European Journal of Cardiovascular Medicine

Sepsis is a life-threatening medical condition that arises when the body's response to infection becomes uncontrolled, leading to widespread inflammation, tissue damage, and potential organ failure.¹ It can progress in severity, ranging from sepsis to septic shock, a critical state in which blood pressure drops dangerously low and tissues do not receive adequate oxygen, even with fluid resuscitation². This condition results in impaired tissue perfusion, increased anaerobic metabolism, and subsequent lactate accumulation due to the body's reliance on glycolysis for energy. Despite the best available treatments, including antibiotics, fluids, vasopressors, and organ support, the mortality rate for patients with severe sepsis or septic shock remains alarmingly high, sometimes exceeding 50%.In 2016, the Sepsis-3 criteria were introduced to improve the clinical identification of sepsis. According to these criteria, sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection³, often indicated by an increase of two or more points in the Sequential Organ Failure Assessment (SOFA) score. Additionally, the presence of Systemic Inflammatory Response Syndrome (SIRS) criteria—such as fever or hypothermia, tachycardia, tachypnea, and abnormal white blood cell counts—helps identify individuals who may be at risk of developing sepsis.The primary aim in managing sepsis is to swiftly restore adequate oxygen and nutrient delivery to tissues and improve cellular oxygen utilization. One of the most important laboratory markers in this process is serum lactate. Elevated lactate levels indicate tissue hypoxia and poor perfusion, serving as an early and reliable prognostic marker for clinical deterioration⁴. Because venous lactate levels are easy to obtain and comparable to arterial values, lactate monitoring has become an integral part of sepsis treatment protocols and risk stratification tools.To further evaluate disease severity and prognosis in sepsis patients, clinical scoring systems and biomarkers are often employed. Two such tools are Red Cell Distribution Width (RDW) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) score. RDW, which is included in a routine complete blood count (CBC), measures the variation in red blood cell (RBC) size⁵. Though commonly used to diagnose anemia and nutritional deficiencies, RDW can also reflect broader physiological disturbances in critically ill patients. Increased RDW values may indicate ineffective erythropoiesis or systemic inflammation, although they are not directly correlated with the severity of illness.In contrast, the APACHE II score is a comprehensive system designed to assess the severity of disease in critically ill patients. It incorporates multiple physiological parameters—such as temperature, mean arterial pressure, heart rate, respiratory rate, and serum values—along with age and chronic health status. The score ranges from 0 to 71, with higher scores indicating increased disease severity and a higher risk of mortality.⁶This study aims to compare RDW with APACHE II as early prognostic indicators in patients admitted with severe sepsis. By evaluating the correlation between RDW levels, APACHE II scores, and clinical outcomes, the study seeks to determine which marker is more effective in predicting prognosis.^7,8 Ultimately, improved prognostic assessment can lead to more timely and targeted interventions, potentially improving survival rates in patients with severe sepsis.

AIM

To make comparison of Red Cell Distribution Width with APACHE 2 in patients of Severe Sepsis.

This prospective study was conducted from March 2023 to August 2024 at Mahatma Gandhi Medical College & Hospital, Jaipur. The study received prior approval from the Institute Ethics Committee, and written informed consent was obtained from all participants before enrollment. The study focused on evaluating patients diagnosed with sepsis who presented to the inpatient department (IPD), High Dependency Unit (HDU), and Intensive Care Unit (ICU) of Mahatma Gandhi Hospital, Jaipur, and who met the inclusion criteria. The inclusion criteria consisted of all patients aged between 18 and 65 years who were clinically diagnosed with sepsis and required ICU or HDU admission. Patients who did not require ICU admission were excluded from the study. Additionally, individuals with pre-existing medical conditions such as renal, hepatic, endocrinal, or cardiac illnesses, as well as those with anemia or thalassemia, were excluded to avoid confounding variables. This careful selection ensured that the study population accurately represented patients with severe sepsis, enabling a focused assessment of prognostic indicators like Red Cell Distribution Width (RDW) and APACHE II scores.

Table 1 Age Distribution of Patients (n=70)

The mean age of patients is 51.72 ± 17.8 years. The majority of cases fall within the 41-50 years age group (30%), followed by 31-40 years (23%) and 51-60

years (20%). Only 1% of cases are under 20 years, and 4% are over 70 years.

This suggests that middle-aged and elderly individuals make up the bulk of the study population, indicating the vulnerability of these age groups to sepsis.

Figure 3 &4 :Presenting Complaints and  Systemic Examination Findings (N=70)

The most common presenting complaint was fever (87.1%), followed by shortness of breath (70%) and altered mental status (54.3%). Hypotension was present in 44.3% of cases. These findings are consistent with common clinical presentations of sepsis.

The most common systemic finding was tachycardia (81.4%), followed by crackles in the respiratory system (55.7%) and confusion in the central nervous system (54.3%). Abdominal distention was observed in 31.4% of patients, possibly indicating gastrointestinal involvement.

Table 2: Arterial Blood Gas (ABG) Analysis

The ABG analysis showed an average pH of 7.2 ± 0.2, indicating metabolic acidosis in many patients. The pO2 levels (70 ± 15 mmHg) were below normal, reflecting respiratory compromise and hypoxia in sepsis.

