A formula for prediction of posttraumatic pneumonia based on early anatomic and physiologic parameters

A recalibrated prediction model can identify level-1 trauma patients at risk of nosocomial pneumonia

INTRODUCTION

Nosocomial pneumonia has poor prognosis in hospitalized trauma patients. Croce et al. published a model to predict post-traumatic ventilator-associated pneumonia, which achieved high discrimination and reasonable sensitivity. We aimed to externally validate Croce's model to predict nosocomial pneumonia in patients admitted to a Dutch level-1 trauma center.

MATERIALS AND METHODS

This retrospective study included all trauma patients (≥ 16y) admitted for > 24 h to our level-1 trauma center in 2017. Exclusion criteria were pneumonia or antibiotic treatment upon hospital admission, treatment elsewhere > 24 h, or death < 48 h. Croce's model used eight clinical variables-on trauma severity and treatment, available in the emergency department-to predict nosocomial pneumonia risk. The model's predictive performance was assessed through discrimination and calibration before and after re-estimating the model's coefficients. In sensitivity analysis, the model was updated using Ridge regression.

RESULTS

809 Patients were included (median age 51y, 67% male, 97% blunt trauma), of whom 86 (11%) developed nosocomial pneumonia. Pneumonia patients were older, more severely injured, and underwent more emergent interventions. Croce's model showed good discrimination (AUC 0.83, 95% CI 0.79-0.87), yet predicted probabilities were too low (mean predicted risk 6.4%), and calibration was suboptimal (calibration slope 0.63). After full model recalibration, discrimination (AUC 0.84, 95% CI 0.80-0.88) and calibration improved. Adding age to the model increased the AUC to 0.87 (95% CI 0.84-0.91). Prediction parameters were similar after the models were updated using Ridge regression.

CONCLUSION

The externally validated and intercept-recalibrated models show good discrimination and have the potential to predict nosocomial pneumonia. At this time, clinicians could apply these models to identify high-risk patients, increase patient monitoring, and initiate preventative measures. Recalibration of Croce's model improved the predictive performance (discrimination and calibration). The recalibrated model provides a further basis for nosocomial pneumonia prediction in level-1 trauma patients. Several models are accessible via an online tool.

LEVEL OF EVIDENCE

Level III, Prognostic/Epidemiological Study.

Trends in the presentation and management of traumatic spinal cord lesions above T6: 20-Year experience in a tertiary-level hospital in Spain

OBJECTIVE

To analyze the changes in demographic and lesion characteristics of persons with acute traumatic spinal cord injury (ATSCI) above T6 over a period of 20 years, and to evaluate their impact on ICU resources use, length of stay and mortality.

DESIGN

Retrospective observational study.

SETTING

Intensive Care Unit (ICU) of the University Hospital Complex of A Coruña, Spain.

PARTICIPANTS

The study included 241 persons between 1998 and 2017 with an ATSCI above T6. For the purposes of the analysis, the overall study period was divided into three subperiods.

RESULTS

Both the mean age of the people with ATSCI (49 vs. 51 vs. 57 years; P = 0.046) and the Charlson Comorbidity Index were higher during the last subperiod (mean: 1.9 ± 2.2; P &lt; 0.01). The most frequent cause of the injury was falls, whose percentage increased over the years. The most common classification in the American Spinal Injury Association Impairment scale was grade A. An increase in the score of the Acute Physiology and Chronic Health Evaluation (APACHE II) score was observed (median: 9 vs. 10 vs. 15; P &lt; 0.01). The length of stay in the ICU has decreased significantly over the years (30 ± 19 vs. 22 ± 14 vs. 19 ± 13 days). No significant differences were found between the rates of ICU or in-hospital mortality recorded over the three subperiods.

CONCLUSIONS

Despite the progressive increase in the age, comorbidity, and APACHE II, the length of ICU stay decreased significantly, with no associated changes in the mortality rates.

Ventilator Associated Pneumonia and Intubation Location in Adults with Traumatic Injuries: Systematic Review and Meta-analysis

BACKGROUND

Ventilator associated pneumonia (VAP) is an important cause of morbidity and mortality among critically ill patients, particularly those who present with traumatic injuries. This review aims to determine whether patients with traumatic injuries who are intubated in the prehospital setting are at higher risk of developing VAP compared to those intubated in the hospital.

METHODS

A systematic review of Medline, Scopus and Cochrane electronic databases was conducted from inception through January 2021. Inclusion criteria were patients with traumatic injuries who were intubated in the prehospital or hospital settings with VAP as an outcome. Using a random effects model, the risk of VAP across study arms was compared by calculating a summary relative risk (RR) with 95% confidence intervals (CI). The results of individual studies were also summarized qualitatively.

RESULTS

The search identified 754 articles of which 6 studies (N = 2990) met inclusion criteria. All studies were good quality based on assessment with the Newcastle Ottawa scale. Prehospital intubation demonstrated an increased risk of VAP development in 2 of the 6 studies. Among the 6 studies, the overall quality weighted risk ratio was 1.09 (95% CI 0.90-1.31).

CONCLUSIONS

Traumatically injured patients who are intubated in the prehospital setting have a similar risk of developing VAP compared to those that are intubated in the hospital setting.

LEVEL OF EVIDENCE

Level IV systematic review and meta-analysis.

