Ventilator associated pneumonia: risk factors and preventive measures

Ventilator-Associated Pneumonia in Patients With Increased Intra-abdominal Pressure

Increased intra-abdominal pressure (IAP) is a significant clinical concern, which has been proven to cause significant adverse events in patients. Respiratory infections are a high-yield problem in the intensive care unit (ICU). In this study, we reviewed available literature regarding the relationship between elevated IAP and the development of ventilator-associated pneumonia (VAP) in mechanically ventilated patients. Patients with prolonged mechanical ventilation are prone to develop VAP. Longer hospitalization, prior use of antibiotics, and comorbidities make these patients more susceptible to infections. Multidrug-resistant VAP poses a vast threat to critically ill patients, as it is characterized by a shift in the microbiological profile of the disease, as well as difficulties in its treatment options. Elevated IAP could adversely affect mechanically ventilated patients, as it is associated with an elevated risk of microaspirations and altered patency of the intestinal barrier, thus comprising an important factor for developing VAP. In addition, elevated IAP can deteriorate pulmonary function and hemodynamic condition of the patient, adding an extra risk for developing VAP. In such frail conditions, these patients have compromised immune function and are at risk of developing systematic infection, even resulting in the failure of multiple organs. As the microbiologic profile shifts toward multidrug-resistant bacteria, there is a need for comprehensive strategies in ICU settings to mitigate the risks associated with both elevated IAP and multidrug-resistant VAP. Timely intervention and proper management can prevent the risk of difficult-to-treat infections and life-threatening adverse events for patients.

Risk Factors of Hospital-Acquired Pneumonia Among Hospitalized Patients With Cardiac Diseases

Background To our knowledge, no studies have been done in Saudi Arabia to determine the risk factors of hospital-acquired pneumonia (HAP) among hospitalized cardiac patients. This study aimed to assess these risk factors. Methods A retrospective study was done at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. Five hundred hospitalized patients diagnosed with pre-existing cardiovascular disease (CVD) were included. A checklist was used to collect data about patients' demographic characteristics; BMI; smoking and alcohol abuse; type of cardiac disease; other chronic diseases; exposure to immunosuppressives; chemotherapy and radiotherapy in the last six months; glucocorticoid use; application of ventilator; initial, follow-up chest X-ray results; pneumonia vaccination status; nasogastric tube use; general anesthesia received; use of loop diuretics; presence of pulmonary diseases; levels of WBC, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP); results of blood and respiratory cultures; number of hospitalizations and intensive care unit (ICU) admissions in the last six months; and Richmond Agitation and Sedation Scale (RASS) score. Results The prevalence of pneumonia was 7%. Females; patients with autoimmune diseases who were exposed to immunosuppressives or glucocorticoids; those with an initial or second abnormal chest X-ray; patients who used nasogastric tube, had pulmonary disease, and had high levels of WBC, ESR, or CRP; and patients hospitalized for more than two times had a significantly higher percentage of having pneumonia. Abnormal second chest X-ray, high ESR, and more than two times of hospitalization within the last six months were the risk factors of pneumonia on multivariate logistic regression analysis. Conclusion Better prevention and intervention programs are needed to assess the risk factors of pneumonia among admitted cardiac patients.

Incidence and Related Factors for Hospital-Acquired Pneumonia Among Older Bedridden Patients in China: A Hospital-Based Multicenter Registry Data Based Study

