Accuracy of the clinical pulmonary infection score to differentiate ventilator-associated tracheobronchitis from ventilator-associated pneumonia

A respiratory critical care nurse training program for settings without a registered respiratory therapists: A protocol for a multimethod study

BACKGROUND

The increasing elderly population and prevalence of chronic diseases have raised the need for ICU beds. However, limited bed availability often causes delays in admission, leading to wasted treatment time.

OBJECTIVES

This study aims to create and implement a training program for respiratory critical care nurses (RCCNs) in settings without registered respiratory therapists (RRTs).

RESEARCH

METHODOLOGY/DESIGN

The study will use a multimethod sequential research design, including a scoping review, content analysis, Delphi methods, and a randomized clinical trial. The scoping review will gather extensive information on respiratory care for critically ill patients and the responsibilities of RCCNs. Content analysis and expert interviews will identify opportunities and challenges in RCCNs' provision of respiratory care. The Delphi method will integrate the results to develop a comprehensive training program for RCCNs. Subsequently, five RCCNs will undergo theoretical and practical examinations after completing the three-month training program, and the impact of RCCNs on critically ill patients' outcomes will be evaluated through a clinical trial.

ANTICIPATED FINDINGS

The study aims to provide a comprehensive training program for RCCNs and investigate its impact on the outcomes of critically ill patients through a clinical trial.

CONCLUSION

The training program will equip RCCNs with the necessary skills and knowledge to provide respiratory critical care from the emergency department to hospital discharge. This pioneering study aims to improve patient outcomes in settings without RRTs by offering a unique program for RCCNs.

IMPLICATIONS FOR CLINICAL PRACTICE

The development and implementation of this training program for RCCNs in settings without RRTs will address the gap in respiratory care and potentially improve patient outcomes. By empowering RCCNs with specialized training, healthcare facilities can ensure the provision of high-quality respiratory care throughout a patient's critical illness journey, enhancing the efficiency and effectiveness of healthcare teams, especially in resource-limited settings.

Outcomes of High-Dose Versus Low-Dose Vitamin D on Prognosis of Sepsis Requiring Mechanical Ventilation: A Randomized Controlled Trial

Background: Critically ill patients with sepsis have a high incidence of vitamin D deficiency. Vitamin D promotes the synthesis of human cathelicidin antimicrobial peptide, a precursor of LL-37, which is a part of the innate immune system. This study investigated the effectiveness and safety of the early administration of high-dose enteral vitamin D3 in comparison with low-dose vitamin D3 in patients with sepsis requiring mechanical ventilation (MV). Methods: Eighty adult patients with sepsis requiring MV with known vitamin D deficiency were randomly assigned to receive either an enteral 50 000 IU (Group I) or 5000 IU (Group II) vitamin D supplementation. Clinical and laboratory parameters were evaluated at baseline and on days 4 and 7 between the study groups. The change in serum procalcitonin (PCT) levels on day 7 was the primary outcome, while the change in serum LL-37 levels on day 7, changes in sequential organ failure assessment (SOFA) score, and clinical pulmonary infection score on day 7, MV duration, and hospital length of stay (LOS) were the secondary outcomes. Results: The (day 7-day 0) change in serum PCT and LL-37 levels and SOFA score were significantly different in Group I (P = .010, P < .001, and P < .001, respectively). The SOFA score was significantly different on days 4 and 7 in Group I (P < .001 and P < .001, respectively). The incidence of early ventilator-associated pneumonia was significantly different between both treatment groups (P = .025). The hospital LOS was shorter in Group I (P < .001). No 25-hydroxyvitamin-D toxicity was observed in either group. Conclusions: Early enteral administration of high-dose vitamin D3 in critically ill patients with sepsis requiring MV along with standard treatment for sepsis decreased serum procalcitonin levels, increased serum LL-37 levels, and ameliorated illness severity scores.

Predicting pneumonia during hospitalization in flail chest patients using machine learning approaches

Objective

Pneumonia is a common pulmonary complication of flail chest, causing high morbidity and mortality rates in affected patients. The existing methods for identifying pneumonia have low accuracy, and their use may delay antimicrobial therapy. However, machine learning can be combined with electronic medical record systems to identify information and assist in quick clinical decision-making. Our study aimed to develop a novel machine-learning model to predict pneumonia risk in flail chest patients.

