Efficacy of endotracheal intubation in helicopter cabin vs. ground: a systematic review and meta-analysis.

BACKGROUND: Pre-hospital endotracheal intubation (ETI) is a sophisticated procedure with a comparatively high failure rate. Especially, ETI in confined spaces may result in higher difficulty, longer times, and a higher failure rate. This study analyses if Helicopter Emergency Medical Services (HEMS) intubation (time-to) success are influenced by noise, light, and restricted space in comparison to ground intubation. Available literature reporting these parameters was very limited, thus the reported differences between ETI in helicopter vs. ground by confronting parameters such as time to secure airway, first pass success rate and Cormack-Lehane Score were analysed. METHODS: A systematic review and meta-analysis were conducted using PUBMED, EMBASE, Cochrane Library, and Ovid on October 15th, 2022. The database search provided 2322 studies and 6 studies met inclusion and quality criteria. The research was registered with the International Prospective Register of Systematic Reviews (CRD42022361793). RESULTS: A total of six studies were selected and analysed as part of the systematic review and meta-analysis. The first pass success rate of ETI was more likely to fail in the helicopter setting as compared to the ground (82,4% vs. 87,3%), but the final success rate was similar between the two settings (96,8% vs. 97,8%). The success rate of intubation in literature was reported higher in physician-staffed HEMS than in paramedic-staffed HEMS. The impact of aircraft type and location inside the vehicle on intubation success rates was inconclusive across studies. The meta-analysis revealed inconsistent results for the mean duration of intubation, with one study reporting shorter intubation times in helicopters (13,0s vs.15,5s), another reporting no significant differences (16,5s vs. 16,8s), and a third reporting longer intubation times in helicopters (16,1s vs. 15,0s). CONCLUSION: Further research is needed to assess the impact of environmental factors on the quality of ETI on HEMS. While the success rate of endotracheal intubation in helicopters vs. on the ground is not significantly different, the duration and time to secure the airway, and Cormack-Lehane Score may be influenced by environmental factors. However, the limited number of studies reporting on these factors highlights the need for further research in this area.

Effectiveness and safety of prehospital analgesia with nalbuphine and paracetamol versus morphine by paramedics - an observational study.

BACKGROUND: Despite the development of various analgesic concepts, prehospital oligoanalgesia remains very common. The present work examines prehospital analgesia by paramedics using morphine vs. nalbuphine + paracetamol. METHODS: Patients with out-of-hospital-analgesia performed by paramedics from the emergency medical services of the districts of Fulda (morphine) and Gütersloh (nalbuphine + paracetamol) were evaluated with regards to pain intensity at the beginning and the end of prehospital treatment using the Numeric-Rating-Scale for pain (NRS), sex, age, and complications. The primary endpoint was achievement of adequate analgesia, defined as NRS < 4 at hospital handover, depending on the analgesics administered (nalbuphine + paracetamol vs. morphine). Pain intensity before and after receiving analgesia using the NRS, sex, age and complications were also monitored. RESULTS: A total of 1,808 patients who received out-of-hospital-analgesia were evaluated (nalbuphine + paracetamol: 1,635 (90.4%), NRS-initial: 8.0 ± 1.4, NRS-at-handover: 3.7 ± 2.0; morphine: 173(9.6%), NRS-initial: 8.5 ± 1.1, NRS-at-handover: 5.1 ± 2.0). Factors influencing the difference in NRS were: initial pain intensity on the NRS (regression coefficient (RK): 0.7276, 95%CI: 0.6602-0.7950, p < 0.001), therapy with morphine vs. nalbuphine + paracetamol (RK: -1.2594, 95%CI: -1.5770 - -0.9418, p < 0.001) and traumatic vs. non-traumatic causes of pain (RK: -0.2952, 95%CI: -0.4879 - -0.1024, p = 0.002). Therapy with morphine (n = 34 (19.6%)) compared to nalbuphine + paracetamol (n = 796 (48.7%)) (odds ratio (OR): 0.274, 95%CI: 0.185-0.405, p < 0.001) and the initial NRS score (OR:0.827, 95%CI: 0.771-0.887, p < 0.001) reduced the odds of having an NRS < 4 at hospital handover. Complications occurred with morphine in n = 10 (5.8%) and with nalbuphine + paracetamol in n = 35 (2.1%) cases. Risk factors for complications were analgesia with morphine (OR: 2.690, 95%CI: 1.287-5.621, p = 0.008), female sex (OR: 2.024, 95%CI: 1.040-3.937, p = 0.0379), as well as age (OR: 1.018, 95%CI: 1.003-1.034, p = 0.02). CONCLUSIONS: Compared to morphine, prehospital analgesia with nalbuphine + paracetamol yields favourable effects in terms of analgesic effectiveness and a lower rate of complications and should therefore be considered in future recommendations for prehospital analgesia.

