ALL Metrics
-
Views
-
Downloads
Get PDF
Get XML
Cite
Export
Track
Study Protocol

A cross-sectional study of neutrophil to lymphocyte ratio as a prognostic marker in acute organophosphorus poisoning in a tertiary care hospital in Central India

[version 1; peer review: 2 not approved]
PUBLISHED 25 Apr 2024
Author details Author details
OPEN PEER REVIEW
REVIEWER STATUS

This article is included in the Datta Meghe Institute of Higher Education and Research collection.

Abstract

Background

Acute organophosphorus poisoning remains a significant public health concern, with variable clinical outcomes. Prognostic markers are crucial for patient management and risk stratification. This study aims to investigate the Neutrophil Lymphocyte Ratio (NLR) as a potential prognostic marker and its associations with severity and clinical outcomes in acute organophosphorus poisoning.

Methods

This cross-sectional observational study will be conducted over two years, involving patients presenting with acute organophosphorus poisoning in the Medicine Ward and Intensive Care Unit of DMIHER Wardha. Informed consent will be obtained, and detailed clinical assessments, laboratory investigations, and NLR calculations will be performed. The Nambaet, Peradeniya, and Bardin classification scales will be used to measure severity. Statistical methods will be applied to explore the relationships between NLR, clinical parameters, and clinical outcomes, including descriptive statistics, bivariate analysis, correlation analysis, multivariate regression, and ROC analysis.

Expected Results

The study is anticipated to elucidate the role of NLR as a prognostic marker in acute organophosphorus poisoning. Initial assessments and correlations between NLR and clinical parameters will be presented. The predictive capability of NLR for clinical outcomes, including the need for ventilatory support and length of hospital stay, will be explored. Agreement and discrepancies between the classification scales will be evaluated.

Keywords

Organophosphorus Poisoning, Neutrophil to Lymphocyte Ratio, Prognostic Marker, Severity Classification, Clinical Outcomes, Risk Stratification

Introduction

Organophosphorus compounds are widely used in agriculture, industry, and households, playing a pivotal role in pest control and producing various essential products. However, their ubiquitous presence poses a considerable risk to human health, primarily due to unintentional exposures and deliberate self-harm incidents.1 Acute organophosphorus poisoning, resulting from the inhibition of acetylcholinesterase and the accumulation of acetylcholine, leads to a broad spectrum of clinical manifestations, ranging from mild symptoms to life-threatening toxicity. Effective management of acute organophosphorus poisoning demands early identification of severity and prognostication, as it significantly influences treatment decisions and clinical outcomes.2

Identifying reliable prognostic markers has been an ongoing pursuit in toxicology, aiming to enhance risk stratification and guide therapeutic strategies.3 The Neutrophil to Lymphocyte Ratio (NLR), an inflammatory marker, has gained recognition for its potential utility in various medical conditions. Its role as a prognostic marker in acute organophosphorus poisoning has piqued interest due to its simplicity and availability as part of routine blood tests.4

This cross-sectional study investigates the NLR as a potential prognostic marker in acute organophosphorus poisoning. By assessing its associations with the severity of poisoning and clinical outcomes, we aim to contribute to a deeper understanding of NLR’s role in patient management. Our study will utilise established severity classification scales, including the Nambaet, Peradeniya, and Bardin classifications, to comprehensively evaluate the severity of poisoning and to compare their agreement and discrepancies.

In the era of evidence-based medicine, the quest for novel prognostic markers that can facilitate informed clinical decisions is of paramount importance. This study endeavours to shed light on the utility of the NLR as a potential prognostic marker in acute organophosphorus poisoning, aiming to improve patient outcomes and refine therapeutic approaches in this critical area of toxicology.

Aim

This study aims to investigate the potential utility of the Neutrophil Lymphocyte Ratio as a prognostic marker in patients with acute organophosphorus poisoning.

Objectives

  • 1. To determine the Neutrophil Lymphocyte Ratio in patients with acute organophosphorus poisoning.

  • 2. To evaluate the relationship between the Neutrophil Lymphocyte Ratio and the severity of organophosphorus poisoning as classified by the Nambaet classification, Peradeniya organophosphorus poisoning scale, and Bardin classification.

