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).

Endotracheal Tube Intracuff Pressure Changes in Patients Transported by a Helicopter Emergency Medical Service: A Prospective Observational Study.

OBJECTIVE: The pressure within an endotracheal tube cuff is of particular importance in helicopter emergency medical services (HEMS) transport because the unpressurized cabin is subjected to decreases in atmospheric pressure. This can cause the cuff to overinflate and may be associated with clinical complications. We sought to evaluate endotracheal tube cuff pressure changes among intubated patients during HEMS transport. METHODS: A prospective observational study was performed including adult patients who were intubated and transported by helicopter between April 2017 and October 2018. Cuff pressures were measured before, during, and after HEMS transport with a commercial manometer. RESULTS: A total of 208 patients were included. The median maximum flight altitude was 3,000 (interquartile range [IQR], 2,000-5,000) ft. The median initial cuff pressure before takeoff was 35 (IQR, 24-50) cm H2O, which increased to 50 (IQR, 35-70) cm H2O at maximum altitude. A total of 169 (81.3%) patients had a cuff pressure > 30 cm H2O at maximum altitude. There was a moderate correlation between altitude and cuff pressure (r = 0.532, P < .001). CONCLUSIONS: Cuff pressure increased during HEMS transport, demonstrating the need for routine cuff pressure monitoring during flight. Further research is required to determine if exposure to transient increases in cuff pressure for short durations is clinically significant.

Prehospital Rapid Sequence Intubation by Intensive Care Flight Paramedics.

OBJECTIVE: Rapid sequence intubation (RSI) is an advanced airway procedure for critically ill or injured patients. Paramedic-performed RSI in the prehospital setting remains controversial, as unsuccessful or poorly conducted RSI is known to result in significant complications. In Victoria, intensive care flight paramedics (ICFPs) have a broad scope of practice including RSI in both the adult and pediatric population. We sought to describe the success rates and characteristics of patients undergoing RSI by ICFPs in Victoria, Australia. METHODS: A retrospective data review was conducted of adult (≥ 16 years) patients who underwent RSI by an ICFP between January 1, 2011, and December 31, 2016. Data were sourced from the Ambulance Victoria data warehouse. RESULTS: A total of 795 cases were included in analyses, with a mean age of 45 (standard deviation = 19.6) years. The majority of cases involved trauma (71.7%), and most patients were male (70.1%). Neurological pathologies were the most common clinical indication for RSI (68.3%). The first pass success rate of intubation was 89.4%, and the overall success rate was 99.4%. Of the 5 failed intubations (0.6%), all patients were safely returned to spontaneous respiration. Two patients were returned via bag/valve/mask (BVM) support alone, two with BVM and oropharyngeal airway, and one via supraglottic airway. No surgical airways were required. Overall, we observed transient cases of hypotension (5.2%), hypoxemia (1.3%), or both (0.1%) in 6.6% of cases during the RSI procedure. CONCLUSION: A very high RSI procedural success rate was observed across the study period. This supports the growing recognition that appropriately trained paramedics can perform RSI safely in the prehospital environment.

Educational standards for training paramedics in ultrasound: a scoping review.

BACKGROUND: Paramedic-performed out-of-hospital ultrasound is a novel skill that has gained popularity in some services in recent years. In this setting point-of care ultrasound (POCUS) can provide additional information that can assist with management and guide transport to the most appropriate facility. We sought to explore the different educational approaches used for training paramedics in ultrasound in the out-of-hospital setting. METHODS: Ovid MEDLINE, EMBASE, EBM Reviews, The Cochrane Library, CINAHL plus, The Monash University Research Repository and the British Thesis Library were searched from the 1st of January 1990 to the 6th of April 2016. Google Scholar was searched and reference lists of relevant papers were examined to identify additional studies. Articles were included if they reported on out-of-hospital and POCUS educational approaches for paramedics. RESULTS: A total of 2002 unique articles were identified of which 18 articles met the inclusion criteria. Most articles reported combined cohorts of emergency providers with varying years of experience though most operators were POCUS naïve. The most common clinical assessment for which paramedic POCUS curricula was described was the focused assessment sonography for trauma (FAST) examination. Education programs varied from two-minutes to two-days with all studies including both didactic and practical training. CONCLUSION: Education programs for POCUS for paramedics vary considerably, and do not appear to align with qualification level or clinical experience. Further research investigating education and subsequent clinical application of POCUS by paramedics is required, as well as prospective, outcome based studies in order to measure the clinical utility of out-of-hospital POCUS.

