Factors associated with re-arrest following initial resuscitation from cardiac arrest

Trends in Incidence and Outcomes of Cardiac Arrest Occurring in Swedish ICUs

OBJECTIVE

To determine temporal trends in the incidence of cardiac arrest occurring in the ICU (ICU-CA) and its associated long-term mortality.

DESIGN

Retrospective observational study.

SETTING

Swedish ICUs, between 2011 and 2017.

PATIENTS

Adult patients (≥18 yr old) recorded in the Swedish Intensive Care Registry (SIR).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

ICU-CA was defined as a first episode of cardiopulmonary resuscitation and/or defibrillation following an ICU admission, as recorded in SIR or the Swedish Cardiopulmonary Resuscitation Registry. Annual adjusted ICU-CA incidence trend (all admissions) was estimated using propensity score-weighted analysis. Six-month mortality trends (first admissions) were assessed using multivariable mixed-effects logistic regression. Analyses were adjusted for pre-admission characteristics (sex, age, socioeconomic status, comorbidities, medications, and healthcare utilization), illness severity on ICU admission, and admitting unit. We included 231,427 adult ICU admissions. Crude ICU-CA incidence was 16.1 per 1,000 admissions, with no significant annual trend in the propensity score-weighted analysis. Among 186,530 first admissions, crude 6-month mortality in ICU-CA patients was 74.7% (95% CI, 70.1-78.9) in 2011 and 68.8% (95% CI, 64.4-73.0) in 2017. When controlling for multiple potential confounders, the adjusted 6-month mortality odds of ICU-CA patients decreased by 6% per year (95% CI, 2-10). Patients admitted after out-of-hospital or in-hospital cardiac arrest had the highest ICU-CA incidence (136.1/1,000) and subsequent 6-month mortality (76.0% [95% CI, 73.6-78.4]).

CONCLUSIONS

In our nationwide Swedish cohort, the adjusted incidence of ICU-CA remained unchanged between 2011 and 2017. More than two-thirds of patients with ICU-CA did not survive to 6 months following admission, but a slight improvement appears to have occurred over time.

A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study

BACKGROUND

Unsustained return of spontaneous circulation (ROSC) is a critical barrier to survival in cardiac arrest patients. This study examined whether end-tidal carbon dioxide (ETCO2) and pulse oximetry photoplethysmogram (POP) parameters can be used to identify unsustained ROSC.

METHODS

We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to 2014. Patients' general information, ETCO2, and POP parameters were collected and statistically analyzed.

RESULTS

The included 105 ROSC episodes (from 80 cardiac arrest patients) comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes. The 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group (29.2% vs. 9.4%, P<0.05). The logistic regression analysis showed that the difference between after and before ROSC in ETCO2 (ΔETCO2) and the difference between after and before ROCS in area under the curve of POP (ΔAUCp) were independently associated with sustained ROSC (odds ratio [OR]=0.931, 95% confidence interval [95% CI] 0.881-0.984, P=0.011 and OR=0.998, 95% CI 0.997-0.999, P<0.001). The area under the receiver operating characteristic curve of ΔETCO2, ΔAUCp, and the combination of both to predict unsustained ROSC were 0.752 (95% CI 0.660-0.844), 0.883 (95% CI 0.818-0.948), and 0.902 (95% CI 0.842-0.962), respectively.

CONCLUSION

Patients with unsustained ROSC have a poor prognosis. The combination of ΔETCO2 and ΔAUCp showed significant predictive value for unsustained ROSC.

How to predict the death risk after an in-hospital cardiac arrest (IHCA) in intensive care unit? A retrospective double-centre cohort study from a tertiary hospital in China

OBJECTIVES

Our objective is to develop a prediction tool to predict the death after in-hospital cardiac arrest (IHCA).

DESIGN

We conducted a retrospective double-centre observational study of IHCA patients from January 2015 to December 2021. Data including prearrest diagnosis, clinical features of the IHCA and laboratory results after admission were collected and analysed. Logistic regression analysis was used for multivariate analyses to identify the risk factors for death. A nomogram was formulated and internally evaluated by the boot validation and the area under the curve (AUC). Performance of the nomogram was further accessed by Kaplan-Meier survival curves for patients who survived the initial IHCA.

SETTING

Intensive care unit, Tongji Hospital, China.

PARTICIPANTS

Adult patients (≥18 years) with IHCA after admission. Pregnant women, patients with 'do not resuscitation' order and patients treated with extracorporeal membrane oxygenation were excluded.

INTERVENTIONS

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the death after IHCA.

