Influence on outcome of ventilator-associated pneumonia in multiple trauma patients with head trauma treated with selected digestive decontamination

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.

Rebound Inverts the Staphylococcus aureus Bacteremia Prevention Effect of Antibiotic Based Decontamination Interventions in ICU Cohorts with Prolonged Length of Stay

Could rebound explain the paradoxical lack of prevention effect against Staphylococcus aureus blood stream infections (BSIs) with antibiotic-based decontamination intervention (BDI) methods among studies of ICU patients within the literature? Two meta-regression models were applied, each versus the group mean length of stay (LOS). Firstly, the prevention effects against S. aureus BSI [and S. aureus VAP] among 136 studies of antibiotic-BDI versus other interventions were analyzed. Secondly, the S. aureus BSI [and S. aureus VAP] incidence in 268 control and intervention cohorts from studies of antibiotic-BDI versus that among 165 observational cohorts as a benchmark was modelled. In model one, the meta-regression line versus group mean LOS crossed the null, with the antibiotic-BDI prevention effect against S. aureus BSI at mean LOS day 7 (OR 0.45; 0.30 to 0.68) inverted at mean LOS day 20 (OR 1.7; 1.1 to 2.6). In model two, the meta-regression line versus group mean LOS crossed the benchmark line, and the predicted S. aureus BSI incidence for antibiotic-BDI groups was 0.47; 0.09-0.84 percentage points below versus 3.0; 0.12-5.9 above the benchmark in studies with 7 versus 20 days mean LOS, respectively. Rebound within the intervention groups attenuated and inverted the prevention effect of antibiotic-BDI against S. aureus VAP and BSI, respectively. This explains the paradoxical findings.

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.

Incidence, Risk Factors, and Outcomes of Ventilator-Associated Pneumonia in Traumatic Brain Injury: A Meta-analysis

Ventilator-associated pneumonia (VAP) is one of the most severe complications in patients with traumatic brain injury (TBI) and is considered a risk factor for poor outcomes. However, the incidence of VAP among patients with TBI reported in studies varies widely. What is more, the risk factors and outcomes of VAP are controversial. This study estimates the incidence, risk factors, and outcomes of VAP in patients with TBI and provides evidence for prevention and treatment. PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched from the earliest records to May 2018. Data involving the incidence, risk factors, and outcomes were extracted for meta-analysis. The results showed that the incidence of VAP was 36% (95% confidence interval (CI) 31-41%); risk factors analyses showed that smoking [odds ratio (OR) 2.13; 95% CI 1.16-3.92], tracheostomy (OR 9.55; 95% CI 3.24-28.17), blood transfusion on admission (OR 2.54; 95% CI 1.24-5.18), barbiturate infusion (OR 3.52; 95% CI 1.68-7.40), injury severity score (OR 4.65; 95% CI 1.96-7.34), and head abbreviated injury scale (OR 2.99; 95% CI 1.66-5.37) were related to the occurrence of VAP. When patients developed VAP, mechanical ventilation time (OR 5.45; 95% CI 3.78-7.12), ICU length of stay (OR 6.85; 95% CI 4.90-8.79), and hospital length of stay (OR 10.92; 95% CI 9.12-12.72) were significantly increased. However, VAP was not associated with an increased risk of mortality (OR 1.28; 95% CI 0.74-2.21). VAP is common in patients with TBI. It is affected by a series of factors and has a poor prognosis.

The effect of sedation and/or analgesia as rescue treatment during noninvasive positive pressure ventilation in the patients with Interface intolerance after Extubation

Background

Sedation and/or analgesia can relieve the patient-ventilator asynchrony. However, whether sedation and/or analgesia can benefit the clinical outcome of the patients with interface intolerance is still unclear.

Methods

A retrospective study was performed on patients with interface intolerance who received noninvasive positive pressure ventilation (NIPPV) after extubation in seven intensive care units (ICU) of West China Hospital, Sichuan University. The primary outcome was rate of NIPPV failure (defined as need for reintubation and mechanical ventilation); Secondary outcomes were hospital mortality rate and length of ICU stay after extubation.

Results

A total of 80 patients with oral-nasal mask (90%) and facial mask (10%) were included in the analysis. 41 out of 80 patients received sedation and/or analgesia treatment (17 used analgesia, 11 used sedation and 13 used both) at some time during NIPPV. They showed a decrease of NIPPV failure rate, (15% vs. 38%, P = 0.015; adjusted odd ratio [OR] 0.29, 95% confidence interval [CI] 0.10–0.86, P = 0.025), mortality rate (7% vs. 33%, P = 0.004; adjusted OR 0.14, 95% CI 0.03–0.60, P = 0.008), and the length of ICU stay after extubation.

Conclusion

This clinical study suggests that sedation and/or analgesia treatment can decrease the rate of NIPPV failure, hospital mortality rate and ICU LOS in patients with interface intolerance after extubution during NIPPV.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0469-4) contains supplementary material, which is available to authorized users.

The effect of high-flow nasal cannula in reducing the mortality and the rate of endotracheal intubation when used before mechanical ventilation compared with conventional oxygen therapy and noninvasive positive pressure ventilation. A systematic review and meta-analysis

BACKGROUND

The effects of high flow nasal cannula (HFNC) on adult patients when used before mechanical ventilation (MV) are unclear. We aimed to determine the effectiveness of HFNC when used before MV by comparison to conventional oxygen therapy (COT) and noninvasive positive pressure ventilation (NIPPV).

METHODS

The Pubmed, Embase, Medline, Cochrane Central Register of Controlled Trials (CENTRAL) as well as the Information Sciences Institute (ISI) Web of Science were searched for all the controlled studies that compared HFNC with NIPPV and COT when used before MV in adult patients. The primary outcome was the rate of endotracheal intubation and the secondary outcomes were intensive care unit (ICU) mortality and length of ICU stay (ICU LOS).

RESULTS

Eight trials with a total of 1084 patients were pooled in our final studies. No significant heterogeneity was found in outcome measures. Compared both with COT and NIPPV, HFNC could reduce both of the rate of endotracheal intubation (OR 0.62, 95% CI 0.38-0.99, P=0.05; OR 0.48, 95% CI 0.31-0.73, P=0.0006) and ICU mortality (OR 0.47, 95% CI 0.24-0.93, P=0.03; OR 0.36, 95% CI 0.20-0.63, P=0.0004). As for the ICU LOS, we did not find any advantage of HFNC over COT or NIPPV.

CONCLUSIONS

When used before MV, HFNC can improve the prognosis of patients compared both with the COT and NIPPV.

