Background

Emergence delirium in children is a complex post-anaesthetic state characterised by disturbances in attention and cognition. This potential unpleasant and distressed condition has been described to characterise behaviours like loss of eye contact, unawareness of surroundings, and unpurposefulness. Children might harm themselves and additional nursing care might be required. The incidence range widely across studies from about 7% to 80%, a variability attributed to several factors, such as measurement methods and anaesthetic agents used. However, associated risk factors are not clearly established.  Being able to identify children at risk for emergence delirium   is crucial. The behaviour might not just be problematic solely in the immediate post-anaesthetic period, as it   has been linked to long-term problems such as nightmares and separation anxiety, although the findings are not entirely conclusive. The only validated tool for identifying emergence delirium in children, the Pediatric Anesthesia Emergence Delirium scale, has been questioned as to whether all its items are specific to delirium, as some may be more aligned with pain. Regarding parents' and children's experiences of emergence delirium, there is a lack of research. The overall aim of this thesis was to evaluate the Pediatric Anesthesia Emergence Delirium scale, to explore the incidence of emergence delirium, to evaluate associated factors to emergence delirium and to describe parents’ experiences of their child's emergence delirium behaviour as well as the child's experiences of having been in this condition.

Methods

Initially, children under seven years of age, anaesthetised for any type of surgery or diagnostic procedure, were consecutively enrolled. The children’s behaviours were observed and assessed upon emerging from anaesthesia by using the five item Pediatric Anesthesia Emergence Delirium scale. Parents of children identified as exhibiting emergence delirium were subsequently invited to participate in a later interview, during which they were asked to describe their experiences of the emergence delirium episode. Children were also invited. Thematic analysis was applied.

Furthermore, a second recruitment process was conducted, in which children under seven years of age, undergoing ear, nose and throat surgery, were consecutively enrolled. Data was collected throughout the perioperative period, encompassing the children's behavioural characteristics, their distractibility during needle cannulation or mask induction, anaesthetic management, and levels of emergence delirium and postoperative pain.

Results

A total of 122 children were included in the initial study. The Pediatric Anesthesia Emergence Delirium scale was evaluated, and the exploratory factor analysis clearly revealed a one-factor solution, accounting for 82% of the total variance. Interrater reliability was established for both individual items and the total score.

During the primary analysis of data from the second study population, difficulties arose in distinguishing emergence delirium from pain due to similarities between the items in the Pediatric Anesthesia Emergence Delirium scale and the Face, Legs, Activity, Cry, and Consolability scale, the instrument used to assess pain. Therefore, further analyses were conducted of the Pediatric Anesthesia Emergence Delirium scale, by using statistical methods appropriate for ordinal data. Data from 350 enrolled children was applied. A confirmatory factor analysis was performed: a one-factor model, encompassing the original five item scale was compared to a two-factor model, encompassing proposed delirium-specific behaviours (first three items) versus proposed delirium-nonspecific behaviours (last two items). The findings demonstrated a clear advantage for the two-factor model, which exhibited excellent model fit. The one-factor model was identified as significant, indicating a lack of fit to the data. The ordinal alpha of 0.98 supported the internal consistency reliability of the delirium-specific behaviours. There was a strong correlation between delirium-nonspecific behaviours and the Face, Legs, Cry, and Consolability scale, supporting convergent validity. The delirium-specific items; i.e., the revised Pediatric Anesthesia Emergence Delirium scale, were therefore suggested as a more valid and reliable measure of emergence delirium than the original five item scale. The receiver-operating characteristic curve analyses suggested two tentative cutoff scores for the revised scale: ≥ 6 and ≥ 8.

Further analyses of data from the second study population were then feasible. Based on the revised Pediatric Anesthesia Emergence Delirium scale, the incidence of emergence delirium was 27.9 %. In the multiple linear regression analyses, four factors were significantly associated with emergence delirium; younger age, difficulty being distracted, shorter sleep time in the recovery unit, and higher pain levels. Significantly higher emergence delirium scores were found in children undergoing mask induction compared to those with intravenous induction. The child’s behaviour characteristics were not associated with emergence delirium.

Sixteen parents and one child were interviewed in the qualitative study. When reuniting with their child exhibiting emergence delirium, parents felt as they were encountering a comprehensive scenario. They experienced fear and insecurity and had feelings of powerlessness and guilt. However, information and previous experiences offered relief as well as being seen by the healthcare staff, which gave hope and energy.  The child remembered being wild and out of control.

Conclusion

Interrater reliability was established for the original Pediatric Anesthesia Emergence Delirium scale. Furthermore, the revised Pediatric Anesthesia Emergence Delirium scale was reported as a more valid and reliable measure of emergence delirium than the original five item scale; internal consistency reliability and convergent validity were supported. Based on the revised Pediatric Anesthesia Emergence Delirium scale, about one-fourth of the children were defined emergence delirium. Younger age, difficulty being distracted, shorter sleep time in the recovery unit, and higher pain levels were significantly associated with this condition. Mask induction resulted in significantly higher emergence delirium scores then intravenous induction. Parents felt as they were encountering a comprehensive scenario, when reuniting with their child exhibiting emergence delirium. They experienced fear and insecurity and had feelings of powerlessness and guilt. However, information and being seen by the healthcare staff offered relief.