Sedation of children in the intensive care unit: what’s new in the field?
Background. The purpose of sedation is to reduce anxiety, create amnesia, reduce motor activity when performing invasive procedures, and provide the synchronization with the respirator. The ideal sedative drug should be characterized by minimal toxicity and minimal depressant effects on the cardiovascular system, the possibility of rapid awakening, the absence of withdrawal syndrome.
Objective. To describe the sedation of children in the intensive care unit.
Materials and methods. Analysis of literature sources on this topic.
Results and discussion. A meta-analysis of 25 studies found that sedation is often suboptimal and rarely regularly evaluated. Excessive sedation can increase the duration of hospitalization, cause tolerance and withdrawal syndrome (Nienke J. Vet et al., 2013). In turn, insufficient sedation increases distress and the frequency of complications, including infectious ones. Frequent problems of sedation also include the choice of suboptimal drug, prolonged infusion, limited use of propofol and dexmedetomidine, lack of routine practice of earplugs and face masks, insufficient frequency of delirium assessment. In a significant proportion of cases, benzodiazepines, primarily midazolam, are used for sedation. In hepatic insufficiency, lorazepam is preferred. Disadvantages of benzodiazepines are respiratory depression, vasoplegia, cardiopression, withdrawal syndrome. Midazolam is often combined with fentanyl or morphine, however, there is little evidence of such a combination. Propofol infusions can cause metabolic acidosis, hyperkalemia, hyperlipidemia, rhabdomyolysis, and even heart failure. The so-called propofol infusion syndrome develops at a dose >4 mg/kg/h in case of infusion for >48 hours. Analysis of sedation with propofol (at a dose 0.3-6.5 g/kg/h) in 174 children aged from 2 months to 16 years revealed that 8 children exceeded the threshold level of lactate; one child died (Svensson M., Lindberg L., 2012). According to the authors of another study, propofol is safe at a dose of 1-4 mg/kg/h. Clonidine and dexmedetomidine are centrally acting α2a-agonists that exert their effects in the locus coeruleus of the brainstem. Dexmedetomidine does not cause respiratory depression and withdrawal syndrome. Children receiving dexmedetomidine required significantly less morphine than ones receiving midazolam. Dexmedetomidine has been shown to reduce the number of inadequately sedated patients (Tobias J.D. et al., 2004). The pharmacokinetics of this drug in children older than 4 years corresponds to the pharmacokinetics in adults. At a dose of 0.1-0.25 μg/kg/h dexmedetomidine reduces the need for benzodiazepines and opioids, as a monosedation at a dose 0.25 μg/kg/h it is comparable to midazolam, and at a dose of 0.5 μg/kg/h – exceeds the latter in efficiency. Meta-analysis of M. Plambech and A. Afshari (2014) found that dexmedetomidine is convenient and safe for use in children with various pathological conditions. In order to prevent complications, non-pharmacological techniques should be used (reduction of light and sound stress, formation of normal biorhythms, swaddling of young children) and switch to oral forms of necessary drugs as soon as possible.
Conclusions. 1. Frequent problems of sedation include insufficient/excessive sedation, choice of suboptimal drugs, prolonged infusion, limited use of propofol and dexmedetomidine, lack of routine practice of earplugs and face masks, insufficient frequency of delirium assessment. 2. It is necessary to form sedation protocols in children. 3. For optimal sedation, it is important to implement modern techniques and drugs, regularly assess the level of sedation and treat the underlying pathological condition.
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