Risk factors for ventilator-associated pneumonia in patients with chest trauma in intensive care unit

Risk factors for ventilator-associated pneumonia in patients with severe traumatic brain injury in a Serbian trauma centre

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.

Objective To analyze the high risk factors and prognosis of patients with ventilator associated pneumonia(VAP) treated with mechanical ventilation(MV) in Intensive Care Unit(ICU), and to provide theoretical evidence for effective treatment and prevention. Methods From January 2015 to January 2017, 156 MV patients treated in ICU of Shaoxing Municipal Hospital were enrolled retrospectively.According to the occurrence of VAP, the patients were divided into VAP group(76 cases) and non-VAP group(80 cases). The data including sex, age, ICU time, MV time, cases of withdrawing machine failure, prognosis, serum albumin, blood glucose levels, APACHE Ⅱ score, types of antibiotics and days of continuous applying were recorded.Single factor χ2 test and multiple factor logistic regression analysis were used to analyze the high-risk factors and prognosis related to occurrence of VAP. Results Univariate analysis showed that the age, mortality, serum albumin and blood glucose levels, MV time, weaning failure rate, APACHE Ⅱ score, antibiotic combination type and days of continuous use, application of H2 receptor antagonists time between, the VAP group and non-VAP group had statistically significant differences (χ2=6.568, 16.558, 5.132, 5.896, 27.043, 15.018, 48.863, 46.752, 27.431, 3.981, P=0.010, 0.000, 0.023, 0.015, 0.000, 0.000, 0.000, 0.000, 0.000, 0.046). After age adjustment, logistic regression analysis showed that serum albumin 5 days, APACHE Ⅱ score>15 points, antibiotics continuous use>3 days, and antibiotic combination type>2 were independent risk factors for VAP(χ2=5.115, 5.984, 21.252, 18.043, 9.008, 14.545, P=0.030, 0.026, 0.000, 0.000, 0.007, 0.001). Compared with surviving patients with VAP, death patients lived longer in ICU and MV, and APACHE Ⅱ scores were higher(t=4.136, 6.382, 7.312, P=0.000, 0.000, 0.000). Conclusion There are multiple high-risk factors of VAP in patients treated with MV in ICU.The death demonstrated longer ICU time, MV time and higher APACHE Ⅱ score, need to be strengthened monitoring, early prevention and treatment. Key words: Pneumonia, ventilator-associated; Respiration, artificial; Risk factor; Prognosis; Intensive care units; Universal precautions; Glucocorticoids; Anti-bacterial agents; Albumin

Ventilator-associated pneumonia (VAP) is one of the most frequent hospital-acquired infections, which develops in mechanically ventilated patients after 48 hours of mechanical ventilation. The purpose of this study was to determine the incidence rate, various risk factors, microbiological profile, and outcome of early- vs late-onset ventilator-associated pneumonia (VAP) in medical intensive care unit (MICU). This prospective study was conducted on 273 patients admitted to the MICU in JIPMER, Puducherry, from October 2018 to September 2019. The incidence of VAP was 39.59 per 1000 ventilation days of MICU patients (93/273). Of these, 53 (56.9%) patients had early-onset VAP and 40 (43.1%) had late-onset VAP. Multiple logistic regression analysis showed that steroid therapy, supine head position, coma or impaired unconsciousness, tracheostomy, and re-intubation were found to be independent predictors of early- and late-onset VAP, respectively. Most cases of VAP were caused by Gram-negative bacteria (90.6%), with nonfermenters contributing to 61.8%. The most frequent pathogens causing early-onset VAP were Acinetobacter baumannii (28.9%) and Pseudomonas aeruginosa (20.6%), while in late-onset VAP, A. baumannii (32.9%) and Klebsiella pneumoniae (21.9%) were the most common. Maximum death rate was seen in patients infected with Escherichia coli (50%) and Stenotrophomonas maltophilia (38.5%). There was no significant association between the presence of VAP and mortality among the studied population. The incidence of VAP in our study was high. There were no significant differences in the prevalence of pathogens associated with early-onset or late-onset VAP. Our study shows that early-onset and late-onset VAP have different risk factors, highlighting the need for developing different preventive and therapeutic strategies. Gunalan A, Sastry AS, Ramanathan V, Sistla S. Early- vs Late-onset Ventilator-associated Pneumonia in Critically Ill Adults: Comparison of Risk Factors, Outcome, and Microbial Profile. Indian J Crit Care Med 2023;27(6):411-415.