Prehospital anesthesia in postcardiac arrest patients: a multicenter retrospective cohort study.

BACKGROUND: Currently, the data regarding the impact of prehospital postcardiac arrest anesthesia on target hemodynamic and ventilatory parameters of early postresuscitation care and recommendations on its implementation are rare. The present study examines the incidence and impact of prehospital postcardiac arrest anesthesia on hemodynamic and ventilatory target parameters of postresuscitation care. METHODS: In this multicentre observational study between 2019 and 2021 unconscious adult patients after out-of-hospital-cardiac arrest with the presence of a return-of-spontaneous circulation until hospital admission were included. Primary endpoint was the application of postarrest anesthesia. Secondary endpoints included the medication group used, predisposing factors to its implementation, and its influence on achieving target parameters of postresuscitation care (systolic blood pressure: ≥ 100 mmHg, etCO2:35-45 mmHg, SpO2: 94-98%) at hospital handover. RESULTS: During the study period 2,335 out-of-hospital resuscitations out of 391,305 prehospital emergency operations (incidence: 0.58%; 95% CI 0.54-0.63) were observed with a return of spontaneous circulation to hospital admission in 706 patients (30.7%; 95% CI 28.8-32.6; female: 34.3%; age:68.3 ± 14.2 years). Postcardiac arrest anesthesia was performed in 482 patients (68.3%; 95% CI 64.7-71.7) with application of hypnotics in 93.4% (n = 451), analgesics in 53.7% (n = 259) and relaxants in 45.6% (n = 220). Factors influencing postcardiac arrest sedation were emergency care by an anesthetist (odds ratio: 2.10; 95% CI 1.34-3.30; P < 0.001) and treatment-free interval ≤ 5 min (odds ratio: 1.59; 95% CI 1.01-2.49; P = 0.04). Although there was no evidence of the impact of performing postcardiac arrest anesthesia on achieving a systolic blood pressure ≥ 100 mmHg at the end of operation (odds ratio: 1.14; 95% CI 0.78-1.68; P = 0.48), patients with postcardiac arrest anesthesia were significantly more likely to achieve the recommended ventilation (odds ratio: 1.59; 95% CI 1.06-2.40; P = 0.02) and oxygenation (odds ratio:1.56; 95% CI 1.04-2.35; P = 0.03) targets. Comparing the substance groups, the use of hypnotics significantly more often enabled the target values for etCO2 to be reached alone (odds ratio:2.79; 95% CI 1.04-7.50; P = 0.04) as well as in combination with a systolic blood pressure ≥ 100 mmHg (odds ratio:4.42; 95% CI 1.03-19.01; P = 0.04). CONCLUSIONS: Postcardiac arrest anesthesia in out-of-hospital cardiac arrest is associated with early achievement of respiratory target parameters in prehospital postresuscitation care without evidence of more frequent hemodynamic complications.

[Phone triage in primary care practices]. / Triage téléphonique en cabinet de médecine de famille.

In primary care medicine for adult or pediatric populations, phone calls from patients or parents are common. The variety of questions is broad, going from simple administrative requests to life-threatening emergencies. The safety of the patient is the main priority when answering these calls. In opposition to emergency departments in hospitals where numerous well-defined triage systems (for example, Swiss Emergency Triage Scale), including clinical exam with vital signs, have been used, it is difficult to find practical guidelines for a safe and efficient phone triage in medical practices. Swiss pediatricians already use a triage book to help them assess the need for emergency care for their young patients. A similar type of resource would be helpful for a safe management of calls in adult medicine.

