Timing of intubation and ventilator-associated pneumonia following injury

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.

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.

Prehospital Supraglottic Airways: An NAEMSP Position Statement and Resource Document

Supraglottic airway (SGA) devices provide effective conduits for oxygenation and ventilation and may offer protection from gastric aspiration. SGA devices are widely used by EMS clinicians as both rescue and primary airway management devices. While in common use for more than four decades, major developments in SGA education, science, and technology have influenced clinical strategies of SGA insertion and use in prehospital airway management for patients of all ages. NAEMSP recommends:SGAs have utility as a primary or secondary EMS airway intervention. EMS agencies should select SGA strategies that best suit available resources and local clinician skillset, as well as the nature of their clinical practice setting.EMS agencies that perform endotracheal intubation must also equip their clinicians with SGA devices and ensure adequate training and competence.In select situations, drug-assisted airway management may be used by properly credentialed EMS clinicians to facilitate SGA insertion.Confirmation of initial and continuous SGA placement using waveform capnography is strongly encouraged as a best practice.When it is functioning properly, EMS clinicians should refrain from converting an SGA to an endotracheal tube. The decision to convert an SGA to an endotracheal tube must consider the patient's condition, the effectiveness of SGA ventilations, and the clinical context and course of initial SGA insertionSGA training, competency, and clinical use must be continuously evaluated by EMS agencies using focused quality management programs.

Machine Learning Model to Predict Ventilator Associated Pneumonia in patients with Traumatic Brain Injury: The C.5 Decision Tree Approach

BACKGROUND

There is paucity in the literature to predict the occurrence of Ventilator Associated Pneumonia (VAP) in patients with Traumatic Brain Injury (TBI). We aimed to build a C.5. Decision Tree (C.5 DT) machine learning model to predict VAP in patients with moderate to severe TBI.

METHODS

This was a retrospective study including all adult patients who were hospitalized with TBI plus head abbreviated injury scale (AIS) ≥ 3 and were mechanically ventilated in a level 1 trauma center between 2014 and 2019.

RESULTS

A total of 772 eligible patients were enrolled, of them 169 had VAP (22%). The C.5 DT model achieved moderate performance with 83.5% accuracy, 80.5% area under the curve, 71% precision, 86% negative predictive value, 43% sensitivity, 95% specificity and 54% F-score. Out of 24 predictors, C.5 DT identified 5 variables predicting occurrence of VAP post-moderate to severe TBI (Time from injury to emergency department arrival, blood transfusion during resuscitation, comorbidities, Injury Severity Score and pneumothorax).

CONCLUSIONS

This study could serve as baseline for the quest of predicting VAP in patients with TBI through the utilization of C.5. DT machine learning approach. This model helps provide timely decision support to caregivers to improve patient's outcomes.

Making Ventilator Associated Pneumonia Rate a Meaningful Quality Marker

INTRODUCTION

Ventilator associated pneumonia (VAP) rate has been tracked as a comparable quality measure but there is significant variation between types of ICUs. We sought to understand variability and improve its utility as a marker of quality.

METHODS

The National Trauma Database was surveyed to identify risk factors for VAP. Logistic regression, χ², Student's T-test or Mann-Whitney U test were used.

RESULTS

Risk factors associated with developing VAP were: injury severity score (ISS) (OR 1.03, 95% CI 1.03 -1.04), prehospital assisted respiration (PHAR) (OR 1.10, 1.03 -1.17), thoracic injuries (OR 2.28, 1.69-3.08), diabetes (OR 1.32, 1.20 -1.46), male gender (OR 1.38, 1.28 -1.60), care at a teaching hospital (OR 1.40, 1.29 -1.47) and unplanned intubation (OR 2.76, 2.52-3.03).

DISCUSSION

ISS, PHAR, diabetes, male gender, care at a teaching hospital and unplanned intubation are risk factors for the development of VAP. These factors should be accounted for in order to make VAP an effective quality marker.

