An international RAND/UCLA expert panel to determine the optimal diagnosis and management of burn inhalation injury.

BACKGROUND: Burn inhalation injury (BII) is a major cause of burn-related mortality and morbidity. Despite published practice guidelines, no consensus exists for the best strategies regarding diagnosis and management of BII. A modified DELPHI study using the RAND/UCLA (University of California, Los Angeles) Appropriateness Method (RAM) systematically analysed the opinions of an expert panel. Expert opinion was combined with available evidence to determine what constitutes appropriate and inappropriate judgement in the diagnosis and management of BII. METHODS: A 15-person multidisciplinary panel comprised anaesthetists, intensivists and plastic surgeons involved in the clinical management of major burn patients adopted a modified Delphi approach using the RAM method. They rated the appropriateness of statements describing diagnostic and management options for BII on a Likert scale. A modified final survey comprising 140 statements was completed, subdivided into history and physical examination (20), investigations (39), airway management (5), systemic toxicity (23), invasive mechanical ventilation (29) and pharmacotherapy (24). Median appropriateness ratings and the disagreement index (DI) were calculated to classify statements as appropriate, uncertain, or inappropriate. RESULTS: Of 140 statements, 74 were rated as appropriate, 40 as uncertain and 26 as inappropriate. Initial intubation with ≥ 8.0 mm endotracheal tubes, lung protective ventilatory strategies, initial bronchoscopic lavage, serial bronchoscopic lavage for severe BII, nebulised heparin and salbutamol administration for moderate-severe BII and N-acetylcysteine for moderate BII were rated appropriate. Non-protective ventilatory strategies, high-frequency oscillatory ventilation, high-frequency percussive ventilation, prophylactic systemic antibiotics and corticosteroids were rated inappropriate. Experts disagreed (DI ≥ 1) on six statements, classified uncertain: the use of flexible fiberoptic bronchoscopy to guide fluid requirements (DI = 1.52), intubation with endotracheal tubes of internal diameter < 8.0 mm (DI = 1.19), use of airway pressure release ventilation modality (DI = 1.19) and nebulised 5000IU heparin, N-acetylcysteine and salbutamol for mild BII (DI = 1.52, 1.70, 1.36, respectively). CONCLUSIONS: Burns experts mostly agreed on appropriate and inappropriate diagnostic and management criteria of BII as in published guidance. Uncertainty exists as to the optimal diagnosis and management of differing grades of severity of BII. Future research should investigate the accuracy of bronchoscopic grading of BII, the value of bronchial lavage in differing severity groups and the effectiveness of nebulised therapies in different severities of BII.

Persistent isolated impairment of gas transfer following COVID-19 pneumonitis relates to perfusion defects on dual-energy computed tomography.

A novel iodine perfusion score correlates with breathlessness and D LCO in patients post-#COVID19 without obvious interstitial disease on CT, suggesting that lung perfusion assessment may be useful in patients without another cause of dyspnoea https://bit.ly/3U6E2f5.

Impact of inhalation injury on outcomes in critically ill burns patients: 12-year experience at a regional burns centre.

