Benefit-to-risk balance of bronchoalveolar lavage in the critically ill. A prospective, multicenter cohort study

Cytomegalovirus reactivation in the lower respiratory tract as an independent risk factor for mortality in critically Ill patients

BACKGROUND

The clinical significance of cytomegalovirus reactivation in the lower respiratory tract (LRT) of critically ill patients remains unclear. We aimed to investigate the association between cytomegalovirus reactivation detected in LRT and intensive care unit (ICU) prognosis.

METHODS

This study included critically ill patients admitted to a medical ICU at a tertiary referral center in South Korea between January 2021 and June 2023. Cytomegalovirus load in LRT samples collected via bronchoscopy was measured within 7 days of admission. Detection of cytomegalovirus DNA in LRT was defined as reactivation. Associations between cytomegalovirus reactivation and ICU, in-hospital, 30-day, and 90-day mortality were assessed using multivariable Fine-Gray model adjusted for major clinical factors.

RESULTS

Of the 322 patients (median age 68 years, 66.8% male), 145 (45%) had cytomegalovirus reactivation in the LRT. Cytomegalovirus reactivation was independently associated with increased ICU (adjusted subdistribution hazard ratio [aSHR], 2.28; 95% confidence interval [CI], 1.46-3.56), in-hospital (aSHR, 2.00; 95% CI, 1.44-2.78), 30-day (aSHR, 2.11; 95% CI, 1.42-3.13), and 90-day mortality (aSHR, 2.05; 95% CI, 1.45-2.88). Anti-cytomegalovirus therapy was significantly associated with reduced ICU mortality in patients with radiologic findings suggestive of cytomegalovirus pneumonia (P for interaction = 0.001), but was linked to increased mortality in patients with positive bacterial cultures (P for interaction = 0.002).

CONCLUSION

Cytomegalovirus reactivation in the LRT is associated with poor outcomes in critically ill patients. Anti-cytomegalovirus therapy was not associated with overall survival outcomes; however, the subgroup with radiologic findings of cytomegalovirus pneumonia suggested benefits, while the subgroup with bacterial co-infections suggested harmful effects. Randomized controlled trials are needed.

A comprehensive evaluation of murine and human ex vivo cultured alveolar macrophages

Background

Alveolar macrophages (AMs) serve as the frontline defence in the lungs; however, comprehensive cell culture models for their study remain limited. Freshly isolated AMs are hindered by restricted quantities (mice) or challenges in accessing donors (humans). Recently, murine fetal liver-derived macrophages cultured with granulocyte-macrophages colony-stimulating factor were proposed as AMs-like macrophage (called MPI). Furthermore, recent technical progress improved the culture and expansion of primary murine AMs.

Methods

We examined three distinct in vitro models of alveolar macrophages: MPI, long-term culture-expanded AMs from mice (mAM) and cultured from human (hAM), aiming to compare and elucidate their respective advantages.

Results

We observed that: 1) isolated AMs from mice and humans can be cultured for several days (human) or months (mice) with minor loss of AM-specific surface markers expression over time; 2) MPI is a self-replicative macrophage model that is easy to culture but lacks the typical AM surface expression marker (i.e. SiglecF) and presents a constitutive pro-inflammatory phenotype; 3) responses to Toll-like receptor (TLR) agonists are consistent between MPI, mAM and hAM models but differences in magnitude should be considered; 4) phagocytic activity of MPI, mAM and hAM were similar; 5) major differences were observed between murine and human AMs regarding programmed cell death, especially for MPI; and 6) ecological and ethical consequences of these AM models are different and sometimes opposed and should be carefully assessed.

Conclusion

Our study provides a comprehensive comparison of ex vivo murine and human AM models and gives insight into the translational value of these different AM models.

Towards a holistic approach to pulmonary infections. Insights from the Sixth Annual Meeting of Spanish Experts 2024

Pneumonia is the leading cause of death from infection in the developed world. In recent years, researchers and healthcare professionals have worked extensively to reduce this burden. Prevention is better than cure, and significant advances have been made in areas such as vaccination and the prevention of nosocomial pneumonia in intensive care units. Comprehensive surveillance programmes and new diagnostic methods have been developed to assess trends in this disease and to identify the infectious agents involved. Clinical presentation can be challenging in elderly patients or those with certain comorbidities, prompting new studies in these populations to address these issues. Correct and early management of severe community-acquired pneumonia represents a major opportunity to reduce its associated mortality. Although fungal pathogens are an uncommon cause of lung infection, they are associated with high morbidity and mortality, highlighting the need for new approaches. Finally, new drugs are available for the treatment of pneumonia, and a thorough understanding of them is key to ensuring their correct use, particularly to combat multi-resistance. To provide an update on these points, a multidisciplinary team of Spanish experts convened at the Sixth Annual Meeting of Pneumonia Day, under the scientific sponsorship of GEIPC-SEIMC. This paper reflects the information shared at this meeting, offering the latest insights on these topics and supporting a holistic approach to pneumonia management.