RESULTS

Patients (n=561) were divided into two groups: non-sustained return of spontaneous circulation (ROSC) group (n=241) and sustained ROSC group (n=320). Significant differences were found in sex (p=0.006), cardiopulmonary resuscitation (CPR) duration (p<0.001), total duration of CPR (p=0.014), rearrest (p<0.001) and length of stay (p=0.004) between two groups. Multivariate analysis identified that rearrest, duration of CPR and length of stay were independently associated with death. The nomogram including these three factors was well validated using boot calibration plot and exhibited excellent discriminative ability (AUC 0.88, 95% CI 0.83 to 0.93). The tertiles of patients in sustained ROSC group stratified by anticipated probability of death revealed significantly different survival rate (p<0.001).

CONCLUSIONS

Our proposed nomogram based on these three factors is a simple, robust prediction model to accurately predict the death after IHCA.

Automated aortic endovascular balloon volume titration prevents re-arrest immediately after return of spontaneous circulation in a swine model of nontraumatic cardiac arrest

Objectives

Endovascular aortic occlusion as an adjunct to cardiopulmonary resuscitation (CPR) for non-traumatic cardiac arrest is gaining interest. In a recent clinical trial, return of spontaneous circulation (ROSC) was achieved despite prolonged no-flow times. However, 66% of patients re-arrested upon balloon deflation. We aimed to determine if automated titration of endovascular balloon volume following ROSC can augment diastolic blood pressure (DBP) to prevent re-arrest.

Methods

Twenty swine were anesthetized and placed into ventricular fibrillation (VF). Following 7 minutes of no-flow VF and 5 minutes of mechanical CPR, animals were subjected to complete aortic occlusion to adjunct CPR. Upon ROSC, the balloon was either deflated steadily over 5 minutes (control) or underwent automated, dynamic adjustments to maintain a DBP of 60 mmHg (Endovascular Variable Aortic Control, EVAC).

Results

ROSC was obtained in ten animals (5 EVAC, 5 REBOA). Sixty percent (3/5) of control animals rearrested while none of the EVAC animals rearrested (p = 0.038). Animals in the EVAC group spent a significantly higher proportion of the post-ROSC period with a DBP > 60 mmHg [median (IQR)] [control 79.7 (72.5–86.0)%; EVAC 97.7 (90.8–99.7)%, p = 0.047]. The EVAC group had a statistically significant reduction in arterial lactate concentration [7.98 (7.4–8.16) mmol/L] compared to control [9.93 (8.86–10.45) mmol/L, p = 0.047]. There were no statistical differences between the two groups in the amount of adrenaline (epinephrine) required.

Conclusion

In our swine model of cardiac arrest, automated aortic endovascular balloon titration improved DBP and prevented re-arrest in the first 20 minutes after ROSC.

Rearrest during hospitalisation in adult comatose out-of-hospital cardiac arrest patients: Risk factors and prognostic impact, and predictors of favourable long-term outcomes

BACKGROUND

Rearrest occurs commonly after initial resuscitation following out-of-hospital cardiac arrest (OHCA). We determined (1) the predictors of rearrest during hospitalisation that can be identified in the hours immediately after OHCA, (2) the association between rearrest and favourable long-term outcomes, and (3) the predictors of favourable long-term outcomes in rearrest patients.

METHODS

Conditional multivariable logistic regression analyses were performed using the Korean Hypothermia Network prospective registry data, which included details of adult OHCA patients treated with targeted temperature management at 22 teaching hospitals in South Korea.

RESULTS

Among the 1,233 patients, 260 (21.1%) experienced rearrest. Of the 192 patients resuscitated from first rearrest, 33 (17.2%) achieved 6-month favourable outcomes. Arrhythmia, heart failure, ST-segment elevation, lower initial Glasgow coma scale (GCS) motor score, higher initial lactate level, and antiarrhythmic drug use within 1 h were independently associated with rearrest. Higher lactate level and antiarrhythmic drug use were associated with shockable first rearrest, while arrhythmia, heart failure, ST-segment elevation, and lower GCS motor score were associated with non-shockable first rearrest. Rearrest was independently associated with a lower likelihood of 6-month favourable outcomes (P = 0.003). Initial shockable rhythm after OHCA, absence of diabetes, shorter cumulative time to restoration of spontaneous circulation, coronary angiography, and hypophosphataemia within 7 d were independently associated with 6-month favourable outcomes in the patients resuscitated from first rearrest.

CONCLUSIONS

Rearrest during hospitalisation after OHCA was inversely associated with 6-month favourable outcomes. We identified several risk factors for rearrest and prognostic factors for patients resuscitated from first rearrest.

