DISCUSSION
The sequela of COVID-19 infection primarily cause a decrease in diffusion capacity and compromised function via obstructive respiratory patterns and weaknesses of accessory muscles [6]. In addition, impairment of cardiac function due to complex mechanisms, an inflammatory immune response from infection, virus invasion of cardiomyocytes, and hypoxic myocardial injury can all occur as complications [7]. A similar pathophysiologic mechanism presumably manifested in this patient.
Many experts in the field believe that it is indispensable to perform respiratory and cardiac rehabilitation treatment simultaneously. However, cardio-pulmonary rehabilitation’s implementation and clinical practice are insufficient and sparse due to the lack of hospital resources and the heightened risks of contagion [3], especially during the current global public health crisis. Moreover, the decline in cardiopulmonary function is a clinical sequela observed as an increasing trend among COVID-19 survivors [9].
The effects of respiratory and cardiac rehabilitation therapies have been proven through various studies to date [8-10]. A recent systematic review showed that respiratory rehabilitation treatment after COVID-19 infection improves respiratory function and quality of life [10]. Since the advent of the current pandemic, CR has been combined with respiratory rehabilitation treatment across centers in many geographic areas. However, no studies show data to confirm its generalizability and substantiate its clinical application as a reliable treatment. The observed clinical result shown in our case study is consistent with the improved effects of CR when combined with respiratory rehabilitation in patients with severe COVID-19 infection following cardiac arrest. Symptoms improved, and bilateral patchy opacity was reduced on chest X-ray findings after acute pharmacologic treatment at 38 days of hospital admission. At this juncture, CR was implemented without concomitant antibiotic therapy. Subsequently, symptoms and radiographic findings were further diminished, and although unaffected by antibiotic treatment, the patient’s decline in function improved following CR application. Nevertheless, the residual symptoms and radiographic opacity persisted.
Hermann et al. (2020) demonstrated in their study of 28 participants following 2-4 weeks of CR in which the group requiring mechanical breathing (n=12) compared to the group without (n=16) showed a significant increase in the measured outcome on 6MWT evaluation [9]. The improvement was shown in VO2/kg, VO2/HR, OUES, and 6MWT, all of which served as indicators of cardiovascular function. In addition, the BBS index by functional balance test also showed improvement.
Aytur, Y et al. (2020) proposed a theory and produced guidelines of respiratory rehabilitation for COVID-19-infected patients through a multi-center trial in Turkey [10]. We followed this model in our study and applied the proposed treatment model in pulmonary rehabilitation. Upon completing the week-long CR treatment, the following respiratory function indicators improved: PFT, FVC, FEV1, PCF, VC, MIC, and MIP/MEP, as shown in Table 1. Simultaneously, cardiovascular function improved which enabled the patient to ambulate independently without difficulty in respiratory function.
CPX results showed improvement in VO2/Kg, VO2/HR, oxygen uptake efficiency slope (OUES), 6MWT, and BBS, as summarized in Table 2. The patient showed functional improvement after a short period of CR by independent ambulation and performance in daily life movements at home without dyspnea and other related respiratory signs and symptoms. As a result, the clinically improved patient successfully returned to community participation.