Near-infrared Spectroscopy Monitoring During Cardiac Arrest: A Systematic Review and Meta-analysis

Wolf Creek XVII Part 6: Physiology-Guided CPR

Introduction

Physiology-guided cardiopulmonary resuscitation (CPR) offers the potential to optimize resuscitation and enable early prognosis.

Methods

Physiology-Guided CPR was one of six focus topic for the Wolf Creek XVII Conference held on June 14-17, 2023 in Ann Arbor, Michigan, USA. International thought leaders and scientists in the field of cardiac arrest resuscitation from academia and industry were invited. Participants submitted via online survey knowledge gaps, barriers to translation and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category, which was then debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

Top knowledge gaps include identifying optimal strategies for the evaluation of physiology-guided CPR and the optimal values for existing patients using patient outcomes. The main barriers to translation are the limited usability outside of critical care environments and the training and equipment required for monitoring. The top research priorities are the development of clinically feasible and reliable methods to continuously and non-invasively monitor physiology during CPR and prospective human studies proving targeting parameters during CPR improves outcomes.

Conclusion

Physiology-guided CPR has the potential to provide individualized resuscitation and move away from a one-size-fits-all approach. Current understanding is limited, and clinical trials are lacking. Future developments need to consider the clinical application and applicability of measurement to all healthcare settings. Therefore, clinical trials using physiology-guided CPR for individualisation of resuscitation efforts are needed.

Integrating rSO2 and EEG monitoring in cardiopulmonary resuscitation: A novel methodology

Despite improvements in cardiopulmonary resuscitation (CPR), survival and neurologic recovery after cardiac arrest remain poor due to ischemia and subsequent reperfusion injury. As the likelihood of survival and favorable neurologic outcome decreases with increasing severity of ischemia during CPR, developing methods to measure the magnitude of ischemia during resuscitation is critical for improving overall outcomes. Cerebral oximetry, which measures regional cerebral oxygen saturation (rSO2) by near-infrared spectroscopy, has emerged as a potentially beneficial marker of cerebral ischemia during CPR. In numerous preclinical and clinical studies, higher rSO2 during CPR has been associated with improved cardiac arrest survival and neurologic outcome. There is also emerging evidence that this can be integrated with electroencephalogram (EEG) monitoring to provide a bimodal system of brain monitoring during CPR. In this method's review, we discuss the feasibility, application, and implications of this integrated monitoring approach, highlighting its significance for improving clinical outcomes in cardiac arrest management and guiding future research directions.

A new method of pulse control in cardiopulmonary resuscitation; Continuous femoral pulse check

OBJECTIVES

The reliability of manual pulse checks has been questioned but is still recommended in cardiopulmonary resuscitation (CPR) guidelines. The aim is to compare the 10-s carotid pulse check (CPC) between heart massage cycles with the continuous femoral pulse check (CoFe PuC) in CPR, and to propose a better location to shorten the interruption times for pulse check.

METHODS

A prospective study was conducted on 117 Non-traumatic CPR patients between January 2020 and January 2022. A total of 702 dependent pulse measurements were executed, where carotid and femoral pulses were simultaneously assessed. Cardiac ultrasound, end-tidal CO2, saturation, respiration, and blood pressure were employed for pulse validation.

RESULTS

The decision time for determining the presence of a pulse in the last cycle of CPR was 3.03 ± 1.26 s for CoFe PuC, significantly shorter than the 10.31 ± 5.24 s for CPC. CoFe PuC predicted the absence of pulse with 74% sensitivity and 88% specificity, while CPC predicted the absence of pulse with 91% sensitivity and 61% specificity.

CONCLUSION

CoFe PuC provides much earlier and more effective information about the pulse than CPC. This shortens the interruption times in CPR. CoFe PuC should be recommended as a new and useful method in CPR guidelines.

Cerebral Oximetry During Pediatric In-Hospital Cardiac Arrest: A Multicenter Study of Survival and Neurologic Outcome

OBJECTIVES

To determine if near-infrared spectroscopy measuring cerebral regional oxygen saturation (crS o2 ) during cardiopulmonary resuscitation is associated with return of spontaneous circulation (ROSC) and survival to hospital discharge (SHD) in children.

DESIGN

Multicenter, observational study.

SETTING

Three hospitals in the pediatric Resuscitation Quality (pediRES-Q) collaborative from 2015 to 2022.

PATIENTS

Children younger than 18 years, gestational age 37 weeks old or older with in-hospital cardiac arrest (IHCA) receiving cardiopulmonary resuscitation greater than or equal to 1 minute and intra-arrest crS o2 monitoring.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was ROSC greater than or equal to 20 minutes without extracorporeal membrane oxygenation. Secondary outcomes included SHD and favorable neurologic outcome (FNO) (Pediatric Cerebral Performance Category 1-2 or no change from prearrest). Among 3212 IHCA events (index and nonindex), 123 met inclusion criteria in 93 patients. Median age was 0.3 years (0.1-1.4 yr) and 31% (38/123) of the cardiopulmonary resuscitation events occurred in patients with cyanotic heart disease. Median cardiopulmonary resuscitation duration was 8 minutes (3-28 min) and ROSC was achieved in 65% (80/123). For index events, SHD was achieved in 59% (54/91) and FNO in 41% (37/91). We determined the association of median intra-arrest crS o2 and percent of crS o2 values above a priori thresholds during the: 1) entire cardiopulmonary resuscitation event, 2) first 5 minutes, and 3) last 5 minutes with ROSC, SHD, and FNO. Higher crS o2 for the entire cardiopulmonary resuscitation event, first 5 minutes, and last 5 minutes were associated with higher likelihood of ROSC, SHD, and FNO. In multivariable analysis of the infant group (age < 1 yr), higher crS o2 was associated with ROSC (odds ratio [OR], 1.06; 95% CI, 1.03-1.10), SHD (OR, 1.04; 95% CI, 1.01-1.07), and FNO (OR, 1.05; 95% CI, 1.02-1.08) after adjusting for presence of cyanotic heart disease.

CONCLUSIONS

Higher crS o2 during pediatric IHCA was associated with increased rate of ROSC, SHD, and FNO. Intra-arrest crS o2 may have a role as a real-time, noninvasive predictor of ROSC.

The association of regional cerebral oximetry and neurologically intact survival in a porcine model of cardiac arrest

Background

The objective of this study was to determine if regional cerebral oximetry (rSO2) assessed during CPR would be predictive of survival with favorable neurological function in a prolonged model of porcine cardiac arrest. This study also examined the relative predictive value of rSO2 and end-tidal carbon dioxide (ETCO2), separately and together.

Methods

This study is a post-hoc analysis of data from a previously published study that compared conventional CPR (C-CPR) and automated head-up positioning CPR (AHUP-CPR). Following 10 min of untreated ventricular fibrillation, 14 pigs were treated with either C-CPR (C-CPR) or AHUP-CPR. rSO2, ETCO2, and other hemodynamic parameters were measured continuously. Pigs were defibrillated after 19 min of CPR. Neurological function was assessed 24 h later.

Results

There were 7 pigs in the neurologically intact group and 7 pigs in the poor outcomes group. Within 6 min of starting CPR, the mean difference in rSO2 by 95% confidence intervals between the groups became statistically significant (p < 0.05). The receiver operating curve for rSO2 to predict survival with favorable neurological function reached a maximal area under the curve value after 6 min of CPR (1.0). The correlation coefficient between rSO2 and ETCO2 during CPR increased towards 1.0 over time. The combined predictive value of both parameters was similar to either parameter alone.

Conclusion

Significantly higher rSO2 values were observed within less than 6 min after starting CPR in the pigs that survived versus those that died. rSO2 values were highly predictive of survival with favorable neurological function.

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.

Skeletal muscle oxygenation during cardiopulmonary resuscitation as a predictor of return of spontaneous circulation: a pilot study

BACKGROUND

Near-infrared spectroscopy (NIRS) provides regional tissue oxygenation (rSO2) even in pulseless states, such as out-of-hospital cardiac arrest (OHCA). Brain rSO2 seems to be important predictor of return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). Aim of our study was to explore feasibility for monitoring and detecting changes of skeletal muscle rSO2 during resuscitation.