Sarcopenia is an effective predictor of difficult-to-wean and mortality among critically ill surgical patients

BACKGROUND

Critically-ill surgical patients are at higher risk for sarcopenia, which is associated with worse survival. Sarcopenia may impair the respiratory musculature, which can subsequently influence the outcome of ventilator weaning. Although there are a variety of weaning parameters predictive of weaning outcomes, none have tried to incorporate "muscle strength" or "sarcopenia". The aim of the current study was to explore the association between sarcopenia and difficult-to-wean (DtW) in critically-ill surgical patients. The influence of sarcopenia on ICU mortality was also analyzed.

METHODS

Ninety-six patients undergoing mechanical ventilation in the surgical intensive care unit (ICU) were enrolled. Demographic data and weaning parameters were recorded from the prospectively collected database, and the total psoas muscle area (TPA) was determined at the level of the 3rd lumbar vertebra by computed tomography. Sarcopenia was defined by previously established cut-off points and its influence on clinical outcomes was examined. Receiver operating characteristic (ROC) curve analysis was conducted to investigate the predictive capability of TPA and weaning parameters for predicting weaning outcomes.

RESULTS

The median age of the studied patients was 73 years. Thirty patients (31.3%) were sarcopenic and 30 (31.3%) were defined as DtW. Eighteen patients (18.8%) had ICU mortality. Multivariate logistic regression analyses revealed that sarcopenia was an independent risk factor for DtW and ICU mortality. The area under the ROC curve (AUC) of TPA for predicting successful weaning was 0.727 and 0.720 in female and male patients, respectively. After combining TPA and conventional weaning parameters, the AUC for DtW increased from 0.836 to 0.911 and from 0.835 to 0.922 in female and male patients, respectively.

CONCLUSION

Sarcopenia is an independent risk factor for DtW and ICU mortality. TPA has predictive value when assessing weaning outcomes and can be used as an effective adjunct predictor along with conventional weaning parameters.

Risk factors for ventilator-associated pneumonia in trauma patients: A descriptive analysis

BACKGROUND

We sought to evaluate the risk factors for developing ventilator-associated pneumonia (VAP) and whether the location of intubation posed a risk in trauma patients.

METHODS

Data were retrospectively reviewed for adult trauma patients requiring intubation for > 48 hours, admitted between 2010 and 2013. Patients' demographics, clinical presentations and outcomes were compared according to intubation location (prehospital intubation [PHI] vs. trauma room [TRI]) and presence vs. absence of VAP. Multivariate regression analysis was performed to identify predictors of VAP.

RESULTS

Of 471 intubated patients, 332 patients met the inclusion criteria (124 had PHI and 208 had TRI) with a mean age of 30.7±14.8 years. PHI group had lower GCS (P=0.001), respiratory rate (P=0.001), and higher frequency of head (P=0.02) and chest injuries (P=0.04). The rate of VAP in PHI group was comparable to the TRI group (P=0.60). Patients who developed VAP were 6 years older, had significantly lower GCS and higher ISS, head AIS, and higher rates of polytrauma. The overall mortality was 7.5%, and was not associated with intubation location or pneumonia rates. In the early-VAP group, gram-positive pathogens were more common, while gram-negative microorganisms were more frequently encountered in the late VAP group. Logistic regression analysis and modeling showed that the impact of the location of intubation in predicting the risk of VAP appeared only when chest injury was included in the models.

CONCLUSION

In trauma, the risk of developing VAP is multifactorial. However, the location of intubation and presence of chest injury could play an important role.

Trauma patients meeting both Centers for Disease Control and Prevention's definitions for ventilator-associated pneumonia had worse outcomes than those meeting only one

BACKGROUND

The Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN) replaced its old definition for ventilator-associated pneumonia (VAP) with the ventilator-associated events algorithm in 2013. We sought to compare the outcome of trauma patients meeting the definitions for VAP in the two modules.

METHODS

Trauma patients with blunt or penetrating injuries and with at least 2 d of ventilator support were identified from the trauma registry from 2013 to 2014. VAP was determined using two methods: (1) VAP as defined by the "old," clinically based NHSN definition and (2) possible VAP as defined by the updated "new" NHSN definition. Cohen's kappa statistic was determined to compare the two definitions for VAP. To compare demographic and clinical outcomes, the chi-square and Student's t-tests were used for categorical and continuous variables, respectively.

RESULTS

From 2013 to 2014, there were 1165 trauma patients admitted who had at least 2 d of ventilator support. Seventy-eight patients (6.6%) met the "new" NHSN definition for possible VAP, 361 patients (30.9%) met the "old" definition of VAP, and 68 patients (5.8%) met both definitions. The kappa statistic between VAP as defined by the "new" and "old" definitions was 0.22 (95% confidence interval, 0.17-0.27). There were no differences in age, gender, race, or injury severity score when comparing patients who met the different definitions. Those satisfying both definitions had longer ventilator support days (P = 0.0009), intensive care unit length of stay (LOS; P = 0.0003), and hospital LOS (P = 0.0344) when compared with those meeting only one definition. There was no difference in mortality for those meeting both and those meeting the old definition for VAP; patients meeting both definitions had higher respiratory rate at arrival (P = 0.0178).

CONCLUSIONS

There was no difference in mortality between patients meeting the "old" and "new" NHSN definitions for VAP; those who met "both" definitions had longer ventilator support days, intensive care unit, and hospital LOS.

