In out-of-hospital cardiac arrest, is the positioning of victims by bystanders adequate for CPR? A cohort study.

OBJECTIVES: Outcome from out-of-hospital cardiac arrest (OHCA) highly depends on bystander cardiopulmonary resuscitation (CPR) with high-quality chest compressions (CCs). Precondition is a supine position of the victim on a firm surface. Until now, no study has systematically analysed whether bystanders of OHCA apply appropriate positions to victims and whether the position is associated with a particular outcome. DESIGN: Prospective observational cohort study. SETTING: Metropolitan emergency medical services (EMS) serving a population of 400 000; dispatcher-assisted CPR was implemented. We obtained information from the first EMS vehicle arriving on scene and matched this with data from semi-structured interviews with witnesses of the arrest. PARTICIPANTS: Bystanders of all OHCAs occurring during a 12-month period (July 2006-July 2007). From 201 eligible missions, 200 missions were fully reported by EMS. Data from 138 bystander interviews were included. PRIMARY AND SECONDARY OUTCOME MEASURES: Proportion of positions suitable for effective CCs; related survival with favourable neurological outcome at 3 months. RESULTS: Positioning of victims at EMS arrival was 'supine on firm surface' in 64 cases (32.0%), 'recovery position (RP)' in 37 cases (18.5%) and other positions unsuitable for CCs in 99 cases (49.5%). Survival with favourable outcome at 3 months was 17.2% when 'supine position' had been applied, 13.5% with 'RP' and 6.1% with 'other positions unsuitable for CCs'; a statistically significant association could not be shown (p=0.740, Fisher's exact test). However, after 'effective CCs' favourable outcome at 3 months was 32.0% compared with 5.3% if no actions were taken. The OR was 5.87 (p=0.02). CONCLUSION: In OHCA, two-thirds of all victims were found in positions not suitable for effective CCs. This was associated with inferior outcomes. A substantial proportion of the victims was placed in RP. More attention should be paid to the correct positioning of victims in OHCA. This applies to CPR training for laypersons and dispatcher-assisted CPR.

[When to terminate resuscitation in adults?]. / Reanimation bei Erwachsenen: Wann kann eine Wiederbelebung beendet werden?

Resuscitation in cardiac arrest rarely results in survival with a good neurologic outcome. It is therefore a common problem to decide when resuscitation should not be initiated or an ongoing attempt has to be terminated. Resuscitation attempts should be withheld or terminated if there is a do not resuscitate order (DNR), if resuscitation is not in accordance with the presumptive will of the patient or does not have a chance to allow the patient to continue an independent living. As long as ventricular fibrillation or pulseless ventricular tachycardia are present, however, resuscitation should be continued. Also in pulmonary embolism prolonged resuscitation measures may be necessary. In out-of-hospital cardiac arrest resuscitation may be stopped when the three criteria are met: not witnessed arrest, no ventricular fibrillation or pulseless tachycardia, and no return of spontaneous circulation before arrival at the hospital. According to current guidelines in-hospital resuscitation can be terminated if the patient is in asystole for at least 20 minutes. In any case termination of a resuscitation attempt is an individual decision where all possible information on circumstances and on the patient should be taken into account.

[Role of coronary intervention after successful cardiopulmonary resuscitation]. / Die Rolle der Koronarintervention nach erfolgreicher kardiopulmonaler Reanimation.

Immediate coronary angiography and intervention in suitable stenoses in patients resuscitated from cardiac arrest of presumed coronary origin and return of spontaneous circulation is widely established in interventional centers. The procedure is based on the analogy of positive results achieved with coronary intervention in many forms of acute coronary syndromes on the one hand and otherwise from registries showing promising data from coronary intervention of resuscitated patients. Results from randomized controlled studies, however, are not yet available. With respect to ST-elevation myocardial infarction, the diagnostic reliability of an ECG registered shortly after cardiopulmonary resuscitation is sufficient. The results of the registries are specifically promising for patients with ST-elevation myocardial infarction but less favorable for other forms of acute coronary syndromes. Moreover, insight into the results of the registries reveals that patients with the best prognostic conditions were preferentially selected for coronary intervention (e.g., younger patients, those with an initially shockable arrhythmia, bystander resuscitation), whereas those, for example, with cardiac or renal failure were excluded. For better definition of the actual benefit of coronary intervention after resuscitation from cardiac arrest and the optimal target groups, randomized controlled studies on patients with ST-elevation myocardial infarction are desirable, while for other forms of acute coronary syndromes these studies are essential.

