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BACKGROUND: Biosensor technologies have been proposed as a solution to provide recognition and facilitate earlier responses to unwitnessed out-of-hospital cardiac arrest (OHCA) cases. We sought to estimate the effect of recognition on survival and modelled the potential incremental impact of increased recognition of unwitnessed cases on survival to hospital discharge, to demonstrate the potential benefit of biosensor technologies. METHODS: We included cases from the British Columbia Cardiac Arrest Registry (2019-2020), which includes Emergency Medical Services (EMS)-assessed OHCAs. We excluded cases that would not have benefitted from early recognition (EMS-witnessed, terminal illness, or do-not-resuscitate). Using a mediation analysis, we estimated the relative benefits on survival of a witness recognizing vs. intervening in an OHCA; and estimated the expected additional number of survivors resulting from increasing recognition alone using a bootstrap logistic regression framework. RESULTS: Of 13,655 EMS-assessed cases, 11,412 were included (6314 EMS-treated, 5098 EMS-untreated). Survival to hospital discharge was 191/8879 (2.2%) in unwitnessed cases and 429/2533 (17%) in bystander-witnessed cases. Of the total effect attributable to a bystander witness, recognition accounted for 84% (95% CI: 72, 86) of the benefit. If all previously unwitnessed cases had been bystander witnessed, we would expect 1198 additional survivors. If these cases had been recognized, but no interventions performed, we would expect 912 additional survivors. CONCLUSION: Unwitnessed OHCA account for the majority of OHCAs, yet survival is dismal. Methods to improve recognition, such as with biosensor technologies, may lead to substantial improvements in overall survival.

Assuntos

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BACKGROUND: After resuscitation from out-of-hospital cardiac arrest (OHCA) by Emergency Medical Services (EMS), the amount of time that should be dedicated to pre-transport stabilization is unclear. We examined whether the time spent on-scene after return of spontaneous circulation (ROSC) was associated with patient outcomes. METHODS: We examined consecutive adult EMS-treated OHCAs from the British Columbia Cardiac Arrest registry (January 1/2019-June 1/2021) that had on-scene ROSC (sustained to scene departure). The primary outcome was favourable neurological outcome (Cerebral Performance Category ≤ 2) at hospital discharge; secondary outcomes were re-arrest during transport and hospital-discharge survival. Using adjusted logistic regression models, we estimated the association between the post-resuscitation on-scene interval (divided into quartiles) and outcomes. RESULTS: Of 1653 cases, 611 (37%) survived to hospital discharge, and 523 (32%) had favourable neurological outcomes. The median post-resuscitation on-scene interval was 18.8 minutes (IQR:13.0-25.5). Compared to the first post-resuscitation on-scene interval quartile, neither the second (adjusted odds ratio [AOR] 1.19; 95% CI 0.72-1.98), third (AOR 1.10; 95% CI 0.67-1.81), nor fourth (AOR 1.54; 95% CI 0.93-2.56) quartiles were associated with favourable neurological outcomes; however, the fourth quartile was associated with a greater odds of hospital-discharge survival (AOR 1.73; 95% CI 1.05-2.85), and both the third (AOR 0.40; 95% CI 0.22-0.72) and fourth (AOR 0.44;95% CI 0.24-0.81) quartiles were associated with a lower odds of intra-transport re-arrest. CONCLUSION: Among resuscitated OHCAs, increased post-resuscitation on-scene time was not associated with improved neurological outcomes, but was associated with improved survival to hospital discharge and decreased intra-transport re-arrest.

Assuntos

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AIM: Longer emergency medical system cardiopulmonary-resuscitation-to-return of-spontaneous-circulation (EMS CPR-to-ROSC) interval has been associated with worse hospital discharge outcomes after out-of-hospital cardiac arrest (OHCA). We hypothesized that this association extends post-discharge in hospital survivors. We investigated whether pre-arrest co-morbidities influence the duration of resuscitation. METHODS: We included EMS-treated adult OHCA (January 2009 - December 2016) from British Columbia Cardiac Arrest Registry linked to provincial databases. Pre-OHCA characteristics were compared by ≤10, 10-20, and >20 min interval categories. Outcomes included survival and functional outcomes at hospital discharge and 1- and 3-year survival. We examined the relationship between CPR-to-ROSC intervals and survival using Kaplan-Meier. We examined the relationship between the CPR-to-ROSC interval (continuous variable) with all outcomes using regression models. RESULTS: Among 10,241 OHCA, 4604 (45%) achieved ROSC, with a median CPR-to-ROSC interval of 15.5 (IQR 9.0-22.9) minutes. Diabetes, chronic kidney disease, and prior myocardial infarction were associated with longer CPR-to-ROSC intervals. 1245 (12.2%) survived to hospital discharge. Among hospital survivors, Kaplan-Meier survival at 1- and 3-years were 92% [95% CI 90-93%] and 84% [95% CI 82-86%] respectively; survival curves stratified by CPR-to-ROSC intervals were not statistically different. Longer CPR-to-ROSC interval was non-linearly associated with lower survival and functional outcomes at hospital discharge but not with post-discharge outcomes. CONCLUSION: Longer CPR-to-ROSC interval was associated with lower survival at hospital discharge and was influenced by pre-arrest co-morbidities. However, these intervals were not associated with long-term survival or functional outcome among hospital survivors, suggesting early risk of longer CPR-to-ROSC intervals does not persist.

