Efficacy and safety of convalescent plasma therapy for severe COVID-19 patients：case series study and literature review

Background Coronavirus disease 2019 (COVID-19) is a new acute respiratory infectious disease which can lead to multiple organ dysfunction in severe patients. However, it is still a lack of effective antiviral drugs for COVID-19. Herein we investigated the efficacy and safety of convalescent plasma (CP) in the treatment of severe COVID-19, with an attempt to explore new therapeutic method. Methods Clinical data of three imported severe COVID-19 patients with CP treatment, who were under quarantine and treated in a designated COVID-19 hospital from March 2020 to April 2020, were collected and analyzed. Results The three patients were clinically classified as severe type, including one male and two females, aged 57, 59 and 65 years old, respectively. The main underling diseases included hypertension, diabetes, sequela of cerebral infarction and postoperative thyroid adenoma. The common symptoms included cough, fever and short of breath. All the patients received antiviral drugs and other supportive treatments. Additionally, CP treatment was also administrated for them. Forty-eight to seventy-two hours after CP transfusion, all the patients improved with alleviated symptoms, elevated arterial oxygen saturation, decreased C-reactive protein and interleukin-6 markers. And the total lymphocytes, T lymphocytes (CD3+) and their subsets (CD4+, CD8+) also obviously increased. Repeated chest CTs also showed obvious absorption of lesions in bilateral lung. Only one patient had mild allergic reaction during CP infusion, but no severe adverse reactions were found. Conclusions The early application of CP for severe COVID-19 patients can improve the condition rapidly, and the therapy is generally effective and safe.

The physiology of extracorporeal membrane oxygenation: The Fick principle

Extracorporeal membrane oxygenation (ECMO) can be delivered in veno-arterial (VA) and veno-venous (VV) configurations based on the cannulation strategy. VA and VV ECMO are delivered primarily for haemodynamic and respiratory support in patients with severe heart and lung failure, respectively. The Fick principle describes the relationship between blood flow and oxygen consumption – key parameters in the physiological management of extracorporeal support. This review will discuss the application of the Fick principle in: (i) recirculation in VV ECMO; (ii) the quantification of oxygen delivery (DO2) in VV ECMO and (iii) the quantification of transpulmonary blood flow and systemic arterial oxygen saturation in VA ECMO.

Vitamin D Immune-Mediated Responses and SARS-CoV-2 Infection: Clinical Implications in COVID-19

Active vitamin D is a true steroid hormone with pleiotropic biological effects that go beyond the classical concept of bone metabolism regulation. In fact, adequate serum levels of 25-hydroxyvitamin D (>40 ng/mL) are required to support several biological functions, including the control of innate and adaptive immunity in course of infectious, inflammatory and autoimmune diseases. SARS-CoV-2 is responsible for the COVID-19 pandemic and deficient/insufficient serum levels of 25-hydroxyvitamin D are reported in very large cohorts of patients. Of note, vitamin D is involved in different pathophysiological processes, such as expression of SARS-CoV-2 receptor (ACE2), activation of innate (neutrophils with their extracellular traps, monocytes/macrophages, dendritic cells, natural killer cells) and adaptive (T and B lymphocytes) immune cells and clinical manifestations, such as coagulation/thrombotic disorders and acute respiratory distress syndrome. Randomized clinical trials regarding vitamin D supplementation in COVID-19 patients have shown favorable effects on the control of inflammation markers, arterial oxygen saturation/inspired fraction of oxygen ratio, admission to hospital intensive care units and mortality. A target of serum 25-hydroxyvitamin D > 50 ng/mL has been identified as protective for the course of COVID-19, potentially playing an ancillary role in the treatment of the disease.

427 The role of virtual visits in cardiology: from the pandemic era to future perspectives

Aims During the Coronavirus Disease 2019 (COVID-19) pandemic in-person visits were reduced to prevent potential risk of exposure. Virtual visits (VVs) represent an innovative model to take care of patients with cardiac implantable electronic devices (CIEDs). The aim of this study is to evaluate the safety and feasibility of VV in the management of CIED patients. Methods and results We performed a prospective study including all CIED patients who received a VV from July 2020 to July 2021. Blood pressure, arterial oxygen saturation, heart rate, and body weight were registered by the patient. Moreover, we sent to the patient a questionnaire to evaluate the patients’ satisfaction about VV. We enrolled 182 patients in the study period. The mean age of patients was 70.2 ± 13.5 years-old and the majority (61.1%) was male. In two cases, VVs were not performed due to technical issues. Overall, 70.9% of patients utilized a smartphone, while 20.1% and 9% used, respectively, a tablet or a personal computer. The mean duration of VV was 27.8 ± 7.8 min. Patients helped by a caregiver were 64 (35.2%). One urgent/emergent in-person visit was performed in a patient with acute heart failure. Overall, VV was preferred to in-person evaluation. Conclusion VV is a safe and feasible approach to follow-up CIED patients. A high degree of patient satisfaction was reached after VV. The use of VV has promising potential and should be implemented beyond COVID-19 period and integrated in the healthcare system as a new model of care.