Endotracheal Cuff Pressure Changes During Helicopter Transport: A Systematic Review.

OBJECTIVE: Cuff pressures are important in ventilated patients undergoing helicopter transport. An altitude-related increase in endotracheal tube (ETT) intracuff pressure has been shown in simulated hypobaric environments, model tracheas, and animal studies and may not accurately reflect in vivo pressures. The aim of this study was to determine if ETT intracuff pressure increases above the critical perfusion pressure of the trachea in ventilated patients during helicopter transport. METHODS: Ovid Medline, CINAHL, Embase, Scopus, and the Cochrane Library were searched from their commencement to January 29, 2016. Google Scholar was searched, and reference lists of relevant articles were examined to identify additional studies. Articles were included if they reported on ETT intracuff pressure in ventilated patients during helicopter emergency medical service transport. RESULTS: A total of 330 articles were identified; only 2 prospective observational studies met the inclusion criteria. The studies reported a mean cuff pressure increase of 23 cm H2O and 33.9 cm H2O. Both studies reported ETT intracuff pressure to frequently exceed the critical perfusion pressure of the tracheal mucosa during helicopter transport. CONCLUSION: Further research with longitudinal follow-up is required to confirm these findings to determine if the effects of transient increased ETT intracuff pressure are clinically significant.

Characteristics of Fixed Wing Air Ambulance Transports in Victoria, Australia.

OBJECTIVE: Air medical transport is important for the transfer of patients in the prehospital and interhospital environment. Few studies have described the services provided by fixed wing ambulances or the broader clinical profiles of patients they transport. Such information may be useful for the planning and allocation of resources, assistance with training, and refining clinical protocols. We sought to describe the characteristics of patients transported by fixed wing aircraft at Air Ambulance Victoria (AAV) and the service AAV provides in Victoria, Australia. METHODS: A retrospective data review of patients transported by AAV fixed wing aircraft between January 1, 2011, and June 30, 2015, was performed. Data were sourced from the Ambulance Victoria data warehouse. Retrievals involving physicians were excluded. RESULTS: A total of 16,579 patients were transported during the study period, with a median age of 66 years. Most patients were male (58.7%), and cardiovascular/hematologic conditions (27.2%) were most common. Overall, 51.7% of cases were prebooked routine transfers, 47.4% were interhospital routine transfers, and 0.9% were primary responses. Caseloads were largest in the regions furthest from the capital city. CONCLUSION: The AAV fixed wing service in Victoria enables regional and remote patients to be transported to definitive care without major disruption to ground ambulances.

Pediatric Distraction Tools for Prehospital Care of Pain and Distress: A Systematic Review.

CONTEXT: Distraction therapies are widely used in emergency departments to manage pediatric pain and distress. Little is known about which distraction techniques would translate best into the prehospital environment. OBJECTIVE: To identify emergency department-based distraction techniques for managing pain and/or distress in pediatric patients who may be suitable for the prehospital environment. DATA SOURCES: Ovid Medline, Embase, CINAHL, Cochrane library, World Health Organization Clinical Trials Registry and Google Scholar were searched from their beginning to May 2022. STUDY SELECTION: Studies were included if they reported on: (1) distraction techniques, (2) pediatric ED patients, (3) with pain and/or distress, and (4) used interventional or observational study designs. Studies utilizing interventions not feasible in the prehospital setting were excluded. DATA EXTRACTION: Three authors independently assessed eligibility and completed data extraction. RESULTS: The search yielded 4516 records, and 29 studies were included. Risk of bias across all studies was moderate to high. Children were 3 months to 18 years old. Digital, nondigital, and environmental distractors were tested using 12 pain and 15 distress measurement tools. No significant negative outcomes were reported. Fifteen studies reported reductions in self-reported pain and/or distress. Active, nondigital distractors most consistently reduced pain. There was insufficient evidence to support a distraction type for distress. LIMITATIONS: The heterogeneity in study design, distractors, measurement tools, and reporting restricted statistical analysis. CONCLUSIONS: Distraction tools that effectively reduce pediatric pain and/or distress in the ED exist and could be adapted to the prehospital environment. Further research is required to determine feasibility and effectiveness.

Needle Cricothyroidotomy by Intensive Care Paramedics.

