Hallucinations and delusions in pediatric ICUs and PTSD

Nearly one in three children admitted to pediatric intensive care will experience delusions or hallucinations, which put them at higher risk for post-traumatic stress symptoms, according to a new study of children's experiences in a pediatric intensive care unit (PICU).

The study is believed to be the largest ever conducted on children's memories of PICU.

The results confirmed the clinical experience of the study's first author, Gillian Colville, BSc, MPhil, a clinical psychologist, and underscore the need to look at this issue more closely. "I have worked for 16 years in pediatric intensive care and have seen a considerable number of children in distress, but have found that there is very little in the literature about children's experiences," said Ms. Colville.

To determine whether she was witnessing a unique population of children, or if hallucinations and delusional memories were an overlooked but common experience for children in the PICU, Colville and her collaborators recruited children over the age of seven who were discharged from the 21-bed PICU at Great Ormond Street Children's Hospital in London, over the course of 18 months. Each child's medical condition and treatment was noted and they were given a psychological interview three months after discharge to screen them for post-traumatic stress symptoms in relation to their memories.

Of the 102 children who completed interviews, two in three recalled something factual about their stay at the PICU — and half of these had only fragmentary, single memories, mostly images of family members. But one in three children reported delusional memories of their stay in PICU, including hallucinations. It was these children who reported delusional memories that had a significantly higher score on the post-traumatic stress screening test than others.

"These findings are interesting because it has been assumed that the actual experiences in the PICU would be more likely to lead to post-traumatic stress symptoms following discharge," said Ms. Colville. "However, our results indicate that post-traumatic stress symptoms are associated with delusional memories rather than factual ones. The hallucinations children reported were overwhelmingly disturbing and frightening, similar to those reported by adult intensive care patients and heroin addicts going through withdrawal."

The findings have important clinical implications, as the timing of the hallucinations appeared to coincide with the period during which they were being weaned off the sedatives commonly prescribed in PICU (benzodiazepines and opiates) and children were five times as likely to report having had delusions or hallucinations if they had been prescribed opiates and benzodiazepines for more than two days.

The authors do not suggest that the drugs be discontinued, but that they do warrant further study. Additional research could establish whether alternative types of sedation or the introduction of drug holidays might produce fewer traumatic delusional memories. The authors also suggest altering the physical environment and providing psychological orientation cues for children in the PICU, such as demarcating day and night, to help reduce these symptoms.

"But above all, medical professionals and families should be made aware of the possibility that children may have these disturbing hallucinatory experiences, and greater efforts should be made to monitor their psychological adjustment after PICU," said Ms. Colville.

---

Colville G, Kerry S, Pierce C. Children's Factual and Delusional Memories of Intensive Care. Am. J. Respir. Crit. Care Med. 2008 May 1;177:976-982   [Abstract]