428 The role of virtual visits in COVID-19 cardiovascular patients

Aims The outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic forced a reorganization of the healthcare system. In order to prevent potential risk of exposure, virtual visit (VV) has been implemented in the treatment and follow-up of COVID-19 patients with cardiovascular diseases. The aim of this study is to evaluate the feasibility and efficacy of VV in the management of post COVID-19 cardiovascular patients. Methods and results We enrolled all patients with cardiovascular comorbidities tested negative for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) and discharged from our Cardiology Department from January 2021 to June 2021. We scheduled a VV after 30 days from discharge to check the clinical status of the patients, optimize therapy, and establish a Follow-up protocol. Blood pressure, arterial oxygen saturation, heart rate and body weight were registered. To evaluate the patients’ satisfaction of VV, a questionnaire was administered. We performed 25 VVs in the study period; the mean age of patients was 67.5 ± 15.6 and male were 15 (65.2%). The mean duration of VV was 25.9 ± 4.6 min. The caregiver had an active role in nine (36%) cases. No urgent/emergent in-person examinations were performed. A high degree of patient satisfaction was reached and VV was preferred to in-person evaluation. Conclusions VV visit was useful to Follow-up post COVID-19 cardiovascular patients. A high degree of patient satisfaction was reached without jeopardizing quality of care.

Mid Term Results of Fenestrated Intra-Extracardiac Fontan Procedure: Insights, Experiences and Expectations

Background: Intraextracardiac Fontan procedure aimed to combine the advantages of lateral tunnel and extracardiac conduit modifications of the original technique. Herein, we present our experience in our patients with intraextracardiac fenestrated Fontan Procedure. Methods: A retrospective analysis was performed in order to evaluate intraextracardiac fenestrated Fontan patients between 2014 and 2021. Seventeen patients were operated on with a mean age and body weight of 9.1 ± 5.5 years and 28.6 ± 14.6 kg. Results: Sixteen patients (94%) were palliated as univentricular physiology with hypoplasia of one of the ventricles. One patient (6%) with well-developed two ventricles with double outlet right ventricle and complete atrioventricular septal defect had straddling of the chordae prohibiting a biventricular repair. All of the patients had cavopulmonary anastomosis prior to Fontan completion, except one case. Fenestration was performed in all cases. Postoperative mean pulmonary artery pressures and arterial oxygen saturation levels at follow up were 10 ± 2.4 mmHg and 91.3 ± 2.7 %, respectively. Mean duration of pleural drainage was 5.4 ± 2.3 days. All of the fenestrations are patent at a mean follow up period of 4.8 ± 7.7 years, except one case. Any morbidity and mortality were not encountered. Conclusions: The mid-term results of intraextracardiac fenestrated Fontan procedure are encouraging. This procedure may improve the results in a patient population who should be palliated as univentricular physiology, especially in cases with complex cardiac anatomy.

Modified high-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients undergoing bronchoscopy: a randomized clinical trial

Background Hypoxemia frequently occurs during bronchoscopy. High-flow nasal cannula (HFNC) oxygen therapy may be a feasible alternative to prevent the deterioration of gas exchange during bronchoscopy. With the convenience of clinical use in mind, we modified an HFNC using a single cannula. This clinical trial was designed to test the hypothesis that a modified HFNC would decrease the proportion of patients with a single moment of peripheral arterial oxygen saturation (SpO2) < 90% during bronchoscopy. Methods In this single-center, prospective randomized controlled trial, hospitalized patients in the respiratory department in need of diagnostic bronchoscopy were randomly assigned to a modified HFNC oxygen therapy group or a conventional oxygen therapy (COT) group. The primary outcome was the proportion of patients with a single moment of SpO2 < 90% during bronchoscopy. Results Eight hundred and twelve patients were randomized to the modified HFNC (n = 406) or COT (n = 406) group. Twenty-four patients were unable to cooperate or comply with bronchoscopy. Thus, 788 patients were included in the analysis. The proportion of patients with a single moment of SpO2 < 90% during bronchoscopy in the modified HFNC group was significantly lower than that in the COT group (12.5% vs. 28.8%, p < 0.001). There were no significant differences in the fraction of inspired oxygen between the two groups. The lowest SpO2 during bronchoscopy and 5 min after bronchoscopy in the modified HFNC group was significantly higher than that in the COT group. Multivariate analysis showed that a baseline forced vital capacity (FVC) < 2.7 L (OR, 0.276; 95% CI, 0.083–0.919, p = 0.036) and a volume of fluid instilled > 60 ml (OR, 1.034; 95% CI, 1.002–1.067, p = 0.036) were independent risk factors for hypoxemia during bronchoscopy in the modified HFNC group. Conclusions A modified HFNC could decrease the proportion of patients with a single moment of SpO2 < 90% during bronchoscopy. A lower baseline FVC and large-volume bronchoalveolar lavage may predict desaturation during bronchoscopy when using a modified HFNC. Trial registration ClinicalTrials. Gov: NCT02606188. Registered 17 November 2015.