INTRODUCTION: Burns inhalation injury increases the attributable mortality of burns related trauma. However, diagnostic uncertainties around bronchoscopically graded severity, and its effect on outcomes, remain. This study evaluated the impact of different bronchoscopic burns inhalation injury grades on outcomes. METHODS: A single-centre cohort study of all patients admitted to the London Burns centre intensive care unit (BICU) over 12 years. Demographic data, burn and burns inhalation injury characteristics, and ICU-related parameters were collected retrospectively. The primary outcome was mortality. Secondary outcomes were hospital and ICU lengths of stay. The impact of pneumonia was determined. Univariate and multivariable Cox's proportional hazards regression analyses informed factors predicting mortality. RESULTS: Burns inhalation injury was diagnosed in 84 of 231 (36%) critically ill burns patients; 20 mild (grade 1), 41 severe (grades 2/3) and 23 unclassified bronchoscopically. Median (IQR) total body surface area burned (TBSA) was 20% (10-40). Mortality was significantly higher in patients with burns inhalation injury vs those without burns inhalation injury (38/84 [45%] vs 35/147 [24%], p < 0.001). Patients with pneumonia had a higher mortality than those without (34/125 [27%] vs 8/71 [11%], p = 0.009). In multivariable analysis, severe burns inhalation injury significantly increased mortality (adjusted HR=2.14, 95%CI: 1.12-4.09, p = 0.022), compared with mild injury (adjusted HR=0.58, 95% CI: 0.18-1.86, p = 0.363). Facial burns (adjusted HR=3.13, 95%CI: 1.69-5.79, p < 0.001), higher TBSA (adjusted HR=1.05, 95%CI: 1.04-1.06, p < 0.001) and older age (adjusted HR=1.04, 95%CI: 1.02-1.07, p < 0.001) also independently predicted mortality, though pneumonia did not. CONCLUSIONS: Severe burns inhalation injury is a significant risk factor for mortality in critically ill burns patients. However, pneumonia did not increase mortality from burns inhalation injury. This work confirms prior implications of bronchoscopically graded burns inhalation injury. Further study is suggested, through registries, into the diagnostic accuracy and reliability of bronchoscopy in burns related lung injury.

Safe and Efficient Practice of Bronchoscopic Sampling from Mechanically Ventilated Patients: A Structured Evaluation of the Ambu Bronchosampler-Ascope 4 Integrated System.

BACKGROUND: Bronchoscopic sampling of bronchoalveolar fluid (BAL) should be safe and effective. Current sampling practice risks loss of sample to the attached negative flow, aerosolisation, or spillage, due to repeated circuit breaks, when replacing sample containers. Such concerns were highlighted during the recent coronavirus pandemic. OBJECTIVES: Evaluation of an alternative integrated sampling solution, with the Ambu Bronchosampler with aScope 4, by an experienced bronchoscopist in ICU. METHODS: An observational study of 20 sequential bronchoscopic diagnostic sampling procedures was performed on mechanically ventilated patients with suspected ventilator-associated pneumonia. Mixed methods assessment was done. The predefined outcome measures were (1) ease of set up, (2) ease of specimen collection, (3) ease of protecting specimen from loss or spillage, and (4) overall workflow. The duration of the procedure and the % volume of sample retrieved were recorded. RESULTS: The mean (±standard deviation [SD]) time for collecting 1 sample was 2.5 ± 0.8 min. The mean (±SD) specimen yield for instilled miniBAL was 54.2 ± 17.9%. Compared with standard sampling, the set-up was much easier in 18 (90%), or easier in 2 (10%) of procedures, reducing the connection steps. It was much more intuitive to use in 14 (70%), more intuitive in 4 (20%), and no more intuitive to use in 2 (10%). The overall set-up and workflow was much easier in 69% of the 13 intraprocedural connections and easier or as easy in the remaining 31% procedures. All procedures where pre connection was established were much easier (7, 100%). The Ambu Bronchosampler remained upright in all procedures with no loss or spillage of sample. Obtaining a sample was much easier in 60%, easier in 10%, no different in 20%, and worse in 10%. The ability to protect a sample from start to finish compared to standard procedures was much easier in 80%, easier in 15%, and no different in 5% of procedures. Overall workflow was much easier in 14 (70%), easier in 4 (20%), and no different in 2 (10%) of procedures. CONCLUSIONS: The Ambu Bronchosampler unit was a reliable, effective, and possibly safer technique for diagnostic sampling in ICU. It may improve safety standards during the coronavirus pandemic. A randomized control trial against the standard sampling technique is warranted.

Performing Bronchoscopy in Times of the COVID-19 Pandemic: Practice Statement from an International Expert Panel.

These recommendations for physicians who perform bronchoscopy will help to protect those patients (un)-affected by the current COVID-19 pandemic, minimize the risk of transmission, and maintain clinical care for all patients.