COMPARISON OF THE BACTERIAL ETIOLOGY OF EARLY-ONSET VENTILATOR-ASSOCIATED PNEUMONIA AND LATE-ONSET VENTILATOR-ASSOCIATED PNEUMONIA IN PATIENTS ENROLLED IN 2 LARGE CLINICAL STUDIES

Ventilator-associated pneumonia (VAP) is a leading cause of morbidity in the perioperative period. Based on differences in causes, VAP has been divided into early (</=96 hours of admission) and late (>96 hours of admission) onset. We sought to compare differences in patient characteristics and outcome between early- and late-onset VAP in trauma and nontrauma surgical patients. A retrospective analysis of prospectively collected data were performed for all surgical and trauma patients admitted to the surgical or trauma intensive care unit of an academic medical center from December 1996 to March 2005 who developed VAP. Patients with early- and late-onset VAP were compared with regard to patient characteristics, cause, and outcome using bivariate and multivariate analyses. Three hundred thirty VAPs were identified in 233 trauma (71%) and 97 nontrauma surgery patients (29%). There was no statistically significant difference in recurrence, mortality, or length of stay between early- and late-onset VAP in trauma patients. Mortality for late- onset VAPs in nontrauma patients was 44% versus 23% for early-onset VAPs (p = 0.09). On a per case basis, trauma patients had significantly better mortality (11% vs. 41%) and length of stay (33.1 +/- 1.4 vs. 55.8 +/- 4.1 days) than nontrauma surgical patients with VAP (p < 0.0001), although the rate of VAP-related death favored the nontrauma patients (1.8 deaths of 100 intensive care unit trauma admissions vs. 1.1 deaths of 100 intensive care unit nontrauma admissions, p = 0.05). Although there is a trend toward worse outcome in nontrauma patients with late-onset VAP, trauma patients with late- and early-onset VAP behave similarly. On a per case basis, trauma patients have significantly better outcomes than nontrauma surgical patients with VAP when cared for within the same surgical or trauma intensive care unit.

Ventilator-associated pneumonia (VAP) is the most frequent intensive care unit (ICU)-acquired infection. The etiology of VAP and their antimicrobial susceptibility pattern varies with different patient populations and types of ICUs. An observational cross-sectional study was performed over a period of 2 years in a tertiary care hospital to determine the various etiological agents causing VAP and to detect the presence of multidrug-resistant (MDR) pathogens in these VAP patients. Combination disk method, Modified Hodge test, ethylenediaminetetraacetic acid disk synergy test, and AmpC disk test were performed for the detection of extended-spectrum beta-lactamase (ESBL), carbapenemases, metallo-beta-lactamases (MBL), and AmpC beta-lactamases, respectively. The prevalence of VAP was 35%. Enterobacteriaceae (66.66%) and Staphylococcus aureus (20%) were common in early-onset VAP, while nonfermenters (50%) and Enterobacteriaceae (40.61%) were predominant from late-onset VAP. Nearly 60.87% of the bacterial pathogens were MDR. ESBL was produced by 21.74% of Enterobacteriaceae. AmpC β-lactamase was positive in 35.29% nonfermenters and 26.08% Enterobacteriaceae. MBL was positive in 17.64% nonfermenters and 17.39% Enterobacteriaceae. Among the S. aureus isolates, 75% were cefoxitin resistant. Prior antibiotic therapy (P = 0.001) and hospitalization of 5 days or more (P = 0.001) were independent risk factors for VAP by MDR pathogens. polymyxin B, tigecycline, and vancomycin were the most sensitive drugs for Gram-negative and positive isolates respectively from VAP. SPSS for Windows Version SPSS 17.0 (SPSS Inc., Chicago, IL, USA) and Chi-square with Yates correction. Late-onset VAP is increasingly associated with MDR pathogens. Treatment with polymyxin B, tigecycline, and vancomycin should be kept as last-line reserve drugs against most of the MDR pathogens.

