Risk factors associated with bleeding during and after percutaneous dilational tracheostomy.

We evaluated the effect of pre-operative coagulation status on the incidence of acute and chronic bleeding in 415 consecutive patients undergoing percutaneous dilational tracheostomy. The incidence of acute bleeding was independent of the coagulation variables tested. The risk of chronic bleeding was higher with an activated partial thromboplastin time above 50 s (OR 3.7 (95% CI 1.1-12.7); NNT 18.4 (95% CI 9.0-infinity); p = 0.04), a platelet count below 50 x 10(9) l(-1) (OR 5.0 (95% CI 1.4-17.2); NNT 12.3 (95% CI 6.2-833.3); p = 0.01) and in the presence of two or more abnormal coagulation variables (OR 9.5 (95% CI 2.3-34.7); NNT 6.2 (95% CI 3.2-68); p = 0.002). Low-dose heparin treatment did not significantly increase the risk of chronic bleeding.