Effect of regional cerebral oximetry to estimate neurologic prognostic outcomes in patients administered targeted temperature management

Neuromonitoring after Pediatric Cardiac Arrest: Cerebral Physiology and Injury Stratification

BACKGROUND

Significant long-term neurologic disability occurs in survivors of pediatric cardiac arrest, primarily due to hypoxic-ischemic brain injury. Postresuscitation care focuses on preventing secondary injury and the pathophysiologic cascade that leads to neuronal cell death. These injury processes include reperfusion injury, perturbations in cerebral blood flow, disturbed oxygen metabolism, impaired autoregulation, cerebral edema, and hyperthermia. Postresuscitation care also focuses on early injury stratification to allow clinicians to identify patients who could benefit from neuroprotective interventions in clinical trials and enable targeted therapeutics.

METHODS

In this review, we provide an overview of postcardiac arrest pathophysiology, explore the role of neuromonitoring in understanding postcardiac arrest cerebral physiology, and summarize the evidence supporting the use of neuromonitoring devices to guide pediatric postcardiac arrest care. We provide an in-depth review of the neuromonitoring modalities that measure cerebral perfusion, oxygenation, and function, as well as neuroimaging, serum biomarkers, and the implications of targeted temperature management.

RESULTS

For each modality, we provide an in-depth review of its impact on treatment, its ability to stratify hypoxic-ischemic brain injury severity, and its role in neuroprognostication.

CONCLUSION

Potential therapeutic targets and future directions are discussed, with the hope that multimodality monitoring can shift postarrest care from a one-size-fits-all model to an individualized model that uses cerebrovascular physiology to reduce secondary brain injury, increase accuracy of neuroprognostication, and improve outcomes.

Monitoring and modifying brain oxygenation in patients at risk of hypoxic ischaemic brain injury after cardiac arrest

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Regional cerebral oxygen saturation in cardiac arrest survivors undergoing targeted temperature management 36℃ versus 33℃: A randomized clinical trial

AIM

of study To investigate whether regional cerebral oxygen saturation (rSO₂) differs in out-of-hospital cardiac arrest (OHCA) survivors undergoing targeted temperature management (TTM) 36℃ versus 33℃.

METHODS

A randomized clinical trial was conducted at intensive care units in two referral hospitals. Fifty-seven comatose OHCA survivors were randomized into either a 36℃ or 33℃ group. Patients were cooled and maintained at an oesophageal temperature of either 36℃ or 33℃ for 24 hours, rewarmed at a rate of 0.25℃/hour, and maintained at < 37.5℃ until 72 hours. During 72 hours of TTM, rSO₂ was continuously monitored on the left forehead using near-infrared spectroscopy (INVOS^TM 5100C). The rSO₂ level at 72 hours was compared between the two groups. Next, serial rSO₂ levels for 72 hours were compared using mixed effects regression. The association between rSO₂ levels and 6-month neurological outcomes was also evaluated.

RESULTS

There were no significant differences in the rSO₂ level at 72 hours between the 36℃ and 33℃ groups (p = 0.372). Furthermore, serial rSO₂ levels for 72 hours of TTM were not different between the two groups (p = 0.733). However, low rSO₂ levels, particularly at 24 hours of TTM, were significantly associated with poor 6-month neurological outcomes (odds ratio = 0.899, 95% confidence interval: 0.831 - 0.974). The area under the receiver operating characteristic curve of the rSO₂ level at 24 hours for poor neurological outcomes was 0.800.

CONCLUSIONS

Regardless of target temperatures, low rSO₂ levels during TTM were significantly associated with poor 6-month neurological outcomes in OHCA survivors.

Near-Infrared Spectroscopy Assessments of Regional Cerebral Oxygen Saturation for the Prediction of Clinical Outcomes in Patients With Cardiac Arrest: A Review of Clinical Impact, Evolution, and Future Directions

Despite three decades of advancements in cardiopulmonary resuscitation (CPR) methods and post-resuscitation care, neurological prognosis remains poor among survivors of out-of-hospital cardiac arrest, and there are no reliable methods for predicting neurological outcomes in patients with cardiac arrest (CA). Adopting more effective methods of neurological monitoring may aid in improving neurological outcomes and optimizing therapeutic interventions for each patient. In the present review, we summarize the development, evolution, and potential application of near-infrared spectroscopy (NIRS) in adults with CA, highlighting the clinical relevance of NIRS brain monitoring as a predictive tool in both pre-hospital and in-hospital settings. Several clinical studies have reported an association between various NIRS oximetry measurements and CA outcomes, suggesting that NIRS monitoring can be integrated into standardized CPR protocols, which may improve outcomes among patients with CA. However, no studies have established acceptable regional cerebral oxygen saturation cut-off values for differentiating patient groups based on return of spontaneous circulation status and neurological outcomes. Furthermore, the point at which resuscitation efforts can be considered futile remains to be determined. Further large-scale randomized controlled trials are required to evaluate the impact of NIRS monitoring on survival and neurological recovery following CA.