Acute brain trauma, lung injury, and pneumonia: more than just altered mental status and decreased airway protection

Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. Even when patients survive the initial insult, there is significant morbidity and mortality secondary to subsequent pulmonary edema, acute lung injury (ALI), and nosocomial pneumonia. Whereas the relationship between TBI and secondary pulmonary complications is recognized, little is known about the mechanistic interplay of the two phenomena. Changes in mental status secondary to acute brain injury certainly impair airway- and lung-protective mechanisms. However, clinical and translational evidence suggests that more specific neuronal and cellular mechanisms contribute to impaired systemic and lung immunity that increases the risk of TBI-mediated lung injury and infection. To better understand the cellular mechanisms of that immune impairment, we review here the current clinical data that support TBI-induced impairment of systemic and lung immunity. Furthermore, we also review the animal models that attempt to reproduce human TBI. Additionally, we examine the possible role of damage-associated molecular patterns, the chlolinergic anti-inflammatory pathway, and sex dimorphism in post-TBI ALI. In the last part of the review, we discuss current treatments and future pharmacological therapies, including fever control, tracheostomy, and corticosteroids, aimed to prevent and treat pulmonary edema, ALI, and nosocomial pneumonia after TBI.

Hospital-acquired pneumonia is an independent predictor of poor global outcome in severe traumatic brain injury up to 5 years after discharge

BACKGROUND

Long-term outcomes following traumatic brain injury (TBI) correlate with initial head injury severity and other acute factors. Hospital-acquired pneumonia (HAP) is a common complication in TBI. Limited information exists regarding the significance of infectious complications on long-term outcomes after TBI. We sought to characterize risks associated with HAP on outcomes 5 years after TBI.

METHODS

This study involved data from the merger of an institutional trauma registry and the Traumatic Brain Injury Model Systems outcome data. Individuals with severe head injuries (Abbreviated Injury Scale [AIS] score ≥ 4) who survived to rehabilitation were analyzed. Primary outcome was Glasgow Outcome Scale-Extended (GOSE) at 1, 2, and 5 years. GOSE was dichotomized into low (GOSE score < 6) and high (GOSE score ≥ 6). Logistic regression was used to determine adjusted odds of low GOSE score associated with HAP after controlling for age, sex, head and overall injury severity, cranial surgery, Glasgow Coma Scale (GCS) score, ventilation days, and other important confounders. A general estimating equation model was used to analyze all outcome observations simultaneously while controlling for within-patient correlation.

RESULTS

A total of 141 individuals met inclusion criteria, with a 30% incidence of HAP. Individuals with and without HAP had similar demographic profiles, presenting vitals, head injury severity, and prevalence of cranial surgery. Individuals with HAP had lower presenting GCS score. Logistic regression demonstrated that HAP was independently associated with low GOSE scores at follow-up (1 year: odds ratio [OR], 6.39; 95% confidence interval [CI], 1.76-23.14; p = 0.005) (2 years: OR, 7.30; 95% CI, 1.87-27.89; p = 0.004) (5-years: OR, 6.89; 95% CI, 1.42-33.39; p = 0.017). Stratifying by GCS score of 8 or lower and early intubation, HAP remained a significant independent predictor of low GOSE score in all strata. In the general estimating equation model, HAP continued to be an independent predictor of low GOSE score (OR, 4.59; 95% CI, 1.82-11.60; p = 0.001).

CONCLUSION

HAP is independently associated with poor outcomes in severe TBI extending 5 years after injury. This suggests that precautions should be taken to reduce the risk of HAP in individuals with severe TBI.

LEVEL OF EVIDENCE

Prognostic study, level III.

Impact of ventilator associated pneumonia on outcome in patients with chronic obstructive pulmonary disease exacerbation

Background and Objective:

There are sparse data regarding the impact of ventilator-associated pneumonia (VAP) on outcome among patients with chronic obstructive pulmonary disease (COPD) exacerbation.

Materials and Methods:

This retrospective study included patients with COPD exacerbation requiring endotracheal intubation for more than 48 h admitted in a single respiratory unit from January 2008 to December 2009. Records of these patients were checked for the occurrence of VAP.

Results:

One hundred and fifty-three patients required endotracheal intubation for COPD exacerbation during this period. The mean age of this cohort was 61.46 ± 11.3 years. The median duration of COPD was 6 years (range: 1-40). A total of 35 (22.8%) patients developed VAP (early: 9 and late: 26). The risk of mortality was comparable between two groups, that is, patients with and without VAP [odd's ratio (OR)−1.125; 95% confidence interval (CI), 0.622-2.035]. The duration of mechanical ventilation and hospital stay (median ± standard error, 95% CI) was 32 ± 10 (95% CI, 13-51) versus 10 ± 2 (95% CI, 6-14) days; P ≤ 0.001 and 53 ± 26 (95% CI, 3-103) versus 18 ± 7 (95% CI, 5-31) days; P = 0.031, respectively was higher among patients with VAP.

Conclusions:

Our study has shown that VAP leads to increased duration of mechanical ventilation and hospital stay; however, the mortality is not affected.

Effect of selective decontamination on antimicrobial resistance in intensive care units: a systematic review and meta-analysis

BACKGROUND

Many meta-analyses have shown reductions in infection rates and mortality associated with the use of selective digestive decontamination (SDD) or selective oropharyngeal decontamination (SOD) in intensive care units (ICUs). These interventions have not been widely implemented because of concerns that their use could lead to the development of antimicrobial resistance in pathogens. We aimed to assess the effect of SDD and SOD on antimicrobial resistance rates in patients in ICUs.

METHODS

We did a systematic review of the effect of SDD and SOD on the rates of colonisation or infection with antimicrobial-resistant pathogens in patients who were critically ill. We searched for studies using Medline, Embase, and Cochrane databases, with no limits by language, date of publication, study design, or study quality. We included all studies of selective decontamination that involved prophylactic application of topical non-absorbable antimicrobials to the stomach or oropharynx of patients in ICUs, with or without additional systemic antimicrobials. We excluded studies of interventions that used only antiseptic or biocide agents such as chlorhexidine, unless antimicrobials were also included in the regimen. We used the Mantel-Haenszel model with random effects to calculate pooled odds ratios.

FINDINGS

We analysed 64 unique studies of SDD and SOD in ICUs, of which 47 were randomised controlled trials and 35 included data for the detection of antimicrobial resistance. When comparing data for patients in intervention groups (those who received SDD or SOD) versus data for those in control groups (who received no intervention), we identified no difference in the prevalence of colonisation or infection with Gram-positive antimicrobial-resistant pathogens of interest, including meticillin-resistant Staphylococcus aureus (odds ratio 1·46, 95% CI 0·90-2·37) and vancomycin-resistant enterococci (0·63, 0·39-1·02). Among Gram-negative bacilli, we detected no difference in aminoglycoside-resistance (0·73, 0·51-1·05) or fluoroquinolone-resistance (0·52, 0·16-1·68), but we did detect a reduction in polymyxin-resistant Gram-negative bacilli (0·58, 0·46-0·72) and third-generation cephalosporin-resistant Gram-negative bacilli (0·33, 0·20-0·52) in recipients of selective decontamination compared with those who received no intervention.

