Clinical study of ventilator associated pneumonia in a tertiary care centre

Abstract

Background:  Ventilator associated pneumonia (VAP) remains to be the commonest cause of hospital morbidity and mortality in spite of advances in diagnostic techniques and management. VAP refers to bacterial pneumonia developing in patients who have been receiving mechanical ventilation for at least 48 hours. It is the commonest complication associated with mechanical ventilation. The objectives were to know the incidence and outcome of VAP in a tertiary care centre at Indira Gandhi Institute of child health (IGICH) and to identify the probable risk factors for ventilator associated pneumonia (VAP) and to identify the most common pathogenic bacteria causing VAP. Methods: This is a prospective study of children mechanically ventilated in the pediatric intensive care unit of Indira Gandhi Institute of Child Health. Children between the age group of   >1month to <18 years were included in the study. Ventilator associated pneumonia is defined as per the clinical pulmonary infection score given by Pugin et al, patients were monitored with various clinical and laboratory parameters like fever, purulent endotracheal aspirates, pulmonary radiological changes, leukocytosis, arterial blood gas analysis, blood culture and endotracheal tube aspirate grams stain and culture and sensitivity pattern and other relevant investigations. Results:  Out of the seventy five children requiring mechanical ventilation 17 developed VAP giving the incidence of 22.66%. Early onset VAP constituted 41.1% of the cases and the rest is late onset VAP (58.9%). Reintubation of more than 2 times, central venous lines, tracheostomy and prolonged ventilation are the risk factors for VAP. Pseudomonas (6), Klebsiella (8) were the most frequent and significant etiological agents causing VAP. Pseudomonas and Klebsiella are the common organisms in late onset VAP and Staphylococcus aureus (MRSA) (2) and E coli (1) are isolated in early onset VAP. There is no statistically significant difference in mortality between the VAP and Non-VAP cases. VAP prolongs the duration of mechanical ventilation, length of intensive care and the duration of hospital stay compared to the Non VAP cases. The average duration of ventilation in VAP cases is 6.68±4.12 days. The mean duration of PICU care (16.65days) and hospital stay in VAP children is also prolonged (20.53 days) and it is statistically significant. Conclusions:  VAP is an important nosocomial infection in PICU with the incidence of 22.66%. Prolonged ventilation and repeated intubations are the major risk factors. Central venous lines and tracheostomy are the added risk factors for VAP. Judicious use of ventilator support and early weaning will reduce the incidence of VAP. Gram negative organisms are the most common organisms causing VAP. VAP did not influence the mortality but it did prolong the duration of ventilation, intensive care and hospital stay in turn increasing the morbidity.