Unanticipated difficult airway management in the prehospital emergency setting: prospective validation of an algorithm.

BACKGROUND: Difficult intubation management algorithms have proven efficacy in operating rooms but have rarely been assessed in a prehospital emergency setting. We undertook a prospective evaluation of a simple prehospital difficult intubation algorithm. METHODS: All of our prehospital emergency physicians and nurse anesthetists were asked to adhere to a simple algorithm in all cases of impossible laryngoscope-assisted tracheal intubation. They received a short refresher course and training in the use of the gum elastic bougie (GEB) and the intubating laryngeal mask airway (ILMA), which were techniques to be used as a first and a second step, respectively. In cases of difficult ventilation with arterial desaturation, IMLA was to be used first. Cricothyroidotomy was the ultimate rescue technique when ventilation through ILMA failed. Patient characteristics, adherence to the algorithm, management efficacy, and early complications were recorded (August 2005-December 2009). RESULTS: An alternative technique to secure the airway was needed in 160 of 2,674 (6%) patients undergoing intubation. Three instances of nonadherence to the algorithm were recorded. GEB was used first in 152 patients and was successful in 115. ILMA was used first in 8 patients and second in the 37 GEB-assisted intubation failures. Forty-five patients were successfully mask-ventilated, and 42 were blindly intubated before reaching the hospital. Cricothyroidotomy was used successfully in a patient with severe upper airway obstruction as a result of pharyngeal neoplasia. Early intubation-related complications occurred in 52% difficult cases. CONCLUSION: Adherence to a simple algorithm using GEB, ILMA, and cricothyroidotomy solved all difficult intubation cases occurring in a prehospital emergency setting.

Out-of-hospital tracheal intubation with single-use versus reusable metal laryngoscope blades: a multicenter randomized controlled trial.

STUDY OBJECTIVE: Emergency tracheal intubation is reported to be more difficult with single-use plastic than with reusable metal laryngoscope blades in both inhospital and out-of-hospital settings. Single-use metal blades have been developed but have not been compared with conventional metal blades. This controlled trial compares the efficacy and safety of single-use metal blades with reusable metal blades in out-of-hospital emergency tracheal intubation. METHODS: This randomized controlled trial was carried out in France with out-of-hospital emergency medical units (Services de Médecine d'Urgence et de Réanimation). This was a multicenter prospective noninferiority randomized controlled trial in adult out-of-hospital patients requiring emergency tracheal intubation. Patients were randomly assigned to either single-use or reusable metal laryngoscope blades and intubated by a senior physician or a nurse anesthetist. The primary outcome was first-pass intubation success. Secondary outcomes were incidence of difficult intubation, need for alternate airway devices, and early intubation-related complications (esophageal intubation, mainstem intubation, vomiting, pulmonary aspiration, dental trauma, bronchospasm or laryngospasm, ventricular tachycardia, arterial desaturation, hypotension, or cardiac arrest). RESULTS: The study included 817 patients, including 409 intubated with single-use blades and 408 with a reusable blade. First-pass intubation success was similar in both groups: 292 (71.4%) for single-use blades, 290 (71.1%) for reusable blades. The 95% confidence interval (CI) for the difference in treatments (0.3%; 95% CI -5.9% to 6.5%) did not include the prespecified inferiority margin of -7%. There was no difference in rate of difficult intubation (difference 3%; 95% CI -7% to 2%), need for alternate airway (difference 4%; 95% CI -8% to 1%), or early complication rate (difference 3%; 95% CI -3% to 8%). CONCLUSION: First-pass out-of-hospital tracheal intubation success with single-use metal laryngoscopy blades was noninferior to first-pass success with reusable metal laryngoscope blades.

Bispectral index monitoring is useless during cardiac arrest patients' resuscitation.

