Long-term medical utilization following ventilator-associated pneumonia in acute stroke and traumatic brain injury patients: a case-control study

Modelling lung infection with Klebsiella pneumoniae after murine traumatic brain injury

Pneumonia is a common comorbidity in patients with severe traumatic brain injury (TBI), and is associated with increased morbidity and mortality. In this study, we established a model of intratracheal Klebsiella pneumoniae administration in young adult male and female mice, at 4 days following an experimental TBI, to investigate how K. pneumoniae infection influences acute post-TBI outcomes. A dose-response curve determined the optimal dose of K. pneumoniae for inoculation (1 x 10^6 colony forming units), and administration at 4 days post-TBI resulted in transient body weight loss and sickness behaviors (hypoactivity and acute dyspnea). K. pneumoniae infection led to an increase in pro-inflammatory cytokines in serum and bronchoalveolar lavage fluid at 24 h post-infection, in both TBI and sham (uninjured) mice. By 7 days, when myeloperoxidase + neutrophil numbers had returned to baseline in all groups, lung histopathology was observed with an increase in airspace size in TBI + K. pneumoniae mice compared to TBI + vehicle mice. In the brain, increased neuroinflammatory gene expression was observed acutely in response to TBI, with an exacerbated increase in Ccl2 and Hmox1 in TBI + K. pneumoniae mice compared to either TBI or K. pneumoniae alone. However, the presence of neuroinflammatory immune cells in the injured brain, and the extent of damage to cortical and hippocampal brain tissue, was comparable between K. pneumoniae and vehicle-treated mice by 7 days. Examination of the fecal microbiome across a time course did not reveal any pronounced effects of either injury or K. pneumoniae on bacterial diversity or abundance. Together, these findings demonstrate that K. pneumoniae lung infection after TBI induces an acute and transient inflammatory response, primarily localized to the lungs with some systemic effects. However, this infection had minimal impact on secondary injury processes in the brain following TBI. Future studies are needed to evaluate the potential longer-term consequences of this dual-hit insult.

Experimental Models of Hospital-Acquired Infections After Traumatic Brain Injury: Challenges and Opportunities

Patients hospitalized after a moderate or severe traumatic brain injury (TBI) are at increased risk of nosocomial infections, including bacterial pneumonia and other upper respiratory tract infections. Infections represent a secondary immune challenge for vulnerable TBI patients that can lead to increased morbidity and poorer long-term prognosis. This review first describes the clinical significance of infections after TBI, delving into the known mechanisms by which a TBI can alter systemic immunological responses towards an immunosuppressive state, leading to promotion of increased vulnerability to infections. Pulmonary dysfunction resulting from respiratory tract infections is considered in the context of neurotrauma, including the bidirectional relationship between the brain and lungs. Turning to pre-clinical modeling, current laboratory approaches to study experimental TBI and lung infections are reviewed, to highlight findings from the limited key studies to date that have incorporated both insults. Then, practical decisions for the experimental design of animal studies of post-injury infections are discussed. Variables associated with the host animal, the infectious agent (e.g., species, strain, dose, and administration route), as well as the timing of the infection relative to the injury model are important considerations for model development. Together, the purpose of this review is to highlight the significant clinical need for increased pre-clinical research into the two-hit insult of a hospital-acquired infection after TBI to encourage further scientific enquiry in the field.

Machine learning algorithms for prediction of ventilator associated pneumonia in traumatic brain injury patients from the MIMIC-III database

BACKGROUND

Ventilator associated pneumonia (VAP) is a common complication and associated with poor prognosis of traumatic brain injury (TBI) patients.

OBJECTIVES

This study was conducted to explore the predictive performance of different machine-learning algorithms for VAP in TBI patients.

METHODS

TBI patients receiving mechanical ventilation more than 48 hours from the Medical Information Mart for Intensive Care-III (MIMIC-III) database were eligible for the study. The VAP was confirmed based on the ICD-9 code. Included patients were separated to the training cohort and the validation cohort with a ratio of 7:3. Predictive models based on different machine learning algorithms were developed using 5-fold cross validation in the training cohort and then verified in the validation cohort by evaluating the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, accuracy and F score.

