Concurrent use of continuous kidney replacement therapy during extracorporeal membrane oxygenation: what pediatric nephrologists need to know-PCRRT-ICONIC practice points.

Extracorporeal membrane oxygenation (ECMO) provides temporary cardiorespiratory support for neonatal, pediatric, and adult patients when traditional management has failed. This lifesaving therapy has intrinsic risks, including the development of a robust inflammatory response, acute kidney injury (AKI), fluid overload (FO), and blood loss via consumption and coagulopathy. Continuous kidney replacement therapy (CKRT) has been proposed to reduce these side effects by mitigating the host inflammatory response and controlling FO, improving outcomes in patients requiring ECMO. The Pediatric Continuous Renal Replacement Therapy (PCRRT) Workgroup and the International Collaboration of Nephrologists and Intensivists for Critical Care Children (ICONIC) met to highlight current practice standards for ECMO use within the pediatric population. This review discusses ECMO modalities, the pathophysiology of inflammation during an ECMO run, its adverse effects, various anticoagulation strategies, and the technical aspects and outcomes of implementing CKRT during ECMO in neonatal and pediatric populations. Consensus practice points and guidelines are summarized. ECMO should be utilized in patients with severe acute respiratory failure despite the use of conventional treatment modalities. The Extracorporeal Life Support Organization (ELSO) offers guidelines for ECMO initiation and management while maintaining a clinical registry of over 195,000 patients to assess outcomes and complications. Monitoring and preventing fluid overload during ECMO and CKRT are imperative to reduce mortality risk. Clinical evidence, resources, and experience of the nephrologist and healthcare team should guide the selection of ECMO circuit.

Timing of Kidney Replacement Therapy Initiation and Survival during Pediatric Extracorporeal Membrane Oxygenation: An Extracorporeal Life Support Organization Registry Study.

To characterize kidney replacement therapy (KRT) and pediatric extracorporeal membrane oxygenation (ECMO) outcomes and to identify the optimal timing of KRT initiation during ECMO associated with increased survival. Observational retrospective cohort study using the Extracorporeal Life Support Organization Registry database in children (0-18 yo) on ECMO from January 1, 2016, to December 31, 2020. Of the 14,318 ECMO runs analyzed, 26% of patients received KRT during ECMO. Patients requiring KRT before ECMO had increased mortality to ECMO decannulation (29% vs. 17%, OR 1.97, P < 0.001) and to hospital discharge (58% vs. 39%, OR 2.16, P < 0.001). Patients requiring KRT during ECMO had an increased mortality to ECMO decannulation (25% vs. 15%, OR 1.85, P < 0.001) and to hospital discharge (56% vs. 34%, OR 2.47, P < 0.001). Multivariable logistic regression demonstrated that the need for KRT during ECMO was an independent predictor for mortality to ECMO decannulation (OR 1.49, P < 0.001) and to hospital discharge (OR 2.02, P < 0.001). Patients initiated on KRT between 24 and 72 hours after cannulation were more likely to survive to ECMO decannulation and showed a trend towards survival to hospital discharge as compared to those initiated before 24 hours and after 72 hours.

Extracorporeal Life Support Organization Registry International Report 2022: 100,000 Survivors.

The Extracorporeal Life Support Organization (ELSO) maintains the world's largest extracorporeal membrane oxygenation (ECMO) registry by volume, center participation, and international scope. This 2022 ELSO Registry Report describes the program characteristics of ECMO centers, processes of ECMO care, and reported outcomes. Neonates (0-28 days), children (29 days-17 years), and adults (≥18 years) supported with ECMO from 2009 through 2022 and reported to the ELSO Registry were included. This report describes adjunctive therapies, support modes, treatments, complications, and survival outcomes. Data are presented descriptively as counts and percent or median and interquartile range (IQR) by year, group, or level. Missing values were excluded before calculating descriptive statistics. Complications are reported per 1,000 ECMO hours. From 2009 to 2022, 154,568 ECMO runs were entered into the ELSO Registry. Seven hundred and eighty centers submitted data during this time (557 in 2022). Since 2009, the median annual number of adult ECMO runs per center per year increased from 4 to 15, whereas for pediatric and neonatal runs, the rate decreased from 12 to 7. Over 50% of patients were transferred to the reporting ECMO center; 20% of these patients were transported with ECMO. The use of prone positioning before respiratory ECMO increased from 15% (2019) to 44% (2021) for adults during the coronavirus disease-2019 (COVID-19) pandemic. Survival to hospital discharge was greatest at 68.5% for neonatal respiratory support and lowest at 29.5% for ECPR delivered to adults. By 2022, the Registry had enrolled its 200,000th ECMO patient and 100,000th patient discharged alive. Since its inception, the ELSO Registry has helped centers measure and compare outcomes across its member centers and strategies of care. Continued growth and development of the Registry will aim to bolster its utility to patients and centers.

