Incidence, Bacteria Etiology and Factors Associated with Ventilator Associated Pneumonia Among Patients on Mechanical Ventilator in Intensive Care Units at Tertiary Hospitals, Dar Es Salaam.

Abstract

Ventilator Associated Pneumonia (VAP) refers to a nosocomial pneumonia which develops 48-72 hours after endotracheal intubation. VAP remains the common cause of morbidity, mortality and prolonged is the second most common Health care associated Infections (HAI) in the intensive care units (ICU) stay. Multi-drug resistance bacteria account for major cause of VAP. In developing countries, little information is known on VAP. Therefore, investigating the incidence, bacteria etiology and outcomes of the VAP is important in reducing VAP associated the mortality and morbidity. Methodology: This prospective cohort study was carried out between September 2019 and April 2020 among patients on mechanical ventilator (MV) at the ICU of two tertiary hospitals. All patients with clinical diagnosis of VAP, bronchial secretions were collected for microbiological confirmation of VAP. Quantitative bacterial culture was performed and significant growth was defined as microbiological confirmed VAP. Bacteria were identified by standard bacteriological methods and antimicrobial susceptibility was performed by disk diffusion methods. A study questionnaire was used to collect patient‟s socio-demographic and clinical data. Data were analysed by statistical package for social sciences (SPSS) version. Results: A total of 334 patients were enrolled during a study period, 269 met inclusion criteria and were followed up to the end of the study ,65 patients were excluded in the final analysis as did not meet inclusion criteria.Therefore 269 were followed up and included in the final analysis. The median time of mechanical ventilation was 12 IQR[5-19]. The incidence rate of VAP was 40.1/1000 ventilation days.The most common etiology of VAP was P.aeruginosa (23.4%) followed by K.pneumoniae (19.8%) among the gram negative bacilli , S.aureus (19.1%) was the the only gram positive bacteria isolated. Multi-drug resistance bacteria accounted for 70.07% of isolates causing VAP. Antibiotic use in the past 6 months [adjusted odds ratio(aOR) 6.02, Confidence interval(CI) 1.81-20.06 and p-value of 0.002], Cigarette smoking[ aOR 3.4,CI 1.22-9.45 and p value 0.019], patients with general surgical conditions [aOR 6.15CI 1.57-24.08 and p value 0.009], neurosurgical conditions [aOR 4.23, CI 1.19 - 14.87 and p value 0.026] and cerebral vascular disease [aOR 6.09, CI 1.60-23.12, p value 0.008] were independently associated with VAP. VAP [aOR 6.43, CI 1.42- 21.23, p value 0.001] and MDR [aOR 5.31, CI 2.12-7.70 p value 0.001] independently predicted mortality among the patients on MV. Conclusion: The incidence VAP in this study is relatively high among the patients admitted in the four major ICUs at Muhimbili National Hospital and Muhimbili Orthopedic Institute for mechanical ventilation. Majority of the Isolate were Gram negative bacteria and MDR. Mortality among the patients with VAP is higher compared non VAP group. However, the mortality is also higher among the patients infected with MDR isolates. Cigarette smoking, having neurosurgical conditions and general surgical conditions significantly associated with VAP. These findings point out to the need for performing culture and sensitivity for patients with VAP and change the current prescription among the patients admitted at the tertiary care hospitals in Dar es Salaam.