Prehospital Ultrasound by Paramedics: Results of Field Trial

Objectives: The objective was to determine if 9‐1‐1 paramedics trained in ultrasound (US) could adequately perform and interpret the Focused Assessment Sonography in Trauma (FAST) and the abdominal aortic (AA) exams in the prehospital care environment. Methods: Paramedics at two emergency medical services (EMS) agencies received a 6‐hour training program in US with ongoing refresher education. Paramedics collected US in the field using a prospective convenience methodology. All US were performed in the ambulance without scene delay. US exams were reviewed in a blinded fashion by an emergency sonographer physician overreader (PO). Results: A total of 104 patients had an US performed between January 1, 2008, and January 1, 2009. Twenty AA exams were performed and all were interpreted as negative by the paramedics and the PO. Paramedics were unable to obtain adequate images in 7.7% (8/104) of the patients. Eighty‐four patients had the FAST exam performed. Six exams (6/84, 7.1%) were read as positive for free intraperitoneal/pericardial fluid by both the paramedics and the PO. FAST and AA US exam interpretation by the paramedics had a 100% proportion of agreement with the PO. Conclusions: This pilot study shows that with close supervision, paramedics can adequately obtain and interpret prehospital FAST and AA US images under protocol. These results support a growing body of literature that indicates US may be feasible and useful in the prehospital setting. ACADEMIC EMERGENCY MEDICINE 2010; 17:624–630 © 2010 by the Society for Academic Emergency Medicine     

A Comparison of Rapid-Sequence Intubation andEtomidate-Only Intubation in the Prehospital Air Medical Setting

Objectives. To compare laryngoscopy conditions produced by etomidate-only intubation (EOI) with those produced by rapid-sequence intubation (RSI) in the prehospital air medical setting. Methods. A prospective crossover trial design used two helicopters staffed by the same flight paramedics andnurses. Each aircraft used an EOI protocol (0.3 mg/kg) for six months. An RSI protocol using the same dose of etomidate plus succinylcholine (1.5 mg/kg) was used for the alternate six months. Laryngoscopy conditions were graded by three scales: 1) a formal Laryngoscopy Grading Scale (LGS), 2) the Percentage of Glottic Opening (POGO) score, and3) subjective overall intubation difficulty using a Likert scale of 1 (very easy) to 5 (very difficult). Orotracheal intubation success was also recorded. Results. Forty-nine patients were intubated using the EOI (n = 24) andRSI (n = 25) protocols. Mean age was 38 years, 76% were male, and90% were intubated for trauma. Fifteen (63%) of the 24 EOI patients required additional etomidate (n = 3) or RSI (n = 12) to allow intubation, while one (4%) of the 25 RSI patients required additional medication dosing (p < 0.0001). Laryngoscopy conditions were assessed for all patients. Good or acceptable conditions as assessed by the LGS were seen in 79% of RSI patients and13% of EOI patients (p < 0.0001). Mean rates of POGO visualization were 60% with RSI and12% with EOI (p < 0.0001). Mean global intubation difficulty scores were 3.0 (moderate) with RSI and4.7 (difficult to very difficult) with EOI (p < 0.0001). Ninety-two percent of the patients undergoing RSI and25% of the EOI patients were successfully orotracheally intubated (p < 0.0001). Conclusions. Patients receiving RSI had better laryngoscopy conditions andwere easier to intubate than patients receiving EOI. Intubation success rate was higher with RSI.     

