Inhaled analgesics for the treatment of prehospital acute pain-A systematic review.

BACKGROUND: Many prehospital emergency patients receive suboptimal treatment for their moderate to severe pain. Various factors may contribute. We aim to systematically review literature pertaining to prehospital emergency adult patients with acute pain and the pain-reducing effects, adverse events (AEs), and safety issues associated with inhaled analgetic agents compared with other prehospital analgesic agents. METHODS: As part of an initiative from the Scandinavian Society of Anaesthesia and Intensive Care Medicine, we conducted a systematic review (PROSPERO CRD42018114399), applying the PRISMA guidelines, Grading of Recommendations Assessment, Development, and Evaluation (GRADE), and Cochrane methods, searching the Cochrane Library, Epistemonikos, Centre for Reviews and Dissemination, PubMed, and EMBASE databases (updated March 2024). Inclusion criteria were the use of inhaled analgesic agents in adult patients with acute pain in the prehospital emergency care setting. All steps were performed by minimum of two individual researchers. The primary outcome was pain reduction; secondary outcomes were speed of onset, duration of effect, and relevant AEs. RESULTS: We included seven studies (56,535 patients in total) that compared inhaled agents (methoxyflurane [MF] and nitrous oxide [N2O]) to other drugs or placebo. Study designs were randomized controlled trial (1; n = 60), randomized non-blinded study (1; n = 343), and randomized open-label study (1; n = 270). The remaining were prospective or retrospective observational studies. The evidence according to GRADE was of low or very low quality. No combined meta-analysis was possible. N2O may reduce pain compared to placebo, but not compared to intravenous (IV) paracetamol, and may be less effective compared to morphine and MF. MF may reduce pain compared to paracetamol, ketoprofen, tramadol, and fentanyl. Both agents may be associated with marked but primarily mild AEs. CONCLUSION: We found low-quality evidence suggesting that both MF and N2O are safe and may have a role in the management of pain in the prehospital setting. There is low-quality evidence to support MF as a short-acting single analgesic or as a bridge to IV access and the administration of other analgesics. There may be occupational health issues regarding the prehospital use of N2O.

Femoral nerve blocks for the treatment of acute pre-hospital pain: A systematic review with meta-analysis.

BACKGROUND: Pain management is one of the most important interventions in the emergency medical services. The femoral nerve block (FNB) is, among other things, indicated for pre- and post-operative pain management for patients with femoral fractures but its role in the pre-hospital setting has not been determined. The aim of this review was to assess the effect and safety of the FNB in comparison to other forms of analgesia (or no treatment) for managing acute lower extremity pain in adult patients in the pre-hospital setting. METHODS: A systematic review (PROSPERO registration (CRD42018114399)) was conducted. The Cochrane and GRADE methods were used to assess outcomes. Two authors independently reviewed each study for eligibility, extracted the data and performed risk of bias assessments. RESULTS: Four studies with a total of 252 patients were included. Two RCTs (114 patients) showed that FNB may reduce pain more effectively than metamizole (mean difference 32 mm on a 100 mm VAS (95% CI 24 to 40)). One RCT (48 patients) compared the FNB with lidocaine and magnesium sulphate to FNB with lidocaine alone and was only included here for information regarding adverse effects. One case series included 90 patients. Few adverse events were reported in the included studies. The certainty of evidence was very low. We found no studies comparing FNB to inhaled analgesics, opioids or ketamine. CONCLUSIONS: Evidence regarding the effectiveness and adverse effects of pre-hospital FNB is limited. Studies comparing pre-hospital FNB to inhaled analgesics, opioids or ketamine are lacking.

Time Course of Hoist Operations by the Search and Rescue Helicopter Service in Southeast Norway.