AIM: It has been suggested that out-of-hospital bispectral (BIS) index monitoring during advanced cardiac life support (ACLS) might provide an indication of cerebral resuscitation. The aims of our study were to establish whether BIS values during ACLS might predict return to spontaneous circulation, and whether BIS values on hospital admission might predict survival. MATERIALS AND METHODS: This was a prospective observational study in 92 patients with cardiac arrest who received basic life support from a fire-fighter squad and ACLS on arrival of an emergency medical team on the scene. BIS values, electromyographic activity, and signal quality index were recorded throughout resuscitation and out-of-hospital management. RESULTS: Seven patients had recovered spontaneous cardiac activity by the time the medical team arrived on scene. Of the 92 patients, 62 patients died on scene and 30 patients returned to spontaneous cardiac activity and were admitted to hospital. The correlation between BIS values and end-tidal CO(2) during the first minutes of ACLS was poor (r(2)=0.02, P=0.19). Of the 30 admitted patients, 27 died. Three were discharged with no disabilities. There was no significant difference in BIS values on admission between the group of patients who died and the group who survived (P=0.78). CONCLUSIONS: Although BIS monitoring during resuscitation was not difficult, it did not predict return to spontaneous cardiac activity, nor survival after admission to intensive care. Its use to monitor cerebral function during ACLS is therefore pointless.

Capnography monitoring in nonintubated patients with respiratory distress.

OBJECTIVE: The objective was to assess agreement between end-tidal carbon dioxide values measured by a handheld capnometer (Petco(2)) and values measured by a blood gas analyzer (Paco(2)) in nonintubated patients with respiratory distress in an out-of-hospital setting. METHODS: This prospective study compared Petco(2) values obtained by an end-tidal capnometer (Microcap Plus; Oridion Capnography Inc, Needham, Mass) to Paco(2) values by the Bland and Altman statistical method. RESULTS: A total of 50 patients were included. Continuous Petco(2) monitoring was easily performed in all 50 patients during ambulance transport, but blood gas analysis failed in 1 patient. Agreement between the 2 methods was poor with a bias (mean difference) between Petco(2) and Paco(2) measurements of 12 mm Hg and a precision (SD of the difference) of 8 mm Hg. The gradient between Petco(2) and Paco(2) was greater than 5 and 10 mm Hg in 41 and 25 patients, respectively. CONCLUSIONS: Petco(2) measurements poorly reflected Paco(2) values in our population of nonintubated patients with respiratory distress of various origins.

Six-month outcome of emergency percutaneous coronary intervention in resuscitated patients after cardiac arrest complicating ST-elevation myocardial infarction.

BACKGROUND: The outcome of resuscitated patients after cardiac arrest complicating acute myocardial infarction remains poor, primarily because of the relatively low success rates of cardiopulmonary resuscitation management. Existing data suggest potential beneficial effects of early myocardial reperfusion, but the predictors of survival in these patients remain unknown. METHODS AND RESULTS: From 1995 to 2005, 186 patients (78% men; mean age, 60.4+/-13.8 years) underwent immediate percutaneous coronary intervention after successful resuscitation for cardiac arrest complicating acute myocardial infarction. Prompt prehospital management was performed by mobile medical care units in 154 of 186 patients, whereas 32 had in-hospital cardiac arrest. Infarct location was anterior in 105 patients (56%), and shock was present on admission in 96 (52%). Percutaneous coronary intervention (stenting rate 90%) was successful in 161 of 186 patients (87%). Six-month survival rate was 100 of 186 (54%), and 6-month survival free of neurological sequelae was 46%. By multivariate analysis, predictors of 6-month survival were a shorter interval between the onset of cardiac arrest and arrival of a first responder (odds ratio, 0.67; 95% CI, 0.54 to 0.84), a shorter interval between the onset of cardiac arrest and return of spontaneous circulation (odds ratio, 0.91; 95% CI, 0.87 to 0.96), and absence of diabetes (odds ratio, 7.30; 95% CI, 1.80 to 29.41). CONCLUSIONS: In patients with resuscitated cardiac arrest complicating acute myocardial infarction, prompt prehospital management and early revascularization were associated with a 54% survival rate at 6 months. A strategy including adequate prehospital management, early revascularization, and specific care in dedicated intensive care units should be strongly considered in resuscitated patients after cardiac arrest complicating acute myocardial infarction.

An observational study of noninvasive positive pressure ventilation in an out-of-hospital setting.