Double-blind, randomized, prospective comparison of loading doses of 600 mg clopidogrel versus 60 mg prasugrel in patients with acute ST-segment elevation myocardial infarction scheduled for primary percutaneous intervention: the ETAMI trial (early thienopyridine treatment to improve primary PCI in patients with acute myocardial infarction).

OBJECTIVES: This study compared the timing of onset of antiplatelet action after treatment with clopidogrel and prasugrel at first medical contact in patients with ST-segment elevation myocardial infarction (STEMI) scheduled for primary percutaneous coronary intervention (PPCI). BACKGROUND: Little is known about the timing of onset of antiplatelet action after a pre-percutaneous coronary intervention (PCI) loading dose of clopidogrel or prasugrel in patients with STEMI. METHODS: This double-blind, prospective study randomized 62 patients with STEMI scheduled for PPCI in the ambulance or the emergency department to 60 mg prasugrel (n = 31) or 600 mg clopidogrel (n = 31). The primary endpoint was the platelet reactivity index (PRI) measured with the vasodilator-stimulated phosphoprotein assay 2 h after intake of the study medication. Secondary endpoints were PRI after 4 h, TIMI (Thrombolysis In Myocardial Infarction) patency of the infarct-related artery before and after PCI, and clinical events until day 30. RESULTS: The PRI after 2 h (50.4 ± 32.7% vs. 66.3 ± 22.2%; p = 0.035) and after 4 h (39.1 ± 27.5% vs. 54.5 ± 49.3%; p = 0.038) were significantly lower with prasugrel compared with clopidogrel. In addition, the rate of patients with a PRI <50% tended to be higher with prasugrel compared with clopidogrel after 2 h (46.7% vs. 28.6%; p = 0.15) and after 4 h (63.0% vs. 38.9%; p = 0.06). There were no significant differences in TIMI 2/3 patency before PCI (39.2% vs. 31.0%; p = 0.43) and TIMI 3 patency after PCI (88.5% vs. 89.3%; p = 0.92). CONCLUSIONS: The pre-PCI administration of prasugrel in patients with STEMI undergoing PPCI was associated with a significant faster platelet inhibition compared with clopidogrel. Therefore, prasugrel should be preferred to clopidogrel in this setting. (ETAMI-Study: Early Thienopyridine Treatment to Improve Primary PCI in Patients With Acute Myocardial Infarction; NCT01327534).

Official lay basic life support courses in Germany: is delivered content up to date with the guidelines? An observational study.

BACKGROUND AND OBJECTIVES: Educating the lay public in basic life support (BLS) is a cornerstone to improving bystander cardiopulmonary resuscitation (CPR) rates. In Germany, the official rescue organisations deliver accredited courses based on International Liaison Committee on Resuscitation (ILCOR) guidelines to up to 1 million participants every year. However, it is unknown how these courses are delivered in reality. We hypothesised that delivered content might not follow the proposed curriculum, and miss recent guideline updates. METHODS: We analysed 20 official lay BLS courses of 240 min (which in Germany are always embedded into either a 1-day or a 2-day first aid course). One expert rated all courses as a participating observer, remaining incognito throughout the course. Teaching times for specific BLS elements were recorded on a standardised checklist. Quality of content was rated by 5-point Likert scales, ranging from -2 (not mentioned) to +2 (well explained). RESULTS: Median total course time was 101 min (range 48-138) for BLS courses if part of a 1-day first aid course, and 123 min (53-244) if part of a 2-day course. Median teaching time for CPR was 51 min (range 20-70) and 60 min (16-138), respectively. Teaching times for recovery position were 44 min (range 24-66) and 55 min (24-114). Quality of content was rated worst for 'agonal gasping' (-1.35) and 'minimising chest compression interruptions' (-1.70). CONCLUSIONS: Observed lay BLS courses lasted only half of the assigned curricular time. Substantial teaching time was spent on non-evidence-based interventions (eg, recovery position), and several important elements of BLS were not included. The findings call for curriculum revision, improved instructor training and systematic quality management.

Old age and chronic disease: is the emergency medical system the appropriate provider for the elderly?

