Factors Associated With Prolonged Ventilation in Patients Receiving Prone Positioning Protocol With Muscle Relaxants for Severe COVID-19 Pneumonia.

BACKGROUND: Prone positioning and neuromuscular blocking agents (NMBAs) are frequently used to treat severe respiratory failure from COVID-19 pneumonia. Prone positioning has shown to improve mortality, whereas NMBAs are used to prevent ventilator asynchrony and reduce patient self-inflicted lung injury. However, despite the use of lung-protective strategies, high death rates in this patient population have been reported. METHODS: We retrospectively examined the factors affecting prolonged mechanical ventilation in patients receiving prone positioning plus muscle relaxants. The medical records of 170 patients were reviewed. Subjects were divided into 2 groups according to ventilator-free days (VFDs) at day 28. Whereas subjects with VFDs < 18 d were defined as prolonged mechanical ventilation, subjects with VFDs ≥18 d were defined as short-term mechanical ventilation. Subjects' baseline status, status at ICU admission, therapy before ICU admission, and treatment in the ICU were studied. RESULTS: Under the proning protocol for COVID-19, the mortality rate in our facility was 11.2%. The prognosis may be improved by avoiding lung injury in the early stages of mechanical ventilation. According to multifactorial logistic regression analysis, persistent SARS-CoV-2 viral shedding in blood (P = .027), higher daily corticosteroid use before ICU admission (P = .007), delayed recovery of lymphocyte count (P < .001), and higher maximal fibrinogen degradation products (P = .039) were associated with prolonged mechanical ventilation. A significant relationship was found between daily corticosteroid use before admission and VFDs by squared regression analysis (y = -0.00008522x2 + 0.01338x + 12.8; x: daily corticosteroids dosage before admission [prednisolone mg/d]; y: VFDs/28 d, R2 = 0.047, P = .02). The peak point of the regression curve was 13.4 d at 78.5 mg/d of the equivalent prednisolone dose, which corresponded to the longest VFDs. CONCLUSIONS: Persistent SARS-CoV-2 viral shedding in blood, high corticosteroid dose from the onset of symptoms to ICU admission, slow recovery of lymphocyte counts, and high levels of fibrinogen degradation products after admission were associated with prolonged mechanical ventilation in subjects with severe COVID-19 pneumonia.

Personalized ventilatory strategy based on lung recruitablity in COVID-19-associated acute respiratory distress syndrome: a prospective clinical study.

BACKGROUND: Heterogeneity is an inherent nature of ARDS. Recruitment-to-inflation ratio has been developed to identify the patients who has lung recruitablity. This technique might be useful to identify the patients that match specific interventions, such as higher positive end-expiratory pressure (PEEP) or prone position or both. We aimed to evaluate the physiological effects of PEEP and body position on lung mechanics and regional lung inflation in COVID-19-associated ARDS and to propose the optimal ventilatory strategy based on recruitment-to-inflation ratio. METHODS: Patients with COVID-19-associated ARDS were consecutively enrolled. Lung recruitablity (recruitment-to-inflation ratio) and regional lung inflation (electrical impedance tomography [EIT]) were measured with a combination of body position (supine or prone) and PEEP (low 5 cmH2O or high 15 cmH2O). The utility of recruitment-to-inflation ratio to predict responses to PEEP were examined with EIT. RESULTS: Forty-three patients were included. Recruitment-to-inflation ratio was 0.68 (IQR 0.52-0.84), separating high recruiter versus low recruiter. Oxygenation was the same between two groups. In high recruiter, a combination of high PEEP with prone position achieved the highest oxygenation and less dependent silent spaces in EIT (vs. low PEEP in both positions) without increasing non-dependent silent spaces in EIT. In low recruiter, low PEEP in prone position resulted in better oxygenation (vs. both PEEPs in supine position), less dependent silent spaces (vs. low PEEP in supine position) and less non-dependent silent spaces (vs. high PEEP in both positions). Recruitment-to-inflation ratio was positively correlated with the improvement in oxygenation and respiratory system compliance, the decrease in dependent silent spaces, and was inversely correlated with the increase in non-dependent silent spaces, when applying high PEEP. CONCLUSIONS: Recruitment-to-inflation ratio may be useful to personalize PEEP in COVID-19-associated ARDS. Higher PEEP in prone position and lower PEEP in prone position decreased the amount of dependent silent spaces (suggesting lung collapse) without increasing the amount of non-dependent silent spaces (suggesting overinflation) in high recruiter and in low recruiter, respectively.

