Removal of all bone fragments is of greater importance than removal of all metal fragments. The use of intraoperative ultrasound facilitates localization of fragments. The debrided track should remain open after debridement. Closure of the track suggests the presence of deeper or adjacent clot or necrotic brain tissue exerting pressure on the track. Figure 29 E With high velocity injuries, there is more destruction at the wound of exit than the wound of entry, and debridement of the exit wound initially may provide the most rapid decompression.
Complete hemostasis is accomplished before closure.
Massive swelling of the brain is an uncommon but serious occurrence during operation that may represent the development of an intracerebral hematoma or a contralateral subdural hematoma. It may also represent an anesthetic complication or loss of autoregulation of the cerebral vasculature After determining that there is no technical difficulty with anesthesia, swelling is treated in a stepwise fashion by increasing the ventilatory rate to obtain a PaCO 2 of about 25mm Hg, by tapping the ventricle and draining CSF and by administering barbiturates. Pentobarbital sodium, 100-300 mg, is given intravenously. Additional doses of 100 mg may be required hourly. If the brain is swollen at the time of closure, an intracranial pressure monitoring catheter is placed, preferably intraventricularly, and the intracranial pressure is monitored in the post-operative period.