OBJECTIVE: The use of emergency medical services increases with the age of patients. Some care providers hold on to the prejudice that these alarms are unnecessary or of a lower importance. We assessed the relation of age and age-dependent emergency characteristics, taking into consideration the ratings of emergency physicians on whether or not emergency cases were considered truly in need of emergency physician attendance. METHODS: Emergency physicians dispatched by the Berlin Fire Department evaluated for each case the necessity of emergency physician attendance. Case characteristics such as the day of the week and location of the emergency as well as patient characteristics such as age, sex, prior status, and care dependency were recorded. In addition, whether or not the physician accompanied the patient to the hospital was recorded as a parameter for emergency severity. Analysis was performed using multiple logistic regression modeling. RESULTS: During the 6-month prospective study period, 2702 cases were evaluated. Emergency medical services are used more frequently by older individuals, especially octogenarians. Emergency cases in older individuals were significantly more often rated as in need of emergency physician attendance; however, the rate of patients accompanied by the emergency physician to the hospital did not differ between the age groups. The age of patients, the primary diagnosis, the day and location of the emergency, and the presence of pre-existing dementia showed a significant impact on the necessity of physician-attended emergency missions. CONCLUSION: Despite common prejudices, emergency cases in elder patients are rated more often as in need of emergency physician attendance compared with those involving younger patients.

Impact of advanced age on myocardial perfusion, distal embolization, and mortality patients with ST-segment elevation myocardial infarction treated by primary angioplasty and glycoprotein IIb-IIIa inhibitors.

Despite mechanical reperfusion, the outcome is still unsatisfactory in elderly patients with ST-segment elevation myocardial infarction (STEMI). The vast majority of studies have been conducted without extensive use of glycoprotein (Gp) IIb-IIIa inhibitors, which have been associated with improved perfusion and survival. Thus the aim of the current study was to evaluate the impact of age on the angiographic and clinical outcome patients with STEMI undergoing primary angioplasty with Gp IIb-IIIa inhibitors. Our population is represented by a total of 1,662 patients undergoing primary angioplasty for STEMI included in 11 randomized trials comparing early versus late administration of Gp IIb-IIIa inhibitors. Myocardial perfusion was evaluated by myocardial blush grade and ST-segment resolution. Follow-up data were collected between 30 days and 1 year after primary angioplasty. A total of 231 (13.9 %) patients were older than 75 years. Elderly patients showed a larger prevalence of female gender, hypertension, and diabetes, more advanced Killip class at presentation and longer time to treatment, but a smaller prevalence of smoking. All patients were treated with GP IIb-IIIa inhibitors. Elderly patients showed a significantly impaired postprocedural thrombolysis in myocardial infarction (TIMI) flow (TIMI 0-2: 17.7 vs 10.3 %, P = 0.002) and myocardial perfusion (myocardial blush grade 0-1: 38.3 vs 26.5 %, P = 0.001), and higher prevalence of distal embolization (19.2 vs 9.8 %, P < 0.001), whereas no difference was observed in terms of ST-segment resolution. At follow-up, elderly patients showed a significantly higher mortality (3.2 vs 11.0 %, hazard ratio (HR) (95 % confidence interval (CI)) = 3.78 (2.31-6.16), P < 0.001), which was confirmed after adjustment for baseline confounding factors (HR (95 % CI) = 5.01 (2.63-9.55), P < 0.0001). This study showed that among patients with STEMI undergoing primary angioplasty, advanced age is an independent predictor of mortality after primary angioplasty. Higher rates of distal embolization and poor myocardial perfusion, in addition to the worse risk profile, contribute toward explaining the impact of aging on mortality.

Impact of hypertension on distal embolization, myocardial perfusion, and mortality in patients with ST segment elevation myocardial infarction undergoing primary angioplasty.

Hypertension is a well-known risk factor for atherosclerosis. However, data on the impact of hypertension in patients with ST elevation myocardial infarction (STEMI) are inconsistent and mainly related to studies performed in the thrombolytic era, with very few data on patients undergoing primary angioplasty. The aim of the present study was to evaluate the impact of hypertension on distal embolization, myocardial perfusion, and mortality in patients with STEMI undergoing primary percutaneous coronary intervention. Our population is represented by 1,662 patients undergoing primary angioplasty for STEMI included in the Early Glycoprotein IIb-IIIa inhibitors in Primary angioplasty database. Myocardial perfusion was evaluated by myocardial blush grade and ST segment resolution. Follow-up data were collected within 1 year after primary angioplasty. Hypertension was observed in 700 patients (42.1%). Hypertension was associated with more advanced age (p <0.001), female gender (p <0.001), diabetes (p <0.001), hypercholesterolemia (p <0.001), previous revascularization (p <0.001), anterior myocardial infarction (p = 0.006), longer ischemia time (p = 0.03), more extensive coronary artery disease (p = 0.002), more often treated with abciximab (p <0.001), and less often smokers (p <0.001). Hypertension was associated with impaired postprocedural myocardial blush grade 2 to 3 (68.2% vs 74.2%, p = 0.019) and complete ST segment resolution (51.7% vs 61.1%, p = 0.001). By a mean follow-up of 206 ± 158 days, 70 patients (4.3%) had died. Hypertension was associated with a greater mortality (6.2% vs 2.9%, hazard ratio 2.31, 95% confidence interval 1.42 to 3.73, p <0.001), confirmed after correction for baseline confounding factors (hazard ratio 1.82, 95% confidence interval 1.03 to 3.22, p <0.001). In conclusion, this study showed that among patients with STEMI undergoing primary angioplasty, hypertension is associated with impaired reperfusion and independently predicts 1-year mortality.

