Pulmonary Vasodilator Therapy in Shock-associated Cardiac Arrest

Wolf Creek XVII part 9: Wolf Creek Innovator in Cardiac Arrest and Resuscitation Science Award

The Wolf Creek Conferences on Cardiac Arrest Resuscitation began in 1975, and have served as an important forum for thought leaders and scientists from industry and academia to come together with the common goal of advancing the field of cardiac arrest resuscitation. The Wolf Creek XVII Conference was hosted by the Max Harry Weil Institute of Critical Care Research and Innovation in Ann Arbor, Michigan on June 14-17, 2023. A new component of the conference was the Wolf Creek Innovator in Cardiac Arrest and Resuscitation Science Award competition. The competition was designed to recognize early career investigators from around the world who's science is challenging the current paradigms in the field. Finalists were selected by a panel of international experts and invited to present in-person at the conference. The winner was chosen by electronic vote of conference participants and awarded a $10,0000 cash prize. Finalists included Carolina Barbosa Maciel from the University of Florida, Adam Gottula from the University of Michigan, Rajat Kalra from the University of Minnesota, Ryan Morgan from the Children's Hospital of Philadelphia, Mitsuaki Nishikimi form Hiroshima University, and Jacob Sunshine from the University of Washington. Ryan Morgan from the Children's Hospital of Philadelphia was selected as the 2023 Wolf Creek Innovator Awardee. This manuscript provides a summary of the work presented by each of the finalists and provides a preview of the future of resuscitation science.

Outcomes and characteristics of cardiac arrest in children with pulmonary hypertension: A secondary analysis of the ICU-RESUS clinical trial

BACKGROUND

Previous studies have identified pulmonary hypertension (PH) as a relatively common diagnosis in children with in-hospital cardiac arrest (IHCA), and preclinical laboratory studies have found poor outcomes and low systemic blood pressures during CPR for PH-associated cardiac arrest. The objective of this study was to determine the prevalence of PH among children with IHCA and the association between PH diagnosis and intra-arrest physiology and survival outcomes.

METHODS

This was a prospectively designed secondary analysis of patients enrolled in the ICU-RESUS clinical trial (NCT02837497). The primary exposure was a pre-arrest diagnosis of PH. The primary survival outcome was survival to hospital discharge with favorable neurologic outcome (Pediatric Cerebral Performance Category score 1-3 or unchanged from baseline). The primary physiologic outcome was event-level average diastolic blood pressure (DBP) during CPR.

RESULTS

Of 1276 patients with IHCAs during the study period, 1129 index IHCAs were enrolled; 184 (16.3%) had PH and 101/184 (54.9%) were receiving inhaled nitric oxide at the time of IHCA. Survival with favorable neurologic outcome was similar between patients with and without PH on univariate (48.9% vs. 54.4%; p = 0.17) and multivariate analyses (aOR 0.82 [95%CI: 0.56, 1.20]; p = 0.32). There were no significant differences in CPR event outcome or survival to hospital discharge. Average DBP, systolic BP, and end-tidal carbon dioxide during CPR were similar between groups.

CONCLUSIONS

In this prospective study of pediatric IHCA, pre-existing PH was present in 16% of children. Pre-arrest PH diagnosis was not associated with statistically significant differences in survival outcomes or intra-arrest physiologic measures.

The physiologic response to epinephrine and pediatric cardiopulmonary resuscitation outcomes

BACKGROUND

Epinephrine is provided during cardiopulmonary resuscitation (CPR) to increase systemic vascular resistance and generate higher diastolic blood pressure (DBP) to improve coronary perfusion and attain return of spontaneous circulation (ROSC). The DBP response to epinephrine during pediatric CPR and its association with outcomes have not been well described. Thus, the objective of this study was to measure the association between change in DBP after epinephrine administration during CPR and ROSC.

METHODS

This was a prospective multicenter study of children receiving ≥ 1 min of CPR with ≥ 1 dose of epinephrine and evaluable invasive arterial BP data in the 18 ICUs of the ICU-RESUS trial (NCT02837497). Blood pressure waveforms underwent compression-by-compression quantitative analysis. The mean DBP before first epinephrine dose was compared to mean DBP two minutes post-epinephrine. Patients with ≥ 5 mmHg increase in DBP were characterized as "responders."