RESULTS

786 TBI patients from the MIMIC-III were finally included with the VAP incidence of 44.0%. The random forest performed the best on predicting VAP in the training cohort with a AUC of 1.000. The XGBoost and AdaBoost were ranked the second and the third with a AUC of 0.915 and 0.789 in the training cohort. While the AdaBoost performed the best on predicting VAP in the validation cohort with a AUC of 0.706. The XGBoost and random forest were ranked the second and the third with the AUC of 0.685 and 0.683 in the validation cohort. Generally, the random forest and XGBoost were likely to be over-fitting while the AdaBoost was relatively stable in predicting the VAP.

CONCLUSIONS

The AdaBoost performed well and stably on predicting the VAP in TBI patients. Developing programs using AdaBoost in portable electronic devices may effectively assist physicians in assessing the risk of VAP in TBI.

Pneumonia in Nervous System Injuries: An Analytic Review of Literature and Recommendations

Pneumonia is one of the most common complications in intensive care units and is the most common nosocomial infection in this setting. Patients with neurocritical conditions who are admitted to ICUs are no exception, and in fact, are more prone to infections such as pneumonia because of factors such as swallow dysfunction, need for mechanical ventilation, longer length of stay in hospitals, etc. Common central nervous system pathologies such as ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage, neuromuscular disorders, status epilepticus, and demyelinating diseases can cause long in-hospital admissions and increase the risk of pneumonia each with a mechanism of its own. Brain injury-induced immunosuppression syndrome is usually considered the common mechanism through which patients with critical central nervous system conditions become susceptible to different kinds of infection including pneumonia. Evaluating the patients and assessment of the risk factors can lead our attention toward better infection control in this population and therefore decrease the risk of infections in central nervous system injuries.

Inflammation and the role of infection: Complications and treatment options following neurotrauma

Traumatic brain injury can have devastating consequences for patients and extended hospital stays and recovery course. Recent data indicate that the initial insult causes profound changes to the immune system and leads to a pro-inflammatory state. This alteration in homeostasis predisposes patients to an increased risk of infection and underlying autoimmune conditions. Increased emphasis has been placed on understanding this process both in the clinical and preclinical literature. This review highlights the intrinsic inflammatory conditions that can occur within the initial hospital stay, discusses long-term immune consequences, highlights emerging treatment options, and delves into important pathways currently being investigated with preclinical models.

Bacterial profile and their antimicrobial susceptibility patterns in patients admitted at MaddaWalabu University Goba Referral Hospital, Ethiopia: a cross sectional study

BACKGROUND

Hospital acquired infections (HAIs) are one of the global concerns in resource limited settings. The aim of the study was to determine bacteria profile and their antimicrobial susceptibility patterns among patients admitted at surgical and medical wards.

METHODS

A hospital based cross-sectional study was conducted from November 2016 to July 2017 in MaddaWalabu University Goba Referral Hospital. Urine and wound swabs were processed and standard disk diffusion test was done to assess susceptibility pattern. Association among variables was determined by Chi-square test.

RESULTS

Among 207 patients enrolled, 24.6% developed HAI, of which, 62.7% and 37.3% were from surgical and medical wards, respectively. The male to female ratio was 1.5:1. The age ranged from 19 to 74 years with a mean of 41.65(±16.48) years. A total 62 bacteria were isolated in which majority of the isolates were gram negative bacteria. Most isolates were resistance to most of the antibiotics tested but sensitive to Ceftriaxone, Norfloxacin and Ciprofloxacin.

CONCLUSION

Due to the presence of high level drug resistant bacteria, empirical treatment to HAI may not be effective. Therefore, treatment should be based on the result of culture and sensitivity.

Effects of hospital-acquired pneumonia on long-term recovery and hospital resource utilization following moderate to severe traumatic brain injury

BACKGROUND

Individuals with traumatic brain injury (TBI) have extended inpatient hospital stays that include prolonged mechanical ventilation, increasing risk for infections, including pneumonia. Studies show the negative short-term effects of hospital-acquired pneumonia (HAP) on hospital-based outcomes; however, little is known of its long-term effects.

METHODS

A prospective cohort study was conducted. National Trauma Databank and Traumatic Brain Injury Model Systems were merged to derive a cohort of 3,717 adults with moderate-to-severe TBI. Exposure data were gathered from the National Trauma Databank, and outcomes were gathered from the Traumatic Brain Injury Model Systems. The primary outcome was the Glasgow Outcome Scale-Extended (GOS-E), which was collected at 1, 2, and 5 years postinjury. The GOS-E was categorized as favorable (>5) or unfavorable (≤5) outcomes. A generalized estimating equation model was fitted estimating the effects of HAP on GOS-E over the first 5 years post-TBI, adjusting for age, race, ventilation status, brain injury severity, injury severity score, thoracic Abbreviated Injury Scale score of 3 or greater, mechanism of injury, intraventricular hemorrhage, and subarachnoid hemorrhage.

