European Journal of Cardiovascular Medicine

Ventilator associated pneumonia (VAP) is defined as nosocomial pneumonia in mechanically ventilated patients which develops more than 48 hours after initiation of mechanical ventilation (MV). VAP is divided into early onset VAP which occurs within 5 days of mechanical ventilation and late onset VAP which develops five or more days after initiation of mechanical ventilation. (1)

VAP arises when there is bacterial invasion of the pulmonary parenchyma in a patient receiving mechanical ventilation. Inoculation of the formerly sterile lower respiratory tract typically arises from aspiration of secretions, colonization of the aerodigestive tract or use of contaminated equipment or medications. Risk factors for VAP include prolonged intubation, enteral feeding, witnessed aspiration, paralytic agents, underlying illness and extremes of age. (2)

The risk factors for VAP can be divided into three categories: host related, device related and personnel related. Host related risk factors include preexisting conditions such as immunosuppression, chronic obstructive lung disease and acute respiratory distress syndrome. Other host-related factors include patient’s body positioning, level of consciousness, number of intubations and medications including sedative agents and antibiotics. (3)

The incidence of VAP increases with the duration of mechanical ventilation. VAP may account for up to 60% of all healthcare associated infections out of the total. The VAP increases the length of ICU stay of a patient by around 28% and doubles the risk of mortality as compared with patients without VAP. (4,5)

The prevalence of multidrug‑resistant (MDR) organisms as a cause of VAP is also becoming a major health concern. Gram‑negative bacteria such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Acinetobacter spp. and Gram‑positive bacteria such as Staphylococcus aureus are the common causative pathogens of VAP. Delay in starting appropriate antibiotic therapy can increase the mortality associated with VAP and thus therapy should be started immediately. (6,7)

The mortality rate for VAP ranges between 27 and 76% Pseudomonas and Acinetobacter pneumonia is associated with higher mortality rates than those associated with other organism. Studies have consistently shown a delay in starting appropriate and adequately dosed antibiotics therapy increased the mortality rate. (8)

Aims & Objective:

To assess risk factor and clinico – microbiological profile of VAP patients.

Inclusion criteria- Patients of either sex, age group of 14 to 90 Years with sample size of 130 admitted to the ICU of Medicine (MICU), Head Injury ICU(HICU) and Respiratory Medicine ICU (RICU) developing pneumonia after 48 hours of initiation of invasive Mechanical Ventilation /even after extubation.

Exclusion criteria-Those patients developing pneumonia within 48 hours of Invasive mechanical ventilation were excluded from study.

Study type- This is a hospital based cross-sectional study.

Place of study- ICU of Medicine (MICU), Head Injury ICU and ICU of Respiratory medicine (RICU) at University of Medical Sciences, Saifai, Etawah.

Duration of study- June 2021 to December 2022.

In all the patients complete hemogram , renal and liver function test, serum electrolyte (Na, K, Ca), random blood sugar, Blood sugar (Fasting and Post prandial) with viral marker testing (HIV, HBsAg, HCV) were done. In all patient sample were collected from endotracheal tube (ET) as ET Aspirate of about 5-7 ml. and were sent for Gram staining, Z-N Staining, Cartridge based nucleic acid amplification test (CBNAAT) for Mycobacterium tuberculosis detection by GeneXpert® using cartridge MTB/RIF(CEPHEID), Mycobacterial culture and KOH mount. All samples were cultured on MacConkey agar, Blood agar, Chocolate agar and Saboraud’s Dextrose agar for isolation of bacteria and fungi followed by drug sensitivity in Department of Microbiology, UPUMS, Saifai, Etawah.

All samples were first stained by Gram’s stain followed by inoculating under aseptic technique on 5% blood agar and MacConkey agar plates and were incubated aerobically at 37℃  overnight.

Data analysis:

The data thus collected was encoded in Microsoft Excel Worksheet and analyzed using SPSS statistical software version 24 (IBM, USA). Proportions, Mean, Standard deviation, Chi-square test, t-test is used for statistical analysis and presentation of data.

