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).

Crystalloid Fluid Management of Non-Traumatic Hypotension by New South Wales Ambulance

INTRODUCTION

Shock is circulatory insufficiency, inadequate oxygen delivery, and cellular hypoxia. Intravenous fluids are essential for shock management. Despite treatment, patients can face persistent shock with ongoing hypotension, contributing to higher mortality. This analysis aims to quantify hypotensive non-traumatic cases in an Australian ambulance service, determine persistent hypotension prevalence, and assess paramedic-administered intravascular fluids' impact on blood pressure changes.

METHODS

This study is a retrospective analysis of prehospital fluid resuscitation by New South Wales Ambulance paramedics during 2022. Hypotension is defined as a systolic blood pressure of ≤ 90 mmHg, and persistent hypotension is a systolic blood pressure consistently below 90 mmHg across all observations, with a final blood pressure below 90 mmHg. This study aimed to determine the volume of fluid resuscitation at which a plateau in population-level systolic blood pressure response is observed, by calculating the derivative of the fitted logistic regression model. Moreover, this analysis identified the relative contribution of factors influencing the probability of an attempt at intravenous or intraosseous access using machine learning.

RESULTS

Among 796,865 attendances, 23,049 (2.9%) involved non-traumatic patients with hypotension. In total 7,388 (32.1%) of the hypotensive cases resulted in persistent hypotension, of which 3,235 (43.8%) received Hartmann's solution and 1,745 (53.9%) received at least 500 ml of fluids but still had hypotension. The model showed that systolic blood pressure tends to stop increasing after 500-600 milliliters of fluid are given. This suggests that, on average, giving more fluid than this may not raise blood pressure further in a prehospital setting, though individual patient needs can differ. The top four factors from the machine learning shows that as initial respiratory rate goes up, the probability of intravascular access rises. Transport times less than 20 min are associated with a smaller chance of access and younger patients are less likely to receive an attempt. Finally, extremes of systolic blood pressure are more likely to receive access attempts.

CONCLUSION

This study found that three percent of non-traumatic attendances have at least one episode of hypotension, and that more than half of these have persistent hypotension. Only 44% of persistently hypotensive received fluids, and half of persistently hypotensive patients stayed hypotensive despite a reasonable volume of prehospital crystalloids.

A randomized trial of expedited intra-arrest transfer versus more extended on-scene resuscitation for refractory out of hospital cardiac arrest: Rationale and design of the EVIDENCE trial

BACKGROUND

Refractory Out of Hospital Cardiac Arrest (r-OHCA) is common and the benefit versus harm of intra-arrest transport of patients to hospital is not clear.

OBJECTIVE

To assess the rate of survival to hospital discharge in adult patients with r-OHCA, initial rhythm pulseless ventricular tachycardia (VT)/ventricular fibrillation (VF) or Pulseless Electrical Activity (PEA) treated with 1 of 2 locally accepted standards of care:1 expedited transport from scene; or2 ongoing advanced life support (ALS) resuscitation on-scene.

HYPOTHESIS

We hypothesize that expedited transport from scene in r-OHCA improves survival with favorable neurological status/outcome.

METHODS/DESIGN

Phase III, multi-center, partially blinded, prospective, intention-to-treat, safety and efficacy clinical trial with contemporaneous registry of patient ineligible for the clinical trial. Eligible patients for inclusion are adults with witnessed r-OHCA; estimated age 18 to 70, assumed medical cause with immediate bystander cardiopulmonary resuscitation (CPR); initial rhythm of VF/pulseless VT, or PEA; no return of spontaneous circulation following 3 shocks and/or 15 minutes of professional on-scene resuscitation; with mechanical CPR available. Two hundred patients will be randomized in a 1:1 ratio to either expedited transport from scene or ongoing ALS at the scene of cardiac arrest.

SETTING

Two urban regions in NSW Australia.

OUTCOMES

Primary: survival to hospital discharge with cerebral performance category (CPC) 1 or 2. Secondary: safety, survival, prognostic factors, use of ECMO supported CPR and functional assessment at hospital discharge and 4 weeks and 6 months, quality of life, healthcare use and cost-effectiveness.

CONCLUSIONS

The EVIDENCE trial will determine the potential risks and benefits of an expedited transport from scene of cardiac arrest.