OBJECTIVE: Out-of-hospital clinical experience with noninvasive bilevel positive airway pressure (BiPAP) ventilation is extremely limited compared to inhospital management. The aims of this study were to assess the feasibility of out-of-hospital BiPAP ventilation in patients with acute respiratory distress of various origins, and to look for specific factors associated with failure of this respiratory support. METHODS: This 2-year prospective observational study assessed the failure rate of out-of-hospital BiPAP ventilation, the difficulties encountered, and factors predictive of failure by multivariate analysis. RESULTS: Overall, 138 patients were treated by out-of-hospital BiPAP for congestive heart failure (56%), chronic obstructive pulmonary disease exacerbation (28%), and acute respiratory failure (16%). Failure rate was 26% (35/138; 95% confidence interval, 18%-33%) (11 before and 24 after reaching hospital). Independent risk factors were the cause of respiratory distress (chronic obstructive pulmonary disease exacerbation; acute respiratory failure) and an audible air leakage. CONCLUSIONS: The failure rate of BiPAP initiated out-of-hospital was no different from previous reports for inhospital failure rates. Failure was attributable to similar causes.

A comparison of plastic single-use with metallic reusable laryngoscope blades for out-of-hospital tracheal intubation.

STUDY OBJECTIVE: The objective of this study was to compare, in the emergency out-of-hospital environment, intubation success rates during the first laryngoscopy for 2 laryngoscope blade types: a metallic reusable and a plastic single-use. METHODS: An observational before-and-after study was conducted during 2 1-year periods. Adult patients were intubated by emergency physicians, anesthesiologists, or anesthesia nurses in the out-of-hospital setting with metallic reusable (first period) or a plastic disposable (second period) Macintosh 3 or 4 laryngoscope blades. Immediately after intubation, data were collected on success rate of intubation at the first attempt, intubation difficulty score, quality of laryngeal visualization, and the need for alternative airway techniques. To compare the 2 periods of the study, Wilcoxon's test was used for quantitative variables, and the chi2 or Fisher's exact test was used for qualitative variables. RESULTS: Patients intubated with a metallic blade (594/1,177; 50.5%) and with a plastic blade (583/1,177; 49.5%) were included in the study. The first-attempt intubation success rate was higher in the metallic blade group (497/594, 84%) than in the single-use group (76%); difference 7% (95% confidence interval [CI] 3% to 12%) (P<.002). The incidence of difficult intubation, defined by an intubation difficulty score greater than 5, was lower (6% [95% CI 4% to 8%] versus 15% [95% CI 12% to 18%]) when metallic blades were used. A good laryngeal view (Cormack and Lehane classes I and II) was more frequently observed with metallic blade use (83% [95% CI 80% to 86%] versus 67% [95% CI 64% to 70%]). Alternative airway techniques such as the use of a Gum elastic bougie or an intubating laryngeal mask airway were more frequently used in the plastic blade period (12% [95% CI 10% to 14%] versus 4% [95% CI 2% to 6%]). CONCLUSION: In out-of-hospital emergency care, the use of a plastic disposable laryngoscope blade decreased the success rate of tracheal intubation at the first attempt performed by emergency care providers.

Overnight duty impairs behaviour, awake activity and sleep in medical doctors.

BACKGROUND: The impact of prolonged work cycles among senior doctors remains disputed. We evaluated the effects of overnight duty on awake activity and sleep quality in senior doctors in emergency medical specialties. METHODS: Thirty-six healthy doctors were monitored during a 2-week period including three separate 84 h on-call cycles. An on-call cycle consisted of the night and the day before night duty; the night duty itself and the subsequent 2 days and nights after night duty. The first day after night duty could either be worked or not. Actigraphy was used to measure physical activity and to evaluate sleep duration and quality. A standardized questionnaire was used to assess daytime performance and night sleep quality. RESULTS: Night actigraphy demonstrated that on-call work induced a significant reduction in sleep duration that was not recovered during the subsequent two nights. Sleep during the night duty itself was fragmented and of poor quality. Awake activity was significantly impaired on the day after night duty. Although subjectively night sleep quality did not differ between the nights before and after night duty, all subjective daytime parameters were impaired the day after night duty, and mood, fatigue and concentration remained altered on the second day. Working the day after night duty impaired objective measurements of daytime activity and sleep quality during the subsequent two nights. CONCLUSIONS: On-call night work in acute specialties induces sleep debt associated with prolonged impairment of awake activity, sleep quality and performance. Not working the following day after an on-call night allows partial recovery of sleep quality to begin.

