key: cord-0963940-tijwl81n authors: Gupta, Samir; Batt, Jane; Bourbeau, Jean; Chapman, Kenneth R.; Gershon, Andrea; Granton, John; Hambly, Nathan; Hernandez, Paul; Kolb, Martin; Mehta, Sanjay; Mielniczuk, Lisa; Provencher, Steeve; Stephenson, Anne L.; Swiston, John; Tullis, D. Elizabeth; Vozoris, Nicholas T.; Wald, Joshua; Weatherald, Jason; Bhutani, Mohit title: Triaging Access to Critical Care Resources in Patients with Chronic Respiratory Diseases in the Event of a Major COVID-19Surge: Key highlights from the Canadian Thoracic Society (CTS) Position Statement date: 2020-07-18 journal: Chest DOI: 10.1016/j.chest.2020.07.018 sha: 78dba89b1b65c3729056bc2a8d0b92556c9d062f doc_id: 963940 cord_uid: tijwl81n nan work. JS reports grants and personal fees from Actelion, Johnson & Johnson, Bayer, Unither, and United Therapeutics, outside the submitted work. DET reports grants from Bayer, BI, Celtaxis, Corbus, Proteostasis, Spyryx and Vertex Pharmaceuticals and personal fees from Horizon, Proteostasis, Vertex, outside the submitted work. JWald reports personal fees from GSK, grant from Fisher & Paykel, outside the submitted work. JWeatherald reports grants from CIHR, Lung Association of Alberta and NWT, Heart & Stroke Foundation of Canada, European Respiratory Society, CTS, Canadian Vascular Network; grants and personal fees from Actelion; grants and personal fees from Janssen; personal fees from Novartis and Bayer, outside the submitted work. MB reports personal fees and grants from AZ, BI, GSK, Novartis, Sanofi-Genzyme, CIHR, Alberta Innovates Health Solutions, outside the submitted work. Viral pandemics can quickly overwhelm health system capacity. When a rapid increase in patients with COVID-19 led to intensive care unit (ICU) bed shortages in Northern Italy 1 and elsewhere, clinicians were forced to make difficult ICU resource allocation decisions. Similar surges are now being seen in other parts of the world, including the United States. What frameworks are available to support resource allocation decisions? Ethical frameworks for stewardship of scarce healthcare resources 2 share the common dual aims of saving the most lives and maximizing gains in post-treatment length of life. 3 However, fulfilling these goals requires clinicians to estimate both the patient's probability of surviving the acute illness and life expectancy after the episode of critical illness. These estimations are particularly challenging in patients with underlying chronic respiratory diseases, and practical implementation frameworks are lacking. Recently, several Canadian provinces published frameworks for ICU resource allocation which feature three levels of surge planning 4 . Each surge level provides progressively more strict exclusion criteria for ICU admission (and continued ICU care in those already receiving it), as follows: Level 1-Patients with > 80% expected mortality during or in the 6-12 months following critical illness Level 2-Patients with > 50% expected mortality during or in the 6-12 months following critical illness Level 3-Patients with > 30% expected mortality during or in the 6-12 months following critical illness In order to help clinicians to approximate these predicted mortalities in patients with chronic respiratory diseases, the Canadian Thoracic Society (CTS) produced a position statement describing corresponding characteristics in chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), cystic fibrosis (CF), and pulmonary arterial hypertension (PAH). This commentary summarizes those findings in an FAQ format. The full position statement 5 , including detailed explanations, rationale, and approach for predicting mortalities can be found at https://cts-sct.ca/covid-19/. Disease-based expert groups from across Canada prepared criteria for each respiratory condition independently. Criteria were informed by published survival data, and where possible, complimented by (mostly indirect) data to estimate the impact of critical illness. Accordingly, they are primarily based on expert opinion and should be individualized and supplemented with clinical judgment. Descriptions for each more severe mortality threshold supersede those in the less severe threshold, such that Level 3 descriptions