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

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: 10.1111/j.1553-2712.2010.00706.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 attempt intubation

Tracheal Oesophageal Mean Tracheal Intubation Time

Pre training 19% 17% 97 seconds

Post training 36% 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: 10.1111/j.1553-2712.2010.00706.x

2) Difficult airway society guidelines 2004