Effectiveness Of Serum Procalcitonin And Serial Levels of C-Reactive Protein Versus Blood Culture In Early Diagnosis of Neonatal Sepsis

Abstract

INTRODUCTION: Neonatal sepsis is a clinical syndrome characterized by signs and symptoms of infection with or without accompanying bacteremia in the first month of life. Rapid and accurate diagnosis of neonatal sepsis is often Cumbersome in routine clinical practice because of its non specific clinical presentation. Although Blood culture is warranted as gold standard there is a substantial time delay as the blood culture result is ready only after 24 to 72 hours. Therefore, using rapid diagnostic methods including laboratory markers could be beneficial for the diagnosis of neonatal sepsis. AIM AND OBJECTIVES:  To know the Effectiveness of serum Procalcitonin , C-Reactive Protein and heamatological parameters versus Blood culture in early diagnosis of Neonatal Sepsis in Neonatal Intensive Care Unit. MATERIALS AND METHODS: Study area: Neonatal intensive care unit at KLE’s Dr. Prabhakar Kore Hospital, Belagavi. Study design: A cross sectional study. Study period: January 2017 to December 2017 over a period of 1 year. Study participants: Neonates with signs suggestive of sepsis admitted to Neonatal intensive care unit at KLE’s Dr. Prabhakar Kore Hospital,Belagavi. Sample size: Sample size is calculated by using the formula : (Za)2 x sensitivity x (100-sensitivity) (relative error) 2 x prevalance where, : Z a (constant) = 1.96 @ 2 S = Sensitivity = 81 d = relative error = 5% p = prevalence = 7% = (2)2 x 81x(100-81)/(5)2 x7 = 4x81x19/25x7 = 6156/175 = 35.17 @ 36. Sample size:36. Sampling procedure: Universal sampling method. Inclusion criteria: Neonates who are going to be started on antibiotics with : a) Neonatal risk factors like Low birth weight, Preterm, Prematurity or Twins presenting with any of the following clinical signs: • Convulsions • Respiratory rate >60 breaths/min . • Severe chest indrawing . • Nasal flaring. • Grunting . • Buldging /depressed fontanelle. • Discharge draining from the ear. • Redness around umbilicus extending to the skin. • Temperature .37.7˚C (or feels hot) or ,35.5˚C(or feels cold). • Lethargic or unconscious(not aroused by minimal stimulus). • Reduced movements. • Not able to feed (not able to sustain suck). • Not attaching to the breast. • No suckling at all. • Crepitations. • Cyanosis and • Reduced digital capillary refill time. Any of the signs listed above implies high suspicion of serious bacterial infection. OR WITH b) Maternal risk factors : • Premature rupture of membranes. • Prolonged labour( sum of 1st and 2nd stage of labour is >24 hours). • Rupture of membranes(>24 hours). • Maternal fever with evidence of bacterial infection within two weeks prior to delivery. • Foul smelling or meconium stained liquor. • Urinary tract infection. • Caesarean section. • Single unclean or more than 3 sterile vaginal examinations. • Twin pregnancy. • Invitro conception. • Preclaamsia. • Gestational diabetes mellitus. • Cervical stitch insitu. Exclusion criteria: a) Neonates who had Birth asphyxia, Aspiration syndrome. b) Laboratory findings which are suggestive of Inborn errors of metabolism c) Neonates with Congenital anamolies . d) Referred cases already treated with antibiotics. Methodology: • Written consent was taken from the Mother. • 1-2ml of venous blood was collected following aseptic precautions by a trained staff prior to the administration of antibiotics for the sepsis screening, which included Blood culture, Haematological parameters, serum Procalcitonin level and serum C-Reactive Protein level.A Second Blood sample of was collecte to determine the serial levels of C-Reactive Protein which is done 72 hours apart after the administration of Antibiotics. • The Sepsis work up included: a) Haematological parameters. b) Blood culture to isolate the organism. c) Serum Procalcitonin Level: By Quantitative method using B.R.A.H.M.S PCT kit using cobas e analysers. d) Serum CRP levels :By Latex Serology test using Cobas c analysers. Statistical Analysis: To evaluate the Effectiveness of serum Procalcotonin levels and serial levels of serum C-Reactive Protein against Blood culture and Haematological parameters, Sensitivity analysis was done. Indices like Sensitivity, Specificity, Positive Predictive Value and Negative Predictive Value was competed for each of the screening procedures. RESULTS: The screening tests applied in the present study showed the following results: a) PCT: Sensitivity-65.59% Specificity-53.84% Positive Predictive Value-72.72% Negative Predictive Value-50% b) 1ST CRP: Sensitivity-50% Specificity-92.30% Positive Predictive Value-92.30% Negative Predictive Value-52.17% c) Haemoglobin percentage: Sensitivity-26.06% Specificity-84.16% Positive Predictive Value75% Negative Predictive Value-39.28% d) Total WBC counts : Sensitivity-61.11% Specificity-53.84% Positive Predictive Value-64.70% Negative Predictive Value- 36.84% e) Platelet counts : Sensitivity-47.05% Specificity-69.25% Positive Predictive Value-66.66% Negative Predictive Value-37.5% CONCLUSION: PCT showed the highest sensitivity followed by total WBC counts and CRP.CRP showed highest specificity and positive predictive value among all other markers. But neither of these markers are 100% sensitive nor 100% specific to be relied as a sole marker. We would like to conclude that blood culture even though considered as gold standard it is time consuming and at times gives false negative results. The greatest predictability can be achieved by the combination of total WBC counts, CRP and PCT rather than a single biomarker. So it is high time to initiate rigorous steps to expand the continuing search for a definitive diagnostic biomarker using multi-centric studies based on a harmonized protocol.