Table 1 Patient inclusion and exclusion criteria

Aged 3 to 65, either male or female

Mental disorder, drug dependence and drug abuse

Participants sustained 1-70% of TBSA burns or other injury requiring dressing procedure

Unconscious and unable to express pain by Changhai pain scale (VAS)

Recent worst pain (during dressing) reported to be 4 or higher (on a scale of 0 to 10)

Abdominal distension or suspected bowel obstruction, air embolism, pneumothorax, decompression sickness, epilepsy, chronic obstructive pulmonary disease and acute respiratory infection, pregnancy, severe inhalation injury; pharmaceutical or pathological pulmonary fibrosis; Maxillofacial injuries

The participants are volunteers and written consent obtained

Burns or injured area not affecting the vital signs and digital pulse oximeter monitoring

Disease involving ear, nose, larynges such as sinuses, middle ear, tympan graft