Association between direct transport to a cardiac arrest centre and survival following out-of-hospital cardiac arrest: A propensity-matched Aotearoa New Zealand study.

Background and Objectives: Direct transport to a cardiac arrest centre following out-of-hospital cardiac arrest may be associated with higher survival. However, there is limited evidence available to support this within the New Zealand context. This study used a propensity score-matched cohort to investigate whether direct transport to a cardiac arrest centre improved survival in New Zealand. Methods: A retrospective cohort study was conducted using the Aotearoa New Zealand Paramedic Care Collection (ANZPaCC) database for adults treated for out-of-hospital cardiac arrest of presumed cardiac aetiology between 1 July 2018 to 30 June 2023. Propensity score-matched analysis was used to investigate survival at 30-days post-event according to the receiving hospital being a cardiac arrest centre versus a non-cardiac arrest centre. Results: There were 2,297 OHCA patients included. Propensity matching resulted in 554 matched pairs (n = 1108). Thirty-day survival in propensity score-matched patients transported directly to a cardiac arrest centre (56%) versus a non-cardiac arrest centre (45%) was not significantly different (adjusted Odds Ratio 0.78 95%CI 0.54, 1.13, p = 0.19). Shockable presenting rhythm, bystander CPR, and presence of STEMI were associated with a higher odds of 30 day survival (p < 0.05). Maori or Pacific Peoples ethnicity and older age were associated with lower survival (p < 0.05). Conclusions: This study found no statistically significant difference in outcomes for OHCA patients transferred to a cardiac arrest compared to a non-cardiac arrest centre. However, the odds ratio of 0.78, equivalent to a 22% decrease in 30-day mortality, is consistent with benefit associated with management by a cardiac arrest centre. Further research in larger cohorts with detailed information on known outcome predictors, or large randomised clinical trials are needed.

Enhancing Aotearoa, New Zealand's Free Healthline Service through Image Upload Technology.

Background: Healthline is one of the 39 free telehealth services that Whakarongorau Aotearoa/New Zealand Telehealth Services provides to New Zealanders. In early 2021, an image upload system for viewing service user-uploaded images was implemented into the Healthline service. Aims: The aim of this research was to understand the utilisation of Healthline's image upload system by clinicians and service users in New Zealand. Methods: This is a retrospective observational study analysing Healthline image upload data over a two-year period: March 2021 through to December 2022. A total of 40,045 images were analysed, including demographics of the service users who uploaded an image: ethnicity, age group, and area of residence. The outcome or recommendation of the Healthline call was also assessed based on whether an image was included. Results: Images uploaded accounted for 6.0% of total Healthline calls (n = 671,564). This research found that more service users were advised to go to an Emergency Department if they did not upload an image compared to service users who used the tool (13.5% vs. 7.7%), whereas a higher proportion of service users were given a lower acuity outcome if they included an image, including visiting an Urgent Care (24.0% vs. 16.9%) and GP (36.7% vs. 24.3%). Conclusion: Service users who did not upload an image had a higher proportion of Emergency Department outcomes than service users who did use the tool. This image upload tool has shown the potential to decrease stress on Emergency Departments around Aotearoa, New Zealand, through increased lower acuity outcomes.

Naloxone use by Aotearoa New Zealand emergency medical services, 2017-2021.

OBJECTIVE: Emergency medical services (EMS) use of naloxone in the prehospital setting is indicated in patients who have significantly impaired breathing or level of consciousness when opioid intoxication is suspected. The present study characterised naloxone use in a nationwide sample of Aotearoa New Zealand road EMS patients to establish a baseline for surveillance of any changes in the future. METHODS: A retrospective analysis of rates of patients with naloxone administrations was conducted using Hato Hone St John (2017-2021) and Wellington Free Ambulance (2018-2021) electronic patient report form datasets. Patient demographics, presenting complaints, naloxone dosing, and initial and last vital sign clinical observations were described. RESULTS: There were 2018 patients with an equal proportion of males and females, and patient median age was 47 years. There were between 8.0 (in 2018) and 9.0 (in 2020) naloxone administrations per 100 000 population-years, or approximately one administration per day for the whole country of 5 million people. Poisoning by unknown agent(s) was the most common presenting complaint (61%). The median dose of naloxone per patient was 0.4 mg; 85% was administered intravenously. The median observed change in Glasgow Coma Scale score was +1, and respiratory rate increased by +2 breaths/min. CONCLUSIONS: A national rate of EMS naloxone patients was established; measured clinical effects of naloxone were modest, suggesting many patients had reasons other than opioid toxicity contributing to their symptoms. Naloxone administration rates provide indirect surveillance information about suspected harmful opioid exposures but need to be interpreted with care.