Table 3: Distribution of Patients by APACHE 2 Score

Majority of sepsis patients admitted have higher APACHE 2 score in our study population.

Table 4: Distribution of Patients by RDW Values

Majority of Patients in Higher RDW Categories: Most patients (88.6%) have RDW values greater than 14%, with the largest group being those with RDW > 16% (45.7% of patients). Elevated RDW values (>16%) may indicate underlying inflammation, nutritional deficiencies (e.g., iron, B12), or chronic disease.

Table 5 Clinical outcomes of patients

The length of hospital stay was significantly longer in non-survivors (12.79 days) compared to survivors (8.33 days, p=0.001). The incidence of multiple organ dysfunction (MOD) was significantly higher in non-survivors (82%) compared to survivors (37.33%).

Table 6: Mean APACHE 2 Score and RDW

Non-survivors had significantly higher RDW and higher APACHE 2 Score compared to survivors, with highly significant p-values (<0.001 for RDW, 0.02 for APACHE 2).

Table 7 Inflammatory Markers (CRP) in Relation to APACHE 2 and RDW

Patients with APACHE II scores ≥ 25 and RDW ≥ 16.5% show significantly elevated CRP levels, indicating a strong association between systemic inflammation and disease severity. The statistically significant p-value (0.001) highlights CRP’s role as a reliable marker of inflammation in critically ill patients. Elevated CRP levels suggest a heightened inflammatory response, which may correlate with a poorer prognosis.

Table 8 Logistic Regression Analysis of indicators of Sepsis (n=70)

SOFA, APACHE, and RDW scores were all significantly associated with mortality risk. SOFA scores >3, APACHE scores >25, and RDW ≥16.5, were strong indicators of increased risk for multiple organ dysfunction syndrome (MODS) and mortality, as indicated by the highly significant p-values.

The majority of patients in this study fall within the 41-50 years age group (30%), followed by the 31-40 years (23%) and 51-60 years age group (20%). This trend is consistent with previous studies, which have demonstrated that middle-aged and elderly individuals are more prone to sepsis due to immunosenescence and the presence of comorbidities. A study by Naik Sm et al. (2022)⁹ showed that the risk of sepsis increases with age, especially in individuals over 50, which aligns with the findings in the current study where the mean age is 51.72 ± 17.8 years.

Fever (87.1%) and shortness of breath (70%) were the most common presenting complaints. This is in line with findings by Mahapatra S et al. (2023)¹⁰ , where fever and respiratory symptoms were the most frequently reported symptoms in sepsis patients. These symptoms reflect the systemic inflammatory response and respiratory dysfunction commonly seen in sepsis.

The most frequent systemic finding was tachycardia (81.4%), followed by crackles in the respiratory system (55.7%) and confusion (54.3%). This matches the study by Sharma S et al. (2003)¹¹, which emphasized tachycardia as a key feature of septic shock, with respiratory signs such as crackles being indicative of respiratory failure and confusion representing altered mental status due to sepsis-associated encephalopathy.

The ABG analysis showing a mean pH of 7.2 ± 0.2 indicates metabolic acidosis, a common finding in sepsis as noted in studies like Castro D et al. (2024)¹².

A majority of patients in this study had APACHE 2 scores more than 25, indicating severe sepsis. This is similar to findings in a study by Tian Y et al. (2022)¹³, which demonstrated that higher APACHE 2 scores were predictive of increased mortality in sepsis patients.

Most patients had elevated RDW values (>14%), with 45.7% having RDW > 16.5%, indicating a poor prognosis. Studies such as the one by Wen Y et al. (2010)¹⁴ found that elevated RDW is associated with worse outcomes in sepsis, likely due to underlying inflammation and poor erythropoiesis.

The incidence of multiple organ dysfunction (MOD) was significantly higher in nonsurvivors, which aligns with previous research by Doctor A et al. (2017)¹⁵, indicating that MOD is a key determinant of sepsis mortality.

Non-survivors had significantly higher APACHE 2 scores and RDW values, a finding consistent with the study by Bloria SD et al. (2023)¹⁶, which showed a strong correlation between elevated RDW, APACHE 2 scores, and sepsis mortality. The correlation coefficient (r=0.65) further supports the predictive value of these parameters in determining sepsis outcomes.

Higher APACHE 2 scores in older age groups correlate with higher mortality, a finding similar to that of Edipoglu IS et al. (2019)¹⁷, where age was an independent predictor of worse outcomes in septic patients, with increasing age being associated with higher APACHE 2 scores and increased mortality.

The findings in this study align with previous research, highlighting the importance of early identification and aggressive management in sepsis, especially in older patients and those with higher APACHE 2 scores, hypotension, elevated procalcitonin, creatinine levels, and RDW values.

This study highlights key clinical and demographic factors that influence sepsis outcomes. Advanced age, hypotension, tachycardia, elevated PCT, creatinine, and inflammatory markers were associated with higher mortality. The APACHE 2 score and RDW emerged as critical predictors of sepsis prognosis, with higher values significantly correlating with poor outcomes. Early identification of these risk factors, coupled with timely and aggressive management, is essential to improving survival rates in sepsis patients. Further research should focus on targeted interventions and refining prognostic models to enhance the clinical management of sepsis.

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