Effect of platelet-lymphocyte ratio and lactate levels obtained on mortality with sepsis and septic shock

The Neutrophil-to-Lymphocyte Ratio and the Platelet-to-Lymphocyte Ratio as Predictors of Mortality in Older Adults Hospitalized with COVID-19 in Peru

Background

The prognostic value of the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) in patients with COVID-19 is rarely described in older adults. We aimed to estimate the prognostic value of NLR and PLR, determining the mortality of adults over 60 years of age hospitalized for COVID-19 in three hospitals in Peru from March to May 2020.

Methods

We performed a secondary analysis of data from a retrospective cohort carried out in Lambayeque, Peru, from March 18 to May 13, 2020. Older adults hospitalized for COVID-19 were included. The outcome variable was in-hospital mortality by all causes, while the exposure variable was the NLR and PLR (categorized in tertiles and numerically, performing a logarithmic transformation). We included sociodemographic variables, comorbidities, vital functions, laboratory markers, and treatment received during hospital stay. We evaluated the association between NLR and PLR using the hazard ratio (HR) in a Cox regression model. We estimated HR with their respective 95% confidence intervals (95% CI). We estimated cumulative/dynamic time-dependent ROC curves and reported area under the curve ROC (AUC-ROC) for 15-, 30-, and 60-day mortality with their respective simultaneous confidence intervals (confidence bands (CB)). Also, we estimated an optimal cut-off point based on the maximally selected rank statistics.

Results

A total of 262 hospitalized older adults were analyzed, 71.8% (n = 188) of whom were male with a median age of 70 years (interquartile range: 65-78). The mean NLR and PLR were 16.8 (95% CI: 14.9-18.7; SD: 15.5) and 50.3 (95% CI: 44.6-55.9; SD: 46.3), respectively. The mortality rate was 68.7% (95% CI: 62.7-74.3). The adjusted Cox regression analysis showed that the high NLR (adjusted HR (aHR) = 2.12; 95% CI: 1.43-3.14) and PLR (aHR = 1.90; 95% CI: 1.30-2.79) tertiles were associated with a higher risk of mortality. The maximum AUC-ROC values at 60 days of follow-up for NLR and PLR were 0.713 (95%CB: 0.627-0.800) and 0.697 (95%CB: 0.583-0.754), respectively.

Conclusions

The NLR and PLR are predictors of higher risk of mortality, and these results suggest that both could be reliable and practical markers for the identification of older adults at high risk of mortality by COVID-19. NLR and PLR have prognostic value, with an AUC greater than 0.5; however, by themselves, they are weak prognostic markers. It is important to carry out future studies incorporating these two markers into preexisting models or designing new ones considering them.

Prognostic Value of Platelet to Lymphocyte Ratio in Sepsis: A Systematic Review and Meta-analysis

The goal of this study was to conduct a systematic review of the literature on the relationship between peripheral blood platelet to lymphocyte ratio (PLR) and mortality in sepsis and to integrate the findings in a meta-analysis. An electronic search of three main databases was performed: PubMed, Embase, and Scopus on 19 December 2021. Finally, 16 studies comprising 2403 septic patients, including 1249 survivors and 1154 nonsurvivors, were included in this meta-analysis. We found that PLR levels were significantly higher in nonsurvivors than in survivors (random effect model: SMD = 0.72, 95% CI; 0.35–1.10, p < 0.001). However, significant heterogeneity was observed across the studies (I² = 94.1%, p < 0.01). So, we used random effect model in our meta-analysis. In the subgroup analysis, according to mortality time, patients deceased during one month after sepsis had elevated levels of PLR compared to survivors (SMD = 1.03, 95% CI = 0.15-1.92, p = 0.22). However, in-hospital mortality was not associated with PLR level (SMD = 0.41, 95% CI = −0.18-0.99, p = 0.175). Our findings support PLR to be a promising biomarker that can be readily integrated into clinical settings to aid in the prediction and prevention of sepsis mortality.