Out-of-Hospital emergency airway management practices: A nationwide observational study from Aotearoa New Zealand.

Background and Objectives: Airway management is crucial for emergency care in critically ill patients outside the hospital setting. An Airway Registry is useful in providing essential information for quality improvement purposes. Therefore, this study aimed to develop an out-of-hospital airway registry and describe airway management practices in Aotearoa New Zealand (AoNZ). Methods: Data from the Aotearoa New Zealand Paramedic Care Collection (ANZPaCC) database were used in a retrospective cohort study covering July 2020 to June 2021. All patients receiving airway interventions were included. An airway intervention was defined as one or more of the following: non-drug assisted endotracheal intubation (NDA-ETI), drug-assisted endotracheal intubation (DA-ETI; where a combination of paralytic agent and sedative were used to aid in intubation), laryngeal mask airway (LMA), oropharyngeal airway (OPA), nasopharyngeal airway (NPA), surgical airway (cricothyroidotomy), suction, jaw thrust. Descriptive statistics were analysed using Chi-Square and logistic regression modelling investigated the relationship between advanced airway success and patient characteristics. Results: The study included 4,529 patients who underwent 7,779 airway interventions. Basic airway interventions were used most frequently: OPA (45.1%), NPA (29.3%), LMA (28.9%), suction (19.9%) and jaw thrust (17.6%). Advanced airway interventions were used less frequently: NDA-ETI (19.8%), DA-ETI (8.7%), and surgical airways (0.2%). The success rate for ETI (including both NDA-ETI and DA-ETI) was 89.4%, with NDA-ETI success at 85.8% and DA-ETI success at 97.7%. ETI first-pass success rates were significantly lower for males (aOR 0.65, 95%CI 0.48-0.87, p < 0.001) and higher for non-cardiac arrest injury patients (aOR 2.94, 95%CI 1.43-6.00, p < 0.001). In this cohort receiving airway interventions the 1-day mortality rate was 41.1%, demonstrating that a high proportion of these patients were severely clinically compromised. Conclusions: Out-of-hospital airway management practices and success rates in AoNZ are comparable to those elsewhere. This research has determined the variables to be used as the AoNZ Paramedic Airway Registry ongoing and has demonstrated baseline outcomes in airway management for ongoing quality improvement using this registry.

Prehospital identification of ST-segment elevation myocardial infarction and mortality (ANZACS-QI 61).

BACKGROUND: Early recognition of ST-segment elevation myocardial infarction (STEMI) is needed for timely cardiac monitoring and reperfusion therapy. METHODS: Three anonymously linked New Zealand national datasets (July 2016-November 2018) were used to assess the utilisation of ambulance transport in STEMI cases, the concordance between ambulance initial clinical impressions and hospital STEMI diagnoses, and the association between initial paramedic clinical impressions and 30-day mortality. The St John Ambulance electronic record captures community call-outs and paramedic initial clinical impressions. The national cardiac (ANZACS-QI) registry and national administrative datasets capture all New Zealand public hospital admission diagnoses and mortality data. RESULTS: Of 5465 patients with STEMI, 73% were transported to hospital by ambulance. For these patients, the initial paramedic impression was STEMI in 50.7%, another acute coronary syndrome (ACS) diagnosis in 19.9% and non-ACS diagnosis in 29.7%. Only 37% of the 5465 patients with STEMI were both transported by ambulance and clinically suspected of STEMI by paramedics. Compared with patients with paramedic-'suspected STEMI', 30-day mortality was over threefold higher for patients thought to have a non-ACS condition (10.9% and 34.9%, respectively), but after adjustment for available covariates, this was substantially ameliorated (HR 1.48, 95% CI 1.22 to 1.80). CONCLUSIONS: In this national data linkage study, only 4 out of every 10 patients with STEMI were both transported by ambulance and had STEMI suspected by paramedics. Although patients with STEMI not suspected of an ACS diagnosis by paramedics had the highest mortality rate, this is largely explained by the different risk profile of these patients.

Positive association between ambulance double-crewing and OHCA outcomes: A New Zealand observational study.