Association between tracheostomy and survival in patients with coronavirus disease 2019 who require prolonged mechanical ventilation for more than 14 days: A multicenter cohort study.

OBJECTIVE: Tracheostomy is a common procedure with potential prognostic advantages for patients who require prolonged mechanical ventilation (PMV). Early recommendations for patients with coronavirus disease 2019 (COVID-19) suggested delayed or limited tracheostomy considering the risk for viral transmission to clinicians. However, updated guidelines for tracheostomy with appropriate personal protective equipment have revised its indications. This study aimed to evaluate the association between tracheostomy and prognosis in patients with COVID-19 requiring PMV. METHODS: This was a multicenter, retrospective cohort study using data from the nationwide Japanese Intensive Care PAtient Database. We included adult patients aged ≥16 years who were admitted to the intensive care unit (ICU) due to COVID-19 and who required PMV (for >14 days or until performance of tracheostomy). The primary outcome was hospital mortality, and the association between implementation of tracheostomy and patient prognosis was assessed using weighted Cox proportional hazards regression analysis with inverse probability of treatment weighting (IPTW) using the propensity score to address confounders. RESULTS: Between January 2020 and February 2021, 453 patients with COVID-19 were observed. Data from 109 patients who required PMV were analyzed: 66 (60.6%) underwent tracheostomy and 38 (34.9%) died. After adjusting for potential confounders using IPTW, tracheostomy implementation was found to significantly reduce hospital mortality (hazard ratio [HR]: 0.316, 95% confidence interval [CI]: 0.163-0.612). Patients who underwent tracheostomy had a similarly decreased ICU and 28-day mortality (HR: 0.269, 95% CI: 0.124-0.581; HR 0.281, 95% CI: 0.094-0.839, respectively). A sensitivity analysis using different definitions of PMV duration consistently showed reduced mortality in patients who underwent tracheostomy. CONCLUSION: The implementation of tracheostomy was associated with favorable patient prognosis among patients with COVID-19 requiring PMV. Our findings support proactive tracheostomy in critically ill patients with COVID-19 requiring mechanical ventilation for >14 days.

Timing of tracheostomy and patient outcomes in critically ill patients requiring extracorporeal membrane oxygenation: a single-center retrospective observational study.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is an integral method of life support in critically ill patients with severe cardiopulmonary failure; however, such patients generally require prolonged mechanical ventilation and exhibit high mortality rates. Tracheostomy is commonly performed in patients on mechanical ventilation, and its early implementation has potential advantages for favorable patient outcomes. This study aimed to investigate the association between tracheostomy timing and patient outcomes, including mortality, in patients requiring ECMO. METHODS: We conducted a single-center retrospective observational study of consecutively admitted patients who were supported by ECMO and underwent tracheostomy during intensive care unit (ICU) admission at a tertiary care center from April 2014 until December 2021. The primary outcome was hospital mortality. Using the quartiles of tracheostomy timing, the patients were classified into four groups for comparison. The association between the quartiles of tracheostomy timing and mortality was explored using multivariable logistic regression models. RESULTS: Of the 293 patients treated with ECMO, 98 eligible patients were divided into quartiles 1 (≤ 15 days), quartile 2:16-19 days, quartile 3:20-26 days, and 4 (> 26 days). All patients underwent surgical tracheostomy and 35 patients underwent tracheostomy during ECMO. The complications of tracheostomy were comparable between the groups, whereas the duration of ECMO and ICU length of stay increased significantly as the quartiles of tracheostomy timing increased. Patients in quartile 1 had the lowest hospital mortality rate (19.2%), whereas those in quartile 4 had the highest mortality rate (50.0%). Multivariate logistic regression analysis showed a significant association between the increment of the quartiles of tracheostomy timing and hospital mortality (adjusted odds ratio for quartile increment:1.55, 95% confidence interval 1.03-2.35, p for trend = 0.037). CONCLUSIONS: The timing of tracheostomy in patients requiring ECMO was significantly associated with patient outcomes in a time-dependent manner. Further investigation is warranted to determine the optimal timing of tracheostomy in terms of mortality.