INTRODUCTION: Optimal dispatch of emergency medical services relies on accurate time estimates of the various prehospital stages. Hoist rescue work time intervals performed by the search and rescue (SAR) helicopter service in Norway have not been studied to date. We aimed to describe the epidemiologic, operational, and medical aspects of the SAR service in southeast Norway. To complement the prehospital timeline, we performed simulated hoist operations. METHODS: We reviewed time and patient descriptors and medical interventions in hoist operations performed at a SAR base over 5 y. In addition, a simulation study measuring hoist rescue time intervals was performed. Data are presented as mean±SD, except National Advisory Committee for Aeronautics (NACA) scores, which are presented as modes. RESULTS: There were 148 hoist operations performed during the study period, involving 180 patients. Time to take-off was 13±7 min. There were 88 patients (49%) who were injured; 53 (29%) had a medical condition, and 39 (22%) were evacuees. The mode of the NACA score was 3. Forty-five patients (25%) had an NACA score of 4 to 6. Medical interventions were performed on 77 patients (43%) in 73 operations (49%). Nine patients (5%) were endotracheally intubated, and 1 thoracostomy was performed. The simulated rescuer access time was 4±2 min, the simulated anesthesiologist access time was 6±2 min, and the simulated hoist extrication time was 13±2 min. CONCLUSIONS: Hoist rescue was performed in 10% (n=148) of the SAR operations. New information about hoist extrication time intervals can improve rescue helicopter dispatch accuracy.

Static Rope Evacuation by Helicopter Emergency Medical Services in Rescue Operations in Southeast Norway.

INTRODUCTION: Physician-staffed helicopter emergency medical services (HEMS) in Norway are an adjunct to existing search and rescue services. Our aims were to study the epidemiological, operational, and medical aspects of HEMS daylight static rope operations performed in the southeastern part of the country and to examine several quality dimensions that are characteristic of this service. METHODS: We reviewed the static rope operations performed at 3 HEMS bases during a 3-y period and applied a set of quality indicators designed for physician-staffed emergency medical services to evaluate the quality of care. Data are presented as medians with quartiles, except National Advisory Committee for Aeronautics (NACA) scores, which are presented as mean (SD). RESULTS: Fifty-nine static rope operations were identified, involving 60 patients. Median (quartiles) age was 43 (27-55) y. Median (quartiles) take-off time was 9 (5-13) min. Trauma-related injuries were found in 48 patients. The main conditions were lower limb injuries, found in 32 patients. Ten patients experienced medical conditions. Mean (SD) NACA score was 3.3 (1.3). A potential or actual life-threatening diagnosis (NACA score: 4-6) was reported among 15 patients. The main interventions were intravenous lines (19 patients), analgesics (17), and oxygen treatment (14). Four patients were intubated, and 1 thoracostomy was performed. CONCLUSIONS: Static rope operations are rarely performed. The quality indicators suggest that the service is safe, available, and equitable. Its main benefit seems to be evacuation and the maintenance of readiness before rapid transport of the physician to the scene or the patient to the hospital.

Hypoxia and hypotension in patients intubated by physician staffed helicopter emergency medical services - a prospective observational multi-centre study.

BACKGROUND: The effective treatment of airway compromise in trauma and non-trauma patients is important. Hypoxia and hypotension are predictors of negative patient outcomes and increased mortality, and may be important quality indicators of care provided by emergency medical services. Excluding cardiac arrests, critical trauma and non-trauma patients remain the two major groups to which helicopter emergency medical services (HEMS) are dispatched. Several studies describe the impact of pre-hospital hypoxia or hypotension on trauma patients, but few studies compare this in trauma and non-trauma patients. The primary aim was to describe the incidence of pre-hospital hypoxia and hypotension in the two groups receiving pre-hospital tracheal intubation (TI) by physician-staffed HEMS. METHODS: Data were collected prospectively over a 12-month period, using a uniform Utstein-style airway template. Twenty-one physician-staffed HEMS in Europe and Australia participated. We compared peripheral oxygen saturation and systolic blood pressure before and after definitive airway management. Data were analysed using Cochran-Mantel-Haenszel methods and mixed-effects models. RESULTS: Eight hundred forty three trauma patients and 422 non-trauma patients receiving pre-hospital TI were included. Non-trauma patients had significantly lower predicted mean pre-intervention SpO2 compared to trauma patients. Post-intervention and admission SpO2 for the two groups were comparable. However, 3% in both groups were still hypoxic at admission. For hypotension, the differences between the groups were less prominent. However, 9% of trauma and 10% of non-trauma patients were still hypotensive at admission. There was no difference in short-term survival between trauma (97%) and non-trauma patients (95%). Decreased level of consciousness was the most frequent indication for TI, and was associated with increased survival to hospital (cOR 2.8; 95% CI: 1.4-5.4). CONCLUSIONS: Our results showed that non-trauma patients had a higher incidence of hypoxia before TI than trauma patients, but few were hypoxic at admission. The difference for hypotension was less prominent, but one in ten patients were still hypotensive at admission. Further investigations are needed to identify reversible causes that may be corrected to improve haemodynamics in the pre-hospital setting. We found high survival rates to hospital in both groups, suggesting that physician-staffed HEMS provide high-quality emergency airway management in trauma and non-trauma patients. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT01502111 . Registered 22 Desember 2011.