En cabinet de médecine de famille, adulte ou pédiatrique, les appels téléphoniques de patients ou de leurs proches sont nombreux. Leurs questions sont variées, allant de la simple requête administrative à l'urgence vitale. La sécurité du patient reste la priorité principale dans les réponses apportées lors de ces appels. Contrairement aux systèmes d'urgences hospitalières utilisant de multiples échelles de tri comprenant un examen clinique de base avec signes vitaux (par exemple, Échelle suisse de tri), il existe peu de stratégies pour un triage efficace et sûr en médecine de cabinet. Les pédiatres suisses utilisent actuellement un guide au triage téléphonique visant à cibler correctement les besoins urgents de soins pour leurs jeunes patients. Un équivalent pour la médecine adulte serait une aide supplémentaire pour une prise en charge en toute sécurité.

A retrospective, multi-agency 'target trial emulation' for the comparison of post-resuscitation epinephrine to norepinephrine.

INTRODUCTION: Epinephrine and norepinephrine are the two most commonly used prehospital vasopressors in the United States. Prior studies have suggested that use of a post-ROSC epinephrine infusion may be associated with increased rearrest and mortality in comparison to use of norepinephrine. We used target trial emulation methodology to compare the rates of rearrest and mortality between the groups of OHCA patients receiving these vasopressors in the prehospital setting. METHODS: Adult (18-80 years of age) non-traumatic OHCA patients in the 2018-2022 ESO Data Collaborative datasets with a documented post-ROSC norepinephrine or epinephrine infusion were included in this study. Logistic regression modeling was used to evaluate the association between vasopressor agent and outcome using two sets of covariables. The first set of covariables included standard Utstein factors, the dispatch to ROSC interval, the ROSC to vasopressor interval, and the follow-up interval. The second set added prehospital systolic blood pressure and SpO2 values. Kaplan-Meier time-to-event analysis was also conducted and the vasopressor groups were compared using a multivariable Cox regression model. RESULTS: Overall, 1,893 patients treated by 309 EMS agencies were eligible for analysis. 1,010 (53.4%) received an epinephrine infusion and 883 (46.7%) received a norepinephrine infusion as their initial vasopressor. Adjusted analyses did not discover an association between vasopressor agent and rearrest (aOR: 0.93 [0.72, 1.21]) or mortality (aOR: 1.00 [0.59, 1.69]). CONCLUSIONS: In this multi-agency target trial emulation, the use of a post-resuscitation epinephrine infusion was not associated with increased odds of rearrest in comparison to the use of a norepinephrine infusion.

The Current Discussion Regarding End-of-Life Care for Patients with Out-of-Hospital Cardiac Arrest with Initial Non-Shockable Rhythm: A Narrative Review.

Despite recent advances in resuscitation science, outcomes in patients with out-of-hospital cardiac arrest (OHCA) with initial non-shockable rhythm remains poor. Those with initial non-shockable rhythm have some epidemiological features, including the proportion of patients with a witnessed arrest, bystander cardiopulmonary resuscitation (CPR), age, and presumed etiology of cardiac arrest have been reported, which differ from those with initial shockable rhythm. The discussion regarding better end-of-life care for patients with OHCA is a major concern among citizens. As one of the efforts to avoid unwanted resuscitation, advance directive is recognized as a key intervention, safeguarding patient autonomy. However, several difficulties remain in enhancing the effective use of advance directives for patients with OHCA, including local regulation of their use, insufficient utilization of advance directives by emergency medical services at the scene, and a lack of established tools for discussing futility of resuscitation in advance care planning. In addition, prehospital termination of resuscitation is a common practice in many emergency medical service systems to assist clinicians in deciding whether to discontinue resuscitation. However, there are also several unresolved problems, including the feasibility of implementing the rules for several regions and potential missed survivors among candidates for prehospital termination of resuscitation. Further investigation to address these difficulties is warranted for better end-of-life care of patients with OHCA.

Could paramedics use the HEART Pathway to identify patients at low-risk of myocardial infarction in the prehospital setting?

In the Emergency Department, patients with suspected myocardial infarction can be risk stratified using the HEART pathway, which has recently been amended for prehospital use and modified for the incorporation of a high-sensitivity cardiac troponin test. In a prospective analysis, the performance of both HEART pathways in the prehospital setting, with a high-sensitivity cardiac troponin test using 3 different thresholds, was evaluated for major adverse cardiac events at 30 days. We found that both low-risk HEART pathways, when using the most conservative cardiac troponin thresholds, approached but did not reach accepted rule-out performance in the Emergency Department.

