Management of intracerebral pressure in the neurosciences critical care unit

Impact of Skull Defects on the Role of CTA for Brain Death Confirmation

BACKGROUND AND PURPOSE

Intracranial pressure modifications caused by a skull defect, such as craniectomy or craniotomy, may change the hemodynamics and decrease the accuracy of CTA to confirm brain death. This study aimed to evaluate the impact of a skull defect and the interpretation criteria of images on this diagnostic test.

MATERIALS AND METHODS

A series of consecutive patients with a clinical diagnosis of brain death underwent CTA (case group), while the control group comprised patients with acute ischemic stroke in the same period. CTA criteria adopted to confirm brain death were the absence of opacification of the M4 branches and internal cerebral veins. The evaluation also included the presence of "stasis filling." Cases were stratified as intact skull, craniotomy, and craniectomy. Three neuroradiologists evaluated all examinations independently.

RESULTS

In the case group, according to the Frampas criteria, the sensitivity of CTA to confirm brain death was 95.5% in patients with intact skull, 87.5% with craniotomy, and 60% with craniectomy. False-negative diagnoses of brain death were 15.6%, related to stasis filling in 71.4% (P < .001). However, according to the "modified Frampas criteria," the sensitivity of CTA to confirm brain death was 100% in patients with intact skull, 93.8% with craniotomy, and 80% with craniectomy. False-negative diagnoses of brain death were found in 6.2% of patients, and there was no stasis filling. CTA showed 100% specificity in the control group. There were no disagreements among observers.

CONCLUSIONS

CTA had a high diagnostic accuracy and reproducibility to confirm brain death in patients with an intact skull. The modified Frampas criteria increased the sensitivity of CTA, particularly in patients with a skull defect. A concurrent skull defect, especially craniectomy, can decrease the sensitivity of CTA to confirm brain death.

Options for managing raised intracranial pressure

This article reviews the current monitoring and management options for raised intracranial pressure (ICP), primarily in traumatic head injuries, in line with current literature and guidelines. The use of ICP monitoring is useful in managing, predicting outcomes, following the progression and guiding interventions of neurological disease states.

Patients with raised ICP should be monitored closely in a neurocritical care setting where appropriate interventions can be instituted based on available monitoring parameters. Various first- and second-tier methods should be considered, with the primary goal to decrease secondary insult to brain tissue for best outcomes.

Clinical observation of the time course of raised intracranial pressure after subarachnoid hemorrhage

The time course of intracranial pressure (ICP) after subarachnoid hemorrhage (SAH) is not well known. This retrospective study was conducted to investigate the occurrence and the dynamic variation of raised ICP post-SAH. ICP was prospectively studied in 120 patients with SAH who were admitted to neurocritical care within 24 h of hemorrhage. Patients underwent continuous ICP monitoring for at least 7 days, unless they died. Clinical status on admission, radiographic tests, treatment details and neurological outcome on discharge were analyzed in relation to ICP. The highest daily mean ICP and the day when ICP reduced to normal levels were assessed. Of the 120 patients studied, 112 (93.3 %) encountered ICP elevation whilst in hospital. The daily mean ICP was higher in Hunt and Hess grades IV-V patients than grades I-III patients (P = 0.01). The elevated ICP remained at a higher level for the initial 3 days (grades I-III patients) or 4 days (grades IV-V patients), after which the pressure decreased towards normal levels. The in-patient mortality was significantly increased in the high ICP variability group (P = 0.001), which was divided by the cutoff point using receiver operating characteristic curve analysis. Raised ICP mainly occurs within 8 days post-SAH, especially the initial 3-4 days. Those highlight the need for earlier management of ICP after SAH.