METHODS

Skeletal muscle and brain rSO2 were measured by NIRS (SenSmart Model X-100, Nonin, USA) during CPR in adult patient with OHCA. Start (basal) rSO2, maximal during CPR (maximal) and difference between maximal-minimal rSO2 (delta-rSO2), were recorded. Patients were divided into ROSC and NO-ROSC group.

RESULTS

20 patients [age: 66.0ys (60.5-79.5), 65% male] with OHCA [50% witnessed, 70% BLS, time to ALS 13.5 min (11.0-19.0)] were finally analyzed. ROSC was confirmed in 5 (25%) patients. Basal and maximal skeletal muscle rSO2 were higher in ROSC compared to NO-ROSC group [49.0% (39.7-53.7) vs. 15.0% (12.0-25.2), P =  0.006; 76.0% (52.7-80.5) vs. 34.0% (18.0-49.5), P =  0.005, respectively]. There was non-linear cubic relationship between time of collapse and basal skeletal muscle rSO2 in witnessed OHCA and without BLS (F-ratio = 9.7713, P =  0.0261). There was correlation between maximal skeletal muscle and brain rSO2 (n = 18, rho: 0.578, P =   0.0121).

CONCLUSIONS

Recording of skeletal muscle rSO2 during CPR in patients with OHCA is feasible. Basal and maximal skeletal muscle rSO2 were higher in ROSC compared to NO-ROSC group. Clinical trial registration number ClinicalTrials.gov, NCT04058925, registered on: 16th August 2019. URL of trial registry record: https://www.

CLINICALTRIALS

gov/ct2/show/NCT04058925?titles=Tissue+Oxygenation+During+Cardiopulmonary+Resuscitation+as+a+Predictor+of+Return+of+Spontaneous+Circulation&draw=2&rank=1 .

Resuscitation Strategies for Maximizing Survival

There is no single resuscitation strategy that will uniformly improve cardiac arrest outcomes. Traditional vital signs cannot be relied on in cardiac arrest, and the use of continuous capnography, regional cerebral tissue oxygenation, and continuous arterial monitoring are options for use early defibrillation are critical elements of resuscitation. Cardio-cerebral perfusion may be improved with the use of active compression-decompression CPR, an impedance threshold device, and head-up CPR. In refractory shockable arrest, if ECPR is not an option, consider changing defibrillator pad placement and/or double defibrillation, additional medication options, and possibly stellate ganglion block.

Differences in Cerebral Oxygenation in Cardiogenic and Respiratory Cardiac Arrest Before, During, and After Cardiopulmonary Resuscitation

We compared the changes in cerebral oxygen saturation (ScO₂) levels during cardiac arrest (CA) events using porcine models of ventricular fibrillation CA (VF-CA) and asphyxial CA (A-CA). Twenty female pigs were randomly divided into VF-CA and A-CA groups. We initiated cardiopulmonary resuscitation (CPR) 4 min after CA and measured the cerebral tissue oxygenation index (TOI) using near-infrared spectroscopy (NIRS) before, during, and after CPR. In both groups, the TOI was the lowest at 3-4 min after pre-CPR phase initiation (VF-CA group: 3.4 min [2.8-3.9]; A-CA group: 3.2 min [2.9-4.6]; p = 0.386). The increase in TOI differed between the groups in the CPR phase (p < 0.001); it increased more rapidly in the VF-CA group (16.6 [5.5-32.6] vs. 1.1 [0.6-3.3] %/min; p < 0.001). Seven pigs surviving for 60 min after the return of spontaneous circulation in the VF-CA group recovered limb movement, whereas only one in the A-CA group (p = 0.023) achieved movement recovery. The increase in the TOI did not differ significantly between the groups in the post-CPR phase (p = 0.341). Therefore, it is better to monitor ScO₂ concomitantly with CPR initiation using NIRS to assess the responsiveness to CPR in clinical settings.

Evaluation of transcutaneous near-infrared spectroscopy for early detection of cardiac arrest in an animal model

Sudden cardiac arrest (SCA) is a leading cause of mortality worldwide. The SCA-to-resuscitation interval is a key determinant of patient outcomes, highlighting the clinical need for reliable and timely detection of SCA. Near-infrared spectroscopy (NIRS), a non-invasive optical technique, may have utility for this application. We investigated transcutaneous NIRS as a method to detect pentobarbital-induced changes during cardiac arrest in eight Yucatan miniature pigs. NIRS measurements during cardiac arrest were compared to invasively acquired carotid blood pressure and partial oxygen pressure (PO₂) of spinal cord tissues. We observed statistically significant decreases in mean arterial pressure (MAP) 64.68 mmHg ± 13.08, p < 0.0001), spinal cord PO₂ (38.16 mmHg ± 20.04, p = 0.0028), and NIRS-derived tissue oxygen saturation (TSI%) (14.50% ± 3.80, p < 0.0001) from baseline to 5 min after pentobarbital administration. Euthanasia-to-first change in hemodynamics for MAP and TSI (%) were similar [MAP (10.43 ± 4.73 s) vs TSI (%) (12.04 ± 1.85 s), p = 0.3714]. No significant difference was detected between NIRS and blood pressure-derived pulse rates during baseline periods (p > 0.99) and following pentobarbital administration (p = 0.97). Transcutaneous NIRS demonstrated the potential to identify rapid hemodynamic changes due to cardiac arrest in periods similar to invasive indices. We conclude that transcutaneous NIRS monitoring may present a novel, non-invasive approach for SCA detection, which warrants further investigation.

Prehospital technologies for early stroke detection - A review

The rate of neural circuitry loss in a typical large vessel occlusion well emphasizes that 'Time is Brain'. Every untreated minute in a large vessel ischaemic stroke results in loss of 1.9 million neurons and 13.8 billion synapses. As such, it is essential to optimize the flow-limiting steps in delivering the current standard of care. The current diagnostic model involves recognition of symptoms by patients, followed by access to Emergency Medical Services and subsequent physical examination and neuroimaging in the Emergency Department. With more than 50% of stroke patients using Emergency Medical Services as the first point of care contact, it can be deduced that the outcome of the 'stroke chain of survival' can be improved by addressing the bottleneck of prehospital stroke diagnosis. Here we present a review of the existing technologies.

Association between regional cerebral oxygen saturation and outcome of patients with out-of-hospital cardiac arrest: An observational study

Aim

This study aimed to evaluate the association between cerebral oxygen saturation (StO2) and return of spontaneous circulation (ROSC) in patients with out-of-hospital cardiac arrest (OHCA).

Methods

We retrospectively evaluated the data of patients with OHCA to determine the association between ROSC and various StO2 parameters (initial_StO2, final_StO2, mean_StO2, and Δ_StO2 [=final_StO2-initial_StO2]). Time-domain near-infrared spectroscopy was used to determine absolute StO2 values.

Results

Of the 108 patients with OHCA, 23 achieved ROSC. Although initial_StO2 values did not differ between the groups, final_StO2, mean_StO2, and Δ_StO2 were higher in the ROSC group than in the non-ROSC group. The cut-off values for initial_StO2, mean_StO2, and Δ_StO2 as predictors of ROSC were 35%, 30%, and 5%, respectively. The odds ratio for ROSC had markedly increased in the Δ_StO2 ≥ 5% subgroup (19.70 [6.06-64.11], p < 0.001). When the change in StO2 (=d_StO2) at 8 min from the initiation of StO2 measurement was assessed, the d_StO2 ≥ 5% subgroup had a higher odds ratio for ROSC than the d_StO2 < 5% subgroup (5.8 [1.78-18.85], p = 0.002), and this tendency was maintained until 20 min. In the evaluation using a two-by-two contingency table with initial_StO2 and Δ_StO2 as two parameters, 61.9% of the patients fell under the categories of initial_StO2 < 35% and Δ_StO2 < 5% and had the lowest rate of ROSC achievement (4.6%). In the Δ_StO2 ≥ 5% subgroup, approximately-two-thirds of the patients achieved ROSC irrespective of the initial_StO2 (initial_StO2 ≥ 35%, 66.7%; initial_StO2 < 35%, 60.0%).

Conclusions

Initial_StO2 and Δ_StO2 were associated with the achievement of ROSC.

