Reintubation in COVID-19 patients: a multicenter observational study in Japan (J-RECOVER study)

Background Reintubation is not an uncommon occurrence following extubation and discontinuation of mechanical ventilation. In COVID-19 patients, the proportion of reintubation may be higher than that of non-COVID-19 patients. Furthermore, COVID-19 patients may have a higher risk for developing laryngotracheal stenosis, along with a higher proportion of reintubation than in non-COVID-19 patients. Our understanding of the proportion of reintubation in COVID-19 patients is limited in Japan. Additionally, the reasons for reintubation have not been adequately examined in previous studies outside of Japan. Thus, the present study aimed to describe the proportion and causes of reintubation among COVID-19 patients in Japan. Methods This was a multicenter observational study that included 64 participating centers across Japan. This study included mechanically ventilated COVID-19 patients who were discharged between April 1, 2020 and September 30, 2020. The outcomes examined were the proportion and causes of reintubation. Results A total of 373 patients were eligible for inclusion in the current analysis. The median age of patients was 64 years and 80.4% were male. Reintubation was required for 35 patients (9.4%) and the most common causes for reintubation were respiratory failure (71.4%;n = 25) and laryngotracheal stenosis (8.6%;n = 3). Conclusions The proportion of reintubation among COVID-19 patients in Japan was relatively low. Respiratory failure was the most common cause for reintubation. Reintubation due to laryngotracheal stenosis accounted for only a small fraction of all reintubated COVID-19 patients in Japan.

Breath-by-breath P0.1 measured on quasi-occlusion via Hamilton C6 may result in underestimation of respiratory drive and inspiratory effort.

We aimed to identify the threshold for P0.1 in a breath-by-breath manner measured by the Hamilton C6 on quasi-occlusion for high respiratory drive and inspiratory effort. In this prospective observational study, we analyzed the relationships between airway P0.1 on quasi-occlusion and esophageal pressure (esophageal P0.1 and esophageal pressure swing). We also conducted a linear regression analysis and derived the threshold of airway P0.1 on quasi-occlusion for high respiratory drive and inspiratory effort. We found that airway P0.1 measured on quasi-occlusion had a strong positive correlation with esophageal P0.1 measured on quasi-occlusion and esophageal pressure swing, respectively. Additionally, the P0.1 threshold for high respiratory drive and inspiratory effort were calculated at approximately 1.0 cmH2O from the regression equations. Our calculations suggest a lower threshold of airway P0.1 measured by the Hamilton C6 on quasi-occlusion than that which has been previously reported.

Reintubation in COVID-19 patients: a multicenter observational study in Japan (J-RECOVER study).

BACKGROUND: Reintubation is not an uncommon occurrence following extubation and discontinuation of mechanical ventilation. In COVID-19 patients, the proportion of reintubation may be higher than that of non-COVID-19 patients. Furthermore, COVID-19 patients may have a higher risk for developing laryngotracheal stenosis, along with a higher proportion of reintubation than in non-COVID-19 patients. Our understanding of the proportion of reintubation in COVID-19 patients is limited in Japan. Additionally, the reasons for reintubation have not been adequately examined in previous studies outside of Japan. Thus, the present study aimed to describe the proportion and causes of reintubation among COVID-19 patients in Japan. METHODS: This was a multicenter observational study that included 64 participating centers across Japan. This study included mechanically ventilated COVID-19 patients who were discharged between April 1, 2020 and September 30, 2020. The outcomes examined were the proportion and causes of reintubation. RESULTS: A total of 373 patients were eligible for inclusion in the current analysis. The median age of patients was 64 years and 80.4% were male. Reintubation was required for 35 patients (9.4%) and the most common causes for reintubation were respiratory failure (71.4%; n = 25) and laryngotracheal stenosis (8.6%; n = 3). CONCLUSIONS: The proportion of reintubation among COVID-19 patients in Japan was relatively low. Respiratory failure was the most common cause for reintubation. Reintubation due to laryngotracheal stenosis accounted for only a small fraction of all reintubated COVID-19 patients in Japan.

Favipiravir for Treatment of Outpatients With Asymptomatic or Uncomplicated Coronavirus Disease 2019: A Double-Blind, Randomized, Placebo-Controlled, Phase 2 Trial.