Ventilator-Associated Pneumonia: A Review

Ventilator-associated pneumonia is the most frequent intensive care unit (ICU)-related infection in patients requiring mechanical ventilation. In contrast to other ICU-related infections, which have a low mortality rate, the mortality rate for ventilator-associated pneumonia ranges from 20% to 50%. These clinically significant infections prolong duration of mechanical ventilation and ICU length of stay, underscoring the financial burden these infections impose on the health care system. The causes of ventilator-associated pneumonia are varied and differ across different patient populations and different types of ICUs. This varied presentation underscores the need for the intensivist treating the patient with ventilator-associated pneumonia to have a clear knowledge of the ambient microbiologic flora in their ICU. Prevention of this disease process is of paramount importance and requires a multifaceted approach. Once a diagnosis of ventilator-associated pneumonia is suspected, early broad-spectrum antibiotic administration decreases morbidity and mortality and should be based on knowledge of the sensitivities of common infecting organisms in the ICU. De-escalation of therapy, once final culture results are available, is necessary to minimize development of resistant pathogens. Duration of therapy should be based on the patient’s clinical response, and every effort should be made to minimize duration of therapy, thus further minimizing the risk of resistance.

Witnessed aspiration in trauma: Frequent occurrence, rare morbidity--A prospective analysis

BACKGROUND

Aspiration events (AEs) are a well-recognized complication in trauma patients and have traditionally been considered a risk factor for pneumonia. Despite this, there is no consensus on the incidence or clinical significance of AE in the trauma population.

METHODS

All patients admitted as trauma team activations at our Level I trauma center who were intubated in the field or on arrival from September 2013 to August 2014 were prospectively collected. Field and admission data including witnessed AEs were analyzed. Additional hospital data included imaging, associated injuries, laboratory, and clinical data. Early respiratory failure, pneumonia, and hospital mortality were collected.

RESULTS

During the study period, 228 patients met inclusion criteria. Median age was 35.5 years, and Injury Severity Score (ISS) was 21.0. Overall, 58 patients (25.4%) had witnessed AEs. Patients with AE had significantly higher ISS (26.0 vs. 17.0, p = 0.027) and lower Glasgow Coma Scale (GCS) score on admission (median, 4.0 vs. 7.0; p = 0.003), despite similar field GCS score (p = 0.946). Body mass index (median, 27.2 vs. 26.2; p = 0.374) and intoxication rates (86.2% vs. 83.5%, p = 0.835) were similar between groups. Early pneumonia and respiratory failure were rare in all patients and were not higher in those with AE. Although mortality was higher after AE in patients who died directly after admission (51.7% vs. 30.0%, p = 0.004), in patients who survived to intensive care unit admission, there was no longer a difference between groups and aspiration was not an independent predictor of mortality (p = 0.107) on multivariable regression analysis.

CONCLUSION

The rate of aspiration in trauma is high and more likely to occur in patients with increased injury burden or depressed GCS score. In patients who survive past admission, early pneumonia rates are similar, regardless of AE. These data suggest that aspiration is a marker of severe illness and is associated with but not an independent predictor of mortality.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

A pilot study of the noninvasive assessment of the lung microbiota as a potential tool for the early diagnosis of ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) remains a common complication in critically ill surgical patients, and its diagnosis remains problematic. Exhaled breath contains aerosolized droplets that reflect the lung microbiota. We hypothesized that exhaled breath condensate fluid (EBCF) in hygroscopic condenser humidifier/heat and moisture exchanger (HCH/HME) filters would contain bacterial DNA that qualitatively and quantitatively correlate with pathogens isolated from quantitative BAL samples obtained for clinical suspicion of pneumonia.

METHODS

Forty-eight adult patients who were mechanically ventilated and undergoing quantitative BAL (n = 51) for suspected pneumonia in the surgical ICU were enrolled. Per protocol, patients fulfilling VAP clinical criteria undergo quantitative BAL bacterial culture. Immediately prior to BAL, time-matched HCH/HME filters were collected for study of EBCF by real-time polymerase chain reaction. Additionally, convenience samples of serially collected filters in patients with BAL-diagnosed VAP were analyzed.

RESULTS

Forty-nine of 51 time-matched EBCF/BAL fluid samples were fully concordant (concordance > 95% by κ statistic) relative to identified pathogens and strongly correlated with clinical cultures. Regression analysis of quantitative bacterial DNA in paired samples revealed a statistically significant positive correlation (r = 0.85). In a convenience sample, qualitative and quantitative polymerase chain reaction analysis of serial HCH/HME samples for bacterial DNA demonstrated an increase in load that preceded the suspicion of pneumonia.

CONCLUSIONS

Bacterial DNA within EBCF demonstrates a high correlation with BAL fluid and clinical cultures. Bacterial DNA within EBCF increases prior to the suspicion of pneumonia. Further study of this novel approach may allow development of a noninvasive tool for the early diagnosis of VAP.

There's no place like home: boarding surgical ICU patients in other ICUs and the effect of distances from the home unit

BACKGROUND

Intensive care units (ICUs) function frequently at capacity, requiring incoming critically ill patients to be placed in alternate geographically distinct ICUs. In some medical ICU populations, "boarding" in an overflow ICU has been associated with increased mortality. We hypothesized that surgical ICU patients experience more complications when boarding in an overflow ICU and that the frequency of these complications are greatest in boarders farthest from the home unit (HU).

METHODS

A 5-year (June 2005 to June 2010) retrospective review of a prospectively maintained ICU database was performed, and demographics, severity of illness, length of stay, and incidence of ICU complications were extracted. Distances between boarding patients' rooms and the HU were measured. Complications occurring in patients located in the same floor (BUSF) and different floor (BUDF) boarding units were compared and stratified by distance from HU to the patient room. Logistic regression was used to develop control for known confounders.