Regional Cerebral Oxygen Saturation to Predict Favorable Outcome in Extracorporeal Cardiopulmonary Resuscitation: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review and meta-analysis aimed to investigate the role of regional cerebral oxygen saturation (rSO₂) in predicting survival and neurologic outcomes after extracorporeal cardiopulmonary resuscitation (ECPR).

DESIGN

The study authors performed a systematic review and meta-analysis of all available literature.

SETTING

The authors searched relevant databases (Pubmed, Medline, Embase) for studies measuring precannulation rSO₂ in patients undergoing ECPR and reporting mortality and/or neurologic outcomes.

PARTICIPANTS

The authors included both in-hospital and out-of-hospital cardiac arrest patients receiving ECPR. They identified 3 observational studies, including 245 adult patients.

INTERVENTIONS

The authors compared patients with a low precannulation rSO₂ (≤15% or 16%) versus patients with a high (>15% or 16%) precannulation rSO₂. In addition, the authors carried out subgroup analyses on out-of-hospital cardiac arrest (OHCA) patients.

MEASUREMENTS AND MAIN RESULTS

A high precannulation rSO₂ was associated with an overall reduced risk of mortality in ECPR recipients (98 out of 151 patients [64.9%] in the high rSO₂ group, v 87 out of 94 patients [92.5%] in the low rSO₂ group, risk differences [RD] -0.30; 95% CI -0.47 to -0.14), and in OHCA (78 out of 121 patients [64.5%] v 82 out of 89 patients [92.1%], RD 0.30; 95% CI -0.48 to -0.12). A high precannulation rSO₂ also was associated with a significantly better neurologic outcome in the overall population (42 out of 151 patients [27.8%] v 2 out of 94 patients [2.12%], RD 0.22; 95% CI 0.13-0.31), and in OHCA patients (33 out of 121 patients [27.3%] v 2 out of 89 patients [2.25%] RD 0.21; 95% CI 0.11-0.30).

CONCLUSIONS

A low rSO₂ before starting ECPR could be a predictor of mortality and survival with poor neurologic outcomes.

Prehospital monitoring of cerebral circulation during out of hospital cardiac arrest ? A feasibility study

BACKGROUND

About two-thirds of the in-hospital deaths after out-of-hospital cardiac arrests (OHCA) are a consequence of anoxic brain injuries, which are due to hypoperfusion of the brain during the cardiac arrests. Being able to monitor cerebral perfusion during cardiopulmonary resuscitation (CPR) is desirable to evaluate the effectiveness of the CPR and to guide further decision making and prognostication.

METHODS

Two different devices were used to measure regional cerebral oxygen saturation (rSO2): INVOS™ 5100 (Medtronic, Minneapolis, MN, USA) and Root® O3 (Masimo Corporation, Irvine, CA, USA). At the scene of the OHCA, advanced life support (ALS) was immediately initiated by the Emergency Medical Services (EMS) personnel. Sensors for measuring rSO2 were applied at the scene or during transportation to the hospital. rSO2 values were documented manually together with ETCO2 (end tidal carbon dioxide) on a worksheet specially designed for this study. The study worksheet also included a questionnaire for the EMS personnel with one statement on usability regarding potential interference with ALS.

RESULTS

Twenty-seven patients were included in the statistical analyses. In the INVOS™5100 group (n = 13), the mean rSO2 was 54% (95% CI 40.3-67.7) for patients achieving a return of spontaneous circulation (ROSC) and 28% (95% CI 12.3-43.7) for patients not achieving ROSC (p = 0.04). In the Root® O3 group (n = 14), the mean rSO2 was 50% (95% CI 46.5-53.5) and 41% (95% CI 36.3-45.7) (p = 0.02) for ROSC and no ROSC, respectively. ETCO2 values were not statistically different between the groups. The EMS personnel graded the statement of interference with ALS to a median of 2 (IQR 1-6) on a 10-point Numerical Rating Scale.

CONCLUSION

Our results suggest that both INVOS™5100 and ROOT® O3 can distinguish between ROSC and no ROSC in OHCA, and both could be used in the pre-hospital setting and during transport with minimal interference with ALS.

Low frequency power in cerebral blood flow is a biomarker of neurologic injury in the acute period after cardiac arrest

AIM

Cardiac arrest often results in severe neurologic injury. Improving care for these patients is difficult as few noninvasive biomarkers exist that allow physicians to monitor neurologic health. The amount of low-frequency power (LFP, 0.01-0.1 Hz) in cerebral haemodynamics has been used in functional magnetic resonance imaging as a marker of neuronal activity. Our hypothesis was that increased LFP in cerebral blood flow (CBF) would be correlated with improvements in invasive measures of neurologic health.

METHODS

We adapted the use of LFP for to monitoring of CBF with diffuse correlation spectroscopy. We asked whether LFP (or other optical biomarkers) correlated with invasive microdialysis biomarkers (lactate-pyruvate ratio - LPR - and glycerol concentration) of neuronal injury in the 4 h after return of spontaneous circulation in a swine model of paediatric cardiac arrest (Sus scrofa domestica, 8-11 kg, 51% female). Associations were tested using a mixed linear effects model.

RESULTS

We found that higher LFP was associated with higher LPR and higher glycerol concentration. No other biomarkers were associated with LPR; cerebral haemoglobin concentration, oxygen extraction fraction, and one EEG metric were associated with glycerol concentration.

CONCLUSION

Contrary to expectations, higher LFP in CBF was correlated with worse invasive biomarkers. Higher LFP may represent higher neurologic activity, or disruptions in neurovascular coupling. Either effect may be harmful in the acute period after cardiac arrest. Thus, these results suggest our methodology holds promise for development of new, clinically relevant biomarkers than can guide resuscitation and post-resuscitation care. Institutional protocol number: 19-001327.

Lawrence K, Tachtsidis I, Tong Y, Torricelli A, Urner T, Wabnitz H, Wolf M, Wolf U, Xu S, Yang C, Yodh AG, Yücel MA, Zhou W. Optical imaging and spectroscopy for the study of the human brain: status report

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions.

Accuracy of the Initial Rhythm to Predict a Short No-Flow Time in Out-of-Hospital Cardiac Arrest

OBJECTIVES

The no-flow time (NFT) can help establish prognosis in out-of-hospital cardiac arrest (OHCA) patients. It is often used as a selection criterion for extracorporeal resuscitation. In patients with an unwitnessed OHCA for whom the NFT is unknown, the initial rhythm has been proposed to identify those more likely to have had a short NFT. Our objective was to determine the predictive accuracy of an initial shockable rhythm for an NFT of 5 minutes or less (NFT ≤ 5).

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Prehospital OHCA in eight U.S. and three Canadian sites.

PATIENTS

A total of 28,139 adult patients with a witnessed nontraumatic OHCA were included, of whom 11,228 (39.9%) experienced an emergency medical service-witnessed OHCA (NFT = 0), 695 (2.7%) had a bystander-witnessed OHCA, and an NFT less than or equal to 5, and 16,216 (57.6%) with a bystander-witnessed OHCA and an NFT greater than 5.

INTERVENTIONS

Sensitivity, specificity, and likelihood ratios of an initial shockable rhythm to identify patients with an NFT less than or equal to 5 minutes.

MEASUREMENTS AND MAIN RESULTS

The sensitivity of an initial shockable rhythm to identify patients with an NFT less than or equal to 5 was poor (25% [95% CI, 25-26]), but specificity was moderate (70% [95% CI, 69-71]). The positive and likelihood ratios were inverted (negative accuracy) (positive likelihood ratio, 0.76 [95% CI, 0.74-0.79]; negative likelihood ratio, 1.12 [95% CI, 1.10-1.12]). Including only patients with a bystander-witnessed OHCA improved the sensitivity to 48% (95% CI, 45-52), the positive likelihood ratio to 1.45 (95% CI, 1.33-1.58), and the negative likelihood ratio to 0.77 (95% CI, 0.72-0.83), while slightly lowering the specificity to 67% (95% CI, 66-67).