should practically be applied to predict >30 to 50% mortality and Level 2 descriptions to predict >50 to 80% mortality. Which cystic fibrosis patients have > 80% predicted mortality during or in the 6-12 months following critical illness (Level 1)? Patients with FEV 1 of <20% predicted when measured at the time of clinical stability. Which cystic fibrosis patients have > 50% predicted mortality during or in the 6-12 months following critical illness (Level 2)? Patients with FEV 1 of < 20% predicted when measured at the time of clinical stability. Which cystic fibrosis patients have > 30% predicted mortality during or in the 6-12 months following critical illness (Level 3)? Patients with FEV 1 of <30% predicted when measured at the time of clinical stability. Estimates were derived from the Canadian CF Registry, which captures data on >99% of Canadian CF patients. Although FEV 1 of <20% corresponds to a ̴ 50% probability of death/transplant at 1 year (Level 2), this criterion was also recommended for Level 1 given the additional expected mortality impact of the critical illness itself. The Level 3 cut-off was based on the fact that about 30% of Canadian CF patients with FEV 1 of <30% will have died or received a transplant by 2 years. Which pulmonary fibrosis patients have > 80% predicted mortality during or in the 6-12 months following critical illness (Level 1)? Patients with: -FVC <50-60%; OR -DLCO <30-40% predicted; OR -chronic supplemental oxygen use at home for > 12 hours/day); OR -echocardiographic evidence of pulmonary hypertension (estimated right ventricular (RV) systolic pressure >50 mmHg) a ; OR -rapidly progressive disease b ; OR -history of AE-ILD in the last 12 months Patients with: -FVC <50-60%; OR -DLCO <30-40% predicted; OR -chronic supplemental oxygen use at home for > 12 hours/day); OR -echocardiographic evidence of pulmonary hypertension (estimated right ventricular systolic pressure >50 mmHg) a ; OR -rapidly progressive disease b ; OR -history of AE-ILD in the last 12 months Which pulmonary fibrosis patients have > 30% predicted mortality during or in the 6-12 months following critical illness (Level 3)? -FVC <75%; OR -DLCO <55% predicted The GAP (gender, age, physiology) prediction model is the most widely validated prognostic tool used in clinical practice. 6 A ≥10% reduction in FVC over 6-12 months also predicts acute exacerbation, hospitalization, and death. Median survival following acute exacerbation of IPF (AE-IPF) is 3-4 months. 7 Our criteria were derived from literature describing long-term IPF outcomes, predisposing factors and clinical course of AE-IPF, and risk of poor outcomes following surgical lung biopsy. 8, 9 Because we could not identify clear criteria for >50% predicted mortality (Level 2), we reiterated criteria for >80% predicted mortality (Level 1). Level 3 criteria were validated in the GAP model, predicting a relatively low probability of 1-year mortality. 6 Which COPD patients have > 80% predicted mortality during or in the 6-12 months following critical illness (Level 1)? Patients with: -FEV 1 <50% predicted; AND -Chronic hypoxemia (PaO2 55 mmHg); AND -Clinical Frailty Score of >/=7 Which COPD patients have > 50% predicted mortality during or in the 6-12 months following critical illness (Level 2)? Patients with: -FEV 1 <50% predicted; AND -Clinical Frailty Score of >/=6 Patients with: -FEV 1 <50% predicted; AND ->/=2 hospitalizations within the last 12 months for an acute exacerbation of COPD; AND -Clinical Frailty Score of >/=5 We recommend against relying solely on pulmonary function and dyspnea severity (e.g. mMRC) to make triage decisions. COPD patients with documented chronic hypoxemia and hypercapnia have higher 1year mortality 10, 11 . A history of frequent acute exacerbations of COPD is a strong predictor of mortality. 12, 13 The Clinical Frailty Score (CFS) is a validated measure of frailty which has been shown to predict mortality in the year following the ICU admission. 