Psychological function and biological stress markers in children following admission to intensive care

Resumen

Background: High rates of emotional and behavioural symptoms have been documented in children in the months following a critical illness requiring admission to a paediatric intensive care unit (PICU). While psychological and family factors have been well studied, there is a lack of information about the role of biological factors related to critical illness and/or to the admission to the PICU per se. In addition, little is known of the neuroendocrine correlates of these psychiatric sequelae. Objectives: To evaluate the risk of suffering psychiatric sequelae in critical illness survivors aged 5-16 years, 3-6 months after discharge from a PICU and to examine associations with critical illness and PICU admission characteristics. We also intended to investigate the regulation of the main biological stress response systems (hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenomedullary (SAM) systems) following critical illnesses and to explore associations with psychiatric sequelae. Hypotheses: 1) PICU survivors will present a higher risk of suffering a psychiatric disorder than community controls, 3-6 months after discharge. 2) The risk will be higher in the subgroup of PICU children that suffered a meningoencephalitis. 3) There are significant associations between the risk of psychiatric sequelae and features of the critical illness and/or the PICU admission. 4) The ability to regulate the basal function of the HPA and SAM systems will be altered in children that have survived a critical illness. 5) There will be associations between the risk of suffering a psychiatric disorder and the biological stress markers. Method: This is a case control study. 69 PICU patients were consecutively recruited at St. Mary¿s and Great Ormond Street Hospitals and compared to 83 community controls. PICU patients were allocated to one of these subgroups: Meningoencephalitis (ME), Sepsis (SI) or Other diagnoses (OD). Risk of psychiatric disorder was assessed 3-6 months after discharge with the Strengths and Difficulties Questionnaire Algorithm (SDQ) and risk of PTSD was assessed with the Impact of Event Scale (IES-8). Basal functioning of HPA and SAM were assessed through salivary cortisol and alpha-amylase determinations at awaking, 30 min and 12 hours after awaking over two consecutive weekdays. Results: Cases are 4.6 times (95% CI: 1.5-14.0) more likely to be at risk for meeting a DSM-IV diagnosis than controls. The risk is highest for anxiety-depressive disorders (7.1 times, 95% CI: 1.5-32.7), but is also significantly elevated for PTSD (4.0 times, 95%CI: 1.2-13.8) and conduct disorder (3.2 times, 95% CI; 1.0-9.8). Within PICU, PTSD symptoms are more prevalent in ME or SI than in the OD subgroup (16.0 points in the IES-8 scale, 95%CI: 10.1-21.8) and this can not be explained by differences in severity, or other characteristics of critical illness or PICU admission. Treatment with corticosteroids during PICU admission is associated to a statistically and clinical significant reduction in PTSD symptomatology (8.5 points in the IES-8 scale, 95%CI: 14.8-2.2.). A tendency for evening hypercortisolemia was found in cases, 3-6 months after discharge from PICU without evidence for additional alterations in the basal HPA or SAM functioning. Salivary cortisol 12 hours after awakening is positively associated to the risk of suffering any mental disorder, conduct disorder or PTSD. Similarly, a more prominent cortisol awakening response is associated to higher risk of anxiety/depressive or hyperactivity/inattention disorders. There is no association between psychological sequelae and any SAM system biological markers. Conclusions: Children who survive a critical illness have a high risk of psychiatric sequelae 3-6 months after PICU discharge. The risk is highest among those with infectious meningitis or sepsis. Treatment with corticosteroids is associated with a reduction of risk. There is also an association between the HPA basal function and the risk of psychiatric disorders.