INTERPRETATION

We detected no relation between the use of SDD or SOD and the development of antimicrobial-resistance in pathogens in patients in the ICU, suggesting that the perceived risk of long-term harm related to selective decontamination cannot be justified by available data. However, our study indicates that the effect of decontamination on ICU-level antimicrobial resistance rates is understudied. We recommend that future research includes a non-crossover, cluster randomised controlled trial to assess long-term ICU-level changes in resistance rates.

FUNDING

None.

Risk factors and outcomes for prolonged versus brief fever: a prospective cohort study

INTRODUCTION

Prolonged fever occurs with infectious and noninfectious diseases but is poorly studied in intensive care units. The aims of this prospective multicenter noninterventional study were to determine the incidence and etiologies of prolonged fever in critically ill patients and to compare outcomes for prolonged fever and short-lasting fever.

METHODS

The study involved two periods of 2 months each, with 507 patients hospitalized ≥ 24 hours. Fever was defined by at least one episode of temperature ≥ 38.3 °C, and prolonged fever, as lasting > 5 days. Backward stepwise logistic regression was performed to identify the independent factors associated with prolonged fever versus short-lasting fever.

RESULTS

Prolonged or short-lasting fever occurred in 87 (17%) and 278 (55%) patients, respectively. Infectious and noninfectious causes were found in 54 (62%) and 27 (31%) of 87 patients, respectively; in six patients (7%), prolonged fever remained unexplained. The two most common sites of infection were ventilator-associated pneumonia (n = 25) and intraabdominal infection (n = 13). Noninfectious fever (n = 27) was neurogenic in 19 (70%) patients and mainly associated with cerebral injury (84%). Independent risk factors for prolonged fever were cerebral injury at admission (OR = 5.03; 95% CI, 2.51 to 10.06), severe sepsis (OR = 2.79; 95% CI, 1.35 to 5.79), number of infections (OR = 2.35; 95% CI, 1.43 to 3.86), and mechanical-ventilation duration (OR = 1.05; 95% CI, 1.01 to 1.09). Older patients were less likely to develop prolonged fever. ICU mortality did not differ between the two groups.

CONCLUSIONS

Prolonged fever was common, mainly due to severe infections, particularly ventilator-associated pneumonia, and mixed infectious causes were frequent, warranting systematic and careful search for multiple causes. Neurogenic fever was also especially frequent.

Attributable mortality of ventilator-associated pneumonia

PURPOSE OF REVIEW

To critically discuss the attributable mortality of ventilator-associated pneumonia (VAP) and potential sources of variation.

RECENT FINDINGS

The review will cover the available estimates (0-50%). It will also explore the source of variation because of definition of VAP (being lower if inaccurate), case-mix issues (being lower for trauma patients), the severity of underlying illnesses (being maximal when the severity of underlying illness is intermediate), and on the characteristics and the severity of the VAP episode. Another important source of variation is the use of poorly appropriate statistical models (estimates biased by lead time bias and competing events). New extensions of survival models which take into account the time dependence of VAP occurrence and competing risks allow less biased estimation as compared with traditional models.

SUMMARY

Attributable mortality of VAP is about 6%. Accurate diagnostic methods are key to properly estimating it. Traditional statistical models should no longer be used to estimate it. Prevention efforts targeted on patients with intermediate severity may result in the most important outcome benefits.

Alcohol is associated with a lower pneumonia rate after traumatic brain injury

BACKGROUND

Recent evidence supports the beneficial effect of alcohol on patients with traumatic brain injury (TBI). Pneumonia is a known complication following TBI; thus, the purpose of this study was to evaluate the effects of alcohol on pneumonia rates following moderate to severe TBI.

METHODS

From 2005 to 2009, the Los Angeles County Trauma Database was queried for all patients ≥ 14 y of age with isolated moderate to severe TBI and admission serum alcohol levels. The incidence of pneumonia was compared between TBI patients with and without a positive blood alcohol concentration (BAC) level. The study population was then stratified into four BAC levels: None (0 mg/dL), low (0-100 mg/dL), moderate (100-230 mg/dL), and high (≥ 230 mg/dL). Pneumonia rates were compared across these levels.

RESULTS

A total of 3547 patients with isolated, moderate to severe TBI were evaluated. Nearly 66% tested positive for alcohol. The pneumonia rate was significantly lower in the TBI patients who tested positive for alcohol (2.5%) compared with those who tested negative (4.0%, P = 0.017). The pneumonia rate also decreased across increasing BAC levels (linear trend P = 0.03). After logistic regression analysis, a positive ethanol (ETOH) level was associated with a reduced incidence of pneumonia (AOR = 0.62; 95%CI: 0.41-0.93; P = 0.020).

CONCLUSION

A positive serum alcohol level was associated with a significantly lower pneumonia rate in isolated, moderate to severe TBI patients. This may explain the observed mortality reduction in TBI patients who test positive for alcohol. Additional research is warranted to investigate the potential therapeutic implications of this association.

The impact of COPD on ICU mortality in patients with ventilator-associated pneumonia

OBJECTIVE

To determine the impact of COPD on intensive care unit (ICU) mortality in patients with VAP.

METHODS

This prospective observational study was performed in a mixed ICU during a 3-year period. Eligible patients received mechanical ventilation for >48 h and met criteria for microbiologically confirmed VAP. Risk factors for ICU mortality were determined using univariate and multivariable analyses.

RESULTS

Two hundred and fifteen patients with microbiologically confirmed VAP were included. Most VAP episodes were late-onset (88%), and Pseudomonas aeruginosa was the most frequently isolated bacterium (39% of VAP episodes). ICU mortality was significantly lower in non-COPD patients (n = 150) compared to COPD patients (n = 65) (43.3% vs 60%, p = 0.027, OR [95% CI] = 1.96 [1.8-3.54]). Duration (days) of mechanical ventilation and ICU stay median (IQR) in non-COPD patients were 25 (15-42) and 30 (18-48), whereas in COPD patients were 31 (19-45) and 36 (20-48) (p > 0.05). The differences in duration (days) of mechanical ventilation and ICU stay were significant between non-COPD patients and severe COPD (GOLD stage IV) patients (p = 0.001 and p = 0.02, respectively). Multivariable analysis identified COPD [OR (95% CI) 2.58 (1.337-5)], SAPS II [1.024 (1.006-1.024)] and presence of shock at VAP diagnosis [3.72 (1.88-7.39)] as independent risk factors for ICU mortality.