CONCLUSIONS

Our analysis demonstrated that the presence of a shockable rhythm at the time of initial assessment was poorly sensitive and only moderately specific for OHCA patients with a short NFT. The initial rhythm, therefore, should not be used as a surrogate for NFT in clinical decision-making.

The Predictive Power of Near-Infrared Spectroscopy in Improving Cognitive Problems in Patients Undergoing Brain Surgeries: A Systematic Review

One of the main objectives in neurosurgical procedures is the prevention of cerebral ischemia and hypoxia leading to secondary brain injury. Different methods for early detection of intraoperative cerebral ischemia and hypoxia have been used. Near-infrared spectroscopy (NIRS) is a simple, non-invasive method for monitoring cerebral oxygenation increasingly used today. The aim of this study was to systematically review the brain monitoring with NIRS in neurosurgery. The search process resulted in the detection of 324 articles using valid keywords on the electronic databases, including Embase, PubMed, Scopus, Web of Science, and Cochrane Library. Subsequently, the full texts of 34 studies were reviewed, and finally 11 articles (seven prospective studies, three retrospective studies, and one randomized controlled trial) published from 2005 to 2020 were identified as eligible for systematic review. Meta-analysis was not possible due to high heterogeneity in neurological and neurosurgical conditions of patients, expression of different clinical outcomes, and different standard reference tests in the studies reviewed. The results showed that NIRS is a non-invasive cerebral oximetry that provides continuous and measurable cerebral oxygenation information and can be used in a variety of clinical settings.

Prediction of return of spontaneous circulation during cardiopulmonary resuscitation by pulse-wave cerebral tissue oxygen saturation: a retrospective observational study

Background

It is difficult to predict the return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). Cerebral tissue oxygen saturation during CPR, as measured by near-infrared spectroscopy (NIRS), is anticipated to predict ROSC. General markers of cerebral tissue oxygen saturation, such as the tissue oxygenation index (TOI), mainly reflect venous oxygenation, whereas pulse-wave cerebral tissue oxygen saturation (SnO₂), which represents hemoglobin oxygenation in the pulse wave within the cerebral tissue, is an index of arterial and venous oxygenation. Thus, SnO₂ may reflect arterial oxygenation to a greater degree than does TOI. Therefore, we conducted this study to verify our hypothesis that SnO₂ measured during CPR can predict ROSC.

Methods

Cardiac arrest patients who presented at the Emergency Department of Yamagata University Hospital in Japan were included in this retrospective, observational study. SnO₂ and TOI were simultaneously measured at the patient’s forehead using an NIRS tissue oxygenation monitor (NIRO 200-NX; Hamamatsu Photonics, Japan). We recorded the initial, mean, and maximum values during CPR. We plotted receiver operating characteristic curves and calculated the area under the curve (AUC) to predict ROSC.

Results

Forty-two patients were included. SnO₂ was significantly greater in the ROSC group than in the non-ROSC group in terms of the initial (37.5% vs 24.2%, p = 0.015), mean (44.6% vs 10.8%, p < 0.001), and maximum (79.7% vs 58.4%, p < 0.001) values. Although the initial TOI was not significantly different between the two groups, the mean (45.1% vs 36.8%, p = 0.018) and maximum (71.0% vs 46.3%, p = 0.001) TOIs were greater in the ROSC group than in the non-ROSC group. The AUC was 0.822 for the mean SnO₂ (95% confidence interval [CI]: 0.672–0.973; cut-off: 41.8%), 0.821 for the maximum SnO₂ (95% CI: 0.682–0.960; cut-off: 70.8%), and 0.809 for the maximum TOI (95% CI: 0.667–0.951; cut-off: 49.3%).

Conclusion

SnO₂ values measured during CPR, including immediately after arrival at the emergency department, were higher in the ROSC group than in the non-ROSC group.

The Effect of Intraoperative Cerebral Oximetry Monitoring on Postoperative Cognitive Dysfunction and ICU Stay in Adult Patients Undergoing Cardiac Surgery: An Updated Systematic Review and Meta-Analysis

Aim

Determining whether intraoperative cerebral oximetry monitoring-guided intervention reduces the risk of postoperative cognitive dysfunction remains controversial. The objective of this study was to conduct an up-to-date meta-analysis to comprehensively assess the effects of regional cerebral oxygen saturation (rSO₂) monitoring-guided intervention on cognitive outcomes after cardiac surgery.

Methods

PubMed, EMBASE, Ovid, and Cochrane Library databases were systematically searched using the related keywords for cardiac surgical randomized-controlled trials (RCTs) published from their inception to July 31, 2021. The primary outcome was postoperative delirium (POD). The secondary outcomes were postoperative cognitive decline (POCD) and other major postoperative outcomes. The odds ratio (OR) or weighted mean differences (WMDs) with 95% confidence interval (CI) were used to pool the data. The random-effect model was used for the potential clinical inconsistency. We performed meta-regression and subgroup analyses to assess the possible influence of rSO₂ monitoring-guided intervention on clinical outcomes.

Results

In total, 12 RCTs with 1,868 cardiac surgical patients were included. Compared with controls, the incidences of POD (n = 6 trials; OR, 0.28; 95% CI, 0.09–0.84; p = 0.02; I² = 81%) and POCD (n = 5 trials; OR, 0.38; 95% CI, 0.16–0.93; p = 0.03; I² = 78%) were significantly lower in the intervention group. Cerebral oximetry desaturation also showed a positive association with the incidence of POD (n = 5 trials; OR, 2.02; 95% CI, 1.25–3.24; p = 0.004; I² = 81%). The duration of intensive care unit (ICU) stay was markedly shorter in the intervention group than in the control group (n = 10 trials; WMD, −0.22 days; 95% CI, −0.44 to −0.00; p = 0.05; I² = 74%). Univariate meta-regression analyses showed that the major sources of heterogeneity were age (p = 0.03), body mass index (BMI, p = 0.05), and the proportion of congenital heart disease (CHD, p = 0.02) for POD, age (p = 0.04) for POCD, diabetes mellitus (DM, p = 0.07), cerebrovascular accident (CVA, p = 0.02), and chronic obstructive pulmonary disease (COPD, p = 0.09) for ICU stay. Subsequent subgroup analyses also confirmed these results.

Conclusion

Available evidence from the present study suggests that an intraoperative cerebral oximetry desaturation is associated with an increased POD risk, and the rSO₂ monitoring-guided intervention is correlated with a lower risk of POD and POCD, and a shorter ICU stay in adults undergoing cardiac surgery. These clinical benefits may be limited in patients with older age, diabetes status, high BMI, non-CHD, non-COPD, or a previous cardiovascular accident.

Systematic Review Registration: [PROSPREO], identifier: [CRD42021252654].

Early Changes in Near-Infrared Spectroscopy Are Associated With Cardiac Arrest in Children With Congenital Heart Disease

BACKGROUND

The association of near-infrared spectroscopy (NIRS) with various outcomes after pediatric cardiac surgery has been studied extensively. However, the role of NIRS in the prediction of cardiac arrest (CA) in children with heart disease has yet to be evaluated. We sought to determine if a model utilizing regional cerebral oximetry (rSO2c) and somatic oximetry (rSO2s) could predict CA in children admitted to a single-center pediatric cardiac intensive care unit (CICU).

METHODS

We retrospectively reviewed 160 index CA events for patients admitted to our pediatric CICU between November 2010 and January 2019. We selected 711 control patients who did not have a cardiac arrest. Hourly data was collected from the electronic health record (EHR). We previously created a machine-learning algorithm to predict the risk of CA using EHR data. Univariable analysis was done on these variables, which we then used to create a multivariable logistic regression model. The outputs from the model were presented by odds ratio (OR) and 95% confidence interval (CI).

RESULTS

We created a multivariable model to evaluate the association of CA using five variables: arterial saturation (SpO2)- rSO2c difference, SpO2-rSO2s difference, heart rate, diastolic blood pressure, and vasoactive inotrope score. While the SpO2-rSO2c difference was not a significant contributor to the multivariable model, the SpO2-rSO2s difference was. The average SpO2-rSO2s difference cutoff with the best prognostic accuracy for CA was 29% [CI 26-31%]. In the multivariable model, a 10% increase in the SpO2-rSO2s difference was independently associated with increased odds of CA [OR 1.40 (1.18, 1.67), P < 0.001] at 1 h before CA. Our model predicted CA with an AUROC of 0.83 at 1 h before CA.

