Two-year diffusion capacity trajectory in COVID-19 pneumonia survivors.

Reduced diffusion capacity (DLCO) after COVID 19 pneumonia was reported in hospitalised patients after discharge. Here, we studied the restoration of DLCO over a 24 months period in COVID-19 pneumonia survivors (n = 317), who were categorised into "moderate" cases (no oxygen supply; no need for hospitalisation), "severe" cases (respiratory frequency > 30/min and/or peripheral oxygen SpO2 < 93%), and "critical" cases (respiratory failure and admission into the intensive care unit). COVID-19 pneumonia survivors with a decreased DLCO (<80%) at 3 months (n = 133) were invited for 6- and 24-months follow-up. At 3 months, impairment of DLCO was more severe in critical case (p < .01). Over time, the subgroups showed a similar level of improvement; and, there was no difference in recovery over time between the subgroups. At 24 months, the DLCO did not differ between the subgroups, with a mean DLCO of 73% for all patients. At 24 months, 65% of patients still had a DLCO < 80%, and in 40% of patients DLCO was <70% of predicted. Regardless the initial disease severity, all COVID-19 survivors showed improvement in DLCO during follow-up; however, DLCO had not normalised in the majority of patients with a DLCO <80% 3 months after hospital discharge.

Pulmonary function and Quality of Life in a prospective cohort of (non-) hospitalized COVID-19 pneumonia survivors up to six months.

OBJECTIVES: A decrease of both diffusion capacity (DLCO) and Quality of Life (QoL) was reported after discharge in hospitalized COVID-19 pneumonia survivors. We studied three and 6 month outcomes in hospitalized and non-hospitalized patients. METHODS: COVID-19 pneumonia survivors (n = 317) were categorized into non-hospitalized "moderate" cases (n = 59), hospitalized "severe" cases (n = 180) and ICU-admitted "critical" cases (n = 39). We studied DLCO and QoL (Short Form SF-36 health survey) 3 and 6 months after discharge. Data were analyzed using (repeated measures) ANOVA, Kruskal-Wallis or Chi-square test (p < .05). RESULTS: At 3 months DLCO was decreased in 44% of moderate-, 56% of severe- and 82% of critical cases (p < .003). Mean DLCO in critical cases (64±14%) was lower compared to severe (76 ± 17%) and moderate (81±15%) cases (p < .001). A total of 159/278 patients had a decreased DLCO (<80%), of whom the DLCO improved after 6 months in 45% (71/159). However the DLCO did not normalize in the majority (89%) of the cases (63 ± 10% vs 68±10%; p < .001). At 3 months, compared to critical cases, moderate cases scored lower on SF-36 domain "general health" (p < .05); both moderate and severe cases scored lower on the domain of "health change" (p < .05). At 6 months, there were no differences in SF-36 between the subgroups. Compared to 3 months, in all groups "physical functioning" improved; in contrast all groups scored significantly lower on "non-physical" SF-36 domains. CONCLUSION: Three months after COVID-19 pneumonia, DLCO was still decreased in the more severely affected patients, with an incomplete recovery after 6 months. At 3 months QoL was impaired. At 6 months, while "physical functioning" improved, a decrease in "non-physical" QoL was observed but did not differ between the moderate and severely affected patients.

Chest computed tomography and alveolar-arterial oxygen gradient as rapid tools to diagnose and triage mildly symptomatic COVID-19 pneumonia patients.

BACKGROUND: In the coronavirus disease 2019 (COVID-19) pandemic, rapid clinical triage is crucial to determine which patients need hospitalisation. We hypothesised that chest computed tomography (CT) and alveolar-arterial oxygen tension ratio (A-a) gradient may be useful to triage these patients, since they reflect the severity of the pneumonia-associated ventilation/perfusion abnormalities. METHODS: A retrospective analysis was performed in 235 consecutive patients suspected for COVID-19. The diagnostic protocol included low-dose chest CT and arterial blood gas analysis. In patients with CT-based COVID-19 pneumonia, the association between "need for hospitalisation" and A-a gradient was investigated by a multivariable logistic regression model. The A-a gradient was tested as a predictor for need for hospitalisation using receiver operating characteristic curve analysis and a logistic regression model. RESULTS: 72 out of 235 patients (mean±sd age 55.5±14.6 years, 40% female) screened by chest CT showed evidence for COVID-19 pneumonia. In these patients, A-a gradient was shown to be a predictor of need for hospitalisation, with an optimal decision level (cut-off) of 36.4 mmHg (95% CI 0.70-0.91, p<0.001). The A-a gradient was shown to be independently associated with need for hospitalisation (OR 1.97 (95% CI 1.23-3.15), p=0.005; A-a gradient per 10 points) from CT severity score (OR 1.13 (95% CI 0.94-1.36), p=0.191), National Early Warning Score (OR 1.19 (95% CI 0.91-1.57), p=0.321) or peripheral oxygen saturation (OR 0.88 (95% CI 0.68-1.14), p=0.345). CONCLUSION: Low-dose chest CT and the A-a gradient may serve as rapid and accurate tools to diagnose COVID-19 pneumonia and to select mildly symptomatic patients in need for hospitalisation.