Control of blood glucose levels by an artificial pancreas in patients with severe coronavirus disease 2019 pneumonia.

BACKGROUND: Many patients with severe coronavirus disease 2019 (COVID-19) pneumonia experience hyperglycemia. It is often difficult to control blood glucose (BG) levels in such patients using standard intravenous insulin infusion therapy. Therefore, we used an artificial pancreas. This study aimed to compare the BG status of the artificial pancreas with that of standard therapy. METHODS: Fifteen patients were included in the study. BG values and the infusion speed of insulin and glucose by the artificial pancreas were collected. Arterial BG and administration rates of insulin, parenteral sugar, and enteral sugar were recorded during the artificial pancreas and standard therapy. The target BG level was 200 mg/dl. RESULTS: Arterial BG was highly correlated with BG data from the artificial pancreas. A higher BG slightly increased the difference between the BG data from the artificial pancreas and arterial BS. No significant difference in arterial BG was observed between the artificial pancreas and standard therapy. However, the standard deviation with the artificial pancreas was smaller than that under standard therapy (p < 0.0001). More points within the target BG range were achieved with the artificial pancreas (180-220 mg/dl) than under standard therapy. The hyperglycemic index of the artificial pancreas (8.7 ± 15.6 mg/dl) was lower than that of standard therapy (16.0 ± 21.5 mg/dl) (p = 0.0387). No incidence of hypoglycemia occurred under the artificial pancreas. CONCLUSIONS: The rate of achieving target BG was higher using artificial pancreas than with standard therapy. An artificial pancreas helps to control BG in critically ill patients.

Trends in survival during the pandemic in patients with critical COVID-19 receiving mechanical ventilation with or without ECMO: analysis of the Japanese national registry data.

BACKGROUND: The survival rate of patients with critical coronavirus disease-19 (COVID-19) over time is inconsistent in different settings. In Japan, a national database was organized to monitor and share the patient generation across the country in an immediate response to the COVID-19 pandemic. This study aimed to evaluate changes in survival over time and the prognostic factors in critical COVID-19 patients receiving mechanical ventilation with/without extracorporeal membrane oxygenation (ECMO) using the largest database in Japan. METHODS: This is a prospective observational cohort study of patients admitted to intensive care units in Japan with fatal COVID-19 pneumonia receiving mechanical ventilation and/or ECMO. We developed a prospective nationwide registry covering > 80% of intensive care units in Japan, and analyzed the association between patients' backgrounds, institutional ECMO experience, and timing of treatment initiation and prognosis between February 2020 and November 2021. Prognostic factors were evaluated by Kaplan-Meier analysis and Cox proportional hazards analysis. RESULTS: A total of 9418 patients were ventilated, of whom 1214 (13%) received ECMO. The overall survival rate for ventilated patients was 79%, 65% for those receiving ECMO. There have been five outbreaks in Japan to date. The survival rate of ventilated patients increased from 76% in the first outbreak to 84% in the fifth outbreak (p < 0.001). The survival rate of ECMO patients remained unchanged at 60-68% from the first to fifth outbreaks (p = 0.084). Age of ≥ 59 (hazard ratio [HR] 2.17; 95% confidence interval [CI] 1.76-2.68), ventilator days of ≥ 3 before starting ECMO (HR 1.91; 95% CI 1.57-2.32), and institutional ECMO experiences of ≥ 11 (HR 0.70; 95% CI 0.58-0.85) were independent prognostic factors for ECMO. CONCLUSIONS: During five COVID-19 outbreaks in Japan, the survival rate of ventilated patients tended to have gradually improved, and that of ECMO patients did not deteriorate. Older age, longer ventilator days before starting ECMO, and fewer institutional ECMO experiences may be independent prognostic factors for critical COVID-19 patients receiving ECMO.

