Effectiveness and safety of a prehospital program of continuous positive airway pressure (CPAP) in an urban setting

Abstract

Background: Continuous positive airway pressure (CPAP) is commonly used in the treatment of acute cardiogenic pulmonary edema (ACPE) and acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In-hospital evidence is robust: CPAP has been shown to improve respiratory status and to reduce intubation rates. There is less evidence on prehospital CPAP, although the emergency medical services (EMS) adoption of this modality is increasing. The objectives of this study were to 1) measure the effectiveness of prehospital CPAP on morbidity, mortality, and transport times; and 2) audit the selection of patients by medics for appropriateness and safety. Methods: We conducted a before-and-after study from August 1 to October 31 in 2010 and 2011, before and after the implementation of prehospital CPAP in a city of one million people with large rural areas. Medics were trained to apply CPAP to patients with respiratory distress and a presumed diagnosis of ACPE or AECOPD. Charts were selected using the search criteria of the chief complaint of shortness of breath, emergent transport to hospital, and any patients receiving CPAP in the field. Data extracted from ambulance call reports and hospital records were analysed with appropriate univariate statistics. Results: A total of 373 patients enrolled (186 pre-non-invasive ventilation [NIV] and 187 post-NIV), mean age 71.5 years, female 51.4%, and final diagnoses of ACPE 18.9%, AECOPD 21.9%. In the post group of 84 patients meeting NIV criteria, 41.6% received NIV; and of 102 patients not meeting the criteria, 5.2% received NIV. There were 12 minor adverse events in 36 applications (33.3%) as per protocol. Comparing post versus pre, there were higher rates of emergency department (ED) NIV (20.0% v. 13.4%, p < 0.0001) and higher overall mortality (18.8% v. 14.9%, p < 0.0001). There were no differences in ED intubation (2.1% v. 2.3%, p < 0.001) and length of stay (6.8 v. 8.7 days, p = 0.24). Conclusion: Despite the robust in-hospital data supporting its use, we could not find benefit from CPAP in our prehospital

Is a definitive trial of prehospital continuous positive airway pressure versus standard oxygen therapy for acute respiratory failure indicated? The ACUTE pilot randomised controlled trial

“…Medical Services (EMS). [20][21][22][23][24] These studies are consistent with the ACUTE experience of submaximal CPAP adherence and difficult prehospital diagnosis, including treatment of patients with pneumothoraces. A recent systematic review identified 10 trials and quasi-randomised studies comparing prehospital NIV (including CPAP) with standard oxygen therapy.…”

Prehospital treatment with continuous positive airway pressure in patients with acute respiratory failure: a regional observational study

“…The study protocols aimed at patients with presumed heart failure, COPD or asthma and the study patients’ initial oxygen saturation and respiratory rate were comparable to initial values in this study population. Transport time from departure from scene to arrival at emergency department was considerably shorter than in the present study, only 9.6 min [ 30 ]. Distance and transport time to hospital is an important factor when deciding how to treat patients with acute respiratory failure during ambulance transport; it is always a balance between time used to initiate a prehospital treatment and a faster arrival to definitive treatment at hospital.…”

“…Comparison of standard medical therapy plus CPAP to standard medical therapy alone has shown, that CPAP is superior when using SpO 2 or respiratory rate as outcome measures of effectiveness in patients with acute cardiopulmonary oedema or acute respiratory failure [ 10 , 12 , 17 ]. Two recent studies of prehospital patients with respiratory distress, conducted in North American urban settings, did not find any benefit of CPAP when comparing groups before and after implementation [ 30 , 31 ]. The study protocols aimed at patients with presumed heart failure, COPD or asthma and the study patients’ initial oxygen saturation and respiratory rate were comparable to initial values in this study population.…”

Non-invasive Positive Pressure Ventilation for Acute Cardiogenic Pulmonary Edema and Chronic Obstructive Pulmonary Disease in Prehospital and Emergency Settings

“…Prehospital non-invasive ventilation can be effective in treating acute exacerbation of COPD and cardiogenic pulmonary edema. Six studies [3,7,8,15,18,19] were reviewed for the effectiveness of prehospital or out-of-hospital use of CPAP for reducing mortality intubation rates and hospital stay length. Reducing endotracheal intubation rate in other ways helps in reducing the risk of ventilator-associated pneumonia, length of hospital stay, and mortality.…”

“…One systematic review [3], three randomized control trials [7,8,15], and two observational studies [18,19] were taken into account for review. A systematic review done by Bakke et al [3] showed a great decrease in intubation rates when CPAP is given in prehospital settings but no reduction in mortality and length of hospital stays.…”