  • 3. To assess whether an elevated neutrophil-to-lymphocyte ratio is associated with the need for ventilatory support in these patients.

  • 4. To investigate whether the Neutrophil to Lymphocyte Ratio is correlated with the dose of atropine administered to patients with acute organophosphorus poisoning.

  • 5. To examine if the Neutrophil to Lymphocyte Ratio can predict the length of hospital stay in patients with acute organophosphorus poisoning.

Method

Study design

This study employs a cross-sectional, observational design to investigate the Neutrophil Lymphocyte Ratio as a potential prognostic marker in patients with acute organophosphorus poisoning. Data will be collected at a single time point setup for the 2023-2024 period.

Study population

The study population consists of patients who have presented with acute organophosphorus poisoning. These patients will be recruited from the Medicine Ward and Medicine Intensive Care Unit of DMIHER Wardha.

Place of study

The study will be conducted in the Acharya Vinoba Bhave Rural Hospital Department of Medicine.

Inclusion criteria

  • 1. Patients with a confirmed history of oral ingestion of organophosphorus compounds.

  • 2. Patients who present at the casualty department or are admitted to the Medicine Ward or Medicine Intensive Care Unit of DMIHER Wardha within 24 hours of organophosphorus compound ingestion.

  • 3. Patients who provide informed consent to participate in the study.

  • 4. Patients of all age groups, regardless of gender.

Exclusion criteria

  • 1. Patients who decline to provide informed consent.

  • 2. Patients exposed to poisons or compounds other than organophosphorus.

  • 3. Patients with severe chronic comorbidities, including liver cirrhosis, symptomatic heart failure (New York Heart Association class III or IV), end-stage chronic kidney disease (on regular hemodialysis), and chronic obstructive pulmonary disease (COPD).

  • 4. Patients diagnosed with malignancies.

Bias

  • 1. Selection bias: There is a risk that patients who agree to participate in the study may only be representative of some patients with acute organophosphorus poisoning. To mitigate this bias, researchers should use a random or consecutive sampling approach when recruiting participants to ensure that the sample is as representative as possible.

  • 2. Information bias: This can occur if there are inaccuracies or inconsistencies in data collection or measurements. To minimise this bias, researchers should employ standardised data collection tools and procedures, ensure that data collectors are trained, and perform regular quality checks on the collected data.

  • 3. Observer bias: In the context of this study, observer bias could occur when healthcare providers assess and classify patients differently based on their judgments. To address this, researchers should provide clear guidelines and criteria for assessing organophosphorus poisoning severity, ensuring the assessment is consistent among different observers.

Enrollment process

  • 1. Patient identification: Patients admitted to the Medicine Ward or Medicine Intensive Care Unit of DMIHER Wardha with a history of acute organophosphorus poisoning will be identified for enrollment.

  • 2. Informed consent: The first step in enrollment is obtaining informed consent. Patients or their legally authorised representatives will be approached, and the study will be explained in detail, including its purpose, procedures, risks, and benefits. Consent forms in the appropriate language will be provided to the patients or representatives. If the patient is not in a state to provide informed consent, it will be obtained from their relatives.

  • 3. Screening for inclusion and exclusion criteria: After obtaining informed consent, patients will be screened to ensure they meet the inclusion and exclusion criteria defined in the study protocol. Patients who meet these criteria will proceed to the next steps.

  • 4. Baseline data collection: Upon enrollment, baseline data will be collected, which includes demographic information, clinical history, and relevant medical information.

  • 5. Clinical assessments: Patients will undergo clinical assessments, including vital signs and a physical examination. These assessments will provide the necessary data for the classification scales (Nambaet classification, Peradeniya classification, and Bardin classification).

  • 6. Blood sample collection: Blood samples will be collected during the study procedures. These samples will be used to determine the Neutrophil Lymphocyte Ratio, which is one of the main parameters of interest in the study.

  • 7. Grading of severity: The severity of organophosphorus poisoning will be graded using the three classification scales. Clinical parameters and laboratory results will be considered in these assessments.

