NEUTROPHIL TO LYMPHOCYTE RATIO AS A MARKER OF OUTCOME IN CRITICALLY ILL CHILDREN ADMITTED TO PAEDIATRIC INTENSIVE CARE UNIT

The PICU is constantly in a fluctuating state depending on the constantly changing

conditions of the critically ill patients being cared for there, while having a high

mortality and morbidity rate. In India, the most common diseases among children

admitted to the Paediatric intensive care unit (PICU) include respiratory infections

(such as pneumonia and bronchiolitis), sepsis, dengue fever, malaria and Acute

Respiratory Distress Syndrome(ARDS). Other common conditions include, injuries

from accidents, poisoning and neurological disorders. In addition, malnutrition and

undernutrition are also prevalent among critically ill children in India and contribute to

poor outcomes. Before severe sepsis develops into septic shock, early identification

of patients who may progress to severe sepsis and initiation of appropriate antibiotic

therapy and efficient fluid resuscitation may reduce mortality(1) Due to the high

burden of infectious diseases in India, PICUs often have a high proportion of patients

with infectious etiologies. It is said that the art of medicine is in

diagnosing/recognising a condition before its onset. This statement only emphasizes

the special need of patients to have predictability markers which can help predict the

patient’s outcome as early and as accurately as possible. Procalcitonin (PCT) and

C‐reactive protein (CRP) have been used in evaluation of the severity of an episode

of sepsis along with patient therapeutic responses and guide duration of therapy in

critically ill patients. (2) However, due to their nonspecific character and insufficient

predictive value for the individual, urgent identification of a more robust biomarker is

essential. An ideal prognostic score should be easy, comprehensible, minimally

invasive. The neutrophils and the lymphocytes are the key cellular component of the

human host defense system.The neutrophil to lymphocyte ratio (NLR) is an

emerging marker of inflammation in paediatric population that is used to assess the

severity of disease in critically ill children. A higher NLR may indicate a severe

inflammatory progression in the patient (3). Although a number of clinical biomarkers

in critically ill have been extensively studied, few have been examined in paediatric

population (4) As a biomarker, the predictive and prognostic value of NLR in

pulmonary and cardiovascular disease, as well as cancer, has been studied

(5)..While normal values vary depending on the age, sex and other factors, generally

a NLR greater than 3 in paediatric population is considered elevated (6) .Although

neutrophil-to-lymphocyte ratio (NLR) has been extensively studied in several

diseases in adults , its role in paediatric population remains unclear. NLR has been

studied as a prognostic marker for Sepsis in few paediatric studies but its role in

other diseases has not been studied till now .Our study aimed to assess the

predictive significance of NLR as a parameter for outcome in all critically ill patients

in the paediatric intensive care unit (PICU). However, it is important to note that the

NLR is not specific to any one disease or condition, and an elevated NLR can be

seen in a variety of illnesses including infections, malignancies, and inflammatory

disorders and hence can be used as a predictive marker for all critically ill children

admitted in PICU.