SOFA Score with Serum Procalcitonin Versus SOFA Score with Neutrophil/lymphocyte Ratio in Predicting Sepsis and Clinical Outcomes in I.C.U.

Sepsis provokes a dysregulated host response to infection that leads to acute organ dysfunction. The subsequent Septic shock, which includes an underlying circulatory and cellular imbalance increases the mortality. Septic shock manifests as persistent hypotension requiring vasopressors to maintain a mean arterial pressure of 65 mm Hg or higher and a serum lactate level greater than 2 mmol/L (18 mg/dL) in the absence of hypovolemia.

Sequential Organ Failure Assessment score (SOFA) has become extensively used and one of the gold standard tests in assessing the patient's status during intensive care unit (ICU) stay and predicting the clinical outcomes of the patients, however, poor sensitivity of SOFA score is a major limitation that excludes its use as a screening tool for early sepsis, the stage in which treatment is most effective. Blood culture is a well-established diagnostic test for sepsis, however, has limitations e.g. prolonged incubation time and probability of false-negative results.

Procalcitonin (PCL) has been studied as a sepsis biomarker, to help with sepsis diagnosis and to guide the initiation and cessation of antibiotics. Procalcitonin strongly correlates with the extent and severity of bacterial infections, better indicator of illness severity than CRP, and also, provides a quick result compared to blood cultures. Procalcitonin use may be hindered by availability and the cost in a limited resources environment, However, The neutrophil-to-lymphocyte ratio (NLR) is a readily available marker. The neutrophil-to-lymphocyte ratio (NLR) is an indicator of systemic inflammation based on complete blood count values. In general, blood neutrophil count increases with the progress of the inflammatory disease, NLR is more reliable when predicting patient survival than either neutrophil count or lymphocyte count alone.

Endogenous cortisol and catecholamines increase the neutrophil count while simultaneously decreasing the lymphocyte count so it may be major drivers of the NLR. Also, cytokines and other hormones are likely to be involved. So NLR is not solely an indication of infection or inflammation. Any cause of physiologic stress may increase the NLR (e.g. hypovolemic shock). NLR increases rapidly following acute physiologic stress (\<6 hours). This prompt response time may make NLR a better reflection of acute stress. Interpretation of NLR level is as follows: A normal NLR is roughly 1-3, An NLR of 6-9 suggests mild stress and Critically ill patients will often have an NLR of \~9 or higher (occasionally reaching values close to 100).

This research will test the predictability of combined SOFA score and procalcitonin versus combined SOFA score and NLR for clinical outcomes such as length of ICU stay and mortality.

• 28 days mortality [Time frame: From the day of admission at the ICU and up to 28 days.]
• Antibiotics used [Time frame: From ICU admission to discharge from ICU or death which comes first up to 40 days from admission.]