Cross-sectional investigation of HEMS activities in Europe: a feasibility study.

OBJECTIVES: To gather information on helicopter emergency medical services (HEMSs) activities across Europe. METHODS: Cross-sectional data-collection on daily (15 November 2013) activities of a sample of European HEMSs. A web-based questionnaire with both open and closed questions was used, developed by experts of the European Prehospital Research Alliance (EUPHOREA). RESULTS: We invited 143 bases from 11 countries; 85 (60%) reported base characteristics only and 73 (51%) sample-day data too. The variety of base characteristics was enormous; that is, the target population ranged from 94.000 to 4.500.000. Of 158 requested primary missions, 62 (0.82 per base) resulted in landing. Cardiac aetiology (36%) and trauma (36%) prevailed, mostly of life-threatening severity (43%, 0.64 per mission). Had HEMS been not dispatched, patients would have been attended by another physician in 67% of cases, by paramedics in 24%, and by nurses in 9%. On-board physicians estimated to have caused a major decrease of death risk in 47% of missions, possible decrease in 22%, minor benefit in 17%, no benefit in 11%, and damage in 3%. Earlier treatment and faster transport to hospital were the main reasons for benefit. The most frequent therapeutic procedure was drug administration (78% of missions); endotracheal intubation occurred in 25% of missions and was an option hardly offered by ground crews. CONCLUSIONS: The study proved feasible, establishing an embryonic network of European HEMS. The participation rate was low and limits the generalizability of the results. Fortunately, because of its cross-sectional characteristics and the handy availability of the web platform, the study is easily repeatable with an enhanced network.

Opioids for Treatment of Pre-hospital Acute Pain: A Systematic Review.

INTRODUCTION: Acute pain is a frequent symptom among patients in the pre-hospital setting, and opioids are the most widely used class of drugs for the relief of pain in these patients. However, the evidence base for opioid use in this setting appears to be weak. The aim of this systematic review was to explore the efficacy and safety of opioid analgesics in the pre-hospital setting and to assess potential alternative therapies. METHODS: The PubMed, EMBASE, Cochrane Library, Centre for Reviews and Dissemination, Scopus, and Epistemonikos databases were searched for studies investigating adult patients with acute pain prior to their arrival at hospital. Outcomes on efficacy and safety were assessed. Risk of bias for each included study was assessed according to the Cochrane approach, and confidence in the evidence was assessed using the GRADE method. RESULTS: A total of 3453 papers were screened, of which the full text of 125 was assessed. Twelve studies were ultimately included in this systematic review. Meta-analysis was not undertaken due to substantial clinical heterogeneity among the included studies. Several studies had high risk of bias resulting in low or very low quality of evidence for most of the outcomes. No pre-hospital studies compared opioids with placebo, and no studies assessed the risk of opioid administration for subgroups of frail patients. The competency level of the attending healthcare provider did not seem to affect the efficacy or safety of opioids in two observational studies of very low quality. Intranasal opioids had a similar effect and safety profile as intravenous opioids. Moderate quality evidence supported a similar efficacy and safety of synthetic opioid compared to morphine. CONCLUSIONS: Available evidence for pre-hospital opioid administration to relieve acute pain is scarce and the overall quality of evidence is low. Intravenous administration of synthetic, fast-acting opioids may be as effective and safe as intravenous administration of morphine. More controlled studies are needed on alternative routes for opioid administration and pre-hospital pain management for potentially more frail patient subgroups.

Incidence of desaturation during prehospital rapid sequence intubation in a physician-based helicopter emergency service.

BACKGROUND: Hypoxemia may occur during rapid sequence intubation (RSI). This study establishes the incidence of this adverse event in patients intubated by physicians in a helicopter emergency service in Norway. METHODS: This was a prospective, observational study of all RSIs performed by helicopter emergency service physicians during a 12-month period. Hypoxemia was defined as a decrease in Spo(2) values to below 90% or a decrease of more than 10% if the initial Spo(2) was less than 90%. RESULTS: A total of 122 prehospital intubations were performed during the study period. Spo(2) data were available for 101 (82.8%) patients. Hypoxemia was present in 11 (10.9%) patients. CONCLUSIONS: Prehospital, RSI-related hypoxemia rates in this study are lower than reported rates in similar studies and are comparable with in-hospital rates. Prehospital RSI may accordingly be considered a safe procedure when performed by experienced physicians with appropriate field training.

