In 60% of cases, those who fall ill with covid are still symptomatic 2 months after discharge. The percentage is reduced to 6 months, but still remains high, at 40%. The most frequently reported symptoms are difficulty in breathing, weakness and cough; chest pain, tachycardia, balance disturbances, nausea or low-grade fever follow. This is what emerges from an observational study conducted by the Pneumology and Respiratory Intensive Care of the Irccs Policlinico Sant’Orsola in Bologna, directed by Stefano Nava, recently published in ‘Respiration’.
The study involved 100 patients treated by the Post Covid specialist pulmonary clinic, after a hospitalization occurred during the first Covid wave. The originality of this study – highlighted by Sant’Orsola – is linked to the fact that the same patients were re-evaluated 2 and 6 months after discharge, while most of the follow-up studies available to date in the literature concern only one assessment. Examination, respiratory function tests, 6-minute walk tests (to assess tolerance and saturation under exertion), pulmonary ultrasound and chest X-ray were performed at 2 months. 6 months after discharge, the evaluation also included a high-resolution chest CT, in order to investigate the radiological evolution of Covid-19 pneumonia.
The respiratory function tests – according to the study – identify a significant improvement in lung function from 2 to 6 months, with 86% of patients showing normal spirometry 6 months after discharge. The functional test that is most often altered at 6 months is the alveolar-capillary diffusion of carbon monoxide (Dlco), a test that measures the ability of the alveolus-capillary membrane of the lung to exchange oxygen. This observation is justified by the fact – explain the doctors of Sant’Orsola – that Covid-19 pneumonia, being interstitial pneumonia, affects this pulmonary structure, whose full recovery can take more than 6 months.
The 6-minute walk test shows that patients who have had more severe acute interstitial pneumonia 2 months after discharge walk shorter distances and tend to have greater desaturation under exertion. These data – reads the report – however tend to improve over time, suggesting a progressive recovery of effort tolerance, even in the absence of a standardized rehabilitation program. Radiologically, the majority (64%) of patients present changes in chest x-ray at 2 months after admission; however, comparing the chest CT performed during hospital admission with that performed at 6 months, a progressive reduction in the extent of the disease and in the density of pulmonary consolidations can be noted. Once again, the chest CT scans that show more severe pictures at 6 months are those of the patients who were more severe during hospitalization. Only 26% of Tc at 6 months are completely ‘cleared’: however – the health professionals argue – by its nature, interstitial pneumonia takes a long time to resolve radiologically and, as in all pneumonia, clinical recovery precedes radiological one.
For none of the 100 patients – the researchers conclude – Sars-CoV-2 disease was a simple pneumonia, indeed it created deep wounds, not only of the body, which will leave a perhaps indelible scar. As far as it can count, the possibility of being accompanied, in the recovery after hospitalization, by the staff who treated them during the acute phase, has been for many patients an added value of the clinic, which now follows more than 300.