Cerebral multimodality monitoring in adult neurocritical care patients with acute brain injury: A narrative review

Abstract

Cerebral multimodality monitoring (MMM) is, even with a general lack of Class I evidence, increasingly recognized as a tool to support clinical decision-making in the neuroscience intensive care unit (NICU). However, literature and guidelines have focused on unimodal signals in a specific form of acute brain injury. Integrating unimodal signals in multiple signal monitoring is the next step for clinical studies and patient care. As such, we aimed to investigate the recent application of MMM in studies of adult patients with traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), acute ischemic stroke (AIS), and hypoxic ischemic brain injury following cardiac arrest (HIBI). We identified continuous or daily updated monitoring modalities and summarized the monitoring setting, study setting, and clinical characteristics. In addition, we discussed clinical outcome in intervention studies. We identified 112 MMM studies, including 11 modalities, over the last 7 years (2015–2022). Fifty-eight studies (52%) applied only two modalities. Most frequently combined were ICP monitoring (92 studies (82%)) together with PbtO2 (63 studies (56%). Most studies included patients with TBI (59 studies) or SAH (53 studies). The enrollment period of 34 studies (30%) took more than 5 years, whereas the median sample size was only 36 patients (q1- q3, 20–74). We classified studies as either observational (68 studies) or interventional (44 studies). The interventions were subclassified as systemic (24 studies), cerebral (10 studies), and interventions guided by MMM (11 studies). We identified 20 different systemic or cerebral interventions. Nine (9/11, 82%) of the MMM-guided studies included clinical outcome as an endpoint. In 78% (7/9) of these MMM-guided intervention studies, a significant improvement in outcome was demonstrated in favor of interventions guided by MMM. Clinical outcome may be improved with interventions guided by MMM. This strengthens the belief in this application, but further interdisciplinary collaborations are needed to overcome the heterogeneity, as illustrated in the present review. Future research should focus on increasing sample sizes, improved data collection, refining definitions of secondary injuries, and standardized interventions. Only then can we proceed with complex outcome studies with MMM-guided treatment.

Acute respiratory distress syndrome complicating traumatic brain injury. Can opposite strategies converge?

“…If the TBI patient has no ARDS, physicians should follow the Seattle consensus [13], apply the different tiers for ICP treatment, and consider the basic respiratory targets and settings recommended by current guidelines [10], with TV 6-8 ml of predicted body weight, PEEP 5 cmH 2 O, Pplat < 30 cmH 2 O and respiratory rate of 16-22 breaths/minute. On the other hand, in patients with ARDS and TBI without intracranial hypertension and with stable ICP despite lung protective ventilation settings, the latter should be continued while strictly monitoring cerebrovascular function preferably using a multimodal neuromonitoring approach [15].…”

Multimodal and autoregulation monitoring in the neurointensive care unit

“…ICP monitoring was first described by Lundberg and colleagues in 1964 and has since become the most widely employed invasive monitoring technique with the largest amount of supporting data (4,63). Elevations in ICP are directly related to excess mortality and poor neurologic outcomes, likely through destructive mechanical forces as well as reduced cerebral perfusion leading to ischemia and oligemia within vulnerable brain parenchyma (32,(64)(65)(66).…”

“…As such, there has been an increased focus over the past few decades on the development and utilization of neuromonitoring techniques that allow for enhanced surveillance of cerebral physiologic parameters in order to detect early signs of secondary brain injury and allow for goal directed interventions to stave off irreversible damage (3). Though advances in neuromonitoring represent a major breakthrough in the field of neurocritical care and provide new insights in the complexity of ABI pathophysiology, a single neuromonitoring device is insufficient in providing a comprehensive scope of the intricate and dynamic nature of impaired cerebral physiology (4,5). Subsequently focus has shifted to bundling complementary neuromonitoring techniques, termed multimodality monitoring (MMM), to enhance the predictive value of the physiologic outputs and allow for individualized patient management decisions (4,6).…”

“…Though advances in neuromonitoring represent a major breakthrough in the field of neurocritical care and provide new insights in the complexity of ABI pathophysiology, a single neuromonitoring device is insufficient in providing a comprehensive scope of the intricate and dynamic nature of impaired cerebral physiology ( 4 , 5 ). Subsequently focus has shifted to bundling complementary neuromonitoring techniques, termed multimodality monitoring (MMM), to enhance the predictive value of the physiologic outputs and allow for individualized patient management decisions ( 4 , 6 ).…”

“…Though advances in neuromonitoring represent a major breakthrough in the field of neurocritical care and provide new insights in the complexity of ABI pathophysiology, a single neuromonitoring device is insufficient in providing a comprehensive scope of the intricate and dynamic nature of impaired cerebral physiology ( 4 , 5 ). Subsequently focus has shifted to bundling complementary neuromonitoring techniques, termed multimodality monitoring (MMM), to enhance the predictive value of the physiologic outputs and allow for individualized patient management decisions ( 4 , 6 ). One of the advantages of the expanded use of MMM is the ability to characterize cerebral autoregulation (CA) capacity, which has been validated as an important prognostic indicator and may be useful to guide hemodynamic decisions, with the goal of optimizing cerebral perfusion ( 7 , 8 ).…”