OBJECTIVE: Cricothyroidotomy is an advanced airway procedure for critically ill or injured patients. In Victoria, Australia, intensive care paramedics (ICPs) perform needle cricothyroidotomy utilizing the proprietary QuickTrach II (QTII) device. Recently, an Ambulance Victoria (AV) institutional change in workflow included pre-puncture surgical incision to assist in successful placement. This review aims to explore whether a surgical pre-incision prior to the insertion of the device improved overall procedural success rates of needle cricothyroidotomy using the QTII. METHODS: This was a retrospective review of all patients who received a needle cricothyroidotomy by ICPs from May 1, 2015 through September 15, 2020. Data and patient care records were sourced from the AV data warehouse. RESULTS: A total of 27 patients underwent a needle cricothyroidotomy with the mean age of patients being 50.2 years. Most cricothyroidotomies were performed using the QuickTrach II kit (92.6%). Prior to modification of the QTII procedure, front-of-neck access (FONA) success was 50.0%; however, this improved to 82.4% after the procedures recent update. The overall success rate of all paramedic-performed needle cricothyroidotomy during the study period was 74.1% (n = 20). CONCLUSIONS: This review demonstrates that propriety devices such as the QTII device achieve a low success rate for a FONA intervention. Despite the low frequency of this procedure, ICPs with extensive training and regular maintenance can perform needle cricothyroidotomy using scalpel assistance with a reasonable success rate. But when compared to the broader literature, success rate using a more straightforward technique such as a surgical cricothyroidotomy technique is likely going to be higher.

Use of intramuscular ketamine by paramedics in the management of severely agitated patients.

OBJECTIVE: Administration of a sedative agent is required for safe transport of prehospital patients with severe agitation to EDs. Ambulance services in Australasia use ketamine, droperidol or midazolam as first line agent but the optimal agent is uncertain. In Victoria, intramuscular (IM) ketamine is used. The present study aimed to examine the prehospital characteristics and ED outcomes of patients with severe agitation after IM ketamine administration. METHODS: A retrospective review was conducted for patients who received IM ketamine for severe agitation over a 2-year period. Data were sourced from Ambulance Victoria and linked to hospital data. The primary outcome was time to sedation. Data collected included baseline characteristics, adverse events and ED outcomes. RESULTS: Three hundred and fifty-eight prehospital cases transported to 32 hospitals were included. Outcome data were available for 305 patients (21 hospitals). Median age was 31 years (IQR 23-40). 71.2% were male. Adequate sedation was achieved in 96.9% of cases in a median time of 5.0 min (IQR 3.0-7.0; range 1-31 min). Adverse events were transient hypoxia (5.0%), hyper-salivation (4.2%) and emergence reactions (0.8%). A total of 45 (14.8%) patients were intubated; two prehospital. CONCLUSION: Intramuscular ketamine is effective with a low rate of prehospital complications in severely agitated patients in the prehospital setting. Given the variation in ambulance practice in Australasia, prospective, randomised trials in the prehospital setting comparing ketamine to other sedating agents such as droperidol in patients with severe agitation are required.

Double sequential external defibrillation for refractory ventricular fibrillation out-of-hospital cardiac arrest: A systematic review and meta-analysis.

BACKGROUND: Double sequential external defibrillation (DSED) is a novel intervention which has shown potential in the management of refractory ventricular fibrillation (VF). This review aims to identify the literature surrounding the use of DSED in out-of-hospital refractory VF and assess whether this intervention improves survival outcomes. METHODS: The databases Ovid Medline, EMBASE, CINAHL, SCOPUS and the Cochrane Library were searched from their commencement to January 29th 2018. Google (scholar) was also searched for grey literature. We combined MeSH terms and text words for DSED in refractory VF and included studies that used an interventional or observational design. Study quality was assessed using the Newcastle-Ottawa Scale. A random effects model using the DerSimonian & Laird method was used to calculate pooled ORs and 95% CIs. RESULTS: The search yielded 5351 unique records, of which two retrospective studies met the eligibility criteria. No randomised controlled trials were identified. The pooled population included 499 patients of which 19% (n = 95) received DSED and 81% (n = 404) were managed with standard resuscitation protocols. Confirmation of DSED was self-reported by paramedics. Neither study adjusted for confounding factors or baseline characteristics across the study groups. The definition of refractory VF and the protocol for DSED use differed across studies. Over half of cases were witnessed cardiac arrests (58.7%, n = 293) and bystander CPR was initiated in 53.3% (n = 266) of cases. In the meta-analysis, DSED had no effect on survival to hospital discharge (OR 0.69, 95% CI: 0.30, 1.60), event survival (OR 0.98, CI: 0.59, 1.62) or ROSC (OR 0.86, 95% CI: 0.49-1.48). CONCLUSION: The effectiveness of DSED remains unclear. Further well-designed prospective studies are needed to determine whether DSED has a role in the treatment of refractory VF.