RESULTS

Among 147 patients meeting inclusion criteria, 66 (45%) were characterized as responders and 81 (55%) were non-responders. The mean increase in DBP with epinephrine was 4.4 [- 1.9, 11.5] mmHg (responders: 13.6 [7.5, 29.3] mmHg versus non-responders: - 1.5 [- 5.0, 1.5] mmHg; p < 0.001). After controlling for a priori selected covariates, epinephrine response was associated with ROSC (aRR 1.60 [1.21, 2.12]; p = 0.001). Sensitivity analyses identified similar associations between DBP response thresholds of ≥ 10, 15, and 20 mmHg and ROSC; DBP responses of ≥ 10 and ≥ 15 mmHg were associated with higher aRR of survival to hospital discharge and survival with favorable neurologic outcome (Pediatric Cerebral Performance Category score of 1-3 or no worsening from baseline).

CONCLUSIONS

The change in DBP following epinephrine administration during pediatric in-hospital CPR was associated with return of spontaneous circulation.

Diastolic Blood Pressure Threshold During Pediatric Cardiopulmonary Resuscitation and Survival Outcomes: A Multicenter Validation Study

OBJECTIVES

Arterial diastolic blood pressure (DBP) greater than 25 mm Hg in infants and greater than 30 mm Hg in children greater than 1 year old during cardiopulmonary resuscitation (CPR) was associated with survival to hospital discharge in one prospective study. We sought to validate these potential hemodynamic targets in a larger multicenter cohort.

DESIGN

Prospective observational study.

SETTING

Eighteen PICUs in the ICU-RESUScitation prospective trial from October 2016 to March 2020.

PATIENTS

Children less than or equal to 18 years old with CPR greater than 30 seconds and invasive blood pressure (BP) monitoring during CPR.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Invasive BP waveform data and Utstein-style CPR data were collected, including prearrest patient characteristics, intra-arrest interventions, and outcomes. Primary outcome was survival to hospital discharge, and secondary outcomes were return of spontaneous circulation (ROSC) and survival to hospital discharge with favorable neurologic outcome. Multivariable Poisson regression models with robust error estimates evaluated the association of DBP greater than 25 mm Hg in infants and greater than 30 mm Hg in older children with these outcomes. Among 1,129 children with inhospital cardiac arrests, 413 had evaluable DBP data. Overall, 85.5% of the patients attained thresholds of mean DBP greater than or equal to 25 mm Hg in infants and greater than or equal to 30 mm Hg in older children. Initial return of circulation occurred in 91.5% and 25% by placement on extracorporeal membrane oxygenator. Survival to hospital discharge occurred in 58.6%, and survival with favorable neurologic outcome in 55.4% (i.e. 94.6% of survivors had favorable neurologic outcomes). Mean DBP greater than 25 mm Hg for infants and greater than 30 mm Hg for older children was significantly associated with survival to discharge (adjusted relative risk [aRR], 1.32; 1.01-1.74; p = 0.03) and ROSC (aRR, 1.49; 1.12-1.97; p = 0.002) but did not reach significance for survival to hospital discharge with favorable neurologic outcome (aRR, 1.30; 0.98-1.72; p = 0.051).

CONCLUSIONS

These validation data demonstrate that achieving mean DBP during CPR greater than 25 mm Hg for infants and greater than 30 mm Hg for older children is associated with higher rates of survival to hospital discharge, providing potential targets for DBP during CPR.

Nitric oxide: Clinical applications in critically ill patients

Inhaled nitric oxide (iNO) acts as a selective pulmonary vasodilator and it is currently approved by the FDA for the treatment of persistent pulmonary hypertension of the newborn. iNO has been demonstrated to effectively decrease pulmonary artery pressure and improve oxygenation, while decreasing extracorporeal life support use in hypoxic newborns affected by persistent pulmonary hypertension. Also, iNO seems a safe treatment with limited side effects. Despite the promising beneficial effects of NO in the preclinical literature, there is still a lack of high quality evidence for the use of iNO in clinical settings. A variety of clinical applications have been suggested in and out of the critical care environment, aiming to use iNO in respiratory failure and pulmonary hypertension of adults or as a preventative measure of hemolysis-induced vasoconstriction, ischemia/reperfusion injury and as a potential treatment of renal failure associated with cardiopulmonary bypass. In this narrative review we aim to present a comprehensive summary of the potential use of iNO in several clinical conditions with its suggested benefits, including its recent application in the scenario of the COVID-19 pandemic. Randomized controlled trials, meta-analyses, guidelines, observational studies and case-series were reported and the main findings summarized. Furthermore, we will describe the toxicity profile of NO and discuss an innovative proposed strategy to produce iNO. Overall, iNO exhibits a wide range of potential clinical benefits, that certainly warrants further efforts with randomized clinical trials to determine specific therapeutic roles of iNO.

