The authors reply.

Pediatric Critical Care Medicine www.pccmjournal. org 87 The authors reply: We welcome the opportunity to respond to the comments from Drs. Traube and Silver (1) about our systematic review (2), recently published in Pediatric Critical Care Medicine, on the lack of specificity in pediatric assessment tools when differentiating delirium from iatrogenic withdrawal syndrome (IWS) from sedatives. We find their comments erudite and entirely accurate, and we have no hesitation in agreeing with their clinical approach to individual patients under their expert care. Further, we reiterate the idea they espouse: first screen patients for possible “delirium” with one of the instruments available, then personally evaluate them en face so as to make a clinical diagnosis and, finally, to determine a management plan. No one could argue against the importance of such a sequence (i.e., screen-assess/think-diagnose-manage) in the PICU. Our contention, however, is that a positive result in the screening for potential delirium using various instruments now appears to have become the recommended diagnostic test for delirium (3), rather than the subsequent clinical assessment as described by Drs. Traube and Silver (1) in their correspondence. Our literature review addresses this point in particular—the message is that if one is solely using the screening instruments to determine epidemiology in the PICU, then there is the risk of underor overestimation in case prevalence because of the overlapping “diagnostic” domains with other entities such as sedative/hypnotic IWS (2). (We have outlined sensitivity and specificity of “diagnosis” against en face psychiatric assessment in our article (2), and the reader can review the findings by age). This lack of precision (i.e., screening as the “diagnosis” vs en face assessment as the diagnosis of delirium), along with inherent overlapping domains in the screening instruments for delirium and IWS, means that there is the potential for circularity when the screening instrument is then used to identify, for example, sedative/hypnotic agents as a potential modifiable factor (4, 5). What is being modified? Perhaps it does not matter, just as long as it is. However, treatment for straightforward IWS without delirium would involve replacing some of the agent(s) previously withdrawn, while these agents might be avoided or minimized in delirium. We believe that epidemiology has a role in moving our field forward, and hence, we contributed the review to “Pediatric Critical Care Medicine,” not to be contrary, but with the aim of focusing thought on an issue that Drs. Traube and Silver (1) have also recognized (6). Therefore, our conclusion remains the same as we wrote in our report (2): “We have drawn attention to the overlap between the symptom/sign scales used for assessing IWS, delirium and anticholinergic toxidrome not to comment on individual patient care, but rather to point out issues that need to be addressed in more widespread epidemiologic research of these symptom syndromes. Indiscriminate implementation and interpretation of any of these scales may result in misdiagnosis. Although each of these scoring systems may serve as useful tools, we suggest interpretation in the full clinical context, and interventions administered on a case-by-case basis. ” If we are to learn from epidemiology in this particular area, then we still need robust case definitions that can be used efficiently in large populations. 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. The authors have disclosed that they do not have any potential conflicts of interest.