Precision Medicine in Acute Respiratory Distress Syndrome: Progress, Challenges, and the Road ahead

Several novel high-dimensional biologic measurements are increasingly being applied to biomedical sciences. Acute respiratory distress syndrome (ARDS) is a theoretically fertile ground for such approaches. Not only are these biologic and analytic tools available to better understand ARDS but also arguably, simpler approaches such as respiratory physiology has been vastly underutilized as a means of delivering precision-based care in the field. Here we review the progress made in ARDS toward discovering biologically homogeneous phenotypes, treatment responsive subgroups, the challenges to implement these discoveries at the bedside, and the road ahead that will enable precision medicine in ARDS.

Combining high-flow nasal cannula oxygen therapy with repeated toilet bronchoscopies for respiratory failure due to excessive infected airway secretions: a case report and series from a non-intensive hospital ward

Fiberoptic bronchoscopy (FBO) has diagnostic or therapeutic purposes but can cause respiratory deterioration, particularly in patients with pre-existing acute respiratory failure (ARF). Non-invasive ventilation (NIV) and high-flow nasal cannula oxygen therapy (HFNC) are used as respiratory support for ARF as well as to prevent significant oxygen deterioration during FBO. The combined use of NIV and early therapeutic FBO to clear retained abundant infected secretions from the airways may be an alternative to intubation and invasive mechanical ventilation (IMV), but no data exist on the combined use of FBO and HFNC. A 78-year-old male patient with ARF secondary to chronic obstructive pulmonary disease (COPD) exacerbation and pneumonia was admitted to our non-intensive geriatric ward. After an initial improvement, his respiratory conditions worsened. While continuing HFNC, he underwent a series of eight FBOs over 9 days, each performed in response to significant decreases in peripheral oxygen saturation (SpO2). The goal was to remove copious and occlusive infected secretions from the airways, with each procedure resulting in good SpO2 recovery. After etiological targeted antibiotic therapy based on bronchial aspirate, the patient improved and was discharged. Next, six consecutive similar ARF patients were treated using the same strategy of combining HFNC with repeated toilet FBO performed within the ward to clear secretions. All patients showed improvement and were discharged. The combination of HFNC and repeated toilet FBO could be a safe and effective intervention in non-intensive wards to prevent intubation and IMV in frail and elderly patients with ARF secondary to copious and occlusive infected secretions in the airways.

Severe Community-Acquired Pneumonia in Immunocompromised Patients

Due to higher survival rates with good quality of life, related to new treatments in the fields of oncology, hematology, and transplantation, the number of immunocompromised patients is increasing. But these patients are at high risk of intensive care unit admission because of numerous complications. Acute respiratory failure due to severe community-acquired pneumonia is one of the leading causes of admission. In this setting, the need for invasive mechanical ventilation is up to 60%, associated with a high hospital mortality rate of around 40 to 50%. A wide range of pathogens according to the reason of immunosuppression is associated with severe pneumonia in those patients: documented bacterial pneumonia represents a third of cases, viral and fungal pneumonia both account for up to 15% of cases. For patients with an undetermined etiology despite comprehensive diagnostic workup, the hospital mortality rate is very high. Thus, a standardized diagnosis strategy should be defined to increase the diagnosis rate and prescribe the appropriate treatment. This review focuses on the benefit-to-risk ratio of invasive or noninvasive strategies, in the era of omics, for the management of critically ill immunocompromised patients with severe pneumonia in terms of diagnosis and oxygenation.

Efficacy and safety of remimazolam in bronchoscopic sedation: A meta-analysis

BACKGROUND

Remimazolam is a new benzodiazepine used for procedural sedation and general anesthesia. Several studies have used remimazolam for bendable bronchoscopy.

AIM

To assess the safety and efficacy of remimazolam for sedation in patients undergoing bendable bronchoscopy by performing a meta-analysis of randomized controlled trials (RCTs).

