Ventilator-associated pneumonia (VAP) is a type of hospital-acquired pneumonia that develops in patients who have been mechanically ventilated for at least 48 hours via an endotracheal tube or tracheostomy. It is among the most common and serious infections in intensive care units (ICUs), leading to prolonged mechanical ventilation, extended ICU stay, increased antibiotic exposure, and significant healthcare burden. The incidence of VAP varies widely depending on diagnostic criteria, ICU practices, and patient populations. A meta-analysis of 17 studies involving 6,222 patients reported a pooled VAP incidence of approximately 30% (95% CI: 24–37%) [1]. Multiple risk factors contribute to the development of VAP, involving both patient-related and treatment-related variables. A recent systematic review and meta-analysis of 16,731 ICU patients identified male gender, prior antibiotic exposure, re-intubation, tracheostomy, H₂-blocker use, enteral feeding, nasogastric tube placement, neuromuscular blocking agents, trauma, impaired consciousness at admission, chronic obstructive pulmonary disease (COPD), and longer duration of mechanical ventilation as significant contributors to VAP risk [2]. The pathogenesis of VAP is multifactorial. Microaspiration of contaminated secretions past the endotracheal tube cuff is considered a central mechanism. Biofilm formation on the endotracheal tube allows colonization by pathogenic microorganisms. Additionally, critically ill patients exhibit impaired host defenses, making them more susceptible to pulmonary infections and reducing their ability to clear invading organisms. Diagnosis of VAP remains challenging because clinical signs such as fever, leukocytosis, or increased secretions, as well as radiographic infiltrates, can be nonspecific in ventilated patients. Furthermore, microbiological confirmation often takes time and may be confounded by colonization. Current research is exploring biomarkers, quantitative cultures, and diagnostic scoring systems to improve diagnostic accuracy. The impact of VAP on clinical outcomes is considerable. A meta-analysis of patient-level data from 24 randomized trials estimated that the attributable mortality of VAP is approximately 13%, with higher mortality seen in surgical patients and those with intermediate illness severity [3]. Another observational cohort study of 2,897 mechanically ventilated patients showed mortality rates as high as 38% among VAP cases compared with non-VAP patients [4]. Because VAP contributes heavily to morbidity, mortality, and cost, its prevention is a major focus of ICU quality improvement initiatives. Evidence-based prevention strategies include semirecumbent positioning, subglottic secretion drainage, minimization of sedation, oral hygiene protocols, and strict antibiotic stewardship. However, adherence remains variable, and institution-specific data are essential for targeted prevention. Given these considerations, it is crucial to assess the burden, risk factors, microbiological profile, and outcomes of VAP within specific clinical environments. Therefore, the present retrospective study conducted in the Intensive Care Unit of the Super-Speciality Hospital, Government Medical College Srinagar aims to evaluate the demographic and clinical characteristics of VAP, identify risk factors prevalent in our setting, and compare our findings with global evidence to help inform improved prevention and management strategies.

Study design This study was conducted as a retrospective observational analysis in the Intensive Care Unit (ICU) of the Super-Speciality Hospital, Government Medical College Srinagar. The study aimed to evaluate the clinical profile, risk factors, microbiological characteristics, complications, and outcomes of patients who developed ventilator-associated pneumonia during the study period. Study period The study covered a continuous period of 12 months, from January 2023 to December 2023. Study setting The ICU is a tertiary-level, multidisciplinary critical care unit with 24 functional beds. It caters to critically ill patients from departments including emergency medicine, internal medicine, neurology, neurosurgery, cardiology, pulmonology, and trauma care. Standard protocols for mechanical ventilation, infection prevention, and VAP-prevention bundles (such as semirecumbent positioning, oral care, hand hygiene, and sedation minimization) are followed routinely. Study population All adult patients aged 18 years and above who were initiated on invasive mechanical ventilation and remained ventilated for at least 48 hours during the study period were eligible for inclusion. Inclusion criteria 1. Patients aged ≥18 years 2. Patients who received invasive mechanical ventilation for ≥48 hours 3. Patients with complete medical records available