CONCLUSION

COPD, SAPS II, and shock at VAP diagnosis are independently associated with ICU mortality in patients who present VAP.

Impact of cervical spine management brain injury on functional survival outcomes in comatose, blunt trauma patients with extremity movement and negative cervical spine CT: application of the Monte Carlo simulation

Cervical spine (CS) magnetic resonance imaging (MRI) and collar use may prevent quadriplegia, yet create brain injury. We developed a computer model to assess the effect of CS management strategies on outcomes in comatose, blunt trauma patients with extremity movement and a negative CS CT scan. Strategies include early collar removal (ECR), ECR & MRI, late collar removal (LCR), and LCR & MRI. MRI risks include hypoxia, hypotension, increased intracranial pressure (↑ICP), and ventilator-associated pneumonia (VAP). LCR risks include ↑ICP, VAP, and delirium. Model elements include Quadriplegia and Primary, Secondary, LCR, and MRI Brain Injury. The Monte Carlo simulation determines health outcomes (Functional Survival versus Quadriplegia, Severe Brain Disability, or Dead). Utility values are Functional Survival 0.90, Quadriplegia 0.20, Severe Brain Disability 0.10, and Dead 0.00. Years of life expectancy are Functional Survival 39.5, Quadriplegia 20.0, Severe Brain Disability 20.0, and Dead 0.0. Unstable CS rate 2.5%: Functional Survival/1,000: Unstable Patients: ECR 384, LCR 350, LCR & MRI 332, ECR & MRI 331; High-Risk Patients: ECR 161, LCR 151, LCR & MRI 140, ECR & MRI 153; Stable Patients: ECR 596, LCR 587, LCR & MRI 573, ECR & MRI 595. Quality-Adjusted Life Months for Unstable, High-Risk, and Stable Patients are greater with ECR; Stable Patient ECR and ECR & MRI are similar. Unstable CS rate 0.5%: Functional Survival/1000: Unstable Patients: ECR 394, LCR 352, LCR & MRI 332, ECR & MRI 332; High-Risk Patients: ECR 164, LCR 151, LCR & MRI 140, ECR & MRI 152; Stable Patients: ECR 611, LCR 592, LCR & MRI 576, ECR & MRI 598. Quality-Adjusted Life Months for Unstable, High-Risk, and Stable Patients are greater with ECR. LCR and MRI brain injury results in losses of functional survivorship that exceed those from quadriplegia. Model results suggest that early collar removal without cervical spine MRI is a reasonable, and likely the preferable, cervical spine management strategy for comatose, blunt trauma patients with extremity movement and a negative cervical spine CT scan.

Ventilator-associated pneumonia in trauma patients is associated with lower mortality: results from EU-VAP study

BACKGROUND

Differences in trauma patients developing ventilator-associated pneumonia (VAP) are described regarding etiology and risk factors associated. We aim to describe the differences in outcomes in trauma and nontrauma patients with VAP.

METHODS

A prospective, observational study conducted in 27 intensive care units from nine European countries. We included patients requiring invasive mechanical ventilation for >48 hours who developed VAP. Logistic regression model was used to assess the factors independently associated with mortality in trauma patients with VAP.

RESULTS

A total of 2,436 patients were evaluated; 465 developed VAP and of these 128 (27.5%) were trauma patients. Trauma patients were younger than nontrauma (45.3 ± 19.4 vs. 61.1 ± 16.7, p < 0.0001). Nontrauma had higher simplified acute physiology score II compared with trauma patients (45.5 ± 16.3 vs. 41.1 ± 15.2, p = 0.009). Most prevalent pathogens in trauma patients with early VAP were Enterobacteriaceae spp. (46.9% vs. 27.8%, p = 0.06) followed by methicillin-susceptible Staphylococcus aureus (30.6% vs. 13%, p = 0.03) and then Haemophilus influenzae (14.3% vs. 1.9%, p = 0.02), and the most prevalent pathogen in late VAP was Acinetobacter baumannii (12.2% vs. 44.4%, p < 0.0001). Mortality was higher in nontrauma patients than in trauma patients (42.6% vs. 17.2%, p < 0.001, odds ratio [OR] = 3.55, 95%CI = 2.14-5.88). A logistic regression model adjusted for sex, age, severity of illness at intensive care unit admission, and sepsis-related organ failure assessment score at the day of VAP diagnosis confirmed that trauma was associated with a lower mortality compared with nontrauma patients (odds ratio [OR] = 0.37, 95%CI = 0.21-0.65).

CONCLUSIONS

Trauma patients developing VAP had different demographic characteristics and episodes of etiology. After adjustment for potential confounders, VAP episodes in trauma patients are associated with lower mortality when compared with nontrauma patients.

Ventilator-associated pneumonia and mortality: a systematic review of observational studies

OBJECTIVE

To determine the attributable mortality of ventilator-associated pneumonia in a systematic review and meta-analysis of observational studies. Ventilator-associated pneumonia is generally believed to increase the mortality of patients. This notion is predominantly based on the results of observational studies.

DATA SOURCE

We performed a systematic search strategy using PubMed, Web of Science, and Embase from their inception through February 2007. In addition, a reference and related article search was performed.

STUDY SELECTION

Studies were included if they reported mortality rates of patients with and without ventilator-associated pneumonia.

DATA EXTRACTION AND SYNTHESIS

Fifty-two studies with a total of 17,347 patients met the inclusion criteria. Pooling of all studies resulted in relative risk of 1.27 (95% Confidence Interval = 1.15-1.39), but heterogeneity was considerable (I2 statistic = 69%). The origin of heterogeneity could not be explained by differences in study design, study quality, and diagnostic approach. However, heterogeneity was limited for studies investigating only trauma patients (I2 = 1.3%) or patients with acute respiratory distress syndrome (I2 = 0%), with estimated relative risk of 1.09 (95% Confidence Interval = 0.87-1.37) among trauma patients and 0.86 (95% Confidence Interval = 0.72-1.04) among patients with acute respiratory distress syndrome.

CONCLUSIONS

There is no evidence of attributable mortality due to ventilator-associated pneumonia in patients with trauma or acute respiratory distress syndrome. However, in other nonspecified patient groups, there is evidence for attributable mortality due to ventilator-associated pneumonia, but this could not be quantified due to heterogeneity in study results. More detailed studies, allowing subgroup analyses, are needed to determine the attributable mortality of ventilator-associated pneumonia in these patient populations.