Is prehospital endobronchial intubation a risk factor for subsequent ventilator associated pneumonia? A retrospective analysis

More than half of patients under mechanical ventilation in the intensive care unit (ICU) are field-intubated, which is a known risk factor for ventilator associated pneumonia (VAP). We assessed whether field endobronchial intubation (EBI) is associated with the development of subsequent VAP during the ICU stay. This retrospective, nested case-control study was conducted in a cohort of field-intubated patients admitted to an ICU of a teaching hospital during a three-year period. Cases were defined as field-intubated patients with EBI and controls corresponded to field-intubated patients with proper position of the tracheal tube on admission chest X-ray. Primary endpoint was the development of early VAP. Secondary endpoints included the development of early ventilator associated tracheo-bronchitis, late VAP, duration of mechanical ventilation, length of stay and mortality in the ICU. A total of 145 patients were studied (mean age: 54 ± 19 years; men: 74%). Reasons for field intubation were predominantly multiple trauma (49%) and cardiorespiratory arrest (38%). EBI was identified in 33 patients (23%). Fifty-three patients (37%) developed early or late VAP. EBI after field intubation was associated with a nearly two-fold increase of early VAP, though not statistically significant (30% vs. 17%: p = 0.09). No statistically significant difference was found regarding secondary outcomes. The present study suggests that inadvertent prehospital EBI could be associated with a higher incidence of early-onset VAP. Larger studies are required to confirm this hypothesis. Whether strategies aimed at decreasing the incidence and duration of EBI could reduce the incidence of subsequent VAP remains to be determined.

Preliminary Report: Comparing Aspiration Rates between Prehospital Patients Managed with Extraglottic Airway Devices and Endotracheal Intubation

INTRODUCTION

There has been a shift from endotracheal intubation (ETI) toward extraglottic devices (EGDs) for prehospital airway management. A concern exists that this may lead to more frequent cases of aspiration.

METHODS

This was a retrospective study using a prehospital quality assurance database. Patients were assigned to groups based on the method that ultimately managed their airways (EGD or ETI). Cases with documented blood/emesis obscuring the airway were considered inevitable aspiration cases and excluded. Aspiration was defined by the radiology report within 48 hours.

RESULTS

A total of 104 EGD and 152 ETI patients were identified. Aspiration data were available for 67 EGD and 94 ETI cases. Of those, 8 EGD and 3 ETI cases had blood/emesis obscuring the airway and were excluded as planned. After exclusions, there were 5 EGD and 11 ETI cases in which aspiration was later diagnosed (EGD aspiration rate = 8%, ETI aspiration rate = 12%; χ²: P = .359; relative risk = .841; 95% confidence interval, .329-2.152).

CONCLUSION

In this small quality assurance database, aspiration rates were not significantly different for prehospital patients managed with an EGD versus ETI.

World-Wide Variation in Incidence of Staphylococcus aureus Associated Ventilator-Associated Pneumonia: A Meta-Regression

Staphylococcus aureus (S. aureus) is a common Ventilator-Associated Pneumonia (VAP) isolate. The objective here is to define the extent and possible reasons for geographic variation in the incidences of S. aureus-associated VAP, MRSA-VAP and overall VAP. A meta-regression model of S. aureus-associated VAP incidence per 1000 Mechanical Ventilation Days (MVD) was undertaken using random effects methods among publications obtained from a search of the English language literature. This model incorporated group level factors such as admission to a trauma ICU, year of publication and use of bronchoscopic sampling towards VAP diagnosis. The search identified 133 publications from seven worldwide regions published over three decades. The summary S. aureus-associated VAP incidence was 4.5 (3.9–5.3) per 1000 MVD. The highest S. aureus-associated VAP incidence is amongst reports from the Mediterranean (mean; 95% confidence interval; 6.1; 4.1–8.5) versus that from Asian ICUs (2.1; 1.5–3.0). The incidence of S. aureus-associated VAP varies by up to three-fold (for the lowest versus highest incidence) among seven geographic regions worldwide, whereas the incidence of VAP varies by less than two-fold. Admission to a trauma unit is the most important group level correlate for S. aureus-associated VAP.