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in trauma patients, with a high mortality rate. Blood transfusion has been identified as an independent risk factor for VAP in critically ill patients. Prior studies in trauma are limited by retrospective design, lack of multivariable analyses, and scant data on the timing of transfusion. We examined critically the relation between blood product transfusion and VAP in trauma patients. Prospective observational cohort study of 766 trauma patients admitted to the intensive care unit (ICU), who received mechanical ventilation (MV) for >or= 48 h, and who did not have pneumonia on admission. Late-onset VAP was defined as that occurring >or= 72 h after MV. Only transfusions of red blood cell (RBC) concentrate, fresh-frozen plasma (FFP), or platelets before the onset of VAP were considered. Logistic regression analyses controlled for all variables related significantly to VAP by univariate analysis (sex, Injury Severity Score, and ventilator days and ICU length of stay prior to VAP). A significantly greater proportion of male patients developed VAP. Patients with VAP had a longer duration of MV: The mean number ventilator days prior to VAP was 11.1 +/- 8.0. Transfusion of blood products was an independent risk factor for VAP, and the risk increased with more units transfused. All blood products were associated with a higher risk of VAP (RBC: odds ratio [OR] 4.41; 95% confidence interval [CI] 1.00, 19.54; p = 0.05; FFP: OR 3.34; 95% CI 1.18, 9.43; p = 0.023; platelets: OR 4.19; 95% CI 1.37, 12.83; p = 0.012). Blood product transfusion is an independent risk factor for VAP in trauma, and the odds ratio is significantly higher (3.34-4.41) than in published studies of other types of ICU patients (1.89). To reduce the incidence of VAP, all efforts to reduce the transfusion of blood products to trauma patients should be implemented.

Background:Ventilator-Associated Pneumonia (VAP) is the main cause of nosocomial infection at intensive care units (ICUs), which causes high mortality and morbidity.Objectives:The objective of the present survey was to identify the VAP risk and prognostic factors among poisoned patients, who were admitted to the toxicological ICU (TICU), especially central nervous system (CNS) depressants due to their prevalence and importance.Patients and Methods:A case-control study was conducted at the Loghman Hakim hospital between March 2013 and March 2014. Among 300 poisoned patients with mechanical ventilator ≥ 48 hours, 150 patients, who had developed microbiologically-confirmed VAP were considered as the VAP group and 150 without VAP were defined as the control group. The following data were collected; age, gender, type of poisoning, glasgow coma score, Acute physiology and chronic health evaluation (APACHE) II score, length of hospital stay, previous antibiotic use, microbial culture of the trachea, body temperature, leukocyte count, and patients’ outcome. Based on the type of poisoning, patients were divided into three groups including: opioid, CNS depressants and others. All data were expressed as means (SD) for continuous variables and frequencies for categorical variables. Logistic regression was used to determine the relationship between risk factors and VAP.Results:The mean age of the patients was 33.9 ± 14.3 years. The probable VAP incidence and mortality were 22% and 18.6%, respectively. The rate of CNS depressant versus opioid use (odds ratio, 3.74; P < 0.027), APACHE II (odds ratio, 1.28; P < 0.000) and length of hospital stay (odds ratio, 2.15; P < 0.000) were the independent risk factors for VAP. While, the APACHE II score (odds ratio, 1.12; P < 0.044) and length of hospital stay (odds ratio, 2.15; P < 0.000) were the independent predictors of VAP mortality among these patients. The most common microorganisms in VAP cases were Methicillin-Resistant Staphylococcus aureus (MRSA) and Acinetobacter sp. (56.7% and 12.7%, respectively).Conclusions:Central nervous system depressant was an important risk factor for VAP among poisoned patients. Hypoventilation due to CNS depression can lead to VAP. The APACHE II and length of hospital stay were shown as independent predictors of VAP and mortality among these patients.

