Randomised controlled trials (RCTs) and quasi-RCTs that compared tracheal intubation with alternative airway techniques involving paramedics in advanced airway management in the pre-hospital setting were eligible for inclusion. Alternative airway techniques were limited to bag-mask ventilation or extra-glottic devices. Paramedics were defined as any clinician who provided pre-hospital care (excluding physicians, nurses and respiratory therapists). One of the following outcomes had to be reported for inclusion: survival, neurologic outcomes, airway management success rates or complications. The following complications were assessed: rates of hypoxaemia (saturated oxygen and oxygen partial pressure), hypercarbia (carbon dioxide partial pressure), hypotension and aspiration.
Most of the included patients were in cardiac and/or respiratory arrest. Most included trials were of adults only; one was children only. Most trials compared tracheal intubation with extra-glottic devices; one trial in paediatric patients compared tracheal intubation with bag-mask ventilation. All trials provided additional airway training to the paramedics involved in the trial. One trial was conducted in a rural setting.
Studies were selected independently by two reviewers and disagreements were resolved with a third reviewer.