Risks associated with magnetic resonance imaging and cervical collar in comatose, blunt trauma patients with negative comprehensive cervical spine computed tomography and no apparent spinal deficit

INTRODUCTION

In blunt trauma, comatose patients (Glasgow Coma Scale score 3 to 8) with a negative comprehensive cervical spine (CS) computed tomography assessment and no apparent spinal deficit, CS clearance strategies (magnetic resonance imaging [MRI] and prolonged cervical collar use) are controversial.

METHODS

We conducted a literature review to delineate risks for coma, CS instability, prolonged cervical collar use, and CS MRI.

RESULTS

Based on our search of the literature, the numbers of functional survivor patients among those who had sustained blunt trauma were as follows: 350 per 1,000 comatose unstable patients (increased intracranial pressure [ICP], hypotension, hypoxia, or early ventilator-associated pneumonia); 150 per 1,000 comatose high-risk patients (age > 45 years or Glasgow Coma Scale score 3 to 5); and 600 per 1,000 comatose stable patients (not unstable or high risk). Risk probabilities for adverse events among unstable, high-risk, and stable patients were as follows: 2.5% for CS instability; 26.2% for increased intensive care unit complications with prolonged cervical collar use; 9.3% to 14.6% for secondary brain injury with MRI transportation; and 20.6% for aspiration during MRI scanning (supine position). Additional risk probabilities for adverse events among unstable patients were as follows: 35.8% for increased ICP with cervical collar; and 72.1% for increased ICP during MRI scan (supine position).

CONCLUSION

Blunt trauma coma functional survivor (independent living) rates are alarming. When a comprehensive CS computed tomography evaluation is negative and there is no apparent spinal deficit, CS instability is unlikely (2.5%). Secondary brain injury from the cervical collar or MRI is more probable than CS instability and jeopardizes cerebral recovery. Brain injury severity, probability of CS instability, cervical collar risk, and MRI risk assessments are essential when deciding whether CS MRI is appropriate and for determining the timing of cervical collar removal.

Antimicrobial treatment for ventilator-associated tracheobronchitis: a randomized, controlled, multicenter study

Introduction

Ventilator-associated tracheobronchitis (VAT) is associated with increased duration of mechanical ventilation. We hypothesized that, in patients with VAT, antibiotic treatment would be associated with reduced duration of mechanical ventilation.

Methods

We conducted a prospective, randomized, controlled, unblinded, multicenter study. Patients were randomly assigned (1:1) to receive or not receive intravenous antibiotics for 8 days. Patients with ventilator-associated pneumonia (VAP) prior to VAT and those with severe immunosuppression were not eligible. The trial was stopped early because a planned interim analysis found a significant difference in intensive care unit (ICU) mortality.

Results

Fifty-eight patients were randomly assigned. Patient characteristics were similar in the antibiotic (n = 22) and no antibiotic (n = 36) groups. Pseudomonas aeruginosa was identified in 32% of VAT episodes. Although no difference was found in mechanical ventilation duration and length of ICU stay, mechanical ventilation-free days were significantly higher (median [interquartile range], 12 [8 to 24] versus 2 [0 to 6] days, P < 0.001) in the antibiotic group than in the no antibiotic group. In addition, subsequent VAP (13% versus 47%, P = 0.011, odds ratio [OR] 0.17, 95% confidence interval [CI] 0.04 to 0.70) and ICU mortality (18% versus 47%, P = 0.047, OR 0.24, 95% CI 0.07 to 0.88) rates were significantly lower in the antibiotic group than in the no antibiotic group. Similar results were found after exclusion of patients with do-not-resuscitate orders and those randomly assigned to the no antibiotic group but who received antibiotics for infections other than VAT or subsequent VAP.

Conclusion

In patients with VAT, antimicrobial treatment is associated with a greater number of days free of mechanical ventilation and lower rates of VAP and ICU mortality. However, antibiotic treatment has no significant impact on total duration of mechanical ventilation.

Trial registration

ClinicalTrials.gov, number NCT00122057.

Respiratory care

PURPOSE OF THE REVIEW

Neurosurgical patients frequently develop respiratory complications, adversely affecting neurologic outcome and survival. The review summarizes current literature and management of respiratory complications associated with brain injury.

MAJOR FINDINGS

Respiratory complications are commonly associated with traumatic brain injury and subarachnoid haemorrhage. Lung-protective ventilation with reduced tidal volumes improves outcome in acute lung injury, and should be applied to neurosurgical patients in the absence of increased intracranial pressure. Weaning from the mechanical ventilation should be initiated as soon as possible, although the role of neurological status in the weaning process is not clear. Prevention of pneumonia and aspiration improves survival. In patients with difficult weaning, early bedside percutaneous tracheostomy should be considered.

FURTHER INVESTIGATIONS

Further studies are warranted to elucidate an optimal oxygenation and ventilation in brain-injured patients, weaning strategies, predictors of the failed weaning and extubation, respiratory support in patients with difficulties to wean, and early tracheostomy.

Ventilator-associated pneumonia in severe traumatic brain injury

INTRODUCTION

Pneumonia is an important cause of morbidity following severe traumatic brain injury (TBI). However, previous studies have been limited by inclusion of specific patient subgroups or by selection bias. The primary objective of this study was to describe the incidence, risk factors for, and outcome of ventilator-associated pneumonia in an unselected population-based cohort of patients with severe TBI. An additional goal was to define the relationship of ventilator-associated pneumonia (VAP) with nonneurological organ dysfunction.

METHODS

A prospective, observational cohort study was performed at Foothills Medical Centre, the sole adult tertiary-care trauma center servicing southern Alberta. All patients with severe TBI requiring ventilation for more than 48 hours between May 1, 2000 and December 30, 2002 were included.

RESULTS

A total of 60 patients (45%) acquired VAP for an incidence density of 42.7/1000 ventilator days. Patients with polytrauma were at higher risk (risk ratio 1.7, 95% confidence interval, 0.9-3.1) for development of VAP than those with isolated head injury. Development of VAP was associated with a significantly greater degree of nonneurological organ system dysfunction. Although VAP was not associated with increased hospital mortality, patients who developed VAP had a longer duration of mechanical ventilation (15 versus 8 days, p < 0.0001), longer intensive care unit (17 versus 9 days, p < 0.0001) and hospital (60 versus 28 days, p = 0.003) lengths of stay, and more often required tracheostomy (35 versus 18%, p = 0.003).

CONCLUSIONS

VAP occurs frequently and is associated with significant morbidity in patients with severe TBI.

