Return Of Spontaneous Circulation Time Research Articles

Impact of time to revascularization on outcomes in patients after out-of-hospital cardiac arrest with STEMI

BackgroundInternational guidelines recommend emergency coronary angiography in patients after out-of-hospital cardiac arrest (OHCA) with ST-segment elevation on 12‑lead electrocardiography. However, the association between time to revascularization and outcomes remains unknown. This study aimed to evaluate the association between time to revascularization and outcomes in patients with OHCA due to ST-segment-elevation myocardial infarction (STEMI) who underwent percutaneous coronary intervention (PCI). MethodsThis multicenter, retrospective, nationwide observational study included patients aged ≥18 years with OHCA due to STEMI who underwent PCI between 2014 and 2020. The time of the first return of spontaneous circulation (ROSC) was defined as the time of first ROSC during resuscitation, regardless of the pre-hospital or in-hospital setting. The primary outcome was a 1-month favorable neurological outcome, defined as cerebral performance category 1 or 2. Multivariable logistic regression analysis was used to assess the association between the time to revascularization and favorable neurological outcomes. ResultsA total of 547 patients were included in this analysis. The multivariable logistic regression analysis showed that a shorter time from the first ROSC to revascularization was associated with 1-month favorable neurological outcomes (63/86 [73.3%] in the time from the first ROSC to revascularization ≤60 min group versus 98/193 [50.8%] in the >120 min group; adjusted OR, 0.26; 95% CI, 0.11–0.56; P for trend, 0.015). ConclusionsShorter time to revascularization was significantly associated with 1-month favorable neurological outcomes in patients with OHCA due to STEMI who underwent PCI.

Blood pressure immediately after return of spontaneous circulation is associated with increased survival on admission following out‐of‐hospital cardiac arrest

AbstractBackgroundIn patients with out‐of‐hospital cardiac arrest (OHCA), low blood pressure after return of spontaneous circulation (ROSC) can be a sign of hemodynamic instability. We aimed to investigate whether systolic blood pressure (SBP) measured immediately after ROSC is associated with survival on admission.MethodsPatients with ROSC after OHCA between 2015 and 2018 were included. The primary outcome was survival on admission. Included patients were divided into three groups based on the SBP measured at the time of ROSC: group 1 (SBP ≤90 mmHg), group 2 (SBP 90–120 mmHg), and group 3 (SBP >120 mmHg). Multivariable logistic regression was used to investigate the relationship between the groups by SBP and outcomes.ResultsIn the final analysis, 519 patients were included. In the restrictive cubic spline curve, the probability of achieving survival on admission increased gradually from low SBP to approximately 120–130 mmHg, then plateaued at a higher SBP. In the multivariable logistic regression analysis, group 1 was independently associated with decreased survival on admission compared to group 2. There was no significant difference between groups 2 and 3.ConclusionsLow blood pressure (SBP ≤90 mmHg) at the time of ROSC was independently associated with a lower likelihood of survival on admission in patients with non‐traumatic OHCA. However, high blood pressure (SBP >120 mmHg) was not associated with a higher likelihood of survival. These suggest that low blood pressure measured in the prehospital phase can serve as an indicator predicting the poor short‐term prognosis of patients.

A new method to evaluate carotid blood flow by continuous Doppler monitoring during cardiopulmonary resuscitation in a porcine model of cardiac arrest

AimWe used a wearable carotid Doppler patch to study carotid blood flow patterns in a porcine model of cardiac arrest to identify return of spontaneous circulation (ROSC) and hemodynamics associated with different arrhythmias and the quality of compressions. MethodsTwenty Landrace pigs were used as models of cardiac arrest following a standard protocol. Carotid blood flow was monitored continuously using noninvasive ultrasound. Carotid spectral waveforms were captured during various arrhythmias and CPR. Typical carotid blood flow waveforms were recorded at the time of ROSC, and hemodynamic changes were compared with carotid blood flow parameters. ResultsThe results showed that the carotid blood flow waveforms varied with ventricular arrhythmia type. During CPR, compression depth correlated significantly with carotid maximal velocity (Vmax) (Spearman correlation coefficient (r) = 0.682, P < 0.001) and velocity–time integral (VTI) (r = 0.794, P < 0.001). Vmax and VTI demonstrated moderate predictive value for survival. The regular carotid blood flow pattern towards the brain was observed during ROSC, concurrent with compression waveforms. After ROSC, VTI and carotid pulse volume (cPV) showed similar trends as stroke volume (SV). The carotid minute volume (cMV) exhibited a similar trend as cardiac output (CO). ConclusionsCarotid blood flow monitoring could provide valuable information about different arrhythmias as well as the quality of CPR. Carotid flow monitoring allows for timely and effective identification of ROSC. In addition, it may provide valuable hemodynamic information after ROSC.