Multivariate Predictors of Failed Prehospital Endotracheal Intubation

OBJECTIVES: Conventionally trained out-of-hospital rescuers (such as paramedics) often fail to accomplish endotracheal intubation (ETI) in patients requiring invasive airway management. Previous studies have identified univariate variables associated with failed out-of-hospital ETI but have not examined the interaction between the numerous factors impacting ETI success. This study sought to use multivariate logistic regression to identify a set of factors associated with failed adult out-of-hospital ETI. METHODS: The authors obtained clinical and demographic data from the Prehospital Airway Collaborative Evaluation, a prospective, multicentered observational study involving advanced life support (ALS) emergency medical services (EMS) systems in the Commonwealth of Pennsylvania. Providers used standard forms to report details of attempted ETI, including system and patient demographics, methods used, difficulties encountered, and initial outcomes. The authors excluded data from sedation-facilitated and neuromuscular blockade-assisted intubations. The main outcome measure was ETI failure, defined as failure to successfully place an endotracheal tube on the last out-of-hospital laryngoscopy attempt. Logistic regression was performed to develop a multivariate model identifying factors associated with failed ETI. RESULTS: Data were used from 45 ALS systems on 663 adult ETIs attempted during the period June 1, 2001, to November 30, 2001. There were 89 cases of failed ETI (failure rate 13.4%). Of 61 factors potentially related to ETI failure, multivariate logistic regression revealed the following significant covariates associated with ETI failure (odds ratio; 95% confidence interval; likelihood ratio p-value): presence of clenched jaw/trismus (9.718; 95% CI = 4.594 to 20.558; p < 0.0001); inability to pass the endotracheal tube through the vocal cords (7.653; 95% CI = 3.561 to 16.447; p < 0.0001); inability to visualize the vocal cords (7.638; 95% CI = 3.966 to 14.707; p < 0.0001); intact gag reflex (7.060; 95% CI = 3.552 to 14.033; p < 0.0001); intravenous access established prior to ETI attempt (3.180; 95% CI = 1.640 to 6.164; p = 0.0005); increased weight (ordinal scale) (1.555; 95% CI = 1.242 to 1.947; p = 0.0001); and electrocardiographic monitoring established prior to ETI attempt (0.199; 95% CI = 0.084 to 0.469; p = 0.0003). This model was the most parsimonious of the models evaluated and demonstrated good fit (Hosmer-Lemeshow test p = 0.471) and discrimination (area under ROC curve = 0.906). There were no significant interaction terms. CONCLUSIONS: The authors used multivariate logistic regression to identify a set of factors associated with failure to accomplish ETI in adult out-of-hospital patients. Findings from this analysis could provide the basis for clinical protocols or decision rules aimed at minimizing the incidence of out-of-hospital ETI failure.     

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.     

The Time Cost of Prehospital Intubation andIntravenous Access in Trauma Patients

Objectives. The prehospital management of trauma patients remains controversial. Little is known about the time each procedure contributes to the on-scene duration, andthis information would be helpful in prioritizing which procedures to perform in the prehospital setting. We sought to estimate the contribution of procedures to on-scene duration focusing on intubation andestablishment of intravenous (IV) access. Methods. Data were provided by the Office of Emergency Planning andResponse at the Mississippi Department of Health. Real-time prehospital patient-level data are collected by emergency medical services (EMS) providers for all 9-1-1 calls statewide. Linear regression was performed to determine the overall additional time for an average procedure andto calculate marginal increases in on-scene time associated with the establishment of IV access andwith endotracheal intubation. Analyses were performed using Stata 9. Results. During 2001–2005, 192,055 prehospital runs were made for trauma patients. 121,495 (63%) included prehospital procedures. Average on-scene duration for those runs was 15:24 (minutes:seconds). On average, each procedure was associated with an addition of 1 minute to the on-scene duration (95% confidence interval [CI]: 58–62 seconds). A scene involving the establishment of IV access was 5:04 longer, while one involving tracheal intubation was 2:36 longer. Conclusions. We estimate the marginal increase in on-scene duration associated with the performance of an average procedure, establishment of IV access, andendotracheal intubation. There are policy andplanning implications for the time trade-off of prehospital procedures, especially discretionary ones.     

Evaluation of Physiologic Alterations during Prehospital Paramedic-Performed Rapid Sequence Intubation

Objective: Physiologic alterations during rapid sequence intubation (RSI) have been studied in several emergency airway management settings, but few data exist to describe physiologic alterations during prehospital RSI performed by ground-based paramedics. To address this evidence gap and provide guidance for future quality improvement initiatives in our EMS system, we collected electronic monitoring data to evaluate peri-intubation vital signs changes occurring during prehospital RSI. Methods: Electronic patient monitor data files from cases in which paramedic RSI was attempted were prospectively collected over a 15-month study period to supplement the standard EMS patient care documentation. Cases were analyzed to identify peri-intubation changes in oxygen saturation, heart rate, and blood pressure. Results: Data from 134 RSI cases were available for analysis. Paramedic-assigned prehospital diagnostic impression categories included neurologic (42%), respiratory (26%), toxicologic (22%), trauma (9%), and cardiac (1%). The overall intubation success rate (95%) and first-attempt success rate (82%) did not differ across diagnostic impression categories. Peri-intubation desaturation (SpO₂ decrease to below 90%) occurred in 43% of cases, and 70% of desaturation episodes occurred on first-attempt success. The incidence of desaturation varied among patient categories, with a respiratory diagnostic impression associated with more frequent, more severe, and more prolonged desaturations, as well as a higher incidence of accompanying cardiovascular instability. Bradycardia (HR decrease to below 60 bpm) occurred in 13% of cases, and 60% of bradycardia episodes occurred on first-attempt success. Hypotension (systolic blood pressure decrease to below 90 mmHg) occurred in 7% of cases, and 63% of hypotension episodes occurred on first-attempt success. Peri-intubation cardiac arrest occurred in 2 cases, one of which was on first-attempt success. Only 11% of desaturations and no instances of bradycardia were reflected in the standard EMS patient care documentation. Conclusions: In this study, the majority of peri-intubation physiologic alterations occurred on first-attempt success, highlighting that first-attempt success is an incomplete and potentially deceptive measure of intubation quality. Supplementing the standard patient care documentation with electronic monitoring data can identify unrecognized physiologic instability during prehospital RSI and provide valuable guidance for quality improvement interventions.     