Postarrest Interventions that Save Lives

Patients resuscitated from cardiac arrest require complex management. An organized approach to early postarrest care can improve patient outcomes. Priorities include completing a focused diagnostic work-up to identify and reverse the inciting cause of arrest, stabilizing cardiorespiratory instability to prevent rearrest, minimizing secondary brain injury, evaluating the risk and benefits of transfer to a specialty care center, and avoiding early neurologic prognostication.

Towards the Prediction of Rearrest during Out-of-Hospital Cardiac Arrest

A secondary arrest is frequent in patients that recover spontaneous circulation after an out-of-hospital cardiac arrest (OHCA). Rearrest events are associated to worse patient outcomes, but little is known on the heart dynamics that lead to rearrest. The prediction of rearrest could help improve OHCA patient outcomes. The aim of this study was to develop a machine learning model to predict rearrest. A random forest classifier based on 21 heart rate variability (HRV) and electrocardiogram (ECG) features was designed. An analysis interval of 2 min after recovery of spontaneous circulation was used to compute the features. The model was trained and tested using a repeated cross-validation procedure, on a cohort of 162 OHCA patients (55 with rearrest). The median (interquartile range) sensitivity (rearrest) and specificity (no-rearrest) of the model were 67.3% (9.1%) and 67.3% (10.3%), respectively, with median areas under the receiver operating characteristics and the precision–recall curves of 0.69 and 0.53, respectively. This is the first machine learning model to predict rearrest, and would provide clinically valuable information to the clinician in an automated way.

Renal replacement therapy is independently associated with a lower risk of death in patients with severe acute kidney injury treated with targeted temperature management after out-of-hospital cardiac arrest

BACKGROUND

The effect of renal replacement therapy (RRT) on the outcomes of severe acute kidney injury (AKI) after out-of-hospital cardiac arrest (OHCA) is uncertain. This study aimed to evaluate the association of RRT with 6-month mortality in patients with severe AKI treated with targeted temperature management (TTM) after OHCA.

METHODS

This was a retrospective analysis of a prospectively collected multicentre observational cohort study that included adult OHCA patients treated with TTM across 22 hospitals in South Korea between October 2015 and December 2018. AKI was diagnosed using the Kidney Disease: Improving Global Outcomes criteria. The primary outcome was 6-month mortality and the secondary outcome was cerebral performance category (CPC) at 6 months. Multivariate Cox regression analysis was performed to define the role of RRT in stage 3 AKI.

RESULTS

Among 10,426 patients with OHCA, 1373 were treated with TTM. After excluding those who died within 48 h of return of spontaneous circulation (ROSC) and those with pre-arrest chronic kidney disease, our study cohort comprised 1063 patients. AKI developed in 590 (55.5%) patients and 223 (21.0%) had stage 3 AKI. Among them, 115 (51.6%) were treated with RRT. The most common treatment modality among RRT patients was continuous renal replacement therapy (111 [96.5%]), followed by intermittent haemodialysis (4 [3.5%]). The distributions of CPC (1-5) at 6 months for the non-RRT vs. the RRT group were 3/108 (2.8%) vs. 12/115 (10.4%) for CPC 1, 0/108 (0.0%) vs. 1/115 (0.9%) for CPC 2, 1/108 (0.9%) vs. 3/115 (2.6%) for CPC 3, 6/108 (5.6%) vs. 6/115 (5.2%) for CPC 4, and 98/108 (90.7%) vs. 93/115 (80.9%) for CPC 5, respectively (P = 0.01). The RRT group had significantly lower 6-month mortality than the non-RRT group (93/115 [81%] vs. 98/108 [91%], P = 0.04). Multivariate Cox regression analyses showed that RRT was independently associated with a lower risk of death in patients with stage 3 AKI (hazard ratio, 0.569 [95% confidence interval, 0.377-0.857, P = 0.01]).

CONCLUSION

Dialysis interventions were independently associated with a lower risk of death in patients with stage 3 AKI treated with TTM after OHCA.

Survival and Rearrest in out-of-Hospital Cardiac Arrest Patients with Prehospital Return of Spontaneous Circulation: A Prospective Multi-Regional Observational Study

OBJECTIVE

We aimed to determine the factors associated with rearrest after prehospital return of spontaneous circulation (ROSC) and examine the factors associated with survival despite rearrest.

METHODS

We conducted a prospective multi-regional observational study of out-of-hospital cardiac arrest (OHCA) patients between August 2015 and July 2016. Patients received prehospital advanced cardiovascular life support performed by emergency medical technicians (EMTs). EMTs were directly supervised by medical directors (physicians) via real-time smartphone video calls [Smart Advanced Life Support (SALS)]. The study participants were categorized into rearrest (+) and rearrest (-) groups depending on whether rearrest occurred after prehospital ROSC. After rearrest, patients were further classified as survivors or non-survivors at discharge.