Expert consensus statement on venovenous extracorporeal membrane oxygenation ECMO for COVID-19 severe ARDS: an international Delphi study.

BACKGROUND: The high-quality evidence on managing COVID-19 patients requiring extracorporeal membrane oxygenation (ECMO) support is insufficient. Furthermore, there is little consensus on allocating ECMO resources when scarce. The paucity of evidence and the need for guidance on controversial topics required an international expert consensus statement to understand the role of ECMO in COVID-19 better. Twenty-two international ECMO experts worldwide work together to interpret the most recent findings of the evolving published research, statement formulation, and voting to achieve consensus. OBJECTIVES: To guide the next generation of ECMO practitioners during future pandemics on tackling controversial topics pertaining to using ECMO for patients with COVID-19-related severe ARDS. METHODS: The scientific committee was assembled of five chairpersons with more than 5 years of ECMO experience and a critical care background. Their roles were modifying and restructuring the panel's questions and, assisting with statement formulation in addition to expert composition and literature review. Experts are identified based on their clinical experience with ECMO (minimum of 5 years) and previous academic activity on a global scale, with a focus on diversity in gender, geography, area of expertise, and level of seniority. We used the modified Delphi technique rounds and the nominal group technique (NGT) through three face-to-face meetings and the voting on the statement was conducted anonymously. The entire process was planned to be carried out in five phases: identifying the gap of knowledge, validation, statement formulation, voting, and drafting, respectively. RESULTS: In phase I, the scientific committee obtained 52 questions on controversial topics in ECMO for COVID-19, further reviewed for duplication and redundancy in phase II, resulting in nine domains with 32 questions with a validation rate exceeding 75% (Fig. 1). In phase III, 25 questions were used to formulate 14 statements, and six questions achieved no consensus on the statements. In phase IV, two voting rounds resulted in 14 statements that reached a consensus are included in four domains which are: patient selection, ECMO clinical management, operational and logistics management, and ethics. CONCLUSION: Three years after the onset of COVID-19, our understanding of the role of ECMO has evolved. However, it is incomplete. Tota14 statements achieved consensus; included in four domains discussing patient selection, clinical ECMO management, operational and logistic ECMO management and ethics to guide next-generation ECMO providers during future pandemic situations.

Extracorporeal membrane oxygenation in adults receiving haematopoietic cell transplantation: an international expert statement.

Combined advances in haematopoietic cell transplantation (HCT) and intensive care management have improved the survival of patients with haematological malignancies admitted to the intensive care unit. In cases of refractory respiratory failure or refractory cardiac failure, these advances have led to a renewed interest in advanced life support therapies, such as extracorporeal membrane oxygenation (ECMO), previously considered inappropriate for these patients due to their poor prognosis. Given the scarcity of evidence-based guidelines on the use of ECMO in patients receiving HCT and the need to provide equitable and sustainable access to ECMO, the European Society of Intensive Care Medicine, the Extracorporeal Life Support Organization, and the International ECMO Network aimed to develop an expert consensus statement on the use of ECMO in adult patients receiving HCT. A steering committee with expertise in ECMO and HCT searched the literature for relevant articles on ECMO, HCT, and immune effector cell therapy, and developed opinion statements through discussions following a Quaker-based consensus approach. An international panel of experts was convened to vote on these expert opinion statements following the Research and Development/University of California, Los Angeles Appropriateness Method. The Appraisal of Guidelines for Research and Evaluation statement was followed to prepare this Position Paper. 36 statements were drafted by the steering committee, 33 of which reached strong agreement after the first voting round. The remaining three statements were discussed by all members of the steering committee and expert panel, and rephrased before an additional round of voting. At the conclusion of the process, 33 statements received strong agreement and three weak agreement. This Position Paper could help to guide intensivists and haematologists during the difficult decision-making process regarding ECMO candidacy in adult patients receiving HCT. The statements could also serve as a basis for future research focused on ECMO selection criteria and bedside management.