RESULTS

Individuals with HAP had a 34% (odds ratio, 1.34; 95% confidence interval, 1.15-1.56) increased odds for unfavorable GOS-E over the first 5 years post-TBI compared with individuals without HAP, after adjustment for covariates. There was a significant interaction between HAP and follow-up, such that the effect of HAP on GOS-E declined over time. Sensitivity analyses that weighted for nonresponse bias and adjusted for differences across trauma facilities did not appreciably change the results. Individuals with HAP spent 10.1 days longer in acute care and 4.8 days longer in inpatient rehabilitation and had less efficient functional improvement during inpatient rehabilitation.

CONCLUSION

Individuals with HAP during acute hospitalization have worse long-term prognosis and greater hospital resource utilization. Preventing HAP may be cost-effective and improve long-term recovery for individuals with TBI. Future studies should compare the effectiveness of different prophylaxis methods to prevent HAP.

LEVEL OF EVIDENCE

Prospective cohort study, level III.

Pneumonia in acute ischemic stroke patients requiring invasive ventilation: Impact on short and long-term outcomes

OBJECTIVES

To describe the epidemiology and prognostic impact of pneumonia in acute ischemic stroke patients requiring invasive mechanical ventilation.

METHODS

Retrospective analysis from a prospective multicenter cohort study of critically ill patients with acute ischemic stroke requiring invasive mechanical ventilation at admission. Impact of pneumonia was investigated using Cox regression for 1-year mortality, and competing risk survival models for ICU mortality censored at 30-days.

RESULTS

We included 195 patients. Stroke was supratentorial in 62% and 64% of patients had a Glasgow coma scale score <8 on admission. Mortality at day-30 and 1 year were 56%, and 70%, respectively. Post-stroke pneumonia was identified in 78 (40%) patients, of which 46/78 (59%) episodes were present at ICU admission. Post-stroke pneumonia was associated with an increase in 1-year mortality (adjusted HR 1.49, 95%CI [1.01-2.20]). Post-stroke pneumonia was not associated with ICU mortality but was associated with a 1.6-fold increase in ICU length of stay (CSHR 0.62 [0.39-0.99], p = 0.06).

CONCLUSIONS

In ischemic stroke patients requiring invasive ventilation, pneumonia occurred in 40% of cases and was associated with a 49% increase in 1-year mortality. Post-stroke pneumonia did not impact day-30 mortality but increased ICU length of stay.

The economic cost of stroke-associated pneumonia in a UK setting

Introduction Stroke-associated pneumonia (SAP) is common, however, data on the economic impact of SAP are scarce. This study aimed to prospectively evaluate the impact of SAP on acute stroke care costs in a UK setting. Methods Prospective cohort study of 213 consecutive patients with stroke (196 ischemic, 17 hemorrhagic) was admitted to a UK hospital over 1 year. Socio demographic and clinical characteristics were recorded along with all treatments and rehabilitation activity. Patients were classified as having SAP if they fulfilled criteria for "probable" or "definite" respiratory tract infection according to the Centres for Disease Control and Prevention definition, within the first seven days following stroke. Resource use was calculated using a "bottom up" approach of cumulative unit costs. Univariate and multivariate regression analyses were used to establish independent predictors of direct costs. Results Probable or definite SAP occurred in 13.2% (28/213) of patients. Patients with SAP experienced greater inpatient stays (31 days vs. 9 days, p ≤ 0.001) and higher in-hospital mortality (29.2% vs. 10.2%, p = 0.007). Mean (SD) acute care costs per patient was £7035 (6767), but costs were significantly greater for patients with SAP than without [£14,371 (9484) versus £6,103 (5,735); p ≤ 0.001]. SAP was an independent predictor of costs along with increasing stroke severity (NIHSS) and age. Occurrence of SAP resulted in an adjusted incremental additional cost of £5817 (95% CI 4945-6689; p = 0.001) per patient. Conclusions SAP increased acute care costs for stroke by approximately 80%. This provides further impetus for research aimed at reducing SAP, and will inform cost-effectiveness analyses of potential therapeutic strategies.

