Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest in Australia: a narrative review

Duration of resuscitation, regain of consciousness and histopathological severity of hypoxic-ischemic encephalopathy after cardiac arrest

Purpose

To study the histopathologically quantified severity of hypoxic-ischemic encephalopathy (HIE) in deceased cardiac arrest unbiased by death causes and correlated with demographic parameters.

Methods

We conducted a retrospective, single-centre study including cardiac arrest patients with postmortem brain autopsies. Using the selective eosinophilic neuronal death (SEND), the histopathological severity of HIE was quantified in the cerebral neocortex, hippocampus, basal ganglia, cerebellum, and brainstem, and correlated with demographic parameters.

Results

We included 319 patients with a median time of return from cardiac arrest to spontaneous circulation (tROSC) of 10 min, of whom 62(19.4%) had a regain of consciousness (RoC) before death. The tROSC was significantly correlated with the SEND in all brain regions (p < 0.05, Spearman's rho = 0.14 to 0.29). The SEND in the neocortex, hippocampus, and basal ganglia was significantly correlated with RoC (p < 0.05, Spearman's rho = -0.25 to -0.11). In 9 patients with tROSCs less than 1 min, all had a brainstem SEND less than 30%, and 8(88.9%) had neocortical SEND less than 30%. Among 69 patients with tROSCs greater than 20 min, 47.8-82.6% showed a SEND less than 30% across brain regions.

Conclusions

We found less SEND and RoC was more likely in patients with shorter tROSCs. A tROSC less than 1 min was mostly associated with SEND less than 30% in all brain regions. Prolonged resuscitations with tROSCs greater than 20 min did not exclude a SEND less than 30% in a relevant proportion of patients. Future histopathological studies are warranted to investigate the impact of modifiable clinical parameters on the severity of HIE.

Pre-hospital ECPR cost analysis and cost effectiveness modelling study

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (ECPR) is increasing. Prehospital ECPR (PH-ECPR) for out-of-hospital cardiac arrest (OHCA) may improve both equity of access and outcomes but its cost effectiveness has yet to be determined.

METHODS

Cost analyses of PH-ECPR was performed utilizing current PH-ECPR trial, NSW Ambulance Cardiac Arrest Registry (CAR), geospatial modelling and in-hospital costings data. Markov modelling was completed to combine the PH-ECPR cost analysis with reported patient outcomes across multiple ECPR strategies. Bridging formulae from ECPR survivor cerebral performance category (CPC) scores were used to estimate cost per quality adjusted life years (QALY) and Incremental Cost Effectiveness Ratios (ICERs). Probabilistic Sensitivity Analysis was completed to assess the probability of cost effectiveness for base case and PH-ECPR strategy variations.

RESULTS

Assuming a base case of 100 patients per year, with a 25% team allocation to ECPR, the average pre-hospital ECPR cost per patient was $12,741 and total of $88,656 AUD equating to approximately $44,000 per QALY. Addition of a conservative 10% kidney organ donation rate reduces the cost per QALY to $22,000. Patient survival rate, the proportion of time the pre-hospital ECPR team are allocated to ECPR and organ donation significantly impact PH-ECPR cost effectiveness.

CONCLUSION

Initial cost analysis and modelling indicate PH-ECPR service strategies are likely to be cost effective and comparable to other medical interventions. Survival rate and service integration into non ECPR clinical tasks are key aspects contributing to cost effectiveness.

Clinician Perspectives of Barriers and Enablers to Quality Cardiogenic Shock Care: A Focus Group Study

BACKGROUND & AIM

Cardiogenic shock is a medical emergency that is associated with high mortality rates. It is a resource-intensive and costly condition that is complicated by comorbidities and clinical deterioration. However, the barriers and enablers to quality cardiogenic shock care are relatively unknown from the perspective of Australian clinicians. This study aimed to i) To explore clinicians' perspectives on the barriers to delivering these best practice care and optimal outcomes for patients with cardiogenic shock; and ii) To understand priorities to overcome these barriers, with the intent of using the findings to inform the development and implementation of a clinical trial for cardiogenic shock management-ESCAPE-CS: Evaluation of a Standardised ClinicAl Pathway to improve Equity and outcomes in Cardiogenic Shock (ESCAPE-CS).

METHOD

A qualitative focus group study was conducted via videoconference with experienced clinicians, and audio-recorded and transcribed verbatim. Data were analysed using thematic analysis in NVivo.

RESULTS

Five focus groups were conducted, including 19 participants (11 male and eight female), comprising seven intensive care unit physicians, seven nurse consultants/educators, three cardiologists, and two emergency department physicians working in metropolitan and rural, regional, or remote health settings. Five themes were identified: CONCLUSIONS: This study provided critical insights into the barriers and possible enablers to delivering best practice care and optimal outcomes for patients with cardiogenic shock. There is scope for an improved model of care in cardiogenic shock management to address inequalities emerging from multifactorial complexities.

Long-term outcomes of patients who received extracorporeal cardiopulmonary resuscitation (ECPR) following in-hospital cardiac arrest: Analysis of EXCEL registry data

Objective

To describe the six-month functional outcomes of patients who received extracorporeal cardiopulmonary resuscitation (ECPR) following in-hospital cardiac arrest (IHCA) in Australia.

Design

Secondary analysis of EXCEL registry data.

Setting

EXCEL is a high-quality, prospective, binational registry including adult patients who receive extracorporeal membrane oxygenation (ECMO) in Australia and New Zealand.

Participants

Patients reported to the EXCEL registry who received ECPR following IHCA and had the six-month outcome data available were included.

Main outcome measures

The primary outcome was functional outcome at six months measured using the modified Rankin scale (mRS). The secondary outcomes included mortality, disability, health status, and complications.

Results

Between 15th February 2019 and 31st August 2022, 113/1251 (9.0%) patients in the registry received ECPR following IHCA (mean age 50.7 ± 13.7 years; 79/113 (69.9%) male; 74/113 (65.5%) non-shockable rhythm). At 6 months, 37/113 (32.7%) patients were alive, most (27/34 [79.4%]) with a good functional outcome (mRS 0-3). Patients had increased disability [WHODAS % Score 25.58 ± 23.39% vs 6.45 ± 12.32%; mean difference (MD) [95% (confidence interval) CI] -19.13 (-28.49 to -9.77); p < 0.001] and worse health status [EuroQol five-dimension, five-level (EQ-5D-5L) index value 0.73 ± 0.23 vs. 0.89 ± 0.14; MD (95% CI) 0.17 (0.07 to 0.26); p = 0.003] at six months compared with the baseline. The patients reported a median of 4.5 (2-6) complications at six-month follow-up.

Conclusion

One in three patients who received ECPR following IHCA were alive at six months and most had a good functional outcome. However, survivors reported higher levels of disability and a worse health status at six months compared with the baseline and ongoing complications were common.