Venovenous extracorporeal membrane oxygenation for COVID-19 and influenza H1N1 associated acute respiratory distress syndrome: A comparative cohort study in China.

Background: Venovenous extracorporeal membrane oxygenation (VV-ECMO) has been demonstrated to be effective in treating patients with virus-induced acute respiratory distress syndrome (ARDS). However, whether the management of ECMO is different in treating H1N1 influenza and coronavirus disease 2019 (COVID-19)-associated ARDS patients remains unknown. Methods: This is a retrospective cohort study. We included 12 VV-ECMO-supported COVID-19 patients admitted to The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Eighth People's Hospital, and Wuhan Union Hospital West Campus between January 23 and March 31, 2020. We retrospectively included VV-ECMO-supported patients with COVID-19 and H1N1 influenza-associated ARDS. Clinical characteristics, respiratory mechanics including plateau pressure, driving pressure, mechanical power, ventilatory ratio (VR) and lung compliance, and outcomes were compared. Results: Data from 25 patients with COVID-19 (n=12) and H1N1 (n=13) associated ARDS who had received ECMO support were analyzed. COVID-19 patients were older than H1N1 influenza patients (P=0.004). The partial pressure of arterial carbon dioxide (PaCO2) and VR before ECMO initiation were significantly higher in COVID-19 patients than in H1N1 influenza patients (P <0.001 and P=0.004, respectively). COVID-19 patients showed increased plateau and driving pressure compared with H1N1 subjects (P=0.013 and P=0.018, respectively). Patients with COVID-19 remained longer on ECMO support than did H1N1 influenza patients (P=0.015). COVID-19 patients who required ECMO support also had fewer intensive care unit and ventilator-free days than H1N1. Conclusions: Compared with H1N1 influenza patients, COVID-19 patients were older and presented with increased PaCO2 and VR values before ECMO initiation. The differences between ARDS patients with COVID-19 and influenza on VV-ECMO detailed herein could be helpful for obtaining a better understanding of COVID-19 and for better clinical management.

Patients with infectious diseases undergoing mechanical ventilation in the intensive care unit have better prognosis after receiving metagenomic next-generation sequencing assay.

OBJECTIVES: To evaluate the relation between metagenomic next-generation sequencing (mNGS) and the prognosis of patients with infectious diseases undergoing mechanical ventilation in the intensive care unit (ICU). METHODS: This is a single-center observational study, comparing nonrandomly assigned diagnostic approaches. We analyzed the medical records of 228 patients with suspected infectious diseases undergoing mechanical ventilation in the ICU from March 2018 to May 2020. The concordance of pathogen results was also assessed for the results of mNGS, culture, and polymerase chain reaction assays. RESULTS: The 28-day mortality of the patients in the mNGS group was lower after the baseline difference correction (19.23% (20/104) vs 29.03% (36/124) , P = 0.039). Subgroup analysis showed that mNGS assay was associated with improved 28-day mortality of patients who are not immunosuppressed (14.06% vs 29.82%, P = 0.018). Not performing mNGS assay, higher acute physiology and chronic health evaluation II score, and hypertension are independent risk factors for 28-day mortality. The mNGS assay presented an advantage in pathogen positivity (69.8% double-positive and 25.0% mNGS-positive only), and the concordance between these two assays was 79.0%. CONCLUSION: mNGS survey may be associated with a better prognosis by reducing 28-day mortality of patients with infectious diseases on mechanical ventilation in the ICU. This technique presented an advantage in pathogen positivity over traditional methods.

Independent risk factors of hypoxemia in patients after surgery with acute type A aortic dissection.

