Neutrophil-Lymphocyte Ratio as a Potential Biomarker for Delirium in the Intensive Care Unit

Abstract

Background: Recognition and early detection of delirium in the intensive care unit (ICU) is essential to improve ICU outcomes. To date, neutrophil-lymphocyte ratio (NLR), one of inflammatory markers, has been proposed as a potential biomarker for brain disorders related to neuroinflammation. This study aimed to investigate whether NLR could be utilized in early detection of delirium in the ICU.Methods: Of 10,144 patients who admitted to the ICU, 1,112 delirium patients (DE) were included in the current study. To compare among inflammatory markers, NLR, C-reactive protein (CRP), and white blood cell (WBC) counts were obtained: the mean NLR, CRP levels, and WBC counts between the initial day of ICU admission and the day of initial delirium onset within DE were examined. The inflammatory marker of 1,272 non-delirium patients (ND) were also comparatively measured as a supplement. Further comparisons included a subgroup analysis based on delirium subtypes (non-hypoactive vs. hypoactive) or admission types (elective vs. emergent).Results: The NLR and CRP levels in DE increased on the day of delirium onset compared to the initial admission day. ND also showed increased CRP levels on the sixth day (the closest day to average delirium onset day among DE) of ICU admission compared to baseline, while NLR in ND did not show significant difference over time. In further analyses, the CRP level of the non-hypoactive group was more increased than that of the hypoactive group during the delirium onset. NLR, however, was more significantly increased in patients with elective admission than in those with emergent admission.Conclusion: Elevation of NLR was more closely linked to the onset of delirium compared to other inflammatory markers, indicating that NLR may play a role in early detection of delirium.

High Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios Are Associated with a Higher Risk of Hemodialysis Vascular Access Failure

“…The mean NLR was 6.32 ± 3.12 whereas the mean PLR was 238.92 ± 105. 23. The mean values of both the NLR and PLR were statistically different between the groups of functioning and non-functioning AVFs: NLR 3.55 ± 1.62 vs. 8.27 ± 6.7 (p-value = 0.0001) and PLR 194 ± 89.7 vs. 266 ± 170 (p-value = 0.001), respectively.…”

“…The NLR is becoming an important tool for clinical practice as a surrogate of the systemic inflammation index. It has already been linked with several clinical scenarios such as cardiovascular [ 17 , 18 , 19 ], oncological [ 20 , 21 ], and many other medical and surgical fields [ 22 , 23 ].…”

Preoperative Status of Gut Microbiota Predicts Postoperative Delirium in Patients With Gastric Cancer

“…Kawano et al ( 37 ) have been found that the neuro-inflammation was significantly correlated with delirium. Seo et al ( 38 ) also suggested that neutrophil-lymphocyte ratio could be deserved as a biomarker in delirium. We speculated that the alteration of gut bacteria related neuro-inflammation after abdominal surgery would be a potential influencing factor in the incidence of POD.…”

Delirium-related factors and their prognostic value in patients undergoing craniotomy for brain metastasis

“…Given that the influence of occurrence of postoperative hematoma at the resection site on delirium was the most notable finding regardless of the location, the effect of hematoma itself should be the focus. Delirium is known to be closely related to neuroinflammation, which can be assessed by the increased neutrophil-to-lymphocyte ratio or C-reactive protein level ( 34 ). Considering that hematoma can not only cause regional swelling, but also regional febrile and inflammatory responses ( 35 ), our findings might be linked to the neuro-inflammation hypothesis of delirium ( 36 ).…”