Synergistic association of fluid overload and acute kidney injury on outcomes in pediatric cardiac ECMO: a retrospective analysis of the KIDMO database.

BACKGROUND: Acute kidney injury (AKI) and fluid overload (FO) are associated with poor outcomes in children receiving extracorporeal membrane oxygenation (ECMO). Our objective is to evaluate the impact of AKI and FO on pediatric patients receiving ECMO for cardiac pathology. METHODS: We performed a secondary analysis of the six-center Kidney Interventions During Extracorporeal Membrane Oxygenation (KIDMO) database, including only children who underwent ECMO for cardiac pathology. AKI was defined using Kidney Disease: Improving Global Outcomes (KDIGO) creatinine criteria. FO was defined as < 10% (FO-) vs. ≥ 10% (FO +) and was evaluated at ECMO initiation, peak during ECMO, and ECMO discontinuation. Primary outcomes were mortality and length of stay (LOS). RESULTS: Data from 191 patients were included. Non-survivors (56%) were more likely to be FO + than survivors at peak ECMO fluid status and ECMO discontinuation. There was a significant interaction between AKI and FO. In the presence of AKI, the adjusted odds of mortality for FO + was 4.79 times greater than FO- (95% CI: 1.52-15.12, p = 0.01). In the presence of FO + , the adjusted odds of mortality for AKI + was 2.7 times higher than AKI- [95%CI: 1.10-6.60; p = 0.03]. Peak FO + was associated with a 55% adjusted relative increase in LOS [95%CI: 1.07-2.26, p = 0.02]. CONCLUSIONS: The association of peak FO + with mortality is present only in the presence of AKI + . Similarly, AKI + is associated with mortality only in the presence of peak FO + . FO + was associated with LOS. Studies targeting fluid management have the potential to improve LOS and mortality outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Utility of cephalic drains in infants receiving extracorporeal membrane oxygenation.

INTRODUCTION: The addition of cephalic drains (CDs) in extracorporeal membrane oxygenation (ECMO) to augment venous drainage may offer benefit, though their use is varied. Our objective was to describe our institution's experience with CDs including flow rates and patency. We also compared complication rates between patients with and without a CD. METHODS: This retrospective cohort study included infants <12 months of age cannulated for ECMO between January 1, 2010 and September 30, 2019 at a single institution. Flow data were obtained for those with a CD. Demographic and complication rates were obtained for all. RESULTS: Of 264 patients in the final cohort, 220 (83%) had a CD of which 93.2% remained patent to decannulation. CDs typically provided 30% or more of ECMO flow throughout the ECMO run. The median time to CD clot was 139 h (range 48-635 h). Patients with a clotted CD had longer ECMO runs than those whose CD remained patent (median 382 h [IQR 217-538] vs 139 h [IQR 91-246], p < 0.001). Survival to discharge was lower for those with clotted versus patent CD (14% vs 70%, p < 0.001). Mechanical complications were more common in patients with CD (p = 0.005). Seizures were more common in those without a CD (p = 0.021). CONCLUSIONS: In this cohort, the majority of CDs placed remained patent at decannulation and provided substantial additional venous drainage. Mechanical problems were common in patients with CDs, but without clinical sequelae. Further study is warranted to elucidate CD impact on short- and long-term outcomes.

Fluid Balance Management Informs Renal Replacement Therapy Use During Pediatric Extracorporeal Membrane Oxygenation: A Survey Report From the Kidney Intervention During Extracorporeal Membrane Oxygenation Group.