for review Exclusion criteria 1. Patients with evidence of pneumonia prior to intubation 2. Patients who developed pneumonia within the first 48 hours of ventilation 3. Patients transferred from another hospital with pre-existing pneumonia 4. Records with missing essential clinical or microbiological data Sample size A total of 271 patients met the inclusion criteria. Out of these, 36 patients developed ventilator-associated pneumonia during the study period. Data collection Data were collected retrospectively from ICU electronic medical records, admission registers, nursing charts, laboratory documentation, microbiology reports, and radiological archives. A structured data extraction sheet was used to ensure uniformity. The following variables were documented: * Demographic variables: age, sex * Clinical characteristics: primary diagnosis, comorbidities, reason for ICU admission * Severity scores: APACHE II score at admission * Ventilation-related data: total duration of mechanical ventilation, re-intubation, tracheostomy, sedation practices, neuromuscular blocker use * Nutrition: enteral feeding initiation and route * Risk factors: prior antibiotic exposure, aspiration risk, supine positioning episodes * VAP diagnostic data: clinical signs, radiological findings, specimen types, microbiological culture results * Treatment details: empirical and targeted antibiotic therapy * Complications: septic shock, ARDS, acute kidney injury, multi-organ dysfunction * Outcome measures: length of ICU stay, hospital stay, duration of ventilation, survival or mortality Diagnostic criteria for VAP Ventilator-associated pneumonia was diagnosed when all of the following criteria were met: 1. New or progressive pulmonary infiltrates on chest radiograph 2. At least two of the following clinical findings: * Fever ≥38°C * Leukocytosis or leukopenia * Increased or purulent tracheobronchial secretions 3. Positive microbiological growth from one of the following: * Endotracheal aspirate (≥10⁵ CFU/mL) * Bronchoalveolar lavage (≥10⁴ CFU/mL) Microbiological methods * Endotracheal aspirates and bronchoalveolar lavage specimens were collected using sterile techniques. * Samples were processed immediately in the microbiology laboratory. * Standard culture methods were used to identify organisms. * Antimicrobial susceptibility testing was performed using automated systems and standard guidelines. Statistical analysis Data were compiled using Microsoft Excel and analysed using SPSS version 25. * Continuous variables were presented as mean ± standard deviation. * Categorical variables were expressed as percentages. * Comparison between VAP and non-VAP groups was performed using: * Independent t-test for continuous variables * Chi-square test for categorical variables * Multivariate logistic regression was used to identify independent predictors of VAP and mortality. * A p-value <0.05 was considered statistically significant. Ethical considerations The study protocol was approved by the Institutional Ethics Committee of Government Medical College Srinagar. As the study was retrospective and used anonymised data, informed consent was waived.

A total of 271 mechanically ventilated adult patients were included in the study. Among them, 36 patients (13.2 percent) developed ventilator-associated pneumonia (VAP) during the study period. The demographic profile of the study population showed that VAP occurred more frequently in older patients and in males. The mean age of patients who developed VAP was higher compared to those who did not develop VAP. The presence of comorbidities such as diabetes mellitus, hypertension, COPD, and chronic kidney disease was also more common among VAP cases. Table 1. Demographic and baseline characteristics of the study population (n = 271) Parameter VAP (n = 36) Non-VAP (n = 235) Total (n = 271) Mean age (years) 61.4 ± 13.2 54.1 ± 15.8 55.1 ± 15.4 Age > 60 years 22 (61.1 percent) 88 (37.4 percent) 110 (40.5 percent) Male sex 24 (66.7 percent) 142 (60.4 percent) 166 (61.2 percent) Diabetes mellitus 14 (38.8 percent) 54 (22.9 percent) 68 (25.1 percent) Hypertension 18 (50 percent) 84 (35.7 percent) 102 (37.6 percent) COPD 10 (27.7 percent) 29 (12.3 percent) 39 (14.3 percent) Chronic kidney disease 6 (16.6 percent) 21 (8.9 percent) 27 (9.9 percent) Mean APACHE II score 21.3 ± 6.4 17.4 ± 5.7 18.0 ± 6.1 Patients who developed VAP had a significantly longer duration of mechanical ventilation. The proportion of patients requiring re-intubation or tracheostomy was also markedly higher among VAP cases. Sedation and neuromuscular blocking agents were used more frequently in the VAP group. Most VAP cases exhibited classical clinical and laboratory findings. Fever, leukocytosis, and purulent secretions were significantly more frequent among VAP patients. Radiological