Placement of intracranial pressure monitors: Are "normal" coagulation parameters necessary?

Introduction: Patients with head injuries frequently have abnormal coagulation studies. Monitoring intracranial pressure ICP) in head injured patients is common practice, but no best practice guidelines exist for coagulation parameters for ICP monitor placement. Purpose: To test the hypothesis that hemorrhagic complication rates from ICP monitor placement are low and that the use of FFP to correct coagulation parameters to "normal" is not indicated. Methods: Retrospective review of all patients admitted to a Level I trauma center over a 3 year period, who underwent fiberoptic intraparenchymal ICP monitoring was undertaken. Inclusion criteria were coagulation studies (prothrombin time (PT), partial thromboplastin time (PTT), international normalized ratio (INR), platelet count) before ICP monitor placement and head CT scans to assess for hemorrhage before and after monitor placement. Data collected included age, Glasgow coma score (GCS), head region abbreviated injury score (H_AIS), time to ICP monitor placement, complications and outcomes. Results: From 8/1/00 through 7/31/ 03, 5163 trauma patients were admitted, and 157 met inclusion criteria. Patients were stratified by INR, at the time of ICP placement as normal (0.8-1.2, 103 patients), borderline (1.3-1.6, 42 patients) and increased ( greater than or equal to1.7, 12 patients). There was no difference between the groups in age, gender or H_AIS. Twenty two patients had component therapy to correct coagulopathy before ICP insertion, but 10 had INRs in the borderline group and 12 remained with INRs greater than or equal to1.7. Eleven patients had platelet counts 50,000-100,000 at ICP monitor placement, despite platelet transfusions. Time from admission to ICP monitor placement was significantly longer in patients who received component therapy (19.2 +/- 19.7 hours versus 8.8 +/- 13.9 hours, p < 0.002). Three patients had clinically insignificant, petechial hemorrhages (1.9%); one in each group, with INRs of 1.2, 1.3, and 2.5, respectively. Conclusions: In patients with INR less than or equal to1.6, hemorrhagic complications after ICP monitor placement were infrequent. The use of FFP to "normalize" INR below this threshold is not supported by this data and delays monitor placement.