METHODS

We searched the EMBASE, PubMed, Cochrane Library, and Web of Science databases for RCTs on bendable bronchoscopic procedural sedation with remimazolam vs conventional sedatives (CS).

RESULTS

Five studies with 1080 cases were included. Remimazolam had the same sedation success rate compared with CS [relative risk (RR): 1.35, 95%CI: 0.60-3.05, P = 0.474, I2 = 99.6%]. However, remimazolam was associated with a lower incidence of hypotension (RR: 0.61; 95%CI: 0.40-0.95, P = 0.027; I2 = 65.1%) and a lower incidence of respiratory depression (RR: 0.50, 95%CI: 0.33-0.77, P = 0.002, I2 = 42.3%). A subgroup analysis showed a higher success rate of sedation with remimazolam than midazolam (RR: 2.45, 95%CI: 1.76-3.42, P < 0.001). Compared with propofol, the incidence of hypotension (RR: 0.45, 95%CI: 0.32-0.64, P < 0.001, I2 = 0.0%), respiratory depression (RR: 0.48, 95%CI: 0.30-0.76, P = 0.002, I2 = 78.4%), hypoxemia (RR: 0.36, 95%CI: 0.15-0.87, P = 0.023), and injection pain (RR: 0.04, 95%CI: 0.01-0.28, P = 0.001) were lower.

CONCLUSION

Remimazolam is safe and effective during bronchoscopy. The sedation success rate was similar to that in the CS group. However, remimazolam has a higher safety profile, with fewer inhibitory effects on respiration and circulation.

Research Bronchoscopies in Critically Ill Research Participants: An Official American Thoracic Society Workshop Report

Bronchoscopy for research purposes is a valuable tool to understand lung-specific biology in human participants. Despite published reports and active research protocols using this procedure in critically ill patients, no recent document encapsulates the important safety considerations and downstream applications of this procedure in this setting. The objectives were to identify safe practices for patient selection and protection of hospital staff, provide recommendations for sample procurement to standardize studies, and give guidance on sample preparation for novel research technologies. Seventeen international experts in the management of critically ill patients, bronchoscopy in clinical and research settings, and experience in patient-oriented clinical or translational research convened for a workshop. Review of relevant literature, expert presentations, and discussion generated the findings presented herein. The committee concludes that research bronchoscopy with bronchoalveolar lavage in critically ill patients on mechanical ventilation is valuable and safe in appropriately selected patients. This report includes recommendations on standardization of this procedure and prioritizes the reporting of sample management to produce more reproducible results between laboratories. This document serves as a resource to the community of researchers who endeavor to include bronchoscopy as part of their research protocols and highlights key considerations for the inclusion and safety of research participants.

Timing of bronchoscopy and application of scoring tools in children with severe pneumonia

BACKGROUND

There is still a lack of effective scoring criteria for assessing the severity of pulmonary infection associated with changes in the endobronchial lining of the bronchus in children. This study aimed to ascertain the timing and value of endoscopic scoring of fibreoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) in children with severe pneumonia.

METHOD

The clinical data of 229 children with severe pneumonia treated with BAL in the Pediatric Intensive Care Unit of the First Affiliated Hospital of Xinxiang Medical University between November 2018 and December 2021 were collected. According to the severity of the disease, patients were divided into an invasive ventilation group and a non-invasive ventilation group, as well as an early BAL group (receiving BAL within 1 day of admission) and a late BAL group (receiving BAL 2 days after admission). A Student's t-test, Chi-square test, receiver operating characteristic (ROC) curve and survival curve were used to analyse the bronchitis score, aetiology of BAL fluid and survival data.

RESULTS

The scores of endoscopic mucosal oedema, erythema and pallor and the total score in the invasive ventilation group were higher than those in the non-invasive ventilation group (P < 0.05), and they were consistent with the Sequential Organ Failure Assessment (SOFA) scores. The secretion colour score was lower in the early BAL group than in the late BAL group (P < 0.05). On the bronchitis scores, which were evaluated using a ROC curve, the difference in the mucosal erythema, pallor, oedema and total score of the invasive and non-invasive groups was statistically significant (P < 0.05), which was consistent with the area under the ROC of the SOFA scores. Acute Physiology and Chronic Health Assessment II and SOFA scores after FOB were lower than those before treatment (P < 0.05). In terms of ICU hospitalisation days and total hospitalisation days, the time of the early FOB patients was shorter than that of the late FOB patients (P < 0.05). A total of 22 patients (9.61%) died. The Kaplan-Meier analysis and log-rank test showed that the survival rate of the non-invasive ventilation group was higher than that of the invasive ventilation group (P < 0.05).