Landing sites and intubation may influence helicopter emergency medical services on-scene time.

BACKGROUND: Reduced transport time of patients from the scene of an accident to definitive surgical treatment is one important reason to employ ambulance helicopters on trauma missions. However, if the helicopter is unable to land close to the scene, the transport time may be increased compared to transport with ground ambulance, due to time-consuming transfer of the patient between vehicles. OBJECTIVE: The objective of this study was to evaluate how the landing site, as determined by distance from the scene, and rapid sequence intubation (RSI) affected on-scene time (OST). METHODS: This was a prospective observational study performed during a 12-month period in a mixed urban and rural anesthesiologist-staffed Helicopter Emergency Medical Service in Norway. Data regarding the landing sites, the accident, and patient treatment were recorded. RESULTS: A total of 252 primary trauma missions were included in the study. In 75% of the missions, the aircraft landed<50 meters from the scene, and in 7% the distance exceeded 200 meters. Mean OST when the patient was not intubated was 14.5 min (median 14 min). When an RSI was performed, the mean OST was significantly higher (22.7 min, median 20 min; p<0.001). CONCLUSION: Usually, a helicopter can land close to the accident scene and the location of the landing site does not contribute to a delay in arrival of the patient at the hospital. The OST is significantly higher, however, in those patients who receive endotracheal intubation before take-off. This reflects the time needed for intubation, as well as the increased complexity and workload when the patient is severely injured.

Dispatch accuracy of physician-staffed emergency medical services in trauma care in south-east Norway: a retrospective observational study.

BACKGROUND: Selection of incidents and accurate identification of patients that require assistance from physician-staffed emergency medical services (P-EMS) remain essential. We aimed to evaluate P-EMS availability, the underlying criteria for dispatch, and the corresponding dispatch accuracy of trauma care in south-east Norway in 2015, to identify areas for improvement. METHODS: Pre-hospital data from emergency medical coordination centres and P-EMS medical databases were linked with data from the Norwegian Trauma Registry (NTR). Based on a set of conditions (injury severity, interventions performed, level of consciousness, incident category), trauma incidents were defined as complex, warranting P-EMS assistance, or non-complex. Incident complexity and P-EMS involvement were the main determinants when assessing the triage accuracy. Undertriage was adjusted for P-EMS availability and response and transport times. RESULTS: Among 19,028 trauma incidents, P-EMS were involved in 2506 (13.2%). The range of overtriage was 74-80% and the range of undertriage was 20-32%. P-EMS readiness in the event of complex incidents ranged from 58 to 70%. The most frequent dispatch criterion was "Police/fire brigade request immediate response" recorded in 4321 (22.7%) of the incidents. Criteria from the groups "Accidents" and "Road traffic accidents" were recorded in 10,875 (57.2%) incidents, and criteria from the groups "Transport reservations" and "Unidentified problem" in 6025 (31,7%) incidents. Among 4916 patient pathways in the NTR, 681 (13.9%) could not be matched with pre-hospital data records. CONCLUSIONS: Both P-EMS availability and dispatch accuracy remain suboptimal in trauma care in south-east Norway. Dispatch criteria are too vague to facilitate accurate P-EMS dispatch, and pre-hospital data is inconsistent and insufficient to provide basic data for scientific research. Future dispatch criteria should focus on the care aspect of P-EMS. Better tools for both dispatch and incident handling for the emergency medical coordination centres are essential. In general, coordination, standardisation, and integration of existing data systems should enhance the quality of trauma care and increase patient safety.

Ketamine for the treatment of prehospital acute pain: a systematic review of benefit and harm.