CONCLUSION

In this single-center case-control study of children admitted to a pediatric CICU, we created a multivariable model utilizing hourly data from the EHR to predict CA. At 1 h before the event, for every 10% increase in the SpO2-rSO2s difference, the odds of cardiac arrest increased by 40%. These findings are important as the field explores ways to capitalize on the wealth of data at our disposal to improve patient care.

Real-Time Brain Monitoring by Near-Infrared Spectroscopy Predicts Neurological Outcome after Cardiac Arrest and Resuscitation in Rats: A Proof of Concept Study of a Novel Prognostic Measure after Cardiac Arrest

Clinical studies have demonstrated that dynamic changes in regional cerebral oxygen saturation (rSO₂) after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) have a role in predicting neurological outcomes after the return of spontaneous circulation (ROSC). Our study evaluated whether the timing of rSO₂ decline shortly after CPR reflects the severity of brain injury in a rat model of CA. Rats were subjected to different durations of asphyxia to produce variable severities of brain injury, due to CA. Time from ROSC to achieving the initial minimum rSO₂ was defined as T_nadir. A T_nadir cut-off of 24 min had optimal sensitivity and specificity for predicting good neurological outcomes at 72 h after ROSC (AUC, 0.88; sensitivity, 89%; specificity, 86%; p < 0.01). Immunohistochemistry at 72 h post-CA revealed that the number of Fluoro-Jade B positive degenerating neurons in the hippocampus CA1 sector were markedly higher in animals with T_nadir > 24 min than that in animals with T_nadir ≤ 24 min. There was no difference in the gene expressions of cytokines and mitochondrial fission proteins in the brain at 2 h after ROSC between rats with T_nadir > 24 min and with T_nadir ≤ 24 min. In conclusion, T_nadir can be a novel predictor of good neurological outcomes after CA/CPR.

Cerebral oximetry: a developing tool for monitoring cerebral oxygenation during cardiopulmonary resuscitation

Despite improvements in cardiopulmonary resuscitation (CPR), survival and neurologic recovery after cardiac arrest remain very poor because of the impact of severe ischemia and subsequent reperfusion injury. As the likelihood of survival and favorable neurologic outcome decreases with increasing severity of ischemia during CPR, developing methods to measure the magnitude of ischemia during resuscitation, particularly cerebral ischemia, is critical for improving overall outcomes. Cerebral oximetry, which measures regional cerebral oxygen saturation (rSO₂ ) by near-infrared spectroscopy, has emerged as a potentially beneficial marker of cerebral ischemia during CPR. In numerous preclinical and clinical studies, higher rSO₂ during CPR has been associated with improved cardiac arrest survival and neurologic outcome. In this narrative review, we summarize the scientific rationale and validation of cerebral oximetry across populations and pathophysiologic states, discuss the evidence surrounding its use to predict return of spontaneous circulation, rearrest, and neurologic outcome, and provide suggestions for incorporation of cerebral oximetry into CPR practice.

Cerebral oximetry monitoring using near-infrared spectroscopy during adult procedural sedation: a preliminary study

BACKGROUND AND OBJECTIVES

We sought to evaluate the effect of adult procedural sedation on cerebral oxygenation measured by near-infrared spectroscopy (rSo₂ levels), and to assess whether respiratory depression occurring during procedural sedation was associated with decreases in cerebral oxygenation.

METHODS

We performed a prospective, observational preliminary study on a convenience sample of adult patients (>18 years) undergoing unscheduled procedural sedation in the ED from August 2017 to September 2018 at Hennepin County Medical Center in Minneapolis, Minnesota. The primary outcome measures were rSo₂ values by level of sedation achieved and the incidence of cerebral hypoxaemia during procedural sedation (absolute rSo₂ ≤60 or decrease ≥20% from baseline). The secondary outcome is the decrease in rSo₂ during episodes of respiratory adverse events (AEs), defined by respiratory depression requiring supportive airway measures.

RESULTS

We enrolled 100 patients (53% female). The median (IQR) rSo₂ values (%) by each level of sedation achieved on the Observer Assessment of Alertness and Sedation (OAAS) scale 1-5, respectively, were 74 (69-79), 74 (70-79), 74 (69-79), 75 (69-80), 72 (68-76). The incidence of cerebral hypoxaemia at any point within the sedation (absolute rSo₂ <60%) was 10/100 (10%); 2 out of 10 had rSo₂ reduction more than 20% from baseline value; the median (IQR) observed minimum rSo₂ in these patients was 58 (56-59). We observed respiratory depression in 65 patients via standard monitoring; of these, 39 (60%) required at least one supportive airway measure, meeting the definition of a respiratory AE. During these AEs, 15% (6/39) demonstrated cerebral hypoxaemia with a median (IQR) minimum rSo₂ of 58 (57-59). Four patients (4%) had cerebral hypoxaemia without a respiratory AE.

CONCLUSION

Cerebral oximetry may represent a useful tool for procedural sedation safety research to detect potential subclinical changes that may be associated with risk, but appears neither sensitive nor specific for routine use in clinical practice.

Effectiveness of near-infrared spectroscopy-guided continuous chest compression resuscitation without rhythm check in patients with out-of-hospital cardiac arrest: The prospective multicenter TripleCPR 16 study

BACKGROUND

The proportion of adult patients with return of spontaneous circulation (ROSC) following out-of-hospital cardiac arrest (OHCA) remains unchanged since 2012. A better resuscitation strategy is needed. This study evaluated the effectiveness of a regional cerebral oxygen saturation (rSO₂)-guided resuscitation protocol without rhythm check based on our previous study.

METHODS

Because defibrillation is the definitive therapy that should be performed without delay for shockable rhythm, the study subjects were OHCA patients with non-shockable rhythm on hospital arrival at three emergency departments. They were divided into three groups based on their baseline rSO₂ value (%): ≥50, ≥40 to <50, or <40. Continuous chest compression without rhythm checks was performed for 16 minutes or until a maximum increase in rSO₂ of 10%, 20%, or 35% was achieved in each group, respectively. This intervention cohort was compared with a historical control cohort regarding the probability of ROSC using inverse probability of treatment weighting (IPTW) with propensity score.

RESULTS

The control and intervention cohorts respectively included 86 and 225 patients. The rate of ROSC was not significantly different between the groups (adjusted OR 0.91 [95% CI, 0.64-1.29], P = 0.60), but no serious adverse events occurred. Sensitivity analyses 1 and 2 showed a significant difference or positive tendency for higher probability of ROSC (adjusted OR 1.63 [95% CI, 1.22-2.17], P < 0.001) (adjusted OR 1.25 [95% CI, 0.95-1.63], P = 0.11).

CONCLUSIONS

This trial suggested that a new cardiopulmonary resuscitation protocol with different rhythm check timing could be created using the rSO₂ value. Clinical trial number: UMIN000025684.

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 .

Automated pupillometry helps monitor the efficacy of cardiopulmonary resuscitation and predict return of spontaneous circulation

BACKGROUND

We investigated the effectiveness of automated pupillometry on monitoring cardiopulmonary resuscitation (CPR) and predicting return of spontaneous circulation (ROSC) in a swine model of cardiac arrest (CA).

METHODS

Sixteen male domestic pigs were included. Traditional indices including coronary perfusion pressure (CPP), end-tidal carbon dioxide (ETCO₂), regional cerebral tissue oxygen saturation (rSO₂) and carotid blood flow (CBF) were continuously monitored throughout the experiment. In addition, the pupillary parameters including the initial pupil size before constriction (Init, maximum diameter), the end pupil size at peak constriction (End, minimum diameter), and percentage of change (%PLR) were measured by an automated quantitative pupillometer at baseline, at 1, 4, 7 min during CA, and at 1, 4, 7 min during CPR.

