Predictors and changes of physical activity in idiopathic pulmonary fibrosis.

BACKGROUND: Different clinical predictors of physical activity (PA) have been described in idiopathic pulmonary fibrosis (IPF), but studies are lacking evaluating the potential role of muscle strength and anxiety and depression symptoms in PA limitation. Moreover, little is known about the impact of changes in PA in the course of the disease. The aim of the present study was to investigate the relationship between baseline PA and a wide range of variables in IPF, to assess its longitudinal changes at 12 months and its impact on progression free-survival. METHODS: PA was assessed by accelerometer and physiological, clinical, psychological factors and health-related quality of life were evaluated in subjects with IPF at baseline and at 12 month follow-up. Predictors of PA were determined at baseline, evolution of PA parameters was described and the prognostic role of PA evolution was also established. RESULTS: Forty participants with IPF were included and 22 completed the follow-up. At baseline, subjects performed 5765 (3442) daily steps and spent 64 (44) minutes/day in moderate to vigorous PA. Multivariate regression models showed that at baseline, a lower six-minute walked distance, lower quadriceps strength (QMVC), and a higher depression score in the Hospital Anxiety and Depression scale were associated to lower daily step number. In addition, being in (Gender-Age-Physiology) GAP III stage, having a BMI ≥ 25 kg/m2 and lower QMVC or maximum inspiratory pressure were factors associated with sedentary behaviour. Adjusted for age, gender and forced vital capacity (FVC) (%pred.) a lower progression-free survival was evidenced in those subjects that decreased PA compared to those that maintained, or even increased it, at 12 months [HR 12.1 (95% CI, 1.9-78.8); p = 0.009]. CONCLUSION: Among a wide range of variables, muscle strength and depression symptoms have a predominant role in PA in IPF patients. Daily PA behaviour and its evolution should be considered in IPF clinical assessment and as a potential complementary indicator of disease prognosis.

Absence of relevant clinical effects of SARS-COV-2 on the affinity of hemoglobin for O2 in patients with COVID-19.

Pulmonary involvement in COVID-19 is frequently associated with alterations in oxygenation. The arterial partial pressure of oxygen (PaO2) is the most clinically used variable to assess such oxygenation, since it decisively influences the oxygen transported by hemoglobin (expressed by its percentage of saturation, SaO2). However, two recent studies conducted respectively in silico and using omic techniques in red blood cells of COVID-19 patients have suggested that SARS-CoV-2 could decrease the affinity of oxygen for the hemoglobin (which would imply that PaO2 would overestimate SaO2), and also reduce the amount of this carrier molecule. OBJECTIVE: To evaluate this hypothesis in blood samples from COVID-19 patients. METHODS: Blood gases of all COVID-19 patients performed in our laboratory in two months were included, as well as those from two control groups: synchronous patients with negative PCR for SARS-CoV-2 (SCG) and a historical group (HCG). Both SaO2 and venous saturations (SvO2) measured by cooximetry (COX) were compared separately with those calculated using the Kelman (K), Severinghaus (SV) and Siggaard-Andersen (SA) equations in each group. RESULTS: Measured and calculated SaO2 and SvO2 were practically equivalent in all groups. Intraclass correlation coefficients (ICC) for SaO2 in COVID-19 were 0.993 for COX-K and 0.992 for both COX-SV and COX-SA; being 0.995 for SvO2 for either COX-K, COX-SV or COX-SA. Hemoglobin and ferritin were slightly higher in COVID-19 compared to SCG and HCG (hemoglobin, p < 0.001 for both; ferritin, p < 0.05 for SCG and p < 0.001 for HCG). CONCLUSION: Under clinical conditions SARS-CoV-2 does not have an appreciable influence on the affinity of oxygen for the hemoglobin, nor on the levels of this carrier molecule. Therefore, PaO2 is a good marker of blood oxygenation also in COVID-19.