Risk factors for hospital-acquired infections in teaching hospitals of Amhara regional state, Ethiopia: A matched-case control study

Background

Hospital-acquired infection affects hundreds of millions of people worldwide. It is a major global issue for patient safety. Understanding the potential risk factors is important to appreciate the local context. A matched case control study design, which is the first of its kind in the study region, was undertaken to identify risk factors in teaching hospitals of Amhara regional state, Ethiopia.

Method

A matched case control study design matched with age and hospital type was used. The study was conducted in University of Gondar and Felege-Hiwot medical teaching hospital. Cases were patients who fulfilled the criteria based on CDC definition of hospital-acquired infection and controls were patients admitted to the hospital that stayed for more than 48 hours in the ward in the study period, but who did not develop infection. For one case, four controls were selected. Of 545 patients, 109 were cases and 436 were controls. Conditional logistic regression using STATA 13 was used for data analysis.

Result

The median length of stay for cases and controls was 7 and 8 days, respectively. Patients admitted in wards with the presence of medical waste container in the room had 82% less chance of developing hospital-acquired infection (AOR 0.18; 95% CI, 0.03–0.98). The odds of developing hospital-acquired infection among immune deficient patients were 2.34 times higher than their counterparts (95% CI; 1.17–4.69). Patients received antimicrobials, central vascular catheter and surgery since admission had 8.63, 6.91 and 2.35 higher odds of developing hospital-acquired infection, respectively.

Conclusion

Health providers and mangers should consider the provision and availability of healthcare materials and facilities in all of the ward rooms, follow appropriate safe medical procedures for use of external devices on patients, and give attention to the immunocompromised patients for the prevention and control of hospital-acquired infections.

Decreasing incidence and mortality among hospitalized patients suffering a ventilator-associated pneumonia: Analysis of the Spanish national hospital discharge database from 2010 to 2014

The aim of this study was to describe trends in the incidence and outcomes of ventilator-associated pneumonia (VAP) among hospitalized patients in Spain (2010-2014).This is a retrospective study using the Spanish national hospital discharge database from year 2010 to 2014. We selected all hospital admissions that had an ICD-9-CM code: 997.31 for VAP in any diagnosis position. We analyzed incidence, sociodemographic and clinical characteristics, procedures, pathogen isolations, and hospital outcomes.We identified 9336 admissions with patients suffering a VAP. Incidence rates of VAP decreased significantly over time (from 41.7 cases/100,000 inhabitants in 2010 to 40.55 in 2014). The mean Charlson comorbidity index (CCI) was 1.08 ± 0.98 and it did not change significantly during the study period. The most frequent causative agent was Pseudomonas and there were not significant differences in the isolation of this microorganism over time. Time trend analyses showed a significant decrease in in-hospital mortality (IHM), from 35.74% in 2010 to 32.81% in 2014. Factor associated with higher IHM included male sex, older age, higher CCI, vein or artery occlusion, pulmonary disease, cancer, undergone surgery, emergency room admission, and readmission.This study shows that the incidence of VAP among hospitalized patients has decreased in Spain from 2010 to 2014. The IHM has also decreased over the study period. Further investigations are needed to improve the prevention and control of VAP.

Incidence, characteristic and outcomes of ventilator-associated pneumonia among type 2 diabetes patients: An observational population-based study in Spain

BACKGROUND

To describe incidence, characteristics and outcomes of ventilator-associated pneumonia (VAP) during hospitalization among patients with or without type 2 diabetes (T2DM).

METHODS

We used the Spanish national hospital discharge database to select all hospitalization with VAP in subjects aged 40years or more from 2010 to 2014. We analyzed incidence, patient comorbidities, procedures, pneumonia pathogens and in-hospital outcomes according to diabetes status (T2DM and no-diabetes). We used propensity score analysis to estimate the effect of T2DM on in-hospital mortality RESULTS: In 7952 admissions, the patient developed a VAP (13.6% with T2DM). Adjusted incidence rate of VAP was slightly, but significantly, higher in T2DM than in non-diabetic patients (36.46[95% CI 34.41-38.51] vs. 32.57[95% CI 31.40-33.74] cases per 100,000/inhabitants). T2DM people were older and had higher Charlson comorbidity index than non-diabetic people. T2DM patients had a lower mean number of failing organs than non-diabetic patients (1.20 SD 1.17 vs. 1.45 SD 1.44, p<0.001). Pseudomonas was the most frequently isolated agent in both groups. IHM was 41.92% for T2DM patients and 37.91% for non-diabetic patients (p<0.05). Factors associated with a higher mortality in both groups included: older age, more comorbidities and primary diagnoses of vein or artery occlusion, pulmonary disease and cancer. T2DM was not associated with a higher in-hospital mortality after adjustment using a propensity score (OR 0.88; 95% CI 0.76-1.35).