CONCLUSION

This study found that FOB combined with BAL is an important method for the diagnosis and treatment of severe pneumonia. Early BAL can reduce hospitalisation and ICU time; however, it cannot improve the survival rate. The endoscopic score has a certain role to play in assessing the severity of pulmonary inflammation, but studies with a large sample are still needed to confirm this.

Ventilator-Associated Pneumonia in Immunosuppressed Patients

Immunocompromised patients-including patients with cancer, hematological malignancies, solid organ transplants and individuals receiving immunosuppressive therapies for autoimmune diseases-account for an increasing proportion of critically-ill patients. While their prognosis has improved markedly in the last decades, they remain at increased risk of healthcare- and intensive care unit (ICU)-acquired infections. The most frequent of these are ventilator-associated lower respiratory tract infections (VA-LTRI), which include ventilator-associated pneumonia (VAP) and tracheobronchitis (VAT). Recent studies have shed light on some of the specific features of VAP and VAT in immunocompromised patients, which is the subject of this narrative review. Contrary to previous belief, the incidence of VAP and VAT might actually be lower in immunocompromised than non-immunocompromised patients. Further, the relationship between immunosuppression and the incidence of VAP and VAT related to multidrug-resistant (MDR) bacteria has also been challenged recently. Etiological diagnosis is essential to select the most appropriate treatment, and the role of invasive sampling, specifically bronchoscopy with bronchoalveolar lavage, as well as new molecular syndromic diagnostic tools will be discussed. While bacteria-especially gram negative bacteria-are the most commonly isolated pathogens in VAP and VAT, several opportunistic pathogens are a special concern among immunocompromised patients, and must be included in the diagnostic workup. Finally, the impact of immunosuppression on VAP and VAT outcomes will be examined in view of recent papers using improved statistical methodologies and treatment options-more specifically empirical antibiotic regimens-will be discussed in light of recent findings on the epidemiology of MDR bacteria in this population.

Temporal Trends and Variation in Bronchoscopy Use for Acute Respiratory Failure in the United States

BACKGROUND

National data on bronchoscopy for the evaluation of acute respiratory failure are lacking, and the limited available data suggest wide variation in use.

RESEARCH QUESTION

How commonly is bronchoscopy performed among hospitalizations with acute respiratory failure? How has use changed over time and across hospitals?

STUDY DESIGN AND METHODS

This was an observational cohort study of adult hospitalizations (2012-2018) treated with invasive mechanical ventilation (IMV) using the National Inpatient Sample, which represents 97% of all hospitalizations in the United States. We measured the proportion of hospitalizations treated with IMV who underwent bronchoscopy and assessed trends in bronchoscopy use over time. Multilevel linear regression models were used to quantify hospital-level variation, adjusting for differences in patient and hospital characteristics.

RESULTS

We identified 6,101,070 IMV-treated hospitalizations (2012-2018), of whom 609,405 underwent bronchoscopy; among hospitalizations receiving bronchoscopy, mean age was 61 years, 41.8% were women, and in-hospital mortality was 30.8%. The percentage of IMV-treated hospitalizations receiving bronchoscopy increased from 9.5% (95% CI, 9.1%-9.9%) in 2012 to 10.8% (95% CI, 10.4%-11.2%) in 2018 (P < .001 for difference). In 2018, bronchoscopy use varied from 0% to 57.1% among 1,787 hospitals, and in multilevel models adjusted for patient and hospital characteristics, 16.0% of the variation was explained at the hospital level. The median OR was 2.13 (95% CI, 2.05-2.21), indicating 113% increased odds of receiving bronchoscopy if moving from a lower-use to a higher-use hospital.

INTERPRETATION

Bronchoscopy use among hospitalizations treated with IMV has increased over time. The large variation in use of bronchoscopy across hospitals suggests potentially unwarranted practice variation and need for further studies to clarify which patients benefit from bronchoscopy.

