraph of article]In spite of the growing discoveries in cardiac surgery, perioperative bleeding remains one of the most common causes of morbidity and mortality. Around 50-60% of cardiac surgery patients receive blood transfusions, which are harmful and strongly associated with increased morbidity, mortality, hospital stay, and hospital cost. Patients taken back to the OR for re-exploration and control of bleeding after cardiac surgery, have a four-fold increase in the incidence of sternal infection and mortality.

Intracisternal administration of tissue plasminogen activator improves cerebrospinal fluid flow and cortical perfusion after subarachnoid hemorrhage in mice

Early brain injury (EBI) during the first 72 h after subarachnoid hemorrhage (SAH) is an important determinant of clinical outcome. A hallmark of EBI, global cerebral ischemia, occurs within seconds of SAH and is thought to be related to increased intracranial pressure (ICP). We tested the hypothesis that ICP elevation and cortical hypoperfusion are the result of physical blockade of cerebrospinal fluid (CSF) flow pathways by cisternal microthrombi. In mice subjected to SAH, we measured cortical blood volume (CBV) using optical imaging, ICP using pressure transducers, and patency of CSF flow pathways using intracisternally injected tracer dye. We then assessed the effects of intracisternal injection of recombinant tissue plasminogen activator (tPA). ICP rose immediately after SAH and remained elevated for 24 h. This was accompanied by a decrease in CBV and impaired dye movement. Intracisternal administration of tPA immediately after SAH lowered ICP, increased CBV, and partially restored CSF flow at 24 h after SAH. Lowering ICP without tPA, by draining CSF, improved CBV at 1 h, but not 24 h after SAH. These findings suggest that blockade of CSF flow by microthrombi contributes to the early decline in cortical perfusion in an ICP-dependent and ICP-independent manner and that intracisternal tPA may reduce EBI and improve outcome after SAH.

The risks of aprotinin and tranexamic acid in cardiac surgery: a one-year follow-up of 1188 consecutive patients

BACKGROUND

Our aim was to investigate postoperative complications and mortality after administration of aprotinin compared to tranexamic acid in an unselected, consecutive cohort.

METHODS

Perioperative data from consecutive cardiac surgery patients were prospectively collected between September 2005 and June 2006 in a university-affiliated clinic (n = 1188). During the first 5 mo, 596 patients received aprotinin (Group A); in the next 5 mo, 592 patients were treated with tranexamic acid (Group T). Except for antifibrinolytic therapy, the anesthetic and surgical protocols remained unchanged.

RESULTS

The pre- and intraoperative variables were comparable between the treatment groups. Postoperatively, a significantly higher incidence of seizures was found in Group T (4.6% vs 1.2%, P < 0.001). This difference was also significant in the primary valve surgery and the high risk surgery subgroups (7.9% vs 1.2%, P = 0.003; 7.3% vs 2.4%, P = 0.035, respectively). Persistent atrial fibrillation (7.9% vs 2.3%, P = 0.020) and renal failure (9.7% vs 1.7%, P = 0.002) were also more common in Group T, in the primary valve surgery subgroup. On the contrary, among primary coronary artery bypass surgery patients, there were more acute myocardial infarctions and renal dysfunction in Group A (5.8% vs 2.0%, P = 0.027; 22.5% vs 15.2%, P = 0.036, respectively). The 1-yr mortality was significantly higher after aprotinin treatment in the high risk surgery group (17.7% vs 9.8%, P = 0.034).

CONCLUSION

Both antifibrinolytic drugs bear the risk of adverse outcome depending on the type of cardiac surgery. Administration of aprotinin should be avoided in coronary artery bypass graft and high risk patients, whereas administration of tranexamic acid is not recommended in valve surgery.