Study on anisodamine hydrobromide improves Th17/Treg imbalance in resuscitated pigs

To investigate whether anisodamine can regulate the ratio of helper T helper cells/regulatory T cells (Th17/Treg) and its protective effect on animals after resuscitation. Twenty-four Beijing white minipigs were randomly divided into sham operation group (Sham group), resuscitation and normal saline group (SA group), and resuscitation and anisodamine hydrobromide group (AH group), with 8 pigs in each group. In SA group and AH group, ventricular fibrillation was induced by continuous stimulation with intraventricular electrodes for 8 minutes and then resuscitated to establish ischemia/reperfusion (I/R) model. In SA group, after cardiopulmonary resuscitation (CPR), only normal saline was intravenously infused, while in AH group, normal saline and anisodamine hydrobromide were given intravenously at the same time point. Hemodynamic indexes, arterial blood gas analysis indexes, interleukins (IL-17, IL-10) levels in venous blood and IL-17/IL-10 ratio were recorded at 6 different time points: baseline, immediately after return of spontaneous circulation (ROSC), 1 hour, 2 hours, 4 hours and 6 hours after ROSC. The animals were sacrificed at 6 hours after ROSC, and intestinal lymphatic tissues were taken to observe pathological changes under light microscope. At the same time, the levels of IL-17 and IL-10 in intestinal lymphatic tissue were measured (the ratio of IL-17/IL-10 represents the ratio of Th17/Treg cytokines) to evaluate the immune status of the resuscitated animals. The bacterial translocations of different groups were evaluated by culturing intestinal lymphoid tissue. With the extension of ROSC time, the levels of IL-17 in venous blood and the IL-17/IL-10 ratio in pig blood samples continued to decrease, while the levels of IL-10 continued to increase. From 2 hours after ROSC, the IL-17/IL-10 ratio in AH group was significantly higher than that in SA group continued until at 6 hours after ROSC (0.79±0.05 vs. 0.49±0.08, P < 0.05). Light microscopy showed that the number and size of lymph nodules in the cortex of intestinal lymphatic tissue were less in AH group, compared with SA group. Compared with Sham group, the levels of IL-17 and IL-17/IL-10 ratio also decreased in intestinal lymphatic tissue at 6 hours after ROSC [IL-17 (ng/L): 155.23±0.92, 178.76±7.25 vs. 209.21±19.82, IL-17/IL-10 ratio: 1.43±0.13, 1.92±0.18 vs. 3.30±0.31, all P < 0.05], and IL-10 increased significantly (ng/L: 109.85±11.60, 93.55±81.83 vs. 63.45±0.62, all P < 0.05); IL-17/IL-10 ratio in AH group was significantly higher than that in SA group (1.92±0.18 vs. 1.43±0.13, P < 0.05). Tissue culture indicated the intestinal bacterial translocation after resuscitation, suggesting that the animals had immunosuppression and the increased risk of intestinal secondary infection after resuscitation. Compared with SA group, the risk of bacterial translocation was lower than that in AH group [62.5% (5/8) vs. 87.5% (7/8), P < 0.05]. Anisodamine plays an immunomodulatory role by affecting the balance of Th17/Treg cytokines in resuscitated animals, so as to reduce the risk of intestinal secondary infection and has an organ protective effect.

Ventilation With or Without Endotracheal Tube Leak in Prolonged Neonatal Asphyxia.

BackgroundSevere and prolonged asphyxia can result in either intrauterine fetal death and stillbirth or multiorgan failure in surviving neonates. Establishing effective ventilation is the primary aim of resuscitation in newborns with asphyxia. The objective of this study was to compare the outcome of resuscitation by applying an endotracheal tube (ETT) with less, an ETT with moderate, and an ETT with high leakage during mechanical ventilation in swine neonates after prolonged perinatal asphyxia.Materials and methodsA prospective, randomized controlled laboratory study was performed. Thirty Landrace/large white pigs, aged one to four days and weighted 1.754±218 gr, were randomly allocated into three groups depending on the ETT size: Group C (less leak: ETT no 4.0, n=10); Group A (high leak: ETT no 3.0, n=10); and Group B (moderate leak: ETT no 3.5, n=10). Mechanical asphyxia was performed until their heart rate was less than 60 bpm or their mean arterial pressure was below 15 mmHg. All animals with return of spontaneous circulation (ROSC) were monitored for four hours for their hemodynamic parameters, arterial oxygen saturation, and lactate acid levels.ResultsWe demonstrate that 70% of the surviving animals were ventilated with an ETT with a leak (no. 3.5 and 3). A statistically significant difference was noted in PO2 (p=0.032) between Group B (126.4±53.4 mmHg) compared to Group A (72.28±29.18 mmHg) and Group C (94.28±20.46 mmHg) as well as in the right atrial pressure (p<0.001) between Group C (4.5 mmHg) vs Groups A (2 mmHg) and B (2 mmHg) during ROSC time. Lactate levels were statistically significantly lower (p=0.035) in Group C (mean=0.92 ± 0.07mmol/L) as compared to Group A (mean=1.13 ± 0.1 mmol/L) and Group B (mean= 1.08 ± 0.07 mmol /L; p = 0.034) at 4h post-ROSC.ConclusionWe provide preliminary evidence that ventilation with ETT with moderate leakage improves survival after 2h of ROSC, along with oxygenation and hemodynamic parameters, in a porcine model of neonatal asphyxia and resuscitation, compared to less leakage ETT.