Predictive Value of the Prognostic Nutrition Index for the Prognosis of Patients With Severe Burns Treated With the Meek Graft

The Meek technique is currently a key method for treating wounds in severely burned patients. The survival rate of skin grafts is an important factor affecting the success rate of treatment. The purpose of this study was to investigate the effect of the preoperative prognostic nutritional index (PNI) on the survival rate of skin grafts in patients treated with the Meek technique in the early stage of severe burns. We retrospectively analyzed the data of severely burned patients who were treated at the burn center between January 2013 and December 2019 and met the inclusion criteria. The albumin (ALB) level and lymphocyte count obtained 1 day before the operation was used to calculate the preoperative PNI (PNI = serum ALB level [g/L] + 5 × total number of peripheral blood lymphocytes [×109/L]). According to the survival rates of skin grafts 14 days after the operation, patients with severe burns were divided into a group with good skin graft survival (survival rate ≥75%, abbreviated as group G) and a group with poor skin graft survival (survival rate <75%, abbreviated as group P). Receiver-operating characteristic (ROC) curves and univariate and multivariate analyses were used to evaluate the predictive value of the preoperative PNI for the prognosis of patients treated with the Meek technique. One hundred and twenty-one patients were enrolled in this study. Groups G (n = 66 cases) and P (n = 55 cases) did not have significant differences in age, sex, and body mass index (P > .05). The total burned surface area, burn index, platelet-to-lymphocyte ratio, preoperative platelet count, operative time, total protein, albumin level, globulin level, and PNI were the risk factors affecting the survival of Meek grafts. The burn index was an independent risk factor for poor skin graft survival (odds ratio [OR]: 1.049, 95% confidence interval [CI]: 1.020-1.079; P < .05). The preoperative PNI was a protective factor against poor skin graft survival (OR: 0.646, 95% CI: 0.547-0.761; P < .05). The ROC curve determined that the optimal cut-off value for the preoperative PNI was 34.98. There were 59 cases with PNI > 34.98 (the high PNI group) and 62 cases with PNI < 34.98 (the low PNI group). The survival rate of skin grafts in patients with a high PNI was generally significantly higher than that of patients with a low preoperative PNI (P < .05). Five (8.47%) patients in the high PNI group died, compared with 16 (25.8%) patients in the low PNI group. The difference in the mortality rate between the two groups was significant (P < .05). Preoperative PNI can be used as a predictor of the survival rate of skin grafts in patients treated with the Meek technique in the early stage of severe burns.

Epidemiology and Prognostic Utility of Cellular Components of Hematological System in Sepsis

Background

Data are lacking on the role of cellular components of hematological system as biomarkers for prognosis of sepsis. We planned to identify if these parameters measured at admission to ICU and at 72 hours can be useful as prognostic marker in septic critically ill patients.

Materials and methods

In this prospective observational study, 130 adult patients with sepsis were recruited. Various hematological study parameters (total, differential, and absolute leukocyte count, platelet count, platelet distribution width, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio) were noted at day 1 and day 3 of admission. Primary outcome was 28-day mortality, and secondary outcomes were duration of mechanical ventilation, vasopressor requirement, ICU length of stay, and requirement of renal replacement therapy. The variables were compared between two groups and using binary regression model and were evaluated as prognostic markers for 28-day mortality.

Results

Data from n = 129 were analyzed. At day-28, n = 58 (44.96%) patients survived. Baseline and demographic parameters were comparable between survivors and nonsurvivors. Admission Sequential Organ Failure Assessment score was more in nonsurvivors than survivors [8 (6–8) vs 6 (4–8); p = 0.002]. In nonsurvivors, monocyte, lymphocyte, basophil, eosinophil, and platelet count were significantly less at day 1 and lymphocyte, eosinophil, basophil and platelet count were significantly less at day 3. NLR and PLR at day 3 were significantly more in nonsurvivors. On logistic regression analysis, age, thrombocytopenia on day 1, and low eosinophil count on day 3 predicted 28-day mortality (p = 0.006, p = 0.02, and p = 0.04, respectively).

Conclusion

Thrombocytopenia on day 1 and eosinopenia on day 3 may predict 28-day mortality in sepsis.

How to cite this article

Sinha H, Maitra S, Anand RK, Aggarwal R, Rewari V, Subramaniam R, et al. Epidemiology and Prognostic Utility of Cellular Components of Hematological System in Sepsis. Indian J Crit Care Med 2021;25(6):660–667.

Effect of lymphocyte-to-monocyte ratio on survival in septic patients: an observational cohort study

Introduction

The purpose of the present study was to evaluate the potential relationship of lymphocyte-to-monocyte ratio (LMR) with outcomes of septic patients at intensive care unit (ICU) admission.

Material and methods

3087 septic patients were included in the final cohort by using the Medical Information Mart for Intensive Care (MIMIC) database. We evaluated the association of different groups of LMRmax with 28-day survival and 1-year survival via Kaplan-Meier (K-M) analysis and Cox regression analysis. Subgroups analysis of LMRmax was performed to further explore the effect of LMRmax on survival.

