Ventilator-associated pneumonia: Outcome in pediatric intensive care unit of a tertiary care center

Arti Dhingra; Sonia Bhatt; Rajesh Kashyap

doi:10.4103/JIHS.JIHS_22_20

ORIGINAL ARTICLE

Year : 2021 | Volume : 9 | Issue : 1 | Page : 4-7

Ventilator-associated pneumonia: Outcome in pediatric intensive care unit of a tertiary care center

Arti Dhingra¹, Sonia Bhatt², Rajesh Kashyap³
¹ Department of Pediatrics, SHKM Government Medical College, Nalhar, Haryana, India
² Department of Pediatrics, FH Medical College and Hospital, Agra, Uttar Pradesh, India
³ Department of Pediatrics, K. D. Medical College, Mathura, Uttar Pradesh, India

Date of Submission	25-Jun-2020
Date of Decision	28-Jul-2020
Date of Acceptance	20-Nov-2020
Date of Web Publication	17-Aug-2021

Correspondence Address:
Dr. Arti Dhingra
Department of Pediatrics, SHKM Government Medical College, Nalhar, Haryana
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JIHS.JIHS_22_20

Abstract

Background: The profile and pattern of ventilator-associated pneumonia (VAP) varies among different settings, depending on the definition, the type of hospital or intensive care unit (ICU), the population studied, and the level of antibiotic exposure. Aim: We aimed to study the profile and pattern of VAP among mechanically ventilated children admitted to a pediatric ICU. Methods: Critically ill children aged 1 month to 12 years of age, who received mechanical ventilation and developed VAP, were included in the study. The VAP was diagnosed using the Clinical Pulmonary Infection Score. The Pediatric Index of Mortality 3 (PIM-3) was also calculated. Categorization of diagnosis was done based on PIM-3 guidelines. The mean length of stay duration of mechanical ventilation was also noted down. Results: The incidence of VAP in the present study was 37.78%. PIM-3 was 2.24. The mean length of stay in cases of early VAP was 8.14 days, whereas it was 20.3 days in late VAP. Two important conditions that led to the development of VAP were respiratory conditions (33.33%) and neurological conditions (27.45%). Liver injury and renal injury were noted in 14 (27.5%) and 10 (19.6%) patients. Significant differences were observed in the mean length of stay and in cases of reintubation. The three most common organisms seen were methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter, and Klebsiella along with Pseudomonas, whereas among nonsurvivors, they were Candida, Citrobacter, Enterococcus spp., methicillin-resistant coagulase-negative staphylococci, and Streptococcus. Conclusion: VAP is a common entity among ventilated children. Cases of late VAP face a longer length of stay on mechanical ventilation. Parenteral nutrition and the presence of nasogastric tubing were significantly associated with late-onset VAP as compared to early VAP. Three most common organisms seen were MRSA, Acinetobacter, and Klebsiella along with Pseudomonas.

Keywords: Children, intubation, organisms, ventilator-associated pneumonia

How to cite this article:
Dhingra A, Bhatt S, Kashyap R. Ventilator-associated pneumonia: Outcome in pediatric intensive care unit of a tertiary care center. J Integr Health Sci 2021;9:4-7

How to cite this URL:
Dhingra A, Bhatt S, Kashyap R. Ventilator-associated pneumonia: Outcome in pediatric intensive care unit of a tertiary care center. J Integr Health Sci [serial online] 2021 [cited 2023 Jun 5];9:4-7. Available from: https://www.jihs.in/text.asp?2021/9/1/4/323952

Introduction

Ventilator-associated pneumonia (VAP) is a type of nosocomial pneumonia that usually occurs 48 h or later after the commencement of mechanical ventilation in a hospitalized patient.^[1] VAP is probably the most common hospital-acquired infection (HAI) seen in adult patients admitted to intensive care units (ICUs).^[2],[3] It is the second most common HAI in case of children, accounting for one-fifth of all HAIs in pediatric ICUs (PICUs).^[4]

VAP is associated with high morbidity, mortality, and negative economic implications. The profile and pattern of VAP varies among different settings, depending on the definition, the type of hospital or ICU, the population studied, and the level of antibiotic exposure.^[5],[6] Knowledge regarding VAP in pediatric intensive care setups and their associated risk factors are important for better management. Aggressive surveillance is vital in understanding local factors leading to VAP and the microbiologic milieu of a given unit.^[7]

Microbial organisms recovered have a direct influence on outcome of VAP. On the other hand, the rationale use of antibiotics is crucial as resistant organisms continue to plague ICUs and critically ill patients. The initial empirical therapy can be modified based on the knowledge of local microbiological data, patient characteristics, and sensitivity pattern of expected pathogens at the institution.^[6] Hence, this article aimed to study the profile and pattern of VAP among mechanically ventilated children admitted to a PICU.