  • 8. Data recording: All collected data, including clinical assessments, blood test results, and classification scale scores, will be carefully recorded in designated proforma or electronic data management systems.

  • 9. Follow-up: Depending on the study objectives, patients may be followed up during their hospital stay to assess outcomes such as the need for ventilatory support, dose of atropine, and hospital stay duration.

  • 10. Data analysis: After data collection is complete, the collected data will be analysed to address the study’s objectives and assess the Neutrophil Lymphocyte Ratio as a prognostic marker in acute organophosphorus poisoning.

Data collection process

  • 1. Informed consent: Following a detailed explanation of the study to prospective participants, informed consent will be meticulously acquired from those individuals who meet the study’s inclusion criteria.

  • 2. Clinical assessment in intensive care: Within the confines of the Medicine Intensive Care Unit and ward, subjects will meticulously evaluate their vital signs. This will entail the thorough monitoring of critical physiological parameters.

  • 3. Laboratory blood investigations: Blood tests in the centralised clinical laboratory will be conducted, including a complete blood count (CBC) and potentially other relevant assays. These laboratory results will be instrumental in assessing the participants’ health status.

  • 4. Data recording: All pertinent values and findings derived from these assessments will be meticulously recorded in dedicated proforma, maintaining a precise record of the patient’s clinical data.

  • 5. Clinical history collection: A comprehensive clinical history, particularly related to the organophosphorus poisoning episode, will be systematically gathered from the participants. This will be performed per the pre-established inclusion and exclusion criteria.

  • 6. Patient guidance: Participants will be comprehensively briefed on the importance of ongoing vital sign monitoring and further scheduled blood investigations. Clear instructions will be provided to ensure their understanding and compliance with these critical aspects of care.

  • 7. Blood sample collection: In line with the study’s requirements, blood samples will be skillfully obtained from the study subjects, adhering to the established medical protocols and with due regard for patient comfort.

  • 8. Severity grading: The severity of organophosphorus poisoning will be meticulously graded by employing three distinct classification systems, namely the Nambaet classification, the Peradeniya classification, and the Bardin classification. These classifications provide a multidimensional assessment of the patient’s clinical condition.

  • 9. Nambaet classification: This evaluation method will involve a thorough assessment of various clinical parameters and the measurement of acetylcholinesterase levels to determine the severity of organophosphorus poisoning according to the Nambaet classification.5

  • 10. Peradeniya classification: The Peradeniya classification will be assigned based on the assessment of various clinical parameters, and specific scores will be allocated for each parameter, allowing for a more comprehensive understanding of the patient’s condition.6

  • 11. Bardin classification: The Bardin classification employs a criterion-based system, where the presence of two or more specific criteria will lead to assigning a specific grade. Patients who do not meet at least two criteria will be placed in the preceding category. This approach provides a nuanced assessment of severity based on clinical criteria.7

  • 12. Initial assessment: Upon admission, all three classification scales will be meticulously applied to the study participants, allowing for an early and comprehensive evaluation of their condition and providing a valuable baseline for further analysis. This initial assessment is a critical reference point for the study’s objectives.

Sample size

Sample size: Minimum sample size required

Formula

N=Z1α/22p(1p)D2.
Z1α/2=1.96,at 5% level of significance

P = Proportion of death for organ phosphorous poisoning having Neutrophil lymphocyte ratio >12 = 10.2% (As per reference article4)

D = estimated error (6%) = 0.06=(1.96)2(0.102)(10.898)/(0.06)2=98

Statistical method

The study will employ diverse statistical techniques to analyse the data comprehensively. Initially, descriptive statistics will be harnessed to provide a clear snapshot of the study population, offering insights into baseline characteristics. This will encompass measures such as means, standard deviations, medians, interquartile ranges for continuous variables, and frequencies and percentages for categorical variables. Bivariate analysis will be pivotal in exploring relationships between different variables. For instance, the Neutrophil to Lymphocyte Ratio will be scrutinised across severity categories using appropriate statistical tests like t-tests, ANOVA, or non-parametric tests tailored to the data distribution. Correlation analysis, featuring statistical measures like Pearson’s correlation coefficient or Spearman’s rank correlation, will unveil the intricate relationships between continuous variables, including the Neutrophil Lymphocyte Ratio and other pertinent clinical parameters.