Results

According to the optimal cut-off value, the cohort was divided into low-LMRmax and high-LMRmax groups. The 28-day and 1-year survival rates were 47.9% and 19.9%, respectively, in the low-LMRmax group, and 60.4% and 25.9%, respectively, in the high-LMRmax group. Univariate logistic regression and K-M analyses revealed that the 28-day and 1-year survival rates of the high-LMRmax group were higher than those of the low-LMRmax group (both p < 0.001). A subgroup analysis of LMRmax identified a significant stepwise decrease in the risk of death at 28 days and 1 year from group 1 to group 4 (LMRmax increased gradually) after adjustment for multiple variables.

Conclusions

We report for the first time that a lower LMRmax value is independently predictive of a poor prognosis in septic patients. Therefore, as an inexpensive and readily available indicator, LMRmax may facilitate stratification of prognosis in septic patients.

Lactate and NEWS-L are fair predictors of mortality in critically ill geriatric emergency department patients

INTRODUCTION

In this study, we aimed to investigate the prognostic power of the first lactate level measured in the emergency department (ED), National Early Warning Score (NEWS), and NEWS-lactate (NEWS-L) on ED admission in critically ill geriatric patients.

METHODS

This retrospective observational study was conducted in the ED of a university hospital. Consecutive patients ≥65 years of age admitted to our ED between July 1, 2017, and December 31, 2017, and transferred to the intensive care unit after the ED follow-up period were included in the study. The predictive performances of lactate, NEWS, and NEWS-L in terms of in-hospital mortality were compared.

RESULTS

A total of 455 patients were included in the statistical analyses. The in-hospital mortality rate was 22.9%. The mean lactate, NEWS, and NEWS-L of non-survivors was significantly higher than those of survivors (2.9 ± 2.2 vs. 1.9 ± 1.5 mmol/L, 8.9 ± 4.1 vs. 6.1 ± 3.7, and 11.8 ± 5.0 vs. 8.1 ± 4.4, respectively, for all p < 0.001). The AUCs of the lactate, NEWS, and NEWS-L were respectively 0.654 (95% CI 0.594-0.713), 0.686 (95% CI 0.628-0.744), and 0.714 (95% CI 0.658-0.770) in predicting in-hospital mortality.

CONCLUSIONS

According to the results of this study, we conclude that ED admission lactate level and NEWS are low-accuracy predictors of in-hospital mortality in critically ill geriatric patients. Although the combination of lactate level with physiological parameters increases the predictive performances of both parameters, NEWS-L is still not a powerful predictor to make definitive clinical decisions for critically ill geriatric ED patients.

Timing of Repeated Lactate Measurement in Patients With Septic Shock at the Emergency Department

BACKGROUND

The objective of this study was to evaluate the prognostic value of lactate levels during the first 12 hours after shock development and to identify the optimal timing for repeated lactate measurements in patients with septic shock.

METHODS

We conducted a retrospective cohort study using a prospective data registry, and enrolled 2,226 consecutive adult patients with septic shock between January 2010 and December 2015. Blood lactate was measured at shock development, and after 2, 4, 6 and 12 hours (T₀, T₂, T₄, T₆ and T₁₂) during protocol-driven resuscitation bundle therapy. The prognostic value of lactate levels for 28-day mortality was analyzed using logistic regression and receiver operating characteristic curve analysis.

RESULTS

A total of 829 patients with septic shock were included in the study, among whom 211 died during the study period. The lactate levels at each time point were associated with increased 28-day mortality, and the lactate level at 6 hours had the greatest prognostic value (area under the curve of T₀ = 0.61; T₂ = 0.65; T₄ = 0.69; T₆ = 0.72 and T₁₂ = 0.62, and odds ratio (OR) of T₀, 1.17 [95% CI: 1.11-1.23]; T₂, 1.23 [95% CI: 1.17-1.30]; T₄, 1.30 [95% CI: 1.22-1.38]; T₆, 1.33 [95% CI: 1.26-1.42] and T₁₂, 1.24 [95% CI: 1.19-1.30]). Hyperlactatemia over 2mmol/L and 4mmol/L at 6 hours from shock was associated with 4-times higher mortality (≥2mmol/L, OR = 3.89 [95% CI: 2.48-6.09]; ≥4mmol/L, OR = 3.93 [95% CI: 2.83-5.44]).

CONCLUSIONS

During the first 12 hours following shock development, the optimal time point of repeated blood lactate measurement was 6 hours, which was the greatest prognostic value for mortality.