Ivermectin administration is associated with lower gastrointestinal complications and greater ventilator-free days in ventilated patients with COVID-19: A propensity score analysis.

INTRODUCTION: COVID-19 patients have been reported to have digestive symptoms with poor outcome. Ivermectin, an antiparasitic drug, has been used in COVID-19 patients. The objective of this study was to evaluate whether ivermectin has effects on gastrointestinal complications and ventilator-free days in ventilated patients with COVID-19. METHODS: COVID-19 patients who were mechanically ventilated in the ICU were included in this study. The ventilated patients who received ivermectin within 3 days after admission were assigned to the Ivermectin group, and the others were assigned to the Control group. Patients in the Ivermectin group received ivermectin 200 µg/kg via nasal tube. The incidence of gastrointestinal complications and ventilator-free days within 4 weeks from admission were evaluated as clinical outcomes using a propensity score with the inverse probability weighting method. RESULTS: We included 88 patients in this study, of whom 39 patients were classified into the Ivermectin group, and 49 patients were classified into the Control group. The hazard ratio for gastrointestinal complications in the Ivermectin group as compared with the Control group was 0.221 (95% confidence interval [CI], 0.057 to 0.855; p = 0.029) in a Cox proportional-hazard regression model. The odds ratio for ventilator-free days as compared with the Control group was 1.920 (95% CI, 1.076 to 3.425; p = 0.027) in a proportional odds logistic regression model. CONCLUSIONS: Ivermectin improved gastrointestinal complications and the number of ventilator-free days in severe COVID-19 patients undergoing mechanical ventilation. Prevention of gastrointestinal symptoms by SARS-Cov-2 might be associated with COVID-19 outcome.

ACE2-like carboxypeptidase B38-CAP protects from SARS-CoV-2-induced lung injury.

Angiotensin-converting enzyme 2 (ACE2) is a receptor for cell entry of SARS-CoV-2, and recombinant soluble ACE2 protein inhibits SARS-CoV-2 infection as a decoy. ACE2 is a carboxypeptidase that degrades angiotensin II, thereby improving the pathologies of cardiovascular disease or acute lung injury. Here we show that B38-CAP, an ACE2-like enzyme, is protective against SARS-CoV-2-induced lung injury. Endogenous ACE2 expression is downregulated in the lungs of SARS-CoV-2-infected hamsters, leading to elevation of angiotensin II levels. Recombinant Spike also downregulates ACE2 expression and worsens the symptoms of acid-induced lung injury. B38-CAP does not neutralize cell entry of SARS-CoV-2. However, B38-CAP treatment improves the pathologies of Spike-augmented acid-induced lung injury. In SARS-CoV-2-infected hamsters or human ACE2 transgenic mice, B38-CAP significantly improves lung edema and pathologies of lung injury. These results provide the first in vivo evidence that increasing ACE2-like enzymatic activity is a potential therapeutic strategy to alleviate lung pathologies in COVID-19 patients.

Individualized ventilatory management in patients with COVID-19-associated acute respiratory distress syndrome.

Due to the coronavirus disease 2019 pandemic, the number of coronavirus disease 2019-associated acute respiratory distress syndrome is rapidly increasing. The heterogeneity of coronavirus disease 2019-associated acute respiratory distress syndrome contributes to the complexity of managing patients. Here we described two patients with coronavirus disease 2019-associated acute respiratory distress syndrome showing that the bedside physiological approach including careful evaluation of respiratory system mechanics and visualization of ventilation with electrical impedance tomography was useful to individualize ventilatory management.