Efficacy and safety of ciprofol-remifentanil versus propofol-remifentanil during fiberoptic bronchoscopy: A prospective, randomized, double-blind, non-inferiority trial

Objective: Ciprofol is a novel 2,6-disubstituted phenol derivative that has improved pharmacokinetic and pharmacodynamic properties compared with propofol. This study was conducted to compare the efficacy and safety of ciprofol-remifentanil versus propofol-remifentanil for patients undergoing fiberoptic bronchoscopy. Methods: Overall, 92 patients undergoing fiberoptic bronchoscopy were included in this prospective, randomized, double-blind, non-inferiority trial and were equally divided into two groups (n = 46 each). Fentanyl (50 μg) was given 2 min before the intravenous infusion of 0.3 mg/kg of ciprofol or 1.2 mg/kg of propofol over a time period of 30 s. During anesthesia maintenance, 0.05-0.2 μg/kg/min of remifentanil combined with one-third to one-fourth of the initial dose of ciprofol or propofol was repeated at 2-min intervals, as required, to maintain a Modified Observer's Assessment of Alertness and Sedation (MOAA/S) scale score <3. The primary outcome was the successful rate of fiberoptic bronchoscopy. Secondary outcomes included demographic characteristics, time metrics, hemodynamics, coughing severity, intubating conditions, lowest oxygen saturation, utilization of study drug doses, number of remedies (lidocaine and vasoactive drugs) used, satisfaction scores of both patients and the endoscopist, occurrence of intraoperative awareness, patients' willing to repeat fiberoptic bronchoscopy, and occurrence and severity of adverse events. Results: The successful completion rate of fiberoptic bronchoscopy was 91.30% (42 of 46; 95% confidence interval [CI]: 82.80%-99.80%) in the ciprofol-remifentanil group and 89.13% (41 of 46; 95% CI: 79.80%-98.50%) in the propofol-remifentanil group. Though the clinically acceptable intubating condition was improved in the ciprofol-remifentanil group, this difference has no clinical statistical difference (p > 0.05). No significant differences were noted between the two groups with respect to time metrics, consumption of fentanyl and remifentanil, or number of remedies (lidocaine and vasoactive drugs). Patients' willingness to repeat fiberoptic bronchoscopy and the satisfaction of both patients and endoscopist were significantly higher in the ciprofol-remifentanil than in the propofol-remifentanil group (p < 0.05). Compared with patients in the propofol-remifentanil group, patients in the ciprofol-remifentanil group had more stable hemodynamics. The lowest oxygen saturation was significantly higher in the ciprofol-remifentanil than in the propofol-remifentanil group (p < 0.05). The numbers of patients who experienced pain on injection in the ciprofol-remifentanil group was significantly lower than the number in the propofol-remifentanil group (p < 0.01). Severity of coughing, clinically acceptable severity of coughing, incidence of intraoperative awareness, and other adverse events were all similar between the two groups (p > 0.05). Only four patients experienced grade 2 adverse events (severe hypotension in one patient in the ciprofol-remifentanil group and three patients in the propofol-remifentanil group; p > 0.05); they were treated with noradrenaline. Conclusion: Ciprofol-remifentanil was non-inferior to propofol-remifentanil with regard to successful sedation for flexible bronchoscopy, when used with pre-intravenous administration of 50 μg of fentanyl. At the same time, patients' willingness to repeat flexible bronchoscopy and the satisfactions were all significantly improved.

Feasibility and Safety of Transbronchial Lung Cryobiopsy for Diagnosis of Acute Respiratory Failure with Mechanical Ventilation in Intensive Care Unit

BACKGROUND

Acute hypoxemic respiratory failure is common in intensive care units (ICUs). Lung biopsies may be required to make a definitive diagnosis in patients with unknown etiologies. The feasibility of transbronchial lung cryobiopsy is undetermined in patients with respiratory failure in the ICU.

METHODS

Patients who underwent bronchoscopy examinations with transbronchial lung cryobiopsy (TBLC) between July 2018 and December 2019 were retrospectively analyzed through medical chart review. The procedures were performed by well-experienced interventional pulmonologists.

RESULTS

Ten patients underwent bronchoscopy examinations with TBLC in the ICU at Chang Gung Memorial Hospital during the study period. In all patients, the diagnosis was made via pathological analysis. One patient developed pneumothorax and required chest tube placement after the procedure. None of the patients had bleeding requiring blood transfusion, and no deaths were directly related to the procedure.

CONCLUSIONS

TBLC is a feasible technique to obtain lung pathology in patients with acute respiratory diseases of unknown etiologies. While the complication rate may be acceptable, the procedure should be performed by experienced interventional pulmonologists. However, airway blockers and fluoroscopy are highly recommended when used according to the current guideline. We do not encourage TBLC to be performed without having airway blockers available at the bedside.

