OBJECTIVETo analyze the risk factors for difficult airway in laryngoscopy and mask ventilation.

METHODSA total of 300 patients receiving general anesthesia with tracheal intubation were examined preoperatively for height, thyromental and sternomental distance (TMD), range of neck movement, inter-incisor distance, and modified Mallampati class. Intubation Difficult Score was used to identify a difficult laryngoscopy. Difficult airway was defined as either difficult laryngoscopy or difficult mask ventilation. The association between the airway characteristics and difficult airway was analyzed by logistic regression analysis, and the cut-off values for the height-to-TMD ratio was determined by the ROC curve.

RESULTS AND CONCLUSIONEight airway characteristics were identified to contribute to a difficult airway, including (OR [95%CI]) the height-to-TMD ratio (3.58[1.95-8.46]), modified Mallampati class (3.34 [1.82-7.14]), BMI (3.07 [1.64-6.69]), history of a previous difficult airway (2.79 [1.28-5.25]), a thick neck (2.15 [1.04-4.37]), range of neck movement (1.98 [0.96-3.89]), sternomental and angulus mandibulae distance (1.46 [0.67-3.04]), and inter-incisor distance (1.01 [0.49-2.54]). The optimal cut-off value for the height-to-TMD ratio was 22.8 for predicting a difficult airway.

Anesthesia, General ; Body Height ; Humans ; Intubation, Intratracheal ; Laryngoscopy ; Logistic Models ; Neck ; anatomy & histology ; ROC Curve ; Risk Factors ; Trachea ; anatomy & histology

The precise three-dimensional (3-D) segmentation of airway from CT image is essential for the image-guided therapy, which helps avoid a serious airway injury. We proposed a new segmentation algorithm for the calculation. Firstly, region growing method was employed to segment the main bronchioles (rough segmentation). And then region growing driven by morphology dilation was used to expand the airway region, where centerline of airway tree was extracted. Terminal bronchia (fine segmentation) were segmented along the centerline. Ultimately, rough and fine segmentation results are combined by a logical OR as final airway tree. Quantitative comparisons with 6 sets of manual segmentation results showed that the algorithm could be used to segment up to 9 bronchia, and the average branch sensitivity of 6th was 63.5%, meeting the requirement of airway tree in the image-guided therapy.
Algorithms ; Bronchi ; anatomy & histology ; Humans ; Imaging, Three-Dimensional ; Radiographic Image Enhancement ; methods ; Radiotherapy, Image-Guided ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed ; methods ; Trachea ; anatomy & histology ; diagnostic imaging

Long-segment tracheal stenosis in infants and small children is difficult to manage and can be life-threatening. A retrospective review of 12 patients who underwent surgery for congenital tracheal stenosis between 1996 and 2004 was conducted. The patients' median age was 3.6 months. All patients had diffuse tracheal stenosis involving 40-61% (median, 50%) of the length of the trachea, which was suspected to be associated with complete tracheal ring. Five patients had proximal bronchial stenosis also. Ten patients had associated cardiac anomalies. Three different techniques were performed; pericardial patch tracheoplasty (n=4), tracheal autograft tracheoplasty (n=6), and slide tracheoplasty (n=2). After pericardial tracheoplasty, there were 2 early and 2 late deaths. All patients survived after autograft and slide tracheoplasty except one who died of pneumonia one year after the autograft tracheoplasty. The duration of ventilator support was 6-40 days after autograft and 6-7 days after slide tracheoplasty. The duration of hospital stay was 13-266 days after autograft and 19-21 days after slide tracheoplasty. Repeated bronchoscopic examinations were required after pericardial and autograft tracheoplasty. These data demonstrate that pericardial patch tracheoplasty show poor results, whereas autograft or slide tracheoplasty gives excellent short- and long-term results.
Body Weight ; Female ; Follow-Up Studies ; Humans ; Infant ; Infant, Newborn ; Length of Stay ; Male ; Pulmonary Artery/pathology ; Respiratory System Abnormalities/surgery ; Thoracic Surgical Procedures ; Trachea/anatomy & histology ; Tracheal Stenosis/*congenital/*surgery ; Treatment Outcome