Objective: To identify the incidence and related factors for hospital-acquired pneumonia (HAP) among older bedridden patients in China. Study design and setting: This multicenter registry data-based study conducted between November 2015 and March 2016 surveyed 7,324 older bedridden patients from 25 hospitals in China (six tertiary, 12 non-tertiary, and seven community hospitals). The occurrence of HAP among all participants was monitored by trained investigators. Demographics, hospitalization information and comorbidity differences were compared between patients with and without HAP. A multilevel regression analysis was used to explore the factors associated with HAP. Results: Among 7,324 older bedridden patients, 566 patients were diagnosed with HAP. The incidence of HAP in this study was 13.9 per 1,000 person-days. There were statistical differences in gender, age, length of bedridden days, BMI, smoking, department, undergoing general anesthesia surgery, ventilator application, Charlson comorbity index (CCI) score, disturbance of consciousness, tranquilizer use, glucocorticosteroid use, and antibiotic use between patients with HAP and patients without HAP (all p < 0.05). Multilevel regression analysis found no significant variance for HAP at the hospital level (0.332, t = 1.875, p > 0.05). There were significant differences for the occurrence of HAP among different departments (0.553, t = 4.320, p < 0.01). The incidence density of HAP was highest in the ICU (30.1‰) among the selected departments, followed by the departments of neurosurgery (18.7‰) and neurology medicine (16.6‰). Individual patient-level factors, including older age, disturbance of consciousness, total CCI score, ICU admission, and glucocorticoid and antibiotic use, were found to be associated with the occurrence of HAP (all p < 0.05). Conclusion: A relatively high incidence density of HAP among older bedridden patients was identified, as well as several factors associated with HAP among the population. This suggests that attention should be paid to the effective management of these related factors of older bedridden patients to reduce the occurrence of HAP.

The impact of tracheostomy timing in patients with severe head injury: an observational cohort study

STUDY DESIGN

A retrospective analysis of 66 adults with severe head injury admitted to the neurosurgical intensive care unit (ICU) who required tracheostomy.

OBJECTIVE

The purpose of this cohort study was to examine the impact of the tracheostomy timing in patients with severe head injury.

METHODS

Patients were included in this study if they were admitted to the neurosurgical ICU because of severe head injury and if tracheostomy was performed. The patients were classified into 2 groups: early tracheostomy (ET) and late tracheostomy (LT). The timing of tracheostomy was considered early if it was performed by day 10 of mechanical ventilation and late if it was performed after day 10. We compared the duration of mechanical ventilation, length of stay (LOS) at ICU, hospital LOS, incidence of pneumonia, duration of antibiotics use, and mortality between the ET and LT groups.

RESULTS

Of the 2481 patients with severe head injury admitted to the neurosurgical ICU, 66 (2.7%) required tracheostomy; 16 of whom were in the ET group and 50 were in the LT group. The ICU LOS was significantly shorter in the ET group (p<0.001). The incidence of nosocomial pneumonia was lower in the ET group (p=0.04) and the duration of antibiotic use was significantly shorter in the ET group (p<0.001). The patients in the ET group had a lower incidence of pneumonia caused by gram-negative microorganisms (p=0.001).

CONCLUSIONS

ET in patients with severe head injury might contribute to a shorter duration of ICU LOS, lower incidence of gram-negative microorganism-related nosocomial pneumonia, and shorter duration of antibiotic use.

One evidence based protocol doesn't fit all: brushing away ventilator associated pneumonia in trauma patients

OBJECTIVES

Evaluate change in ventilator associated pneumonia (VAP) and nurse's attitudes, beliefs post implementation of an evidence based practice (EBP) oral hygiene protocol. METHODOLOGY/DESIGN/SETTING: Descriptive pre and post test design in two critical care units in a Level One Trauma Community Hospital. Oral hygiene protocol data was reanalysed to examine effects in medical surgical and trauma subgroups.

OUTCOME MEASURES

Oral care practices, attitudes and beliefs among nurses, and VAP rates according to Centers for Disease Control and Prevention guidelines.

RESULTS

Trauma rates increased from 6.4% to 10.0% (p=0.346), and medical/surgical rates decreased from 3.3% to 1.0% (p=0.042). Results revealed changes in nurses' beliefs regarding pre-admission colonisation (p=0.027) and having adequate training. Nurses' perception of facility support improved, by having suitable equipment and readily available supplies. Foam swabs with moisture agents at 4hours or less was 88.6% and toothbrush use at 12hours or less was 71%, with significant changes in frequency of oral care post intervention.

CONCLUSIONS

Trauma patients present with unique characteristics which compromise oral care. Understanding risk and prognostic factors, mechanisms of transmission and systemic inflammatory response are important when implementing EBP protocols. Nurses' attitudes, beliefs are important, and staff adherence considered when initiating EBP changes.