Changes of regional saturation of cerebral oxygenation and neuron specific enolase in patients after cardiopulmonary resuscitation

To observe the changes of regional saturation of cerebral oxygenation (rScO2) and blood neuron specific enolase (NSE) in patients after cardiopulmonary resuscitation (CPR), and to explore its value in evaluating the prognosis of patients' neurological function. From January 2012 to December 2020, 97 patients with return of spontaneous circulation (ROSC) after cardiac arrest (CA) treated in the intensive care unit (ICU) of the Second Affiliated Hospital of Soochow University were selected. According to the prognosis, the patients were divided into two groups: good neurological function group [Glasgow-Pittsburgh Cerebral Performance Categories (CPC) 1-2, 20 cases] and neurological dysfunction group (CPC classification 3-5, 77 cases). The clinical data of gender, age, the number of patients with defibrillable rhythm, time of ROSC, the number of CA patients outside the hospital, acute physiology and chronic health evaluation II (APACHE II), Glasgow coma scale (GCS), global non-response scale (FOUR), body temperature, mean arterial pressure (MAP), blood lactic acid (Lac) and GCS at discharge, as well as the length of ICU stay, rScO2 and blood NSE were collected. The differences of rScO2 and NSE between the two groups were compared; and the receiver operator characteristic curve (ROC curve) was drawn to evaluate the value of rScO2 and NSE alone or in combination in predicting the prognosis of patients with ROSC after CA. The rScO2 of good neurological function group was significantly higher than that of neurological dysfunction group at 1, 3, 6, 12, 24 and 48 hours (all P < 0.05). At 24 hours after admission, the rScO2 on the left and right sides of good neurological function group was significantly higher than that in neurological dysfunction group [left: 0.65 (0.59, 0.76) vs. 0.55 (0.44, 0.67), right: 0.62 (0.61, 0.73) vs. 0.50 (0.30, 0.69), both P < 0.05], and NSE was significantly lower than that in the neurological dysfunction group [ng/L: 21.42 (15.38, 29.69) vs. 45.82 (24.05, 291.26), P < 0.05]. ROC curve analysis showed that both rScO2 and NSE alone and combined detection had a certain value in predicting the prognosis of neurological function in patients with ROSC after CA, and the area under the ROC curve (AUC) detected by the combination was the largest, which was higher than the AUC predicted by rScO2 or NSE (0.904 vs. 0.884, 0.792). When the cut-off value of combination was 0.83, the sensitivity and specificity were 75.7% and 100% respectively. Monitoring rScO2 and NSE can predict the prognosis of neurological function after CPR, especially the combined evaluation of the two indexes, which can greatly improve the accuracy of diagnosis.

Multimodal monitoring including early EEG improves stratification of brain injury severity after pediatric cardiac arrest

AimsAssessment of brain injury severity early after cardiac arrest (CA) may guide therapeutic interventions and help clinicians counsel families regarding neurologic prognosis. We aimed to determine whether adding EEG features to predictive models including clinical variables and examination signs increased the accuracy of short-term neurobehavioral outcome prediction. MethodsThis was a prospective, observational, single-center study of consecutive infants and children resuscitated from CA. Standardized EEG scoring was performed by an electroencephalographer for the initial EEG timepoint after return of spontaneous circulation (ROSC) and each 12-h segment from the time of ROSC up to 48 h. EEG Background Category was scored as: (1) normal; (2) slow-disorganized; (3) discontinuous or burst-suppression; or (4) attenuated-featureless. The primary outcome was neurobehavioral outcome at discharge from the Pediatric Intensive Care Unit. To develop the final predictive model, we compared areas under the receiver operating characteristic curves (AUROC) from models with varying combinations of Demographic/Arrest Variables, Examination Signs, and EEG Features. ResultsWe evaluated 89 infants and children. Initial EEG Background Category was normal in 9 subjects (10%), slow-disorganized in 44 (49%), discontinuous or burst suppression in 22 (25%), and attenuated-featureless in 14 (16%). The final model included Demographic/Arrest Variables (witnessed status, doses of epinephrine, initial lactate after ROSC) and EEG Background Category which achieved AUROC of 0.9 for unfavorable neurobehavioral outcome and 0.83 for mortality. ConclusionsThe addition of standardized EEG Background Categories to readily available CA variables significantly improved early stratification of brain injury severity after pediatric CA.