Time Is Life: Golden Ten Minutes on Scene-EuReCa_Serbia 2014-2023.

Background and Objectives: This study analyzed the frequency of factors influencing the course and outcomes of out-of-hospital cardiac arrest (OHCA) in Serbia and the prediction of pre-hospital outcomes and survival. Materials and Methods: Data were collected during the period from 1 October 2014, to 31 September 2023, according to the protocol of the EuReCa_One study (clinical trial ID number NCT02236819). Results: Overall 9303 OHCA events were registered with a median age of 71 (IQR 61-81) years and 59.7% of them being males. The annual OHCA incidence was 85.60 ± 20.73/100,000. Within all bystander-witnessed cases, bystander-initiated cardiopulmonary resuscitation in 15.3%. Within the resuscitation-initiated group, return-of-spontaneous circulation (ROSC) on scene (any ROSC) was present in 1037/4053 cases (25.6%) and ROSC on admission to the nearest hospital in 792/4053 cases (19.5%), while 201/4053 patients survived to hospital discharge (5.0%). Predictive potential on pre-hospital outcomes was shown by several factors. Also, of all patients having any ROSC, 89.2% were admitted to the hospital alive. The probability of any ROSC dropped below 50% after 17 min passed after the emergency call and 10 min after the EMS scene arrival. These time intervals were significantly associated with survival to hospital discharge (p < 0.001). Five-minute time intervals between both emergency calls and any ROSC and EMS scene arrival and any ROSC also had a significant predictive potential for survival to hospital discharge (p < 0.001, HR 1.573, 95% CI 1.303-1.899 and p = 0.017, HR 1.184, 95% CI 1.030-1.361, respectively). Conclusions: A 10-min time on scene to any ROSC is a crucial time-related factor for achieving any ROSC, and indirectly admission ROSC and survival to hospital discharge, and represents a golden time interval spent on scene in the management of OHCA patients. A similar effect has a time interval of 17 min from an emergency call. Further investigations should be focused on factors influencing these time intervals, especially time spent on scene.

Effect of a vapor barrier in combination with active external rewarming for cold-stressed patients in a prehospital setting: a randomized, crossover field study.

BACKGROUND: Use of a vapor barrier in the prehospital care of cold-stressed or hypothermic patients aims to reduce evaporative heat loss and accelerate rewarming. The application of a vapor barrier is recommended in various guidelines, along with both insulating and wind/waterproof layers and an active external rewarming device; however, evidence of its effect is limited. This study aimed to investigate the effect of using a vapor barrier as the inner layer in the recommended "burrito" model for wrapping hypothermic patients in the field. METHODS: In this, randomized, crossover field study, 16 healthy volunteers wearing wet clothing were subjected to a 30-minute cooling period in a snow chamber before being wrapped in a model including an active heating source either with (intervention) or without (control) a vapor barrier. The mean skin temperature, core temperature, and humidity in the model were measured, and the shivering intensity and thermal comfort were assessed using a subjective questionnaire. The mean skin temperature was the primary outcome, whereas humidity and thermal comfort were the secondary outcomes. Primary outcome data were analyzed using analysis of covariance (ANCOVA). RESULTS: We found a higher mean skin temperature in the intervention group than in the control group after approximately 25 min (p < 0.05), and this difference persisted for the rest of the 60-minute study period. The largest difference in mean skin temperature was 0.93 °C after 60 min. Humidity levels outside the vapor barrier were significantly higher in the control group than in the intervention group after 5 min. There were no significant differences in subjective comfort. However, there was a consistent trend toward increased comfort in the intervention group compared with the control group. CONCLUSIONS: The use of a vapor barrier as the innermost layer in combination with an active external heat source leads to higher mean skin rewarming rates in patients wearing wet clothing who are at risk of accidental hypothermia. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05779722.

Rapid Characterization of Undeclared Pharmaceuticals in Herbal Preparations by Ambient Ionization Mass Spectrometry for Emergency Care.