BACKGROUND: This study aimed to investigate independent risk factors of postoperative hypoxemia in patients with acute type A aortic dissection (ATAAD). METHODS: A single-center retrospective study was conducted with enrolled 75 ATAAD patients following surgery, which were stratified into three groups on the basis of the postoperative PaO2/FiO2 ratio: severe hypoxemia group (PaO2/FiO2 ratio ≤100 mmHg); moderate hypoxemia group (100 mmHg < PaO2/FiO2 ratio ≤200 mmHg); and non-hypoxemia group (PaO2/FiO2 ratio >200 mmHg). The patient's demography, perioperative laboratory results, operative details, clinical outcomes were collected and analyzed. Univariable and multivariable analyses were performed and logistic regression model was established. RESULTS: The incidence of postoperative severe hypoxemia and hypoxemia was 32% and 52%, respectively. Among the three groups, severe hypoxemia group exhibited a high significance of body mass index (BMI) and preoperative white blood cell (WBC) and main distribution of hypertension; meanwhile, Marfan syndrome was mainly distributed in non-hypoxemia group. On intensive care unit (ICU) admission, severe hypoxemia group exhibited a high significance of Acute Physiology and Chronic Health Evaluation (APACHE II) score of postoperative patients, and more patients would present shock. Moreover, severe hypoxemia group patients had a higher incidence of postoperative acute kidney injury (AKI) and usage of renal replacement therapy, longer length of stay (LOS) of ICU, and shorter 28 days ventilator-free days (VFDs). CONCLUSIONS: The incidence of postoperative hypoxemia was high in ATAAD patients owing to comprehensive high-risk factors. Besides, postoperative complications negatively impacted their clinical outcomes.

Noninvasive ventilation support during fiberoptic bronchoscopy-guided nasotracheal intubation effectively prevents severe hypoxemia.

PURPOSE: This study investigated the feasibility and efficacy of continuous noninvasive ventilation (NIV) support with 100% oxygen using a specially designed face mask, for reducing desaturation during fiberoptic bronchoscopy (FOB)-guided intubation in critically ill patients with respiratory failure. MATERIALS AND METHODS: This was a single-center prospective randomized study. All patients undergoing FOB-guided nasal tracheal intubation were randomized to bag-valve-mask ventilation or NIV for preoxygenation followed by intubation. The NIV group were intubated through a sealed hole in a specially designed face mask during continuous NIV support with 100% oxygen. Control patients were intubated with removal of the mask and no ventilatory support. RESULTS: We enrolled 106 patients, including 53 in each group. Pulse oxygen saturation (SpO2) after preoxygenation (99% (96%-100%) vs. 96% (90%-99%), p = .001) and minimum SpO2 during intubation (95% (87%-100%) vs. 83% (74%-91%), p < .01) were both significantly higher in the NIV compared with the control group. Severe hypoxemic events (SpO2 < 80%) occurred less frequently in the NIV group than in controls (7.4% vs. 37.7%, respectively; p < .01). CONCLUSIONS: Continuous NIV support during FOB-guided nasal intubation can prevent severe desaturation during intubation in critically ill patients with respiratory failure. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02462668. Registered on 25 May 2015, https://www.clinicaltrials.gov/ct2/results?term=NCT02462668.

Prone position ventilation support for acute exacerbation of interstitial lung disease?

INTRODUCTION: Prone position ventilation (PPV) has been shown to improve oxygenation and decrease pulmonary vascular resistance and mortality in patients with severe acute respiratory distress syndrome (ARDS). Whether these benefits of PPV occur similarly in acute exacerbations of interstitial lung disease (ILD) is not clear. We retrospectively explored the use of PPV in acute exacerbation with ILD versus those with severe acute respiratory distress syndrome (severe ARDS). METHODS: Retrospective study of the application of PPV in 17 patients with acute exacerbations of ILD and in 19 patients with severe ARDS. Pre- and post-PPV hemodynamic parameters, respiratory mechanics, prognostic indicators, complications and mortality rates at 28, 60 and 90 days were compared. RESULTS: There was no difference in baseline characteristics between the two groups except for higher driving pressure and more diastolic dysfunction in ILD group than severe ARDS group Compared with pre-PPV, cardiac index and driving pressure remained unchanged post-PPV in both groups. PPV increased PaO2 /FiO2 [118.7 (92.0, 147.8) pre-PPV vs 132.0 (93.5, 172.0) post-PPV; P < 0.05] and central venous oxygenation in patients with ILD. In patients with severe ARDS, PPV significantly increased PaO2 /FiO2 [109.23 (89,135) pre- PPV vs 126.13 (100.93, 170) post-PPV; P < 0.05] and intrathorax blood volume index. However, mortality rates at 28, 60 and 90 days remained high in both groups (76.4%, 88.2% and 88.2% vs 36.8%, 57.9% and 57.9% in ILD and severe ARDS, respectively; P < 0.05). CONCLUSION: Our findings suggest that PPV may improve oxygenation and partially improve hemodynamic parameters during acute exacerbations of ILD.

