Dr Willi Schmidbauer
+49 (0)89 2841 2053
Pre-hospital use of non-invasive ventilation improves acute respiratory failure: a randomised controlled trial
Non-invasive ventilation (NIV) is used as ventilatory support without endotracheal intubation to spontaneously breathing patients and has been demonstrated to be feasible during hospital treatment of several forms of acute respiratory failure.
The aim of this study is to determine whether the early pre-hospital use of an emergency ventilator, enabling application of continuous positive airway pressure (CPAP) or non-invasive positive pressure ventilation (NIPPV) - according to clinical demand - is practicable and will improve dyspnoea.
Ethics Committee of Charite - University Medicine Berlin gave approval (ref: EA1/140/06)
Prospective randomised pilot study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Acute respiratory failure
Patients were assigned to one of two groups by closed envelope randomisation:
1. NIV (intervention group)
2. Standard oxygen therapy via face mask (control group)
In both groups, basic therapy included fenoterol, reproterol, terbutaline, prednisolone, theophylline, furosemide, nitroglycerin, and morphine according to clinical necessity and local standard operating procedures. Pre-hospital monitoring consisted of non-invasive arterial blood pressure, continuous pulse oxymetry, continuous electrocardiography (ECG), and 12-channel ECG.
The dyspnoea score measures the dyspnoea as declared by the patient with a range from 1 (no dyspnoea) to 10 (worst dyspnoea with the feeling of asphyxiation).
In addition to the above mentioned drug treatment, patients of the NIV group were initially supplied with CPAP of 5 cm H2O and an inspiratory oxygen fraction (FiO2) of 0.5 (Oxylog® 3000, Draeger Medical, Germany). NIV was applied via face mask, as this has been shown to be favourable compared to nasal masks. Goals of NIV therapy were improvement of dyspnoea score, reduction of respiratory rate less than 25/min, increase of SpO2 greater than 90%, decrease of and acceptance by the patients. In case of failure to reach these treatment goals, CPAP was increased primarily to 7.5 cm H2O and secondarily to 10 cm H2O. Next step of escalation was an additional application of pressure support of 5 cm H2O in the NIPPV modus. If necessary, pressure support was increased by steps of 5 cm H2O up to a peak inspiratory pressure (CPAP + pressure support) of 30 cm H2O. Last step of escalation of NIV treatment was an increase of FiO2 to 1.0. In case of failing the above mentioned goals or intolerance by the patient, NIV treatment was stopped and patient was excluded.
Patients of the control group were supplied by oxygen inhalation via face mask up to 12 l/min. In both groups endotracheal intubation was performed according physicians decision.
Fenoterol, reproterol, terbutaline, prednisolone, theophylline, furosemide, nitroglycerin, morphine
Primary outcome measure
Rate of endotracheal intubation during first 24 hours of treatment.
Secondary outcome measures
1. Difference of baseline and admission values of:
1.1. Pulse oxymetric oxygen saturation
1.2. Respiratory rate
1.3. Dyspnoea score
1.4. Heart rate
1.5. Systolic diastolic arterial blood pressure
2. Duration of intensive care
3. Incidence and duration of mechanical ventilation, and hospital days
4. Feasibility of NIV was rated at a scale from 1 to 5 (very good, good, acceptable, difficult, not feasible)
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Aged above 18 years, either sex
2. Acute dyspnoea
3. Respiratory rate greater than 25/min
4. Pulse oxymetric oxygen saturation less than 90%
Target number of participants
Participant exclusion criteria
1. Refusal of NIV
3. Glasgow Coma Scale less than 12 points
4. Suspected myocardial ischaemia
5. Systolic blood pressure less than 100 mmHg
7. Injury of face or neck
8. Participation in another study
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Medical Service of the Bundeswehr (Sanitätsamt der Bundeswehr [SanABw]) (Germany) (ref: 03 K4-S-170607)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
2011 results in http://www.ncbi.nlm.nih.gov/pubmed/20844095
Schmidbauer W, Ahlers O, Spies C, Dreyer A, Mager G, Kerner T, Early prehospital use of non-invasive ventilation improves acute respiratory failure in acute exacerbation of chronic obstructive pulmonary disease., Emerg Med J, 2011, 28, 7, 626-627, doi: 10.1136/emj.2009.089102.