Methods

The present hospital-based descriptive study was planned and conducted by the department of pediatrics of a tertiary care teaching hospital in northern India. The total duration of the study was 1 year (August 2017 to July 2018). Children admitted to the PICU during the study period formed the study population. Critically ill children aged 1 month to 12 years of age, who received mechanical ventilation and developed VAP, were included in the study. Newborns, preterm babies, and children intubated for more than 24 h before PICU admission were excluded from this study.

This tertiary care teaching hospital is an institution, which provides state of the art pediatric intensive care services to every stratum of the society. The department of pediatrics follows standard antibiotic policy and management algorithms for clinically or bacteriologically defined pneumonia. This institution especially caters low- to middle-income population and acts as a tertiary referral unit for pediatric medical and surgical cases not only to home district but also the neighboring districts. Thus, this study area provided us a perfect base to conduct the study.

There is no gold standard for the diagnosis of VAP. For the purpose of this study, Johnson's criteria were followed. As per that criteria, the diagnosis of VAP is defined as the occurrence of a new and persistent radiographic infiltrate not otherwise explained, appearing on chest radiograph along with two of the following: body temperature 38.3°C, leukocytosis (≥10.000 white blood cell/ml), and purulent tracheal aspirate.^[8] The VAP was diagnosed using the Clinical Pulmonary Infection Score (CPIS) as per standard protocol.^[9],[10] CPIS >6 was used as diagnostic criteria for VAP. Endotracheal secretions were sampled under strict universal aseptic precautions. Early-onset VAP was defined as VAP occurring within the first 72 h and late-onset VAP was defined as VAP occurring after 72 h after mechanical ventilation, respectively. The Pediatric Index of Mortality 3 (PIM-3) was also calculated. Categorization of diagnosis was done based on PIM-3 guidelines.^[11] The mean length of stay duration of mechanical ventilation was also noted down.

Written informed consent was taken from parents of the children. The study was started after getting clearance from the Institutional Ethics Committee. All the pro forma were manually checked and then data were entered into Microsoft Excel. After the compilation of collected data, the analysis was done using the Statistical Package for the Social Sciences (SPSS), version 21 (IBM, Chicago, Illinois, USA) software. The results were expressed using mean and standard deviation. Chi-square test, Fisher's exact test, and paired t-test were used to test the significance. P < 0.05 was considered statistically significant.

Results

One hundred and thirty-five patients received mechanical ventilation during the study period. Out of them, 37.78% (n = 51) were diagnosed to have VAP. Thus, the incidence of VAP in the present study was 37.78%. The mortality of PICU was around 8%. The median age of the study participants was 1.25 years, i.e., 15 months (minimum 0.14 years–maximum 5 years). Gender wise, 35 (68.6%) were male children, whereas the remaining 16 (31.4%) were female. Twenty-two (43.14%) study participants were <1 year of age. There was no evidence of malnutrition in 23 (45%) children, whereas severe acute malnutrition was detected in 19 (37.3%) study participants. PIM-3 was 2.24. Early VAP was seen in 37 (72.5%) children, whereas the remaining 14 (27.5%) children developed late VAP.

[Table 1] depicts important conditions that led to the development of VAP. These were respiratory conditions (n = 17, 33.33%), neurological conditions (n = 14, 27.45%), cardiovascular conditions (n = 9, 17.64%), hepatic and gastric conditions (n= 8, 15.69%), and hemato-oncology conditions (n = 3, 5.88%).

Table 1: Important conditions that led to the development of ventilator-associated pneumonia

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Thirty-one (60.78%) children were anemic. Thirty-eight study participants (74.5%) were in a state of shock. Liver injury and renal injury were noted in 14 (27.5%) and 10 (19.6%) patients, respectively. Evidence of leukocytosis was seen in 31 (60.8%) study participants. Hyponatremia was noted in 20 (39.2%) children, whereas coagulopathy was seen in 22 (43.1%) patients.

The mean length of stay duration of mechanical ventilation was 9.20 days with a minimum of 2 days and maximum of 48 days. The mean length of stay in cases of early VAP was 8.14 days, whereas it was 20.3 days in late VAP.

