A predictive test for difficult intubation in laryngeal microsurgery. Validation study.
BACKGROUND
In 2003 a simple test to detect difficult intubation (DI) in patients underwent laryngeal microsurgery was described. The present study was conducted to validate the test.


METHODS
Patients with laryngeal disease scheduled for laryngeal microsurgery were included. The variables evaluated were eleven parameters: Mallampati Score ≥III, thyromental distance <6.5cm, mouth opening <40mm, limitation of the temporomandibular joint, pathological dentition, arched paladet, maxillary deficiency, neck mobility <90°, body mass index, symptoms of laryngeal dysfunction, and tumour of supraglottic region. A rapid examination of the airway by an expert anaesthesiologist was carried out just before induction. DI was defined by a Cormack laryngeal view gradeiii-iv and/or if auxiliary equipment was required to achieve orotracheal intubation. A comparison of ROC curves was conducted to estimate the best predicting cut-off, as well as differences between the index described in 2003 and the rapid assessment by an expert anaesthesiologist.


RESULTS
One hundred and five patients were included in the study. The incidence of DI according to the predefined criteria was 45% (47 patients). The score at the cut-off of 5 provides a sensitivity of 89% and a specificity of 55%. The fast-evaluation by an expert anaesthesiologist obtained similar sensitivity (89%) and better specificity (81%). Area under curve (AUC) was 0.87, similar to a fast evaluation (AUC: 0.85; P=.71).


CONCLUSIONS
The index was validated at a cut-off of ≥5, being a useful and reliable test to predict DI in patients with laryngeal diseases and it is a useful tool for anaesthesiologists with conventional training.
Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital Clínic, Barcelona, España.
I
I
Belda
Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital Clínic, Barcelona, España. Electronic address: MAAYUSO@clinic.ub.es.
M A
MA
Ayuso
Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital Clínic, Barcelona, España.
X
X
Sala-Blanch
Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital Clínic, Barcelona, España.
M
M
Luis
Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital Clínic, Barcelona, España.
R
R
Bergé
D000328:Adult; D058109:Airway Management / Q000379:methods*; D000402:Airway Obstruction / Q000175:diagnosis*; D000886:Anthropometry / Q000379:methods*; D019540:Area Under Curve; D006801:Humans; D007442:Intubation, Intratracheal; D007828:Laryngoscopy; D007830:Larynx / Q000601:surgery*; D008866:Microsurgery; D010808:Physical Examination; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
Airway management; Difficult intubation; Intubación difícil; Laryngeal microsurgery; Manejo vía aérea; Microcirugía laringe