Spontaneous Evolution of COVID-19 Lung Sequelae: Results from a Double-Step Follow-Up

Background

Few studies have reported a double-step follow-up of patients after hospitalization for COVID-19.

Objectives

We designed an observational double-step follow-up study with a clinical, functional, and radiological evaluation at 2 and 6 months after COVID-19. The primary outcome was to describe symptoms, spirometry, and 6-minute walking test (6MWT) at 2 and 6 months. Secondary outcomes were to identify if the lowest PaO₂/FiO₂ during hospitalization is related with functional and radiological evolution and to assess the correlation between radiological and functional abnormalities at 6 months.

Methods

Symptoms, spirometry, and 6MWT were assessed at 2 and 6 months; arterial blood gas, chest x-ray, and lung ultrasound were performed at 2 months; body plethysmography, diffusing capacity for carbon monoxide (DLCO), and CT scan were performed at 6 months.

Results

Sixty-four per cent and 42% of patients reported at least one symptom at 2 and 6 months, respectively. The most common 6-month functional alteration was DLCO impairment (57% of patients). An improvement of FEV1, FVC, and 6MWT was observed between 2 and 6 months (p < 0.001). Patients with PaO₂/FiO₂ <200 during hospitalization performed worse at 6MWT at 2 and 6 months (p < 0.05) and reported more extended radiological abnormalities at 6 months (p < 0.001) compared with patients with PaO₂/FiO₂>200. At 6 months, more extended radiological abnormalities were related with worse 6MWT, DLCO, and total lung capacity (p < 0.05).

Discussion

DLCO and 6MWT impairment seem to be the functional hallmark of COVID-19 and are related with the severity of acute pneumonia. At 6 months, radiological abnormalities were related to functional impairment.

Pathophysiology of light phenotype SARS-CoV-2 interstitial pneumonia: from histopathological features to clinical presentations

Little is known about the light phenotype of SARS-CoV-2 pneumonia, which behaves in an unusual way, unlike other known respiratory diseases. We believe that the histopathological features of early COVID-19 could be considered the pathophysiological hallmark of this disease. Lung cryobiopsies show almost pristine alveoli, enlarged/hyperplasic alveolar capillaries along with dilatation of the post capillary pulmonary venules. Hypoxemia could therefore be explained by a reduction of the normal V/Q ratio, due to blood overflow around well ventilated alveoli. This could clarify typical manifestations of type L COVID-19, such as happy hypoxemia, response to awake prone positioning, response to PEEP/CPAP and platypnea orthodeoxia.

Noninvasive ventilation and renal replacement therapy in do-not-intubate order critically ill patients: A brief report

INTRODUCTION

Multiple organ failure has been considered a contraindication for noninvasive ventilation (NIV).

MATERIALS AND METHODS

We described the outcome of Do-not-Intubate (DNI) patients with acute respiratory failure, treated with NIV and, subsequently, necessitating renal replacement therapy (RRT).

RESULTS AND DISCUSSION

Seven patients admitted to our Respiratory Intensive Care Unit, developed Acute Kidney Injury (AKI) during NIV treatment and received RRT for 12.8 ± 8 days together with NIV. All the patients but one, discontinued renal support because they regained a satisfactory urinary output; nevertheless mortality rate was high (71%).

CONCLUSION

Our data suggest that RRT could be feasible together with NIV. RRT was associated with an acute improvement in renal function but did not modify the mortality rate.