Assessment of Cerebral Blood Oxygenation by Near-Infrared Spectroscopy before and after Resuscitation in a Rat Asphyxia Cardiac Arrest Model.

Clinical investigators have focused on the real-time evaluation of cerebral blood oxygenation (CBO) by near-infrared spectroscopy (NIRS) during cardiopulmonary resuscitation (CPR). A previous study showed that an abrupt increase of oxy-hemoglobin (Hb) level and tissue oxygenation index (TOI) was associated with the timing of return of spontaneous circulation (ROSC). However, it is not clear how TOI alters before and after CPR including a period of cardiac arrest (CA). Therefore, this study aimed to assess CBO with asphyxia CA and its association with CPR to ROSC in rats. Male Sprague-Dawley rats were used. We attached NIRS (NIRO-200NX, Hamamatsu Photonics, Japan) from the nasion to the upper cervical spine in rats. A ten-minute asphyxia was given to induce CA. After CA, mechanical ventilation was restarted, and manual CPR was performed. We examined the mean arterial pressure (MAP), end-tidal carbon dioxide (ETCO2), and Oxy/Deoxy-Hb and TOI. Out of 14 rats, 11 obtained sustained ROSC. After the induction of asphyxia, a rapid drop of TOI was observed, followed by a subsequent increase of Oxy-Hb, Deoxy-Hb, and TOI with CPR. Recent CPR guidelines suggest the use of ETCO2 during CPR since its abrupt increase is a reasonable indicator of ROSC. In this study, abrupt increases in MAP, ETCO2, and TOI were observed at the time of ROSC. TOI can be an alternative to ETCO2 for identifying ROSC after CA, and it also has the capability of monitoring CBO during and after CPR.

Abstract 314: Cardiac Arrest Related Cognitive Activity

Background: Few studies have examined the psychological outcomes of cardiac arrest (CA) survivors. While some negative outcomes including post-traumatic disorder, anxiety and depression have been reported in ~50%, interestingly, ~10-20% of CA survivors have reported lucid, well-structured thought processes during CA associated with positive psychological outcomes and transformation post CA. We aimed to characterize the themes describing the cognitive experiences recalled by survivors. Method: In a qualitative study 118 self-reported cases were extracted from a CA survivor registry, coded the data using thematic analysis to identify emerging themes followed by descriptive statistics to identify frequencies of identified themes. Results: Analysis of 69 in-hospital and 45 out-of-hospital CA events led to identification of 10 major and 64 sub-themes describing the breadth of CA survivors’ cognitive experiences. Most predominate features included having no sense of pain during on-going CPR (18%), perception of being separate from the body (46%), observing the body from a point outside (40%), travelling through a tunnel towards a destination (16%) and having a life review (19%). Interestingly, in the life-review category 87% perceived the life-review to be an educational experience focused on their actions and intentions towards others, 38% described reliving of certain actions with a sense of shame, and 18% perceived to examine life events from others’ perspective. In addition, another category of cognitive experiences were also described that appeared to relate to events during recovery of consciousness around the time of return of spontaneous circulation (ROSC) where 14% of survivors sensed the pressure of CPR and 18% woke up with pain. Conclusion: CA survivor’s memories appear to reflect two categories: 1) a life review and perception of observing themselves during CPR without pain, which is felt to be educational, positive and peaceful and 2) memories related to the recovery phase around the time of ROSC. These include sensing CPR related events such as pain, chest pressure and distress. While the former category may explain the long-term positive transformation, the latter may explain the long-term occurrence of PTSD and anxiety in CA survivors.

The Association of Extreme Tachycardia and Sustained Return of Spontaneous Circulation after Nontraumatic Out-of-Hospital Cardiac Arrest.

Objective Heart rate (HR), an essential vital sign that reflects hemodynamic stability, is influenced by myocardial oxygen demand, coronary blood flow, and myocardial performance. HR at the time of the return of spontaneous circulation (ROSC) could be influenced by the β1-adrenergic effect of the epinephrine administered during cardiopulmonary resuscitation (CPR), and its effect could be decreased in patients who have the failing heart. We aimed to investigate the association between HR at the time of ROSC and the outcomes of adult out-of-hospital cardiac arrest (OHCA) patients. Methods This study was a secondary analysis of a cardiac arrest registry from a single institution from January 2008 to July 2014. The OHCA patients who achieved ROSC at the emergency department (ED) were included, and HR was retrieved from an electrocardiogram or vital sign at the time of ROSC. The patients were categorized into four groups according to the HR (bradycardia (HR < 60), normal HR (60 ≤ HR ≤ 100), tachycardia (100 < HR < 150), and extreme tachycardia (HR ≥ 150)). The primary outcome was the rate of sustained ROSC and the secondary outcomes were the rate of one-month survival and six-month good neurologic outcome. Results A total of 330 patients were included. In the univariate logistic regression model, the rate of sustained ROSC increased by 17% as HR increased by every 10 beats per minute (bpm) (odds ratio (OR), 1.171; 95% confidence interval (CI), 1.077–1.274, p < 0.001). In the multivariate logistic regression model, extreme tachycardia was independently associated with a high probability of sustained ROSC compared to normal heart rate (OR, 15.96; 95% CI, 2.04–124.93, p=0.008). Conclusion Extreme tachycardia (HR ≥ 150) at the time of ROSC is independently associated with a high probability of sustained ROSC in nontraumatic adult OHCA patients.