Ventilator-associated pneumonia: breaking the vicious circle of antibiotic overuse

OBJECTIVE

To assess the rate of appropriateness of empirical antimicrobial therapy for ventilator-associated pneumonia, to evaluate de-escalation in patients with ventilator-associated pneumonia treated according to local pathway, and to identify the bacteria responsible for recurrence of ventilator-associated pneumonia.

DESIGN

Prospective observational study during a 36-month period.

SETTING

Medical-surgical intensive care unit of a university hospital.

PATIENTS

One hundred and fifteen patients hospitalized in an intensive care unit developing ventilator-associated pneumonia with positive cultures. The patients with ventilator-associated pneumonia were treated with limited-spectrum antibiotics (i.e., without activity against Pseudomonas aeruginosa) if they had no prior hospitalization (within 21 days) or prior administration of antibiotics (within 10 days). Quantitative cultures obtained by bronchoscopy or tracheal aspiration were used to reassess empirical therapy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A limited-spectrum therapy was used in 79 patients (69%). Empirical antimicrobial therapy was appropriate in 100 patients (85%). The mortality rate was significantly higher in the patients in whom empirical therapy was inappropriate than in those in whom treatment was appropriate (47 vs. 20%, p=.04). De-escalation was done in respectively 26% and 72% of patients with early- and late-onset ventilator-associated pneumonia, whereas treatment was escalated in 27 patients (23%). Ventilator-associated pneumonia episodes were recurrent in 22 cases, including eight episodes due to high-risk bacteria.

CONCLUSIONS

A rational empirical antimicrobial therapy for ventilator-associated pneumonia using limited-spectrum antibiotics is possible if local ecology and patient medical history and clinical status are considered. In addition, de-escalation is feasible in 42% of patients. This integrative approach may reduce the emergence of resistant bacteria, which in turns reduces the need for broad-spectrum antibiotics, breaking the vicious circle of antibiotic overuse.

Impact of ventilator-associated pneumonia in patients with severe head injury

BACKGROUND

The impact of ventilator-associated pneumonia (VAP) on outcome seems to vary depending on the critically ill patients we analyze. Our objective, therefore, has been to evaluate the influence of VAP on the mortality and morbidity in patients with severe head injury (Glasgow Coma Scale score </= 8).

METHODS

A prospective, matched, case-control study was conducted in our intensive care unit (ICU) for a 3-year period (1998-2000). Seventy-two patients with severe head injury (HI) who developed VAP were matched with 72 patients with severe HI without VAP. The matching criteria were as follows: age (+/- 5 years); category of HI based on computed tomographic scanning; Acute Physiology and Chronic Health Evaluation II (+/- 4 points) score; Injury Severity Score (+/- 4 points); and duration of mechanical ventilation. VAP was diagnosed on the basis of quantitative microbiologic criteria.

RESULTS

Mortality did not differ significantly between cases and matched control subjects (15 [20.8%] vs. 11 [15.3%], p = 0.54). However, patients with VAP had a significantly longer duration of mechanical ventilation (median, 14 vs. 10 days; p = 0.015) and ICU stay (median, 21 vs. 15.5 days; p = 0.008). The occurrence of multiple organ failure was also significantly more frequent among the case group (33.3% vs. 12.5%, p = 0.004) during the overall ICU stay.

CONCLUSION

VAP does not seem to be associated with a significantly increased risk of death in patients with severe HI, but it may be associated with greater morbidity during the ICU stay.

[Management of ventilator acquired pneumonia]

Ventilator-associated pneumonia occurs in the evolution of 8 to 70% of patients in the Intensive Care Unit. It is the main site of nosocomial infection for mechanically ventilated patients. Nosocomial pneumonia represents an important cause of morbidity and mortality, despite progresses in antibiotic prescription, use of intensive care and prevention. This review is based on the ATS guidelines, and reviews epidemiology, diagnosis and treatment of ventilator-acquired pneumonia, in non-immunocompromised adults.

Effect of oropharyngeal decontamination by povidone-iodine on ventilator-associated pneumonia in patients with head trauma*

OBJECTIVE

To evaluate the effect of a regular oropharyngeal application of povidone-iodine on the prevalence of ventilator-associated pneumonia in patients with severe head trauma.

DESIGN

Prospective randomized study.

SETTING

A surgical intensive care unit of a university hospital.

INTERVENTIONS

Patients with severe head trauma (Glasgow Coma Score of < or =8) expected to need ventilation for > or =2 days were prospectively randomized into three groups: those receiving nasopharynx and oropharynx rinsing with 20 mL of a 10% povidone-iodine aqueous solution, reconstituted in a 60-mL solution with sterile water (povidone-iodine group); those receiving nasopharynx and oropharynx rinsing with 60 mL of saline solution (saline group); or those undergoing a standard regimen without any instillation but with aspiration of oropharyngeal secretions (control group).

MEASUREMENTS AND MAIN RESULTS

The prevalence of ventilator-associated pneumonia was compared among the three groups. A total of 98 patients were analyzed (povidone-iodine group, n = 36; saline group, n = 31; and control group, n = 31). A total of 28 cases of ventilator-associated pneumonia were diagnosed. There was a significant decrease in the rate of ventilator-associated pneumonia in the povidone-iodine group when compared with the saline and control groups (3 of 36 patients [8%] vs. 12 of 31 patients [39%] and 13 of 31 patients [42%], respectively; p = .003 and .001, respectively). The length of stay and mortality in the surgical intensive care unit were not statistically different between the three groups.

CONCLUSIONS

The regular administration of povidone-iodine may be an effective strategy for decreasing the prevalence of ventilator-associated pneumonia in patients with severe head trauma.

Risk and prognostic factors of ventilator-associated pneumonia in trauma patients

OBJECTIVE

To assess the risk and prognostic factors of ventilator-associated pneumonia in trauma patients, with an emphasis on the inflammatory response.

DESIGN

Case-control study.

SETTING

Trauma intensive care unit.

PATIENTS

Of 190 consecutive mechanically ventilated patients, those with microbiologically confirmed pneumonia (n = 62) were matched with 62 controls without pneumonia.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Clinical, microbiological, and outcome variables were recorded. Cytokines were measured in serum and blind bronchoalveolar lavage specimens at onset of pneumonia. Multivariate analyses of risk and prognostic factors for ventilator-associated pneumonia were done. Increased severity of head and neck injury (odds ratio, 11.9; p < .001) was the only independent predictor of pneumonia. Among patients with pneumonia, serum levels of interleukin-6 (p = .019) and interleukin-8 (p = .036) at onset of pneumonia were higher in nonresponders to treatment. Moreover, serum levels of tumor necrosis factor-alpha (p = .028) and interleukin-6 (p = .007) at onset of pneumonia were higher in nonsurvivors. Mortality in the intensive care unit was 23% in cases and controls. Nonresponse to antimicrobial treatment (odds ratio, 22.2; p = .001) and the use of hyperventilation (p = .021) were independent predictors of mortality in the intensive care unit for patients with pneumonia.