Methods

From January 2011 to December 2021, the electronic medical records of 169 adult patients with flail chest at a tertiary teaching hospital in an urban level I Trauma Centre in Chongqing were retrospectively analysed. Then, the patients were randomly divided into training and test sets at a ratio of 7:3. Using the Fisher score, the best subset of variables was chosen. The performance of the seven models was evaluated by computing the area under the receiver operating characteristic curve (AUC). The output of the XGBoost model was shown using the Shapley Additive exPlanation (SHAP) method.

Results

Of 802 multiple rib fracture patients, 169 flail chest patients were eventually included, and 86 (50.80%) were diagnosed with pneumonia. The XGBoost model performed the best among all seven machine-learning models. The AUC of the XGBoost model was 0.895 (sensitivity: 84.3%; specificity: 80.0%).Pneumonia in flail chest patients was associated with several features: systolic blood pressure, pH value, blood transfusion, and ISS.

Conclusion

Our study demonstrated that the XGBoost model with 32 variables had high reliability in assessing risk indicators of pneumonia in flail chest patients. The SHAP method can identify vital pneumonia risk factors, making the XGBoost model's output clinically meaningful.

Including Organ Dysfunctions in a Predictive Score for Nosocomial Pneumonia After Cardiothoracic Surgery

BACKGROUND

Clinical diagnosis of ICU-acquired pneumonia after cardiothoracic surgery is challenging. Johanson criteria (chest radiograph infiltrate, purulent tracheal secretions, fever, and leukocytosis) fail in half the cases. A high Clinical Pulmonary Infection Score (CPIS) and ≥ 2-point increase in Sequential Organ Failure Assessment (SOFA) score (SOFA↑ ≥ 2) may improve diagnosis. The aim of the study was to evaluate whether CPIS or SOFA↑ ≥ 2 contributes to predict ICU-acquired pneumonia in subjects after cardiothoracic surgery.

METHODS

We used a prospective observational design. Spiegelhalter-Knill-Jones scoring systems including CPIS or SOFA↑ ≥ 2, together with other clinical and laboratory variables, were developed in a derivation cohort. A positive quantitative pulmonary sample culture was required to confirm ICU-acquired pneumonia. Area under the receiver operating characteristic curve (AUROC) was computed for each of the 2 scoring systems. The best system was evaluated in a validation cohort.

RESULTS

Derivation and validation cohorts included 172 and 108 subjects, with 410 and 216 suspected ICU-acquired pneumonia episodes, respectively. AUROC was 0.53 ± 0.03 for CPIS (P = .29) and 0.54 ± 0.03 for SOFA↑ ≥ 2 (P = .29). Adding purulent tracheal secretions and leukocytosis to SOFA↑ ≥ 2 (SOFA model) increased AUROC to 0.65 ± 0.03 (P < .001). Adding catecholamine use to CPIS (CPIS model) increased AUROC only slightly, to 0.57 ± 0.03. The probabilities predicted by the SOFA model were reliable, especially when high or low.

CONCLUSIONS

A clinical scoring system including at least SOFA↑ ≥ 2 increase barely improved ICU-acquired pneumonia prediction in subjects after cardiothoracic surgery.

Early prediction of ventilator-associated pneumonia in critical care patients: a machine learning model

Background

This study was performed to develop and validate machine learning models for early detection of ventilator-associated pneumonia (VAP) 24 h before diagnosis, so that VAP patients can receive early intervention and reduce the occurrence of complications.

Patients and methods

This study was based on the MIMIC-III dataset, which was a retrospective cohort. The random forest algorithm was applied to construct a base classifier, and the area under the receiver operating characteristic curve (AUC), sensitivity and specificity of the prediction model were evaluated. Furthermore, We also compare the performance of Clinical Pulmonary Infection Score (CPIS)-based model (threshold value ≥ 3) using the same training and test data sets.

Results

In total, 38,515 ventilation sessions occurred in 61,532 ICU admissions. VAP occurred in 212 of these sessions. We incorporated 42 VAP risk factors at admission and routinely measured the vital characteristics and laboratory results. Five-fold cross-validation was performed to evaluate the model performance, and the model achieved an AUC of 84% in the validation, 74% sensitivity and 71% specificity 24 h after intubation. The AUC of our VAP machine learning model is nearly 25% higher than the CPIS model, and the sensitivity and specificity were also improved by almost 14% and 15%, respectively.