Abstract 280: Evaluation of Cerebral Blood Oxygenation by NIRS During Asphyxia Cardiac Arrest and Resuscitation in Rats

Background: Clinical investigators have focused on the real-time evaluation of cerebral blood oxygenation (CBO) by near-infrared spectroscopy (NIRS) during cardiopulmonary resuscitation (CPR). A previous study showed that an abrupt increase of Oxy-hemoglobin (Hb) concentration and tissue oxygenation index (TOI) was associated with the timing of return of spontaneous circulation (ROSC). However, it is not clear how TOI decreases in cardiac arrest (CA) and increases by resuscitation. Therefore, this study aimed to assess CBO with asphyxia CA and its association with CPR to ROSC in rats Method: Male Sprague-Dawley rats were used. We attached NIRS (NIRO-200NX, Hamamatsu Photonics, Japan) from nasion to upper cervical spine in rats. 10-minute asphyxia was given to induce CA. After CA, mechanical ventilation was restarted, and manual CPR was performed. We examined the mean arterial pressure (MAP), end-tidal carbon dioxide (ETCO2), and Oxy/Deoxy-Hb and TOI. Results: Out of 12 rats, 9 obtained sustained ROSC. After the induction of asphyxia, TOI rapidly dropped, and as subsequent CPR was undergoing, Oxy-Hb, Deoxy-Hb, and TOI increased in synchrony with chest compressions. And then, an abrupt increase in MAP, ETCO2, and TOI observed at the time of ROSC. Conclusion: Recent CPR guidelines suggest a use of ETCO2 during CPR since its abrupt increase is a reasonable indicator of ROSC. TOI can be an alternative of ETCO2, and in addition, it has the potential to serve as monitoring CBO during CPR and subsequently in post-ROSC care.

Asynchronous ventilation at 120 compared with 90 or 100 compressions per minute improves haemodynamic recovery in asphyxiated newborn piglets

ObjectiveTo determine whether different chest compression (CC) rates during continuous CC with asynchronous ventilations (CCaV) reduce time to return of spontaneous circulation (ROSC) and improved haemodynamic recovery in piglets aged...

Deep-learning-based out-of-hospital cardiac arrest prognostic system to predict clinical outcomes

AimOut-of-hospital cardiac arrest (OHCA) is a major healthcare burden, and prognosis is critical in decision-making for treatment and the withdrawal of life-sustaining therapy. This study aimed to develop and validate a deep-learning-based out-of-hospital cardiac arrest prognostic system (DCAPS) for predicting neurologic recovery and survival to discharge. MethodsThe study subjects were patients from the Korea OHCA registry who experienced return of spontaneous circulation (ROSC) after OHCA. A total of 36,190 patients were exclusively divided into a set of 28,045 subjects for derivation data and 8,145 subjects for validation data. We used information available for the time of ROSC as predictor variables, and the endpoints were neurologic recovery (cerebral performance category 1 or 2) and survival to discharge. The DCAPS was developed using the derivation data and represented the favorability of prognosis with a score between 0 and 100. ResultsThe area under the receiver operating characteristic curve (AUROC) of DCAPS for predicting neurologic recovery for the validation data was 0.953 [95% confidence interval 0.952–0.954]; these results significantly outperformed those of logistic regression (0.947 [0.943–0.948]), random forest (0.943 [0.942–0.945]), support vector machine (0.930 [0.929–0.932]), and conventional methods of a previous study (0.817 [0.815–0.820]). The AUROC of the DCAPS for survival to discharge was 0.901 [0.900–0.903], and this result significantly outperformed those of other models as well. ConclusionsThe DCAPS predicted neurologic recovery and survival to discharge of OHCA patients accurately and outperformed the conventional method and other machine-learning methods.

