Brain hypoxia can occur after non-traumatic subarachnoid hemorrhage (SAH), even when levels of intracranial pressure (ICP) remain normal. Brain tissue oxygenation (PbtO2) can be measured as a part of a neurological multimodal neuromonitoring. Low PbtO2 has been associated with poor neurologic recovery. There is scarce data on the impact of PbtO2 guided-therapy on patients’ outcome. This single-center cohort study (June 2014–March 2020) included all patients admitted to the ICU after SAH who required multimodal monitoring. Patients with imminent brain death were excluded. Our primary goal was to assess the impact of PbtO2-guided therapy on neurological outcome. Secondary outcome included the association of brain hypoxia with outcome. Of the 163 patients that underwent ICP monitoring, 62 were monitored with PbtO2 and 54 (87%) had at least one episode of brain hypoxia. In patients that required treatment based on neuromonitoring strategies, PbtO2-guided therapy (OR 0.33 [CI 95% 0.12–0.89]) compared to ICP-guided therapy had a protective effect on neurological outcome at 6 months. In this cohort of SAH patients, PbtO2-guided therapy might be associated with improved long-term neurological outcome, only when compared to ICP-guided therapy.

BackgroundIntracranial multimodality monitoring (iMMM) is increasingly used in acute brain injured patients; however, safety and reliability remain major concerns to its routine implementation. MethodsWe performed a retrospective study including all patients undergoing iMMM at a single European center between July 2016 and January 2020. Brain tissue oxygenation probe (PbtO 2 ), alone or in combination with a microdialysis catheter and/or an 8-contact depth EEG electrode, was inserted using a triple lumen bolt system and targeting normal-appearing at risk brain area on the injured side, whenever possible. Surgical complications, adverse events and technical malfunctions, directly associated with iMMM were collected. A blinded imaging review was performed by an independent radiologist. Results113 patients with 123 iMMM insertions were included for a median monitoring time of 9 [3-14] days. Of those, 93 (76%) patients had only PbtO 2 probe insertion and 30 (24%) had also microdialysis and/or iEEG monitoring. SAH was the most frequent indication for iMMM (n = 60, 53%). At least one complication was observed in 67/123 (54%) iMMM placement, corresponding to 58/113 (51%) patients. Misplacement was observed in 16/123 (13%), resulting in a total of 6/16 (38%) malfunctioning PbtO 2 catheters. Intracranial hemorrhage was observed in 14 iMMM placements (11%), of which one required surgical drainage. Five placements were complicated by pneumocephalus and 4 with bone fragments, none of these requiring additional surgery. No CNS infection related to iMMM was observed. Seven (6%) probes were accidentally dislodged and 2 probes (2%) were accidentally broken. Ten PbtO 2 probes (8%) presented a technical malfunction after a median of 9 [ranges: 2-24] days after initiation of monitoring and 4 of them were replaced. ConclusionsIn this study, a high occurrence of complications related to iMMM was observed, although most of them did not require speci c interventions and did not result in malfunctioning monitoring.

Background Brain hypoxia can occur after spontaneous subarachnoid hemorrhage (SAH), even when levels of intracranial pressure (ICP) remain normal. Brain tissue oxygenation (PbtO2) can be measured as a part of a neurological multimodal neuromonitoring Low PbtO2 has been associated with poor neurologic recovery. There is scarce data on the impact of PbtO2 guided-therapy on patients’ outcome. Methods This single-center cohort study (June 2014-March 2020) included all patients admitted to the ICU after SAH who required multimodal monitoring. Patients with imminent brain death were excluded. Our primary goal was to assess the impact of PbtO2-guided therapy on neurological outcome. Secondary outcome included the association of brain hypoxia with outcome. Results Of the 163 patients that underwent ICP monitoring, 62 were monitored with PbtO2 and 54 (87%) had at least one episode of brain hypoxia. In patients that required treatment based on neuromonitoring strategies, PbtO2-guided therapy (OR 0.33 [CI 95% 0.12–0.90]) compared to ICP-guided therapy had a protective effect on neurological outcome at 6 months. Brain hypoxia was associated with unfavorable neurological (OR 4.51 [95% CI 1.17–17.45]). Conclusions In this cohort of SAH patients, PbtO2-guided therapy when compared to ICP guided therapy may be associated with improved long-term neurological outcome.

Traumatic brain injury (TBI) is a major public health burden, causing death and disability worldwide. Intracranial hypertension and brain hypoxia are the main mechanisms of secondary brain injury. As such, management strategies guided by intracranial pressure (ICP) and brain oxygen (PbtO 2 ) monitoring could improve the prognosis of these patients. Our objective was to summarize the current evidence regarding the impact of PbtO 2 -guided therapy on the outcome of patients with TBI. We performed a systematic search of PubMed, Scopus, and the Cochrane library databases, following the protocol registered in PROSPERO. Only studies comparing PbtO 2 /ICP-guided therapy with ICP-guided therapy were selected. Primary outcome was neurological outcome at 3 and 6 months assessed by using the Glasgow Outcome Scale; secondary outcomes included hospital and long-term mortality, burden of intracranial hypertension, and brain tissue hypoxia. Out of 6254 retrieved studies, 15 studies (n = 37,245 patients, of who 2184 received PbtO 2 -guided therapy) were included in the final analysis. When compared with ICP-guided therapy, the use of combined PbO 2 /ICP-guided therapy was associated with a higher probability of favorable neurological outcome (odds ratio 2.21 [95% confidence interval 1.72-2.84]) and of hospital survival (odds ratio 1.15 [95% confidence interval 1.04-1.28]). The heterogeneity (I 2 ) of the studies in each analysis was below 40%. However, the quality of evidence was overall low to moderate. In this meta-analysis, PbtO 2 -guided therapy was associated with reduced mortality and more favorable neurological outcome in patients with TBI. The low-quality evidence underlines the need for the results from ongoing phase III randomized trials.