Fluid overload (FO) and acute kidney injury (AKI) occur commonly in children supported with extracorporeal membrane oxygenation (ECMO). Continuous renal replacement therapy (CRRT) may be used to manage AKI and FO in children on ECMO. In 2012, our group surveyed ECMO centers to begin to understand the practice patterns around CRRT and ECMO. Since then, more centers are initiating ECMO for increasingly diverse indications and an increased volume of research quantifies the detrimental impacts of AKI and FO. We, therefore, investigated practice patterns of CRRT utilization during ECMO in children. A multi-point survey instrument was distributed to 116 international neonatal and pediatric ECMO centers. Sixty of 116 (51.7%) international neonatal and pediatric ECMO centers responded. All reports using CRRT on ECMO, compared with 75% from the 2012 survey. Eighty-five percent use CRRT to treat or prevent FO, an increased from 59%. The modality of CRRT therapy differed between in-line (slow continuous ultrafiltration, 84.4%) and machine-based (continuous venovenous hemodiafiltration, 87.3%) methods. Most (65%) do not have protocols for fluid management, AKI, or CRRT on ECMO. Trialing off CRRT is dictated by physician preference in 90% (54/60), with varying definitions of success. In this survey study, we found that CRRT use during pediatric ECMO has increased since 2012 with fluid management representing the predominant indication for initiation. Despite the expanded utilization of CRRT with ECMO, there remains significant practice variation in terms of method, modality, indication, the timing of initiation, fluid management, and discontinuation.

Acute Kidney Injury and Fluid Overload in Pediatric Extracorporeal Cardio-Pulmonary Resuscitation: A Multicenter Retrospective Cohort Study.

Acute kidney injury (AKI) and fluid overload (FO) are common complications of extracorporeal membrane oxygenation (ECMO). The purpose of this study was to characterize AKI and FO in children receiving extracorporeal cardiopulmonary resuscitation (eCPR). We performed a multicenter retrospective study of children who received eCPR. AKI was assessed during ECMO and FO defined as <10% [FO-] vs. ≥10% [FO+] evaluated at ECMO initiation and discontinuation. A composite exposure, defined by a four-group discrete phenotypic classification [FO-/AKI-, FO-/AKI+, FO+/AKI-, FO+/AKI+] was also evaluated. Primary outcome was mortality and hospital length of stay (LOS) among survivors. 131 patients (median age 29 days (IQR:9, 242 days); 51% men and 82% with underlying cardiac disease) were included. 45.8% survived hospital discharge. FO+ at ECMO discontinuation, but not AKI was associated with mortality [aOR=2.3; 95% CI: 1.07-4.91]. LOS for FO+ patients was twice as long as FO- patients, irrespective of AKI status [(FO+/AKI+ (60 days; IQR: 49-83) vs. FO-/AKI+ (30 days, IQR: 19-48 days); P = 0.01]. FO+ at ECMO initiation and discontinuation was associated with an adjusted 66% and 50% longer length of stay respectively. Prospective studies that target timing and strategy of fluid management, including its removal in children receiving ECPR are greatly needed.

Extracorporeal membrane oxygenation for COVID-19: evolving outcomes from the international Extracorporeal Life Support Organization Registry.

BACKGROUND: Over the course of the COVID-19 pandemic, the care of patients with COVID-19 has changed and the use of extracorporeal membrane oxygenation (ECMO) has increased. We aimed to examine patient selection, treatments, outcomes, and ECMO centre characteristics over the course of the pandemic to date. METHODS: We retrospectively analysed the Extracorporeal Life Support Organization Registry and COVID-19 Addendum to compare three groups of ECMO-supported patients with COVID-19 (aged ≥16 years). At early-adopting centres-ie, those using ECMO support for COVID-19 throughout 2020-we compared patients who started ECMO on or before May 1, 2020 (group A1), and between May 2 and Dec 31, 2020 (group A2). Late-adopting centres were those that provided ECMO for COVID-19 only after May 1, 2020 (group B). The primary outcome was in-hospital mortality in a time-to-event analysis assessed 90 days after ECMO initiation. A Cox proportional hazards model was fit to compare the patient and centre-level adjusted relative risk of mortality among the groups. FINDINGS: In 2020, 4812 patients with COVID-19 received ECMO across 349 centres within 41 countries. For early-adopting centres, the cumulative incidence of in-hospital mortality 90 days after ECMO initiation was 36·9% (95% CI 34·1-39·7) in patients who started ECMO on or before May 1 (group A1) versus 51·9% (50·0-53·8) after May 1 (group A2); at late-adopting centres (group B), it was 58·9% (55·4-62·3). Relative to patients in group A2, group A1 patients had a lower adjusted relative risk of in-hospital mortality 90 days after ECMO (hazard ratio 0·82 [0·70-0·96]), whereas group B patients had a higher adjusted relative risk (1·42 [1·17-1·73]). INTERPRETATION: Mortality after ECMO for patients with COVID-19 worsened during 2020. These findings inform the role of ECMO in COVID-19 for patients, clinicians, and policy makers. FUNDING: None.