383 Neurofilament Light Chain as a Marker for Cerebral Anoxia in Out-of-Hospital Cardiac Arrest

Nationwide survival rates for out-of-hospital cardiac arrest (OHCA) approximate around 10-20% despite aggressive intervention. Approximately 90% of survivors will have moderate to severe neurological injury ranging from moderate cognitive impairment to brain death. There is a lack of early prognostic indicators. Traumatic brain injury studies have demonstrated that levels of blood biomarkers of neurological injury are reflective of degree of injury sustained. These biomarkers may be of prognostic value in OHCA patients where anoxic cerebral injury occurs. Non-traumatic OHCA patients ≥ 18 years old, with sustained return of spontaneous circulation (ROSC) for >1 hour were prospectively enrolled. Blood was collected within 59 minutes of ROSC, every 6 hours the first 24 hours, and then daily up to day 6. Patients were followed to day 6 post-OHCA, hospital discharge, or death, whichever occurred first. APACHE II and FOUR scores were recorded daily from time of ROSC (baseline) up to day 6. Five biomarkers of neuroinjury were analyzed: NF-L, GFAP, UCHL-1, Tau, and S100B. Cerebral Performance Category (CPC) was determined at 24 hours of ROSC and by death or within 24 hours before discharge. Primary outcomes were survival to discharge, and good versus poor (CPC 1-2 versus CPC 3-5) neurological outcome at 24 hours and discharge. The association between the biomarkers and other variables were assessed by using the Wilcoxon rank-sum test. Person correlation coefficient was used to assess the relationship between the biomarkers and continuous variables. All tests were performed with a 5% error rate. 13 OHCA patients were enrolled. Participants were mostly males (62%) with an average age of 60.5±9.6 (range 42-73) years. Their presenting rhythm was most often asystole (30.8%), VT/VF (46.2%), or PEA (23.1%). 38.5% of patients survived to discharge. Mean APACHE II at baseline did not significantly differ at 24 hours (26.38 versus 26.31). Of the biomarkers assayed, mean NF-L was significantly different between good versus poor outcome at 24 hours (1244.74 pg/mL versus 966.22 pg/mL, p=0.018), and remained consistently higher in poor outcome group at discharge (21.84 pg/mL versus 1556.46 pg/mL, p=0.012). NF-L levels also correlated with FOUR score at baseline and at 24 hours (p=0.026 and 0.027 respectively), as well as GCS at baseline and 24 hours (p=0.016). Early serum biomarker assays may be supportive in correlating with clinical outcomes and prognostication in out-of-hospital cardiac arrest. We report early pilot data demonstrating the promise of neurofilament light chain as a part of a strategy in supporting the clinical assessment of ischemic brain injury in post cardiac arrest patients.

Effects of different durations of sustained inflation during cardiopulmonary resuscitation on return of spontaneous circulation and hemodynamic recovery in severely asphyxiated piglets

ObjectiveWe previously demonstrated that sustained inflation (SI) during chest compression (CC) significantly reduces time to return of spontaneous circulation (ROSC) when compared to 3:1 compression:ventilation (C:V) ratio during neonatal resuscitation. However, the optimal length of SI during CC to improve ROSC and hemodynamic recovery in severely asphyxiated piglets is unknown. AimTo examine if different lengths of SI will improve ROSC and hemodynamic recovery in severely asphyxiated piglets. Intervention and measurementsThirty newborn piglets (1–3 days) were anesthetized, intubated, instrumented and exposed to 30-min normocapnic hypoxia followed by asphyxia. Piglets were randomized into four groups: 3:1 C:V (n = 8), CC with an SI duration of either 20 s (CC+SI 20) (n = 8) or 60 s (CC+SI 60) (n = 8), and a sham group (n = 6). Cardiac function, carotid blood flow, cerebral and renal oxygenation as well as respiratory parameters were continuously recorded throughout the experiment. Main resultsWhen compared with 3:1 group, both CC+SI 20 and CC+SI 60 groups had significantly shorter ROSC time (p = 0.002). All three intervention groups had similar hemodynamic recovery by the end of 4 h observation period. There was no difference in lung injury markers among all experimental groups. However, when compared to the sham group, the concentrations of IL-6 (thalamus) and IL-6 + IL-8 (frontoparietal cortex) of the 3:1 C:V group were significantly higher, respectively. ConclusionsEven though relatively less animals achieved ROSC, CC during SI significantly improved ROSC time compared to 3:1 C:V in asphyxiated newborn piglets. However, there was no difference in ROSC characteristics and hemodynamic recovery between two CC+SI groups.

Predicting ROSC in out-of-hospital cardiac arrest using expiratory carbon dioxide concentration: Is trend-detection instead of absolute threshold values the key?

