Moderate sedation and deep sedation are well-established techniques in many developed countries, and several guidelines have been published. However, the techniques have received attention in China only in recent years. Our survey shows that most tertiary children’s hospitals and tertiary maternity and children hospitals in China provide moderate and deep sedation for non-invasive procedures. The hospitals that provide sedation on a larger scale tend to have better facilities and staff composition. Pulse oximetry is monitored in more than 65.5% of hospitals during sedation procedures, but only a few hospitals (about 15%) perform capnography monitoring. Chloral hydrate is still the most commonly chosen sedative agent; however, the use of chloral hydrate tends to decline and the use of dexmedetomidine and propofol tend to increase gradually with patient age. Propofol (15.5%) and inhaled anaesthetics (15.5%) are the most commonly used rescue sedatives. Our study shows that there are no mandatory training requirements for the staff providing sedation in many hospitals.
Most hospitals in China do not have dedicated sedation rooms or post-sedation recovery rooms. Although it is not specifically mentioned in the guidelines, sedation rooms and post-sedation recovery rooms are necessary so that sedation providers can properly monitor and manage paediatric patients. It is alarming that sedation rooms and post-sedation recovery rooms are established in only 24.1% and 32.8% hospitals, respectively. Considering the potential risks of moderate and deep sedation (e.g. vomiting, aspiration, hypotension, and apnoea), we believe that standard facilities should be available wherever sedation procedures are provided to ensure the safety of paediatric patients.
According to the National Institute for Health and Care Excellence (NICE) guidelines, staff involved in moderate and deep sedation, including physicians and nurses, should have knowledge of and competency in sedation drug pharmacology, assessment of children, monitoring, recovery care, and management of complications11. Moderate sedation and deep sedation require teamwork; although there is no specific requirement for the number of team members, all guidelines emphasize that sedation providers must be competent in life-support skills. The NICE guidelines suggest all providers of moderate and deep sedation should be trained in basic life-support and at least one team member present for the duration of deep sedation should be competent in advanced life-support11. The AAP and AAPD also suggest at least one team member trained in advanced paediatric life support and skilled in airway management and cardiopulmonary resuscitation be present during deep sedation6, 7. It should be noted that life-support skills are emphasized in all sedation guidelines, but no guideline has addressed the question of who should be responsible for sedation. There is no doubt that life-support skills are the specialties of anaesthesiologists; they are the first choice for sedation management. However, the number of anaesthesiologists is limited and they can hardly fulfil all the needs. Our study reveals that other sedation providers such as nurses and radiologists are also involved. Although accumulating evidences show that procedural sedations can be safely and effectively performed in adult patients classified as ASA I-II by non-anaesthesiologists 12-15, whether this can also be extended to adult patients classified as ASA III or higher is still inclusive. Recent guideline for non-anesthesiologist administration of propofol for gastrointestinal endoscopy from European society of gastrointestinal endoscopy suggests primary involvement of an anesthesiologist in patients of ASA class ≥3, with a Mallampati’s class ≥3 or other conditions that put them at risk of airway obstruction (e.g. pharyngolaryngeal tumors), in patients who chronically receive significant amounts of narcotic analgesics, or in cases where a long-lasting procedure is anticipated16. Similar to the sedation studies in adult patients, whether procedural sedation can be safely performed in paediatric patients with ASA III or higher by non-anaesthesiologists still needs further in-depth exploration17-19. Sedation providers must be competent in life-support skills. If the sedation provider is not competent in life-support skills, someone who is must be present for the duration of sedation. In view of this point, we think that instead of asking “Who should manage sedation?” we should ask, “What training should sedation providers receive?” According to the guidelines mentioned above, training should include sedation drug pharmacology, assessment of children, monitoring procedures, recovery care, and management of complications. Life-support courses should also be included. PBLS or PALS certification is certainly advantageous; however, PBLS or PALS certification does not mean a provider has been trained to manage sedation. At present, there is no standard training course for sedation providers. Specific credentialing and training strategies should be considered in the development of a national guideline. Effective sedation education and training, especially for non-anaesthesiologists, is essential to improve patient safety during moderate and deep sedation. High-fidelity simulation might be an ideal solution; it has been shown to improve skills, knowledge, self-confidence, awareness of emergency, crisis resource management, and teamwork. However, as far as we know, minimal content has been developed for sedation training. Moreover, high-fidelity simulation is costly and requires expertise for the operation of the equipment, which has restricted its popularization.