Predictive factors for positive coronary angiography in out-of-hospital cardiac arrest patients.

OBJECTIVES: Coronary angiography is often performed in survivors of out-of-hospital cardiac arrest, but little is known about the factors predictive of a positive coronary angiography. Our aim was to determine these factors. METHODS: In this 7-year retrospective study (January 2000-December 2006) conducted by a French out-of-hospital emergency medical unit, data were collected according to Utstein style guidelines on all out-of-hospital cardiac arrest patients with suspected coronary disease who recovered spontaneous cardiac activity and underwent early coronary angiography. Coronary angiography was considered positive if a lesion resulting in more than a 50% reduction in luminal diameter was observed or if there was a thrombus at an occlusion site. RESULTS: Among the 4621 patients from whom data were collected, 445 were successfully resuscitated and admitted to hospital. Of these, 133 were taken directly to the coronary angiography unit, 95 (71%) had at least one significant lesion, 71 (53%) underwent a percutaneous coronary intervention, and 30 survived [23%, 95% confidence interval (CI): 16-30]. According to multivariate analysis, the factors predictive of a positive coronary angiography were a history of diabetes [odds ratio (OR): 7.1, 95% CI: 1.4-36], ST segment depression on the out-of-hospital ECG (OR: 5.4, 95% CI: 1.1-27.8), a history of coronary disease (OR: 5.3, 95% CI: 1.4-20.1), cardiac arrest in a public place (OR: 3.7, 95% CI: 1.3-10.7), and ventricular fibrillation or ventricular tachycardia as initial rhythm (OR: 3.1, 95% CI: 1.1-8.6). CONCLUSION: Among the factors identified, diabetes and a history of coronary artery were strong predictors for a positive coronary angiography, whereas ST segment elevation was not as predictive as expected.

Efficacy and safety of the EZ-IO™ intraosseous device: Out-of-hospital implementation of a management algorithm for difficult vascular access.

OBJECTIVE: Intraosseous access is a rapid and safe alternative when peripheral vascular access is difficult. Our aim was to assess the safety and efficacy of a semi-automatic intraosseous infusion device (EZ-IO) when using a management algorithm for difficult vascular access in an out-of-hospital setting. METHODS: This was a one-year prospective, observational study by mobile intensive care units. After staff training in the use of the EZ-IO device and provision of a management algorithm for difficult vascular access, all vehicles were equipped with the device. We determined device success rate and ease of use, resuscitation fluid volume and drugs administered by the intraosseous route, and complications at insertion site. RESULTS: A total of 4666 patients required vascular access. The EZ-IO device was used in 30 cardiac arrest patients (25 adults; 5 children) and 9 adults with spontaneous cardiac activity. The success rate for first insertion was 84%. Overall success rate (max. 2 attempts) was 97%. The device was used for fluid resuscitation in 16 patients (mean volume: 680ml), adrenaline administration in 24 patients, and rapid sequence induction in 2 patients. There was only one local complication (transient local inflammation). CONCLUSIONS: On implementation of an algorithm for the management of difficult vascular access, the EZ-IO device proved safe and highly effective in both adult and paediatric patients in an out-of-hospital emergency setting. It is a suitable device for consideration as a first-line option for difficult vascular access in this setting.

Randomized comparison of eptifibatide versus abciximab in primary percutaneous coronary intervention in patients with acute ST-segment elevation myocardial infarction: results of the EVA-AMI Trial.

