Cerebral Perfusion Pressure Management in Head Injury

A method of ICP management is presented based upon maintenance of cerebral perfusion pressure (CPP = SABP − ICP) at 70–80 mm Hg or in some cases greater. To do this, we have employed volume expansion, nursed patients in the flat position, and actively used catecholamine infusions to maintain the SABP side of the CPP equation at levels necessary to obtain the target CPP. CSF drainage and mannitol have freely been used to maintain the ICP portion of the equation. Thirty-four consecutive patients with GCS ≤ 7 were admitted to the Neurosurgical Intensive Care Unit (GCS = 5.1 ± 1.4) and managed with this protocol. CPP was maintained at 84 ± 11 mm Hg, ICP was 23 ± 9.8 mm Hg, and SABP averaged 106 ± 11 mm Hg. CVP was 8.0 ± 3.7 mm Hg and average fluid intake was approximately 5.4 ± 3.9 liters/d. Output averaged 5.0 ± 4.0 liters/d; additionally, albumin (25%) (33 ± 44 gm/d) and PRBC's were used for vascular expansion and hemoglobin was maintained (11.5 ± 1.4 gm/dl). Three patients died of uncontrolled ICP (all protocol errors). Four other patients succumbed, none secondary to ICP and all secondary to potentially avoidable complications. Morbidity (GOS = 4.2 ± 0.87) appeared to be as good or superior to previous methods of therapy. Overall, mortality was 21% and that from uncontrollable ICP was 8%. This approach to the management of intracranial hypertension proved safe, rational, and greatly enhanced the therapeutic options available. It was also consistent with optimal care of other organ systems. The results bring into question many of the standard tenets of neurosurgical ICP management and suggest new avenues of investigation.