Assuntos

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BACKGROUND: Emergency dispatch centres receive emergency calls and assign resources. Out-of-hospital cardiac arrests (OHCA) can be classified as appropriate (requiring emergent response) or inappropriate (requiring non-emergent response) for resuscitation. We sought to determine system accuracy in emergency medical services (EMS) OHCA response allocation. METHODS: We analyzed EMS-assessed non-traumatic OHCA records from the British Columbia (BC) Cardiac Arrest registry (January 1, 2019-June 1, 2021), excluding EMS-witnessed cases. In BC the "Medical Priority Dispatch System" is used. We classified EMS dispatch as "emergent" or "non-emergent" and compared to the gold standard of whether EMS personnel decided treatment was appropriate upon scene arrival. We calculated sensitivity, specificity, and positive and negative predictive values (PPV, NPV), with 95% CI's. RESULTS: Of 15,371 non-traumatic OHCAs, the median age was 65 (inter quartile range 51-78), and 4834 (31%) were women; 7152 (47%) were EMS-treated, of whom 651 (9.1%) survived). Among EMS-treated cases 6923/7152 had an emergent response (sensitivity = 97%, 95% CI 96-97) and among EMS-untreated cases 3951/8219 had a non-emergent response (specificity = 48%, 95% CI, 47 to 49). Among cases with emergent dispatch, 6923/11191 were EMS-treated (PPV = 62%, 95% CI 61-62), and among those with non-emergent dispatch, 3951/4180 were EMS-untreated (NPV = 95%, 95% CI 94-95); 229/4180 (5.5%) with a non-emergent dispatch were treated by EMS. CONCLUSION: The dispatch system in BC has a high sensitivity and moderate specificity in sending the appropriate responses for OHCAs deemed appropriate for treatment by paramedics. Future research may address strategies to increase system specificity, and decrease the incidence of non-emergent dispatch to EMS-treated cases.

Assuntos

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Aim: Cardiac arrest (CA) is the cessation of circulation to vital organs that can only be reversed with rapid and appropriate interventions. Sensor technologies for early detection and activation of the emergency medical system could enable rapid response to CA and increase the probability of survival. We conducted a systematic review to summarize the literature surrounding the performance of sensor technologies in detecting OHCA. Methods: We searched the academic and grey literature using keywords related to cardiac arrest, sensor technologies, and recognition/detection. We included English articles published up until June 6, 2022, including investigations and patent filings that reported the sensitivity and specificity of sensor technologies to detect cardiac arrest on human or animal subjects. (Prospero# CRD42021267797). Results: We screened 1666 articles and included four publications examining sensor technologies. One tested the performance of a physical sensor on human participants in simulated CA, one tested performance on audio recordings of patients in cardiac arrest, and two utilized a hybrid design for testing including human participants and ECG databases. Three of the devices were wearable and one was an audio detection algorithm utilizing household smart technologies. Real-world testing was limited in all studies. Sensitivity and specificity for the sensors ranged from 97.2 to 100% and 90.3 to 99.9%, respectively. All included studies had a medium/high risk of bias, with 2/4 having a high risk of bias. Conclusions: Sensor technologies show promise for cardiac arrest detection. However, current evidence is sparse and of high risk of bias. Small sample sizes and databases with low external validity limit the generalizability of findings.

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BACKGROUND: Half of out-of-hospital cardiac arrests (OHCA) are deemed inappropriate for resuscitation by emergency medical services (EMS). We investigated patient characteristics and reasons for non-treatment of OHCAs, and determined the proportion involving illicit drug use. METHODS: We reviewed consecutive EMS-untreated OHCA from the British Columbia Cardiac Arrest Registry (2019-2020). We abstracted patient characteristics and categorized reasons for EMS non-treatment: (1) prolonged interval from the OHCA to EMS arrival ("non-recent OHCA") with or without signs of "obvious death"; (2) do-not-resuscitate (DNR) order; (3) terminal disease; (4) verbal directive; and (5) unspecified. We abstracted clinical details regarding a history of, or evidence at the scene of, illicit drug use. RESULTS: Of 13 331 cases, 5959 (45%) were not treated by EMS. The median age was 67 (IQR 54-81) and 1903 (32%) were female. EMS withheld resuscitation due to: non-recent OHCA, with and without signs of "obvious death" in 4749 (80%) and 108 (1.8%), respectively; DNR order in 952 (16%); terminal disease in 77 (1.3%); family directive in 41 (0.69%); and unspecified in 32 (0.54%). Overall and among those with non-recent OHCA, 695/5959 (12%) and 691/4857 (14%) had either a history of or evidence of recent illicit drug use, respectively. CONCLUSION: A prolonged interval from the OHCA until EMS assessment was the predominant reason for withholding treatment. Innovative solutions to decrease this interval may increase the proportion of OHCA that are treated by EMS and overall outcomes. Targeted interventions for illicit-drug use-related OHCAs may add additional benefit.

Assuntos