White-Cell Derived Inflammatory Biomarkers in Prediction of Postoperative Delirium in Elderly Patients Undergoing Surgery for Lower Limb Fracture Under Non-General Anaesthesia

Abstract

Purpose The aim of this study was to investigate whether white-cell derived biomarkers could serve as potential markers in prediction of postoperative delirium (POD) after lower limb fracture. Patients and Methods Elderly patients with surgery for lower limb fracture under non-general anaesthesia were included. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and platelet-to-white cell ratio (PWR), which were most recently measured preceding surgery and measured within 24h after surgery, were calculated. Delirium was measured with Confusion Assessment Method (CAM) once daily from preoperative day 1 to postoperative day 3 or hospital discharge. Results The incidence of POD was 32.6% (60/184). Between patients with and those without POD, there were significant differences in preoperative hematological biomarkers (neutrophil count, lymphocyte count, NLR and PWR) and postoperative hematological biomarkers (white cell count, neutrophil count, lymphocyte count, NLR, PLR and PWR). More obvious changes before and after operation for NLR, PLR and C-reactive protein (CRP) were found in patients with POD. Multivariate logistic regression showed that benzodiazepines (OR, 7.912; 95% CI, 1.884–33.230; p = 0.005), change of CRP (OR, 1.017; 95% CI, 1.007–1.027; p = 0.001) and postoperative NLR (OR, 1.358; 95% CI, 1.012–1.823; p = 0.041) were associated with POD. When the changes of NLR, PLR and PWR entered multivariate logistic regression, older age (OR, 1.073; 95% CI, 1.001–1.149; p = 0.046), benzodiazepines (OR, 6.811; 95% CI, 1.652–28.081; p = 0.008), greater change of CRP (OR, 1.015; 95% CI, 1.006–1.023; p = 0.001) and greater change of NLR (OR, 1.266; 95% CI, 1.035–1.549; p = 0.022) were associated with increased risk of POD. Postoperative NLR had high accuracy to predict POD with area under curve (AUC) of 0.790 (95% CI 0.708 to 0.872). Conclusion Age, benzodiazepines, postoperative NLR, change of NLR and change of CRP were independent predictable markers for POD in elderly patients undergoing surgery for lower limb fracture under non-general anaesthesia. Early postoperative NLR may help to recognize POD as soon as possible.

Postoperative delirium in geriatric patients with hip fractures

“…High clinical significance can result from the identification of predictive biomarkers that allow for early risk stratification of hip fracture patients who are vulnerable to POD. The incidence and severity of POD in hip fracture patients were associated with higher levels of white blood cells, neutrophil/lymphocyte ratio, neutrophil percentage, and lower levels of mean platelet volume and basophil percentage ( Thisayakorn et al, 2021 ; Li et al, 2022 ), which further demonstrated that immune-inflammatory processes are involved in the pathophysiology of POD. Prognostic Nutritional Index (PNI) is a convenient and accurate way to quantify nutritional status, and it was calculated as 10 × albumins (g/dl) + 0.005 × total lymphocyte count (per mm 3 ; Onodera et al, 1984 ).…”

Systemic immune-inflammation index predicts postoperative delirium in elderly patients after surgery: a retrospective cohort study

“…This change in peripheral circulation may involve disrupting the blood-brain-barrier and microglia, which activates and releases cerebral cytokines, resulting in POD [22,24]. Second, many studies have found that white-cell derived inflammatory markers, such as the NLR, PLR, and PWR, are associated with delirium [11][12][13][14][15]. As one of the white-cell derived inflammatory markers, the SII was also calculated using neutrophil, lymphocyte, and platelet counts.…”

“…Compared with IL-6, IL-8, C-reactive protein, and S-100β, white-cell derived inflammatory biomarkers, namely, the neutrophil-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), platelet-to-white cell ratio (PWR), and systemic immune inflammation index (SII, platelet × neutrophil/lymphocyte), can be obtained for a lower cost and require less time. Some studies have shown the potential value of the NLR, PLR, and PWR in predicting POD after lower limb, head and neck free-flap reconstruction, total hip arthroplasty, abdominal surgery, oesophagectomy carotid endarterectomy, and cardiac surgery [11][12][13][14][15]. As a white-cell derived inflammatory biomarker, systemic immune inflammation index (SII) has been used to predict ischemic stroke, delayed vasospasm, microvascular dysfunction, and acute kidney injury [16][17][18][19].…”

Thoracic delirium index for predicting postoperative delirium in elderly patients following thoracic surgery: A retrospective case‐control study

“…Several studies noted that neuroinflammation might have a crucial effect on the progression of POD, and neutrophils and lymphocytes were the major effectors of neuroinflammation among elderly patients with delirium, manifested as increased neutrophil count and decreased lymphocyte count (Kotfis et al, 2019;Oh & Park, 2019). As studies mentioned, a high level of NLR has been identified as an independent risk factor for POD in acute ischemic stroke and orthopedic surgery (Guldolf et al, 2021;Li et al, 2022). Also, other inflammatory markers ratios, such as MLR and PLR, played a prominent role in predicting POD after cardiac surgery ( Şaşkin et al, 2022;Su et al, 2022).…”