La afectación pulmonar por COVID-19 se asocia frecuentemente con alteraciones en la oxigenación. La presión parcial arterial de oxígeno (PaO2) es la variable más utilizada clínicamente para valorar dicha oxigenación, ya que influye decisivamente en el oxígeno transportado por la hemoglobina (expresado por porcentaje de saturación, SaO2). Sin embargo, dos estudios recientes realizados respectivamente in silico y mediante técnicas ómicas en hematíes de pacientes han sugerido que SARS-CoV-2 podría disminuir la afinidad del oxígeno por la hemoglobina (lo que implicaría que la PaO2 sobrevaloraría la SaO2 real), e incluso reduciría la cantidad de esta molécula transportadora. OBJETIVO: Evaluar dicha hipótesis en muestras gasométricas de pacientes con COVID-19. MÉTODOS: Se incluyeron las gasometrías de todos los pacientes con COVID-19 realizadas en nuestro laboratorio, así como las de dos grupos control: pacientes sincrónicos con PCR negativa (GCS) y grupo histórico (GCH). Se compararon por separado las SaO2 y saturaciones venosas (SvO2), medidas por cooximetría (COX) con las calculadas mediante las ecuaciones de Kelman (K), Severinghaus (SV) y Siggaard-Andersen (SA) en cada grupo. RESULTADOS: Las cifras de SaO2 y SvO2 medidas y calculadas fueron prácticamente superponibles en todos los grupos. Así, los coeficientes de correlación intraclase (CCI) en COVID-19 para SaO2 fueron 0,993 en COX-K y 0,992 en COX-SV y COX-SA; siendo 0,995 para SvO2 tanto en COX-K como en COX-SV y COX-SA. La hemoglobina y la ferritina resultaron algo superiores en el grupo COVID-19 respecto de GCS y GCH (hemoglobina, p < 0,001 en ambos; ferritina, p < 0,05 para GCS y p < 0,001 para GCH). CONCLUSIONES: En condiciones clínicas, el SARS-CoV-2 no influye de forma apreciable en la afinidad del oxígeno por la hemoglobina, ni tampoco en los niveles de esta última. Por tanto, la PaO2 es un buen marcador de oxigenación sanguínea también en COVID-19.

Absence of Relevant Clinical Effects of SARS-COV-2 on the Affinity of Hemoglobin for O2 in Patients with COVID-19. / Ausencia de efectos clínicos destacables del SARS-CoV-2 sobre la afinidad de la hemoglobina por el O2 en pacientes con COVID-19.

Pulmonary involvement in COVID-19 is frequently associated with alterations in oxygenation. The arterial partial pressure of oxygen (PaO2) is the most clinically used variable to assess such oxygenation, since it decisively influences the oxygen transported by hemoglobin (expressed by its percentage of saturation, SaO2). However, two recent studies conducted respectively in silico and using omic techniques in red blood cells of COVID-19 patients have suggested that SARS-CoV-2 could decrease the affinity of oxygen for the hemoglobin (which would imply that PaO2 would overestimate SaO2), and also reduce the amount of this carrier molecule. OBJECTIVE: To evaluate this hypothesis in blood samples from COVID-19 patients. METHODS: Blood gases of all COVID-19 patients performed in our laboratory in two months were included, as well as those from two control groups: synchronous patients with negative PCR for SARS-CoV-2 (SCG) and a historical group (HCG). Both SaO2 and venous saturations (SvO2) measured by cooximetry (COX) were compared separately with those calculated using the Kelman (K), Severinghaus (SV) and Siggaard-Andersen (SA) equations in each group. RESULTS: Measured and calculated SaO2 and SvO2 were practically equivalent in all groups. Intraclass correlation coefficients (ICC) for SaO2 in COVID-19 were 0.993 for COX-K and 0.992 for both COX-SV and COX-SA; being 0.995 for SvO2 for either COX-K, COX-SV or COX-SA. Hemoglobin and ferritin were slightly higher in COVID-19 compared to SCG and HCG (hemoglobin, p < 0.001 for both; ferritin, p < 0.05 for SCG and p < 0.001 for HCG). CONCLUSION: Under clinical conditions SARS-CoV-2 does not have an appreciable influence on the affinity of oxygen for the hemoglobin, nor on the levels of this carrier molecule. Therefore, PaO2 is a good marker of blood oxygenation also in COVID-19.