Use of the Selective Cytopheretic Device in Critically Ill Children.

INTRODUCTION: Critically ill children with acute kidney injury (AKI) requiring continuous kidney replacement therapy (CKRT) are at increased risk of death. The selective cytopheretic device (SCD) promotes an immunomodulatory effect when circuit ionized calcium (iCa2+) is maintained at <0.40 mmol/l with regional citrate anticoagulation (RCA). In a randomized trial of adult patients on CRRT, those treated with the SCD maintaining an iCa2+ <0.40 mmol/l had improved survival/dialysis independence. We conducted a US Food and Drug Administration (FDA)-sponsored study to evaluate safety and feasibility of the SCD in 16 critically ill children. METHODS: Four pediatric intensive care units (ICUs) enrolled children with AKI and multiorgan dysfunction receiving CKRT to receive the SCD integrated post-CKRT membrane. RCA was used to achieve a circuit iCa2+ level <0.40 mmol/l. Subjects received SCD treatment for 7 days or CKRT discontinuation, whichever came first. RESULTS: The FDA target enrollment of 16 subjects completed the study from December 2016 to February 2020. Mean age was 12.3 ± 5.1 years, weight was 53.8 ± 28.9 kg, and median Pediatric Risk of Mortality II was 7 (range 2-19). Circuit iCa2+ levels were maintained at <0.40 mmol/l for 90.2% of the SCD therapy time. Median SCD duration was 6 days. Fifteen subjects survived SCD therapy; 12 survived to ICU discharge. All ICU survivors were dialysis independent at 60 days. No SCD-related adverse events (AEs) were reported. CONCLUSION: Our data demonstrate that SCD therapy is feasible and safe in children who require CKRT. Although we cannot make efficacy claims, the 75% survival rate and 100% renal recovery rate observed suggest a possible favorable benefit-to-risk ratio.

Extracorporeal Membrane Oxygenation for COVID-19: Updated 2021 Guidelines from the Extracorporeal Life Support Organization.

DISCLAIMER: This is an updated guideline from the Extracorporeal Life Support Organization (ELSO) for the role of extracorporeal membrane oxygenation (ECMO) for patients with severe cardiopulmonary failure due to coronavirus disease 2019 (COVID-19). The great majority of COVID-19 patients (>90%) requiring ECMO have been supported using venovenous (V-V) ECMO for acute respiratory distress syndrome (ARDS). While COVID-19 ECMO run duration may be longer than in non-COVID-19 ECMO patients, published mortality appears to be similar between the two groups. However, data collection is ongoing, and there is a signal that overall mortality may be increasing. Conventional selection criteria for COVID-19-related ECMO should be used; however, when resources become more constrained during a pandemic, more stringent contraindications should be implemented. Formation of regional ECMO referral networks may facilitate communication, resource sharing, expedited patient referral, and mobile ECMO retrieval. There are no data to suggest deviation from conventional ECMO device or patient management when applying ECMO for COVID-19 patients. Rarely, children may require ECMO support for COVID-19-related ARDS, myocarditis, or multisystem inflammatory syndrome in children (MIS-C); conventional selection criteria and management practices should be the standard. We strongly encourage participation in data submission to investigate the optimal use of ECMO for COVID-19.

Acute Kidney Injury, Fluid Overload, and Renal Replacement Therapy Differ by Underlying Diagnosis in Neonatal Extracorporeal Support and Impact Mortality Disparately.