Peripheral microcirculatory alterations are associated with the severity of acute respiratory distress syndrome in COVID-19 patients admitted to intermediate respiratory and intensive care units

Background COVID-19 is primarily a respiratory disease; however, there is also evidence that it causes endothelial damage in the microvasculature of several organs. The aim of the present study is to characterize in vivo the microvascular reactivity in peripheral skeletal muscle of severe COVID-19 patients. Methods This is a prospective observational study carried out in Spain, Mexico and Brazil. Healthy subjects and severe COVID-19 patients admitted to the intermediate respiratory (IRCU) and intensive care units (ICU) due to hypoxemia were studied. Local tissue/blood oxygen saturation (StO2) and local hemoglobin concentration (THC) were non-invasively measured on the forearm by near-infrared spectroscopy (NIRS). A vascular occlusion test (VOT), a three-minute induced ischemia, was performed in order to obtain dynamic StO2 parameters: deoxygenation rate (DeO2), reoxygenation rate (ReO2), and hyperemic response (HAUC). In COVID-19 patients, the severity of ARDS was evaluated by the ratio between peripheral arterial oxygen saturation (SpO2) and the fraction of inspired oxygen (FiO2) (SF ratio). Results Healthy controls (32) and COVID-19 patients (73) were studied. Baseline StO2 and THC did not differ between the two groups. Dynamic VOT-derived parameters were significantly impaired in COVID-19 patients showing lower metabolic rate (DeO2) and diminished endothelial reactivity. At enrollment, most COVID-19 patients were receiving invasive mechanical ventilation (MV) (53%) or high-flow nasal cannula support (32%). Patients on MV were also receiving sedative agents (100%) and vasopressors (29%). Baseline StO2 and DeO2 negatively correlated with SF ratio, while ReO2 showed a positive correlation with SF ratio. There were significant differences in baseline StO2 and ReO2 among the different ARDS groups according to SF ratio, but not among different respiratory support therapies. Conclusion Patients with severe COVID-19 show systemic microcirculatory alterations suggestive of endothelial dysfunction, and these alterations are associated with the severity of ARDS. Further evaluation is needed to determine whether these observations have prognostic implications. These results represent interim findings of the ongoing HEMOCOVID-19 trial. Trial registration ClinicalTrials.gov NCT04689477. Retrospectively registered 30 December 2020.

Cardiopulmonary responses to centrifuge simulated parabolic flight

Introduction: Parabolic flights, by producing short periods of weightlessness, closely simulate microgravity. However, they are still expensive, incur a significant logistics support, and occurrence of any adverse events during such simulation is undesirable. The present study was formulated to explore the feasibility of using a human centrifuge for simulation of parabolic flight to study the cardiopulmonary parameters as an alternative ground-based model. Material and Methods: Twelve healthy male volunteers were subjected to simulated parabolic flight, the profile of which involved exposure to 20 repetitions of hypogravity periods (+0.5 Gz), each interposed between periods of hypergravity phases (+2 Gz), using high-performance human centrifuge. Heart rate (HR), respiratory rate (RR), and arterial oxygen saturation (SpO2) were studied during such a simulation and analyzed using one-way repeated measures ANOVA. Motion sickness assessment questionnaire was administered to the participants after the run. They were also asked to rate their subjective feeling of weightlessness experienced during the run. Results: Comparison of HR revealed a significant difference (F = 22.167, P < 0.001) across 20 loops of different gravity phases. Post hoc analysis revealed that the mean HR of hypergravity phases was significantly higher compared with pre-run 1 G values and that of hypogravity phases. Similarly, HR showed a significant difference across pre-run 1 G, 10th and 20th loops of hypogravity phases (F = 5.672, P = 0.01). Post hoc analysis revealed a significant reduction in HR at 20th loop compared to both pre-run 1 G (P = 0.023) and 10th loop (P = 0.042) values. No significant differences were observed in both RR (F = 1.789, P = 0.148) and SpO2 (F = 1.708, P =0.199) across different gravity phases. The mean overall motion sickness score was found to be 23.6%. Participants rated their subjective feeling of weightlessness between 4 and 6 (mode = 5) on a scale of 1–10. Conclusion: It can be concluded from the results that HR increased during hypergravity conditions and reduced during hypogravity conditions, an expected outcome during parabolic flight. The significant reduction in HR during the 20th loop of hypogravity phase compared to 10th loop and pre-run 1 G conditions indicate a possible association with the duration of exposure. The centrifuge simulated parabolic flight profile designed in our study was able to emanate physiological changes similar to those experienced in actual parabolic flight for HR, RR, and SpO2.