16S pan-bacterial PCR can accurately identify patients with ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) remains a challenge to intensive care units, with secure diagnosis relying on microbiological cultures that take up to 72 hours to provide a result. We sought to derive and validate a novel, real-time 16S rRNA gene PCR for rapid exclusion of VAP. Bronchoalveolar lavage (BAL) was obtained from two independent cohorts of patients with suspected VAP. Patients were recruited in a 2-centre derivation cohort and a 12-centre confirmation cohort. Confirmed VAP was defined as growth of >104 colony forming units/ml on semiquantitative culture and compared with a 16S PCR assay. Samples were tested from 67 patients in the derivation cohort, 10 (15%) of whom had confirmed VAP. Using cycles to cross threshold (Ct) values as the result of the 16S PCR test, the area under the receiver operating characteristic (ROC) curve (AUROC) was 0.94 (95% CI 0.86 to 1.0, p<0.0001). Samples from 92 patients were available from the confirmation cohort, 26 (28%) of whom had confirmed VAP. The AUROC for Ct in this cohort was 0.89 (95% CI 0.83 to 0.95, p<0.0001). This study has derived and assessed the diagnostic accuracy of a novel application for 16S PCR. This suggests that 16S PCR in BAL could be used as a rapid test in suspected VAP and may allow better stewardship of antibiotics. TRIAL REGISTRATION NUMBER: VAPRAPID trial ref NCT01972425.

Effectiveness of biomarker-based exclusion of ventilator-acquired pneumonia to reduce antibiotic use (VAPrapid-2): study protocol for a randomised controlled trial.

BACKGROUND: Ventilator-acquired pneumonia (VAP) is a common reason for antimicrobial therapy in the intensive care unit (ICU). Biomarker-based diagnostics could improve antimicrobial stewardship through rapid exclusion of VAP. Bronchoalveloar lavage (BAL) fluid biomarkers have previously been shown to allow the exclusion of VAP with high confidence. METHODS/DESIGN: This is a prospective, multi-centre, randomised, controlled trial to determine whether a rapid biomarker-based exclusion of VAP results in fewer antibiotics and improved antimicrobial management. Patients with clinically suspected VAP undergo BAL, and VAP is confirmed by growth of a potential pathogen at [≥] 10(4) colony-forming units per millilitre (CFU/ml). Patients are randomised 1:1, to either a 'biomarker-guided recommendation on antibiotics' in which BAL fluid is tested for IL-1ß and IL-8 in addition to routine microbiology testing, or to 'routine use of antibiotics' in which BAL undergoes routine microbiology testing only. Clinical teams are blinded to intervention until 6 hours after randomisation, when biomarker results are reported to the clinician. The primary outcome is a change in the frequency distribution of antibiotic-free days (AFD) in the 7 days following BAL. Secondary outcome measures include antibiotic use at 14 and 28 days; ventilator-free days; 28-day mortality and ICU mortality; sequential organ failure assessment (SOFA) at days 3, 7 and 14; duration of stay in critical care and the hospital; antibiotic-associated infections; and antibiotic-resistant pathogen cultures up to hospital discharge, death or 56 days. A healthcare-resource-utilisation analysis will be calculated from the duration of critical care and hospital stay. In addition, safety data will be collected with respect to performing BAL. A sample size of 210 will be required to detect a clinically significant shift in the distribution of AFD towards more patients having fewer antibiotics and therefore more AFD. DISCUSSION: This trial will test whether a rapid biomarker-based exclusion of VAP results in rapid discontinuation of antibiotics and therefore improves antibiotic management in patients with suspected VAP. TRIAL REGISTRATION: ISRCTN65937227 . Registered on 22 August 2013. ClinicalTrials.gov, NCT01972425 . Registered on 24 October 2013.

Endobronchial coils for severe emphysema are effective up to 12 months following treatment: medium term and cross-over results from a randomised controlled trial.

