The urgent postoperative CT scan: a critical appraisal of its impact

Urgent CT scanning of critically ill neurosurgical patients is costly, labo ur intensive and associated with some risk. A study of urgent postoperative CT scans was carried out to assess the proportion that changed patient man agement. A further study evaluated the accuracy of predicting a haematoma. A retrospective analysis was carried out over a 6-month period of all scans performed within 48 h of craniotomy. This was followed by a prospective co mparison between the surgeon's estimate of the chance of a haematoma on the scan and the scan result. Of 184 patient undergoing craniotomy, 40 patient s (22%) were scanned within 48 h. Five patients were re-operated for haemat oma formation. Prospective assessment showed that surgeons consistently ove r-estimated the risk at haematoma (mean prescan estimate 69%, actual risk 8 %, p = 2.5 x 10(-12)). Less than 1 in 10 postoperative scans show a neurosu rgical target. Other changes in management following scanning were slight.