RESULTS

SALS was performed in 1,711 OHCA patients. Prehospital ROSC occurred in 345 patients (20.2%); of these patients, 189 (54.8%) experienced rearrest [rearrest (+) group] and 156 did not experience rearrest [rearrest (-) group]. Multivariate analysis showed that a longer interval from collapse to first prehospital ROSC was independently associated with rearrest [odds ratio (OR) 1.081; 95% confidence interval (CI) 1.050-1.114]. The presence of an initial shockable rhythm was independently associated with survival after rearrest (OR 6.920; 95% CI 2.749-17.422). As a predictor of rearrest, the interval from collapse to first prehospital ROSC (cut-off: 24 min) had a sensitivity of 77% and a specificity of 54% (AUC = 0.715 [95% CI 0.661-0.769]).

CONCLUSIONS

A longer interval from collapse to first prehospital ROSC was associated with rearrest, and an initial shockable rhythm was associated with survival despite the occurrence of rearrest. Emergency medical service providers and physicians should be prepared to deal with rearrest when pulses are obtained late in the resuscitation.

Prognostic Factors for Re-Arrest with Shockable Rhythm during Target Temperature Management in Out-Of-Hospital Shockable Cardiac Arrest Patients

Re-arrest during post-cardiac arrest care after the return of spontaneous circulation is not uncommon. However, little is known about the risk factors associated with re-arrest. A previous study failed to show a benefit of prophylactic antiarrhythmic drug infusion in all kinds of out-of-hospital cardiac arrest (OHCA) survivors. This study evaluated high-risk OHCA survivors who may have re-arrest with shockable rhythm during targeted temperature management (TTM). Medical records of consecutive OHCA survivors treated with TTM at four tertiary referral university hospitals in the Republic of Korea between January 2010 and December 2016 were retrospectively reviewed. Patients who did not have any shockable rhythm during cardiopulmonary resuscitation (CPR) or unknown initial rhythm were excluded. The primary outcome of interest was the recurrence of shockable cardiac arrest during TTM. There were 289 cases of initial shockable arrest rhythm and 132 cases of shockable rhythm during CPR. Of the 421 included patients, 11.4% of patients had a shockable re-arrest during TTM. Survival to discharge and good neurologic outcomes did not differ between non-shockable and shockable re-arrest patients (78.3% vs. 72.9%, p = 0.401; 53.1% vs. 54.2% p = 0.887). Initial serum magnesium level, ST segment depression or ventricular premature complex (VPC) in initial electrocardiography (ECG), prophylactic amiodarone infusion, and dopamine and norepinephrine infusion during TTM were significantly higher and more frequent in the shockable re-arrest group (all p values < 0.05). Normal ST and T wave in initial ECG was common in the non-shockable re-arrest group (p = 0.038). However, in multivariate logistic regression analysis, only VPC was an independent prognostic factor for shockable re-arrest (OR 2.806 (95% CI 1.276-6.171), p = 0.010). Initial VPC may be a prognostic risk factor for shockable re-arrest in OHCA survivors with shockable rhythm.

The effect of extracorporeal cardiopulmonary resuscitation in re-arrest after survival event: a retrospective analysis

BACKGROUND

The objectives of this study were to 1) identify the risk factors for predicting re-arrest and 2) determine whether extracorporeal cardiopulmonary resuscitation results in better outcomes than conventional cardiopulmonary resuscitation for managing re-arrest in out-of-hospital cardiac arrest patients.

METHODS

This retrospective analysis was based on a prospective cohort. We included adult patients with non-traumatic out-of-hospital cardiac arrest who achieved a survival event. The primary measurement was re-arrest, defined as recurrent cardiac arrest within 24 hours after survival event. Multiple logistic regression analysis was used to predict re-arrest. Subgroup analysis was performed to evaluate the effect of extracorporeal cardiopulmonary resuscitation on the survival to discharge in out-of-hospital cardiac arrest patients who experienced re-arrest.

RESULTS

Of 534 patients suitable for inclusion, 203 (38.0%) were enrolled in the re-arrest group. Old age, prolonged advanced cardiac life support duration and the presence of hypotension at 0 hours after survival event were independent variables predicting re-arrest. In the re-arrest group, the extracorporeal cardiopulmonary resuscitation group (n = 25) showed better outcomes than the conventional cardiopulmonary resuscitation group. However, multiple logistic regression for predicting survival to discharge revealed that extracorporeal cardiopulmonary resuscitation was not an independent factor. Multiple logistic regression revealed that a hypotensive state at re-arrest was an independent risk factor for survival.