CONCLUSIONS

VAP incidence rates were higher among T2DM patients. In-hospital mortality was higher among the older patients and those with more co-morbid conditions. T2DM does not predict higher mortality in VAP during hospitalization.

Risk factors for ventilator-associated pneumonia: among trauma patients with and without brain injury

Ventilator-associated pneumonia (VAP) rates remain highest among trauma and brain injured patients; yet, no research compares VAP risk factors between the 2 groups. This retrospective, case-controlled study identified risk factors for VAP among critically ill trauma patients with and without brain injury. Data were abstracted on trauma patients with (cases) and without (controls) brain injury. Data gathered on n = 157 subjects. Trauma patients with brain injury had more emergent and field intubations. Age was strongest predictor of VAP in cases, and ventilator days predicted VAP in controls. Trauma patients with brain injury may be at higher risk for VAP.

Prolonged mechanical ventilation is associated with pulmonary complications, increased length of stay, and unfavorable discharge destination among patients with subdural hematoma

BACKGROUND

Although subdural hematoma (SDH) is common in neurocritical practice, little is known about SDH patients requiring prolonged mechanical ventilation (PMV). We aimed to determine predictors of PMV and its relationship with outcome in patients with SDH.

METHODS

SDH patients admitted to Rush University neurointensive care unit from January 2009 to March 2012 were reviewed. Duration of intubation, pulmonary complications, demographics, treatment, discharge disposition, and length of stay (LOS) were reviewed. PMV was defined as duration of intubation >4 days. Univariate and multivariate analyses were performed to identify predictors of PMV and association with outcome among survivors with SDH.

RESULTS

Of the 288 survivors with SDH, the mean age was 68, and of them 179 were male. A total of 137 required surgical SDH evacuation. Pneumonia occurred in 26 patients. Forty-eight patients (17%) required intubation, with duration of intubation being 1 to 20 days (median 3.0). Factors independently associated with PMV included alcohol abuse (OR, 4.31; 95% CI, 1.36-13.67), admission GCS<15 (OR, 11; 95% CI, 2.36-51.52), and surgical evacuation (OR, 9.27; 95% CI, 1.93-44.54). PMV predicted pneumonia (OR, 5.85; 95% CI, 1.52-22.57), tracheostomy (OR, 26.67; 95% CI, 2.93-242.67), increased LOS, and unfavorable discharge destination (OR, 73.1; 95% CI, 14.03-380.69).

CONCLUSIONS

PMV is associated with pulmonary complications, increased LOS, and unfavorable discharge destination in patients with SDH. Alcohol abuse, admission GCS, and surgical evacuation are associated with PMV among patients with SDH. Future studies should investigate the role of early tracheostomy in high-risk patients and impact on outcomes.

To Trach or Not to Trach: Uncertainty in the Care of the Chronically Critically Ill

The number of chronically critically ill patients requiring prolonged mechanical ventilation and receiving a tracheostomy is steadily increasing. Early tracheostomy in patients requiring prolonged mechanical ventilation has been proposed to decrease duration of mechanical ventilation and intensive care unit stay, reduce mortality, and improve patient comfort. However, these benefits have been difficult to demonstrate in clinical trials. So how does one determine the appropriate timing for tracheostomy placement in your patient? Here we review the potential benefits and consequences of tracheostomy, the available evidence for tracheostomy timing, communication surrounding the tracheostomy decision, and a patient-centered approach to tracheostomy. Patients requiring > 10 days of mechanical ventilation who are expected to survive their hospitalization likely benefit from tracheostomy, but protocols involving routine early tracheostomy placement do not improve patient outcomes. However, patients with neurologic injury, provided they have a good prognosis for meaningful recovery, may benefit from early tracheostomy. In chronically critically ill patients with poor prognosis, tracheostomy is unlikely to provide benefit and should only be pursued if it is consistent with the patient's values, goals, and preferences. In this setting, communication with patients and surrogates regarding tracheostomy and prognosis becomes paramount. For the foreseeable future, decisions surrounding tracheostomy will remain relevant and challenging.