AimGuidelines recommend detecting return of spontaneous circulation (ROSC) by a rising concentration of carbon dioxide in the exhalation air. As CO2 is influenced by numerous factors, no absolute cut-off values of CO2 to detect ROSC are agreed on so far. As trends in CO2 might be less affected by influencing factors, we investigated an approach which is based on detecting CO2-trends in real-time. MethodsWe conducted a retrospective case-control study on 169 CO2 time series from out of hospital cardiac arrests resuscitated by Muenster City Ambulance-Service, Germany. A recently developed statistical method for real-time trend-detection (SCARM) was applied to each time series. For each series, the percentage of time points with detected positive and negative trends was determined. ResultsROSC time series had larger percentages of positive trends than No-ROSC time series (p=0.003). The median percentage of positive trends was 15% in the ROSC time series (IQR: 5% to 23%) and 7% in the No-ROSC time series (IQR: 3% to 14%). A receiver operating characteristic (ROC) analysis yielded an optimal threshold of 13% to differentiate between ROSC and No-ROSC cases with a specificity of 58.4% and sensitivity of 73.9%; the area under the curve was 63.5%. ConclusionPatients with ROSC differed from patients without ROSC as to the percentage of detected CO2 trends, indicating the potential of our real-time trend-detection approach. Since the study was designed as a proof of principle and its calculated specificity and sensitivity are low, more research is required to implement CO2-trend-detection into clinical use.

Analysis of out-of-hospital emergency treatment for ventricular fibrillation between 2013 and 2016 in Shanghai

To investigate the epidemiological features of out-of-hospital patients with ventricular fibrillation (VF) in Shanghai and to analysis factors associated with outcomes, and to provide evidence for improving the success rate of VF. The data of patients with VF admitted to Shanghai Medical Emergency Center from January 2013 to December 2016 were analyzed retrospectively. All the data were recorded including the clinical data, medical service time, return of spontaneous circulation (ROSC) at scene/en route, survival to hospital discharge. Factors that associated with successful resuscitation were analyzed by Logistic regression. From 2013 to 2016, 21 096 patients with suspected cardiac arrest were admitted to the Shanghai Medical Emergency Center. After excluding ventricular tachycardia (13 cases) and ventricular asystole (20 995 cases), 88 patients with VF were enrolled, with 62 male and 26 female; the average age was (63.22±16.15) years old. While bystander cardiopulmonary resuscitation (CPR) was performed in only 21 cases (23.86%). Fifty-seven cases occurred during the day (08:00-20:00), while 31 cases occurred in the night. And the average emergency response time was (6.47±4.13) minutes; the average on-site time was (14.76±10.88) minutes; the average transport to hospital time was (5.95±4.00) minutes. There were no significant differences in response time, on-site time and transport to hospital time each year, and there were no significant differences in emergency medical service time between day and night either. From 2013 to 2016, prehospital successful resuscitation rate was decreased by years [95.65% (22/23), 87.50% (14/16), 83.33% (20/24) vs. 80.00% (20/25), respectively, χ2 = 1.895, P = 0.595]. Survival to hospital discharge rate was increased by years [21.74% (5/23), 31.25% (5/16), 37.50% (9/24), 40.00% (10/25), respectively, χ 2 = 2.862, P = 0.413]. The success rate of prehospital resuscitation for patients with 1, 2, ≥3 defibrillation was 35.23% (31/88), 23.08% (12/52), 89.19% (33/37), respectively (χ2 = 42.811, P = 0.000). The on-site time in successful final resuscitation group was shorter than that in final resuscitation failure group (minutes: 10.85±8.83 vs. 16.79±11.36, t = 2.367, P = 0.020), the ROSC time in successful final resuscitation group was shorter than that of final resuscitation failure group (minutes: 3.24±3.17 vs. 7.43±6.64, t = 3.175, P = 0.002). It was shown by Logistic regression that long ROSC time was the risk factor for final resuscitation failure [odds ratio (OR) = 0.771, P = 0.024]. Gender, age, availability of witnesses CPR, call time, emergency response time, on-site time and transport to hospital time had no significant impact on the prehospital successful resuscitation and final successful resuscitation. In prehospital successful resuscitation group, there was significant difference in survival to hospital discharge rate among different defibrillation times group [48.39% (15/31), 58.33% (7/12) vs. 21.21% (7/33), χ2 = 7.460, P = 0.024]. From 2013 to 2016, there were no significant changes in the emergency response time, prehospital successful resuscitation rate and survival to hospital discharge rate of patients with VF in Shanghai. Though, repeated defibrillation could significantly increased prehospital successful resuscitation rate, multiple defibrillation indicated decline of survival to hospital discharge rate in prehospital successful resuscitation group. Additionally, long on-site time and long ROSC time indicated poor prognosis.