Emergency department predictors of tracheostomy in patients with isolated traumatic brain injury requiring emergency cranial decompression

Object

Patients with severe traumatic brain injury (TBI) frequently require a tracheostomy for prolonged mechanical ventilation and/or pulmonary toilet. It is now proven that the earlier the procedure is done, the more beneficial it is to the patient. The present study was carried out to determine if the requirement of a tracheostomy can be predicted on arrival of a patient to the emergency department. The prediction can potentially aid in combining the procedure with cranial decompression. In this study, the authors' aim was to determine the emergency department predictors of tracheostomy in patients with isolated TBI requiring emergency cranial decompression.

Methods

The authors performed a retrospective chart review of all patients who underwent surgery for isolated TBI and required more than 4 days of mechanical ventilation. Multivariate logistic regression analysis was used for predictive indicators.

Results

In patients with isolated severe TBI, a patient age of 31–50 years, the presence of preexisting medical comorbid conditions, a delay in emergency department arrival exceeding 1.5 hours, an abnormal pupil response on arrival, and a preoperative neurological worsening during hospital stay were independent predictors of the requirement for tracheostomy. These findings were validated in a small cohort of patients and were found to be significant.

Conclusions

Requirement of a tracheostomy can be predicted in patients with severe TBI on arrival to the emergency department. These results were validated in a small cohort of patients, and it was found that the positive predictive value of requirement of tracheostomy was directly proportional to the number of predictors present. Larger prospective studies with appropriate control groups are further recommended to validate the authors' findings.

Is There a Benefit to Multidisciplinary Rounds in an Open Trauma Intensive Care Unit regarding Ventilator-Associated Pneumonia?

Multidisciplinary rounds (MDRs) have been instituted for patient care since June 2005. Before June 2005, all care was provided by individual practitioners. MDRs include the surgical intensivist, surgical resident, patient's nurse, case manager, pharmacist, chaplain, nutritionist, and respiratory therapist. Our study examined the effect of MDRs on ventilator-associated pneumonia in trauma patients in open intensive care units (ICUs). Group 1 included patients from June 2003 to May 2005 before the implementation of MDRs, and Group 2 included patients after the institution of MDRs from June 2005 to May 2007. In Group 1, there were 83 ventilator-associated pneumonias (VAPs) during 2414 ventilator days. In Group 2, there were 49 VAPs during 2094 ventilator days. The ratio of VAPs per thousand ventilator days decreased from 34.4 to 23.4 between the two groups ( P = 0.04). When comparing trauma patients in our open ICU with similar mean Injury Severity Score and mean Abbreviated Injury Score for chest and for head and neck, implementing MDRs significantly decreased our incidence of VAP.

Acute phase response impairs host defense against Pseudomonas aeruginosa pneumonia in mice

OBJECTIVE

Pseudomonas aeruginosa is a common pathogen in hospital-acquired pneumonia. Especially trauma and postsurgical patients display a profound acute phase protein response and are susceptible to acquiring pneumonia. The objective was to study the influence of the acute phase response induced by sterile tissue injury on pulmonary host defense.

DESIGN

Laboratory investigation.

SETTING

Academic medical center.

SUBJECTS

Female C57Bl/6 wild-type mice, 8-10 wks old.

INTERVENTIONS

Mice were injected subcutaneously with either turpentine or sterile saline (control) in both hind limbs 1 day before intranasal infection with P. aeruginosa.

MEASUREMENTS AND MAIN RESULTS

The turpentine-induced acute phase response was associated with 100% lethality after induction of pneumonia, whereas control mice all survived the Pseudomonas infection. In addition, turpentine-injected mice demonstrated much higher bacterial loads in their lungs and an increased dissemination of the infection. The acute phase reaction attenuated lung inflammation during pneumonia, as reflected by histopathology, reduced pulmonary levels of proinflammatory cytokines, and a strongly diminished recruitment of neutrophils to the site of infection. Blood neutrophils harvested from turpentine injected mice displayed a reduced capacity to up-regulate their CD11b/CD18 expression upon stimulation with Pseudomonas ex vivo and during Pseudomonas pneumonia in vivo. Administration of a blocking anti-CD11b antibody to turpentine-injected and control mice almost completely abrogated the difference in bacterial outgrowth, whereas inhibition of the sympathetic nervous system did not affect the impaired pulmonary host defense in mice with an acute phase response.