Ventilator-Associated Pneumonia

Introduction: Ventilator-associated pneumonia (VAP) occurs in an estimated 40–60% of patients with traumatic brain injury (TBI). Risk factors include male sex, TBI severity, thoracic trauma, elevated head-acute injury scores, and blood transfusion. However, diagnostic criteria are inconsistent, with many studies requiring microbiologic confirmation despite guidelines favoring a clinical diagnosis. We aimed to evaluate the incidence, risk factors, and outcomes of VAP in mechanically ventilated TBI patients. Methods: This multicenter, retrospective review included adult TBI patients mechanically ventilated in surgical ICUs across 3 NYU academic medical centers over a 3-year period. Patients chronically intubated or who died within 48 hours were excluded. VAP was defined as a new pulmonary infiltrate on imaging plus at least 2 of the following: fever of 38°C or higher, purulent sputum, leukocytosis, or hypoxia. Demographics, comorbidities, injury severity, and outcomes were extracted from the electronic medical record. Multivariate analysis was used to identify independent risk factors for VAP or mortality. Results: Among 100 patients included, VAP incidence was 64.0%. VAP patients had longer duration of mechanical ventilation (median 35.2 vs 6.6 days; p< 0.001), hospital stay (39.0 vs 17.1 days; p< 0.001), and higher rates of tracheostomy (82.8% vs 22.2%; p< 0.001) and percutaneous endoscopic gastrostomy (PEG) placement (76.6% vs 33.3%; p< 0.001). More VAP patients were discharged to long-term care (46.9% vs 11.1%; p< 0.001). Independent risk factors for VAP or death included age (OR 1.1; p=0.039), multiple intracranial injuries (OR 10.3; p=0.002), presence of midline shift (OR 6.4; p=0.019), PF ratio below 200 (OR 21.4; p=0.027), and injury mechanism other than fall (OR 5.8; p=0.047). Conclusions: VAP occurred in nearly 2/3 of ventilated TBI patients and was associated with longer hospitalization and increased procedures. Although crude mortality was lower in VAP patients, this likely reflects survivorship bias, as early deaths precluded VAP development. Risk factors for VAP or mortality included older age, multiple intracranial injuries, presence of midline shift, PF ratio, and injury mechanism other than fall. Future direction for the project includes a VAP prophylaxis protocol in high risk TBI patients.

Several interventions have been shown to be effective in reducing the incidence of ventilator-associated pneumonia (VAP), but their implementation in clinical practice has not gained widespread acceptance. To determine the impact of a protocol that incorporates evidence-based interventions shown to reduce the frequency of VAP on the overall rate of VAP, early-onset VAP, and late-onset VAP in the intensive care unit (ICU) of a tertiary care adult teaching hospital. This pre- and postintervention observational study included mechanically ventilated patients admitted to the Montreal General Hospital ICU between November 2003 and May 2004 (preintervention) and between November 2004 and May 2005 (postintervention). A multidisciplinary prevention protocol was developed, implemented, and reinforced. Rates of VAP per 1000 ventilator-days were calculated pre- and postprotocol implementation for all patients, for patients with early-onset VAP, and for those with late-onset VAP. In the pre- and postintervention groups, 349 and 360 patients, respectively, were mechanically ventilated. Twenty-three VAP episodes occurred in 925 ventilator-days (crude incidence rate 25 per 1000) in the preintervention period. Following implementation, the VAP rate decreased to 22 episodes in 988 ventilator-days (crude incidence rate 22.3 per 1000), corresponding to a relative reduction in rate of 10.8% (p < 0.001). The incidence of early-onset VAP decreased from 31.0 to 18.5 VAP per 1000 ventilator-days (p < 0.001), while the incidence of late-onset VAP increased from 21.9 to 24.1 VAP per 1000 ventilator-days (p < 0.001). However, when all covariates were adjusted, the impact of the prevention protocol was not statistically significant. Implementation of a VAP prevention protocol incorporating evidence-based interventions reduced the crude incidence of VAP, early-onset VAP, and late-onset VAP. However, when covariates were adjusted, the beneficial effect was no longer observed. Further research is needed to assess the impact of such measures on VAP, early-onset VAP, and late-onset VAP.