Association of selected variables was studied between the two study groups. Significant differences were observed in the mean length of stay and in cases of reintubation. No significant association was noted between the occurrence of early and late VAP with receipt of parenteral nutrition, presence of nasogastric tube, and death of child [Table 2].

Table 2: Association of selected study variables with early and late ventilator-associated pneumonia

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The distribution of organisms causing VAP among survivors and nonsurvivors was also analyzed. The three most common organisms seen were MRSA, Acinetobacter, and Klebsiella along with Pseudomonas. Proportion wise among survivors, Acinetobacter and Pseudomonas followed by MRSA were the most common organisms, whereas among nonsurvivors, they were Candida, Citrobacter, Enterococcus spp., methicillin-resistant coagulase-negative staphylococci, and Streptococcus [Table 3].

Table 3: Organism-wise distribution of ventilator-associated pneumonia among survivors and nonsurvivors

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Discussion

VAP is a very common challenge faced by medical fraternity in modern PICUs with a wide variation of incidence rates at different places due to a variety of factors such as different diagnostic criteria, variable sensitivity and specificity of the available diagnostic tests, lack of gold standard test for diagnosis of VAP, large spectrum of organisms causing VAP, presence or absence of an antibiotic policy and maintenance of various equipment (warmers and ventilator machines), and differences in the age groups of study participants (neonates, infants, and children) in various studies.

In our study, we observed the incidence of VAP as 37.78%. Our findings agree with two studies conducted in India that reported the incidence of VAP in children to be 33.3%^[12] and 45.4%.^[13] Other pediatric studies reported incidence ranging from 30% to 46.4%.^[14] The incidence of VAP was seen higher than certain Indian studies. It could be due to the fact that being an apex regional referral center, many children with critical conditions probably due to financial reasons might have contributed to incidence in little higher range.

The incidence of VAP differs greatly based on setting and location in critically ill children in PICU.^[15] Another Indian study observed that VAP developed in 36.2% of children requiring mechanical ventilation in India, which is compatible with the present study incidence.^[16] An Egyptian investigation on infection rates in the PICUs in a number of hospitals has shown that the overall rate of HAIs was 24.5% and that of VAP was 31.8/1000 ventilator days.^[17] A Spanish multicenter study on nosocomial infections reported a very low incidence of VAP (1.3%) among children undergoing mechanical ventilation in PICU.^[18]

In this study, we observe significant differences in the mean length of stay and in cases of reintubation. Various studies^[19],[20] have shown that the risk for the development of VAP was 1.2–2 times higher for prolonged ventilation >3 days, 3–13 times higher for tube feeding with large-volume aspiration, 5–9.5 times higher for reintubation, 2.5–77.5 times higher for the use of sedatives, 3.9 times higher for decreased level of consciousness, and 2.4 times higher for genetic syndromes. Enteral nutrition is preferred over parenteral nutrition because of less risk for infectious complications related to the use of central venous catheters. However, the use of gastric feeding tubes leads to an increased risk for gastroesophageal reflux and aspiration, leading to the development of VAP.

No significant association was noted between the occurrence of early and late VAP with receipt of parenteral nutrition, presence of nasogastric tube, and death of child. APACHE II score was utilized by another study from Pakistan to evaluate the condition of patients at admission, and they found that patients with VAP had higher scores and hence higher mortality rate.^[19],[20] A prospective longitudinal study would have provided better information on the role of PIM-3 in predicting mortality in VAP.

We observed that the three most common organisms seen were MRSA, Acinetobacter, and Klebsiella along with Pseudomonas. A meta-analysis^[15] of pediatric VAP studies found a predominance of Gram-negative organisms in Asia, and the most common pathogens were Pseudomonas spp., Acinetobacter spp., and Enterobacteriaceae spp. Patra et al. demonstrated VAP in 76% of patients with hospital-acquired pneumonia, and this represented the most frequent nosocomial infection in ICUs (80%) with an overall mortality of nosocomial pneumonia reaching 60%; all of these were secondary to Gram-negative infections with Pseudomonas contributing to 57.1% of deaths, followed by Klebsiella, Escherichia coli, and Acinetobacter.^[5],[21]

Conclusion

Almost one-third of ventilated children develop VAP. Cases of late VAP face a longer length of stay on mechanical ventilation. Parenteral nutrition and the presence of nasogastric tubing were significantly associated with late-onset VAP as compared to early VAP. The three most common organisms seen were MRSA, Acinetobacter, and Klebsiella along with Pseudomonas. This study thus emphasizes the need for identifying and minimizing the risk factors and proper choice of antibiotics as per sensitivity would improve outcome.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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