BACKGROUND AND OBJECTIVES: New Zealand emergency medical service (EMS) crewing configurations generally place one (single) or two (double) crew on each responding ambulance unit. Recent studies demonstrated that double-crewing was associated with improved survival from out-of-hospital cardiac arrest (OHCA), therefore single-crewed ambulances have been phased out. We aimed to determine the association between this crewing policy change and OHCA outcomes in New Zealand. METHODS: This is a retrospective observational study using data from the St John OHCA Registry on patients treated during two different time periods: the Pre-Period (1 October 2013-30 June 2015), when single-crewed ambulances were in use by EMS, and the Post-Period (1 July 2016-30 June 2018) when single-crewed ambulances were being phased out. Geographic areas identified as having low levels of double crewing during the Pre-Period were selected for investigation. The outcome of survival to thirty-days post-OHCA was investigated using logistic regression analysis. RESULTS: The proportion of double-crewed ambulances arriving at OHCA events increased in the Post-Period (81.8%) compared to the Pre-Period (67.5%) (p ≤ 0.001). Response times decreased by two minutes (Pre-Period: median 8 min, IQR [6-11], Post-Period: median 6 min, IQR [4-9]; p ≤ 0.001). Thirty-day survival was significantly improved in the Post-Period (OR 1.63, 95%CI (1.04-2.55), p = 0.03). CONCLUSIONS: An association between improved OHCA survival following increased responses by double-crewed ambulances was demonstrated. This study suggests that improvements in resourcing are associated with improved OHCA outcomes.

Factors Associated with Emergency Medical Service Reattendance in Low Acuity Patients Not Transported by Ambulance.

Background: The decision for emergency medical services (EMS) personnel not to transport a patient is challenging: there is a risk of subsequent deterioration but transportation of all patients to hospital would overburden emergency departments. The aim of this large-scale EMS study was to identify factors associated with an increased likelihood of ambulance reattendance within 48 hours in low acuity patients who were not transported by ambulance.Methods: We conducted a 2-year retrospective cohort study using data from the St John New Zealand EMS between 1 July 2016 and 30 June 2018 to investigate demographic and clinical associations with ambulance reattendance.Results: In total, 83,171 low acuity patients not transported by ambulance were included, of whom 4,512 (5.4%) had an EMS ambulance reattend within 48 hours. There were significant associations between EMS reattendance and patient age, sex, ethnicity, deprivation, and event location. Patients aged 60-74 years old had the highest likelihood of ambulance recall (OR 2.87, 95% CI: 2.51-3.28). Males were more likely to have an EMS ambulance reattend within 48 hours (OR 1.17, 95% CI: 1.09-1.25). Maori and Pacific Peoples had a similar likelihood of EMS recall to European/Others; however, the Asian cohort showed a reduced likelihood of reattendance (OR 0.76, 95% CI: 0.62-0.93).There were significant associations between EMS reattendance and non-transport reason, time spent on scene, event type, clinical acuity level (status), and pain score. Shorter (<30 minutes) on scene times were associated with a decreased likelihood of ambulance reattendance, whereas longer scene times (>45 minutes) were associated with an increased likelihood. Medical events were more likely to require reattendance than accident-related events (OR 1.22, 95% CI: 1.13-1.32). Non-transported patients with a severe pain score (7-10/10) were at increased likelihood of requiring reattendance (OR 1.60, 95% CI: 1.33-1.92).Discussion: The overall low rate of EMS reattendance is encouraging. Further research is needed into the clinical presentation of patients requiring ambulance reattendance within 48 hours to determine if there are early warning signs indicative of subsequent deterioration.

The impact of a national COVID-19 lockdown on acute coronary syndrome hospitalisations in New Zealand (ANZACS-QI 55).

BACKGROUND: Countries with a high incidence of coronavirus 2019 (COVID-19) reported reduced hospitalisations for acute coronary syndromes (ACS) during the pandemic. This study describes the impact of a nationwide lockdown on ACS hospitalisations in New Zealand (NZ), a country with a low incidence of COVID-19. METHODS: All patients admitted to a NZ Hospital with ACS who underwent coronary angiography in the All NZ ACS Quality Improvement registry during the lockdown (23 March - 26 April 2020) were compared with equivalent weeks in 2015-2019. Ambulance attendances and regional community troponin-I testing were compared for lockdown and non-lockdown (1 July 2019 to 16 February 2020) periods. FINDINGS: Hospitalisation for ACS was lower during the 5-week lockdown (105 vs. 146 per-week, rate ratio 0•72 [95% CI 0•61-0•83], p = 0.003). This was explained by fewer admissions for non-ST-segment elevation ACS (NSTE-ACS; p = 0•002) but not ST-segment elevation myocardial infarction (STEMI; p = 0•31). Patient characteristics and in-hospital mortality were similar. For STEMI, door-to-balloon times were similar (70 vs. 72 min, p = 0•52). For NSTE-ACS, there was an increase in percutaneous revascularisation (59% vs. 49%, p<0•001) and reduction in surgical revascularisation (9% vs. 15%, p = 0•005). There were fewer ambulance attendances for cardiac arrests (98 vs. 110 per-week, p = 0•04) but no difference for suspected ACS (408 vs. 420 per-week, p = 0•44). Community troponin testing was lower throughout the lockdown (182 vs. 394 per-week, p<0•001). INTERPRETATION: Despite the low incidence of COVID-19, there was a nationwide decrease in ACS hospitalisations during the lockdown. These findings have important implications for future pandemic planning. FUNDING: The ANZACS-QI registry receives funding from the New Zealand Ministry of Health.

