DOCUMENTED REVERSAL OF GLOBAL-ISCHEMIA IMMEDIATELY AFTER REMOVAL OF AN ACUTE SUBDURAL-HEMATOMA - REPORT OF 2 CASES

The authors report two cases of severe head injury with acute subdural hematoma, in which cerebral blood flow (CBF) and cerebral blood volum e (CBV) measurements were obtained prior to evacuation of the subdural hematoma and again immediately after removal. The first patient, a 21 -year-old man with a motor response localizing to pain, had a global C BF of 18.2 ml/100 gm/min and a decreased global CBV of 3.7 ml/100 gm a t 2.3 hours after injury. Immediately after removal of the subdural he matoma (8.1 hours after injury), CBF and CBV measurements revealed inc reases to 35.5 ml/100 gm/min and 5.8 ml/100 gm, respectively. The seco nd patient, a 49-year-old woman with a normal flexor motor response to pain, had preoperative global values of 15.8 ml/100 gm/min for CBF an d 2.0 ml/100 gm for CBV at 3 hours after injury. Postoperatively (9.3 hours after injury), the CBF and CBV values increased to 41.6 ml/100 g m/min and 4.0 ml/100 gm, respectively. The first patient, with only bo rderline ischemia and removal of the subdural hematoma within 3 hours, made a good recovery, while the second patient, with prolonged lower levels of CBF, remained in a persistent vegetative state. The low valu es of preoperative CBV argue for compression of the microcirculation a s the cause of ischemia.