[The efficacy of using cephalometrics to predict difficult intubation of patients with obstructive sleep apnea hypopnea syndrome].

PURPOSE

To investigate the difference of radiological measurements between difficult-to-intubate obstructive sleep apnea hypopnea syndrome(OSAHS) patients and easily-to-intubate ones, and explore the feasibility of cephalometry in predicting difficult intubation.

METHODS

Thirty male OSAS patients who received general anesthesia underwent cephalometrics before operation. Mallampati grade was used to evaluate the intubating condition of all patients before endotracheal intubation. After awake intubation and general anaesthesia, Cormack and Lehane laryngoscope grade was used to confirm the difficult-to-intubate patients and easily-to-intubate ones. The difficult-to-intubate patients were set into group I (n=13), the easily-to-intubate patients were set into group II (n=17). X-ray cephalometric radiographs were scanned into computer, 22 cephalometric parameters were measured with CASSOS 2001 cephalometric software. The measured items included hard tissue of maxilla and mandible, soft tissue of tongue and soft palate, airway space, hyoid and other parameters. SPSS13.0 software package was used for independent sample t test.

RESULTS

The interface length of tongue and soft palate (CL), the tongue length (TGL) and the hyoid-mental distance (H-MP) were significantly different between the two groups (P<0.05). In difficult-to-intubate OSAS patients, the tongue area (TA) was larger, the soft palate length (PNS-U) was longer, the Atlanto-occipital gap (AOG) was shorter, but the difference was not significant.

CONCLUTIONS

X-ray cephalometric indicators closest associated with difficult intubation in OSAHS patients are CL, TGL and H-MP, which are instructive for predicting difficult intubation.