infiltrates were present in all VAP cases at the time of diagnosis. Gram-negative bacteria were the predominant pathogens in VAP cases, with Acinetobacterbaumannii emerging as the most frequently isolated organism, followed by Klebsiellapneumoniae and Pseudomonas aeruginosa. A smaller proportion of cases were caused by gram-positive organisms. Table 2. Ventilation-related risk factors Parameter VAP (n = 36) Non-VAP (n = 235) Mean duration of ventilation (days) 12.6 ± 4.8 6.9 ± 3.5 Re-intubation required 9 (25 percent) 14 (5.9 percent) Tracheostomy performed 11 (30.5 percent) 23 (9.7 percent) Sedation > 72 hours 26 (72.2 percent) 102 (43.4 percent) Neuromuscular blocking agents | 14 (38.8 percent) | 53 (22.5 percent) 14 (38.8 percent) 53 (22.5 percent) Supine position > 24 hours 12 (33.3 percent) 38 (16.1 percent) Table 3. Clinical and laboratory findings at VAP diagnosis Parameter VAP (n = 36) Fever (>38°C) 30 (83.3 percent) Leukocytosis (>12,000 cells/mm³) 26 (72.2 percent) Purulent secretions 32 (88.8 percent) New or progressive infiltrates 36 (100 percent) Elevated CRP (>50 mg/L) 28 (77.7 percent) Septic shock at diagnosis 9 (25 percent) Table 4. Microbiological isolates from VAP cases (n = 36) Organism Number of isolates Percentage Acinetobacterbaumannii | 14 38.8 percent Klebsiellapneumoniae 9 25 percent Pseudomonas aeruginosa 6 16.6 percent Staphylococcus aureus (MRSA) 4 11.1 percent Escherichia coli 2 5.5 percent Mixed infections 1 2.7 percent The outcomes of patients with VAP were notably worse compared to non-VAP patients. Duration of mechanical ventilation and ICU stay were significantly prolonged. Mortality among VAP patients was higher compared to non-VAP patients. Table 5. Patient outcomes Outcome parameter VAP (n = 36) Non-VAP (n = 235) Mean ICU stay (days) 18.2 ± 6.9 10.7 ± 4.1 Mean hospital stay (days) 25.4 ± 8.6 17.5 ± 6.2 Septic shock during ICU stay 12 (33.3 percent) 26 (11 percent) Acute kidney injury 10 (27.7 percent) 38 (16.1 percent) ARDS 7 (19.4 percent) 21 (8.9 percent) Mortality 14 (38.8 percent) 54 (22.9 percent) Summary 1. The incidence of VAP was 13.2 percent. 2. Older age, male sex, and comorbidities such as COPD and diabetes were more common among VAP cases. 3. Prolonged ventilation, re-intubation, and heavy sedation were major contributors. 4. Gram-negative organisms, especially Acinetobacterbaumannii, were the leading pathogens. 5. VAP was associated with significantly higher ICU stay, hospital stay, complications, and mortality (38.8 percent). Bar graph: Microbiological Profile of VAP Cases. Bar graph 2:Outcomes Comparison: VAP vs Non- VAP.

In our retrospective cohort of mechanically ventilated patients in the ICU of the Super-Speciality Hospital, Government Medical College Srinagar, ventilator-associated pneumonia (VAP) occurred in 13.2 percent of cases, which is broadly consistent with previously reported rates. Meta-analytic data suggest a pooled incidence of around 30 percent in some ICU populations [5]. This variation between our study and global estimates may reflect differences in patient mix, local preventive practices, and diagnostic thresholds. We observed that longer duration of mechanical ventilation, re-intubation, tracheostomy, and heavy sedation were significantly associated with VAP in our cohort. These factors align closely with those identified in large meta-analyses: male gender, re-intubation, tracheostomy, use of H2-blockers, prior antibiotic exposure, enteral feeding, neuromuscular blockade, and prolonged intubation were all associated with higher risk of VAP [6]. The consistency with published data underscores that both patient-related and treatment-related risk mechanisms remain highly relevant in our setting. Gram-negative bacteria dominated the microbial profile in our VAP cases, with Acinetobacterbaumannii being the most frequent isolate, followed by Klebsiellapneumoniae and Pseudomonas aeruginosa. This pattern mirrors data from other studies of VAP, where Acinetobacter in particular has been shown to carry a high mortality. For example, a retrospective ICU study in Tunisia found that A. BaumanniiVAP was associated with a mortality of over 60 percent; hemodynamic instability (septic shock) at onset was an independent predictor of poor outcome [7]. The high proportion of multidrug-resistant Gram-negative isolates in our cohort suggests that empirical antimicrobial strategies and stewardship policies must be carefully tailored, and infection control practices strengthened to prevent colonisation and transmission. In our patients, VAP was linked to prolonged ICU stay, extended hospitalisation, higher rates of septic shock, acute kidney injury, ARDS, and a mortality rate of 38.8 percent. These adverse outcomes are consistent with the known clinical impact of VAP. A large meta-analysis found