Chest Compressions during Sustained Inflations Improve Recovery When Compared to a 3:1 Compression:Ventilation Ratio during Cardiopulmonary Resuscitation in a Neonatal Porcine Model of Asphyxia

Background: Recently, sustained inflations (SI) during chest compression (CC) (CC+SI) have been suggested as an alternative to the current approach during neonatal resuscitation. No previous study compared CC+SI using CC rates of 90/min to the current 3:1 compression:ventilation ratio (C:V). Objective: To determine whether CC+SI versus a 3:1 C:V reduces the time to the return of spontaneous circulation (ROSC) and improves hemodynamic recovery in newborn piglets with asphyxia-induced bradycardia. Intervention and Measurements: Term newborn piglets were anesthetized, intubated, instrumented, and exposed to 45-min normocapnic hypoxia followed by asphyxia. Cardiopulmonary resuscitation (CPR) was initiated when the heart rate decreased to 25% of baseline. Piglets were randomized into 3 groups: CC during SI at a rate of 90 CC/min (SI+CC 90, n = 8), a 3:1 C:V using 90 CC and 30 inflations (3:1, n = 8), or a sham group (n = 6). Cardiac function, carotid blood flow, cerebral oxygenation, and respiratory parameters were continuously recorded throughout the experiment. Results: CC+SI significantly reduced the median (IQR) time of ROSC, i.e., 34 s (28-156 s) versus 210 s (72-300 s) in the 3:1 group (p = 0.048). CC+SI also significantly reduced the requirement for 100% oxygen, improved respiratory parameters, and resulted in a similar hemodynamic recovery. Conclusions: CC+SI during CPR significantly improved ROSC in a porcine model of neonatal resuscitation. This is of considerable clinical relevance because improved respiratory and hemodynamic parameters potentially minimize morbidity and mortality in newborn infants.

Abstract 12854: Parenchymal Lung Injuries Related to Standard Cardiopulmonary Resuscitation

Purpose: Little is known about parenchymal lung injuries after external chest compressions during cardiopulmonary resuscitation (CPR). We analysed chest CT scan to evaluate parenchymal lung injury and its clinical significance in patients who received standard CPR and were resuscitated from cardiac arrest. Materials and Methods: We enrolled non-traumatic out-of-hospital cardiac arrest patients older than 18 years old who had been admitted to the ED in cardiac arrest and successfully resuscitated after CPR. Chest CT was obtained immediately after return of spontaneous circulation (ROSC). To allocate the area of lung contusion, we divided both hemithoraces into upper, middle, and lower parts longitudinally and each part was subdivided into 4 regions (anteromedial, anterolateral, posteromedial, and posterolateral) except the lower part of the left lung. Finally, both lungs were divided into 23 regions. To stratify the severity of lung contusion, each region was scored depending on the area of lung contusion (ALC) with 1 = ALC&lt;1/3 of a region, 2 = 1/3≤ALC&lt;2/3 of a region and 3=ALC≥2/3 of a region. Oxygenation index (OI: PaO 2 /FiO 2 ) was measured at the time of ROSC, 24hr, 48hr, 72hr, and 1 week after cardiac arrest. Acute lung injury (ALI) was defined as OI below 300. Results: Ninety-one patients were enrolled. Lung contusion was developed in 37 patients (40.7%) and median lung contusion score was 15 (0-15). Lung contusion was not associated with hospital mortality (p=0.318), development of ALI (p=0.515), or the length of ICU stay (p=0.203). The OI at the time of ROSC was lower in patients with lung contusion score &gt; 23 than in patients with lung contusion score≤23 (164±93 vs. 278±122, p=0.008). However, the OI at 24hrs, 72hrs, and 1 week after ROSC was not different between patients with lung contusion score &gt; 23 and patients with lung contusion score≤23 (p=0.240, 0.698, 0.446, and 0.168, respectively) Conclusion: Extensive lung contusion is associated with a lower oxygenation index at the time of ROSC, but did not affect the resuscitation outcome.

Parenchymal lung injuries related to standard cardiopulmonary resuscitation

ObjectivesWe analyzed chest computed tomographic scan to evaluate parenchymal lung injury and its clinical significance in patients who received standard cardiopulmonary resuscitation and were resuscitated from cardiac arrest. MethodsWe enrolled nontraumatic out-of-hospital cardiac arrest patients older than 19 years who had been admitted to the emergency department in cardiac arrest and successfully resuscitated after cardiopulmonary resuscitation. Chest computed tomography was obtained immediately after return of spontaneous circulation (ROSC). To allocate the area of lung contusion, we divided both hemithoraces into 3 regions longitudinally, and each part was subdivided into 4 segments except the lower part of the left lung. To stratify the severity of lung contusion, each segment was scored depending on the area of lung contusion. Oxygen index (OI) was measured at the time of ROSC, 24, 48, and 72 hours and 1 week after cardiac arrest. ResultsLung contusion was developed in 37 (41%) patients and median lung contusion score (LCS) was 17 (12-26). Lung contusion was not associated with hospital mortality (P = .924) or length of intensive care unit stay (P = .446). The OI at the time of ROSC was lower in patients with LCS greater than 23 than that in patients with LCS less than or equal to 23 (126 [93-224] vs 278 [202-367]; P = .008); however, the OI at the other timelines was not different between patients with LCS greater than 23 and patients with LCS less than or equal to 23. ConclusionExtensive lung contusion is associated with a lower oxygenation index at the time of ROSC, but did not affect the resuscitation outcome.