Anesthesia for interventional pulmonology

PURPOSE OF REVIEW

Anesthesia for pulmonological interventions is a demanding challenge. This article discusses recent innovations and the implications for periinterventional anesthetic management.

RECENT FINDINGS

Interventional pulmonology is a rapidly expanding specialty with very complex diagnostic and therapeutic approaches that include oncological staging, treatment of obstructive and restrictive lung diseases, recanalization of endobronchial obstructions, and retrieval of foreign bodies. With the development of advanced diagnostic and therapeutic interventions, the application is extended to critically ill patients. Current evidence focusing on the anesthetic techniques is presented here.

SUMMARY

The development of new pulmonological methods requires a tailored anesthesiological approach. Their specific impact must be taken into account to ensure patient safety, goal-oriented outcome diagnostics and -quality, successful interventions, and patient comfort.

Should high-flow through nasal cannula be used during bronchoscopy in critically ill patients with hypoxemic acute respiratory failure?

Flexible fiberoptic bronchoscopy (FOB) is an invasive procedure with diagnostic and/or therapeutic purposes commonly used in critically ill patients. FOB may be complicated by desaturation, onset or worsening of the respiratory failure, and hemodynamic instability due to cardio-respiratory alterations occurring during the procedure. Increasing evidences suggest the use of high-flow through nasal cannula (HFNC) over conventional oxygen therapy (COT) in critically ill patients with acute respiratory failure (ARF). Indeed, HFNC has a rationale and possible physiologic advantages, even during FOB. However, to date, evidences in favor of HFNC over COT or continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV) during FOB are still weak. Nonetheless, in critically ill patients with hypoxemic ARF, the choice of the oxygenation strategy during a FOB is challenging. Based on a review of the literature, HFNC may be preferred over COT in patients with mild to moderate hypoxemic ARF, without cardiac failure or hemodynamic instability. On the opposite, in critically ill patients with more severe hypoxemic ARF or in the presence of cardiac failure or hemodynamic instability, CPAP or NIV, applied with specifically designed interfaces, may be preferred over HFNC.

Laryngotracheal aspiration test reduce the false negative rate in patients with suspected SARS-COV-2 pneumonia despite a negative nasopharyngeal swab

BACKGROUND

In the emergency department (ED) definitive diagnosis of SARS-COV-2 pneumonia is challenging as nasopharyngeal swab (NPS) can give false negative results. Strategies to reduce false negative rate of NPS have limitations. Serial NPSs (24-48 h from one another) are time-consuming, sputum can not be collected in the majority of patients, and bronchoalveolar lavage (BAL), the most sensitive test, requires specific expertise. Laryngotracheal aspiration (LTA) is easy to perform and showed a similar accuracy to BAL for diagnosis of other pulmonary diseases, however it was not studied to diagnose SARS-COV-2 pneumonia.

OBJECTIVE

An observational cross-sectional study was performed to evaluate the negative predictive value of LTA in patients with suspected SARS-COV-2 pneumonia despite a negative NPS.

METHODS

In the EDs of two university hospitals, consecutive patients with suspected SARS-COV-2 pneumonia despite a negative NPS underwent LTA performed with a nasotracheal tube connected to a vacuum system. Final diagnosis based on all respiratory specimen tests (NPS, LTA and BAL) and hospital data was established by two reviewers and in case of discordance by a third reviewer.

RESULTS

117 patients were enrolled. LTA was feasible in all patients and no patients experienced adverse events. Fifteen (12.7%) patients were diagnosed with community-acquired SARS-COV-2 pneumonia: 13 LTA positive and only 2 (1.7%) LTA negative. The negative predictive value of NPS and LTA was 87.3% (79.9% - 92.7%) and 98.1% (93.3%99.8%) respectively.

CONCLUSIONS

LTA resulted feasible, safe and reduced false negative rate in patients with suspected SARS-COV-2 pneumonia despite a negative NPS.

Systematic review of studies investigating ventilator associated pneumonia diagnostics in intensive care

BACKGROUND

Ventilator-associated pneumonia (VAP) is an important diagnosis in critical care. VAP research is complicated by the lack of agreed diagnostic criteria and reference standard test criteria. Our aim was to review which reference standard tests are used to evaluate novel index tests for suspected VAP.