RESULTS

A total of 7,793 patients were admitted to the HU and 833 to a boarding unit (BUSF, n = 712; BUDF, n = 121). Boarders were younger, had a lower length of stay, and Acute Physiology and Chronic Health Evaluation II and were more often trauma/emergency surgery patients. Compared with in-HU patients, the incidence of aspiration pneumonia (2.2% vs. 3.6%, p < 0.01) was greater in BUSF patients and highest in those farthest from the HU (odds ratio [OR], 2.39; p = 0.01). Delirium occurred less often in HU than in BUDF patients (3.3% vs. 8.3 %, p < 0.01), and both delirium (OR, 6.09, p < 0.01) and ventilator-associated pneumonia (OR, 4.49, p < 0.05) were more frequent in patients farther from the HU.

CONCLUSION

Certain ICU complications occur more frequently in boarding patients particularly if they are located on a different floor or far from the HU. When surgical ICU bed availability forces overflow admissions to non-home ICUs, greater interdisciplinary awareness, education, and training may be needed to ensure equivalent care and outcomes.

LEVEL OF EVIDENCE

Epidemiologic study, level III. Therapeutic study, level IV.

Incidence, prevalence, and occurrence rate of infection among adults hospitalized after traumatic brain injury: study protocol for a systematic review and meta-analysis

BACKGROUND

Infection occurs commonly among patients hospitalized after traumatic brain injury (TBI) and has been associated with increased intensive care unit and hospital lengths of stay and an elevated risk of poor neurological outcome and mortality. However, as many relevant published studies to date have varied in the type and severity of TBI among included patients as well as in their design (randomized versus non-randomized), risk of bias, and setting (hospital ward versus intensive care unit), their reported estimates of infection occurrence vary considerably. Thus, the purpose of this systematic review and meta-analysis is to estimate the incidence, prevalence, and occurrence rate of infection among patients hospitalized after TBI.

METHODS/DESIGN

We will search electronic bibliographic databases (MEDLINE, EMBASE, PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, Web of Science, the Cochrane Central Register of Controlled Trials (CENTRAL), and the Cochrane Database of Systematic Reviews) from their first available date as well as personal files, reference lists of included articles, and conference proceedings. Two investigators will independently screen titles and abstracts and select cohort studies, cross-sectional studies, and randomized controlled trials involving adults hospitalized after TBI that reported estimates of cumulative incidence, incidence rate, prevalence, or occurrence rate of infection for inclusion in the systematic review. These investigators will also independently extract data and assess risk of bias. We will exclude studies with fewer than ten patients; experimental groups allocated to treatment with antibiotics, glucocorticoids, immunosuppressants, barbiturates, or hypothermia; and studies focused on military/combat-related TBI. Pooled estimates of cumulative incidence, incidence rate, prevalence, and occurrence rate will be calculated using random effects models. We will also calculate I2 and Cochran Q statistics to assess for inter-study heterogeneity and conduct stratified analyses and univariate meta-regression to determine the influence of pre-defined study-level covariates on our pooled estimates.

DISCUSSION

This study will compile the world literature regarding the epidemiology of infection among adults hospitalized after TBI. A better understanding of the role of infection will be helpful in the development of guidelines for patient management. This protocol has been registered in the PROSPERO International Prospective Register of Systematic Reviews (ID: CRD42013005146).

Should Uncooperative Trauma Patients with Suspected Head Injury be Intubated?

In trauma patients with a suspicion for traumatic brain injury (TBI), a head computed tomography (CT) scan is imperative. However, uncooperative patients often cannot undergo imaging without sedation and may need to be intubated. Our hypothesis was that among mildly injured trauma patients, in whom there is a suspicion of a head injury, uncooperative patients have higher rates of TBI and intubation should be considered to obtain a CT scan. We found that uncooperative patients intubated for diagnostic purposes were more likely to have moderate to severe TBI than nonintubated patients (21.4 vs 8.4%, P < 0.0001) and uncooperative behavior leading to intubation was an independent predictor of TBI (odds ratio, 2.5; 95% confidence interval, 1.5 to 4.5). Of patients with brain injury, intubated patients more often had a head Abbreviated Injury Scale score of 4 (20.8 vs 7.9%, P = 0.04). Uncooperative intubated patients had longer hospital stays (3.6 vs 2.6 days, P = 0.003) and higher mortality (0.9 vs 0.2%, P = 0.02) than nonintubated patients. Uncooperative behavior may be an early warning sign of TBI and the trauma surgeon should consider intubating uncooperative trauma patients if there is suspicion for brain injury based on the mechanism of their trauma.

Pre-hospital intubation factors and pneumonia in trauma patients

BACKGROUND

We reported similar rates of ventilator-associated pneumonia (VAP) previously in trauma patients intubated either in a pre-hospital (PH) venue or the emergency department. A subset of PH intubations with continuous quality assessment was re-examined to identify the intubation factors associated with VAP.

METHODS

The subgroup was derived from an existing data set of consecutive adult trauma patients intubated prior to Level I trauma center admission July 2007-July 2008. Intubation details recorded included bag-valve mask ventilation (BVM) and the presence of material in the airway. The diagnosis of VAP was made preferentially by quantitative bronchoalveolar lavage (BAL) cultures (≥ 10⁴ colony-forming units indicating infection). Baseline data, injury characteristics, and circumstances of intubation of patients with and without VAP were compared by univariable analysis.