CONCLUSIONS

Severe head and neck trauma is strongly associated with ventilator-associated pneumonia. A higher inflammatory response is associated with nonresponse to treatment and mortality among patients with pneumonia. Although pneumonia did not influence mortality, nonresponse to treatment independently predicted mortality among these patients.

Impact of ventilator-associated pneumonia on outcome in patients with COPD

PURPOSES

The aim of this study was to determine the impact of ventilator-associated pneumonia (VAP) on outcome in patients with COPD.

METHODS

Prospective, observational, case-control study conducted in a 30-bed ICU during a 5-year period. All COPD patients who required intubation and mechanical ventilation (MV) for > 48 h were eligible. VAP diagnosis was based on clinical, radiographic, and quantitative microbiologic criteria. Patients with unconfirmed VAP were excluded, as well as patients with ventilator-associated tracheobronchitis without subsequent VAP. Matching (1:1) criteria included MV duration before VAP occurrence, age +/- 5 years, simplified acute physiology score II on ICU admission +/- 5, and ICU admission category. Variables associated with ICU mortality were determined using univariate and multivariate analyses.

RESULTS

A total of 1,241 patients were eligible; 181 patients (14%) were excluded, including 133 patients for VAT and 48 patients for unconfirmed VAP. VAP developed in 77 patients (6%), and all were successfully matched. Pseudomonas aeruginosa was the most frequently isolated bacteria (31%). ICU mortality rate (64% vs 28%), duration of MV (24 +/- 15 d vs 13 +/- 11 d [+/- SD]), and ICU stay (26 +/- 17 d vs 15 +/- 13 d) were significantly (< 0.001) higher in case patients than in control patients. VAP was the only variable independently associated with ICU mortality (odds ratio [OR], 7.7; 95% confidence interval [CI], 3.2 to 18.6; p < 0.001). In VAP patients who received corticosteroids during their ICU stay compared with those who did not receive corticosteroids, mortality rate (50% vs 82%; OR, 1.8; 95% CI, 1.2 to 2.7; p = 0.002), duration of MV (21 +/- 14 d vs 27 +/- 16 d, p = 0.043), and ICU stay (22 +/- 16 d vs 31 +/- 18 d, p = 0.006) were significantly lower.

CONCLUSION

VAP is associated with increased mortality rates and longer duration of MV and ICU stay in COPD patients.

An integrated approach to prevent and treat respiratory failure in brain-injured patients

PURPOSE OF REVIEW

Brain-injured patients are at increased risk of extracerebral organ dysfunction, in particular ventilator-associated pneumonia. The purpose of this review is to discuss functional abnormalities, clinical treatment, and possible prevention of respiratory function abnormalities in brain-injured patients.

RECENT FINDINGS

Ventilator-associated pneumonia worsens the neurologic outcome and increases the intensive care unit and hospital stay, costs, and risk of death. The respiratory dysfunction can be due to several causes, but atelectasis and/or consolidation of the lower lobes predominates in the most severe cases. Strategies should be implemented to prevent lung infections and accelerate weaning from mechanical ventilation to reduce the incidence of respiratory dysfunction and ventilator-associated pneumonia.

SUMMARY

An integrated approach including appropriate ventilatory, antibiotic, and fluid management could be extremely useful, not only to prevent and more rapidly treat respiratory failure but also to improve neurologic outcome and reduce hospital stay. Further studies are warranted to better elucidate the pathophysiology and clinical treatment of respiratory dysfunction in brain-injured patients.

[Selective digestive decontamination: the light as changed from red to green]

OBJECTIVES

To study the efficacy of selective digestive decontamination (SDD) for the prevention of nosocomial infections, particularly pneumonia, as well as its impact on the emergence of multiresistant bacteria.

DATA SOURCES

Data collected from the Pubmed: original articles, review articles and editorial published on SDD. The keywords were: selective digestive decontamination, pneumonia, intensive care unit, infection.

DATA SELECTION

Ten randomized clinical trials performed since 1995 in mechanically ventilated adult patients hospitalized in intensive care unit.

RESULTS

The rationale for the use of SDD consists on the parenteral administration of a short course of antibiotic associated with the topical use of non-absorbable antibiotics directed against Gram negative bacteria. Five randomized studies described a reduction in the incidence of pneumonia associated with SDD. Only one study has showed a decrease in mortality rate. The other five studies, which present some methodological limitations, concluded the lack of efficacy of SDD. Regarding the emergence of multiresistant bacteria, the literature underlines the role of environment. The use of SDD seems to trigger the resistance in endemic areas, while these are softened in the units with a good control of their ecology.

CONCLUSION

The data from the literature provide arguments to use SDD in targeted patient populations like multiple traumas in intensive care units, which have a low rate of multiresistant bacteria.

Non-neurologic organ dysfunction in severe traumatic brain injury

OBJECTIVE

To describe the incidence of non-neurologic organ dysfunction and its association with outcome in patients with severe traumatic brain injury admitted to intensive care.

DESIGN

Observational cohort study.

SETTING

Foothills Medical Centre, which is the only neurosurgical service in southern Alberta (population approximately 1.3 million).

PATIENTS

Patients were 209 consecutive patients with severe traumatic brain injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Non-neurologic organ dysfunction was measured by the maximum modified multiple organ dysfunction score. Organ system failure was defined as a component score of >/=3 on any day during the patient's intensive care unit stay. One hundred and eighty-five patients (89%) developed dysfunction of at least one non-neurologic organ system. Ninety-six organ system failures were identified in 74 patients (35%). Respiratory failure was the most common non-neurologic organ system failure, occurring in 23% of patients, whereas cardiovascular failure occurred in 18%. Eight patients (4%) had failure of the coagulation system. One patient had renal failure, whereas no patient developed hepatic failure. In a multivariate model, non-neurologic organ dysfunction was independently associated with hospital mortality (odds ratio for hospital mortality, 1.63; 95% confidence interval, 1.34, 1.98 for one maximum modified multiple organ dysfunction score point). Non-neurologic organ dysfunction was also independently associated with dichotomized Glasgow Outcome Score, as a measure of neurologic outcome (odds ratio for unfavorable neurologic outcome, 1.53; 95% confidence interval, 1.22, 1.98 for one maximum modified multiple organ dysfunction score point). The timing of the organ dysfunction did not appear to be important in the prediction of outcome.

CONCLUSIONS

Non-neurologic organ dysfunction is common in patients with severe traumatic brain injury and is independently associated with worse outcome.