International multidisciplinary consensus conference on multimodality monitoring: ICU processes of care

There is an increased focus on evaluating processes of care, particularly in the high acuity and cost environment of intensive care. Evaluation of neurocritical-specific care and evidence-based protocol implementation are needed to effectively determine optimal processes of care and effect on patient outcomes. General quality measures to evaluate intensive care unit (ICU) processes of care have been proposed; however, applicability of these measures in neurocritical care populations has not been established. A comprehensive literature search was conducted for English language articles from 1990 to August 2013. A total of 1,061 articles were reviewed, with 145 meeting criteria for inclusion in this review. Care in specialized neurocritical care units or by neurocritical teams can have a positive impact on mortality, length of stay, and in some cases, functional outcome. Similarly, implementation of evidence-based protocol-directed care can enhance outcome in the neurocritical care population. There is significant evidence to support suggested quality indicators for the general ICU population, but limited research regarding specific use in neurocritical care. Quality indices for neurocritical care have been proposed; however, additional research is needed to further validate measures.

A 2015 Update on Ventilator-Associated Pneumonia: New Insights on Its Prevention, Diagnosis, and Treatment

Ventilator-associated pneumonia (VAP), an infection of the lower respiratory tract which occurs in association with mechanical ventilation, is one of the most common causes of nosocomial infection in the intensive care unit (ICU). VAP causes significant morbidity and mortality in critically ill patients including increased duration of mechanical ventilation, ICU stay and hospitalization. Current knowledge for its prevention, diagnosis and management is therefore important clinically and is the basis for this review. We discuss recent changes in VAP surveillance nomenclature incorporating ventilator-associated conditions and ventilator-associated events, terms recently proposed by the Centers for Disease Control. To the extent possible, we rely predominantly on data from randomized control trials (RCTs) and meta-analyses.

Substance P mediates reduced pneumonia rates after traumatic brain injury

OBJECTIVES

Traumatic brain injury results in significant morbidity and mortality and is associated with infectious complications, particularly pneumonia. However, whether traumatic brain injury directly impacts the host response to pneumonia is unknown. The objective of this study was to determine the nature of the relationship between traumatic brain injury and the prevalence of pneumonia in trauma patients and investigate the mechanism of this relationship using a murine model of traumatic brain injury with pneumonia.

DESIGN

Data from the National Trauma Data Bank and a murine model of traumatic brain injury with postinjury pneumonia.

SETTING

Academic medical centers in Cincinnati, OH, and Boston, MA.

PATIENTS/SUBJECTS

Trauma patients in the National Trauma Data Bank with a hospital length of stay greater than 2 days, age of at least 18 years at admission, and a blunt mechanism of injury. Subjects were female ICR mice 8-10 weeks old.

INTERVENTIONS

Administration of a substance P receptor antagonist in mice.

MEASUREMENTS AND MAIN RESULTS

Pneumonia rates were measured in trauma patients before and after risk adjustment using propensity scoring. In addition, survival and pulmonary inflammation were measured in mice undergoing traumatic brain injury with or without pneumonia. After risk adjustment, we found that traumatic brain injury patients had significantly lower rates of pneumonia compared to blunt trauma patients without traumatic brain injury. A murine model of traumatic brain injury reproduced these clinical findings with mice subjected to traumatic brain injury demonstrating increased bacterial clearance and survival after induction of pneumonia. To determine the mechanisms responsible for this improvement, the substance P receptor was blocked in mice after traumatic brain injury. This treatment abrogated the traumatic brain injury-associated increases in bacterial clearance and survival.

CONCLUSIONS

The data demonstrate that patients with traumatic brain injury have lower rates of pneumonia compared to non-head-injured trauma patients and suggest that the mechanism of this effect occurs through traumatic brain injury-induced release of substance P, which improves innate immunity to decrease pneumonia.

Effect of oropharyngeal povidone-iodine preventive oral care on ventilator-associated pneumonia in severely brain-injured or cerebral hemorrhage patients: a multicenter, randomized controlled trial

OBJECTIVE

To evaluate the efficacy and safety of oral care with povidone-iodine on the occurrence of ventilator-associated pneumonia in a high-risk population.