Effect of Physiologic Point-of-Care Cardiopulmonary Resuscitation Training on Survival With Favorable Neurologic Outcome in Cardiac Arrest in Pediatric ICUs: A Randomized Clinical Trial

IMPORTANCE

Approximately 40% of children who experience an in-hospital cardiac arrest survive to hospital discharge. Achieving threshold intra-arrest diastolic blood pressure (BP) targets during cardiopulmonary resuscitation (CPR) and systolic BP targets after the return of circulation may be associated with improved outcomes.

OBJECTIVE

To evaluate the effectiveness of a bundled intervention comprising physiologically focused CPR training at the point of care and structured clinical event debriefings.

DESIGN, SETTING, AND PARTICIPANTS

A parallel, hybrid stepped-wedge, cluster randomized trial (Improving Outcomes from Pediatric Cardiac Arrest-the ICU-Resuscitation Project [ICU-RESUS]) involving 18 pediatric intensive care units (ICUs) from 10 clinical sites in the US. In this hybrid trial, 2 clinical sites were randomized to remain in the intervention group and 2 in the control group for the duration of the study, and 6 were randomized to transition from the control condition to the intervention in a stepped-wedge fashion. The index (first) CPR events of 1129 pediatric ICU patients were included between October 1, 2016, and March 31, 2021, and were followed up to hospital discharge (final follow-up was April 30, 2021).

INTERVENTION

During the intervention period (n = 526 patients), a 2-part ICU resuscitation quality improvement bundle was implemented, consisting of CPR training at the point of care on a manikin (48 trainings/unit per month) and structured physiologically focused debriefings of cardiac arrest events (1 debriefing/unit per month). The control period (n = 548 patients) consisted of usual pediatric ICU management of cardiac arrest.

MAIN OUTCOMES AND MEASURES

The primary outcome was survival to hospital discharge with a favorable neurologic outcome defined as a Pediatric Cerebral Performance Category score of 1 to 3 or no change from baseline (score range, 1 [normal] to 6 [brain death or death]). The secondary outcome was survival to hospital discharge.

RESULTS

Among 1389 cardiac arrests experienced by 1276 patients, 1129 index CPR events (median patient age, 0.6 [IQR, 0.2-3.8] years; 499 girls [44%]) were included and 1074 were analyzed in the primary analysis. There was no significant difference in the primary outcome of survival to hospital discharge with favorable neurologic outcomes in the intervention group (53.8%) vs control (52.4%); risk difference (RD), 3.2% (95% CI, -4.6% to 11.4%); adjusted OR, 1.08 (95% CI, 0.76 to 1.53). There was also no significant difference in survival to hospital discharge in the intervention group (58.0%) vs control group (56.8%); RD, 1.6% (95% CI, -6.2% to 9.7%); adjusted OR, 1.03 (95% CI, 0.73 to 1.47).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial conducted in 18 pediatric intensive care units, a bundled intervention of cardiopulmonary resuscitation training at the point of care and physiologically focused structured debriefing, compared with usual care, did not significantly improve patient survival to hospital discharge with favorable neurologic outcome among pediatric patients who experienced cardiac arrest in the ICU.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02837497.

Pulmonary hypertension among children with in-hospital cardiac arrest: A multicenter study

AIMS

To determine the prevalence of pulmonary hypertension (PH) among children with in-hospital cardiac arrest (IHCA) and its association with survival.

METHODS

Children (<18 years) admitted to ICUs participating in the Virtual Pediatric Systems multicenter registry between January 2011 and December 2017 who had an IHCA during their hospitalization were included. Patients were classified by whether they had a documented diagnosis of PH at the time of IHCA. Clinical characteristics were compared between patients with and without PH. After propensity score matching, conditional logistic regression within the matched cohort determined the association between PH and survival to hospital discharge.

