Research article
Delirium during the first evaluation of children aged five to 14 years admitted to a paediatric critical care unit

https://doi.org/10.1016/j.iccn.2017.12.010Get rights and content

Abstract

Objectives

To describe the prevalence and characteristics of delirium during the initial evaluation of critically ill patients aged 5–14 years.

Method/design

This is a cross-sectional descriptive study in a critical care unit. For six months, all patients were evaluated within the first 24–72 hours or when sedation permitted the use of the paediatric confusion assessment method for the intensive care unit (PCAM-ICU) and the Delirium Rating Scale-Revised-98 items #7 and #8 to determine motor type. We report the characteristics of PCAM-ICU delirium (at least three of the required items scored positive) and of subthreshold score cases (two positive items).

Results

Of 77 admissions, 15 (19.5%) had delirium, and 11 (14.2%) were subthreshold. A total of 53.3% of delirium and 45.5% of subthreshold cases were hypoactive. The prevalence of delirium and subthreshold PCAM-ICU was 83.3% and 16.7% in mechanically ventilated children. The most frequent combination of PCAM-ICU alterations in subthreshold cases was acute onset-fluctuation with altered alertness. The main nursing diagnoses were related to reduced cellular respiration.

Conclusions

Delirium is common in critically ill children. It is necessary to assess whether certain nursing diagnoses imply an increase in delirium. Longitudinal studies of subthreshold PCAM-ICU cases are needed to understand their importance better.

Introduction

Delirium is an acute impairment of consciousness that is characterised by alterations in three core domains: cognitive, higher-level thinking and circadian rhythm (Franco et al., 2013). The two main types are hyperactive and hypoactive. Hypoactive cases are characterised by reduced activity, decreased speed of movements and a decrease in the quantity and speed of speech. Increased movements and loss of control over movement and ambulation characterise hyperactive cases. Mixed cases feature combinations of hypoactive and hyperactive symptoms. Although delirium assessment should occur as part of the overall consciousness evaluation, delirium tends to be underdiagnosed, especially in its hypoactive form (Meagher et al., 2014).

The syndrome of delirium may be a result of one or several alterations in health. It has been more widely studied in adults than in children in intensive care, its reported prevalence is approximately 80% among adults on mechanical ventilation (Cavallazzi et al., 2012). According to the systematic review by Daoud et al. (2014), the prevalence in critically ill paediatric patients varies from 5% to 28% between studies. However, the external validity of some available studies is hampered due to differences in diagnostic methods, which include a clinical suspicion index with limited sensitivity to delirium and different index tests (such as the Paediatric Anaesthesia Emergence Delirium Scale, which has low sensitivity to hypoactive delirium), and to the high number of patients not assessed for the disorder (Daoud et al., 2014, Traube et al., 2017b). The disorder appears to be more common in children with severe illness or intellectual disability (Hatherill and Flisher, 2010).

Delirium in critically ill children increases mortality, length of hospital stay and the costs associated with care (Smeets et al., 2010, Traube et al., 2017a). Added to this is the suffering of patients and parents and additional stress for staff (Colville et al., 2009, Colville and Pierce, 2012). Reports on critically ill adults have linked hyperactive cases to safety hazards such as line removal or self-extubation (Ely et al., 2001).

A standardised diagnostic method for delirium detection in critically ill paediatric patients has yet to be routinely included in practice, which hinders the opportune diagnosis and treatment of this population (Daoud et al., 2014, Kudchadkar et al., 2014). The paediatric confusion assessment method for the intensive care unit (PCAM-ICU) is an algorithm that physicians or nurses can use to evaluate delirium in critically ill children aged ≥5 years, regardless of whether they are receiving mechanical ventilation. For a delirium diagnosis, the patient must meet at least three of four criteria (Smith et al., 2011a).

In adults, patients with a subthreshold score (i.e., meeting at least two of four criteria) on the corresponding version of the algorithm (i.e., the CAM) have been defined a priori as having subsyndromal delirium, despite the algorithm not having been validated for that. According to a systematic review about the subject, adults with a subthreshold score on the CAM or another diagnostic tool have increased morbidity and mortality in a way similar to full-syndrome delirium (Martinez Velilla and Franco, 2013). Along the same lines, the last version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) includes within the other specified delirium category an option for diagnosis of attenuated forms defined as cases in which the severity of cognitive impairment falls short of that required for the diagnosis, or in which some but not all diagnostic criteria for delirium are met (American Psychiatric Association, 2013). Unfortunately, the DSM-5 does not include operative criteria for these cases, and the chair of its task force for neurocognitive disorders acknowledges that more research is needed in the field (Blazer and van Nieuwenhuizen, 2012).

Our aim was to describe the prevalence of delirium and subthreshold PCAM-ICU cases during a cross-sectional evaluation within the first to third admission days of critically ill paediatric patients aged five–14 years, with a further description and comparison of relevant clinical and phenotypic characteristics of patients with PCAM-ICU delirium or with a subthreshold PCAM-ICU score.

Section snippets

Design and patients

This is a descriptive, observational, cross-sectional study. Fieldwork was conducted in the critical care unit of the Hospital Pablo Tobón Uribe (Medellín, Colombia), over a period of six months. The unit had 20 beds and served patients aged newborn to 14 years. Patients 15 or 16 years of age were occasionally admitted. A routine assessment of delirium was performed within the first 24–72 hours after admission to the unit for all patients aged five to 14 years. If, according to the standardised

Results

A flow diagram of cases included in this report is shown in Fig. 1. Twenty-six of the 77 patients admitted to the unit, aged from five to 14 years and consecutively assessed with the PCAM-ICU (reference patients), had delirium or a subthreshold PCAM-ICU score, for a 33.8% prevalence of delirium or subthreshold PCAM-ICU score during the initial evaluation.

Fifteen (57.7%) of the 26 patients studied had delirium, with a prevalence of 19.5%; the remaining 11 (42.3%) had subthreshold PCAM-ICU

Discussion

Approximately one-third of the patients from our critical care unit had PCAM-ICU delirium or a subthreshold score of at least two positive items. About one in five had delirium according to the PCAM-ICU. Hypoactive cases predominated, followed by hyperactive, and then by mixed cases. The patients with delirium were similar to those with subthreshold PCAM-ICU in terms of sociodemographic and health characteristics. Alterations in attention and disorganised thinking according to the PCAM-ICU

Conclusions

Delirium screening reliably identified a relatively high incidence, which correlates with other studies and highlights that paediatric patients are at significant risk. Approximately one in five children aged 5–14 years in our critical care unit had delirium during their first 24–72 h of admission, and this prevalence was approximately 80% if they were on mechanical ventilation. The frequency of PCAM-ICU subthreshold cases was also high. The hypoactive type predominated. More than half of the

Acknowledgements

To the staff of the Paediatric Critical Care Unit of the Hospital Pablo Tobón Uribe for their support during the field work.

Funding

This work was financed by the Dirección de Investigación e Innovación (CIDI) of the Universidad Pontificia Bolivariana [project: 434B-08/15-45]. The CIDI had no implication on the study design, execution, analysis or report.

Conflict of interest

The authors have no conflict of interest to declare.

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