CONCLUSIONS

These data suggest that a systemic acute phase response might impair host defense against P. aeruginosa pneumonia, possibly in part by inhibition of CD11b/CD18-dependent neutrophil recruitment.

Early tracheostomy in closed head injuries: experience at a tertiary center in a developing country--a prospective study

BACKGROUND

An important factor contributing to the high mortality in patients with severe head trauma is cerebral hypoxia. The mechanical ventilation helps both by reduction in the intracranial pressure and hypoxia. Ventilatory support is also required in these patients because of patient's inability to protect the airway, persistence of excessive secretions, and inadequacy of spontaneous ventilation. Prolonged endotracheal intubation is however associated with trauma to the larynx, trachea, and patient discomfort in addition to requirement of sedatives. Tracheostomy has been found to play an integral role in the airway management of such patients, but its timing remains subject to considerable practice variation. In a developing country like India where the intensive care facilities are scarce and rarely available, these critical patients have to be managed in high dependency cubicles in the ward, often with inadequately trained nursing staff and equipment to monitor them. An early tracheostomy in the selected group of patients based on Glasgow Coma Score(GCS) may prove to be life saving. Against this background a prospective study was contemplated to assess the role of early tracheostomy in patients with isolated closed head injury.

METHODS

The series consisted of a cohort of 50 patients admitted to the surgical emergency with isolated closed head injury, that were not considered for surgery by the neuro-surgeon or shifted to ICU, but had GCS score of less than 8 and SAPS II score of more than 50. First 50 case records from January 2001 that fulfilled the criteria constituted the control group. The patients were managed as per ATLS protocol and intubated if required at any time before decision to perform tracheostomy was taken. These patients were serially assessed for GCS (worst score of the day as calculated by senior surgical resident) and SAPS scores till day 15 to chart any changes in their status of head injuries and predictive mortality. Those patients who continued to have a GCS score of <8 and SAPS score of >50 for more than 24 hours (to rule out concussion or recovery) underwent tracheostomy. All these patients were finally assessed for mortality rate and hospital stay, the statistical analysis was carried out using SPSS10 version. The final outcome (in terms of mortality) was analyzed utilizing chi-square test and p value <0.05 was considered significant.

RESULTS

At admission both tracheostomy and non-tracheostomy groups were matched with respect to GCS score and SAPS score. The average day of tracheostomy was 2.18 +/- 1.0038 days. The GCS scores on days 1, 2, 3, 4, 5, 10 between tracheostomy and non-tracheostomized group were comparable. However the difference in the GCS scores was statistically significant on day 15 being higher in the tracheostomy group. Thus early tracheostomy was observed to improve the mortality rate significantly in patients with isolated closed head injury.

CONCLUSION

It may be concluded that early tracheostomy is beneficial in patients with isolated closed head injury which is severe enough to affect systemic physiological parameters, in terms of decreased mortality and intubation associated complications in centers where ICU care is not readily available. Also, in a selected group of patients, early tracheostomy may do away with the need for prolonged mechanical ventilation.

Efficacy of heat and moisture exchangers in preventing ventilator-associated pneumonia: meta-analysis of randomized controlled trials

OBJECTIVE

Several randomized controlled trials (RCT) have examined the effect of antibacterial humidification strategies, particularly the replacement of heated humidifiers (HH) by heat and moisture exchangers (HME), in preventing ventilator-associated pneumonia (VAP). The present meta-analysis reviews these RCTs.

METHODS

RCTs were identified by searching the Medline and Cochrane Central Register of Controlled Trials databases from 1990 to 2003. We included RCTs using HMEs in the treatment group and HHs in the control group and reporting the incidence of pneumonia as a study outcome. Two investigators independently abstracted key data on design, population, intervention and outcome of the studies.

RESULTS

Between 1990 and 2003 eight RCTs met the inclusion criteria of this analysis. Pooling the results from these studies revealed a reduction in the relative risk of VAP in the HME group (0.7), particularly in MV with a duration of at least 7 days (five RCTs, relative risk 0.57).

