Inter-observer agreement of spontaneous breathing trial outcome.
BACKGROUND
Spontaneous breathing trials (SBTs) are a very important test in the weaning process. The trial involves evaluation of multiple objective and subjective variables. These characteristics could lead to variability in interpreting outcomes with important clinical implications. We aimed to measure the inter-observer agreement between respiratory therapists when analyzing SBT outcomes.


METHODS
In the context of a respiratory therapist-driven weaning protocol, 2 respiratory therapists independently interpreted the subjective variables (use of accessory muscles, agitation, and diaphoresis) and the overall outcome of SBTs (success vs failure) performed in adult subjects mechanically ventilated for any duration. Raw agreements between respiratory therapists and kappa statistics were calculated.


RESULTS
One-hundred fifty-one SBTs were interpreted. The overall trial outcome raw agreement was 93.3% (95% CI 88.2-96.3) and kappa 0.63 (95% CI 0.47-0.79). Raw agreement for subjective variables ranged between 92.1% (agitation) and 99.3% (diaphoresis). The group with disagreements in overall trial outcome had higher breathing frequency, breathing-frequency-to-tidal-volume ratio, and systolic blood pressure prior to the trial.


CONCLUSIONS
Within a respiratory therapist-driven weaning protocol, we found a near 90% inter-observer agreement in the interpretation of SBT outcomes. Our findings illustrate the complexity of interpreting fluctuating subjective and objective variables and their integration into one result: SBT success versus failure. Refining the definitions of variables and their limits for failure along with education might reduce this variability.
Division of Pulmonary and Critical Care Medicine juan.figueroa@ttuhsc.edu.
Juan B
JB
Figueroa-Casas
Department of Anesthesia, Paul L Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas.
Afshin
A
Broukhim
Department of Respiratory Care, University Medical Center of El Paso, El Paso, Texas.
Adrian
A
Vargas
Department of Respiratory Care, University Medical Center of El Paso, El Paso, Texas.
Linda
L
Milam
Department of Respiratory Care, University Medical Center of El Paso, El Paso, Texas.
Ricardo
R
Montoya
D000328:Adult; D000368:Aged; D060666:Airway Extubation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011595:Psychomotor Agitation; D012119:Respiration; D012132:Respiratory Muscles / Q000502:physiology; D012138:Respiratory Therapy; D013546:Sweating; D015300:Ventilator Weaning
airway extubation; inter-observer variability; mechanical ventilators; ventilator weaning