Intracranial pressure in patients undergoing decompressive craniectomy: new perspective on thresholds

Abstract

OBJECTIVE Decompressive craniectomy (DC) is an established part of treatment in patients suffering from malignant infarction of the middle cerebral artery (MCA) or traumatic brain injury (TBI). However, no clear evidence for intracranial pressure (ICP)-guided therapy after DC exists. The lack of this evidence might be due to the frequently used, but simplified threshold for ICP of 20 mm Hg, which determines further therapy. Therefore, the objective of this study was to evaluate this threshold's accuracy and to investigate the course of ICP values with respect to neurological outcome. METHODS Data on clinical characteristics and parameters of the ICP course on the intensive care unit were collected retrospectively in 102 patients who underwent DC between December 2007 and April 2014 at the authors' institution. The postoperative ICP course in the first 168 hours was recorded and analyzed. From these findings, ICP thresholds discriminating favorable from unfavorable outcome were calculated using conditional inference tree analysis. Additionally, survival analysis was performed using the Kaplan-Meier method. Prognostic factors were assessed via univariate analysis and multivariate logistic regression. Favorable outcome was defined as a score of 0-4 on the modified Rankin Scale. RESULTS Multivariate logistic regression revealed that anisocoria, diagnosis, and ICP values differed significantly between the outcome groups. ICP values in the favorable and unfavorable outcome groups differed significantly (p < 0.001), while the mean ICP of both groups lay below the limit of 20 mm Hg (17.5 and 11.5 mm Hg, respectively). These findings were reproduced when analyzing the underlying pathologies of TBI and MCA infarction separately. Based on these findings, optimized time-dependent threshold values were calculated and found to be between 10 and 17 mm Hg. These values significantly distinguished favorable from unfavorable outcome and predicted 30-day mortality (p < 0.001). CONCLUSIONS This study systematically evaluated ICP levels in a long-term analysis after DC and provides new, surprisingly low, time-dependent ICP thresholds for these patients. Future trials investigating the benefit of ICP-guided therapy should take these thresholds into consideration and validate them in further patient cohorts.

Intracranial pressure in patients with papilloedema

“…5 The low NPV observed in our study reflects the fact that papilloedema was also observed at pressures lower than 10 mm Hg. This result concurs with recent evidence, in which ICP threshold values between 10 and 17 mm Hg differentiated between favourable and unfavourable outcomes patients undergoing decompressive craniectomy.…”

“…This result concurs with recent evidence, in which ICP threshold values between 10 and 17 mm Hg differentiated between favourable and unfavourable outcomes patients undergoing decompressive craniectomy. 5 The low NPV observed in our study reflects the fact that papilloedema was also observed at pressures lower than 10 mm Hg.…”

The Effect of Controlled Decompression for Severe Traumatic Brain Injury: A Randomized, Controlled Trial

“…PTCI is one of the most severe secondary insults after TBI, and it has been presented as an indicator of poor clinical outcomes, with a high mortality rate despite appropriate medical and surgical interventions (8,(26)(27)(28). Some studies have reported that the overall mortality rate is as high as 50% (28,29).…”

“…We found that the incidence of post-operative cerebral infarction was higher in the rapid decompression group than in the controlled decompression group. Although many authors have reported that PTCI is rarely observed in TBI (27,29), it is very common in sTBI patients who undergo DC (8,25,28). Sauvigny et al (28) reported that 57 patients undergoing DC because of a space-occupying middle cerebral artery infarction developed PTCI.…”

Decompressive craniectomy, ICP monitoring and secondary necrosectomy as treatment options in patients presenting with malignant ischemic infarctions extending beyond the middle cerebral artery territory

“…The ICP monitoring was performed only in selected patients, and it is plausible that the knowledge of ICP dynamics could help identify patients requiring additional therapies. Further studies should clarify whether postoperative ICP monitoring and neurocritical care are justified in selected patients [5][6] and whether a more active management of patients with increased ICP following DC can positively influence outcome.…”