Individuals With SARS-CoV-2 Infection During the First and Second Waves in Catalonia, Spain: Retrospective Observational Study Using Daily Updated Data.

BACKGROUND: A description of individuals with SARS-CoV-2 infection comparing the first and second waves could help adapt health services to manage this highly transmissible infection. OBJECTIVE: We aimed to describe the epidemiology of individuals with suspected SARS-CoV-2 infection, and the characteristics of patients with a positive test comparing the first and second waves in Catalonia, Spain. METHODS: This study had 2 stages. First, we analyzed daily updated data on SARS-CoV-2 infection in individuals from Girona (Catalonia). Second, we compared 2 retrospective cohorts of patients with a positive reverse-transcription polymerase chain reaction or rapid antigen test for SARS-CoV-2. The severity of patients with a positive test was defined by their admission to hospital, admission to intermediate respiratory care, admission to the intensive care unit, or death. The first wave was from March 1, 2020, to June 24, 2020, and the second wave was from June 25, 2020, to December 8, 2020. RESULTS: The numbers of tests and cases were lower in the first wave than in the second wave (26,096 tests and 3140 cases in the first wave versus 140,332 tests and 11,800 cases in the second wave), but the percentage of positive results was higher in the first wave than in the second wave (12.0% versus 8.4%). Among individuals with a positive diagnostic test, 818 needed hospitalization in the first wave and 680 in the second; however, the percentage of hospitalized individuals was higher in the first wave than in the second wave (26.1% versus 5.8%). The group that was not admitted to hospital included older people and those with a higher percentage of comorbidities in the first wave, whereas the characteristics of the groups admitted to hospital were more alike. CONCLUSIONS: Screening systems for SARS-CoV-2 infection were scarce during the first wave, but were more adequate during the second wave, reflecting the usefulness of surveillance systems to detect a high number of asymptomatic infected individuals and their contacts, to help control this pandemic. The characteristics of individuals with SARS-CoV-2 infection in the first and second waves differed substantially; individuals in the first wave were older and had a worse health condition.

[Influence of the method used to obtain pleural fluid on the determination of the Acid-base balance]. / Importancia de la forma de obtención del líquido en la determinación del equilibrio ácido-base pleural.

OBJECTIVE: To analyze the methods used in our hospital for obtaining pleural fluid to determine the acid-base balance and to evaluate the clinical repercussions of each method. METHODS: Initially we studied the methods used by physicians in our hospital to collect pleural fluid for determination of the acid-base balance. In a second phase, we performed a prospective, descriptive, comparative study with the participation of 71 patients with pleural effusions in order to compare the acid-base balance according to the technique used to obtain the fluid. RESULTS: Pleural fluid was obtained using 3 methods: a) direct extraction using a heparinized syringe (group 1); b) extraction using a 20 mL syringe with subsequent aspiration from this syringe into a heparinized syringe (group 2); and c) filling a heparinized syringe from the 20 mL syringe (group 3). The only significant differences between group 1 and groups 2 and 3 were an increase in the pleural PO2 and oxygen saturation. The difference in the mean pH between groups 1 and 2 was 0.009 (95% confidence interval: -0.39 to 0.02; P=.5) and between groups 1 and 3 was 0.007 (95% confidence interval: -0.38 to 0.023; P=.6). The correlations between findings for PO2, pH, and PCO2 obtained in the different groups were statistically significant, with values superior to .95 in the last 2 variables. CONCLUSIONS: Physicians who perform thoracentesis in our hospital use different methods for obtaining fluid to determine the pleural acid-base balance. The 3 methods analyzed show no significant differences with regard to pH or PCO2. Pleural fluid may be obtained by a single puncture with a large-volume syringe, subsequently transferring the fluid to a heparinized syringe without this significantly affecting the pH or PCO2, thus reducing the number of manipulations and the risk of complications.

[Utility of amylase levels in malignant pleural effusions]. / Importancia de la determinación de la amilasa pleural en los pacientes con derrame neoplásico.

BACKGROUND AND OBJECTIVE: To analyze the utility of the measurement of pleural amylase levels (AL) and pleural fluid/serum amylase ratio (AR) in malignant pleural effusions. PATIENTS AND METHOD: Prospective and comparative study of AL and its AR in relation to the patient and pleural fluid characteristics in 295 malignant effusions and 673 nonmalignant. RESULTS: There were 103 patients with AL greater than 100 U/l (11%) and 268 with AR greater than 1 (28%): 53 (18%) and 109 (37%) in malignant effusions respectively. Patients with malignant effusions had higher AL and AR, especially when tumour origin was lung cancer, had positive pleural citology or biopsy and showed an adenocarcinoma. Multivariate regression analysis revealed a significant difference in the changes in AL associated with positive pleural citology or biopsy and massive pleural effusion. The malignant effusions had higher AL in lung cancer of stage IV. CONCLUSIONS: AL and AR should not be routinely measured to exclude a malignant effusion. A high AL or AR was related to positive pleural citology or biopsy, a massive pleural effusion and lung cancer with an advanced disease.