Healthcare-associated infections: a threat to the survival of patients with COVID-19 in intensive care units.

BACKGROUND: Wide variation in mortality rates among critically ill patients with coronavirus disease 2019 (COVID-19) has been reported. This study evaluated whether healthcare-associated infections (HAI) are a risk factor for death among patients with severe COVID-19 in the intensive care unit (ICU). METHODS: This retrospective cohort study included patients with severe COVID-19 hospitalized in the ICU of four hospitals in the city of Curitiba, Brazil. Patients with COVID-19 who died during ICU hospitalization were compared with those who were discharged. A second analysis compared patients who developed HAI in the ICU with those who did not. Multiple logistic regression models were used to control for confounders. RESULTS: In total, 400 patients were included, and 123 (31%) patients developed HAI. The most common HAI was lower respiratory tract infection (67%). Independent risk factors for death were: age [odds ratio (OR) 1.75, 95% confidence interval (CI) 1.43-2.15; P<0.0001]; clinical severity score (OR 2.21, 95% CI 1.70-2.87; P<0.0001); renal replacement therapy (OR 12.8, 95% CI 5.78-28.6; P<0.0001); and HAI (OR 5.9, 95% CI 3.31-10.5; P<0.0001). A longer interval between symptom onset and hospital admission was protective against death (OR 0.93, 95% CI 0.88-0.98; P=0.017). The only independent factors associated with HAI were high C-reactive protein and low PaO2/FiO2 ratio. CONCLUSIONS: No factors that could point to a high-risk group for HAI acquisition were identified. However, age, dialysis and HAI increased the risk of death in ICU patients with severe COVID-19; of these, HAI is the only preventable risk factor.

Pulmonary tuberculosis associated with the reversed halo sign on high-resolution CT.

We describe the case of a 32-year-old woman with pulmonary tuberculosis in whom a high-resolution CT scan demonstrated the reversed halo sign. The diagnosis of tuberculosis was made by lung biopsy and the detection of acid-fast bacilli in the sputum smear and culture. Follow-up assessment revealed a significant improvement in the lesions.

Monoclonal antibody to an intracellular antigen images human melanoma transplants in nu/nu mice.

Mouse monoclonal antibody TA99 detects a 70-kDa pigmentation-associated glycoprotein in human melanoma cell lines. The antigen cannot be detected on the cell surface by sensitive rosetting techniques or absorption studies, nor can it be detected as a secreted product in culture fluids. Contrary to expectation, 125I-labeled TA99 specifically localized to pigmented human melanoma transplants in nu/nu mice; no localization to nonpigmented melanoma or control tumors was found. Tumor imaging was initially obscured by circulating 125I-labeled TA99 during the first 6 days after antibody injection. With clearance of 125I-labeled TA99 from the blood (half-life, 4-7 days), specific tumor images could be clearly defined by day 13. Due to the persistence of 125I-labeled TA99 at the tumor site (8.9% of the injected dose at 1 week and 4.6% at 8-10 weeks), images were obtainable for up to 10 weeks. At 8-10 weeks, the tumor/blood ratio was 10(4)-10(5), and the tumor/normal tissue ratio ranged from 10(2) to 10(5). In view of these findings, antibodies detecting intracellular antigens may have a role in tumor imaging and therapy.

Clinical evaluation of a new water removal measuring device in standard dialysis.

A new device measuring water removal during standard dialysis is evaluated. The filtrate, collected from a small hemofilter inserted into a normal Cuprophan hollow-fiber dialyzer, was used to evaluate the total water removed from the patient. The device was tested in 46 patients undergoing regular dialysis treatment; the body weight loss ranged from 300 to 5,600 ml for a total of 71 dialysis sessions. Results confirmed the reliability of the device, as the mean prediction error was 5.4%. No influence of the dialyzer blood rest volume on the prediction error was observed. The authors propose this system as an alternative to bed or armchair scales and emphasize its usefulness for experimental purposes.

Lymphoscintigraphic studies of lymphatic drainage from the testes.

Two colloidal radiopharmaceuticals, Au-198 and Tc-99m antimony, were used to evaluate the lymphatic drainage of the testis in experimental animals and humans. One to 24 hours after direct intratesticular injection of Au-198 colloid in dogs and 4-6 hours after injection of Tc-99m antimony colloid in men, distribution within retroperitoneal lymph nodes was demonstrated. Uptake within the para-aortic lymph nodes primarily draining the testis was decreased following proximal ligation of the spermatic vessels in dogs. Testicular lymphoscintigraphy successfully demonstrated an intact spermatic cord lymphatic communication to the para-aortic nodes in five of six patients with chronic lower-extremity lymphedema. When the intact testicle and spermatic cord were transposed to the thigh in a patient with chronic lymphedema of the lower extremity, percutaneous pedal lymphoscintigraphy successfully demonstrated uptake within the para-aortic lymph nodes draining the ipsilateral testis.

Performance of a refrigerated charcoal trap for xenon-133.

The impulse response function of a charcoal trap to a bolus of xenon-133 was determined as a function of the total number of hours run both at room temperature and at 25 degrees C. The peak of the response function for a new trap at room temperature reached a value of 360 MPC at 11 h. After 150 h of operation, the impulse response function was determined at -25 degrees C reaching a value of only 35 MPC at 25 h. The exhaust concentration of a trap in a busy nuclear medicine department using 150 mCi of xenon per week was measured and found to be 1600 MPC. The trap was placed in the freezer and kept there while it continued in use. Over a period of 3 weeks, the concentration of xenon in the exhaust of the trap dropped to a value of 13 MPC, or less than 1% of its value at room temperature.