Cerebral perfusion pressure below 60 mm Hg is common in the intraoperative setting

Abstract

Background: Maintaining adequate cerebral perfusion pressure (CPP) is of clinical concern in patients with neurological injury. Although there are extensive data on CPP in the ICU setting, there has been little quantitative study of CPP in the intraoperative setting.

Methods: We retrospectively analyzed the electronic intraoperative records of neurosurgical and trauma patients with concurrent intracranial and arterial pressure monitoring devices in continuous use for ≥45 minutes to calculate CPP (=mean arterial pressure-intracranial pressure). We assessed the total minutes and frequency of 5-minute epochs, during which the median CPP was <60 mm Hg, and the associated risk factors.

Results: A total of 155 trauma and neurosurgical patients were studied. In the neurosurgery cohort (n=88), 74% had at least one 5-minute epoch during which the median CPP was <60 mm Hg and the median total minutes of CPP<60 mm Hg was 39 [interquartile range (67), length of surgery 274 (300) min]. In the trauma cohort (n=67), 82% had at least one 5-minute epoch of <60 mm Hg, and the median total minutes CPP of <60 mm Hg was 35 [(59), length of surgery 159 (160) min]. For the entire cohort (n=155), patients with CPP<60 mm Hg were found to have higher intracranial pressure compared with patients with CPP≥60 mm Hg (P<0.001). Unlike the neurosurgical cohort, trauma patients with CPP<60 mm Hg had a greater frequency of episodes of mean arterial pressure <70 mm Hg (P=0.001).

Conclusions: CPP<60 mm Hg is common in the intraoperative setting of a tertiary medical center in 2 different surgical populations with intracranial pathology. Prospective studies of intraoperative CPP and neurological outcomes are warranted.