Neurologic prognostication after resuscitation from cardiac arrest

Out-of-hospital cardiac arrest remains a leading cause of mortality in the United States, and the majority of patients who die after achieving return of spontaneous circulation die from withdrawal of care due to a perceived poor neurologic prognosis. Unfortunately, withdrawal of care often occurs during the first day of admission and research suggests this early withdrawal of care may be premature and result in unnecessary deaths for patients who would have made a full neurologic recovery. In this review, we explore the evidence for neurologic prognostication in the emergency department for patients who achieve return of spontaneous circulation after an out-of-hospital cardiac arrest.

Diagnostic Utility of N-terminal pro-Brain Natriuretic Peptide and C-reactive Protein in Diagnosing Heart Failure in Patients with Acute Hypoxemic Respiratory Failure

Introduction Shortness of breath is a leading cause of intensive care unit (ICU) admissions and is multifactorial. Acute hypoxemic respiratory failure due to heart failure is one of the leading causes of ICU admissions. N-terminal pro-brain natriuretic peptide (NT-proBNP) is secreted by ventricles and carries a negative predictive value for heart failure (2). NT-proBNP can also be raised in sepsis (4). Changes in NT-proBNP strongly correlated with changes in C-reactive protein (CRP) and leukocytes levels (8). Objective This study was conducted to explore the diagnostic utility of NT-proBNP and CRP to diagnose heart failure in patients presenting with acute hypoxemic respiratory failure. Materials and methods After informed consent and approval from the institutional review board (IRB), patients of acute hypoxemic respiratory failure were included in the study. History and physical examination were done by a medical resident and recorded in the patients' files. Data were transferred to a structured proforma by the researcher. All tests were conducted within three hours of presentation. The diagnosis of heart failure was made by a panel of experts, including the consultant cardiologist and consultant intensivist in charge. The chest X-ray was reported by the radiologist. The cost of the test was afforded by the institution. Data were analyzed by SPSS version 15 (SPSS Inc., Chicago, Illinois). Analysis of variance (ANOVA), Pearson correlation and linear regression were applied to find out the relation between variables and significance. Results We studied 137 patients. Out of them, 72.9% were diagnosed as heart failure. Heart failure was more common in females (43.7%) as compared to males (29%). NT-proBNP was raised in 111 (81%) patients and out of them, 88 patients (79%) had heart failure. Sensitivity and specificity of NT-proBNP were found to be (95.56%) and (46.81%), respectively. Similarly, CRP was 90% sensitive and 25.53% specific for heart failure. The most common findings in chest X-rays of patients with heart failure were upper lobe diversion and enlarged cardiothoracic ratio (71%). Conclusion We concluded our study as NT-proBNP is a highly sensitive test to diagnose heart failure in settings of acute hypoxemic respiratory failure. CRP is also significantly raised in heart failure. Upper lobe diversion and an increased cardiothoracic ratio is a strong predictor of heart failure.

The current significance of the FOUR score: A systematic review and critical analysis of the literature

BACKGROUND

The Full Outline of Un-Responsiveness Score (FOURs) is a scale for clinical assessment of consciousness that was introduced to overcome disadvantages of the widely accepted Glasgow Coma Scale (GCS).

OBJECTIVE

To carry out a systematic review and critical analysis of the available literature on the clinical application of FOURs and perform a comparison to GCS, in terms of reliability and predictive value.

METHODS

Initial search retrieved a total of 147 papers. After applying strict inclusion criteria and further article selection to overcome data heterogeneity, a statistical comparison of inter-rater reliability, in-hospital mortality and long-term outcome prediction between the two scales in the adult and pediatric population was done.

RESULTS

Even though FOURs is more complicated than GCS, its application remains quite simple. Its reliability, validity and predictive value have been supported by an increasing number of studies, especially in critical care. A statistically significant difference (p = .034) in predicting in-hospital mortality in adults, in favor of FOURs when compared to GCS, was found. However, whether it poses a clinically significant advantage in detecting patients' deterioration and outcome prediction, compared to other scaling systems, remains unclear.

CONCLUSIONS

Further studies are needed to discern the FOURs' clinical usefulness, especially in patients in non-critical condition, with milder disorders of consciousness.