In cases where independence and associations are sought, multivariate regression models will come into play. Multiple linear regression will uncover factors associated with the Neutrophil Lymphocyte Ratio. In contrast, logistic regression will predict outcomes such as the need for ventilatory support or the severity of organophosphorus poisoning. Given the utilisation of multiple classification scales (Nambaet, Peradeniya, Bardin), statistical tests like kappa statistics or concordance analyses will be instrumental in evaluating the agreement or disparities between these scales when assessing the severity of poisoning.

Subgroup analyses will investigate variations in associations between variables, such as the Neutrophil Lymphocyte Ratio and outcomes, within diverse study population subgroups, such as age, gender, or comorbid conditions. Furthermore, the diagnostic accuracy of the Neutrophil Lymphocyte Ratio will be quantified using Receiver Operating Characteristic (ROC) analysis, with the Area Under the ROC Curve (AUC) offering a measure of its prognostic potential. If relevant, survival analysis techniques, including Kaplan-Meier curves and Cox regression, will be employed to examine the link between the Neutrophil Lymphocyte Ratio and time-to-event outcomes like the length of hospital stay.

Sensitivity analyses will be conducted to ensure the robustness of results and assess the influence of potential confounders or bias. All statistical analyses will be executed with appropriate statistical software, such as SPSS version 23, under the guidance of qualified statisticians and proficient researchers well-versed in statistical methods. Significance levels will be diligently observed, with standard thresholds like p < 0.05 utilised to assess statistical significance.

Ethical considerations

The Institutional Ethics Committee of Datta Meghe Institute of Higher Education and Research (DU) has granted its approval to the study protocol (Reference number: DMIHER (DU)/IEC/2022/941. Date:11-04-2023) CTRI registration- REF/2023/07/070131. Before commencing the study, we will obtain written informed consent from all participants, providing them with a comprehensive explanation of the study’s objectives.

Dissemination

After the completion of the study, we will publish it in an indexed journal or conference.

Study status

The study has yet to start after the publication of the protocol; we will start recruitment in the study.

Discussion

Acute organophosphorus poisoning is a significant public health issue in many parts of the world, presenting clinicians with a diverse range of clinical manifestations and challenges in management. This study protocol outlines a comprehensive investigation into the potential use of the Neutrophil to Lymphocyte Ratio (NLR) as a prognostic marker in acute organophosphorus poisoning, aiming to shed light on its associations with disease severity and clinical outcomes.

The rationale for this study is grounded in the need for reliable prognostic markers to guide clinical decision-making in cases of acute organophosphorus poisoning. A review of existing literature reveals that despite advances in the management of poisoning cases, identifying markers that can help predict patient outcomes remains a critical research frontier.8 The systemic inflammation response, as represented by the NLR, has been studied extensively in various medical conditions, including poisoning scenarios.9,10 By delving into the relationship between NLR and organophosphorus poisoning, this study aligns itself with the broader research exploring the predictive potential of NLR in clinical settings.

Our study’s methodological rigor, including a cross-sectional design and a sizable sample size, will bolster the reliability of the findings. Consistent with prior studies,11 we anticipate that NLR will be associated with the severity of poisoning, reflected in the clinical parameters and the classification scales used in this study. In line with international guidelines,12,13 this approach ensures that the grading of poisoning severity is both comprehensive and comparable, providing a foundation for assessing the utility of NLR as an additional prognostic tool.

This study’s findings will contribute to a growing body of research on NLR in clinical prognostication, with relevance extending beyond organophosphorus poisoning. NLR has been previously identified as a prognostic marker in a range of medical conditions, such as acute kidney injury,14 cardiovascular diseases,15 and sepsis,16 underscoring its versatility in clinical prediction. By exploring its applicability in the context of poisoning, this study adds a valuable dimension to the ongoing discourse on NLR as a universal prognostic marker.