METHODS

We conducted a comprehensive search using electronic databases and hand reference checks. The Cochrane Library, MEDLINE, CINHAL, EMBASE, and web of science were searched from 2008 until November 2018. All terms related to VAP diagnostics in the intensive treatment unit were used to conduct the search. We adopted a checklist from the critical appraisal skills programme checklist for diagnostic studies to assess the quality of the included studies.

RESULTS

We identified 2441 records, of which 178 were selected for full-text review. Following methodological examination and quality assessment, 44 studies were included in narrative data synthesis. Thirty-two (72.7%) studies utilised a sole microbiological reference standard; the remaining 12 studies utilised a composite reference standard, nine of which included a mandatory microbiological criterion. Histopathological criteria were optional in four studies but mandatory in none.

CONCLUSIONS

Nearly all reference standards for VAP used in diagnostic test research required some microbiological confirmation of infection, with BAL culture being the most common reference standard used.

Changes in the management and clinical outcomes of critically ill patients without COVID-19 during the pandemic

Objective

To analyze whether changes in medical care due to the application of COVID-19 protocols affected clinical outcomes in patients without COVID-19 during the pandemic.

Methods

This was a retrospective, observational cohort study carried out in a thirty-eight-bed surgical and medical intensive care unit of a high complexity private hospital. Patients with respiratory failure admitted to the intensive care unit during March and April 2020 and the same months in 2019 were selected. We compared interventions and outcomes of patients without COVID-19 during the pandemic with patients admitted in 2019. The main variables analyzed were intensive care unit respiratory management, number of chest tomography scans and bronchoalveolar lavages, intensive care unit complications, and status at hospital discharge.

Results

In 2020, a significant reduction in the use of a high-flow nasal cannula was observed: 14 (42%) in 2019 compared to 1 (3%) in 2020. Additionally, in 2020, a significant increase was observed in the number of patients under mechanical ventilation admitted to the intensive care unit from the emergency department, 23 (69%) compared to 11 (31%) in 2019. Nevertheless, the number of patients with mechanical ventilation after 5 days of admission was similar in both years: 24 (69%) in 2019 and 26 (79%) in 2020.

Conclusion

Intensive care unit protocols based on international recommendations for the COVID-19 pandemic have produced a change in non-COVID-19 patient management. We observed a reduction in the use of a high-flow nasal cannula and an increased number of tracheal intubations in the emergency department. However, no changes in the percentage of intubated patients in the intensive care unit, the number of mechanical ventilation days or the length of stay in intensive care unit.

Cytopathology of bronchoalveolar lavages in COVID___19 pneumonia: A pilot study

BACKGROUND

Bronchoalveolar lavage (BAL) in patients with severe coronavirus disease 2019 (COVID‐19) may provide additional and complementary findings for the management of these patients admitted to intensive care units (ICUs). This study addresses the cytological features of the infection and highlights the more influential inflammatory components. The correlation between pathological variables and clinical data is also analyzed.

METHODS

The authors performed a retrospective analysis of the cytopathological features of BAL in 20 COVID‐19 patients and 20 members of a matched cohort from a critical ICU who had acute respiratory distress syndrome caused by other pulmonary conditions.

RESULTS

A comparison of the controls (n = 20) and the COVID‐19 patients (n = 20) revealed that the latter had a higher neutrophil count (median, 63.8% of the cell count) with lower percentages of macrophages and lymphocytes. An increase in the expression of CD68‐positive, monocytic multinucleated giant cells (MGCs) was reported; megakaryocytes were not detected on CD61 staining. Perls staining showed isolated elements. In situ RNA analysis demonstrated scattered chromogenic signals in type II pneumocytes. An ultrastructural analysis confirmed the presence of intracytoplasmic vacuoles containing rounded structures measuring 140 nm in diameter (putative viral particles). In COVID‐19 patients, the clinicopathological correlation revealed a positive correlation between lactate dehydrogenase values and MGCs (r = 0.54).

CONCLUSIONS

The analysis of BAL samples might be implemented as a routine practice for the evaluation of COVID‐19 patients in ICUs in the appropriate clinical scenario. Additional studies using a larger sample size of patients who developed COVID‐19 during the second wave of the epidemic in the autumn of 2020 are needed to further support our findings.

An analysis of the cytological features of bronchoalveolar lavage samples can provide useful information for the management of coronavirus disease 2019 patients in the intensive care unit.