RESULTS

Detailed data were available for 197 patients; 32 (16.2%) developed VAP, on average 6.0±0.7 days after admission. Baseline characteristics were similar in the groups, but diabetes mellitus was more common in the VAP group (4 [12.5%] vs. 5 [3.0%]; p=0.02). There was a higher rate of blunt injury in the VAP patients (28 [87.5%] vs. 106 [64.2%]; p=0.01) and higher injury severity scores (33.1±2.8 vs. 23.0±1.0; p=0.0002) and chest Abbreviated Injury Scores (2.6±0.3 vs. 1.5±0.1; p=0.002). Lower Glasgow Coma Scale scores (7.9±0.9 vs. 9.9±0.4; p=0.04) and greater use of BVM (18 [56.3%] vs. 56 [34.0%]; p=0.02) were observed in patients who developed VAP. Among aspirations, 10 (31.3%) of patients with emesis developed VAP compared with only 4 (12.5%) with blood in the airway (p=0.003).

CONCLUSION

Aspiration, along with depressed consciousness and greater injury severity, may predispose trauma patients to VAP. Prospective studies should focus on the quality and timing of aspiration relative to intubation to determine if novel interventions can prevent aspiration or decrease the risk of VAP after aspiration.

Critical care of traumatic spinal cord injury

Approximately 11 000 people suffer traumatic spinal cord injury (TSCI) in the United States, each year. TSCI incidences vary from 13.1 to 52.2 per million people and the mortality rates ranged from 3.1 to 17.5 per million people. This review examines the critical care of TSCI. The discussion will focus on primary and secondary mechanisms of injury, spine stabilization and immobilization, surgery, intensive care management, airway and respiratory management, cardiovascular complication management, venous thromboembolism, nutrition and glucose control, infection management, pressure ulcers and early rehabilitation, pharmacologic cord protection, and evolving treatment options including the use of pluripotent stem cells and hypothermia.

Attenuated hypocholesterolemia following severe trauma signals risk for late ventilator-associated pneumonia, ventilator dependency, and death: a retrospective study of consecutive patients

BACKGROUND

Post-traumatic ventilator-associated pneumonia (VAP) is a substantial clinical problem that increases hospital costs and typically adds to the duration of mechanical ventilation. We evaluated the impact of VAP on ventilator days. We also assessed 48-hour total blood cholesterol (TC) and other potential risk factors for the development of VAP.

METHODS

We performed a retrospective study of consecutive trauma patients requiring emergency tracheal intubation and evaluated TC, age, gender, ethanol status, smoker status, injury mechanism, chest injury, brain injury, Injury Severity Score (ISS), shock, day-one hypoxemia, and RBC transfusion as potential risks for VAP.

RESULTS

The 152 patients had ISS 28.1, brain injury 68.4%, VAP 50.0%, ventilator days 14.3, and death 9.9%. Ventilator days were increased with late VAP (p < 0.0001). TC was 110.7 mg/dL with expected TC 197.5 mg/dL. TC was lower with chest injury, shock, and RBC transfusion but, higher with brain injury (p ≤ 0.01). TC decreased as ISS increased (p = 0.01). However, one patient subset (ISS ≥ 20-&-TC ≥ 90 mg/dL) had a relative increase in TC despite an increase in ISS. ISS ≥ 20-&-TC ≥ 90 mg/dL, but not ISS alone, was the only independent predictor of late VAP (OR 3.0; p = 0.002). ISS ≥ 20-&-TC ≥ 90 mg/dL and day-one hypoxemia were the only independent predictors for increased ventilator days (p = 0.01). ISS ≥ 20-&-TC ≥ 90 mg/dL, but not ISS alone, was the only predictor of death (OR 3.8; p = 0.03).

CONCLUSIONS

Severe traumatic injury produced substantial hypocholesterolemia that is greater with chest injury, shock, and RBC transfusion, but less with brain injury. Total blood cholesterol tended to decrease with increasing injury severity. However, attenuated hypocholesterolemia (ISS ≥ 20-&-TC ≥ 90 mg/dL) represents a unique response that can occur with critical injury. Attenuated hypocholesterolemia signals early risk for late VAP, ventilator dependency, and death.

Anaesthetic and critical care management of thoracic injuries

Thoracic wounding has been a relatively common presentation of military wounds throughout modern conflict. When civilian casualties are included the incidence has remained constant at around 10%, although the frequency and severity of wounds to combatants has been altered by modern body armour. Whilst thoracic injury has a high initial mortality on the battlefield, those surviving to reach hospital frequently have injuries that only require simple management. In addition to penetrating ballistic injury, blunt chest trauma frequently occurs on operations as a result of road traffic collisions or tertiary blast injury. The physiological impact of thoracic wounds, however, is often great and survivors often require intensive care management and, where available, complex strategies to ensure oxygenation and carbon dioxide removal. This review examines the incidence and patterns of thoracic trauma and looks at therapeutic options for managing these complex cases.

A polyurethane cuffed endotracheal tube is associated with decreased rates of ventilator-associated pneumonia

PURPOSE

The aim of this study was to determine whether the use of a polyurethane-cuffed endotracheal tube would result in a decrease in ventilator-associated pneumonia rate.