BACKGROUND: There is a clinical need for therapeutic options to reduce hyperinflation associated with severe emphysema. Endobronchial Coils (coils) are nitinol devices implanted bronchoscopically under fluoroscopic guidance to re-tension the lung. We report the medium term effectiveness and safety of coils in a study of patients with emphysema. METHODS: Forty five subjects with severe airflow obstruction and hyperinflation received bilateral sequential treatment with coils (30 day interval between treatments) as part of a randomised controlled trial with a primary endpoint 90 days after the final treatment (Clinicaltrials.gov NCT01334307). Further assessments were made at 180 and 360 days and in this study the primary outcome was the effect of coil treatment on the St. George's Respiratory Questionnaire (SGRQ) 360 days following treatment. RESULTS: At 360 days following treatment, there was an improvement in the SGRQ score of -6.1±14.0 points (p = 0.01) compared to baseline. Improvements in secondary outcomes were seen with increases in forced expiratory volume in the first second of 8.9 ±22.2% (p = 0.002) and 6-minute walking distance of 34.1±52.4m (p = 0.003). The safety profile was acceptable out to 360 days post-treatment. CONCLUSIONS: Statistically and clinically meaningful benefits in quality of life, exercise capacity and pulmonary function in patients treated with coils are sustained twelve months after treatment. TRIAL REGISTRATION INFORMATION: Clinicaltrials.gov NCT01334307.

A comparative study of bronchoscopic microsample probe versus bronchoalveolar lavage in patients with burns-related inhalational injury, acute lung injury and chronic stable lung disease.

BACKGROUND AND OBJECTIVES: The bronchoscopic microsample (BMS) probe allows direct epithelial lining fluid (ELF) level measurement without saline lavage. We investigated whether cytokine levels in ELF from a BMS differed from those obtained by bronchoalveolar lavage (BAL) in stable and acute lung disease. METHODS: In a single-centre, prospective observational cohort study of 45 patients, a sequential BMS probe procedure and BAL were performed on patients with stable chronic obstructive lung disease, interstitial lung disease, acute lung injury (ALI), burns-related inhalational injury or controls. ELF samples were assayed for IL-1ß, IL-6, IL-8, TNF-α and G-CSF. RESULTS: Both bronchoscopic microsampling and BAL showed significantly higher cytokine levels in the ELF from patients with ALI and burns-related inhalational injury than from those with chronic stable lung disease. The BMS method detected cytokine levels approximately 20- to 80-fold higher than the corresponding BAL (uncorrected for dilution). The ratio of BMS and BAL cytokine levels was as follows: the ratio for IL-1ß [mean 55, 95% confidence interval (CI) 34-88] was higher than that for IL-6 (mean 16, 95% CI 10-23, p = 0.015) and IL-8 (mean 13, 95% CI -5 to 36, p = 0.03). The ratio for G-CSF (mean 43, 95% CI 24-75) was higher than that for IL-6 (mean 16, 95% CI 10-23, p = 0.008). CONCLUSIONS: The BMS probe safely collects ELF with higher equivalent inflammatory cytokine concentrations than via BAL from patients with both acute and chronic lung disease and can be an alternative to saline BAL. Variations in cytokine concentrations between BMS and BAL and sampling-site differences warrant further study.

A biomarker panel (Bioscore) incorporating monocytic surface and soluble TREM-1 has high discriminative value for ventilator-associated pneumonia: a prospective observational study.

INTRODUCTION: Ventilator-associated pneumonia (VAP) increases mortality in critical illness. However, clinical diagnostic uncertainty persists. We hypothesised that measuring cell-surface and soluble inflammatory markers, incorporating Triggering Receptor Expressed by Myeloid cells (TREM)-1, would improve diagnostic accuracy. METHODS: A single centre prospective observational study, set in a University Hospital medical-surgical intensive Care unit, recruited 91 patients into 3 groups: 27 patients with VAP, 33 ventilated controls without evidence of pulmonary sepsis (non-VAP), and 31 non-ventilated controls (NVC), without clinical infection, attending for bronchoscopy. Paired samples of Bronchiolo-alveolar lavage fluid (BALF) and blood from each subject were analysed for putative biomarkers of infection: Cellular (TREM-1, CD11b and CD62L) and soluble (IL-1ß, IL-6, IL-8, sTREM-1, Procalcitonin). Expression of cellular markers on monocytes and neutrophils were measured by flow cytometry. Soluble inflammatory markers were determined by ELISA. A biomarker panel ('Bioscore'), was constructed, tested and validated, using Fisher's discriminant function analysis, to assess its value in distinguishing VAP from non VAP. RESULTS: The expression of TREM-1 on monocytes (mTREM-1) and neutrophils (nTREM-1) and concentrations of IL-1ß, IL-8, and sTREM-1 in BALF were significantly higher in VAP compared with non-VAP and NVC (p<0.001). The BALF/blood mTREM-1 was significantly higher in VAP patients compared to non-VAP and NVC (0.8 v 0.4 v 0.3 p<0.001). A seven marker Bioscore (BALF/blood ratio mTREM-1 and mCD11b, BALF sTREM-1, IL-8 and IL-1ß, and serum CRP and IL-6) correctly identified 88.9% of VAP cases and 100% of non-VAP cases. CONCLUSION: A 7-marker bioscore, incorporating cellular and soluble TREM-1, accurately discriminates VAP from non-pulmonary infection.