CONCLUSIONS

This meta-analysis found a significant reduction in the incidence of VAP in patients humidified with HMEs during MV, particularly in patients ventilated for 7 days or longer. This finding is limited by the exclusion of patients at high risk for airway occlusion from some of the studies. Moreover, contraindications (tenacious secretions, airway obstructive disease, hypothermia) and technical issues of HMEs must be considered. Further RCTs are necessary to examine the wider applicability of HMEs and their extended use.

Do proton pump inhibitors increase the incidence of nosocomial pneumonia and related infectious complications when compared with histamine-2 receptor antagonists in critically ill trauma patients?

BACKGROUND

Proton pump inhibitors (PPI) may increase the risk of nosocomial pneumonia caused by profound irreversible gastric acid suppression. The study purpose was to characterize differences in nosocomial pneumonia and related infections in trauma patients administered either histamine2-receptor antagonists (H2RA) or PPI.

METHODS

Observational evaluation of consecutive critically ill adult trauma patients administered either omeprazole or famotidine during a 22-month period. Nosocomial infection was evaluated daily based on published CDC definitions.

RESULTS

Eighty of 269 patients fulfilled study criteria. The PPI group (n = 40) exhibited increased baseline risk for infection, demonstrated by higher ISS (p = 0.020), more chest tube placements (p = 0.031), and increased chest trauma (p = 0.025). Overall number of patients infected per group included 33% and 40% of patients administered PPI and H2RA, respectively (p = 0.64). Despite baseline differences, the incidence of nosocomial infection was similar (p = 0.87), and extrapolation of pneumonia based on 1000 patient days revealed a ratio 51.7 vs 52.2 in the PPI vs H2RA groups, respectively, which was not significant (p = 0.99).

CONCLUSIONS

Proton pump inhibitor administration does not increase risk of nosocomial pneumonia or other nosocomial infections compared with H2RA therapy in the critically ill trauma patient.

Early tracheostomy in intensive care trauma patients improves resource utilization: a cohort study and literature review

INTRODUCTION

Despite the integral role played by tracheostomy in the management of trauma patients admitted to intensive care units (ICUs), its timing remains subject to considerable practice variation. The purpose of this study is to examine the impact of early tracheostomy on the duration of mechanical ventilation, ICU length of stay, and outcomes in trauma ICU patients.

METHODS

The following data were obtained from a prospective ICU database containing information on all trauma patients who received tracheostomy over a 5-year period: demographics, Acute Physiology and Chronic Health Evaluation II score, Simplified Acute Physiology Score II, Glasgow Coma Scale score, Injury Severity Score, type of injuries, ICU and hospital outcomes, ICU and hospital length of stay (LOS), and the type of tracheostomy procedure (percutaneous versus surgical). Tracheostomy was considered early if it was performed by day 7 of mechanical ventilation. We compared the duration of mechanical ventilation, ICU LOS and outcome between early and late tracheostomy patients. Multivariate analysis was performed to assess the impact of tracheostomy timing on ICU stay.

RESULTS

Of 653 trauma ICU patients, 136 (21%) required tracheostomies, 29 of whom were early and 107 were late. Age, sex, Acute Physiology and Chronic Health Evaluation II score, Simplified Acute Physiology Score II and Injury Severity Score were not different between the two groups. Patients with early tracheostomy were more likely to have maxillofacial injuries and to have lower Glasgow Coma Scale score. Duration of mechanical ventilation was significantly shorter with early tracheostomy (mean +/- standard error: 9.6 +/- 1.2 days versus 18.7 +/- 1.3 days; P < 0.0001). Similarly, ICU LOS was significantly shorter (10.9 +/- 1.2 days versus 21.0 +/- 1.3 days; P < 0.0001). Following tracheostomy, patients were discharged from the ICU after comparable periods in both groups (4.9 +/- 1.2 days versus 4.9 +/- 1.1 days; not significant). ICU and hospital mortality rates were similar. Using multivariate analysis, late tracheostomy was an independent predictor of prolonged ICU stay (>14 days).