MATERIALS AND METHODS

We replaced conventional endotracheal tube with a polyurethane-cuff endotracheal tube (Microcuff, Kimberly-Clark Corporation, Rosewell, Ga) in all adult mechanically ventilated patients throughout our large academic hospital from July 2007 to June 2008. We retrospectively compared the rates of ventilator-associated pneumonia before, during, and after the intervention year by interrupted time-series analysis.

RESULTS

Ventilator-associated pneumonia rates decreased from 5.3 per 1000 ventilator days before the use of the polyurethane-cuffed endotracheal tube to 2.8 per 1000 ventilator days during the intervention year (P = .0138). During the first 3 months after return to conventional tubes, the rate of ventilator-associated pneumonia was 3.5/1000 ventilator days. Use of the polyurethane-cuffed endotracheal tube was associated with an incidence risk ratio of ventilator-associated pneumonia of 0.572 (95% confidence interval, 0.340-0.963). In statistical regression analysis controlling for other possible alterations in the hospital environment, as measured by rate of tracheostomy-ventilator-associated pneumonia, the incidence risk ratio of ventilator-associated pneumonia in patients intubated with polyurethane-cuffed endotracheal tube was 0.565 (P = .032; 95% confidence interval, 0.335-0.953).

CONCLUSIONS

Use of a polyurethane-cuffed endotracheal tube was associated with a significant decrease in the rate of ventilator-associated pneumonia in our study.

The pathogen of ventilator-associated pneumonia does not influence the mortality rate of surgical intensive care unit patients treated with a rotational antibiotic system

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the leading causes of morbidity in critically ill surgical patients. Certain pathogens (e.g., methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa) have been associated with an excess mortality rate from sepsis in several studies, but not in the surgical setting specifically or when protocol-driven antibiotic therapy is administered.

PURPOSE

We sought to determine which factors and, in particular, whether the individual pathogen affected the mortality rate in our surgical intensive care unit (ICU), where a rotational antibiotic system has been employed continuously since 1997. We hypothesized that the type of pathogen and illness severity were the primary influences on the mortality rate of patients with VAP.

METHODS

A total of 198 consecutive patients from a university surgical ICU, with clinical signs of VAP confirmed by quantified isolation of significant numbers of a pathogen (> or =10(4) colony-forming units [cfu]/mL) from bronchoalveolar (BAL) fluid obtained by fiberoptic bronchoscopy, were identified prospectively from January 2001 to November 2004. The data collected were age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) III score, multiple organ dysfunction score, unit day of diagnosis, time (h) to antibiotic administration (TTA), appropriateness of initial therapy (AIT), unit and hospital length of stay, and mortality rate. Pathogens were classified as non-lactose-fermenting gram-negative bacilli (NGNB), lactose-fermenting gram-negative bacilli (LGNB), methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, yeast, community-acquired pneumonia (e.g., Streptococcus pneumoniae), or other pathogens. Patients with a polymicrobial isolate were placed in the "other" category.

RESULTS

The overall mortality rate was 32.3% vs. 55% as predicted by APACHE III normative data. The overall AIT was 92%. The mortality rate for NGNB infections was 35.6% vs. 29.4% for LGNB infections (p = NS). By logistic regression, neither TTA, AIT, nor pathogen influenced the mortality rate.

CONCLUSIONS

The type of pathogen does not influence death in surgical ICU patients with VAP diagnosed rigorously and treated by a rotational antibiotic system. The high proportion of AIT as a result of the rotational antibiotic administration system optimizes bacterial killing and negates the impact of bacterial resistance, contributing to better outcomes.

The Severity of Injury and the Extent of Hemorrhagic Shock Predict the Incidence of Infectious Complications in Trauma Patients

BACKGROUND

Trauma patients are at high risk of developing systemic inflammatory response syndrome (SIRS) and infections. The aim of this study was to evaluate the influence of the severity of injury and the extent of hemorrhagic shock at admission on the incidence of SIRS, infection and septic complications.

METHODS

A total of 972 patients who had an injury severity score (ISS) of ≥ 17, survived more than 72 h, and were admitted to a level I trauma center within 24 h after trauma were included in this retrospective analysis. SIRS, sepsis and infection rates were measured in patientswith different severities of injury as assessed by ISS, or with various degrees of hemorrhagic shock according to ATLS(®) guidelines, andwere compared using both uni- and multivariate analysis.

RESULTS

Infection rates and septic complications increase significantly (p < 0.001) with higher ISS. Severe hemorrhagic shock on admission is associated with a higher rate of infection (72.8%) and septic complications (43.2%) compared to mild hemorrhagic shock (43.4%, p < 0.001 and 21.7%, p < 0.001, respectively).

CONCLUSION

The severity of injury and the severity of hemorrhagic shock are risk factors for infectious and septic complications. Early diagnostic and adequate therapeutic work up with planned early "second look" interventions in such high-risk patients may help to reduce these common posttraumatic complications.

Pulmonary contusions and critical care management in thoracic trauma

Many victims of thoracic trauma require ICU care and mechanical ventilatory support. Pressure and volume-limited modes assist in the prevention of ventilator-associated lung injury. Ventilator-associated pneumonia is a significant cause of posttraumatic morbidity and mortality. Minimizing ventilator days, secretion control, early nutritional support, and patient positioning are methods to reduce the risk of pneumonia.

Aerosolized ceftazidime prophylaxis against ventilator-associated pneumonia in high-risk trauma patients: results of a double-blind randomized study

BACKGROUND

Ventilator-associated pneumonia (VAP) is a frequent complication during recovery of severely traumatized patients. The primary objective of this study was to determine if prophylactic administration of aerosolized ceftazidime reduced the incidence of VAP in high-risk injured patients without altering the incidence of other infectious complications.

