Inflammation biomarkers and delirium in critically ill patients

Abstract

IntroductionDelirium is a common occurrence in critically ill patients and is associated with an increase in morbidity and mortality. Septic patients with delirium may differ from a general critically ill population. The aim of this investigation was to study the relationship between systemic inflammation and the development of delirium in septic and non-septic critically ill patients.MethodsWe performed a prospective cohort study in a 20-bed mixed intensive care unit (ICU) including 78 (delirium = 31; non-delirium = 47) consecutive patients admitted for more than 24 hours. At enrollment, patients were allocated to septic or non-septic groups according to internationally agreed criteria. Delirium was diagnosed using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) during the first 72 hours of ICU admission. Blood samples were collected within 12 hours of enrollment for determination of tumor necrosis factor (TNF)-α, soluble TNF Receptor (STNFR)-1 and -2, interleukin (IL)-1β, IL-6, IL-10 and adiponectin.ResultsOut of all analyzed biomarkers, only STNFR1 (P = 0.003), STNFR2 (P = 0.005), adiponectin (P = 0.005) and IL-1β (P < 0.001) levels were higher in delirium patients. Adjusting for sepsis and sedation, these biomarkers were also independently associated with delirium occurrence. However, none of them were significant influenced by sepsis.ConclusionsSTNFR1, STNFR2, adiponectin and IL-1β were associated with delirium. Sepsis did not modify the relationship between the biomarkers and delirium occurrence.

Associations Between Delirium and Preoperative Cerebrospinal Fluid C‐Reactive Protein, Interleukin‐6, and Interleukin‐6 Receptor in Individuals with Acute Hip Fracture

“…No significant relationship was found between IL‐6 and delirium in serum or in CSF. Previous findings are conflicting, with some studies reporting higher serum IL‐6 levels in participants with delirium and others not detecting such a difference . A recent study of older adults without dementia undergoing elective surgery found no association between serum IL‐6 levels and delirium in the postanesthesia care unit but found higher serum IL‐6 levels in individuals with delirium on Postoperative Day 2 .…”

“…Likewise, previous studies on circulating levels of interleukin‐6 (IL‐6) in individuals with delirium are conflicting. Most studies have reported higher levels in participants with delirium, but others have not found a relationship . IL‐6 in CSF from individuals with delirium has been studied less.…”

The Association between Acute Respiratory Distress Syndrome, Delirium, and In-Hospital Mortality in Intensive Care Unit Patients

“…For example, inflammation has recently been shown to be an important contributor to delirium and long-term cognitive dysfunction (37)(38)(39)(40). Indeed, all ARDS patients in our cohort had severe sepsis at the time of ICU admission.…”

Systemic TNF-α produces acute cognitive dysfunction and exaggerated sickness behavior when superimposed upon progressive neurodegeneration

“…It is significant that in this model of acute systemic inflammation TNF-α alone is sufficient to induce acute dysfunction in a cognitive task reliant on attentional and working memory function, two key cognitive domains impaired in delirium. Associations between delirium and TNF-α in biomarker studies have sometimes (Adamis et al, 2011, Kazmierski et al, 2014), but not always (van den Boogaard et al, 2011, Ritter et al, 2014), been detected. The current data are certainly supportive of deleterious effects of systemic inflammation on short-term cognitive processes.…”