RESULTS

ROSC was achieved in 11/16 animals. The levels of CPP, ETCO₂, rSO₂ and CBF were significantly greater during CPR in resuscitated animals than those non-resuscitated ones. Init and End were decreased and %PLR was increased during CPR in resuscitated animals when compared with those non-resuscitated ones. There were moderate to good significant correlations between traditional indices and Init, End, and %PLR (|r| = 0.46-0.78, all P < 0.001). Furthermore, comparable performance was also achieved by automated pupillometry (AUCs of Init, End and %PLR were 0.821, 0.873 and 0.821, respectively, all P < 0.05) compared with the traditional indices (AUCs = 0.809-0.946).

CONCLUSION

The automated pupillometry may serve as an effective surrogate method to monitor cardiopulmonary resuscitation efficacy and predict ROSC in a swine model of cardiac arrest.

Focused echocardiography, end-tidal carbon dioxide, arterial blood pressure or near-infrared spectroscopy monitoring during paediatric cardiopulmonary resuscitation: A scoping review

AIM

To evaluate the individual use and predictive value of focused echocardiography, end-tidal carbon dioxide (EtCO2), invasive arterial blood pressure (BP) and near-infrared spectroscopy (NIRS) during cardiopulmonary resuscitation (CPR) in children.

METHODS

This scoping review was undertaken as part of the continuous evidence evaluation process of the International Liaison Committee on Resuscitation (ILCOR) and based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) extension for scoping reviews. PubMed, MEDLINE, CINAHL and EMBASE were searched from the last ILCOR reviews until September 2020. We included all published studies evaluating the effect of echocardiography, EtCO2, BP or NIRS guided CPR on clinical outcomes and quality of CPR.

RESULTS

We identified eight observational studies, including 288 children. Two case series reported the use of echocardiography, one in detecting pulmonary emboli, the second in cardiac standstill, where contractility was regained with the use of extracorporeal membrane oxygenation. The two studies describing EtCO2 were ambivalent regarding the association between mean values and any outcomes. Mean diastolic BP was associated with increased survival and favourable neurological outcome, but not with new substantive morbidity in two studies describing an overlapping population. NIRS values reflected changes in EtCO2 and cerebral blood volume index in two studies, with lower values in patients who did not achieve return of circulation.

CONCLUSION

Although there seems some beneficial effect of these intra-arrest variables, higher quality paediatric studies are needed to evaluate whether echocardiography, EtCO2, BP or NIRS guided CPR could improve outcomes.

Brain Injury in Extracorporeal Membrane Oxygenation: A Multidisciplinary Approach

Extracorporeal membrane oxygenation (ECMO) represents an established technique to provide temporary cardiac and/or pulmonary support. ECMO, in veno-venous, veno-arterial or in extracorporeal carbon dioxide removal modality, is associated with a high rate of brain injuries. These complications have been reported in 7 to 15% of adults and 20% of neonates, and are associated with poor survival. Thromboembolic events, loss of cerebral autoregulation, alteration of the blood-brain barrier, and hemorrhage related to anticoagulation represent the main causes of severe brain injury during ECMO. The most frequent forms of acute neurological injuries in ECMO patients are intracranial hemorrhage (2-21%), ischemic stroke (2-10%), seizures (2-6%), and hypoxic-ischemic brain injury; brain death may also occur in this population. Other frequent complications are infarction (1-8%) and cerebral edema (2-10%), as well as neuropsychological and psychiatric sequelae, including posttraumatic stress disorder.

Monitoring tissue oxygenation index using near-infrared spectroscopy during pre-hospital resuscitation among out-of-hospital cardiac arrest patients: a pilot study

Background

Tissue oxygenation index (TOI) using the near infrared spectroscopy (NIRS) has been demonstrated as a useful indicator to predict return of spontaneous circulation (ROSC) among out-of-hospital cardiac arrest (OHCA) patients in hospital setting. However, it has not been widely examined based on pre-hospital setting.

Methods

In this prospective observational study, we measured TOI in pre-hospital setting among OHCA patients receiving cardio-pulmonary resuscitation (CPR) during ambulance transportation between 2017 and 2018. Throughout the pre-hospital CPR procedure, TOI was continuously measured. The study population was divided into two subgroups: ROSC group and non-ROSC group.

Results

Of the 81 patients included in the final analysis, 26 achieved ROSC and 55 did not achieve ROSC. Patients in the ROSC group were significantly younger, had higher ∆TOI (changes in TOI) (5.8 % vs. 1.3 %; p < 0.01), and were more likely to have shockable rhythms and event witnessed than patients in the non-ROSC group. ∆TOI cut-off value of 5 % had highest sensitivity (65.4 %) and specificity (89.3 %) for ROSC. Patients with a cut-off value ≤-2.0 % did not achieve ROSC and while all OHCA patient with a cut-off value ≥ 8.0 % achieved ROSC. In addition, ROSC group had stronger positive correlation between mean chest compression rate and ∆TOI (r = 0.82) than non-ROSC group (r = 0.50).

Conclusions

This study suggests that ∆ TOI could be a useful indicator to predict ROSC in a pre-hospital setting.

The impact of extracorporeal membrane oxygenation on cerebral oxygen delivery during cardiac arrest: a case series

Aim

To describe the impact of extracorporeal membrane oxygenation (ECMO) assisted CPR (E-CPR) on cerebral oxygen delivery during in-hospital cardiac arrest (IHCA).

Methods

Retrospective case series from a tertiary academic medical center. Regional cerebral oxygen saturation (rSO2) was measured continuously using cerebral oximetry in six patients who experienced IHCA. During CPR, the time of E-CPR initiation was recorded, and rSO2 values were subsequently analyzed for a period beginning 5 min before and ending 2.5 min after the initiation of E-CPR.

Results

The average rSO₂ value in the 2.5 min period following E-CPR initiation increased by 20.8% as compared to the 5-min period before E-CPR initiation.

Conclusions

ECMO can be employed in parallel with cerebral rSO2 monitoring during CPR for adult IHCA patients. E-CPR is associated with rapid and significant increases in brain oxygen delivery.

Evaluation of the Quality of Chest Compression with Oxyhemoglobin Level by Near-Infrared Spectroscopy in a Rat Asphyxia Cardiac Arrest Model

The real-time evaluation of chest compression during cardiopulmonary resuscitation is important to increase the chances of survival from a cardiac arrest (CA). In addition, cerebral oxygen level measured by near-infrared spectroscopy (NIRS) plays an important role as an indicator of return of spontaneous circulation. Recently, we developed a new method to improve the quality of chest compression using a thoracic pump in conjunction with the classic cardiac pump in a rat asphyxia CA model. This study evaluated the quality of chest compression using NIRS in male Sprague-Dawley rats. NIRS was attached between the nasion and the upper cervical spine, and rats underwent 10 minute asphyxia CA. After CA, we alternately performed three different types of chest compression (cardiac, thoracic, and cardiac plus thoracic pumps) every 30 seconds for up to 4 and a half minutes. We measured the oxyhemoglobin (Oxy-Hb), deoxyhemoglobin (Deoxy-Hb), and tissue oxygenation index (TOI) and compared these values between the groups. Oxy-Hb was significantly different among the groups (cardiac, thoracic, and cardiac plus thoracic, 1.5 ± 0.9, 4.4 ± 0.7, and 5.9 ± 2.1 μmol/L, p < 0.01, respectively), while Deoxy-Hb and TOI were not (Deoxy-HB -2.7 ± 1.2, -1.1 ± 3.2, and -1.6 ± 10.1 μmol/L; TOI, 1.8 ± 1.8, 5.5 ± 1.3, and 9.5 ± 8.0%, respectively). Oxy-Hb showed potential to evaluate the quality of chest compression in a rat asphyxia CA model.

Pediatric Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for pediatric life support is based on the most extensive evidence evaluation ever performed by the Pediatric Life Support Task Force. Three types of evidence evaluation were used in this review: systematic reviews, scoping reviews, and evidence updates. Per agreement with the evidence evaluation recommendations of the International Liaison Committee on Resuscitation, only systematic reviews could result in a new or revised treatment recommendation. Systematic reviews performed for this 2020 CoSTR for pediatric life support included the topics of sequencing of airway-breaths-compressions versus compressions-airway-breaths in the delivery of pediatric basic life support, the initial timing and dose intervals for epinephrine administration during resuscitation, and the targets for oxygen and carbon dioxide levels in pediatric patients after return of spontaneous circulation. The most controversial topics included the initial timing and dose intervals of epinephrine administration (new treatment recommendations were made) and the administration of fluid for infants and children with septic shock (this latter topic was evaluated by evidence update). All evidence reviews identified the paucity of pediatric data and the need for more research involving resuscitation of infants and children.