In Asia, some herbal preparations have been found to be adulterated with undeclared synthetic medicines to increase their therapeutic efficiency. Many of these adulterants were found to be toxic when overdosed and have been documented to bring about severe, even life-threatening acute poisoning events. The objective of this study is to develop a rapid and sensitive ambient ionization mass spectrometric platform to characterize the undeclared toxic adulterated ingredients in herbal preparations. Several common adulterants were spiked into different herbal preparations and human sera to simulate the clinical conditions of acute poisoning. They were then sampled with a metallic probe and analyzed by the thermal desorption-electrospray ionization mass spectrometry. The experimental parameters including sensitivity, specificity, accuracy, and turnaround time were prudently optimized in this study. Since tedious and time-consuming pretreatment of the sample is unnecessary, the toxic adulterants could be characterized within 60 s. The results can help emergency physicians to make clinical judgments and prescribe appropriate antidotes or supportive treatment in a time-sensitive manner.

Foreign body airway obstruction resulting in out-of-hospital cardiac arrest in Denmark - Incidence, survival and interventions.

BACKGROUND: Foreign body airway obstruction (FBAO) stands as an important contributor to accidental fatalities, yet prompt bystander interventions have been shown to improve survival. This study aimed to evaluate the incidence, interventions, and survival outcomes of patients with out-of-hospital cardiac arrest (OHCA) related to FBAO in comparison to patients with non-FBAO OHCA. METHODS: In this population-based cohort study, we included all OHCAs in Denmark from 2016 to 2022. Cases related to FBAO were identified and linked to the patient register. Descriptive and multivariable analyses were performed to evaluate prognostic factors potentially influencing survival. RESULTS: A total of 30,926 OHCA patients were included. The incidence rate of FBAO-related OHCA was 0.78 per 100,000 person-years. Among FBAO cases, 24% presented with return of spontaneous circulation upon arrival of the emergency medical services. The 30-day survival rate was higher in FBAO patients (30%) compared to non-FBAO patients (14%). Bystander interventions were recorded in 26% of FBAO cases. However, no statistically significant association between bystander interventions or EMS personnels' use of Magill forceps and survival was shown, aOR 1.47 (95 % CI 0.6-3.6) and aOR 0.88 (95% CI 0.3-2.1). CONCLUSION: FBAO-related OHCA was rare but has a higher initial survival rate than non-FBAO related OHCA, with a considerable proportion of patients achieving return of spontaneous circulation upon arrival of the emergency medical service personnel. No definitive associations were established between survival and specific interventions performed by bystanders or EMS personnel. These findings highlight the need for further research in this area.

Resuscitation (un-)wanted: Does anyone care? A retrospective real data analysis.

BACKGROUND AND OBJECTIVES: In case of out-of-hospital cardiac arrest (OHCA) personnel of the emergency medical services (EMS) are regularly confronted with advanced directives (AD) and do-not-attempt-resuscitation (DNACPR) orders. The authors conducted a retrospective analysis of EMS operation protocols to examine the prevalence of DNACPR in case of OHCA and the influence of a presented DNACPR on CPR-duration, performed Advanced-Life-Support (ALS) measures and decision making. MATERIALS AND METHODS: Retrospective analysis of prehospital medical documentation of all resuscitation incidents in a German county with 250,000 inhabitants from 1 January 2016 to 31 December 2022. Combined with data from the structured CPR team-feedback database patients characteristics, measures and course of the CPR were analysed. Statistic testing with significance level p < 0.05. RESULTS: In total n = 1,474 CPR events were analysed. Patients with DNACPR vs. no DNACPR: n = 263 (17.8%) vs. n = 1,211 (82.2%). Age: 80.0 ± 10.3 years vs. 68.0 ± 13.9 years; p < 0.001. Patients with ASA-status III/IV: n = 214 (81.3%) vs. n = 616 (50.9%); p < 0.001. Initial layperson-CPR: n = 148 (56.3%) vs. n = 647 (55.7%); p = 0.40. Airway management: n = 185 (70.3%) vs. n = 1,069 (88.3%); p < 0.001. With DNACPR CPR-duration initiated layperson-CPR vs. no layperson-CPR: 19:14 min (10:43-25:55 min) vs. 12:40 min (06:35-20:03 min); p < 0.001. CONCLUSION: In case of CPR EMS-personnel are often confronted with DNACPR-orders. Patients are older and have more previous diseases than patients without DNACPR. Initiated layperson-CPR might lead to misinterpretation of patients will with impact on CPR-duration and unwanted measures. Awareness of this issue should be created through measures such as training programs in particular to train staff in the interpretation and legal admissibility of ADs.