BACKGROUND: Few publications have addressed prehospital use of ketamine in analgesic doses. We aimed to assess the effect and safety profile of ketamine compared with other analgesic drugs (or no drug) in adult prehospital patients with acute pain. METHODS: A systematic review of clinical trials assessing prehospital administration of ketamine in analgesic doses compared with other analgesic drugs or no analgesic treatment in adults. We searched PubMed, EMBASE, Cochrane Library and Epistemonikos from inception until 15 February 2020, including relevant articles in English and Nordic languages. We used the Cochrane and Grading of Recommendations Assessment, Development and Evaluation methodologies and exclusively assessed patient-centred outcomes. Two independent authors screened trials for eligibility, extracted data and assessed risk of bias. RESULTS: We included eight studies (2760 patients). Ketamine was compared with various opioids given alone, and intranasal ketamine given with nitrous oxide was compared with nitrous oxide given alone. Four randomised controlled trials (RCTs) and one cluster randomised trial included 699 patients. One prospective cohort included 27 patients and two retrospective cohorts included 2034 patients. Five of the eight studies had high risks of bias. Pain score with ketamine is probably lower than after opioids as demonstrated in a cluster-RCT (308 patients) and a retrospective cohort (158 patients) study, Δvisual analogue scale -0.4 (-0.8 to 0.0) and Δnumeric pain rating scale -3.0 (-3.86 to -2.14), respectively. Ketamine probably leads to less nausea and vomiting (risk ratio (RR) 0.24 (0.11 to 0.52)) but more agitation (RR 7.81 (1.85 to 33)) than opioids. CONCLUSIONS: This systematic literature review finds that ketamine probably reduces pain more than opioids and with less nausea and vomiting but higher risk of agitation. Risk of bias in included studies is high. OTHER: Scandinavian society of anaesthesiology and intensive care medicine funded meetings and software. The Norwegian Air Ambulance Foundation funded publication. Otherwise this research received no grant from any agency in the public, commercial or not-for-profit sectors. PROSPERO REGISTRATION NUMBER: CRD42018114399.

Determination of prognosis after cardiac arrest may be more difficult after introduction of therapeutic hypothermia.

A 50-year-old patient had status epilepticus and no adequate reactions nine days after prolonged out-of-hospital cardiac arrest. The cause of the arrest was acute myocardial infarction which was treated successfully with percutaneous cardiac intervention (PCI) and a stent placement. He was treated with therapeutic hypothermia (33 degrees C) for 24h and in intensive care with respiratory support for 42 days. One year later he has fully recovered and is back to normal life and academic work. The previously reported 100% prognosis of a poor neurological outcome in the presence of seizures 72 h post arrest may need to be re-examined after introduction of therapeutic hypothermia.

A prospective survey of critical care procedures performed by physicians in helicopter emergency medical service: is clinical exposure enough to stay proficient?

BACKGROUND: Physicians in prehospital care must be proficient in critical care procedures. Procedure proficiency requires a combination of training, experience and continuous clinical exposure. Most physicians in helicopter emergency medical service (HEMS) in Norway are well-trained and experienced anaesthesiologists, but we know little about their exposure to critical care procedures in the prehospital arena. This knowledge is required to plan clinical training and in-hospital practice to maintain core competences for a HEMS physician. METHODS: We collected survey data on critical care procedures performed by physicians at three HEMS bases in Norway for a one-year period. To correct for differences in duty time between physicians, the expected number of procedures performed in a full time engagement at each HEMS base was calculated. Data was analysed using descriptive statistics and expected procedure volume at each base was compared using one-way between group analysis of variance. RESULTS: We received data from 82.7 % of the duty hours in the study period. Physicians at Oslo University Hospital HEMS had the highest volume of procedures in most categories and were expected to perform a majority of the procedures at least once a year. There were significant differences in procedure volume between the bases in 25 procedures. CONCLUSIONS: Physicians in Norwegian HEMS perform critical care procedures with variable frequencies. The low procedure volume in some cases and variance between bases indicate the need for a tailored procedure maintenance training and relevant in-hospital clinical practice.

Is the supine position associated with loss of airway patency in unconscious trauma patients? A systematic review and meta-analysis.

BACKGROUND: Airway compromise is a leading cause of death in unconscious trauma patients. Although endotracheal intubation is regarded as the gold standard treatment, most prehospital providers are not trained to perform ETI in such patients. Therefore, various lateral positions are advocated for unconscious patients, but their use remains controversial in trauma patients. We conducted a systematic review to investigate whether the supine position is associated with loss of airway patency compared to the lateral position. METHODS: The review protocol was published in the PROSPERO database (Reg. no. CRD42012001190). We performed literature searches in PubMed, Medline, EMBASE, Cochrane Library, CINAHL and British Nursing Index and included studies related to airway patency, reduced level of consciousness and patient position. We conducted meta-analyses, where appropriate. We graded the quality of evidence with the GRADE methodology. The search was updated in June 2014. RESULTS: We identified 1,306 publications, 39 of which were included for further analysis. Sixteen of these publications were included in meta-analysis. We did not identify any studies reporting direct outcome measures (mortality or morbidity) related to airway compromise caused by the patient position (lateral vs. supine position) in trauma patients or in any other patient group. In studies reporting only indirect outcome measures, we found moderate evidence of reduced airway patency in the supine vs. the lateral position, which was measured by the apnea/hypopnea index (AHI). For other indirect outcomes, we only found low or very low quality evidence. CONCLUSIONS: Although concerns other than airway patency may influence how a trauma patient is positioned, our systematic review provides evidence supporting the long held recommendation that unconscious trauma patients should be placed in a lateral position.