A total of 130 study participants with 92(70.8%) males and 38(29.2%) females were evaluated for ventilator associated pneumonia after 48 hours of initiation of mechanical ventilation. We found the following result:

The mean age of study participants was 57.28 ± 15.2 years with a range from 46-60 years. Among all study participants, 26(20%) were below 45 years of age while the rest 104(80%) were above 45 years of age.

In relation to gender the incidence of VAP was more among males (70.8%) than females (29.2%) and in different age groups the incidence of VAP was highest in patients more than 45 years of age (80%).

Among all study participants bacterial growth seen in 114(88%) endotracheal aspirate sample while in 16(12%) sample no growth is seen. Out of 114 bacterial growth 94(72.3%) showed monobacterial growth, 20(15.4%) showed polybacterial growth. Out of all bacterial isolate that take Gram stain 3(2.2%) were gram positive bacteria while 131(97.8%) were gram negative bacteria. Pseudomonas was the most common bacterial isolate from all samples numbering 41(30.6%) out of 134 isolates followed by 34(25.4%) isolate of Escherichia coli and 26(19.4%) isolate of Klebsiella. Citrobacter isolated in 24(17.9%) samples. Proteus isolated in 4(3%) samples. Acinetobacter and Enterococcus both were isolated from 2(1.5%) samples. Staphylococcus isolated in 1(0.7%) sample.

Among all the patients of Ventilator associated pneumonia 52(40%) patients expired while 78 (60%) patients survived. Maximum mortality occurs in age group of 46 to 75 years. female predominance (44.7%) and in smoker 30(57.7%).

Among all the expired patients of ventilator associated pneumonia maximum were associated with obstructive airway disease (COPD/Asthma) (32.7%) followed by Type 2 diabetes mellitus (28.8%), hypertension (15.4%), post tuberculosis sequalae (11.5%), head injury (9.6%).

Out of all expired patients most common isolated organism was Pseudomonas 18(13.8%) followed by Escherichia coli 14(10.7%), Klebsiella 9(6.9%), Citrobacter 2(1.5%),Acinetobacter and Staphylococcus 1(0.76%) each.

Mean duration of hospitalization in expired patients was 10.17±1.897 days while in survived patients mean duration of hospitalization was 9.74±1.767 days.

Maximum patients were in age group of 46-60 years (n=47/130). The risk of VAP increases with advancing age. Among all study participants, 26(20%) were below 45 years of age while the rest 104(80%) were above 45 years of age. Mean age of study participants was 57.28 ± 15.2 years which is similar to previous study done by Deshmukh B et al the mean age of the patients was 54.26+11.6 years. (9)

Out of 130 study participants 92(70.8%) were Males while 38(29.2%) were Female which is similar to previous study done by Kumari M et al the incidence of VAP was more common in males 117 (87%) than in females 17 (13%). (10)

Out of 130 patients of Ventilator associated pneumonia 52(40%) patients expired while 78 (60%) patients survived. Out of all expired patients most common isolated organism was Pseudomonas 18(13.8%) followed by Escherichia coli 14(10.7%) and Klebsiella 9(6.9%) which is similar to previous study done by Panwar R et al, most common offending organism isolated in cases with early onset VAP is Pseudomonas aeruginosa (60%) followed by Klebsiella and Escherichia coli. (11)

Among 130 ventilator associated pneumonia patient’s maximum mortality occur in age group of 46 to 75 years which is similar to previous study done by Ranjan N et al noted that the mortality associated with VAP was highest in the age group of >55 years (64.29%), followed by 46-55 years (54.54%), 36-45 years (50%), 15-25 years (36.36%) and 26-35 years (30%) respectively. (12)

Ventilator associated pneumonia is a serious problem in ICU leading to longer hospital stay, higher treatment cost, mortality and morbidity. Pseudomonas is the most common organism in our institution. Prolonged mechanical ventilation is an important risk factor. Knowledge of locally prevalent organism and their susceptibility pattern can serve as a guide for clinician to initiate optimal empirical antibiotic therapy of VAP and also help to reduce the emergence of MDR strain. Effective sepsis practice like hand washing is widely considered as an important but underutilized measure to prevent nosocomial infections like VAP. Regular fumigation of ICU staff training and sterilization of ventilator will decrease the incidence of VAP cases.

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