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations for advanced life support includes updates on multiple advanced life support topics addressed with 3 different types of reviews. Topics were prioritized on the basis of both recent interest within the resuscitation community and the amount of new evidence available since any previous review. Systematic reviews addressed higher-priority topics, and included double-sequential defibrillation, intravenous versus intraosseous route for drug administration during cardiac arrest, point-of-care echocardiography for intra-arrest prognostication, cardiac arrest caused by pulmonary embolism, postresuscitation oxygenation and ventilation, prophylactic antibiotics after resuscitation, postresuscitation seizure prophylaxis and treatment, and neuroprognostication. New or updated treatment recommendations on these topics are presented. Scoping reviews were conducted for anticipatory charging and monitoring of physiological parameters during cardiopulmonary resuscitation. Topics for which systematic reviews and new Consensuses on Science With Treatment Recommendations were completed since 2015 are also summarized here. All remaining topics reviewed were addressed with evidence updates to identify any new evidence and to help determine which topics should be the highest priority for systematic reviews in the next 1 to 2 years.

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.

Pediatric Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for pediatric life support is based on the most extensive evidence evaluation ever performed by the Pediatric Life Support Task Force. Three types of evidence evaluation were used in this review: systematic reviews, scoping reviews, and evidence updates. Per agreement with the evidence evaluation recommendations of the International Liaison Committee on Resuscitation, only systematic reviews could result in a new or revised treatment recommendation. Systematic reviews performed for this 2020 CoSTR for pediatric life support included the topics of sequencing of airway-breaths-compressions versus compressions-airway-breaths in the delivery of pediatric basic life support, the initial timing and dose intervals for epinephrine administration during resuscitation, and the targets for oxygen and carbon dioxide levels in pediatric patients after return of spontaneous circulation. The most controversial topics included the initial timing and dose intervals of epinephrine administration (new treatment recommendations were made) and the administration of fluid for infants and children with septic shock (this latter topic was evaluated by evidence update). All evidence reviews identified the paucity of pediatric data and the need for more research involving resuscitation of infants and children.

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations for advanced life support includes updates on multiple advanced life support topics addressed with 3 different types of reviews. Topics were prioritized on the basis of both recent interest within the resuscitation community and the amount of new evidence available since any previous review. Systematic reviews addressed higher-priority topics, and included double-sequential defibrillation, intravenous versus intraosseous route for drug administration during cardiac arrest, point-of-care echocardiography for intra-arrest prognostication, cardiac arrest caused by pulmonary embolism, postresuscitation oxygenation and ventilation, prophylactic antibiotics after resuscitation, postresuscitation seizure prophylaxis and treatment, and neuroprognostication. New or updated treatment recommendations on these topics are presented. Scoping reviews were conducted for anticipatory charging and monitoring of physiological parameters during cardiopulmonary resuscitation. Topics for which systematic reviews and new Consensuses on Science With Treatment Recommendations were completed since 2015 are also summarized here. All remaining topics reviewed were addressed with evidence updates to identify any new evidence and to help determine which topics should be the highest priority for systematic reviews in the next 1 to 2 years.

Comparison of manual and mechanical chest compression techniques using cerebral oximetry in witnessed cardiac arrests at the emergency department: A prospective, randomized clinical study

AIM

We aimed to compare regional cerebral oxygen saturation (rSO₂) levels during cardiopulmonary resuscitation (CPR), performed either manually or using a mechanical chest compression device (MCCD), in witnessed cardiac arrest cases in the emergency department (ED), and to evaluate the effects of both the CPR methods and perfusion levels on patient survival and neurological outcomes.

METHODS

This single-center, randomized study recruited patients aged ≥18 years who had witnessed a cardiopulmonary arrest in the ED. According to the relevant guidelines, CPR was performed either manually or using an MCCD. Simultaneously, rSO₂ levels were continually measured with near-infrared spectroscopy.

RESULTS

Seventy-five cases were randomly distributed between the MCCD (n = 40) and manual CPR (n = 35) groups. No significant difference in mean rSO₂ levels was found between the MCCD and manual CPR groups (46.35 ± 14.04 and 46.60 ± 12.09, respectively; p = 0.541). However, a significant difference in rSO₂ levels was found between patients without return of spontaneous circulation (ROSC) and those with ROSC (40.35 ± 10.05 and 50.50 ± 13.44, respectively; p < 0.001). In predicting ROSC, rSO₂ levels ≥24% provided 100% sensitivity (95% confidence interval [CI] 92-100), and rSO₂ levels ≥64% provided 100% specificity (95% CI 88-100). The area under the curve for ROSC prediction using rSO₂ levels during CPR was 0.74 (95% CI 0.62-0.83).

CONCLUSION

A relationship between ROSC and high rSO₂ levels in witnessed cardiac arrests exists. Monitoring rSO₂ levels during CPR would be useful in CPR management and ROSC prediction. During CPR, MCCD or manual chest compression has no distinct effect on oxygen delivery to the brain.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT03238287.

A walk through the progression of resuscitation medicine

Cardiac arrest (CA) is a sudden and devastating disease process resulting in more deaths in the United States than many cancers, metabolic diseases, and even car accidents. Despite such a heavy mortality burden, effective treatments have remained elusive. The past century has been productive in establishing the guidelines for resuscitation, known as cardiopulmonary resuscitation (CPR), as well as developing a scientific field whose aim is to elucidate the underlying mechanisms of CA and develop therapies to save lives. CPR has been successful in reinitiating the heart after arrest, enabling a survival rate of approximately 10% in out-of-hospital CA. Although current advanced resuscitation methods, including hypothermia and extracorporeal membrane oxygenation, have improved survival in some patients, they are unlikely to significantly improve the national survival rate any further without a paradigm shift. Such a change is possible with sustained efforts in the basic and clinical sciences of resuscitation and their implementation. This review seeks to discuss the current landscape in resuscitation medicine-how we got here and where we are going.

Association between cerebral oximetry and return of spontaneous circulation following cardiac arrest: A systematic review and meta-analysis

The present meta-analysis was based on the available studies to determine the potential role of the initial and regional cerebral oxygen saturation (rSO2) in monitoring the efficiency of cardiopulmonary resuscitation (CPR) and predicting the return of spontaneous circulation (ROSC). Three electronic databases of PubMed, Embase, and the Cochrane Library were searched to identify the studies that investigated the role of rSO2 on ROSC in CA patients throughout May 2018. The weighted mean difference (WMD) with 95% confidence interval (CI) was calculated to estimate the pooled effect using a random-effects model. Sensitivity, subgroup analyses, and publication bias were conducted. A total of 13 studies involving 678 CA patients (300 in-hospital (IH) patients, and 378 out-hospital (OH) patients) were included. The summary WMD suggested that ROSC patients were associated with higher initial rSO2 (WMD: 10.10%; 95% CI: 5.66–14.55; P<0.001) and mean rSO2 (WMD: 14.16%; 95% CI: 10.51–17.81; P<0.001) levels during CA and ROSC as compared to the non-ROSC. The results of meta-regression suggested that the male percentage and the location of cardiac arrest might bias the initial or mean rSO2 and the incidence of ROSC. These significant differences were observed in nearly all subsets. The findings of this study suggested that high initial or mean rSO2 levels were both associated with an increased incidence of ROSC in CA patients undergoing CPR. These correlations might be affected by the percentage of males or the location of cardiac arrest, thereby necessitating further large-scale studies to substantiate whether these correlations differ according to gender and the location of cardiac arrest.

Clinical and Technical Limitations of Cerebral and Somatic Near-Infrared Spectroscopy as an Oxygenation Monitor

Cerebral and somatic near-infrared spectroscopy monitors are commonly used to detect tissue oxygenation in various circumstances. This form of monitoring is based on tissue infrared absorption and can be influenced by several physiological and non-physiological factors that can induce error in the interpretation. This narrative review explores those clinical and technical limitations and proposes solutions and alternatives in order to avoid some of those pitfalls.

