Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio as prognostic predictors for delirium in critically ill patients: a systematic review and meta-analysis

Abstract

Introduction In this systematic review and meta-analysis, we aim to analyze the current literature to evaluate neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) values among critically ill patients who develop delirium as compared to those who do not. Methods PubMed, Web of Science, and Scopus were used to conduct a systematic search for relevant publications published before June 12, 2022. The Newcastle–Ottawa scale was used for quality assessment. Because a significant level of heterogeneity was found, we used the random-effects model to generate pooled effects. Results Twenty-four studies including 11,579 critically ill patients, of whom 2439 were diagnosed with delirium, were included in our meta-analysis. Compared with the non-delirious group, the delirious group's NLR levels were significantly higher (WMD = 2.14; CI 95% = 1.48–2.80, p < 0.01). In the subgroup analysis according to the type of critical condition, the NLR levels in patients of delirious group were significantly more than those of non-delirious group in studies on POD, PSD and PCD (WMD = 1.14, CI 95% = 0.38–1.91, p < 0.01, WMD = 1.38, CI 95% = 1.04–1.72, p < 0.001, and WMD = 4.22, CI 95% = 3.47–4.98, p < 0.001, respectively). However, compared with the non-delirious group, the delirious group's PLR levels were not significantly different (WMD = 1.74; CI 95% = -12.39–15.86, p = 0.80). Conclusion Our findings support NLR to be a promising biomarker that can be readily integrated into clinical settings to aid in the prediction and prevention of delirium.

The Role of Neutrophil-to-Lymphocyte Ratio (NLR) in Urosepsis-Associated Delirium

“…The study emphasises that systemic inflammation and oxidative stress play an important role in the pathophysiology of delirium [ 29 ]. Higher NLR levels might indicate inflammation and neuro-inflammation making patients more susceptible to delirium in the care unit (ICU) environment [ 30 ]. Our results showed that the value of NLR was significantly higher for patients with delirium (11.9 vs 8.7, p < 0.001) so we believe NLR may be a useful tool in early diagnosis of delirium in critically ill patients with urosepsis.…”

Neutrophil–Lymphocytes Ratio as Potential Early Marker for Alzheimer’s Disease

“…A wealth of evidence suggests that delirium may contribute to dementia through several mechanisms, such as inflammation [ 41 , 42 ]. Indeed, elevation to peripheral markers of inflammation, including NLR, has been found to be related with delirium occurrence [ 43 , 44 ]. Longitudinal investigations in patients with dementia may help to establish if NLR may be a predictive biomarker for delirium.…”

Increased IgA-mediated responses to the gut paracellular pathway and blood–brain barrier proteins predict delirium due to hip fracture in older adults

“…Delirium in older adults following hip fracture surgery is associated with increased white blood cell numbers and neutrophil/lymphocyte ratio indicating aseptic inflammation ( 11 ). A recent meta-analysis shows that the delirium diagnosis is associated with a higher neutrophil/lymphocyte ratio in various critical care settings ( 12 ). Furthermore, we showed that delirium is characterized by IRS activation and a relative deficiency in the compensatory immunoregulatory system (CIRS), which prevents hyperinflammation ( 13 ).…”