Conclusions

We developed and internally validated an automated model for VAP prediction using the MIMIC-III cohort. The VAP prediction model achieved high performance based on its AUC, sensitivity and specificity, and its performance was superior to that of the CPIS model. External validation and prospective interventional or outcome studies using this prediction model are envisioned as future work.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02031-w.

A Narrative Review on the Approach to Antimicrobial Use in Ventilated Patients with Multidrug Resistant Organisms in Respiratory Samples—To Treat or Not to Treat? That Is the Question

Multidrug resistant organisms (MDRO) are commonly isolated in respiratory specimens taken from mechanically ventilated patients. The purpose of this narrative review is to discuss the approach to antimicrobial prescription in ventilated patients who have grown a new MDRO isolate in their respiratory specimen. A MEDLINE and PubMed literature search using keywords “multidrug resistant organisms”, “ventilator-associated pneumonia” and “decision making”, “treatment” or “strategy” was used to identify 329 references as background for this review. Lack of universally accepted diagnostic criteria for ventilator-associated pneumonia, or ventilator-associated tracheobronchitis complicates treatment decisions. Consideration of the clinical context including signs of respiratory infection or deterioration in respiratory or other organ function is essential. The higher the quality of respiratory specimens or the presence of bacteremia would suggest the MDRO is a true pathogen, rather than colonization, and warrants antimicrobial therapy. A patient with higher severity of illness has lower safety margins and may require initiation of antimicrobial therapy until an alternative diagnosis is established. A structured approach to the decision to treat with antimicrobial therapy is proposed.

Values of PCT and STREM-1 combined with clinical pulmonary infection score for the prognostic evaluation of elderly patients with ventilator-associated pneumonia

Objective: To explore the values of PCT and STREM-1 combined with clinical pulmonary infection score (CPIS) for evaluating ventilator-associated pneumonia (VAP) in elderly patients.

Methods: A total of 120 eligible patients were selected as VAP group, and 60 other patients without VAP were selected as control group. According to APACHE II scores, VAP group was divided into low-, medium-, and high-risk groups. The correlations of PCT, STREM-1, and CPIS with APACHE II score were analyzed. The values of PCT and STREM-1 combined with CPIS for evaluating prognosis were analyzed using ROC curves.

Results: In the VAP group, serum PCT and STREM-1 levels and CPIS after mechanical ventilation significantly exceeded those of the control group and before mechanical ventilation (P<0.05). These values were higher in the high-risk group than in medium- and low-risk groups (P<0.05). They were positively correlated with APACHE II score (P<0.001). These values of the death group were significantly higher than those of the survival group 1, 3, 5, and 7 d after treatment (P<0.05). AUC of PCT and STREM-1 combined with CPIS for assessing prognosis was 0.892 (P<0.001).

Conclusions: Serum PCT and STREM-1 levels and CPIS significantly increase in elderly patients with VAP, which rise with aggravation. Their combination has higher values for prognostic evaluation.

Effect of antibiotic therapy on the prognosis of ventilator-associated pneumonia caused by Stenotrophomonas maltophilia

BACKGROUND

Ventilator-associated pneumonia (VAP) caused by Stenotrophomonas maltophilia is poorly described in the literature. However, it has been shown to be associated with increased morbidity and mortality. Probabilistic antibiotic therapy against S. maltophilia is often ineffective as this pathogen is resistant to many antibiotics. There is no consensus at present on the best therapeutic strategy to adopt (class of antibiotics, antibiotic combination, dosage, treatment duration). The aim of this study was to evaluate the effect of antibiotic therapy strategy on the prognosis of patients with VAP caused by S. maltophilia.

RESULTS

This retrospective study evaluated all consecutive patients who developed VAP caused by S. maltophilia between 2010 and 2018 while hospitalized in the intensive care unit (ICU) of a French university hospital in Reunion Island, in the Indian Ocean region. A total of 130 patients with a median Simplified Acute Physiology Score II of 58 [43-73] had VAP caused by S. maltophilia after a median duration of mechanical ventilation of 12 [5-18] days. Ventilator-associated pneumonia was polymicrobial in 44.6% of cases, and ICU mortality was 50.0%. After multivariate Cox regression analysis, the factors associated with increased ICU mortality were older age (hazard ratio (HR): 1.03; 95% CI 1.01-1.04, p = 0.001) and high Sequential Organ Failure Assessment score on the day of VAP onset (HR: 1.08; 95% CI 1.03-1.14, p = 0.002). Appropriate antibiotic therapy, and in particular trimethoprim-sulfamethoxazole, was associated with decreased ICU mortality (HR: 0.42; 95% CI 0.24-0.74, p = 0.003) and decreased hospital mortality (HR: 0.47; 95% CI 0.28-0.79, p = 0.04). Time to start of appropriate antibiotic therapy, combination therapy, and duration of appropriate antibiotic therapy had no effect on ICU mortality (p > 0.5).