that VAP was associated with significantly longer ICU stay, mechanical ventilation, and hospital stay [6]. Importantly, while some studies ascribe a substantial attributable mortality to VAP, our findings must be interpreted cautiously in light of mixed evidence. In a well-cited meta-analysis of 44 studies, the presence of VAP was associated with nearly double the odds of death in the ICU (OR ~1.96), but this association was attenuated in studies where initial antimicrobial therapy was appropriate [8]. This suggests that timely, effective empirical therapy may mitigate the mortality risk attributable to VAP. Preventive strategies remain the cornerstone for reducing VAP burden. A landmark meta-analysis demonstrated that use of endotracheal tubes with subglottic secretion drainage reduces VAP incidence by approximately 45 percent (risk ratio ~0.55) and may reduce duration of ventilation and ICU stay, although mortality benefits were not statistically significant [9]. These findings support the reinforcement of preventive bundles in our ICU, including consistent use of subglottic drainage, head-of-bed elevation, sedation protocols, oral hygiene, and antibiotic stewardship. Given the high prevalence of multidrug-resistant organisms in our VAP cases and their association with worse outcomes, our data advocate for the formulation of local empirical antibiotic guidelines informed by our unit’s microbiological profile. Early de-escalation based on culture results, together with strict infection control measures, could help limit the impact of resistant pathogens. There are several limitations to our study. First, being retrospective, there is potential for missing or incomplete data (clinical, microbiological, radiological), which could bias risk factor associations. Second, our diagnostic criteria for VAP, while in line with standard definitions, rely on culture thresholds that may not distinguish colonisation from infection. Third, we did not perform molecular typing or resistance-mechanism studies of isolates, limiting insights into strain-level epidemiology. Finally, as a single-center study, our findings might not generalise to other ICUs with different patient profiles or care practices. Future work should include prospective surveillance, incorporating more advanced diagnostics (e.g., molecular diagnostics, biomarkers) to improve the accuracy of VAP diagnosis. Implementation of machine-learning-based predictive models could help identify at-risk patients earlier, allowing targeted preventive interventions. In addition, continuous monitoring of local antimicrobial resistance trends and clinical outcomes is required to refine empirical treatment protocols and stewardship efforts.

Ventilator-associated pneumonia remains a significant challenge in critical care medicine, particularly in resource-limited, high-burden environments such as tertiary-care ICUs. In our retrospective analysis conducted in the Super-Speciality Hospital, Government Medical College Srinagar, VAP constituted a considerable proportion of infections among mechanically ventilated patients and was associated with increased morbidity, prolonged mechanical ventilation, extended ICU and hospital stay, and a substantially higher mortality rate. The demographic and clinical characteristics observed in our cohort, along with the predominance of multidrug-resistant Gram-negative pathogens, underscore the persistent threat posed by VAP and the importance of coordinated infection prevention and control strategies. Key modifiable factors contributing to VAP, such as prolonged ventilation, re-intubation, heavy sedation, and tracheostomy, emphasize the need for vigilant monitoring and adherence to evidence-based ventilatory practices. Our findings reinforce the necessity for robust VAP prevention bundles, timely and appropriate empirical antimicrobial therapy, and the strengthening of antimicrobial stewardship programs. Additionally, institution-specific microbiological surveillance is essential for guiding empiric antibiotic choices and curbing resistance trends. Although the retrospective design imposes inherent limitations, this study provides valuable insight into the epidemiological and clinical profile of VAP within our institution. Future prospective studies employing advanced diagnostic modalities, standardized protocols, and continuous outcome monitoring will be critical to improving care delivery and reducing the burden of ventilator-associated complications. This work highlights the pressing need to enhance preventive practices, refine early detection strategies, and promote judicious antimicrobial use, ultimately aiming to reduce VAP incidence and improve overall patient outcomes in the ICU. Conflict of interest: Nil Funding: Nil

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