Impact of multivessel disease on myocardial perfusion and survival among patients undergoing primary percutaneous coronary intervention with glycoprotein IIb/IIIa inhibitors.

BACKGROUND: Although primary angioplasty achieves thrombolysis in myocardial infarction (TIMI) 3 flow in most patients with ST-elevation myocardial infarction, epicardial recanalization does not guarantee optimal perfusion in a large proportion of patients. The influence of multivessel disease on myocardial reperfusion and survival after primary angioplasty has not been extensively investigated. AIM: To evaluate the impact of multivessel disease on myocardial perfusion and survival in a large cohort of patients with ST-elevation myocardial infarction treated with angioplasty and glycoprotein (GP) IIb/IIIa inhibitors. METHODS: This analysis is based on 1494 patients undergoing primary angioplasty included in the EGYPT database. Myocardial perfusion was evaluated by angiography or ST-segment resolution, whereas infarct size was estimated by using peak creatine kinase-MB (CK-MB). Follow-up data were collected between 30 days and 1 year after primary angioplasty. RESULTS: Multivessel disease was observed in 870 patients (58.2%). The extent of coronary artery disease was associated with age, diabetes, hypertension, previous myocardial infarction, previous revascularization, abciximab treatment and longer ischaemic time, and was independently associated with impaired angiographic myocardial perfusion (adjusted odds ratio 1.18, 95% confidence interval [CI] 1.01-1.40, P=0.049). At 208±160 days, the extent of coronary artery disease was independently associated with higher mortality (adjusted hazard ratio 1.54, 95% CI 1.06-2.24, P=0.022). CONCLUSIONS: Among patients with ST-elevation myocardial infarction undergoing primary angioplasty with GP IIb/IIIa inhibitor treatment, the extent of coronary artery disease was independently associated with impaired myocardial perfusion and survival.

Fibrinolysis or primary PCI in ST-segment elevation myocardial infarction.

BACKGROUND: It is not known whether prehospital fibrinolysis, coupled with timely coronary angiography, provides a clinical outcome similar to that with primary percutaneous coronary intervention (PCI) early after acute ST-segment elevation myocardial infarction (STEMI). METHODS: Among 1892 patients with STEMI who presented within 3 hours after symptom onset and who were unable to undergo primary PCI within 1 hour, patients were randomly assigned to undergo either primary PCI or fibrinolytic therapy with bolus tenecteplase (amended to half dose in patients ≥75 years of age), clopidogrel, and enoxaparin before transport to a PCI-capable hospital. Emergency coronary angiography was performed if fibrinolysis failed; otherwise, angiography was performed 6 to 24 hours after randomization. The primary end point was a composite of death, shock, congestive heart failure, or reinfarction up to 30 days. RESULTS: The primary end point occurred in 116 of 939 patients (12.4%) in the fibrinolysis group and in 135 of 943 patients (14.3%) in the primary PCI group (relative risk in the fibrinolysis group, 0.86; 95% confidence interval, 0.68 to 1.09; P=0.21). Emergency angiography was required in 36.3% of patients in the fibrinolysis group, whereas the remainder of patients underwent angiography at a median of 17 hours after randomization. More intracranial hemorrhages occurred in the fibrinolysis group than in the primary PCI group (1.0% vs. 0.2%, P=0.04; after protocol amendment, 0.5% vs. 0.3%, P=0.45). The rates of nonintracranial bleeding were similar in the two groups. CONCLUSIONS: Prehospital fibrinolysis with timely coronary angiography resulted in effective reperfusion in patients with early STEMI who could not undergo primary PCI within 1 hour after the first medical contact. However, fibrinolysis was associated with a slightly increased risk of intracranial bleeding. (Funded by Boehringer Ingelheim; ClinicalTrials.gov number, NCT00623623.).