[Effect of prone position ventilation on respiratory mechanics and prognosis in patients with acute respiratory distress syndrome concurrent with interstitial lung disease].

OBJECTIVE: To explore the effect of prone position ventilation (PPV) on respiratory mechanics and prognosis in patients with acute respiratory distress syndrome (ARDS) concurrent with interstitial lung disease (ILD). METHODS: The data of 36 severe ARDS patients admitted to Department of Critical Care Medicine of the First Affiliated Hospital of Guangzhou Medical University from February 2013 to January 2015, were retrospectively analyzed. They were then divided into two groups according to the presence of ILD or not. The changes in respiratory mechanics and oxygenation indexes were compared before and after PPV treatment in all the patients. Kaplan-Meier method was applied to draw the 60-day survival curves of both groups. RESULTS: There were 17 cases with ILD among these 36 severe ARDS patients. (1) No significant difference was found in baseline data between ILD group and non-ILD group. (2) Respiratory mechanics and oxygenation pre-PPV and post-PPV: compared with pre-PPV, oxygenation index (PaO2/FiO2, mmHg, 1 mmHg = 0.133 kPa) post-PPV was significantly increased in both groups [ILD group : 132.0 (93.5, 172.0) vs. 118.7 (92.0, 147.8); non-ILD group: 126.1 (100.9, 170.0) vs. 109.2 (89.0, 135.0), both P < 0.05]. Compared with pre-PPV, positive end-expiratory pressure (PEEP, cmH2O, 1 cmH2O = 0.098kPa) post-PPV was significantly higher in ILD group [10.0 (10.0, 12.0) vs. 10.0 (9.2, 12.0), P < 0.05], and respiratory rate (RR, times/min) was significantly lower in non-ILD group [24.5 (22.0, 27.0) vs. 25.5 (22.8, 28.0), P < 0.05]. The compliance of the respiratory system (Crs, mL/cmH2O) post-PPV in non-ILD group was significantly lower than that of the ILD group [19.7 (16.1, 28.6) vs. 23.0 (19.0, 29.7), P < 0.05]. (3) Respiratory mechanics and oxygenation pre-PPV and post-PPV in total: after all the PPV therapy, PaO2/FiO2 (mmHg) was significantly increased in non-ILD group [135.0 (86.0, 200.0) vs. 97.4 (69.2, 127.5), P < 0.05], PaO2/FiO2 after all the PPV therapy in non-ILD group was also higher than that in ILD group [135.0 (86.0, 200.0) vs. 78.7 (59.3, 114.9), P < 0.05]. No significant difference in Crs (mL/cmH2O) before PPV treatment was found between non-ILD and ILD groups [24.3 (15.9, 48.9) vs. 18.9 (12.7, 27.3), P > 0.05], and Crs was lower after PPV treatment in both groups, but without significant difference [non-ILD group: 22.7 (15.2, 27.1) vs. 24.3 (15.9, 48.9); ILD group: 16.2 (12.8, 25.6) vs. 18.9 (12.7, 27.3), both P > 0.05]. (4) The 60-day mortality in ILD group was significantly higher than that in non-ILD group [88.2% (15/17) vs. 57.9% (11/19), P = 0.047). It was shown by Kaplan-Meier curves that 60-day survival patients in ILD group was significantly lower than those in non-ILD group (χ2 = 5.658, P = 0.017). CONCLUSIONS: PPV can improve oxygenation in severe ARDS. Compared with non-ILD group, though the compliance of respiratory system in ILD group is increased during PPV, long-term effect is better in non-ILD group.