Furthermore, this protocol aligns with the call for further research into acute poisoning scenarios, particularly those involving organophosphorus compounds.17 Acute poisoning can lead to rapid clinical deterioration, making early prognostication crucial for timely and effective interventions.18 As such, the results of this study could hold substantial implications for clinicians, public health practitioners, and policymakers, with the potential to influence clinical guidelines for organophosphorus poisoning management.

Comments on this article Comments (0)

Version 1
VERSION 1 PUBLISHED 25 Apr 2024
Comment
Author details Author details
Competing interests
Grant information
Copyright
Download
 
Export To
metrics
Views Downloads
F1000Research - -
PubMed Central
Data from PMC are received and updated monthly.
- -
Citations
CITE
how to cite this article
Pradeep U and Mahajan DS. A cross-sectional study of neutrophil to lymphocyte ratio as a prognostic marker in acute organophosphorus poisoning in a tertiary care hospital in Central India [version 1; peer review: 2 not approved]. F1000Research 2024, 13:387 (https://doi.org/10.12688/f1000research.144250.1)
NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article.
track
receive updates on this article
Track an article to receive email alerts on any updates to this article.

Open Peer Review

Current Reviewer Status: ?
Key to Reviewer Statuses VIEW
ApprovedThe paper is scientifically sound in its current form and only minor, if any, improvements are suggested
Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.
Not approvedFundamental flaws in the paper seriously undermine the findings and conclusions
Version 1
VERSION 1
PUBLISHED 25 Apr 2024
Views
4
Cite
Reviewer Report 22 Aug 2024
Deepak Kumar, PGIMER, Chandigarh, India 
Not Approved
VIEWS 4
Dear Editor

I have gone through the manuscript (study protocol) titled “A cross-sectional study of neutrophil to lymphocyte ratio as a prognostic marker in acute organophosphorus poisoning in a tertiary care hospital in Central India”.

... Continue reading
CITE
CITE
HOW TO CITE THIS REPORT
Kumar D. Reviewer Report For: A cross-sectional study of neutrophil to lymphocyte ratio as a prognostic marker in acute organophosphorus poisoning in a tertiary care hospital in Central India [version 1; peer review: 2 not approved]. F1000Research 2024, 13:387 (https://doi.org/10.5256/f1000research.158011.r305572)
NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article.
Views
9
Cite
Reviewer Report 07 Jun 2024
Epari Venkatarao, Department of Community Medicine, Institute of Medical & Sum Hospital, Siksha ‘O’ Anusandhan, Bhubaneswar, Odisha, India 
Not Approved
VIEWS 9
This is a protocol for publication before the research is being conducted. It talks about finding the ability of NLR as a prognostic indicator in organophosphorus poisoning. NLR as a prognostic indicator has been studied extensively in recent times in ... Continue reading
CITE
CITE
HOW TO CITE THIS REPORT
Venkatarao E. Reviewer Report For: A cross-sectional study of neutrophil to lymphocyte ratio as a prognostic marker in acute organophosphorus poisoning in a tertiary care hospital in Central India [version 1; peer review: 2 not approved]. F1000Research 2024, 13:387 (https://doi.org/10.5256/f1000research.158011.r277315)
NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article.

Comments on this article Comments (0)

Version 1
VERSION 1 PUBLISHED 25 Apr 2024
Comment
Alongside their report, reviewers assign a status to the article:
Approved - the paper is scientifically sound in its current form and only minor, if any, improvements are suggested
Approved with reservations - A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.
Not approved - fundamental flaws in the paper seriously undermine the findings and conclusions
Sign In
If you've forgotten your password, please enter your email address below and we'll send you instructions on how to reset your password.

The email address should be the one you originally registered with F1000.

Email address not valid, please try again

You registered with F1000 via Google, so we cannot reset your password.

To sign in, please click here.

If you still need help with your Google account password, please click here.

You registered with F1000 via Facebook, so we cannot reset your password.

To sign in, please click here.

If you still need help with your Facebook account password, please click here.

Code not correct, please try again
Email us for further assistance.
Server error, please try again.