PATIENTS AND METHODS

This was a single-institution double-blind, randomized trial that compared a seven-day course of aerosolized ceftazidime with placebo. Intubated high-risk patients admitted to the trauma intensive care unit at a large regional trauma center between February 2003 and September 2005 were eligible for enrollment. The main outcome evaluated was the incidence of VAP at two weeks and 30 days. The incidences of multi-drug-resistant infections and other infectious complications were secondary outcomes.

RESULTS

A total of 105 patients were randomized, resulting in 52 patients in the placebo arm and 53 patients in the ceftazidime arm. There was no statistical difference between the groups with regard to demographic data, injury severity, calculated risk of VAP, or the number of doses received. In the intention-to-treat analysis, the incidence of VAP at two weeks was 24/52 (46%) in the placebo group and 21/53 (40%) in the ceftazidime group. The number of patients with VAP at 30 days was 26/52 (50%) in the placebo group and 26/53 (49%) in the ceftazidime group. There was no statistical difference in the development of multi-drug-resistant VAP or other infectious complications in the two groups.

CONCLUSION

The use of aerosolized ceftazidime did not reduce the rate of VAP in high-risk patients admitted after traumatic injury, but neither did it increase the incidence of other infectious complications. Routine use of prophylactic aerosolized ceftazidime to prevent VAP in trauma patients cannot be recommended.

Aerosolised Antibacterials for the Prevention and Treatment of Hospital-Acquired Pneumonia

Aerosolised administration of antibacterials remains theoretically attractive for the prevention and treatment of hospital-acquired pneumonia (HAP) because of the ability to generate high drug concentrations at the site of infection. There is renewed interest in this area because of the shortcomings of current therapies and increasing multidrug resistance in Gram-negative organisms. Clinical trials of aerosolised or endotracheally administered antibacterials for HAP prevention have generally been positive; however, early trials were hampered by the development of resistance related to indiscriminate use. More recent trials have shown efficacy at HAP prevention without adverse effects on microflora as a result of more limited usage. However, prophylactic aerosolised antibacterials still need to be studied in large randomised trials before they could enter widespread use. The treatment of HAP with aerosolised antibacterials has mostly been reported in case series without control groups. Both early reports with aminoglycosides and the more recent use of colistin have reported very good response rates; even with organisms such as Pseudomonas aeruginosa and Acinetobacter baumannii. Aerosolised antibacterials were almost always added to intravenous therapy. On the basis of these reports, the current HAP guidelines allow the addition of aerosolised antibacterials in selected patients with multidrug-resistant organisms. This seems to be a reasonable recommendation until large trials are performed. Overall, toxicity was relatively low in the publications reviewed. Aerosolised drug administration in mechanically ventilated patients requires attention to a number of factors in order to maximise drug deposition in the lung.

Rib fractures: Relationship with pneumonia and mortality*

OBJECTIVE

In single-institution studies, age is a risk factor for mortality after rib fracture. Sample size has limited the assessment of other risk factors. We used a national database to analyze suspected risk factors contributing to pneumonia and mortality in patients sustaining rib fractures.

DESIGN

: Database analysis.

PATIENTS

All patients with rib fractures discharged from hospitals submitting information to the Nationwide Inpatient Sample database.

INTERVENTIONS

The 1999 Nationwide Inpatient Sample was queried for all patients with rib fracture. Age, gender, number of rib fractures, Injury Severity Score, comorbidities, pneumonia, and mortality were abstracted from the database. Comorbidities were scored according to Elixhauser. Multivariate analysis identified independent risk factors for mortality and pneumonia.

MEASUREMENTS AND MAIN RESULTS

We identified 23,426 patients; 17,308 patients had a primary diagnosis of trauma and were included in the analysis. Mean age was 56. Mean Injury Severity Score was 13.1. The number of comorbidities ranged from 0 to 9. Overall mortality was 4%. Six percent of patients had pneumonia. In a multivariate model, age and Injury Severity Score were significantly associated with both mortality and pneumonia. Comorbidity score was associated with pneumonia and mortality only in patients with isolated thoracic trauma. Pneumonia was associated with mortality only in patients with isolated thoracic trauma.

CONCLUSIONS

In a model controlling for multiple known risk factors, age and Injury Severity Score were the only important predictors of mortality in patients with rib fractures and multiple-system injury. Pneumonia was significantly associated with mortality only in patients with isolated thoracic trauma.

Ventilator-associated pneumonia, like real estate: location really matters

INTRODUCTION

Previous work has demonstrated an increased risk of ventilator-associated pneumonia (VAP) in trauma patients after prehospital (field) intubation as compared with emergency department (ED) intubations. However, this population was not compared with patients intubated as inpatients, making data interpretation difficult. We sought to further examine predictors for the development of VAP after trauma.

METHODS

A 10-year retrospective review of all patients mechanically ventilated greater than 24 hours after injury was performed.

