Airway management research: a systematic review.

Recent controversy regarding the ethics of conducting airway research in patients led to disagreements concerning the value and frequency of manikin-based investigation. However, no formal examination of the methodology of airway research has been undertaken. We, therefore, performed a systematic bibliometric review of airway management research to describe the conduct, quantify the subjects (patient vs. manikin vs. other), assess the reported outcomes and map global trends. We retrieved 1505 relevant studies published between 2006 and 2017, together recruiting 359,648 subjects, of which 341,233 were patients, the remaining being volunteers or subjects managing manikins, human cadavers, animals or bench models. There were 701 randomised controlled clinical trials (46.6%), 83 non-randomised experimental clinical trials (5.5%), 298 observational studies (19.8%) and 423 non-patient studies (28.1%). A total of 1082 studies (71.9%) were patient studies and 322 were manikin studies (21.4%). The total annual number of airway management studies increased over time, as did the annual number of patient studies, but there was no significant increase in the annual number of manikin studies over time. Of the patient studies, subject baseline characteristics were most likely to be ASA status 1-2 (n = 531, 49.1%), populations were most often elective surgical patients (n = 918, 84.8%) and the most common interventions studied were tracheal intubation (n = 820, 54.4%) or supraglottic airway device insertion (n = 257, 17.1%). There was a total of 77 different primary outcomes used in the included studies, the most commonly reported being success rate and procedure time. By understanding how and what has been previously studied these data can be used to form the basis for future priority setting exercises, core outcome set development, and could inform strategy on the future directions of airway management research.