title: Prehospital treatment with continuous positive airway pressure in patients with acute respiratory failure: a regional observational study.
abstract: BACKGROUND
  Patients with acute respiratory failure are at risk of deterioration during prehospital transport. Ventilatory support with continuous positive airway pressure (CPAP) can be initiated in the prehospital setting. The objective of the study is to evaluate adherence to treatment and effectiveness of CPAP as an addition to standard care.
  
  
  METHODS
  In North Denmark Region, patients with acute respiratory failure, whom paramedics assessed as suffering from acute cardiopulmonary oedema, acute exacerbation of chronic obstructive pulmonary disease or asthma were treated with CPAP using 100 % O2from 1 March 2014 to 3 May 2015. Adherence to treatment was evaluated by number of adverse events and discontinuation of treatment. Intensive care admissions and mortality were reported in this cohort. Effectiveness was evaluated by changes in peripheral oxygen saturation (SpO2) and respiratory rate during transport and compared to a historical control (non-CPAP) group treated with standard care only. Values were compared by hypothesis testing and linear modelling of SpO2on arrival at scene and ΔSpO2stratified according to treatment group.
  
  
  RESULTS
  In fourteen months, 171 patients were treated with CPAP (mean treatment time 35 ± 18 min). Adverse events were reported in 15 patients (9 %), hereof six discontinued CPAP due to hypotension, nausea or worsening dyspnoea. One serious adverse event was reported, a suspected pneumothorax treated adequately by an anaesthesiologist called from a mobile emergency care unit. Among CPAP patients, 45 (27 %) were admitted to an intensive care unit and 24 (14 %) died before hospital discharge. The non-CPAP group consisted of 739 patients. From arrival at scene to arrival at hospital, CPAP patients had a larger increase in SpO2than non-CPAP patients (87 to 96 % versus 92 to 96 %, p < 0.01) and a larger decrease in respiratory rate (32 to 25 versus 28 to 24 breaths/min, p < 0.01). In a linear model, CPAP was superior to non-CPAP in patients with initial SpO2≤90 % (p < 0.05). One CPAP patient (0.6 %) and eight non-CPAP patients (1.1 %) were intubated in the prehospital setting.
  
  
  CONCLUSIONS
  The study design reflects the daily prehospital working environment including long transport timesand paramedics educated in treating symptoms of acute respiratory failure, rather than treating one specific diagnosis. The study population was included consecutively and few patients were lost to follow-up. However, the study was too small to allow assessment of any effect of prehospital CPAP on mortality, nor could the effectiveness in specific disease conditions be examined.
  
  
  CONCLUSIONS
  In an emergency medical service including physician backup, adherence to CPAP treatment administered by paramedics was high and treatment was effective in patients with acute respiratory failure.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Aalborg University Hospital, Aalborg, Denmark. vibe.n@rn.dk.|Department of Clinical Medicine, Aalborg University, Aalborg, Denmark. vibe.n@rn.dk.
authors.forename: Vibe Maria Laden
authors.initials: VM
authors.lastname: Nielsen
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Madsen
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Anette
authors.initials: A
authors.lastname: Aasen
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Aalborg University Hospital, Aalborg, Denmark.|Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
authors.forename: Anne Pernille
authors.initials: AP
authors.lastname: Toft-Petersen
authors.affiliation: Prehospital Emergency Medical Services, North Denmark Region, Aalborg, Denmark.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Lübcke
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Aalborg University Hospital, Aalborg, Denmark.|Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
authors.forename: Bodil Steen
authors.initials: BS
authors.lastname: Rasmussen
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Aalborg University Hospital, Aalborg, Denmark.|Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.|Prehospital Emergency Medical Services, North Denmark Region, Aalborg, Denmark.
authors.forename: Erika Frischknecht
authors.initials: EF
authors.lastname: Christensen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000552:Ambulances; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D003718:Denmark / Q000453:epidemiology; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000401:mortality / Q000628:therapy*; D015996:Survival Rate / Q000639:trends; D013997:Time Factors
keywords: CPAP; Continuous positive airway pressure; Dyspnea; Emergency medical services; Noninvasive ventilation; Paramedic; Prehospital; Respiratory insufficiency