Does turning trauma patients with an unstable spinal injury from the supine to a lateral position increase the risk of neurological deterioration?--A systematic review.

BACKGROUND: Airway protection and spinal precautions are competing concerns in the treatment of unconscious trauma patients. The placement of such patients in a lateral position may facilitate the acquisition of an adequate airway. However, trauma dogma dictates that patients should be transported in the supine position to minimize spinal movement. In this systematic review, we sought to answer the following question: Given an existing spinal injury, will changing a patient's position from supine to lateral increase the risk of neurological deterioration? METHODS: The review protocol was published in the PROSPERO database (Reg. no. CRD42012001190). We performed literature searches in PubMed, Medline, EMBASE, the Cochrane Library, CINAHL and the British Nursing Index and included studies of traumatic spinal injury, lateral positioning and neurological deterioration. The search was updated prior to submission. Two researchers independently completed each step in the review process. RESULTS: We identified 1,164 publications. However, none of these publications reported mortality or neurological deterioration with lateral positioning as an outcome measure. Twelve studies used movement of the injured spine with lateral positioning as an outcome measure; eleven of these investigations were cadaver studies. All of these cadaver studies reported spinal movement during lateral positioning. The only identified human study included eighteen patients with thoracic or lumbar spinal fractures; according to the study authors, the logrolling technique did not result in any neurological deterioration among these patients. CONCLUSIONS: We identified no clinical studies demonstrating that rotating trauma patients from the supine position to a lateral position affects mortality or causes neurological deterioration. However, in various cadaver models, this type of rotation did produce statistically significant displacements of the injured spine. The clinical significance of these cadaver-based observations remains unclear. The present evidence for harm in rotating trauma patients from the supine position to a lateral position, including the logroll maneuver, is inconclusive.

Airway management by physician-staffed Helicopter Emergency Medical Services - a prospective, multicentre, observational study of 2,327 patients.

BACKGROUND: Despite numerous studies on prehospital airway management, results are difficult to compare due to inconsistent or heterogeneous data. The objective of this study was to assess advanced airway management from international physician-staffed helicopter emergency medical services. METHODS: We collected airway data from 21 helicopter emergency medical services in Australia, England, Finland, Hungary, Norway and Switzerland over a 12-month period. A uniform Utstein-style airway template was used for collecting data. RESULTS: The participating services attended 14,703 patients on primary missions during the study period, and 2,327 (16 %) required advanced prehospital airway interventions. Of these, tracheal intubation was attempted in 92 % of the cases. The rest were managed with supraglottic airway devices (5 %), bag-valve-mask ventilation (2 %) or continuous positive airway pressure (0.2 %). Intubation failure rates were 14.5 % (first-attempt) and 1.2 % (overall). Cardiac arrest patients showed significantly higher first-attempt intubation failure rates (odds ratio: 2.0; 95 % CI: 1.5-2.6; p < 0.001) compared to non-cardiac arrest patients. Complications were recorded in 13 %, with recognised oesophageal intubation being the most frequent (25 % of all patients with complications). For non-cardiac arrest patients, important risk predictors for first-attempt failure were patient age (a non-linear association) and administration of sedatives (reduced failure risk). The patient's sex, provider's intubation experience, trauma type (patient category), indication for airway intervention and use of neuromuscular blocking agents were not risk factors for first-attempt intubation failure. CONCLUSIONS: Advanced airway management in physician-staffed prehospital services was performed frequently, with high intubation success rates and low complication rates overall. However, cardiac arrest patients showed significantly higher first-attempt failure rates compared to non-cardiac arrest patients. All failed intubations were handled successfully with a rescue device or surgical airway. STUDY REGISTRATION: www.clinicaltrials.gov NCT01502111 . Registered 22 December 2011.