CONCLUSION

In our study, appropriate antibiotic therapy, and in particular trimethoprim-sulfamethoxazole, was associated with decreased ICU and hospital mortality in patients with VAP caused by S. maltophilia.

Clinical features of Mycoplasma pneumoniae pneumonia with adenovirus infection in children

OBJECTIVES

To study the clinical features of Mycoplasma pneumoniae pneumonia (MPP) with adenovirus (ADV) infection in children.

METHODS

A retrospective analysis was performed on the medical data of 228 children with MPP alone and 28 children with MPP and ADV infection. The two groups were compared in terms of clinical features, laboratory results, and treatment outcome.

RESULTS

Compared with the MPP group, the MPP+ADV group had significantly longer duration of fever and length of hospital stay, a significantly higher proportion of patients with severe lesions (erosion and exfoliation) of the airway mucosa under bronchoscopy, a significantly higher clinical pulmonary infection score, and a significantly higher proportion of patients requiring oxygen therapy (P<0.05). There were no significant differences between the two groups in white blood cell count, C-reactive protein, Mycoplasma pneumoniae DNA copy number in bronchoalveolar lavage fluid, and the incidence rates of pleural effusion and extrapulmonary complications (P>0.05).

CONCLUSIONS

Compared with children with MPP alone, children with MPP and ADV infection tend to have more severe clinical manifestations and airway mucosal lesions and are more likely to require oxygen therapy, but most of the laboratory markers lack specificity.

Extended Lung Ultrasound to Differentiate Between Pneumonia and Atelectasis in Critically Ill Patients: A Diagnostic Accuracy Study

OBJECTIVES

To determine the diagnostic accuracy of extended lung ultrasonographic assessment, including evaluation of dynamic air bronchograms and color Doppler imaging to differentiate pneumonia and atelectasis in patients with consolidation on chest radiograph. Compare this approach to the Simplified Clinical Pulmonary Infection Score, Lung Ultrasound Clinical Pulmonary Infection Score, and the Bedside Lung Ultrasound in Emergency protocol.

DESIGN

Prospective diagnostic accuracy study.

SETTING

Adult ICU applying selective digestive decontamination.

PATIENTS

Adult patients that underwent a chest radiograph for any indication at any time during admission. Patients with acute respiratory distress syndrome, coronavirus disease 2019, severe thoracic trauma, and infectious isolation measures were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Lung ultrasound was performed within 24 hours of chest radiograph. Consolidated tissue was assessed for presence of dynamic air bronchograms and with color Doppler imaging for presence of flow. Clinical data were recorded after ultrasonographic assessment. The primary outcome was diagnostic accuracy of dynamic air bronchogram and color Doppler imaging alone and within a decision tree to differentiate pneumonia from atelectasis. Of 120 patients included, 51 (42.5%) were diagnosed with pneumonia. The dynamic air bronchogram had a 45% (95% CI, 31-60%) sensitivity and 99% (95% CI, 92-100%) specificity. Color Doppler imaging had a 90% (95% CI, 79-97%) sensitivity and 68% (95% CI, 56-79%) specificity. The combined decision tree had an 86% (95% CI, 74-94%) sensitivity and an 86% (95% CI, 75-93%) specificity. The Bedside Lung Ultrasound in Emergency protocol had a 100% (95% CI, 93-100%) sensitivity and 0% (95% CI, 0-5%) specificity, while the Simplified Clinical Pulmonary Infection Score and Lung Ultrasound Clinical Pulmonary Infection Score had a 41% (95% CI, 28-56%) sensitivity, 84% (95% CI, 73-92%) specificity and 68% (95% CI, 54-81%) sensitivity, 81% (95% CI, 70-90%) specificity, respectively.

