1. Short trachea with 15 rings or less; high chance of accidental one lung ventilation
2. Chances of Laryngeal Stenosis... Some times an unanticipated difficulty for passing tube, may trigger edema and stridor ( one such case reported, needed emergency tracheostomy)
3. Atlanto axial instability, can cause, massive cord edema, even with moderate neck flexion ( one case suffered tetraparesis after intubation; so in clear words, explain to the relatives..,the anticipated amount of morbidity and mortality) Take LATERAL CERVICAL SPINE VIEWS IN FLEXION AND EXTENSION PREOPERATIVELY. If atlantoaxial instability is present and patient requires GA, give MANUAL IN LINE STABILIZATION/ do AWAKE FOB.
4. Restricted lung function accompanied by impending respiratory failure, is a situation, where we may be more inclined towards SAB in such patients (e.g. Pregnancy, where the uterus further compromise lung function). So regional anesthesia may be appropriate, if technically feasible.
5. Technical difficulties with SAB/EDB; epidural space located 2.5 cm from skin was reported in one case.