Unusually High Incidences of Staphylococcus aureus Infection within Studies of Ventilator Associated Pneumonia Prevention Using Topical Antibiotics: Benchmarking the Evidence Base

Selective digestive decontamination (SDD, topical antibiotic regimens applied to the respiratory tract) appears effective for preventing ventilator associated pneumonia (VAP) in intensive care unit (ICU) patients. However, potential contextual effects of SDD on Staphylococcus aureus infections in the ICU remain unclear. The S. aureus ventilator associated pneumonia (S. aureus VAP), VAP overall and S. aureus bacteremia incidences within component (control and intervention) groups within 27 SDD studies were benchmarked against 115 observational groups. Component groups from 66 studies of various interventions other than SDD provided additional points of reference. In 27 SDD study control groups, the mean S. aureus VAP incidence is 9.6% (95% CI; 6.9–13.2) versus a benchmark derived from 115 observational groups being 4.8% (95% CI; 4.2–5.6). In nine SDD study control groups the mean S. aureus bacteremia incidence is 3.8% (95% CI; 2.1–5.7) versus a benchmark derived from 10 observational groups being 2.1% (95% CI; 1.1–4.1). The incidences of S. aureus VAP and S. aureus bacteremia within the control groups of SDD studies are each higher than literature derived benchmarks. Paradoxically, within the SDD intervention groups, the incidences of both S. aureus VAP and VAP overall are more similar to the benchmarks.

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.

A systematic review and meta-analysis comparing mortality in pre-hospital tracheal intubation to emergency department intubation in trauma patients

Background

Pre-hospital endotracheal intubation is frequently used for trauma patients in many emergency medical systems. Despite a wide range of publications in the field, it is debated whether the intervention is associated with a favourable outcome, when compared to more conservative airway measures.

Methods

A systematic literature search was conducted to identify interventional and observational studies where the mortality rates of adult trauma patients undergoing pre-hospital endotracheal intubation were compared to those undergoing emergency department intubation.

Results

Twenty-one studies examining 35,838 patients were included. The median mortality rate in patients undergoing pre-hospital intubation was 48% (range 8–94%), compared to 29% (range 6–67%) in patients undergoing intubation in the emergency department. Odds ratios were in favour of emergency department intubation both in crude and adjusted mortality, with 2.56 (95% CI: 2.06, 3.18) and 2.59 (95% CI: 1.97, 3.39), respectively. The overall quality of evidence is very low. Twelve of the twenty-one studies found a significantly higher mortality rate after pre-hospital intubation, seven found no significant differences, one found a positive effect, and for one study an analysis of the mortality rate was beyond the scope of the article.

Conclusions

The rationale for wide and unspecific indications for pre-hospital intubation seems to lack support in the literature, despite several publications involving a relatively large number of patients. Pre-hospital intubation is a complex intervention where guidelines and research findings should be approached cautiously. The association between pre-hospital intubation and a higher mortality rate does not necessarily contradict the importance of the intervention, but it does call for a thorough investigation by clinicians and researchers into possible causes for this finding.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1787-x) contains supplementary material, which is available to authorized users.

Prehospital oral chlorhexidine does not reduce the rate of ventilator-associated pneumonia among critically ill trauma patients: A prospective concurrent-control study

PURPOSE

The purpose of the study was to test the hypothesis that prehospital oral chlorhexidine administered to intubated trauma patients will decrease the Clinical Pulmonary Infection Score (CPIS) during the first 2 days of hospitalization.

MATERIALS AND METHODS

Prospective interventional concurrent-control study of all intubated adult trauma patients transported by air ambulance to a 711-bed Midwestern academic trauma center over a 1-year period. Patients transported by 2 university-based helicopters were treated with oral chlorhexidine after intubation, and the control group was patients transported by other air transport services.

RESULTS

Sixty-seven patients were enrolled, of which 23 received chlorhexidine (9 patients allocated to the intervention were not treated). The change in CPIS score was no different between the intervention and control groups by intention to treat (1.06- vs 1.40-point reduction, P = .520), and no difference was observed in tracheal colonization (29.0% vs 36.7%, P = .586). No differences were observed in the rate of clinical pneumonia (8.7% vs 8.6%, P = .987) or mortality (P = .196) in the per-protocol chlorhexidine group.