DESIGN

A multicenter, placebo-controlled, randomized, double-blind, two-parallel-group trial performed between May 2008 and May 2011.

SETTING

Six ICUs in France.

PATIENTS

One hundred seventy-nine severely brain-injured patients (Glasgow Coma Scale ≤ 8) or cerebral hemorrhage expected to be mechanically ventilated for more than 24 hours.

INTERVENTIONS

Participants were randomly assigned to receive oropharyngeal care with povidone-iodine (n = 91) or placebo (n = 88) six times daily until mechanical ventilation withdrawal.

MEASUREMENTS AND MAIN RESULTS

Primary endpoint was the rate of ventilator-associated pneumonia. Secondary endpoint included the rates of ventilator-associated tracheobronchitis and acute respiratory distress syndrome and patient's outcome. The number of patients evaluable for the primary endpoint (preplanned modified intention-to-treat population) was 150 (78 in the povidone-iodine group, 72 in the placebo group). Ventilator-associated pneumonia occurred in 24 patients (31%) in the povidone-iodine group and 20 (28%) in the placebo group (relative risk, 1.11 [95% CI, 0.67-1.82]; p = 0.69). There was no significant difference between the two groups for ventilator-associated tracheobronchitis: eight patients (10%) in the povidone-iodine group and five patients (7%) in the placebo group (relative risk, 1.48 [95% CI, 0.51-4.31]; p = 0.47). Acute respiratory distress syndrome occurred in five patients in the povidone-iodine group but not in the placebo group (p = 0.06). There was no difference between groups for ICU and hospital lengths of stay, as well as ICU and 90-day mortality.

CONCLUSIONS

There is no evidence to recommend oral care with povidone-iodine to prevent ventilator-associated pneumonia in high-risk patients. Furthermore, this strategy seems to increase the rate of acute respiratory distress syndrome.

Stroke-associated pneumonia: major advances and obstacles

BACKGROUND

Stroke-associated pneumonia (SAP) has been implicated in the morbidity, mortality and increased medical cost after acute ischemic stroke. The annual cost of SAP during hospitalization in the United States approaches USD 459 million. The incidence and prognosis of SAP among intensive care unit (ICU) patients have not been thoroughly investigated. We reviewed the pathophysiology, microbiology, incidence, risk factors, outcomes and prophylaxis of SAP with special attention to ICU studies.

METHODS

To determine the incidence, risk factors and prognosis of acute SAP, PubMed was searched using the terms 'pneumonia' AND 'neurology intensive unit' and the MeSH terms 'stroke' AND 'pneumonia'. Non-English literature, case reports and chronic SAP studies were excluded. Studies were classified into 5 categories according to the setting they were performed in: neurological intensive care units (NICUs), medical intensive care units (MICUs), stroke units, mixed studies combining more than one setting or when the settings were not specified and rehabilitation studies.

RESULTS

The incidences of SAP in the following settings were: NICUs 4.1-56.6%, MICUs 17-50%, stroke units 3.9-44%, mixed studies 3.9-23.8% and rehabilitation 3.2-11%. The majority of NICU and MICU studies were heterogeneous including different neurovascular diseases, which partly explains the wide range of SAP incidence. The higher incidence in the majority of ICU studies compared to stroke units or acute floor studies is likely explained by the presence of mechanical ventilation, higher stroke severity causing higher rates of aspiration and stroke-induced immunodepression among ICU patients. The short-term mortality of SAP was increased among the mixed and stroke unit studies ranging between 10.1 and 37.3%. SAP was associated with worse functional outcome in the majority of stroke unit and floor studies. Mortality was less consistent among NICU and MICU studies. This difference could be due to the heterogeneity of ICU studies and the effect of small sample size or other independent risk factors for mortality such as the larger neurological deficit, mechanical ventilation, and age, which may simultaneously increase the risk of SAP and mortality confounding the outcomes of SAP itself. The pathophysiology of SAP is likely explained by aspiration combined with stroke-induced immunodepression through complex humeral and neural pathways that include the hypothalamic-pituitary-adrenal axis, parasympathetic and sympathetic systems.

CONCLUSIONS

A unified definition of SAP, strict inclusion criteria, and the presence of a long-term follow-up need to be applied to the future prospective studies to better identify the incidence and prognosis of SAP, especially among ICU patients.