To determine the impact of aerosolized bronchodilators on ventilator-associated pneumonia. Prospective cohort study. A 30-bed medical and surgical intensive care unit. All intubated patients requiring mechanical ventilation for >48 hrs were eligible during a 13-month period. Nebulized β2-agonists were administered at the intensive care unit physician's discretion. Ventilator-associated pneumonia definition included clinical and quantitative microbiological criteria. Only first ventilator-associated pneumonia episodes were analyzed. Risk factors for ventilator-associated pneumonia were determined using univariate and multivariate analyses. The influence of inhaled β2-agonists on ventilator-associated pneumonia occurrence was also adjusted for confounding factors using Cox's proportional-hazards model. Ventilator-associated pneumonia was diagnosed in 137 (31%) of the 439 enrolled patients. Ventilator-associated pneumonia was early-onset in 14 (10%) patients. The incidence rate of ventilator-associated pneumonia was 20 per 1,000 ventilator days. Ventilator-associated pneumonia was polymicrobial in 16 (11%) patients, and related to multidrug-resistant bacteria in 42 (28%) patients. Most cases of ventilator-associated pneumonia were caused by Gram-negative bacteria. Inhaled β2-agonists were significantly more frequently used in patients with ventilator-associated pneumonia compared with those without ventilator-associated pneumonia (49% vs. 34%, odds ratio [95% confidence interval] = 1.9 [1.2-2.8], p = .003). Multivariate analysis identified aerosolized β2-agonists (odds ratio [95% confidence interval] = 1.7 [1.1-2.6], p = .012), Simplified Acute Physiology Score II at intensive care unit admission (odds ratio [95% confidence interval] = 1.01 [1.001-1.02] per point, p = .031), and red blood cell transfusion (odds ratio [95% confidence interval] = 2 [1.3-3.1], p = .001) as independent risk factors for ventilator-associated pneumonia. Cox's proportional-hazards model also identified inhaled β2-agonists as a risk factor for ventilator-associated pneumonia (odds ratio [95% confidence interval] = 1.52 [1.06-2.19], p = .021). Use of aerosolized bronchodilators in intensive care unit mechanically ventilated patients is an independent risk factor for ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is a common type of nosocomial pneumonia encountered in intensive care units. There are several aetiological agents which make treatment challenging. Improper antibiotic treatment of ventilated patients may lead to the emergence of multidrug resistant (MDR) pathogens. A prospective study was performed over a period of 20 months. Our study had two arms: the first, 'Incidence and risk factors of VAP in a tertiary care hospital' was the subject of an earlier publication; we therefore present the second investigative arm in this work. The aetiological agents of patients on mechanical ventilation (MV) were identified by standard bacteriological method. The susceptibility pattern was evaluated by Kirby-Bauer disc diffusion method. Extended spectrum beta lactamase (ESBL) testing was performed by combination disc method, and metallo-beta lactamase (MBL) testing was performed by EDTA disk synergy test (EDS). Late-onset VAP was associated with Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli, while early-onset VAP was commonly caused by members of Enterobacteriaceae, Candida albicans and Staphylococcus aureus. 72.2 per cent of VAP patients had monomicrobial and 27.8 per cent had polymicrobial infection. Out of the 24 isolates obtained from patients with VAP, seven (29.2 per cent) were MDR pathogens. ESBL and MBL production was detected in 40 per cent and 20 per cent of Klebsiella pneumoniae isolated in our study. Around 50 per cent of isolates associated with late-onset VAP were MDR, while 22.2 per cent isolates obtained from patients with earlyonset VAP were MDR. VAP is a nosocomial pneumonia that is common among ventilated patients. The aetiological agents vary from common organisms to MDR pathogens that are difficult to treat. A proper knowledge of MDR pathogens and early isolation followed by prevention of prolonged antibiotic therapy can reduce the mortality of late onset VAP.

Ventilator-associated pneumonia (VAP) in neonates has been associated with high mortality and poor outcome. This study aimed to compare the incidence, risk factors, and outcomes of VAP and non- VAP conditions in neonates. We performed a prospective cohort study in a neonatal intensive care unit (NICU) in Thailand from January 2014 to December 2014. All neonatal patients who were ventilated more than 48 hours were enrolled. There were 128 enrolled patients. The median (inter quartile range) gestational age and birthweight were 35 (30.2, 37.8) weeks and 2380 (1323.8, 3020.0) g. There were 17 VAP patients (19 episodes) and 111 non-VAP ones. The VAP rate was 13.3% or 10.1 per 1000 ventilator days. According to the multivariate analysis, a birthweight less than 750 g [adjusted odds ratio (aOR)=10.75, 95% confidence interval (CI)=2.35-49.16; P=0.002] and sedative medication use (aOR=4.00, 95% CI=1.23-12.50; P=0.021) were independent risk factors for VAP. Compared with the non-VAP group, the median difference in the VAP group yielded a significantly longer duration of NICU stay (18 days, P=0.001), total length of hospital stay (16 days, P=0.002) and higher hospital costs ($5113, P=0.001). The inhospital mortality rate in the VAP and non-VAP groups was 17.6% and 15.3% (P=0.73), respectively. A neonatal birthweight less than 750 g and sedative medication use were independent risk factors for VAP. Our VAP patients experienced a longer duration of both NICU and hospital stay, and incurred higher hospitalization costs.