Quality Control In Critical Care Training By Zyllan Spilsbury (F2)

Contents Background Search criteria The paper Summary Validity Methodology Results Discussion

The Problem: Intubation and acute airway management training for trainees. Learning curve vs. Kantian Ideal How do you find balance?

What to do with airways? Preparation Pre-oxygenation Premedication Paralysis Placement Post management

The Search:

The Search

Paper: The Usefulness of Design of Experimentation in Defining the Effect Difficult Airway Factors and Training Have on Simulator Oral-Tracheal Intubation Success Rates in Novice Intubators Frank Thomas, Judi Carpenter, Carol Rhoades, Renee Holleran, Gregory Snow Academic Emergency Medicine Journal – 2010; doi: /j x

The study: Full Factorial design of experimentation – Six factors (Straight vs curved blade, trismus, tongue oedema, laryngeal spasm, pharyngeal obstruction and cervical immobilization) 64 airway scenarios were randomly assigned to 12 nurses (single blinded) First pass intubation rates and tracheal intubation time before and after didactic training Statistics: – Binary variable with intubation success measured as a linear model. – Two way interactions between the six factors

Validity Population – 12 Critical Care Transport Nurses (novice intubator) – Recruitment bias – Small study Intervention – 4 hour didactic intubation training – 5 attempts at normal (grade 1) intubation Comparison – Before and after training; – Null- Intubation success would not change between different difficult airway scenarios in the pre and post training cohorts Outcome – First pass tracheal/oesophageal intubation rates – Tracheal Intubation time (laryngoscope entry to 3 successful breaths) Study set out to detect a beneficial effect No conflict of interests noted

Methodology Use of a model “Laerdal difficult airway simulator” 64 different airway scenarios – Randomized Single blind study. Only randomized the first time. Bias. – How were they different? – Unknown how many scenarios each person underwent? Training process- – 4hour program including airway adjuncts, RSI, observation of instructional video and 5 successful attempts at intubating the model 3 month process from start to finish- – Other confounders?

Results Normal probability plots created to test the null hypothesis based on predictions Straight blade, tongue oedema and laryngeal spasm all reduced first pass intubation. (p<0.01) No difference in trismus, pharyngeal obstruction or cervical immobilization. 1st attemptintubation TrachealOesophagealMean Tracheal Intubation Time Pre training19%17%97 seconds Post training36%16%81 seconds

Results- Reliability All p values and CIs stated Standard deviations for time to intubate quoted but large. No statistical analysis of previous experience as confounder. All figures are expressed as proportions (%) – How big were the sample sizes? Wrong statistical test used for first attempt intubation – Chi squared instead of normal distribution analysis

Relevance Strange to assess “straight blade” as a “difficult airway” Intubation time is an odd thing to measure as it will not necessarily correspond to safety Assuming the results are robust: – Significant increase in first time intubation rates and times following training on a model. – Training on a model did not adversely affect intubation rate. Specific study population-> results may differ in Drs or Anaesthetic trainees. No Control. How good can models be compared to the real thing?

Conclusions Impossible to form perfect study as models are no substitute for humans Small study group Poorly randomized Poor presentation of results (proportions) Unusual outcomes Odd statistical testing Improvement in first pass intubation rate by training Good idea but poor delivery

Many Thanks! Special Mention to Victoria Treadway. References: 1) The Usefulness of Design of Experimentation in Defining the Effect Difficult Airway Factors and Training Have on Simulator Oral-Tracheal Intubation Success Rates in Novice Intubators. Frank Thomas, Judi Carpenter, Carol Rhoades, Renee Holleran, Gregory Snow. Academic Emergency Medicine Journal. 2010; doi: /j x 2) Difficult airway society guidelines 2004