Inter-observer reliability of ten tests used for predicting difficult tracheal intubation.
OBJECTIVE
To determine inter-observer reliability of ten preoperative airway assessment tests used for predicting difficult tracheal intubation.


METHODS
We prospectively assessed 59 patients undergoing elective surgery requiring tracheal intubation at a large metropolitan teaching hospital. Two experienced observers independently conducted the airway assessment tests on the same group of patients. Inter-observer reliability was examined using Kappa (K) and intraclass correlation coefficient (ICC).


RESULTS
Two tests--mouth opening (ICC = 0.93) and chin protrusion (ICC = 0.89)--had excellent inter-observer reliability. Seven tests--thyromental distance (ICC - 0.74), subluxation (K = 0.66), atlanto-occipital extension distance (ICC = 0.67) and angle (K = 0.66), profile classification (K = 0.58), ramus length (ICC = 0.53), oropharyngeal best view (K = 0.49)--were moderately reliable. One test--Mallampati technique of assessing oropharyngeal view (K = 0.31)--had poor reliability.


CONCLUSIONS
Many of the preoperative airway tests have only moderate inter-observer reliability. This may provide some insight into why previous research has failed to show that the tests accurately predict difficult tracheal intubation.
Karkouti
K
K
Department of Anaesthesia, St. Michael's Hospital, Toronto, Ontario, Canada.
Rose
D K
DK
Ferris
L E
LE
Wigglesworth
D F
DF
Meisami-Fard
T
T
Lee
H
H
D001269:Atlanto-Occipital Joint / Q000033:anatomy & histology; D015982:Bias; D002680:Chin / Q000033:anatomy & histology; D017558:Elective Surgical Procedures; D005145:Face; D005544:Forecasting; D006801:Humans; D007442:Intubation, Intratracheal / Q000706:statistics & numerical data; D008334:Mandible / Q000033:anatomy & histology / Q000502:physiology; D009055:Mouth / Q000033:anatomy & histology; D009068:Movement; D009333:Neck / Q000033:anatomy & histology; D015588:Observer Variation; D009960:Oropharynx / Q000033:anatomy & histology; D011446:Prospective Studies; D015203:Reproducibility of Results; D013961:Thyroid Gland