OBJECTIVES: The aim of this study was to compare eptifibatide and abciximab as adjuncts to primary percutaneous coronary intervention (PCI). BACKGROUND: The glycoprotein (GP) IIb/IIIa receptor inhibitor abciximab as adjunct to primary PCI in patients with ST-segment elevation myocardial infarctions has been shown to reduce ischemic complications and improve clinical outcomes. So far, no trial has been performed to compare the efficacy of another GP IIb/IIIa receptor inhibitor, eptifibatide, and abciximab in primary PCI. METHODS: A total of 427 patients with ST-segment elevation myocardial infarctions <12 h and planned primary PCI were randomized to double-bolus eptifibatide (n = 226) followed by a 24-h infusion or single-bolus abciximab (n = 201) followed by a 12-h infusion. In this noninferiority trial, the primary end point was the incidence of complete (> or =70%) ST-segment resolution (STR) 60 min after PCI, a measure of myocardial reperfusion. The assumption was a 60% complete STR rate in the abciximab group. The noninferiority margin was set to 15%. RESULTS: The incidence of complete STR at 60 min after PCI in the intention-to-treat analysis was 62.6% after eptifibatide and 56.3% after abciximab (adjusted difference: 7.1%; 95% confidence interval: 2.7% to 17.0%). All-cause mortality 6.2% versus 4.5% (p = 0.50); reinfarction 0.4% versus 3.5% (p = 0.03); target vessel revascularization 4.4% versus 6.5% (p = 0.40); the combined end point of death, nonfatal reinfarction, and target vessel revascularization 10.6% versus 10.9% (p = 0.90); stroke 0.5% versus 0.5% (p = 1.00) after 6 months; and Thrombolysis In Myocardial Infarction major bleeding complications 4.0% versus 2.0% (p = 0.20) after 30 days were observed after eptifibatide and abciximab, respectively. CONCLUSIONS: Eptifibatide as an adjunct to primary PCI is equally as effective as abciximab with respect to STR. (Efficacy of Eptifibatide Compared to Abciximab in Primary Percutaneous Coronary Intervention [PCI] for Acute ST Elevation Myocardial Infarction [STEMI]; NCT00426751).

Prehospital standardization of medical airway management: incidence and risk factors of difficult airway.

OBJECTIVES: The rate of difficult intubation in prehospital emergency medicine varies greatly among studies already published and depends on several factors. The authors' objective was to determine the rate of difficult intubations and to determine factors associated with prehospital difficult airways when a standard protocol for sedation and intubation was applied. METHODS: This 30-month clinical, observational, prospective study was performed in a suburb of Paris, France (Val de Marne, population 1,300,000) by a prehospital emergency medical unit. Airway management for patients who needed tracheal intubation was standardized. The pharmacological procedure recommended rapid sequence intubation for patients with spontaneous cardiac activity. In cases of difficult, laryngoscopy-assisted intubation, a predefined algorithm was proposed. The Intubation Difficulty Score (IDS) was calculated for all patients requiring tracheal intubation, and factors associated with difficult intubation, defined by IDS of >5, were identified by using multivariate statistical analysis. RESULTS: During the study period, 1,442 patients were included; 640 (44%) were in cardiorespiratory arrest, and 802 had a spontaneous cardiac activity. Deviation from the pharmacological and airway management procedures occurred in 1% of cases. When the predefined difficult airway management algorithm was followed, failure to intubate was encountered twice (0.1%). One hundred six (7.4%) patients had an IDS of >5, and 60 (4.1%) required first (n = 56) then second (n = 4) alternative techniques for tracheal intubation. Semirigid leaders allowed tracheal access in 93% of difficult-intubation patients. One patient required a prehospital cricothyroidotomy. Factors associated with difficult intubation were the following: a history of ear, nose, or throat neoplasia or surgery; obesity; facial trauma; the operator's status; and the operator's position. CONCLUSIONS: If prehospital medical airway management is standardized and performed by trained operators, failure to intubate is rare (0.1%), and the incidence of difficult tracheal intubation is 7.4%, independent of cardiorespiratory status.

Use of gum elastic bougie for prehospital difficult intubation.

The objective of this study was to assess effectiveness of gum elastic bougie (GEB) in case of difficult intubation occurring in the prehospital settings. After manikin training to GEB handling, physicians were recommended to use GEB as first alternative technique in case of difficult intubation. Intubating conditions and details of patients requiring GEB-assisted laryngoscopy were recorded over 30 months. Among the 1442 extrahospital intubations performed, 41 patients (3%) required GEB. Gum elastic bougie allowed successful intubation in 33 cases (78%) and 8 patients sustained a second alternative technique. One patient was never intubated, another 1 required rescue cricothyroidotomy. Twenty-four (60%) GEB patients had associated factors for difficult intubation such as reduced or limited cervical spine mobility, morbid obesity, cervicofacial trauma, and ears, nose, and throat neoplasia. The success rate of GEB was 75% and 94%, respectively, depending on whether associated factors for difficult intubation are present or not. No adverse events associated to GEB use were noted.