Bronchoscopic intrabullous autologous blood instillation: a novel approach for the treatment of giant bullae.

The current standard therapy for patients with giant bullae is surgical bullectomy; however, high operative risk and comorbidities preclude surgical procedures in many patients. Autologous blood instilled directly into bullae can induce an inflammatory reaction, leading to scarring, fibrosis, and ultimately volume loss. We have treated 5 patients with this minimally invasive approach as day-case procedures using moderate sedation. Three of the 5 patients had shrinkage of the bullae, leading to large and clinically meaningful improvements in lung function, exercise capacity, and quality of life 3 months after treatment.

Endobronchial coils for the treatment of severe emphysema with hyperinflation (RESET): a randomised controlled trial.

BACKGROUND: Few treatment options exist for patients with severe emphysema. We assessed the clinical benefits and safety of lung volume reduction coils (LVRCs) for the treatment of patients with severe emphysema with hyperinflation. METHODS: In a randomised study, we recruited patients with severe emphysema (aged ≥35 years) from three centres in the UK. Using a computer-generated randomisation sequence, we randomly allocated patients in a one-to-one ratio (block sizes of four and stratified by centre) to either LVRC treatment (treatment group) or best medical care (usual care group). The primary endpoint was the difference in response in the St George's Respiratory Questionnaire (SGRQ) between treatment and usual care groups at 90 days after final treatment (by intention-to-treat analysis). The trial is registered with ClinicalTrials.gov, number NCT01334307. FINDINGS: Between Jan 27, 2010, to Oct 25, 2011, we recruited and randomly allocated 47 patients: 23 to treatment and 24 to usual care (23 patients in each group were included in the intention-to-treat analysis). SGRQ response at 90 days after final treatment was greater in the treatment group than it was in the usual care group (between-group difference in change from baseline -8·36 points [95% CI -16·24 to -0·47]; p=0·04). We detected no between-group difference in serious adverse events. INTERPRETATION: Our findings suggest that treatment with endobronchial coils can improve quality of life for patients with severe emphysema and hyperinflation. FUNDING: PneumRx.

The role of transbronchial fine needle aspiration in an integrated care pathway for the assessment of patients with suspected lung cancer.

Transbronchial fine needle aspiration (TBNA) is a simple technique for sampling mediastinal lymph nodes and may provide additional information in patients with suspected lung cancer. However, the technique is still under-utilized, and the objective of this study was to evaluate the value of TBNA as part of an integrated pathway for the assessment of patients with suspected lung cancer. All patients referred to the lung cancer services of our institutions were prospectively evaluated. TBNA was performed in all patients with evidence of mediastinal lymphadenopathy. TBNA of one or more lymph node sites were performed in 129 of these patients. TBNA was the sole diagnostic modality in 23% of patients and provided positive staging information for 49% of patients, with adequate sampling in 71% of patients. Among patients with mediastinal adenopathy, the number of patients who required a TBNA performed to diagnose one patient with malignancy in patients suspected with lung cancer (number needed to diagnose) was 1.47 (95% confidence interval, 1.47-1.76). No complications were observed in patients who underwent TBNA. TBNA improves the diagnostic yield and staging of patients with lung cancer. Moreover, it is a simple, low-cost, and safe test, which should be incorporated into the diagnostic pathway of patients with suspected lung cancer.