First-generation fluoroquinolone use and subsequent emergence of multiple drug-resistant bacteria in the intensive care unit

OBJECTIVE

The objective of this study was to determine the relationship between fluoroquinolone (FQ) use and subsequent emergence of multiple drug-resistant bacteria (MRB) in the intensive care unit (ICU).

DESIGN

The authors conducted a prospective observational cohort study and a case control study.

SETTING

The study was conducted in a 30-bed ICU.

METHODS

All immunocompetent patients hospitalized for >48 hrs who did not receive antibiotics before ICU admission were eligible during a 15-month period. Routine MRB screening was performed at ICU admission and weekly thereafter. This screening included tracheal aspirate and nasal, anal, and axilla swabs. Univariate and multivariate analyses were used to determine risk factors for MRB emergence in the ICU. In addition, a case control study was performed to determine whether FQ use is associated with subsequent emergence of MRB.

RESULTS

Two hundred thirty-nine patients were included; 108 ICU-acquired MRB were isolated in 77 patients. FQ use and longer duration of antibiotic treatment were identified as independent risk factors for MRB occurrence (odds ratio [95% confidence interval [CI] = 3.3 [1.7-6.5], 1.1 [1.0-1.2]; p < .001; respectively). One hundred thirty-five (56%) patients received FQ; matching was successful for 72 (53%) of them. Number of MRB (40 vs. 15 per 1,000 ICU days; p = .019) and percentage of patients with MRB (40% vs. 22%; OR [95% CI] = 1.5 [1.0-2.4]; p = .028) were significantly higher in cases than in controls. Although methicillin-resistant Staphylococcus aureus (26% vs. 12%; OR [95% CI] = 1.6 [.6-2.9]; p = .028) and extending-spectrum beta-lactamase-producing Gram-negative bacilli (11% vs. 1%; OR [95% CI] = 4.7 [0.7-30.2]; p = .017) rates were higher in cases than in controls, ceftazidime or imipenem-resistant Pseudomonas aeruginosa (15% vs. 8%), Acinetobacter baumannii (1% vs. 5%), and Stenotrophomonas maltophilia (2% vs. 1%) rates were similar (p > .05) in case and control patients.

CONCLUSION

FQ use and longer duration of antibiotic treatment are independently associated with MRB emergence. Reducing antimicrobial treatment duration and restricting FQ use could be suggested to control MRB spread in the ICU.

Role of anaerobic bacteria in infections following tracheostomy, intubation, or the use of ventilatory tubes in children

Colonization of the tracheobronchial tree with microorganisms almost always follows tracheal intubation, tracheostomy, or the use of ventilatory tubes. Infection of the tracheostomy wound site frequently occurs after prolonged use of the tracheostomy. The long-term-ventilated child is at high risk for developing tracheobronchitis or nosocomial pneumonia, generally involving aerobic gram-negative or gram-positive bacteria. Several studies have illustrated the role of anaerobic bacteria in lower respiratory tract and tracheostomy wound site infection in intubated children. The predominant anaerobic bacteria were Peptostreptococcus spp and pigmented Prevotella and Porphyromonas spp. Most of these infections are due to polymicrobial aerobic-anaerobic bacterial flora. Appropriate management of mixed pulmonary aerobic and anaerobic infections requires the administration of antimicrobials that are effective against both the aerobic and anaerobic components of the infection.

Risk factors for late-onset ventilator-associated pneumonia in trauma patients receiving selective digestive decontamination

OBJECTIVE

To determine the independent risk factors for late-onset ventilator-associated pneumonia (VAP) in trauma patients receiving selective digestive decontamination (SDD).

DESIGN

A 4-year, prospective cohort study of trauma patients meeting the following criteria: injury severity score >15, and duration of mechanical ventilation >5 days. Predictors of late-onset VAP occurrence were assessed by logistic regression analysis.

POPULATION

All patients received SDD consisting of polymixin E, gentamicin, and amphotericin B applied in nostrils, mouth, and gut with a 3-day course of parenteral cefazolin. VAP was suspected on clinical and radiological signs, and confirmed by the presence of at least one microorganism at a concentration of at least 10(4) CFU/ml on the broncho-alveolar lavage.

MEASUREMENT

Independent risk factors for late-onset VAP.

RESULTS

A late-onset VAP was diagnosed in 90 (56%) out of 159 patients. Predicting factors for late-onset VAP were: use of non-depolarizing muscle relaxant agents for intubation [3.4 (CI 1.08-10.73)], duration of intubation [1.06 (CI 1.01-1.17)], length of intensive care unit (ICU) stay [1.05 (CI 1.02-1.09)], and prior tracheal colonization [1.03 (CI 1.02-1.21)]. Exposure to prior antimicrobial treatment, except SDD, conferred protection [0.3 (0.12-0.74)].

CONCLUSION

This study confirms the role of duration of intubation, length of ICU stay, and prior tracheal colonization in the development of late-onset VAP. The results also highlight the importance of the initial management on the development of late-onset VAP. The type of neuromuscular blocking agents to intubate trauma patients should be evaluated in future studies.

Pulmonary Contusion in Severe Head Trauma Patients

STUDY OBJECTIVE

To evaluate the impact on morbidity and mortality of pulmonary contusion in multiple-trauma patients with severe head trauma.

DESIGN

Matched-paired, case-control study

SETTING

ICU at a tertiary university hospital.

PATIENTS

During a 3-year period, 313 consecutive multiple-trauma patients with severe head trauma (Glasgow coma scale [GCS], </= 8) who were admitted to the ICU.

INTERVENTIONS

Case-control matching criteria were as follows: (1) age difference within 5 years; (2) sex; (3) GCS in two categories; (4) similar pattern of injury; and (5) simplified acute physiology score II in five categories. A pulmonary contusion, defined by the clinical context and the result of a chest CT scan, was diagnosed in 90 patients. Analysis was performed on 90 pairs who were matched with 100% success.

RESULTS

Ninety patients (29%) presented a diagnosis of pulmonary contusion. The presence of pulmonary contusion had an impact on the PaO(2)/fraction of inspired oxygen (FIO(2)) ratio, which was significantly reduced in patients with a pulmonary contusion. The ICU stay, the occurrence of complications such as nosocomial pneumonia or ARDS, the Glasgow outcome scale, and the mortality rate did not significantly differ between case patients and control subjects. Mortality also was not affected when patients were stratified according to the severity of the PaO(2)/FIO(2) ratio.

CONCLUSION

In the study patients, pulmonary contusion alters gas exchange but does not appear to increase the morbidity and mortality of multiple-trauma patients with head trauma. A sample-size effect may limit the interpretation of the study.