Before and after studies and historical controls. Is the proof in the pudding?

Big data: Airway management at a university hospital over 16 years; a retrospective analysis

Purpose

Little is known about the current practice of airway management in Germany and its development over the last decades. The present study was, therefore, designed to answer the following questions. Which airway management procedures have been performed over the last 16 years and how has the frequency of these procedures changed over time? Is there a relationship between patient characteristics or surgical specialisation and the type of airway management performed?

Methods

In the present study, we used our in-house data acquisition and accounting system to retrospectively analyse airway management data for all patients who underwent a surgical or medical procedure with anaesthesiological care at our tertiary care facility over the past 16 years. 340,748 airway management procedures were analysed by type of procedure, medical/surgical specialty, and type of device used. Logistic regression was used to identify trends over time.

Results

Oral intubation was the most common technique over 16 years (65.7%), followed by supraglottic airway devices (18.1%), nasal intubation (7.5%), mask ventilation (1.6%), tracheal cannula (1.3%), double lumen tube (0.7%), and jet ventilation (0.6%). On average, the odds ratio of using supraglottic airway devices increased by 17.0% per year (OR per year = 1.072, 95% CI = 1.071–1.088) while oral intubation rates decreased. In 2005, supraglottic airway devices were used in about 10% of all airway management procedures. Until 2020, this proportion steadily increased by 27%. Frequency of oral intubation on the other hand decreased and was about 75% in 2005 and 53% in 2020.

Over time, second-generation supraglottic airway devices were used more frequently than first-generation supraglottic airway devices. While second-generation devices made up about 9% of all supraglottic airway devices in 2010, in 2020 they represented a proportion of 82%.

The use of fibreoptic intubation increased over time in otorhinolaryngology and dental, oral, and maxillofacial surgery, but showed no significant trends over the entire 16-year period.

Conclusion

Our data represent the first large-scale evaluation of airway management procedures over a long time. There was a significant upward trend in the use of supraglottic airway devices, with an increase in the use of second-generation masks while a decrease in oral intubations was observed.

Study Designs in Clinical Research

Background: The quality of scientific literature is judged by study design, validity, and applicability to unique patient populations. Methods: We searched the available literature to explore the hierarchy of evidence, explain research fundamentals such as sample size calculation, and discuss common study designs employed in surgical research and the interpretation of trial designs. Results: Each unique study design has restraints created by some degree of systematic errors and bias. This article provides definitions for the scientific boundaries of case control, retrospective, before-and-after, prospective observational, randomized controlled designs, and meta-analyses. Conclusion: Critical thinking and appraisal of the literature is a skill that requires lifelong training and practice. Clinical research education and design need to garner more attention in the medical community.