INTRODUCTION: We aimed to characterize acute kidney injury (AKI), fluid overload (FO), and renal replacement therapy (RRT) utilization by diagnostic categories and examine associations between these complications and mortality by category. METHODS: To test our hypotheses, we conducted a retrospective multicenter, cohort study including 446 neonates (categories: 209 with cardiac disease, 114 with congenital diaphragmatic hernia [CDH], 123 with respiratory disease) requiring extracorporeal membrane oxygenation (ECMO) between January 1, 2007, and December 31, 2011. RESULTS: AKI, FO, and RRT each varied by diagnostic category. AKI and RRT receipt were most common in those neonates with cardiac disease. Subjects with CDH had highest peak %FO (51% vs. 28% cardiac vs. 32% respiratory; p < 0.01). Hospital survival was 55% and varied by diagnostic category (45% cardiac vs. 48% CDH vs. 79% respiratory; p < 0.001). A significant interaction suggested risk of mortality differed by diagnostic category in the presence or absence of AKI. In its absence, diagnosis of CDH (vs. respiratory disease) (OR 3.04, 95% CL 1.14-8.11) independently predicted mortality. In all categories, peak %FO (OR 1.20, 95% CL 1.11-1.30) and RRT receipt (OR 2.12, 95% CL 1.20-3.73) were independently associated with mortality. DISCUSSION/CONCLUSIONS: Physiologically distinct ECMO diagnoses warrant individualized treatment strategies given variable incidence and effects of AKI, FO, and RRT by category on mortality.

Thrombolysis in Children: A Case Report and Review of the Literature.

Thromboembolism (TE), including venous thromboembolism (VTE), arterial TE, arterial ischemic stroke (AIS), and myocardial infarction (MI), is considered a relatively rare complication in the pediatric population. Yet, the incidence is rising, especially in hospitalized children. The vast majority of pediatric TE occurs in the setting of at least one identifiable risk factor. Most recently, acute COVID-19 and multisystem inflammatory syndrome in children (MIS-C) have demonstrated an increased risk for TE development. The mainstay for the management pediatric TE has been anticoagulation. Thrombolytic therapy is employed more frequently in adult patients with ample data supporting its use. The data for thrombolysis in pediatric patients is more limited, but the utilization of this therapy is becoming more commonplace in tertiary care pediatric hospitals. Understanding the data on thrombolysis use in pediatric TE and the involved risks is critical before initiating one of these therapies. In this paper, we present the case of an adolescent male with acute fulminant myocarditis and cardiogenic shock likely secondary to MIS-C requiring extracorporeal life support (ECLS) who developed an extensive thrombus burden that was successfully resolved utilizing four simultaneous catheter-directed thrombolysis (CDT) infusions in addition to a review of the literature on the use of thrombolytic therapy in children.

Extracorporeal Life Support Organization Coronavirus Disease 2019 Interim Guidelines: A Consensus Document from an International Group of Interdisciplinary Extracorporeal Membrane Oxygenation Providers.

Disclaimer: The Extracorporeal Life Support Organization (ELSO) Coronavirus Disease 2019 (COVID-19) Guidelines have been developed to assist existing extracorporeal membrane oxygenation (ECMO) centers to prepare and plan provision of ECMO during the ongoing pandemic. The recommendations have been put together by a team of interdisciplinary ECMO providers from around the world. Recommendations are based on available evidence, existing best practice guidelines, ethical principles, and expert opinion. This is a living document and will be regularly updated when new information becomes available. ELSO is not liable for the accuracy or completeness of the information in this document. These guidelines are not meant to replace sound clinical judgment or specialist consultation but rather to strengthen provision and clinical management of ECMO specifically, in the context of the COVID-19 pandemic.

Planning and provision of ECMO services for severe ARDS during the COVID-19 pandemic and other outbreaks of emerging infectious diseases.

WHO interim guidelines recommend offering extracorporeal membrane oxygenation (ECMO) to eligible patients with acute respiratory distress syndrome (ARDS) related to coronavirus disease 2019 (COVID-19). The number of patients with COVID-19 infection who might develop severe ARDS that is refractory to maximal medical management and require this level of support is currently unknown. Available evidence from similar patient populations suggests that carefully selected patients with severe ARDS who do not benefit from conventional treatment might be successfully supported with venovenous ECMO. The need for ECMO is relatively low and its use is mostly restricted to specialised centres globally. Providing complex therapies such as ECMO during outbreaks of emerging infectious diseases has unique challenges. Careful planning, judicious resource allocation, and training of personnel to provide complex therapeutic interventions while adhering to strict infection control measures are all crucial components of an ECMO action plan. ECMO can be initiated in specialist centres, or patients can receive ECMO during transportation from a centre that is not specialised for this procedure to an expert ECMO centre. Ensuring that systems enable safe and coordinated movement of critically ill patients, staff, and equipment is important to improve ECMO access. ECMO preparedness for the COVID-19 pandemic is important in view of the high transmission rate of the virus and respiratory-related mortality.