RESULTS

Of 18,575 children with IHCA during the study period, 1,590 (8.6%) had a pre-arrest diagnosis of PH. Patients with PH were more likely to be 29 days to 2 years of age, female, Black/African American, and American Indian/Alaskan Native, and to be treated in a cardiac ICU or mixed PICU/cardiac ICU. At ICU admission, PH patients had a lower probability of death as determined by the Pediatric Index of Mortality 2 (PIM-2) score. Patients with PH were more likely to be receiving inhaled nitric oxide (13.0% vs. 2.1%; p < 0.001). Propensity score matching successfully matched 1,302 PH patients with 3,604 non-PH patients. Patients with PH were less likely to survive to hospital discharge (aOR 0.83; 95% CI: 0.72-0.95; p = 0.01) than non-PH patients.

CONCLUSIONS

In this large multicenter study, 8.6% of children with IHCA had pre-existing documented PH. These children were less likely to survive to hospital discharge than those without PH.

Nitric oxide delivery using nitric oxide-containing fluid in continuous hemofiltration: an in vitro study

Administering nitrite has therapeutic effects on ischemic conditions wherein the enzymatic production of nitric oxide depends on oxygen. We developed a supplemental fluid containing nitric oxide (NO) and determined the clearance and supply between the pre- and post-dilution modes of continuous hemofiltration in vitro. Nitric oxide gas, 1000 mL or 2000 mL, at a concentration of 1000 ppm, was injected into 2020 mL of conventional supplemental fluid (experimental solution). The same volume of nitrogen gas was injected into the supplemental fluid (control solution). NO concentrations were measured using commercially available NO assay kit. Pre- or post-dilution continuous hemofiltration was performed using a control solution as supplemental fluid to determine the NO clearance. We determined the NO concentration of the outlet blood circuit to confirm the NO supply using the experimental solution as supplemental fluid. Also, using the bovine blood, white blood cell and platelet change rates and the dialysis membrane water flux during continuous hemodiafiltration were evaluated ex vivo as index of the biocompatibilities of a nitric oxide-containing solution. NO was not detected in the control solutions. The experimental solutions significantly increased in nitric oxide concentrations. NO clearance increased as the increase in supplemental and ultrafiltration flow rates using the control solution as supplemental fluid. However, using the experimental solution as supplemental fluid, nitric oxide supply showed a similar trend of NO clearance. Without any changes in biocompatibility using the supplemental fluid containing NO, it could maintain intravascular nitric oxide during continuous renal replacement therapy.

A randomized and blinded trial of inhaled nitric oxide in a piglet model of pediatric cardiopulmonary resuscitation

AIM

Inhaled nitric oxide (iNO) during cardiopulmonary resuscitation (CPR) improved systemic hemodynamics and outcomes in a preclinical model of adult in-hospital cardiac arrest (IHCA) and may also have a neuroprotective role following cardiac arrest. The primary objectives of this study were to determine if iNO during CPR would improve cerebral hemodynamics and mitochondrial function in a pediatric model of lipopolysaccharide-induced shock-associated IHCA.

METHODS

After lipopolysaccharide infusion and ventricular fibrillation induction, 20 1-month-old piglets received hemodynamic-directed CPR and were randomized to blinded treatment with or without iNO (80 ppm) during and after CPR. Defibrillation attempts began at 10 min with a 20-min maximum CPR duration. Cerebral tissue from animals surviving 1-h post-arrest underwent high-resolution respirometry to evaluate the mitochondrial electron transport system and immunohistochemical analyses to assess neuropathology.

RESULTS

During CPR, the iNO group had higher mean aortic pressure (41.6 ± 2.0 vs. 36.0 ± 1.4 mmHg; p = 0.005); diastolic BP (32.4 ± 2.4 vs. 27.1 ± 1.7 mmHg; p = 0.03); cerebral perfusion pressure (25.0 ± 2.6 vs. 19.1 ± 1.8 mmHg; p = 0.02); and cerebral blood flow relative to baseline (rCBF: 243.2 ± 54.1 vs. 115.5 ± 37.2%; p = 0.02). Among the 8/10 survivors in each group, the iNO group had higher mitochondrial Complex I oxidative phosphorylation in the cerebral cortex (3.60 [3.56, 3.99] vs. 3.23 [2.44, 3.46] pmol O₂/s mg; p = 0.01) and hippocampus (4.79 [4.35, 5.18] vs. 3.17 [2.75, 4.58] pmol O₂/s mg; p = 0.02). There were no other differences in mitochondrial respiration or brain injury between groups.