CONCLUSIONS

In critically ill patients with pulmonary consolidation on chest radiograph, an extended lung ultrasound protocol is an accurate and directly bedside available tool to differentiate pneumonia from atelectasis. It outperforms standard lung ultrasound and clinical scores.

Relationship of Multiplex Molecular Pneumonia Panel Results With Hospital Outcomes and Clinical Variables

Background

Antibiotic treatment decisions in severely ill patients must often be made in the absence of microbiologic results. The recently Food and Drug Administration-cleared BioFire FilmArray Pneumonia Panel (PN) detects 15 bacteria semiquantitatively, 3 atypical pneumonia bacteria, 8 viruses, and 7 antimicrobial resistance markers by multiplex PCR in ~1 hour in the laboratory. Previous reports have shown that the PN Panel bacterial detections are highly accurate, even when routine culture had no growth.

Methods

Consecutive bronchoalveolar lavage and endotracheal specimens submitted for culture between June and September 2018 from 270 patients with sufficient clinical and laboratory data were tested with the PN Panel. Patients were divided into 3 groups: (1) both culture and PN Panel positive, (2) PN Panel positive but culture uninformative (no growth or normal flora), and (3) patients with no PN Panel detections.

Results

Groups 1 and 2 had significantly higher maximum temperatures on the day of culture (P = .00036, analysis of variance [ANOVA] with Bonferroni correction), higher levels of an inflammatory response as measured by percent polymorphonuclear leukocytes in bronchoalveolar lavage (P = .00025, ANOVA with Bonferroni correction), and gram stain report of white blood cells, as previously reported [1].

Conclusions

Both group 1 (culture and PN Panel positive), and group 2 (PN Panel positive but culture uninformative) had higher levels of host response inflammatory responses compared with group 3, which had no targets detected, suggesting that PN Panel detections need to be interpreted in the clinical context, even if cultures are discordant. Depending on laboratory turnaround time, there could be opportunities for improved diagnosis and antibiotic stewardship.

Airway Pseudomonas aeruginosa density in mechanically ventilated patients: clinical impact and relation to therapeutic efficacy of antibiotics

Background

The bacterial density of Pseudomonas aeruginosa is closely related to its pathogenicity. We evaluated the effect of airway P. aeruginosa density on the clinical course of mechanically ventilated patients and the therapeutic efficacy of antibiotics.

Methods

We retrospectively analyzed data of mechanically ventilated ICU patients with P. aeruginosa isolated from endotracheal aspirates. Patients were divided into three groups according to the peak P. aeruginosa density during ICU stay: low (≤ 10⁴ cfu/mL), moderate (10⁵‒10⁶ cfu/mL), and high (≥ 10⁷ cfu/mL) peak density groups. The relationship between peak P. aeruginosa density and weaning from mechanical ventilation, risk factors for isolation of high peak density of P. aeruginosa, and antibiotic efficacy were investigated using multivariate and propensity score-matched analyses.

Results

Four-hundred-and-sixty-one patients were enrolled. Patients with high peak density of P. aeruginosa had higher inflammation and developed more severe respiratory infections. High peak density of P. aeruginosa was independently associated with few ventilator-free days on day 28 (P < 0.01) and increased ICU mortality (P = 0.047). Risk factors for high peak density of P. aeruginosa were prolonged mechanical ventilation (odd ratio [OR] 3.07 95% confidence interval [CI] 1.35‒6.97), non-antipseudomonal cephalosporins (OR 2.17, 95% CI 1.35‒3.49), hyperglycemia (OR 2.01, 95% CI 1.26‒3.22) during ICU stay, and respiratory diseases (OR 1.9, 95% CI 1.12‒3.23). Isolation of commensal colonizer was associated with lower risks of high peak density of P. aeruginosa (OR 0.43, 95% CI 0.26‒0.73). Propensity score-matched analysis revealed that antibiotic therapy for patients with ventilator-associated tracheobronchitis improved weaning from mechanical ventilation only in the high peak P. aeruginosa group.

Conclusions

Patients with high peak density of P. aeruginosa had worse ventilator outcome and ICU mortality. In patients with ventilator-associated tracheobronchitis, antibiotic therapy was associated with favorable ventilator weaning only in the high peak P. aeruginosa density group, and bacterial density could be a good therapeutic indicator for ventilator-associated tracheobronchitis due to P. aeruginosa.