Predictive and protective factors for failing first pass intubation in prehospital rapid sequence intubation: an aetiology and risk systematic review with meta-analysis.

BACKGROUND: Prehospital rapid sequence intubation first pass success rates vary between 59% and 98%. Patient morbidity is associated with repeat intubation attempts. Understanding what influences first pass success can guide improvements in practice. We performed an aetiology and risk systematic review to answer the research question 'what factors are associated with success or failure at first attempt laryngoscopy in prehospital rapid sequence intubation?'. METHODS: MEDLINE, EMBASE, CINAHL, and Cochrane Library were searched on March 3, 2023 for studies examining first pass success rates for rapid sequence intubation of prehospital live patients. Screening was performed via Covidence, and data synthesised by meta-analysis. The review was registered with PROSPERO and performed and reported as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Reasonable evidence was discovered for predictive and protective factors for failure of first pass intubation. Predictive factors included age younger than 1 yr, the presence of blood or fluid in the airway, restricted jaw or neck movement, trauma patients, nighttime procedures, chronic or acute distortions of normal face/upper airway anatomy, and equipment issues. Protective factors included an experienced intubator, adequate training, use of certain videolaryngoscopes, elevating the patient on a stretcher in an inclined position, use of a bougie, and laryngeal manoeuvres. CONCLUSIONS: Managing bloody airways, positioning well, using videolaryngoscopes with bougies, and appropriate training should be further explored as opportunities for prehospital services to increase first pass success. Heterogeneity of studies limits stronger conclusions. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42022353609).

Implementing Tourniquet Conversion Guidelines for Civilian EMS and Prehospital Organizations : A Case Report and Review.

Since the first documented use of a tourniquet in 1674, the popularity of tourniquets has waxed and waned. During recent wars and more recently in Emergency Medical Services systems, the tourniquet has been proven to be a valuable tool in the treatment of life-threatening hemorrhage. However, tourniquet use is not without risk, and several studies have demonstrated adverse events and morbidity associated with tourniquet use in the prehospital setting, particularly when left in place for more than 2 h. Consequently, the US military's Committee on Tactical Combat Casualty Care has recommended guidelines for prehospital tourniquet conversion to reduce the risk of adverse events associated with tourniquets once the initial hemorrhage has been controlled. Emergency Medical Services systems that operate in rural, frontier, and austere environments, especially those with transport times to definitive care that routinely exceed 2 h, may consider implementing similar tourniquet conversion guidelines.

Optimal duration and timing of basic-life-support-only intervention for patients with out-of-hospital cardiac arrest.

To elucidate the relationship between the interval from cardiopulmonary resuscitation initiation to return of spontaneous circulation (ROSC) and neurologically favourable 1-month survival in order to determine the appropriate duration of basic life support (BLS) without advanced interventions. This population-based cohort study included patients aged ≥ 18 years with 9132 out-of-hospital cardiac arrest of presumed cardiac origin who were bystander-witnessed and had achieved ROSC between 2018 and 2020. Patients were classified into two groups based on the resuscitation methods as the "BLS-only" and the "BLS with administered epinephrine (BLS-AE)" groups. Receiver operating characteristic (ROC) curve analysis indicated that administering BLS for 9 min yielded the best neurologically outcome for patients with a shockable rhythm [sensitivity, 0.42; specificity, 0.27; area under the ROC curve (AUC), 0.60] in the BLS-only group. Contrastingly, for patients with a non-shockable rhythm, performing BLS for 6 min yielded the best neurologically outcome (sensitivity, 0.65; specificity, 0.43; AUC, 0.63). After propensity score matching, multivariate analysis revealed that BLS-only resuscitation [6.44 (5.34-7.77)] was associated with neurologically favourable 1-month survival. This retrospective study revealed that BLS-only intervention had a significant impact in the initial minutes following CPR initiation. Nevertheless, its effectiveness markedly declined thereafter. The optimal duration for effective BLS-only intervention varied depending on the patient's initial rhythm. Consequently, advanced interventions should be administered within the first few minutes to counteract the diminishing effectiveness of BLS-only intervention.