CONCLUSIONS

Treatment with iNO during CPR resulted in superior systemic hemodynamics, rCBF, and cerebral mitochondrial Complex I respiration in this pediatric cardiac arrest model.

Inhaled Gases as Therapies for Post-Cardiac Arrest Syndrome: A Narrative Review of Recent Developments

Despite recent advances in the management of post-cardiac arrest syndrome (PCAS), the survival rate, without neurologic sequelae after resuscitation, remains very low. Whole-body ischemia, followed by reperfusion after cardiac arrest (CA), contributes to PCAS, for which established pharmaceutical interventions are still lacking. It has been shown that a number of different processes can ultimately lead to neuronal injury and cell death in the pathology of PCAS, including vasoconstriction, protein modification, impaired mitochondrial respiration, cell death signaling, inflammation, and excessive oxidative stress. Recently, the pathophysiological effects of inhaled gases including nitric oxide (NO), molecular hydrogen (H₂), and xenon (Xe) have attracted much attention. Herein, we summarize recent literature on the application of NO, H₂, and Xe for treating PCAS. Recent basic and clinical research has shown that these gases have cytoprotective effects against PCAS. Nevertheless, there are likely differences in the mechanisms by which these gases modulate reperfusion injury after CA. Further preclinical and clinical studies examining the combinations of standard post-CA care and inhaled gas treatment to prevent ischemia-reperfusion injury are warranted to improve outcomes in patients who are being failed by our current therapies.

Nitric Oxide in Post-cardiac Arrest Syndrome

Sudden cardiac arrest is a leading cause of death worldwide. Although the methods of cardiopulmonary resuscitation have been improved, mortality is still unacceptably high, and many survivors suffer from lasting neurological deficits due to the post-cardiac arrest syndrome (PCAS). Pathophysiologically, generalized vascular endothelial dysfunction accompanied by platelet activation and systemic inflammation has been implicated in the pathogenesis of PCAS. Because endothelial-derived nitric oxide (NO) plays a central role in maintaining vascular homeostasis, the role of NO-dependent signaling has been a focus of the intense investigation. Recent preclinical studies showed that therapeutic interventions that increase vascular NO bioavailability may improve outcomes after cardiac arrest complicated with PCAS. In particular, NO inhalation therapy has been shown to improve neurological outcomes and survival in multiple species. Clinical studies examining the safety and efficacy of inhaled NO in patients sustaining PCAS are warranted.

The physiologic response to rescue therapy with vasopressin versus epinephrine during experimental pediatric cardiac arrest

Aim

Compare vasopressin to a second dose of epinephrine as rescue therapy after ineffective initial doses of epinephrine in diverse models of pediatric in-hospital cardiac arrest.

Methods

67 one- to three-month old female swine (10−30 kg) in six experimental cohorts from one laboratory received hemodynamic-directed CPR, a resuscitation method where high quality chest compressions are provided and vasopressor administration is titrated to coronary perfusion pressure (CoPP) ≥20 mmHg. Vasopressors are given when CoPP is <20 mmHg, in sequences of two doses of 0.02 mg/kg epinephrine separated by minimum one-minute, then a rescue dose of 0.4 U/kg vasopressin followed by minimum two-minutes. Invasive measurements were used to evaluate and compare the hemodynamic and neurologic effects of each vasopressor dose.

Results

Increases in CoPP and cerebral blood flow (CBF) were greater with vasopressin rescue than epinephrine rescue (CoPP: +8.16 [4.35, 12.06] mmHg vs. + 5.43 [1.56, 9.82] mmHg, p = 0.02; CBF: +14.58 [-0.05, 38.12] vs. + 0.00 [-0.77, 18.24] perfusion units (PFU), p = 0.005). Twenty animals (30%) failed to achieve CoPP ≥20 mmHg after two doses of epinephrine; 9/20 (45%) non-responders achieved CoPP ≥20 mmHg after vasopressin. Among all animals, the increase in CBF was greater with vasopressin (+14.58 [-0.58, 38.12] vs. 0.00 [-0.77, 18.24] PFU, p = 0.005).

