M. Ross Bullock
Damianos E. Sakas, M. Ross Bullock and Graham M. Teasdale
✓ Forty consecutive patients who underwent craniotomy for traumatic hematoma after developing bilateral fixed dilated pupils were studied to determine the factors influencing quality of survival and to seek criteria for management. Clinical and computerized tomography (CT) data were correlated with outcome 1 year after craniotomy. The functional recovery (good outcome or moderate disability) rate was 25%, with a mortality rate of 43%. Patients with subdural hematoma had a higher mortality rate (64%) compared to patients with extradural hematoma (18%) (chi-square test, p > 0.05). Other factors associated with markedly increased morbidity and mortality were increasing age (> 20 years), a prolonged interval (> 3 hours) between loss of pupillary reactivity and craniotomy, compression of basal cisterns, and presence of subarachnoid hemorrhage on CT. There were no survivors among patients exhibiting any of the following features: surgery 6 hours or more after bilateral loss of pupillary reactivity; age greater than 65 years; or absent motor response. Apart from the latter group, the nature of motor response (before pharmacological paralysis and intubation) was not a reliable predictor of mortality. The results suggest that the presence of an acute subdural hematoma is the single most important predictor of negative outcome in patients with bilateral unresponsive pupils.
Hyperbaric oxygen therapy
M. Ross Bullock
Ross Bullock, C. Oliver Hannemann, Lilian Murray and Graham M. Teasdale
✓ Of 850 patients who underwent craniotomy for evacuation of a traumatic intracranial mass, 59 (6.9%) developed a second hematoma at the operation site, which required a second operation. Compared to those who did not, patients who developed postcraniotomy hematoma (PCH) had a significantly higher incidence of evidence of alcohol intake and preoperative mannitol administration; a higher percentage had a bad outcome. Coagulopathy was frequent in PCH patients.
Although three-quarters of the initial hematomas were intradural, 69% of the PCH's were predominantly extradural. The large potential space underlying a craniotomy bone flap may predispose to development of a PCH. Intracranial pressure (ICP) was monitored in 39 of the 59 PCH patients, which allowed earlier detection of the PCH in 22 (56%). In 17 patients, the ICP failed to rise despite clinical deterioration, and detection of the PCH was delayed, significantly worsening the outcome in this group.
M. Ross Bullock
Christos M. Tolias, Michael Reinert, Rolf Seiler, Charlotte Gilman, Alexander Scharf and M. Ross Bullock
Object. The effect of normobaric hyperoxia (fraction of inspired O2 [FIO2] concentration 100%) in the treatment of patients with traumatic brain injury (TBI) remains controversial. The aim of this study was to investigate the effects of normobaric hyperoxia on five cerebral metabolic indices, which have putative prognostic significance following TBI in humans.
Methods. At two independent neurointensive care units, the authors performed a prospective study of 52 patients with severe TBI who were treated for 24 hours with 100% FIO2, starting within 6 hours of admission. Data for these patients were compared with data for a cohort of 112 patients who were treated in the past; patients in the historical control group matched the patients in our study according to their Glasgow Coma Scale scores after resuscitation and their intracranial pressure within the first 8 hours after admission. Patients were monitored with the aid of intracerebral microdialysis and tissue O2 probes.
Normobaric hyperoxia treatment resulted in a significant improvement in biochemical markers in the brain compared with the baseline measures for patients treated in our study (patients acting as their own controls) and also compared with findings from the historical control group. In the dialysate the glucose levels increased (369.02 ± 20.1 µmol/L in the control group and 466.9 ± 20.39 µmol/L in the 100% O2 group, p = 0.001), whereas the glutamate and lactate levels significantly decreased (p < 0.005). There were also reductions in the lactate/glucose and lactate/pyruvate ratios. Intracranial pressure in the treatment group was reduced significantly both during and after hyperoxia treatment compared with the control groups (15.03 ± 0.8 mm Hg in the control group and 12.13 ± 0.75 mm Hg in the 100% O2 group, p < 0.005) with no changes in cerebral perfusion pressure. Outcomes of the patients in the treatment group improved.
Conclusions. The results of the study support the hypothesis that normobaric hyperoxia in patients with severe TBI improves the indices of brain oxidative metabolism. Based on these data further mechanistic studies and a prospective randomized controlled trial are warranted.
Damianos E. Sakas, M. Ross Bullock, James Patterson, Donald Hadley, David J. Wyper and Graham M. Teasdale
✓ To assess the relationship between posttraumatic cerebral hyperemia and focal cerebral damage, the authors performed cerebral blood flow mapping studies by single-photon emission computerized tomography (SPECT) in 53 patients within 3 weeks of brain injury. Focal zones of hyperemia were present in 38% of patients. Hyperemia was correlated with clinical features and early computerized tomography (CT) and magnetic resonance (MR) imaging performed within 48 hours of the SPECT study and late CT and MR studies at 3 months. The hyperemia was observed primarily in structurally normal brain tissue (both gray and white matter), as revealed by CT and MR imaging, immediately adjacent to intraparenchymal or extracerebral focal lesions; it persisted for up to 10 days, but was never seen within the edematous pericontusional zones. The percentage of patients in the hyperemic group having brief (< 30 minutes) or no loss of consciousness was significantly higher than in the nonhyperemic group (twice as high, p < 0.05).
Other clinical parameters were not significantly more common in the hyperemic group. The mortality of patients with focal hyperemia was lower than that of individuals without it, and the outcome of survivors with hyperemia was slightly better than patients without hyperemia. These results differ from the literature, which suggests that global posttraumatic hyperemia is primarily an acute, malignant phenomenon associated with increased intracranial pressure, profound unconsciousness, and poor outcome. The current results agree with more recent studies which show that posttraumatic hyperemia may occur across a wide spectrum of head injury severity and may be associated with favorable outcome.