Incidence of pulmonary embolism in patients with non-invasive respiratory support during COVID-19 outbreak.

While the incidence of thrombotic complications in critically ill patients is very high, in patients under non-invasive respiratory support (NIS) is still unknown. The specific incidence of thrombotic events in each of the clinical scenarios within the broad spectrum of severity of COVID-19, is not clearly established, and this has not allowed the implementation of thromboprophylaxis or anticoagulation for routine care in COVID-19. Patients admitted in a semi-critical unit treated initially with NIS, especially Continuous-Positive Airway Pressure (CPAP), were included in the study. The cumulative incidence of pulmonary embolism was analyzed and compared between patients with good response to NIS and patients with clinical deterioration that required orotracheal intubation. 93 patients were included and 16% required mechanical ventilation (MV) after the NIS. The crude cumulative incidence of the PE was 14% (95%, CI 8-22) for all group. In patients that required orotracheal intubation and MV, the cumulative incidence was significantly higher [33% (95%, CI 16-58)] compared to patients that continued with non-invasive support [11% (CI 5-18)] (Log-Rank, p = 0.013). Patients that required mechanical ventilation were at higher risk of PE for a HR of 4.3 (95%CI 1.2-16). In conclusion, cumulative incidence of PE is remarkably higher in critically patients with a potential impact in COVID-19 evolution. In this context, patients under NIS are a very high-risk group for developing PE without a clear strategy regarding thromboprophylaxis.

Case Report on a Patient with Steinert Disease Complicated by COVID-19.

SARS-CoV-2 infection is predominantly a respiratory disease with a diverse clinical spectrum. Pulmonary thromboembolic complications during COVID-19 pneumonia may be associated with a high mortality rate and post-mortem findings confirm the presence of platelet-fibrin thrombi in arterial vessels of patients together with lung tissue alterations. We present a patient transferred to the emergency department due to a syncope with no other associated symptoms, who was diagnosed with an acute pulmonary embolism (PE) concomitant with SARS-CoV-2 infection without lung infiltrates. Presenting with a PE as the only manifestation of this infection, reinforces our conception of COVID-19 as a heterogeneous disease of which we still know very little. We believe that while the virus is still circulating in our environment, we need to consider ruling out COVID-19 in all thrombotic events, even if the patients have no other risk factors.

CT imaging of pulmonary embolism in patients with COVID-19 pneumonia: a retrospective analysis.

OBJECTIVES: To describe imaging and laboratory findings of confirmed PE diagnosed in COVID-19 patients and to evaluate the characteristics of COVID-19 patients with clinical PE suspicion. Characteristics of patients with COVID-19 and PE suspicion who required admission to the intensive care unit (ICU) were also analysed. METHODS: A retrospective study from March 18, 2020, until April 11, 2020. Inclusion criteria were patients with suspected PE and positive real-time reverse-transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2. Exclusion criteria were negative or inconclusive RT-PCR and other chest CT indications. CTPA features were evaluated and severity scores, presence, and localisation of PE were reported. D-dimer and IL-6 determinations, ICU admission, and previous antithrombotic treatment were registered. RESULTS: Forty-seven PE suspicions with confirmed COVID-19 underwent CTPA. Sixteen patients were diagnosed with PE with a predominant segmental distribution. Statistically significant differences were found in the highest D-dimer determination in patients with PE and ICU admission regarding elevated IL-6 values. CONCLUSION: PE in COVID-19 patients in our series might predominantly affect segmental arteries and the right lung. Results suggest that the higher the D-dimer concentration, the greater the likelihood of PE. Both assumptions should be assessed in future studies with a larger sample size. KEY POINTS: • On CT pulmonary angiography, pulmonary embolism in COVID-19 patients seems to be predominantly distributed in segmental arteries of the right lung, an assumption that needs to be approached in future research. • Only the highest intraindividual determination of d-dimer from admission to CT scan seems to differentiate patients with pulmonary embolism from patients with a negative CTPA. However, interindividual variability calls for future studies to establish cut-off values in COVID-19 patients. • Further studies with larger sample sizes are needed to determine whether the presence of PE could increase the risk of intensive care unit (ICU) admission in COVID-19 patients.