Portable head CT scan and its effect on intracranial pressure, cerebral perfusion pressure, and brain oxygen: Clinical article

Object. Follow-up head CT scans are important in neurocritical care but involve intrahospital transport that may be associated with potential hazards including a deleterious effect on brain tissue oxygen pressure (PbtO ₂). Portable head CT (pHCT) scans offer an alternative imaging technique without a need for patient transport. In this study, the investigators examined the effects of pHCT scans on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and PbtO₂ in patients with severe brain injury. Methods. Fifty-seven pHCT scans were obtained in 34 patients (mean age of 42 ± 15 years) who underwent continuous ICP, CPP, and PbtO₂ monitoring in the neuro intensive care unit at a university-based Level I trauma center. Patient ICU records were retrospectively reviewed and physiological data obtained during the 3 hours before and after pHCT scans were examined. Results. Before pHCT, the mean ICP and CPP were 14.3 ± 7.4 and 78.9 ± 20.2 mm Hg, respectively. Portable HCT had little effect on ICP (mean ICP 14.1 ± 6.6 mm Hg, p = 0.84) and CPP (mean CPP 81.0 ± 19.8 mm Hg, p = 0.59). The mean PbtO₂ was similar before and after pHCT (33.2 ± 17.0 mm Hg and 31.6 ± 15.9 mm Hg, respectively; p = 0.6). Ten episodes of brain hypoxia (PbtO₂ < 15 mm Hg) were observed before pHCT; these episodes prompted scans. Brain hypoxia persisted in 5 patients after pHCT despite treatment. No new episodes of brain hypoxia were observed during or after pHCT. Conclusions. These data suggest that pHCT scans do not have a detectable effect on a critically ill patient's ICP, CPP, or PbtO₂.