Prevalence of Difficult Airway Predictors in Cases of Failed Prehospital Endotracheal Intubation

Background

Difficult airway predictors (DAPs) are associated with failed endotracheal intubation (ETI) in the emergency department (ED). However, little is known about the relationship between DAPs and failed prehospital ETI.

Objective

Our aim was to determine the prevalence of common DAPs among failed prehospital intubations.

Methods

We reviewed a quality-improvement database, including all cases of ETI in a single ED, over 3 years. Failed prehospital (FP) ETI was defined as a case brought to the ED after attempted prehospital ETI, but bag-valve-mask ventilation, need for a rescue airway (supraglottic device, cricothyrotomy, etc.), or esophageal intubation was discovered at the ED. Physicians performing ETI evaluated each case for the presence of DAPs, including blood/emesis, facial/neck trauma, airway edema, spinal immobilization, short neck, and tongue enlargement.

Results

There were a total of 1377 ED ETIs and 161 had an FP-ETI (11.8%). Prevalence of DAPs in cases with FP-ETI was obesity 13.0%, large tongue 18.0%, short neck 13%, small mandible 4.3%, cervical immobility 49.7%, blood in airway 57.8%, vomitus in airway 23.0%, airway edema 12.4%, and facial or neck trauma 32.9%. The number of cases with FP-ETI and 0, 1, 2, 3, or 4 or more DAPs per case was 22 (13.6%), 43 (26.7%), 23 (24.3%), 42 (26.1%), and 31 (19.3%), respectively.

Conclusions

DAPs are common in cases of FP-ETI. Some of these factors may be associated with FP-ETI. Additional study is needed to determine if DAPs can be used to identify patients that are difficult to intubate in the field.     

Prehospital Intubation is Associated with Favorable Outcomes and Lower Mortality in ProTECT III

Objective: Traumatic brain injury (TBI) causes more than 2.5 million emergency department visits, hospitalizations, or deaths annually. Prehospital endotracheal intubation has been associated with poor outcomes in patients with TBI in several retrospective observational studies. We evaluated the relationship between prehospital intubation, functional outcomes, and mortality using high quality data on clinical practice collected prospectively during a randomized multicenter clinical trial. Methods: ProTECT III was a multicenter randomized, double-blind, placebo-controlled trial of early administration of progesterone in 882 patients with acute moderate to severe nonpenetrating TBI. Patients were excluded if they had an index GCS of 3 and nonreactive pupils, those with withdrawal of life support on arrival, and if they had documented prolonged hypotension and/or hypoxia. Prehospital intubation was performed as per local clinical protocol in each participating EMS system. Models for favorable outcome and mortality included prehospital intubation, method of transport, index GCS, age, race, and ethnicity as independent variables. Significance was set at α = 0.05. Favorable outcome was defined by a stratified dichotomy of the GOS-E scores in which the definition of favorable outcome depended on the severity of the initial injury. Results: Favorable outcome was more frequent in the 349 subjects with prehospital intubation (57.3%) than in the other 533 patients (46.0%, p = 0.003). Mortality was also lower in the prehospital intubation group (13.8% v. 19.5%, p = 0.03). Logistic regression analysis of prehospital intubation and mortality, adjusted for index GCS, showed that odds of dying for those with prehospital intubation were 47% lower than for those that were not intubated (OR = 0.53, 95% CI = 0.36–0.78). 279 patients with prehospital intubation were transported by air. Modeling transport method and mortality, adjusted for index GCS, showed increased odds of dying in those transported by ground compared to those transported by air (OR = 2.10, 95% CI = 1.40–3.15). Decreased odds of dying trended among those with prehospital intubation adjusted for transport method, index GCS score at randomization, age, and race/ethnicity (OR = 0.70, 95% CI = 0.37–1.31). Conclusions: In this study that excluded moribund patients, prehospital intubation was performed primarily in patients transported by air. Prehospital intubation and air medical transport together were associated with favorable outcomes and lower mortality. Prehospital intubation was not associated with increased morbidity or mortality regardless of transport method or severity of injury.     

