Table 4. Contraindications for sedation.

Conditions in which airway management is likely to be difficult	Abnormal airway (including large tonsils and anatomical abnormalities of upper or lower airway)
	History of sleep apnoea
	Nasal blockage
Disorders with a high risk of respiratory failure	Neuromuscular disease
	Decreased consciousness level
	Respiratory failure
	Cardiac failure
	Lobar emphysema
	Pulmonary cysts of bullae
	Severe pulmonary hypertension
Abnormality with the increased likelihood of pulmonary aspiration	Raised intracranial pressure
	Bowel obstruction
	Pneumoperitoneum