RESULTS

In all, 1,628 patients were identified, of which 1,213 (75%) were intubated as inpatients and 415 were emergently intubated (353 ED, 62 field). Overall, those intubated emergently were younger (p = 0.03) and less injured as seen by higher Glasgow Coma Scale scores (p = 0.0002), lower Injury Severity Scores (p = 0.01) and higher Revised Trauma Scores (p < 0.0001). Despite a lower injury severity, those patients emergently intubated were more likely to develop pneumonia as 22% of ED intubations and 15% of field intubations developed pneumonia, as compared with the inpatient rate of 6.5%. Pneumonia after field intubation was more likely to be community-acquired (p < 0.0001) with a significantly lower percentage of infecting enteric gram-negative rods (p < 0.0001) as compared with the inpatient and ED groups. Forward logistic regression analysis (with VAP = 1) identified inpatient intubation as protective against VAP (odds ratio 0.28, 95% CI = 0.2-0.4). Backwards logistic regression analysis further identified both field airway (odds ratio 2.29, 95% CI = 1.1-4.9) and ED airway (odds ratio 3.61, 95% CI = 2.5-5.2) as predictive of VAP.

CONCLUSIONS

Compared with a population of trauma patients as inpatients, and excluding those patients mechanically ventilated less than 24 hours, patients intubated in the ED or field have a higher incidence of pneumonia, despite equivalent or lower injury severity.

Ventilator-associated pneumonia

PURPOSE OF REVIEW

This review summarises some of the notable papers on ventilator-associated pneumonia (VAP) from January 2003 to October 2004.

RECENT FINDINGS

Ventilator-associated pneumonia remains an important drain on hospital resources. All population groups are affected, but patients with VAP are more likely to be older, sicker, and male, with invasive medical devices in situ. Early VAP diagnosis is desirable to reduce VAP mortality and to retard emergence of multidrug-resistant microbes. This may be possible using preliminary culture results or intracellular organism in polymorphonuclear cells. In most intensive care units, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii are the commonest organisms isolated in VAP. However, causative organisms vary between and within hospitals. Consequently, individual intensive care units should develop empirical antibiotic policies to target the pathogenic bacteria prevalent in their patient populations. Preventative strategies aimed at reducing aerodigestive tract colonisation by pathogenic organisms, and also their subsequent aspiration, are becoming increasingly important. Educating medical staff about these simple measures is therefore pertinent. To reduce the occurrence of multidrug-resistant organisms, limiting the duration of antibiotic treatment to 8 days and antimicrobial rotation should be contemplated. Empirical therapy with antipseudomonal penicillins plus beta-lactamase inhibitors should be considered. If methicillin-resistant Staphylococcus aureus VAP is a possibility, linezolid may be better than vancomycin.

SUMMARY

Prevention remains the key to reducing VAP prevalence.

Urgent airways after trauma: who gets pneumonia?

BACKGROUND

Several risk factors, including emergent intubation, severe head injury, shock, blunt trauma, and high severity of injury, have been identified as risk factors for the development of pneumonia after trauma. This study assesses the contribution of emergent intubation to the development of pneumonia after injury.

METHODS

A retrospective review of all trauma patients requiring intubation or cricothyroidotomy in the Emergency Department (ED) or in the pre-hospital area (field) over a 41/2 year period.

RESULTS

571 patients comprised the study population. Of these, 80% had airways established in the ED, while 20% were intubated in the field. Field intubation was associated with a lower Glasgow Coma Scale (GCS) score (p <0.0001) and more severe injury (p <0.0001), particularly to the chest and extremities.Twenty-five percent of the population developed pneumonia. Patients diagnosed with pneumonia were older (p=0.009), and had a higher ISS (p <0.0001), lower GCS score, (p <0.008), longer ICU and hospital length of stay (p < 0.0001). Injuries to the head, thorax and extremities were more common (p < 0.05) and more severe (p <0.05) in patients developing pneumonia. The incidence of pneumonia after field airway was significantly higher (35% versus 23%, p=0.048).Multiple logistic regression analysis identified field intubation, age, AIS-head, and AIS-extremity as independent risk factors for pneumonia.

CONCLUSION

Pre-hospital but not ED intubation is an independent risk factor for the development of post-traumatic pneumonia. Other predictors include the severity of injury, specifically head and extremity injuries.

A novel model of pneumonia from intraperitoneal injection of bacteria

BACKGROUND

Pneumonia remains a major clinical problem in the surgical patient. Experimental modeling by intratracheal injection of bacteria is not consistently reproducible. In an attempt to produce peritonitis by Klebsiella, we found evidence of pneumonia on autopsy and further developed this approach as a new experimental model.

METHODS

Male Swiss Webster mice were given intraperitoneal (IP) injections of Klebsiella pneumoniae serotype 2 in different doses and this was compared with similar doses given intravenously (IV). A dose dependent survival curve was generated. Subsequently, 10(3) colony forming units (CFU) of bacteria were used in further experiments. Blood, peritoneal fluid and lung tissue were collected at time points up to 72 hours after injection and were cultured for levels of bacteria. Lung weights and myeloperoxidase levels were also measured.

RESULTS

Intraperitoneal administration of Klebsiella was uniformly lethal with as few as 10(2) bacteria. Lung weight increased after IP Klebsiella, and all animals became bacteremic within 24 hours correlating with high bacterial levels in the lung. Conversely, most animals (72%) survived IV injection of bacteria, and were able to clear bacteria from the blood and lung.

CONCLUSIONS

We found that this model produced no clinically apparent peritonitis after 48 hours, but uniformly resulted in histopathologic changes of pneumonia by 24 hours. Survival time was related to initial dose of Klebsiella and there was a linear correlation between bacterial levels in the blood and lung. This model is reproducible, simple to perform, and the severity is easy to manipulate.