Drug-Assisted Intubation in the Prehospital Setting (Resource Document to NAEMSP Position Statement)

We report an emergency medical services (EMS) case of self-limited torsade de pointes after administration of droperidol for nausea andvomiting in a patient with potential predisposing factors for the development of prolonged QT interval. Despite the reported association with torsade de pointes, many clinicians still consider droperidol to be a safe medication. Rare cardiac side effects may be avoided by reviewing risk factors for prolonged QT interval in individual patients prior to administering droperidol     

A Meta-Analysis of Prehospital Airway Control Techniques Part I: Orotracheal and Nasotracheal Intubation Success Rates

Abstract

Background. Airway management is a key component of prehospital care for seriously ill and injured patients. Although endotracheal intubation has been a commonly performed prehospital procedure for nearly three decades, the safety and efficacy profile of prehospital intubation has been challenged in the last decade. Reported intubation success rates vary widely, and established benchmarks are lacking. Objective. We sought to determine pooled estimates for oral endotracheal intubation (OETI) and nasotracheal intubation (NTI) placement success rates through a meta-analysis of the literature. Methods. We performed a systematic literature search for all English-language articles reporting placement success rates for prehospital intubation. Studies of field procedures performed by prehospital personnel from any nation were included. All titles were reviewed independently by two authors using prespecified inclusion criteria. Pooled estimates of success rates for each airway technique, including drug-facilitated intubation (DFI) and rapid-sequence intubation (RSI), were calculated using a random-effects model. Historical trends were evaluated using meta-regression. Results. Of 2,005 identified titles reviewed, 117 studies addressed OETI and 23 addressed NTI, encompassing a total of 57,132 prehospital patients. There was substantial interrater reliability in the review process (kappa = 0.81). The pooled estimates (and 95% confidence intervals [CIs]) for intervention success for nonphysician clinicians were as follows: overall non-RSI/non-DFI OETI success rate: 86.3% (82.6%–89.4%); OETI for non–cardiac arrest patients: 69.8% (50.9%–83.8%); DFI 86.8% (80.2%–91.4%); and RSI 96.7% (94.7%–98.0%). For pediatric patients, the paramedic OETI success rate was 83.2% (55.2%–95.2%). The overall NTI success rate for nonphysician clinicians was 75.9% (65.9%–83.7%). The historical trend of OETI reflects a 0.49% decline in success rates per year. Conclusions. We provide pooled estimates of placement success rates for prehospital airway interventions. For some patient and clinician characteristics, OETI has relatively low success rates. For nonarrest patients, DFI and RSI appear to increase success rates. Across all clinicians, NTI has a low rate of success, raising questions about the safety and efficacy of this procedure.     

A Continuous Quality Improvement Airway Program Results in Sustained Increases in Intubation Success

Introduction: Airway management is a critical skill for air medical providers, including the use of rapid sequence intubation (RSI) medications. Mediocre success rates and a high incidence of complications has challenged air medical providers to improve training and performance improvement efforts to improve clinical performance.

Objectives: The aim of this research was to describe the experience with a novel, integrated advanced airway management program across a large air medical company and explore the impact of the program on improvement in RSI success.

Methods: The Helicopter Advanced Resuscitation Training (HeART) program was implemented across 160 bases in 2015. The HeART program includes a novel conceptual framework based on thorough understanding of physiology, critical thinking using a novel algorithm, difficult airway predictive tools, training in the optimal use of specific airway techniques and devices, and integrated performance improvement efforts to address opportunities for improvement. The C-MAC video/direct laryngoscope and high-fidelity human patient simulation laboratories were implemented during the study period. Chi-square test for trend was used to evaluate for improvements in airway management and RSI success (overall intubation success, first-attempt success, first-attempt success without desaturation) over the 25-month study period following HeART implementation.

Results: A total of 5,132 patients underwent RSI during the study period. Improvements in first-attempt intubation success (85% to 95%, p < 0.01) and first-attempt success without desaturation (84% to 94%, p < 0.01) were observed. Overall intubation success increased from 95% to 99% over the study period, but the trend was not statistically significant (p = 0.311).

Conclusions: An integrated advanced airway management program was successful in improving RSI intubation performance in a large air medical company.