Table 3. Summary of pulmonary rehabilitation interventions in COVID-19 patients.

Parameters	Summary
Indications!51-551	COVID-19 pneumonia/severe pneumonia with a productive cough but medically stable should participate in PR; asymptomatic and pneumonia with a non-productive cough should do aerobic exercises and home-based exercise program.
Pre-requisites151-531	With the good general condition, no fever/dyspnea/tachypnea, normal SpO2 (>90%), decreased viral load, a FiO2 <0.6, RR <40 breaths/min, PEEP <10 cmH2O (1 cmH2O =0.098 kPa), no airway problems, SBP >90 and < 180 mmHg, MAP >65 and <110 mmHg, HR >40 and <120 beats/min, no arrhythmia, MI, DVT, & PE, high LA (>4 mmol/L), Richmond Agitation-Sedation Scale score: -2 to +2, low IP. Understanding between a physiatrist and other rehabilitation team members is also vital.
What exercises are to do151-53,551 (individualized exercise program designed by a physiatrist in a multidisciplinary facility)	In-patient (without ventilation support but require oxygen therapy) - Exercise includes respiratory (breathing exercise - slow inhalation and exhalation through the nose and mouth respectively, pursed-lip & diaphragmatic breathing) and peripheral muscle training, breathing exercise (intensity - between 1.0 & 3.0 METs, twice/day, duration - from 15 to 45 mins.), (low-intensity exercise (1-3 METs) should be considered initially particularly for patients who required oxygen therapy), bed mobilization, aerobic exercise, joint ROM (active/passive) & stretching, positioning with pillow support (upright, semi-sitting, forward-leaning depending on SOB) thrice/day, bronchial hygiene techniques (assisted cough, postural drainage, and percussion), clearance of secretion (chest maneuvers - cupping & huffing), transfer to and from bed-chair, and NMES of limb muscles. In-patient program for an intubated patient - aerosol-generating PR procedures (cough and huff during treatment), gravity-assisted drainage techniques (prone positioning for over 12 hours in ARDS), open suctions, naso- and oropharyngeal suctioning, sputum inductions, should ideally be performed in a negative pressure room or a closed-door single-room under the guidance of a medical doctor. In-patient program (extubated and before hospital discharge) - Exercise includes respiratory (breathing exercise - slow inhalation through the nose and slowly exhales through the mouth, pursed-lip & diaphragmatic breathing) and peripheral muscle training, breathing exercise (between 1.0 & 3.0 METs those requires oxygen therapy), aerobic exercise, joint ROM & stretching, posture change (upright, semi-sitting, forward-leaning depending on SOB), bronchial hygiene techniques (chest cupping), postural drainage with or without chest percussion), encourage huffing, ADL training, transfer to and from bed-chair, balance training, resume slow-paced ambulation, & NMES for limb muscles. Out-patient program (after discharge from hospital and within a community) - (1) Patient education - using a booklet, videos, telehealth, advise healthy lifestyle education, encourage family and social activities. (2) Respiratory rehabilitation: (i) aerobic exercises (individualized walking, brisk walking, slow jogging, and swimming programs should start with low intensity, for a short duration, 3-5 sessions/week, each session lasts between 20 & 30 min. Intermittent exercise for fatigue. (ii)Muscle strength training (resistance training) - starts with a reduced load, and in target muscle group repeat it 8-12 times, 1-3 sets/time, with 2-min rest between sets, 2-3 sessions/week for 6 weeks. Load increased around 5 to 10% each week; (iii)balance training: hands-free balance training under balance trainer; (iv) breathing exercise (intentional breathing exercise and airway clearance techniques) - breathing exercise: posture management, adjust breathing rhythm, huffing, thoracic expansion training, mobilization of respiratory muscle groups; airway clearance techniques: first, forced expiratory techniques to expel sputum and reduce coughing and energy consumption; second, positive expiratory pressure to assist forced expiration (3) ADL guidance: (i) basic ADLs (rehabilitation for bed mobility, transfer, ambulation, dressing, toileting, and bathing); (ii) instrumental ADLs. Targeted intervention by an occupational therapist would be worth consideration.
Additional supports are required during PR151,52,55,561	Caregiver training, patient counseling (about disease, available treatment, benefit of regular rest, sufficient sleep, smoking avoidance), diet rich with protein, fiber, Vitamin C, and minerals, take adequate fluid, single-use PPE, psychological intervention (where appropriate), long-term oxygen therapy (if required), care for immobility, neurologic evaluation, care for comorbidities (chronic lung-cardiac disease, senility, obesity, and organ failure). Consider ICU-acquired weakness, maintain cough etiquette as well, behavioral modification strategies, and vocation-specific support.
When to do no exercise151-53,551	No major breathing exercise in mild pneumonia, pneumonia without a productive cough, ARDS, or asymptomatic COVID-19. Pulmonary rehabilitation is not recommended for severely ill patients or in those conditions are deteriorating. Avoid manual hyperinflation in patients under ventilation and inspiratory muscle training if infection transmission risk is high.
Monitoring133-35'52-551	Vital signs (before, during, and after exercise) should be documented. Before and after PR, pulse oximetry (SpO2), exercise-induced symptoms (perceived exertion, chest tightness, dizziness, headache, blurred vision, palpitations, and profuse sweating) should also be checked. Evaluation should also include Spirometry (FEV1/FVC), FiO2, and 6-MWT; 1-MWT & 1-STS are useful when patients are being followed-up on teleconsultation. Chest X-ray and CT scanning of COVID-19 unveil lung changes before and after PR.
PR: Pulmonary rehabilitation; RR: Respiratory rate; SpO2: Oxygen saturation; PEEP: Positive end expiratory pressure; SBP: Systolic blood pressure; MAP: Mean arterial pressure; HR: Heart rate; MI: Myocardial infarction; DVT: Deep vein thrombosis; PE: Pulmonary embolism; LA: Lactic acid; IP: Intracranial pressure; METs: Metabolic equivalent; SOB: Shortness of breath; NMES: Neuromuscular electrical stimulation; ARDS: Acute respiratory distress syndrome; ROM: Range-of-motion; ADL: Activities of daily living; PPE: Personal protective equipment; ICU: Intensive care unit; FEV1: Forced expiratory volume in one second; FVC: Forced vital capacity; FiO2: Fraction of inspired oxygen; 1-MWT: 1-Minute walk test; 6-MWT: 6-min walk test; 1-STS: 1-min Sit-to-Stand test; CT: Computed tomography.