Prehospital times and outcomes of patients transported using an ambulance trauma transport protocol: A data linkage analysis from New South Wales Australia

INTRODUCTION

Prehospital trauma systems are designed to ensure optimal survival from critical injuries by triaging and transporting such patients to the most appropriate hospital in a timely manner.

OBJECTIVES

We sought to evaluate whether prehospital time and location (metropolitan versus non-metropolitan) were associated with 30-day mortality in a cohort of patients transported by road ambulance using a trauma transport protocol.

METHODS

Data linkage analysis of routinely collected ambulance and hospital data across all public hospitals in New South Wales (NSW). The data linkage cohort included adult patients (age ≥ 16years) transported by NSW Ambulance, where a T1 Major Trauma Transport Protocol was documented by paramedic crews and transported by road to a public hospital emergency department in NSW for two years between January 2019 and December 2020. The outcomes of interest were prehospital times (response time, scene time and transport time) and 30-day mortality due to injury.

RESULTS

9012 cases were identified who were transported to an emergency department with T1 protocol indication. Median prehospital transport times were longer in non-metropolitan road transports [n = 3,071, 98 min (71-126)] compared to metropolitan transports [n = 5,941, 65 min (53-80), p < 0.001]. There was no significant difference in 30-day mortality between the two groups (1.24% vs 1.65%, p = 0.13). In the subgroup of patients with abnormal vital signs, the only predictors of mortality were increasing age, presence of severe injury (OR 24.87, 95%CI 11.02, 56.15, p < 0.001), and arrival at a non-trauma facility (OR 3.01, 95%CI 1.26, 7.20, p < 0.05). Increasing transport times were not found to increase the odds of 30-day mortality.

DISCUSSION

In the context of an inclusive trauma system and an established prehospital major trauma protocol, increasing prehospital transport times and scene location were not associated with increased mortality.

Evaluation of the New South Wales ambulance T1 major trauma transport protocol: A state-wide data linkage study

INTRODUCTION

Prehospital triage and transport protocols are critical components of the trauma systems. Still, there have been limited studies evaluating the performance of trauma protocols in New South Wales, such as the NSW ambulance major Trauma transport protocol (T1).

OBJECTIVES

Determine the performance of a major trauma transport protocol in a cohort of ambulance road transports METHODS: A data-linkage study using routine ambulance and hospital datasets across New South Wales Australia. Adult patients (age > 16 years) where any trauma protocol was indicated by paramedic crews and transported to any emergency department in the state were included. Major injury outcome was defined as an Injury Severity Score >8 based on coded in-patient diagnoses, or admission to intensive care unit or death within 30 days due to injury. Multivariable logistic regression was used to determine ambulance predictors of major injury outcome.

RESULTS

There were 168,452 linked ambulance transports analysed. Of the 9,012 T1 protocol activations, 2,443 cases had major injury [positive predictive value (PPV) = 27.1%]. There were 16,823 major injuries in total giving a sensitivity of the T1 protocol of 2,443/16,823 (14.5%), specificity of 145,060/151,629 (95.7%) and a negative predictive value (NPV) of 145,060/159,440 (91%). Overtriage rate associated with T1 protocol was 5,697/9,012 (63.2%) and undertriage rate was 5,509/159,440 (3.5%). The most important predictor of major injury was the activation of more than one trauma protocol by ambulance paramedics.

DISCUSSION

Overall, the T1 was associated with low undertriage and high specificity. The protocol may be improved by considering age and the number of trauma protocols activated by paramedics for any given patient.

The New South Wales Sudden Cardiac Arrest Registry: A Data Linkage Cohort Study

BACKGROUND

Sudden cardiac arrest (SCA) in young people aged 1 to 50 years often occurs with no presenting symptoms or risk factors prompting screening for cardiovascular disease prior to their cardiac arrest. Approximately 3,000 young Australians suffer from sudden cardiac death (SCD) each year, making this a major public health issue. However, there is significant variation in the way incidence is estimated resulting in discrepancy across reporting which impacts our ability to understand and prevent these devastating events. We describe the New South Wales (NSW) Sudden Cardiac Arrest Registry: a retrospective, data linkage study which will identify all SCAs in the young in NSW from 2009 through to June 2022.