Conclusions

CoPP and CBF rose significantly more after rescue vasopressin than after rescue epinephrine. Importantly, CBF increased after vasopressin rescue, but not after epinephrine rescue. In the 30% that failed to meet CoPP of 20 mmHg after two doses of epinephrine, 45% achieved target CoPP with a single rescue vasopressin dose.

Epinephrine's effects on cerebrovascular and systemic hemodynamics during cardiopulmonary resuscitation

BACKGROUND

Despite controversies, epinephrine remains a mainstay of cardiopulmonary resuscitation (CPR). Recent animal studies have suggested that epinephrine may decrease cerebral blood flow (CBF) and cerebral oxygenation, possibly potentiating neurological injury during CPR. We investigated the cerebrovascular effects of intravenous epinephrine in a swine model of pediatric in-hospital cardiac arrest. The primary objectives of this study were to determine if (1) epinephrine doses have a significant acute effect on CBF and cerebral tissue oxygenation during CPR and (2) if the effect of each subsequent dose of epinephrine differs significantly from that of the first.

METHODS

One-month-old piglets (n = 20) underwent asphyxia for 7 min, ventricular fibrillation, and CPR for 10-20 min. Epinephrine (20 mcg/kg) was administered at 2, 6, 10, 14, and 18 min of CPR. Invasive (laser Doppler, brain tissue oxygen tension [PbtO₂]) and noninvasive (diffuse correlation spectroscopy and diffuse optical spectroscopy) measurements of CBF and cerebral tissue oxygenation were simultaneously recorded. Effects of subsequent epinephrine doses were compared to the first.

RESULTS

With the first epinephrine dose during CPR, CBF and cerebral tissue oxygenation increased by > 10%, as measured by each of the invasive and noninvasive measures (p < 0.001). The effects of epinephrine on CBF and cerebral tissue oxygenation decreased with subsequent doses. By the fifth dose of epinephrine, there were no demonstrable increases in CBF of cerebral tissue oxygenation. Invasive and noninvasive CBF measurements were highly correlated during asphyxia (slope effect 1.3, p < 0.001) and CPR (slope effect 0.20, p < 0.001).

CONCLUSIONS

This model suggests that epinephrine increases CBF and cerebral tissue oxygenation, but that effects wane following the third dose. Noninvasive measurements of neurological health parameters hold promise for developing and directing resuscitation strategies.

Ventilation Rates and Pediatric In-Hospital Cardiac Arrest Survival Outcomes

OBJECTIVES

The objective of this study was to associate ventilation rates during in-hospital cardiopulmonary resuscitation with 1) arterial blood pressure during cardiopulmonary resuscitation and 2) survival outcomes.

DESIGN

Prospective, multicenter observational study.

SETTING

Pediatric and pediatric cardiac ICUs of the Collaborative Pediatric Critical Care Research Network.

PATIENTS

Intubated children (≥ 37 wk gestation and < 19 yr old) who received at least 1 minute of cardiopulmonary resuscitation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Arterial blood pressure and ventilation rate (breaths/min) were manually extracted from arterial line and capnogram waveforms. Guideline rate was defined as 10 ± 2 breaths/min; high ventilation rate as greater than or equal to 30 breaths/min in children less than 1 year old, and greater than or equal to 25 breaths/min in older children. The primary outcome was survival to hospital discharge. Regression models using Firth penalized likelihood assessed the association between ventilation rates and outcomes. Ventilation rates were available for 52 events (47 patients). More than half of patients (30/47; 64%) were less than 1 year old. Eighteen patients (38%) survived to discharge. Median event-level average ventilation rate was 29.8 breaths/min (interquartile range, 23.8-35.7). No event-level average ventilation rate was within guidelines; 30 events (58%) had high ventilation rates. The only significant association between ventilation rate and arterial blood pressure occurred in children 1 year old or older and was present for systolic blood pressure only (-17.8 mm Hg/10 breaths/min; 95% CI, -27.6 to -8.1; p < 0.01). High ventilation rates were associated with a higher odds of survival to discharge (odds ratio, 4.73; p = 0.029). This association was stable after individually controlling for location (adjusted odds ratio, 5.97; p = 0.022), initial rhythm (adjusted odds ratio, 3.87; p = 0.066), and time of day (adjusted odds ratio, 4.12; p = 0.049).