CONCLUSION

Early tracheostomy in trauma ICU patients is associated with shorter duration of mechanical ventilation and ICU LOS, without affecting ICU or hospital outcome. Adopting a standardized strategy of early tracheostomy in appropriately selected patients may help in reducing unnecessary resource utilization.

Stress-related mucosal disease: risk factors and prophylactic therapy

BACKGROUND

The term stress-related mucosal disease (SRMD) represents a continuum of conditions ranging from stress-related injury (superficial mucosal damage) to stress ulcers (focal deep mucosal damage). Caused by mucosal ischemia, SRMD is most commonly seen in critically ill patients in the intensive care unit (ICU). Prophylaxis of stress ulcers may reduce major bleeding but has not yet been shown to improve survival.

OBJECTIVES

This article reviews currently available agents for the prophylaxis of SRMD and discusses their uses and potential adverse effects.

METHODS

Relevant articles in the English-language literature were identified through a MEDLINE search (1968-2003) using the key words stress-related mucosal disease, stress-related injury, ulcer, prophylaxis, intensive care unit, and upper gastrointestinal bleeding.

RESULTS

The most widely used drugs for stress-related injury are the intravenous histamine(2)-receptor antagonists. These drugs raise gastric pH but are associated with the development of tolerance and possible drug interactions and neurologic manifestations. Sucralfate, which can be administered by the nasogastric route, can protect the gastric mucosa without raising pH, but may decrease the absorption of concomitantly administered oral medications. The prostaglandin misoprostol has not been shown to be of benefit in the prophylaxis of SRMD. Antacids lower the risk of gastrointestinal bleeding, but large volumes of antacids are required and treatment is labor intensive. Proton pump inhibitors (PPIs) are the most potent acid-suppressive pharmacologic agents available. Esomeprazole, lansoprazole, omeprazole, pantoprazole, and rabeprazole substantially raise gastric pH for up to 24 hours after a single dose. The availability of an intravenous formulation of pantoprazole may help improve the treatment of SRMD in ICU patients, particularly those receiving mechanical ventilation. Tolerance does not develop, and few adverse effects have been reported.

CONCLUSIONS

Recent studies of PPIs have shown promising results in high-risk patients, making this class of drugs an option for the prophylaxis of SRMD.

Costs and risk factors for ventilator-associated pneumonia in a Turkish university hospital's intensive care unit: a case-control study

Background

Ventilator-associated pneumonia (VAP) which is an important part of all nosocomial infections in intensive care unit (ICU) is a serious illness with substantial morbidity and mortality, and increases costs of hospital care. We aimed to evaluate costs and risk factors for VAP in adult ICU.

Methods

This is a-three year retrospective case-control study. The data were collected between 01 January 2000 and 31 December 2002. During the study period, 132 patients were diagnosed as nosocomial pneumonia of 731 adult medical-surgical ICU patients. Of these only 37 VAP patients were assessed, and multiple nosocomially infected patients were excluded from the study. Sixty non-infected ICU patients were chosen as control patients.

Results

Median length of stay in ICU in patients with VAP and without were 8.0 (IQR: 6.5) and 2.5 (IQR: 2.0) days respectively (P < 0.0001). Respiratory failure (OR, 11.8; 95%, CI, 2.2–62.5; P < 0.004), coma in admission (Glasgow coma scale < 9) (OR, 17.2; 95% CI, 2.7–107.7; P < 0.002), depressed consciousness (OR, 8.8; 95% CI, 2.9–62.5; P < 0.02), enteral feeding (OR, 5.3; 95% CI, 1.0–27.3; P = 0.044) and length of stay (OR, 1.3; 95% CI, 1.0–1.7; P < 0.04) were found as important risk factors. Most commonly isolated microorganism was methicillin resistant Staphylococcus aureus (30.4%). Mortality rates were higher in patients with VAP (70.3%) than the control patients (35.5%) (P < 0.003). Mean cost of patients with and without VAP were 2832.2+/-1329.0 and 868.5+/-428.0 US Dollars respectively (P < 0.0001).

Conclusion

Respiratory failure, coma, depressed consciousness, enteral feeding and length of stay are independent risk factors for developing VAP. The cost of VAP is approximately five-fold higher than non-infected patients.