BACKGROUND: Favipiravir, an oral, RNA-dependent RNA polymerase inhibitor, has in vitro activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite limited data, favipiravir is administered to patients with coronavirus disease 2019 (COVID-19) in several countries. METHODS: We conducted a phase 2, double-blind, randomized controlled outpatient trial of favipiravir in asymptomatic or mildly symptomatic adults with a positive SARS-CoV-2 reverse-transcription polymerase chain reaction assay (RT-PCR) within 72 hours of enrollment. Participants were randomized to receive placebo or favipiravir (1800 mg twice daily [BID] day 1, 800 mg BID days 2-10). The primary outcome was SARS-CoV-2 shedding cessation in a modified intention-to-treat (mITT) cohort of participants with positive enrollment RT-PCRs. Using SARS-CoV-2 amplicon-based sequencing, we assessed favipiravir's impact on mutagenesis. RESULTS: We randomized 149 participants with 116 included in the mITT cohort. The participants' mean age was 43 years (standard deviation, 12.5 years) and 57 (49%) were women. We found no difference in time to shedding cessation overall (hazard ratio [HR], 0.76 favoring placebo [95% confidence interval {CI}, .48-1.20]) or in subgroups (age, sex, high-risk comorbidities, seropositivity, or symptom duration at enrollment). We detected no difference in time to symptom resolution (initial: HR, 0.84 [95% CI, .54-1.29]; sustained: HR, 0.87 [95% CI, .52-1.45]) and no difference in transition mutation accumulation in the viral genome during treatment. CONCLUSIONS: Our data do not support favipiravir at commonly used doses in outpatients with uncomplicated COVID-19. Further research is needed to ascertain if higher favipiravir doses are effective and safe for patients with COVID-19. CLINICAL TRIALS REGISTRATION: NCT04346628.

Antiviral therapy for COVID-19: Derivation of optimal strategy based on past antiviral and favipiravir experiences.

Favipiravir, a broad-spectrum RNA-dependent RNA polymerase inhibitor, inhibits the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at significantly lower concentrations than the plasma trough levels achieved by the dosage adopted for influenza treatment and exhibits efficacy against coronavirus disease 2019 (COVID-19) pneumonia. Although high doses of favipiravir are required due to the molecule being a purine analog, its conversion into the active form in infected cells with active viral RNA synthesis enhances the antiviral specificity and selectivity as a chain terminator with lethal mutagenesis. Another characteristic feature is the lack of generation of favipiravir-resistant virus. COVID-19 pneumonia is caused by strong cell-mediated immunity against virus-infected cells, and the inflammatory response induced by adaptive immunity continues to peak for 3 to 5 days despite antiviral treatment. This has also been observed in herpes zoster (HZ) and cytomegalovirus (CMV) pneumonia. Inflammation due to an immune response may mask the effectiveness of favipiravir against COVID-19 pneumonia. Favipiravir significantly shortened the recovery time in patients with mild COVID-19 pneumonia by 3 days with the start of treatment by the 5th day of symptom onset. Since both CMV and COVID-19 pneumonia are caused by adaptive immunity and prevention of cytomegalovirus pneumonia is the standard treatment due to difficulties in treating refractory CMV pneumonia, COVID-19 pneumonia should be prevented with early treatment as well. In the present study, we have comprehensively reviewed the optimal antiviral therapy for COVID-19 based on clinical trials of favipiravir for the treatment of COVID-19 pneumonia and the concurrently established therapies for other viral infections, particularly HZ and CMV pneumonia. Optimally, antivirals should be administered immediately after COVID-19 diagnosis, similar to that after influenza diagnosis, to prevent COVID-19 pneumonia and complications resulting from microangiopathy.

Prevalence of COVID-19 Mimics in the Emergency Department.

Objective Due to the lack of specific clinical manifestations and symptoms, it is difficult to distinguish COVID-19 from mimics. A common pitfall is to rush to make a diagnosis when encountering a patient with COVID-19-like symptoms. The present study describes a series of COVID-19 mimics using an outpatient database collected from a designated COVID-19 healthcare facility in Tokyo, Japan. Methods We established an emergency room (ER) tailored specifically for patients with suspected or confirmed COVID-19 called the "COVID-ER." In this single-center retrospective cohort study, we enrolled patients who visited the COVID-ER from February 1 to September 5, 2020. The outcomes included the prevalence of COVID-19, admission, potentially fatal diseases and final diagnosis. Results We identified 2,555 eligible patients. The median age was 38 (interquartile range, 26-57) years old. During the study period, the prevalence of COVID-19 was 17.9% (457/2,555). Non-COVID-19 diagnoses accounted for 82.1% of all cases. The common cold had the highest prevalence and accounted for 33.0% of all final diagnoses, followed by gastroenteritis (9.4%), urinary tract infections (3.8%), tonsillitis (2.9%), heat stroke (2.6%) and bacterial pneumonia (2.1%). The prevalence of potentially fatal diseases was 14.2% (298/2,098) among non-COVID-19 patients. Conclusion Several potentially fatal diseases remain masked among the wave of COVID-19 mimics. It is imperative that a thorough differential diagnostic panel be considered prior to the rendering of a COVID-19 diagnosis.

Abnormal pulmonary function and imaging studies in critical COVID-19 survivors at 100 days after the onset of symptoms.