Time-related impact of distal embolisation on myocardial perfusion and survival among patients undergoing primary angioplasty with glycoprotein IIb-IIIa inhibitors: insights from the EGYPT cooperation.

AIMS: Considerable interest has been focused in recent years on the role of distal embolisation as a major determinant of impaired reperfusion after primary angioplasty for STEMI. The aim of the current study was to evaluate in a large cohort of STEMI patients undergoing primary angioplasty with glycoprotein (Gp) IIb-IIIa inhibitors, whether the impact of distal embolisation on myocardial perfusion and survival may depend on time-to-treatment. METHODS AND RESULTS: Our population is represented by 1,182 patients undergoing primary angioplasty for STEMI included in the EGYPT database. Patients were grouped according to time-to-treatment (<3 hours, 3-6 hours, >6 hours). Distal embolisation was defined as an abrupt "cutoff" in the main vessel or one of the coronary branches of the infarct-related artery, distal to the angioplasty site. Myocardial perfusion was evaluated by angiography or ST-segment resolution, whereas infarct size was estimated by using peak creatine kinase (CK) and CK-MB. Follow-up data were collected between 30 days and one year after primary angioplasty. Distal embolisation was observed in 132 patients (11.1%) and tended to occur more frequently in late presenters (p=0.067). Patients with distal embolisation less often had post-procedural Thrombolysis In Myocardial Infarction (TIMI) 3 flow (p<0.001), post-procedural myocardial blush grade (MBG) 2-3 (p<0.001), complete ST-segment resolution (p=0.021) and larger infarct size (p=0.012). Distal embolisation was associated with a significantly higher mortality (9.2% vs. 2.7%, heart rate [HR] [95% CI]=3.41 [1.73-6.71], p<0.0001). The impact of distal embolisation on myocardial perfusion and survival persisted for all time intervals. CONCLUSIONS: This study showed that among STEMI patients treated with Gp IIb-IIIa inhibitors, the negative impact of distal embolisation on myocardial perfusion and mortality is independent of the time from symptom onset to balloon angioplasty.

Fate of patients with prehospital resuscitation for ST-elevation myocardial infarction and a high rate of early reperfusion therapy (results from the PREMIR [Prehospital Myocardial Infarction Registry]).

Patients with acute ST-segment elevation myocardial infarction (STEMI) needing prehospital cardiopulmonary resuscitation (CPR) have a very high adverse-event rate. However, little is known about the fate of these patients and predictors of mortality in the era of early reperfusion therapy. From March 2003 through December 2004, 2,317 patients with prehospital diagnosed STEMI were enrolled in the Prehospital Myocardial Infarction Registry. One hundred ninety patients (8.2%) underwent prehospital CPR and were included in our analysis. Overall 90% of patients were treated with early reperfusion therapy, 56.3% received prehospital thrombolysis and 1/2 of these patients received early percutaneous coronary intervention after thrombolysis, 28.4% of patients were treated with primary percutaneous coronary intervention, and 5.3% received in-hospital thrombolysis. Total mortality was 40.0%. The highest mortality was seen in patients with asystole (63%) or pulseless electric activity (64%). Independent predictors of mortality were need for endotracheal intubation and older age, whereas ventricular fibrillation as initial heart rhythm was associated with survival. In conclusion, in this large registry with prehospital diagnosed STEMI, incidence of prehospital CPR was about 8%. Even with a very high rate of early reperfusion therapy, in-hospital mortality was high. Especially in elderly patients with asystole as initial heart rhythm and with need for endotracheal intubation, prognosis is poor despite aggressive reperfusion therapy.

Efficacy and safety of a high loading dose of clopidogrel administered prehospitally to improve primary percutaneous coronary intervention in acute myocardial infarction: the randomized CIPAMI trial.