The NICE guidelines suggest that fasting is not needed for moderate sedation, during which the child maintains verbal contact with the sedation provider. For children who cannot maintain verbal contact (i.e. moderate-to-deep sedation) the 2-4-6 fasting rule should apply11. However, it is difficult to accurately control the depth of sedation in clinical practice due to differences in pharmacodynamics and pharmacokinetics. The necessity of pre-sedation fasting has been debated. Many published studies have reported no association between fasting duration and adverse events such as vomiting and pulmonary aspiration20-22. Furthermore, the risk of hypovolemia and hypoglycaemia caused by prolonged fasting cannot be ignored in critically illed children. In these cases, a shorter fasting time should be considered. In our institution, milk is allowed 2 hours before procedural sedation for children with congenital heart disease. Adverse events such as vomiting and aspiration are extremely rare. Surely more experienced staff is needed to ensure the safety of these children, and rescue equipment must always be available, but we believe that the risks are controllable.
Insufficient monitoring is another problem of moderate and deep sedation in China. Pulse oximetry, electrocardiography, and non-invasive blood pressure and end-tidal carbon dioxide monitoring during moderate and deep sedation is performed in 65.5%, 41.4%, 27.6%, and 13.8% of hospitals during magnetic procedures, respectively, and in 77.6%, 44.8%, 34.5%, and 15.5% of hospitals during nonmagnetic procedures, respectively. This reveals that the adoption of such monitoring procedures occurs less frequently than previously reported23. It is believed that end-tidal carbon dioxide monitoring is more sensitive than pulse oximetry for respiratory events, which can lead to hypoxemia during procedures24,25; the latest ASA guidelines also state that continuous monitoring of ventilatory function with capnography should supplement standard monitoring9.
The choice of sedatives is another interesting topic. Chloral hydrate is the most commonly used first-choice sedative in our study because of its relatively benign clinical profile and low cost. Other sedatives intended for general anaesthesia (propofol and ketamine) and even inhaled anaesthetics are used as the first choice in some hospitals. However, 10 years ago, chloral hydrate may have been one of the only options in China (another option may have been barbiturates) for paediatric moderate and deep sedation. There are two reasons for this. First, anaesthesiologists have gradually taken over paediatric moderate and deep sedation practice in China only in recent years. Sedatives intended for general anaesthesia and inhaled anaesthetics are not considered alternatives if anaesthesiologists are not present. Second, at that time, dexmedetomidine was not yet approved for paediatric clinical use in China. Now, dexmedetomidine is widely used as an ideal sedative in China. It can be easily administrated intranasally, and children tolerate it well. Miller et al. reported that 2 and 3 μg·kg-1 of intranasal dexmedetomidine were as effective for transthoracic echocardiography sedation as oral chloral hydrate, with similar sedation onset and recovery times in infants and toddlers26. Dexmedetomidine can also be used as a rescue sedative. After failed chloral hydrate sedation, the rescue success rate of dexmedetomidine increases in a dose-dependent manner27, and the effective dose 50 of dexmedetomidine for rescue increases with age in those younger than 3 years28. Compared with chloral hydrate, intranasal dexmedetomidine has a higher rescue success rate than a second dose of chloral hydrate after failed chloral hydrate sedation29. It should be noted that all references cited in this paragraph are the results of clinical trials for Chinese children. We believe that dexmedetomidine will be more popular as a safe, effective, and well-tolerated sedative in China in the future.
Ketamine is another widely used sedation agent; it can be used safely and effectively for paediatric procedural sedation30, especially for invasive procedures, because of its analgesic properties31-33. Recent studies have reported that ketamine can be used in combination with other sedatives for better sedation quality and fewer adverse events34-36. Ketamine seems to be an ideal sedative in most cases; however, only a few providers reported using ketamine as a sedative in our study, probably because ketamine is strictly regulated and difficult to acquire in China.
Although all tertiary children’s hospitals and tertiary maternity and children hospitals registered with the National Health Commission of the People’s Republic of China were asked to participate, 17 hospitals could not be contacted. Some limitations also exist in the study design; only one physician from each hospital was invited to join the survey. Prescribing habits may vary among physicians, other providers (e.g. emergency department doctors) may be involved, and even fasting and monitoring practices may not be strictly enforced after hours. Responses from one physician may not accurately represent all providers within the institution. Additionally, procedural sedation practices outside of the hospital setting were not captured in our study. All of the limitations mentioned above could results in bias. However, the hospitals included in our study did represent the tertiary centres providing paediatric service in different provinces across China, and we believe that the study still sheds light on the state of sedation practice in China.