14 Accordingly, we recommend using the CFS to improve prognostication for all surge categories in COPD patients. Which PAH patients have > 80% predicted mortality during or in the 6-12 months following critical illness (Level 1)? Patients with a high-risk profile (REVEAL 2.0 score ≥ 9 or high-risk ESC/ERS score) while on optimal therapy a . Which PAH patients have > 50% predicted mortality during or in the 6-12 months following critical illness (Level 2)? Patients with: -an intermediate risk profile (REVEAL 2.0 score 7-8 or intermediate risk ESC/ERS score) while on optimal therapy; AND -age ≥ 75 years old; AND -either a recent hospitalization for worsening PAH/right heart failure in the past 3 months or the presence of other significant comorbidities (especially chronic renal failure). Patients with: -an intermediate-risk profile (REVEAL 2.0 score 7-8 or Intermediate risk ESC/ERS score) while on optimal therapy; AND -age < 75 years old; AND -either a recent hospitalization for worsening PAH/right heart failure in the past 3 months or the presence of other significant comorbidities (especially chronic renal failure). Poor prognostic factors in PAH include: systemic sclerosis etiology of PAH; older age; male sex; severe symptoms (New York Heart Association Class III-IV); reduced exercise capacity; comorbidities (e.g. renal dysfunction); severe right ventricular dysfunction; and hospitalizations for right heart failure. 15 Available risk prediction tools include the U.S. Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0 risk score 15 and the European Society of Cardiology/European Respiratory Society (ESC/ERS) risk assessment tool. 16 We supplemented mortality predictions from these tools with estimates of the effects of critical illness. Our recommendations apply only to PAH (not to PH groups [2] [3] [4] [5] . Given that the pandemic is a rapidly evolving situation, the CTS plans to update this guidance as new information becomes available. We recommend monitoring the CTS website (https://cts-sct.ca/covid-19/) for updates. Facing Covid-19 in Italy -Ethics, Logistics, and Therapeutics on the Epidemic's Front Line Too Many Patients…A Framework to Guide Statewide Allocation of Scarce Mechanical Ventilation During Disasters Fair Allocation of Scarce Medical Resources in the Time of Covid-19 Government of Ontario. Clinical Triage Protocol for Major Surge in COVID Pandemic Position statement from the Canadian Thoracic Society (CTS) on clinical triage thresholds in respiratory disease patients in the event of a major surge during the Covid-19 pandemic A multidimensional index and staging system for idiopathic pulmonary fibrosis Acute exacerbations of progressive fibrosing interstitial lung disease Evaluation of patients with fibrotic interstitial lung disease: A Canadian Thoracic Society position statement Predictors of mortality poorly predict common measures of disease progression in idiopathic pulmonary fibrosis Predictors of first-year survival in patients with advanced COPD treated using longterm oxygen therapy Hypo-and hypercapnia predict mortality in oxygen-dependent chronic obstructive pulmonary disease: a population-based prospective study Susceptibility to exacerbation in chronic obstructive pulmonary disease Hospitalized exacerbations of COPD: risk factors and outcomes in the ECLIPSE cohort Association between frailty and short-and long-term outcomes among critically ill patients: a multicentre prospective cohort study Predicting Survival in Patients with Pulmonary Arterial Hypertension: The REVEAL Risk Score Calculator 2.0 and Comparison With ESC/ERS-Based Risk Assessment Strategies ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS): Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), International Society for Heart and Lung Transplantation (ISHLT) We acknowledge the Lung Health Foundation for supporting the COPD estimates in this statement. AE -acute exacerbation CFS -clinical frailty score COVID-19 -2019 novel coronavirus CTS -Canadian Thoracic Society DLCO -diffusing capacity of the lungs for carbon monoxide FEV 1 -forced expiratory volume in the first second FVC -forced vital capacity ILD -interstitial lung disease IPF -idiopathic pulmonary fibrosis mMRC -modified Medical Research Council dyspnea scale PaCO2 -partial pressure of carbon dioxide PaO2 -partial pressure of oxygen PH -pulmonary hypertension REVEAL -Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management RV -right ventricular