OBJECTIVE

To determine the incidence, demographic characteristics and causes of SCA in young people. We will develop an NSW-based registry that will contribute to a greater understanding of SCA including risk factors and outcomes.

METHODS

The cohort will include all people who experience a SCA in the NSW community aged between 1 to 50 years. Cases will be identified using the following three datasets: the Out of Hospital Cardiac Arrest Register housed at NSW Ambulance, the NSW Emergency Department Data Collection, and the National Coronial Information System. Data from eight datasets will be collected, anonymised and linked for the entire cohort. Analysis will be undertaken and reported using descriptive statistics.

CONCLUSIONS

The NSW SCA registry will be an important resource for the improved understanding of SCA and inform the widespread impacts it has on individuals, their families and society.

The Hunter-8 scale prehospital triage workflow for identification of large vessel occlusion and brain haemorrhage

ObjectiveThe Hunter-8 prehospital stroke scale predicts large vessel occlusion in hyperacute ischemic stroke patients (LVO) at hospital admission. We wished to test its performance in the hands of paramedics as part of a prehospital triage algorithm. We aimed to determine a) the proportion of patients identified by the Hunter-8 algorithm, receiving reperfusion therapies, b) whether a call to stroke team improved this, and c) performance for LVO detection using an expanded LVO definition.MethodsA prehospital workflow combining pre-morbid functional status, time from symptom onset, and the Hunter-8 scale was implemented from July 2019. A telephone call to the stroke team was prompted for potential treatment candidates. Classic LVO was defined as a proximal middle cerebral artery (MCA-M1), terminal internal carotid artery, or tandem occlusion. Extended LVO added proximal MCA-M2 and basilar occlusions.ResultsFrom July 2019 to April 2021, there were 363 Hunter-8 activations, 320 analysed: 181 (56.6%) had confirmed ischemic strokes, 13 (4.1%) transient ischemic attack, 91 (28.5%) stroke mimics, and 35 (10.9%) intracranial haemorrhage. Fifty-two patients (16.3%) received reperfusion therapies, 35 with Hunter-8 ≥ 8. The stroke doctor changed the final destination for 76 patients (23.7%), and five received reperfusion therapies. The AUCs for classic and extended LVO were 0.73 (95% CI 0.66-0.79) and 0.72 (95% CI 0.65-0.77), respectively.ConclusionThe Hunter-8 workflow resulted in 28.7% of confirmed ischemic stroke patients receiving reperfusion therapies, with no secondary transfers to the comprehensive stroke centre. The role of communication with stroke team needs to be further explored.

Duration of cooling with water for thermal burns as a first aid intervention: A systematic review

BACKGROUND

Cooling thermal burns with running water is a recommended first aid intervention. However, guidance on the ideal duration of cooling remains controversial and inconsistent across organisations.

AIM

To perform a systematic review of the evidence for the question; Among adults and children with thermal burn, does active cooling using running water as an immediate first aid intervention for 20 min or more, compared with active cooling using running water for any other duration, change the outcomes of burn size, burn depth, pain, adverse outcome (hypothermia) or complications?

METHOD

We searched Medline, Embase, Cochrane Database of Systematic Reviews and used ROBINS-I to assess for risk of bias. We used Grading of Recommendations, Assessment, Development and Evaluation methodology for determining the certainty of evidence. We included all studies that compared the selected outcomes of the duration of cooling of thermal burns with water in all patient ages. (PROSPERO registration number: CRD42021180665). From 560 screened references, we included four observational studies. In these studies, 48% of burns were cooled for 20 min or more. We found no benefit for a duration of 20 min or more of cooling when compared with less than 20 min of cooling for the outcomes of size and depth of burn, re-epithelialization, or skin grafting. The evidence is of very low certainty owing to limitations in study design, risk of bias and indirectness.

CONCLUSION

The optimal duration of cooling for thermal burns remains unknown and future prospective research is indicated to better define this treatment recommendation.

2019 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.

'Popping nana back into bed' - a qualitative exploration of paramedic decision making when caring for older people who have fallen

BACKGROUND

Older fallers constitute a large proportion of ambulance work, and as many as 25% are not transported to hospital following paramedic assessment. The objective of this study was to explore the decision making process used by paramedics when caring for older fallers.