OBJECTIVES: To compare a loading dose of 600 mg clopidogrel given in the prehospital phase versus clopidogrel administered only after the diagnostic angiogram in patients with STEMI scheduled for primary PCI. BACKGROUND: The optimal time and dose for the initiation of clopidogrel therapy in patients with STEMI scheduled for primary PCI has not been studied in prospective randomized trials. METHODS: The primary efficacy endpoint was the TIMI 2/3 patency of the infarct-related artery in the diagnostic angiography immediately prior to PCI. RESULTS: We randomized 337 patients to prehospital (n = 166) loading dose versus standard therapy (n = 171). The time interval between initiation of clopidogrel therapy and diagnostic angiography was 47 min. TIMI 2/3 patency before PCI was not different between the groups (49.3 vs. 45.1%, P = 0.5). We observed a trend towards a reduction of the combined endpoint death, re-infarction, and urgent target vessel revascularization in the prehospital-treated patients (3.0 vs. 7.0%, P = 0.09), this difference was significant if patients were classified as treated (4/161 vs. 13/174; 2.5 vs. 7.5%, P < 0.05). There was no difference in TIMI major bleeding complications (9.1 vs. 8.2%, P = 0.8). CONCLUSIONS: Early inhibition of the platelet ADP-receptor with a high loading dose of 600 mg clopidogrel given in the prehospital phase in patients with STEMI scheduled for primary PCI is safe, did not increase pre-PCI patency of the infarct vessel, but was associated with a trend towards a reduction in clinical events.

Expertise in prehospital endotracheal intubation by emergency medicine physicians-Comparing 'proficient performers' and 'experts'.

BACKGROUND: Training requirements to perform safe prehospital endotracheal intubation (ETI) are not clearly known. This study aimed to determine differences in ETI performance between 'proficient performers' and 'experts' according to the Dreyfus & Dreyfus framework of expertise. As a model for 'proficient performers' EMS physicians with a clinical background in internal medicine were compared to EMS physicians with a background in anaesthesiology as a model for 'experts'. METHODS: Over a one-year period all ETIs performed by the EMS physicians of our institution were prospectively evaluated. 'Proficient performers' and 'experts' were compared regarding incidence of difficult ETI, ability to predict difficult ETI, and decision for ETI. RESULTS: Mean years of professional experience were similar between the physician groups, but the median ETI experience differed significantly with 18/year for 'proficients' and 304/year for 'experts' (p<0.001). 'Proficient performers' intubated 130 of their 2170 treated patients (6.0%), while 'experts' did so in 146 of 1809 cases (8.1%, p=0.01 for difference). The incidence of difficult ETI was 17.7% for 'proficient performers', and 8.9% for 'experts' (p<0.05). In 4 cases ETI was impossible, all managed by 'proficient performers', but all patients could be ventilated sufficiently. Unexpected difficult ETI occurred in 6.1% for 'proficient performers', and 2.0% for 'experts' (p=0.08). CONCLUSIONS: In a prehospital setting 'expert' status was associated with a significantly lower incidence of 'difficult ETI' and a higher proportion of ETI decisions. In addition, ability to predict difficult ETI was higher, although non-significant. There was no difference in the incidence of impossible ventilation.

Difficult prehospital endotracheal intubation - predisposing factors in a physician based EMS.

OBJECTIVES: For experienced personnel endotracheal intubation (ETI) is the gold standard to secure the airway in prehospital emergency medicine. Nevertheless, substantial procedural difficulties have been reported with a significant potential to compromise patients' outcomes. Systematic evaluation of ETI in paramedic operated emergency medical systems (EMS) and in a mixed physician/anaesthetic nurse EMS showed divergent results. In our study we systematically assessed factors associated with difficult ETI in an EMS exclusively operating with physicians. METHODS: Over a 1-year period we prospectively collected data on the specific conditions of all ETIs of two physician staffed EMS vehicles. Difficult ETI was defined by more than 3 attempts or a difficult visualisation of the larynx (Cormack and Lehane grade 3, or worse). For each patient ETI conditions, biophysical characteristics and factors of the surrounding scene were assessed. Additionally, physicians were asked whether they had expected difficult ETI in advance. RESULTS: Out of 3979 treated patients 305 (7.7%) received ETI. For 276 patients complete data sets were available. The incidence of difficult ETI was 13.0%. In 4 cases (1.4%) ETI was impossible, but no patient was unable to be ventilated sufficiently. Predicting conditions for difficult intubation were limited surrounding space on scene (p<0.01), short neck (p<0.01), obesity (p<0.01), face and neck injuries (p<0.01), mouth opening<3 cm (p<0.01) and known ankylosing spondylitis (p<0.01). ETI on the floor or with C-spine immobilisation in situ were of no significant influence. The incidence of unexpected difficult ETI was 5.0%. CONCLUSIONS: In a physician staffed EMS difficult prehospital ETI occurred in 13% of cases. Predisposing factors were limited surrounding space on scene and certain biophysical conditions of the patient (short neck, obesity, face and neck injuries, and anatomical restrictions). Unexpected difficult ETI occurred in 5% of the cases.