Ethnic disparities in the incidence and outcome from out-of-hospital cardiac arrest: A New Zealand observational study.

BACKGROUND: New Zealand (NZ) has an ethnically diverse population. International studies have demonstrated significant differences in health equity by ethnicity; however, there is limited evidence in the context of out-of-hospital cardiac arrest in NZ. We investigated whether heath disparities in incidence and outcome of out-of-hospital cardiac arrest exist between NZ ethnic groups. METHOD: A retrospective observational study was conducted using NZ cardiac arrest registry data for a 2-year period. Ethnic cohorts investigated were the indigenous Maori population, Pacific Peoples and European/Others. Incidence rates, population characteristics and outcomes (Return of Spontaneous Circulation sustained to hospital handover and thirty-day survival) were compared. RESULTS: Age-adjusted incidence rates per 100,000 person-years were higher in Maori (144.4) and Pacific Peoples (113.5) compared to European/Others (93.8). Return of spontaneous circulation sustained to hospital handover was significantly lower in Maori (adjusted OR 0.74, 95% CI 0.64-0.87, p < 0.001). Survival to thirty-days was lower for both Maori (adjusted OR 0.61, 95% CI 0.48-0.78, p < 0.001) and Pacific Peoples (adjusted OR 0.52, 95% CI 0.37-0.72, p < 0.001). A higher proportion of events occurred in all age groups below 65 years old in Maori and Pacific Peoples (p < 0.001), and a higher proportion of events occurred among women in Maori and Pacific Peoples (p < 0.001). CONCLUSIONS: There are significant differences in health equity by ethnicity. Both Maori and Pacific Peoples have higher incidence of out-of-hospital cardiac arrest and at a younger age. Maori and Pacific Peoples have lower rates of survival to thirty-days. Our results provide impetus for targeted health strategies for at-risk ethnic populations.

Direct transport to PCI-capable hospitals after out-of-hospital cardiac arrest in New Zealand: Inequities and outcomes.

BACKGROUND: It is widely accepted that survival from OHCA may be improved through direct transfer of patients to hospitals with percutaneous coronary intervention (PCI) capability. However, within the New Zealand healthcare system there is limited evidence available to support this. We aimed to compare patient characteristics and outcomes following an out-of-hospital cardiac arrest between those patients transported to hospitals with or without PCI-capability within New Zealand. METHOD: A retrospective cohort study was conducted using data from the St John New Zealand OHCA registry for adults treated for an out-of-hospital cardiac arrest of presumed cardiac aetiology between 1 October 2013 and 31 October 2018. Population characteristics were investigated using a Chi-Square analysis. Binary logistic regression modelling was used to investigate outcome differences in survival at 30 days post-event according to receiving hospital PCI-capability. RESULTS: The study included 1750 patients who were transported to hospital following an OHCA. A significantly lower proportion of patients over 65 years (49.9%) were conveyed to hospitals with PCI-capability compared to younger aged patients (15-44 years (52.1%) and 45-64 years (59.7%) (p < 0.001). When ethnic groups were compared, Maori (32.9%) had the lowest proportion transported to PCI-capable hospitals, followed by European (55.6%) then Pacific Peoples (86.2%) (p < 0.001). A lower proportion of patients located rurally (34.7%) were transported to hospitals with PCI-capability compared to patients in an urban location (59.1%) (p < 0.001). Thirty-day survival was higher in patients transported to hospitals with PCI-capability (adjusted OR 1.285, 95%CI (1.01-1.63), p = 0.04). CONCLUSIONS: Patient characteristic differences indicate that inequities in healthcare may exist in New Zealand related to age, ethnic group, and rurality. Thirty-day survival was significantly increased in patients conveyed directly to a hospital with PCI-capability.