METHODS

A qualitative study was conducted using constructivist grounded theory methodology. Purposive sampling was used to recruit paramedics to participate in semi-structured interviews and focus groups. Data analysis commenced with line-by-line coding, developing into formation of theoretical categories. Theoretical sampling was then used to clarify emerging theoretical concepts, with data collection and analysis continuing until theoretical saturation was achieved.

RESULTS

A total of 33 paramedics participated in 13 interviews and 4 focus groups. When caring for older fallers, paramedic decision making is profoundly affected by 'role perception', in which the individual paramedic's perception of what the role of a paramedic is determines the nature of the decision making process. Transport decisions are heavily influenced by a sense of 'personal protection', or their confidence in the ambulance service supporting their decisions. 'Education and training' impacts on decision making capacity, and the nature of that training subliminally contributes to role perception. Role perception influences the sense of legitimacy a paramedic attaches to cases involving older fallers, impacting on patient assessment routines and the quality of subsequent decisions.

CONCLUSIONS

Paramedic decision making processes when caring for older people who have fallen appear to be strongly influenced by their perception of what their role should be, and the perceived legitimacy of incidents involving older fallers as constituting 'real' paramedic work.

A multidisciplinary intervention to prevent subsequent falls and health service use following fall-related paramedic care: a randomised controlled trial

Background

approximately 25% of older people who fall and receive paramedic care are not subsequently transported to an emergency department (ED). These people are at high risk of future falls, unplanned healthcare use and poor health outcomes.

Objective

to evaluate the impact of a fall-risk assessment and tailored fall prevention interventions among older community-dwellers not transported to ED following a fall on subsequent falls and health service use.

Design, setting, participants

Randomised controlled trial involving 221 non-transported older fallers from Sydney, Australia.

Intervention

the intervention targeted identified risk factors and used existing services to implement physiotherapy, occupational therapy, geriatric assessment, optometry and medication management interventions as appropriate. The control group received individualised written fall prevention advice.

Measurements

primary outcome measures were rates of falls and injurious falls. Secondary outcome measures were ambulance re-attendance, ED presentation, hospitalisation and quality of life over 12 months. Analysis was by intention-to-treat and per-protocol according to self-reported adherence using negative binominal regression and multivariate analysis.

Results

ITT analysis showed no significant difference between groups in subsequent falls, injurious falls and health service use. The per-protocol analyses revealed that the intervention participants who adhered to the recommended interventions had significantly lower rates of falls compared to non-adherers (IRR: 0.53 (95% CI : 0.32-0.87)).

Conclusion

a multidisciplinary intervention did not prevent falls in older people who received paramedic care but were not transported to ED. However the intervention was effective in those who adhered to the recommendations.

Trial registration

the trial is registered at the Australian New Zealand Clinical Trials Registry: ACTRN 12611000503921, 13/05/2011.

The influence of paramedic and patient gender on the administration of analgesics in the out-of-hospital setting

OBJECTIVE

To determine whether analgesic administration in the out-of-hospital setting is influenced by the gender of the patient or the gender of the paramedic.

METHODS

This retrospective cohort study of patient care records included adult patients (age > 15 years) with moderate to severe pain (verbal numerical rating score 4-10) treated by paramedics between January 1, 2008 and December 31, 2009. Data extracted included patient pain severity score, analgesia provided by paramedics, and gender of the treating paramedic. Data was analyzed by descriptive statistics, χ(2) test, and logistic regression. The primary outcome measures were the effect of patient and paramedic gender on analgesic administration.

RESULTS

The study population comprised 42,051 patients, median age of 57 years (38-75); 50.4% were female and 51% were administered an analgesic agent. For the outcome of receiving any analgesia, neither patient gender nor paramedic gender was predictive (p = NS). In a multivariate model for the outcome of receiving any analgesia, patient gender, paramedic gender, and the interaction between patient and paramedic gender were all nonsignificant (p = NS). For the outcome of receiving opioid analgesia (i.e., morphine or fentanyl), male patients were at greater odds of receiving an opioid (OR 1.52, 95% CI 1.29-1.79, p < 0.0001). Paramedic gender was not predictive of whether an opioid was given (p = NS).

