Identify Delirium, Then Investigate for Underlying Etiology
Delirium screening is designed to identify delirium, rather than “differentiate” delirium from IWS. Once delirium has been diagnosed, the next step should be determining why the child is delirious. If the delirium is a function of IWS, treatment would be judicious replacement of opiate to treat the abstinence. If the delirium is a result of anticholinergic exposure, appropriate therapy would be reducing the anticholinergic burden. Delirium can also be the result of a new underlying disease process, such as an occult urinary tract infection. In that case, treatment for the delirium would involve initiation of appropriate antibiotics, in addition to managing the behavioral symptoms (2). We strongly disagree with the authors’ statement that a diagnosis of delirium should “prompt consideration of treatment with an antipsychotic medication, and avoidance of additional benzodiazepines” (1). A diagnosis of delirium should prompt an investigation into its underlying trigger(s), rather than an automatic pharmacologic intervention.
It is important to note that the majority of delirium in the PICU is generally of early onset, with most children initially diagnosed within the first 3 days (3–5). This is likely before the initiation of a sedative wean that might precipitate IWS. In the clinical vignette, the authors describe a child with acute respiratory failure who requires high-dose sedation (1). We hypothesize that perhaps this child developed an agitated delirium early on, which was managed with escalating sedatives (many with anticholinergic effects) rather than appropriate minimization of delirium triggers. This increased sedative exposure, and then it increased the child’s subsequent risk for IWS and anticholinergic toxicity. Once sedation was tapered, the delirium again emerged, only this time exacerbated by IWS.
A holistic approach to minimizing sedation may address many of these problems. Specifically, an analgosedation approach, as advocated by Society of Critical Care Medicine for management of critically ill adults, may be well suited for the PICU. With an analgesic first approach, and optimal pain control, we can minimize sedation. With less sedatives on board, we can better recognize pain and more effectively mobilize the patient. Less sedation and more mobilization will likely lead to less delirium and less IWS (2).
In summary, with universal delirium screening as standard of care in the PICU, delirium can be detected early when it is most amenable to treatment. With close attention to clinical context, the underlying etiology of delirium (including IWS and anticholinergic toxidrome) can then be thoughtfully addressed. We thank the authors for this systematic literature review on an important and timely topic in pediatric critical care medicine.