CONCLUSIONS

The prehospital administration of oral chlorhexidine does not reduce the CPIS score over the first 48 hours of admission for intubated trauma patients. Further study should explore other prehospital strategies of reducing complications of critical illness.

Infection prevention in the emergency department

Infection prevention remains a major challenge in emergency care. Acutely ill and injured patients seeking evaluation and treatment in the emergency department (ED) not only have the potential to spread communicable infectious diseases to health care personnel and other patients, but are vulnerable to acquiring new infections associated with the care they receive. This article will evaluate these risks and review the existing literature for infection prevention practices in the ED, ranging from hand hygiene, standard and transmission-based precautions, health care personnel vaccination, and environmental controls to strategies for preventing health care-associated infections. We will conclude by examining what can be done to optimize infection prevention in the ED and identify gaps in knowledge where further research is needed. Successful implementation of evidence-based practices coupled with innovation of novel approaches and technologies tailored specifically to the complex and dynamic environment of the ED are the keys to raising the standard for infection prevention and patient safety in emergency care.

Duration of prehospital intubation is not a risk factor for development of early ventilator-associated pneumonia

PURPOSE

Ventilator-associated pneumonia (VAP) is a significant cause of morbidity and mortality among critically ill patients with trauma. Few VAP prevention strategies have been studied in the prehospital environment. The objectives of this study are to measure the association between duration of prehospital intubation and intubation location with subsequent incidence of early (within 5 days) VAP.

MATERIALS AND METHODS

Single-center retrospective cohort study of all intubated adult (age≥18 years) patients with trauma presenting to a 711-bed Midwestern Level I trauma center between January 2005 and December 2011 (n=860).

RESULTS

Thirty-five patients (6.4%) were diagnosed as having early VAP during the study period. Using multivariable logistic regression to adjust for age, injury severity score, and year (corresponding to VAP bundle implementation), the duration of intubation prior to hospital admission was not associated with subsequent diagnosis of VAP (adjusted odds ratio, 0.90 per hour; 95% confidence interval, 0.70-1.15). Location of intubation was similarly not associated with VAP.

CONCLUSIONS

Duration of prehospital intubation and intubation location were not different in patients with trauma who developed early VAP. Further prospective analyses should be conducted to better elucidate the effect of prehospital management on the development of traditionally in-hospital complications.

High incidence of post-injury pneumonia in intensive care-treated trauma patients

INTRODUCTION

Trauma patients are susceptible to post-injury infections. We investigated the incidence, as well as risk factors for development of pneumonia in intensive care unit (ICU)-treated trauma patients. In addition, we report pathogens identified in patients that developed pneumonia.

METHODS

The study cohort consisted of 322 trauma patients admitted to the ICU at a level-one trauma centre following initial resuscitation. Patients 15 years or older with an ICU stay of more than 24 h were included. We investigated pre-hospital and hospital parameters during the first 24 h after admission and their possible association with pneumonia within 10 days of ICU admission.

RESULTS

Majority of the patients were male (78%) and the median age was 41 years. The overall degree of injury was high with a median Injury Severity Score (ISS) of 24. Overall 30-day mortality was 9%. Eighty-five (26%) patients developed pneumonia during their first 10 days in the ICU. Univariate logistic regression revealed that intubation in the field, shock, Glasgow Coma Scale (GCS) 3-8, major surgery within 24 h after admission, massive transfusion and ISS > 24 were all risk factors for subsequent development of pneumonia. In the multivariable model, only GCS 3-8 was identified as an independent risk factor. In 42 out of the 85 cases of pneumonia, the diagnosis was defined by significant growth of at least one pathogen where Enterobacteriaceae and Staphylococcus aureus were the most common.

CONCLUSIONS

Pneumonia is a common complication among ICU-treated trauma patients. Reduced consciousness is an independent risk factor for development of pneumonia after severe injury.

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.