CONCLUSION

Alternative methods that reduce the advanced cardiac life support duration should be considered to prevent re-arrest and attain good outcomes in out-of-hospital cardiac arrest patients. Extracorporeal cardiopulmonary resuscitation for re-arrest tended to show a good outcome compared to conventional cardiopulmonary resuscitation for re-arrest. Avoiding or immediately correcting hypotension may prevent re-arrest and improve the outcome of re-arrested patients.

Use of amplitude-integrated electroencephalography in decision-making for extracorporeal membrane oxygenation in comatose cardiac arrest patients whose eventual neurologic recovery is uncertain

Comatose cardiac arrest patients frequently experience cardiogenic shock or recurrent arrest. Extracorporeal membrane oxygenation (ECMO) can be used to salvage patients with cardiogenic shock or cardiac arrest refractory to conventional therapies. However, in comatose cardiac arrest patients whose neurologic recovery is uncertain, the use of ECMO is restricted because it requires considerable financial and human resources. Amplitude-integrated electroencephalography is an easily applicable, real-time electroencephalography monitoring tool that has been increasingly used to monitor brain activity in comatose cardiac arrest patients. We describe our experience of using amplitude-integrated electroencephalography in decision-making to place ECMO for comatose cardiac arrest patients whose eventual neurologic recovery appeared uncertain at the time of ECMO placement.

Factors associated with the decision to terminate resuscitation early for adult in-hospital cardiac arrest: Influence of family in an East Asian society

Background

We attempted to identify factors associated with physicians’ decisions to terminate CPR and to explore the role of family in the decision-making process.

Methods

We conducted a retrospective observational study in a single center in Taiwan. Patients who experienced in-hospital cardiac arrest (IHCA) between 2006 and 2014 were screened for study inclusion. Multivariate survival analysis was conducted to identify independent variables associated with IHCA outcomes using the Cox proportional hazards model.

Results

A total of 1525 patients were included in the study. Family was present at the beginning of CPR during 722 (47.3%) resuscitation events. The median CPR duration was significantly shorter for patients with family present at the beginning of CPR than for those without family present (23.5 mins vs 30 min, p = 0.01). Some factors were associated with shorter time to termination of CPR, including arrest in an intensive care unit, Charlson comorbidity index score greater than 2, age older than 79 years, baseline evidence of motor, cognitive, or functional deficits, and vasopressors in place at time of arrest. After adjusting for confounding effects, family presence was associated with shorter time to termination of CPR (hazard ratio, 1.25; 95% confidence interval, 1.06–1.46; p = 0.008).

Conclusion

Clinicians’ decisions concerning when to terminate CPR seemed to be based on outcome prognosticators. Family presence at the beginning of CPR was associated with shorter duration of CPR. Effective communication, along with outcome prediction tools, may avoid prolonged CPR efforts in an East Asian society.

Cardiomyocyte lethality by multidirectional stimuli

Multidirectional defibrillation protocols have shown better efficiency than monodirectional; still, no testing was performed to assess cell lethality. We investigated lethality of multidirectional defibrillator-like shocks on isolated cardiomyocytes. Cells were isolated from adult male Wistar rats and plated into a perfusion chamber. Electrical field stimulation threshold (E_T) was obtained, and cells were paced with suprathreshold bipolar electrical field (E) pulses. Either one monodirectional high-intensity electrical field (HEF) pulse aligned at 0° (group Mono0) or 60° (group Mono60) to cell major axis or a multidirectional sequence of three HEF pulses aligned at 0°, 60°, and 120° each was applied. If cell recovered from shock, pacing was resumed, and a higher amplitude HEF, proportional to E_T, was applied. The sequence was repeated until cell death. Lethality curves were built by means of survival analysis from sub-lethal and lethal E. Non-linear fit was performed, and E values corresponding to 50% probability of lethality (E50) were compared. Multidirectional groups presented lethality curves similar to Mono0. Mono60 displayed the highest E50. The novel data endorse the idea of multidirectional stimuli being safer because their effects on lethality of individual cells were equal to a single monodirectional stimulus, while their defibrillatory threshold is lower. Graphical abstract Monodirectional and multidirectional lethality protocol comparison on isolated rat cardiomyocytes. The heart image is a derivative of "3D Heart in zBrush" ( https://vimeo.com/65568770 ) by Laloxl, used under CC BY 3.0 ( https://creativecommons.org/licenses/by/3.0/legalcode )/image extracted from original video.