CONCLUSIONS

In this multicenter cohort, ventilation rates exceeding guidelines were common. Among the range of rates delivered, higher rates were associated with improved survival to hospital discharge.

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.

Prevalence and Outcomes of Pediatric In-Hospital Cardiac Arrest Associated With Pulmonary Hypertension

OBJECTIVES

In adult in-hospital cardiac arrest, pulmonary hypertension is associated with worse outcomes, but pulmonary hypertension-associated in-hospital cardiac arrest has not been well studied in children. The objective of this study was to determine the prevalence of pulmonary hypertension among children with in-hospital cardiac arrest and its impact on outcomes.

DESIGN

Retrospective single-center cohort study.

SETTING

PICU of a quaternary care, academic children's hospital.

PATIENTS

Children (<18 yr old) receiving greater than or equal to 1 minute of cardiopulmonary resuscitation (cardiopulmonary resuscitation) for an index in-hospital cardiac arrest with an echocardiogram in the 48 hours preceding in-hospital cardiac arrest, excluding those with cyanotic congenital heart disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 284 in-hospital cardiac arrest subjects, 57 (20%) had evaluable echocardiograms, which were analyzed by a cardiologist blinded to patient characteristics. Pulmonary hypertension was present in 20 of 57 (35%); nine of 20 (45%) had no prior pulmonary hypertension history. Children with pulmonary hypertension had worse right ventricular systolic function, measured by fractional area change (p = 0.005) and right ventricular global longitudinal strain (p = 0.046); more right ventricular dilation (p = 0.010); and better left ventricular systolic function (p = 0.001). Children with pulmonary hypertension were more likely to have abnormal baseline functional status and a history of chronic lung disease or acyanotic congenital heart disease and less likely to have sepsis or acute kidney injury. Children with pulmonary hypertension were more likely to have an initial rhythm of pulseless electrical activity or asystole and were more frequently treated with inhaled nitric oxide (80% vs 32%; p < 0.001) at the time of cardiopulmonary resuscitation. On multivariable analysis, pulmonary hypertension was not associated with event survival (14/20 [70%] vs 24/37 [65%]; adjusted odds ratio, 1.30 [CI95, 0.25-6.69]; p = 0.77) or survival to discharge (8/20 [40%] vs 10/37 [27%]; adjusted odds ratio, 1.17 [CI95, 0.22-6.44]; p = 0.85).

CONCLUSIONS

Pulmonary hypertension physiology preceding pediatric in-hospital cardiac arrest may be more common than previously described. Among this cohort with a high frequency of inhaled nitric oxide treatment during cardiopulmonary resuscitation, pulmonary hypertension was not associated with survival outcomes.

Chest compression rates and pediatric in-hospital cardiac arrest survival outcomes

AIM

The primary aim of this study was to evaluate the association between chest compression rates and 1) arterial blood pressure and 2) survival outcomes during pediatric in-hospital cardiopulmonary resuscitation (CPR).

METHODS

Prospective observational study of children ≥37 weeks gestation and <19 years old who received CPR in an intensive care unit (ICU) as part of the Pediatric Intensive Care Unit Quality of CPR Study (PICqCPR) of the Collaborative Pediatric Critical Care Research Network (CPCCRN). Arterial blood pressure and compression rate were determined from manually extracted arterial line waveform data during the first 10 min of CPR. The primary outcome was survival to hospital discharge. Modified Poisson regression models assessed the association between rate categories (80-<100, 100-120 [Guidelines], >120-140, >140) and outcomes.

RESULTS

Compression rate data were available for 164 patients. More than half (98/164; 60%) were <1 year old. Return of circulation was achieved in 148/164 (90%); survival to hospital discharge in 77/164 (47%). Percentage of events with average rate within Guidelines was 32.9%. Compared to Guidelines, higher rate categories were associated with lower systolic blood pressures (>120-140, p = 0.010; >140, p = 0.077), but not survival. A rate between 80-<100 per minute was associated with a higher rate of survival to hospital discharge (aRR 1.92, CI95 1.13, 3.29, p = 0.017) and survival with favorable neurological outcome (aRR 2.12, CI95 1.09, 4.13, p = 0.027) compared to Guidelines.

CONCLUSION

Non-compliance with compression rate Guidelines was common in this multicenter cohort. Among ICU patients, slightly lower rates were associated with improved outcomes compared to Guidelines.