Personalized physiology-guided resuscitation in highly monitored patients with cardiac arrest-the PERSEUS resuscitation protocol

Resuscitation guidelines remain uniform across all cardiac arrest patients, focusing on the delivery of chest compressions to a standardized rate and depth and algorithmic vasopressor dosing. However, individualizing resuscitation to the appropriate hemodynamic and ventilatory goals rather than a standard "one-size-fits-all" treatment seems a promising new therapeutic strategy. In this article, we present a new physiology-guided treatment strategy to titrate the resuscitation efforts to patient's physiologic response after cardiac arrest. This approach can be applied during resuscitation attempts in highly monitored patients, such as those in the operating room or the intensive care unit, and could serve as a method for improving tissue perfusion and oxygenation while decreasing post-resuscitation adverse effects.

Resuscitating the Globally Ischemic Brain: TTM and Beyond

Cardiac arrest (CA) afflicts ~ 550,000 people each year in the USA. A small fraction of CA sufferers survive with a majority of these survivors emerging in a comatose state. Many CA survivors suffer devastating global brain injury with some remaining indefinitely in a comatose state. The pathogenesis of global brain injury secondary to CA is complex. Mechanisms of CA-induced brain injury include ischemia, hypoxia, cytotoxicity, inflammation, and ultimately, irreversible neuronal damage. Due to this complexity, it is critical for clinicians to have access as early as possible to quantitative metrics for diagnosing injury severity, accurately predicting outcome, and informing patient care. Current recommendations involve using multiple modalities including clinical exam, electrophysiology, brain imaging, and molecular biomarkers. This multi-faceted approach is designed to improve prognostication to avoid "self-fulfilling" prophecy and early withdrawal of life-sustaining treatments. Incorporation of emerging dynamic monitoring tools such as diffuse optical technologies may provide improved diagnosis and early prognostication to better inform treatment. Currently, targeted temperature management (TTM) is the leading treatment, with the number of patients needed to treat being ~ 6 in order to improve outcome for one patient. Future avenues of treatment, which may potentially be combined with TTM, include pharmacotherapy, perfusion/oxygenation targets, and pre/postconditioning. In this review, we provide a bench to bedside approach to delineate the pathophysiology, prognostication methods, current targeted therapies, and future directions of research surrounding hypoxic-ischemic brain injury (HIBI) secondary to CA.

FUNCTIONAL NEAR-INFRARED SPECTROSCOPY-BASED UPPER EXTREMITY FUNCTION REHABILITATION FOR STROKE SURVIVOR: A REVIEW

Recently, the functional near-infrared spectroscopy (600–900[Formula: see text]nm electromagnetic wave) ([Formula: see text]-NIRS)-based rehabilitation researches have been studied for understanding the human brain. Although [Formula: see text]-NIRS can successfully measure the relative blood concentration changes of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) as an assessment tool to identify significant clinical intervention during pre- and post-rehabilitation therapy for stroke survivors, there is insufficient information particularly on the use of [Formula: see text]-NIRS as a clinical translation in upper extremity function rehabilitation. In order to widely utilize the [Formula: see text]-NIRS for upper extremity rehabilitation, device information, experiment design, measurement procedure, and analyzing method are described for clinician aspect in this study. In addition, further research trend was introduced from previous studies for stroke survivor rehabilitation. The authors believed that the information provided in this study can be a useful guideline to encourage future researchers to focus on upper extremity function rehabilitation of stroke survivors.

Prediction of the neurological outcome using regional cerebral oxygen saturation in patients with extracorporeal cardiopulmonary resuscitation after out-of-hospital cardiac arrest: a multicenter retrospective cohort study

Aim

To investigate the association between regional cerebral oxygen saturation (rSO2) and neurological outcomes in extracorporeal cardiopulmonary resuscitation (ECPR) patients after out‐of‐hospital cardiac arrest (OHCA).

Methods

We used data from the Japan‐Prediction of Neurological Outcomes in Patients Post‐Cardiac Arrest Registry. This registry included consecutive comatose patients after OHCA who were transferred to 15 hospitals in Japan from 2011 to 2013. Our primary end‐point was a good neurological outcome (cerebral performance categories 1 or 2) at 90 days after OHCA.

Results

Among the enrolled patients, 121 (6.3%) received ECPR. Eleven (9.1%) had a good neurological outcome. Receiver operating characteristic curve analysis revealed the optimal cut‐off value as >16%. Good neurological outcomes were observed in 19.6% (9/46) and 2.7% (2/74) of patients with rSO2 >16% and rSO2 ≤16%, respectively.

Conclusion

The neurological outcome of ECPR patients differed according to their rSO2 values. When considering ECPR, the rSO2 value could be important in addition to other criteria. Further studies that focus on ECPR patients and serial rSO2 values are needed.

Effects of therapeutic hypothermia on cerebral tissue oxygen saturation in a swine model of post-cardiac arrest

Since the introduction of therapeutic hypothermia (TH), trends have changed in the monitoring indicators used during and after cardiac arrest. During hypothermia, the cerebral metabolic rate of oxygen is reduced, which leads to uncertainty in regional cerebral tissue oxygen saturation (S_ctO₂). The aim of the present study was to evaluate the effect of TH on changes in S_ctO₂ using near-infrared spectroscopy. A total of 23 male domestic pigs were randomized into three groups: TH (n=9), normothermia (NT; n=9) and control (n=5). Animals in the control group underwent surgical preparation only. The animal models were established using 8 min of ventricular fibrillation and 5 min of cardiopulmonary resuscitation. In the TH group, at 5 min after resuscitation, the animals were cooled with a cooling blanket and ice packs for 24 h. S_ctO₂ was recorded throughout the experiment. In all groups, The mean arterial pressure, arterial carbon dioxide partial pressure, arterial oxygen partial pressure, lactate, neuron-specific enolase (NSE) and S100B were measured at baseline and at 1, 3, 6, 12, 24 and 30 h after resuscitation. S_ctO₂ significantly decreased after ventricular fibrillation, compared with the baseline. Following resuscitation, the S_ctO₂ values gradually increased to 55.6±3.8% of baseline in the TH group and 51.2±3.5% in the NT group (P=0.039). Significant differences between the two groups were observed, starting at 6 h after cardiac arrest. Throughout the hypothermic period, NSE and S100B showed an increasing trend, then decreased during rewarming in the TH and NT groups. NSE and S100B showed greater improvement in the TH group compared with the NT group at 6 and 24 h after resuscitation. Following cardiac arrest, therapeutic hypothermia could increase S_ctO₂ after resuscitation and could improve neurological outcome. In conclusion, S_ctO₂ may be a feasible marker for use in the early assessment of brain damage during and after cardiac arrest.

Electroencephalography and Brain Oxygenation Monitoring in the Perioperative Period

Maintaining brain function and integrity is a pivotal part of anesthesiological practice. The present overview aims to describe the current role of the 2 most frequently used monitoring methods for evaluation brain function in the perioperative period, ie, electroencephalography (EEG) and brain oxygenation monitoring. Available evidence suggests that EEG-derived parameters give additional information about depth of anesthesia for optimizing anesthetic titration. The effects on reduction of drug consumption or recovery time are heterogeneous, but most studies show a reduction of recovery times if anesthesia is titrated along processed EEG. It has been hypothesized that future EEG-derived indices will allow a better understanding of the neurophysiological principles of anesthetic-induced alteration of consciousness instead of the probabilistic approach most often used nowadays.Brain oxygenation can be either measured directly in brain parenchyma via a surgical burr hole, estimated from the venous outflow of the brain via a catheter in the jugular bulb, or assessed noninvasively by near-infrared spectroscopy. The latter method has increasingly been accepted clinically due to its ease of use and increasing evidence that near-infrared spectroscopy-derived cerebral oxygen saturation levels are associated with neurological and/or general perioperative complications and increased mortality. Furthermore, a goal-directed strategy aiming to avoid cerebral desaturations might help to reduce these complications. Recent evidence points out that this technology may additionally be used to assess autoregulation of cerebral blood flow and thereby help to titrate arterial blood pressure to the individual needs and for bedside diagnosis of disturbed autoregulation.