Complications from<unk>  are rare, and are those events that require intervention to correct adverse physiological responses. They include over-sedation, respiratory depression/apnoea, unconscious patient, airway obstruction, vomiting, idiosyncratic responses, delayed recovery, and failure of conscious sedation. Few absolute contraindications exist, however, "relative contraindications are important and can only be considered following a full assessment." They include: * Medical conditions that would compromise the<unk>  of the sedation medication, such as the common cold, tonsillitis, severe COPD or nasal blockage * Neuromuscular diseases affecting the respiratory system, such as multiple sclerosis and myasthenia gravis * Women in the first trimester of pregnancy * Medical or behavioural conditions that limit a patient's ability to understand the procedure * Claustrophobia or "fear of the mask".
Inhalation sedation
Sedative
Anesthesia
Sedation
Shivering
Sedoanalgesia
Nitrogen narcosis
Cardioprotection