CONCLUSIONS

The gender of the paramedic did not appear to influence the odds of analgesic administration. Female patients were less likely to receive opioids. Paramedic gender does not explain this finding.

Airways in out-of-hospital cardiac arrest: systematic review and meta-analysis

OBJECTIVE

To determine the differences in survival for out-of-hospital advanced airway intervention (AAI) compared with basic airway intervention (BAI) in cardiac arrest.

BACKGROUND

AAI is commonly utilized in cardiac arrest in the out-of-hospital setting as a means to secure the airway. Observational studies and clinical trials of AAI suggest that AAI is associated with worse outcomes in terms of survival. No controlled trials exist that compares AAI to BAI.

METHODS

We conducted a bias-adjusted meta-analysis on 17 observational studies. The outcomes were survival, short-term (return of spontaneous circulation and to hospital admission), and longer-term (to discharge, to one month survival). We undertook sensitivity analyses by analyzing patients separately: those who were 16 years and older, nontrauma only, and attempted versus successful AAI.

RESULTS

This meta-analysis included 388,878 patients. The short-term survival for AAI compared to BAI were overall OR 0.84(95% CI 0.62 to 1.13), for endotracheal intubation (ETI) OR 0.79 (95% CI 0.54 to 1.16), and for supraglottic airways (SGA) OR 0.59 (95% CI 0.39 to 0.89). Long-term survival for AAI were overall OR 0.49 (95% CI 0.37 to 0.65), for ETI OR 0.48 (95% CI 0.36 to 0.64), and for SGA OR 0.35 (95% CI 0.28 to 0.44). Sensitivity analyses shows that limiting analyses to adults, non-trauma victims, and instances where AAI was both attempted and successful did not alter results meaningfully. A third of all studies did not adjust for any other confounding factors that could impact on survival.

CONCLUSIONS

This meta-analysis shows decreased survival for AAIs used out-of-hospital in cardiac arrest, but are likely biased due to confounding, especially confounding by indication. A properly conducted prospective study or a controlled trial is urgently needed and are possible to do.

No beneficial effects of levosimendan in acute porcine endotoxaemia

BACKGROUND

Levosimendan has been proposed as an attractive alternative to adrenergic agents for the treatment of sepsis-induced heart failure and haemodynamic derangements. Its use in this setting is, however, still not well investigated. The aim of this study was to test the hypothesis that levosimendan is able to attenuate endotoxin-induced pulmonary hypertension and improve myocardial function in a porcine model. The secondary aims were to investigate its effect on renal and liver function, and the plasma cytokine response.

METHODS

Endotoxaemia was induced in 18 pigs, randomized to placebo and Levosimendan groups. All pigs were fluid resuscitated and Noradrenalin infusion was given according to a predefined protocol. Systemic haemodynamics and myocardial function were measured using pulmonary artery catheterization and transthoracic echocardiography. Renal and liver function tests and cytokine concentrations were measured in plasma.

RESULTS

Levosimendan did not attenuate endotoxin-induced pulmonary hypertension and did not improve myocardial function. There were no differences in renal or liver function. Increases in arterial lactate and decreases in base excess were observed in the Levosimendan group, as well as significant increases in plasma interleukin (IL)-6 and IL-8.

CONCLUSIONS

Contrary to our hypothesis, levosimendan given in conjunction with a protocolized vasopressor and fluid resuscitation did not improve cardiac, renal or liver function in this model of acute porcine endotoxaemia. Hyperlactataemia, acidosis and increases in plasma pro-inflammatory cytokines were observed, the mechanisms and implications of which remain unclear.

The provision of Ambulance Services in Australia: a legal argument for the national registration of paramedics

This paper identifies that there is a growing private ambulance sector, notwithstanding legislative prohibitions on the provision of ambulance services that exist in nearly all Australian State and Territories. Notwithstanding these prohibitions, there appears to be no intention to prosecute private ambulance providers and, indeed, governments probably appreciate that these services fill a need and reduce the demand for non-emergency services on state run ambulance services. The paper will define what is meant by ambulance services and describes what is prohibited in each Australian jurisdiction and then argue that, to ensure that the providers of ambulance services continue to deliver a quality service to the public, there should be a legally sanctioned system to register paramedics and the use of various titles associated with the prehospital sector must be restricted.