BACKGROUND: The long-term repercussions of critical COVID-19 on pulmonary function and imaging studies remains unexplored. In this study, we investigated the pulmonary function and computed tomography (CT) findings of critical COVID-19 patients approximately 100 days after symptom onset. METHODS: We retrospectively extracted data on critical COVID-19 patients who received invasive mechanical ventilation during hospitalization from April to December 2020 and evaluated their pulmonary function, residual respiratory symptoms and radiographic abnormalities on CT. RESULTS: We extracted 17 patients whose median age was 63 (interquartile range [IQR], 59-67) years. The median lengths of hospitalization and mechanical ventilation were 23 (IQR, 18-38) and 9 (IQR, 6-13) days, respectively. At 100 days after symptom onset, the following pulmonary function abnormalities were noted in 8 (47%) patients: a diffusion capacity of the lung for carbon monoxide (%DLCO) of <80% for 6 patients (35%); a percent vital capacity (%VC) of <80% for 4 patients (24%); and a forced expiratory volume in one second/forced vital capacity (FEV1%) of <70% for 1 patient (6%) who also presented with %DLCO and %VC abnormalities. Twelve (71%) patients reported residual respiratory symptoms and 16 (94%) showed abnormalities on CT. CONCLUSIONS: Over 90% of the critical COVID-19 patients who underwent invasive mechanical ventilation continued presenting with abnormal imaging studies and 47% of the patients presented with abnormal pulmonary function 100 days after symptom onset. The extent of the residual CT findings might be associated with the degree of abnormal pulmonary function in critical COVID-19 survivors.

Prevalence of thromboembolic events and status of prophylactic anticoagulant therapy in hospitalized patients with COVID-19 in Japan.

INTRODUCTION: One of the most prominent and concerning complications associated with coronavirus disease 2019 (COVID-19) is venous and arterial thromboembolisms. The aim of the present study was to delineate the prevalence of thromboembolic events and the current status of prophylactic anticoagulation therapy in patients with COVID-19 in Japan. METHODS: Between February 1 and August 31, 2020, we performed a dual-center, retrospective cohort study based on data obtained from the medical charts of COVID-19 patients admitted to healthcare facilities in Japan. The primary outcome was any thromboembolic event including pulmonary embolism (PE), deep vein thrombosis (DVT), myocardial infarction, ischemic stroke and other systemic thromboemboli. RESULTS: During the study period, we extracted 628 consecutive patients admitted for COVID-19. Prophylactic anticoagulant therapy was administered in 63 (10%) patients of whom 20 (31.7%) were admitted to the intensive care unit (ICU). Thromboembolic events occurred in 18 (2.9%) patients (14.3% of patients in ICU and 2.2% of patients in the general wards). DVT were detected in 13 (2.1%) patients, PE in 11 (1.8%), and both DVT and PE in 6 (0.96%) patients. An increasing prevalence in thromboembolic events was noted with progressive clinical severity. Overall in-hospital mortality was 4.8%. CONCLUSIONS: Prophylactic anticoagulation therapy was administered in only 10% of all hospitalized COVID-19 patients. The prevalence of any thromboembolic events was 2.9% in COVID-19 patients with most events occurring in severe and critical patients. Therefore, prophylactic anticoagulation therapy may be warranted in severe and critical patients but in asymptomatic to moderate patients the practice remains controversial.

A comparison on the percentage of polymerase chain reaction positivity for SARS-CoV-2 between Public Health Center referrals and direct walk-in patients: A single center retrospective analysis in Tokyo.

INTRODUCTION: The Public Health Center (PHC)-known as hokenjo in Japan-assume a crucial role in disease control. Coronavirus disease 2019 (COVID-19) is one of many designated infectious diseases monitored by the agency. During the present pandemic, patients who suspected COVID-19 were instructed to call the Coronavirus Consultation Center in the PHC prior to visiting the hospital. The aim of this study was to elucidate the differences in polymerase chain reaction (PCR) positivity between PHC referrals and direct walk-in patients. METHODS: The present was a single-center, retrospective cohort study conducted at the Tokyo Metropolitan Hospital from March to September, 2020. Patients who received a PCR test for SARS-CoV-2 were included and categorized into the PHC referral or direct walk-in groups. The outcomes included the total number of patients undergoing PCR tests and the percentage of PCR positivity in each group. RESULTS: We identified 1680 patients (781 PHC referred and 899 direct walk-in groups). The percentage of PCR positivity did not significantly differ between the PHC referral and direct walk-in groups during the first wave (30.5% vs. 29.2%; p = 0.78). PCR positivity was significantly higher in the PHC referral group than the direct walk-in group during the second wave (30.1% vs. 23.1%; p = 0.051) and entire study period (30.2% vs. 24.7%; p = 0.011). CONCLUSIONS: Despite health authority recommendations, the number of direct walk-in patients were higher than PHC referral patients. The percentage of PCR positivity was significantly higher in the PHC referral group than in the direct walk-in group.