The inclusion criteria for this study were children who underwent EEG in our hospital who received 2.5 μg·kg− 1 of intranasal DEX. Children were excluded when they met any of the following criteria: (1) A history of allergy to DEX, (2) difficult airway, (3) anatomical structural deformity of the nasal cavity, (4) severe liver or renal insufficiency and (5) severe bradycardia or atrioventricular block above II degree type 2.
Our standard sedation procedure was as follows. Children needed to fast for at least 1 h before sedation. An anaesthesiologist evaluated the patient’s general condition, history of the present illness, previous medical history, surgical history, allergy history and sedative history. Then, the anaesthesiologist created an appropriate sedative plan, and an informed consent form was signed. The child was placed in a supine position and attended by a guardian, and a nurse administered a nasal drip of 2.5 μg·kg
− 1 DEX to the child. All the children remained lying flat for 1–2 min after the medicine was administered while we gently massaged the alae of the nose of the children to facilitate DEX absorption by the nasal mucosa. We used the Modified Observer Assessment of Alertness/Sedation Scale (MOAA/S) [
14] (Table
1) to evaluate the children’s sedation state. Successful sedation was defined as an MOAA/S score less than or equal to 3 within 30 mins after the first dose of DEX. If the MOAA/S score was greater than 3 within 30 min after the first dose of DEX, an additional 1 μg·kg
− 1 intranasal DEX was given as a “rescue” dose. If the EEG could still not be completed, inhaled sevoflurane were administered to allow the examination to be completed, which we defined as failed sedation. After drug administration, the anaesthesiologist not only assessed the child’s sedation level but also recorded heart rate (HR), pulse oxygen saturation (SpO
2), and the occurrence of adverse events, which referred to postoperative nausea and vomiting (PONV), bradycardia, SpO
2 reduction, etc. The EEG was performed after successful sedation, while the attending physician used a portable monitor to track the patient’s HR and SpO
2. We defined the onset time of sedation as the time from drug administration to successful sedation. Recovery time was defined as the time from successful sedation to recovery. After the examination, the children were sent back to the sedation recovery room for further observation. Patients were discharged upon attaining a Modified Aldrete score (MAS) [
15] (Table
2) of 9 or upon reaching the following states: (1) stable cardiovascular function and unobstructed respiratory tract; (2) awakened easily, with protective airway reflexes intact; (3) ability to communicate with others (age-appropriate assessment); (4) able to sit up unassisted (age-appropriate assessment); (5) for very small children or children with disabilities who were unable to exhibit the usual expected responses, a return to pre-sedation response levels or to as close to normal as possible; and (6) adequate hydration status.
Table 1Modified Observer’s Assessment of Alertness/Sedation Scale
Agitated | 6 |
Responds readily to name spoken in normal tone | 5 |
Lethargic response to name spoken in normal tone | 4 |
Responds only after name is called loudly and repeatedly | 3 |
Responds only after mild prodding or shaking | 2 |
Does not respond to mild prodding or shaking | 1 |
Does not respond to a deep stimulus | 0 |
Table 2Modified Aldrete score
Activity |
Move 4 extremities voluntarily or on command | 2 |
Move 2 extremities voluntarily or on command | 1 |
Unable to move extremities voluntarily or on command | 0 |
Respiration |
Able to breathe deeply, cough, and/or cry | 2 |
Dyspnoea or limited breathing | 1 |
Apnoeic | 0 |
Circulation |
Blood pressure ± 20 mmHg of preanaesthetic value | 2 |
Blood pressure ± 21 to 49 mmHg of preanaesthetic value | 1 |
Blood pressure ± 50 mmHg of preanaesthetic value | 0 |
Consciousness |
Fully awake | 2 |
Arousable on calling | 1 |
Unresponsive | 0 |
Oxygen saturation |
Able to maintain oxygen saturation > 92% on room air | 2 |
Needs oxygen inhalation to maintain oxygen saturation > 90% | 1 |
Oxygen saturation < 90% even with oxygen supplementation | 0 |