Sample-to-Answer Detection of SARS-CoV-2 Viremia Using Thermally Responsive Alkane Partitions.

The diagnosis of bloodborne viral infections (viremia) is currently relegated to central laboratories because of the complex procedures required to detect viruses in blood samples. The development of point-of-care diagnostics for viremia would enable patients to receive a diagnosis and begin treatment immediately instead of waiting days for results. Point-of-care systems for viremia have been limited by the challenges of integrating multiple precise steps into a fully automated (i.e., sample-to-answer), compact, low-cost system. We recently reported the development of thermally responsive alkane partitions (TRAPs), which enable the complete automation of diagnostic assays with complex samples. Here we report the use of TRAPs for the sample-to-answer detection of viruses in blood using a low-cost portable device and easily manufacturable cassettes. Specifically, we demonstrate the detection of SARS-CoV-2 in spiked blood samples, and we show that our system detects viremia in COVID-19 patient samples with good agreement to conventional RT-qPCR. We anticipate that our sample-to-answer system can be used to rapidly diagnose SARS-CoV-2 viremia at the point of care, leading to better health outcomes for patients with severe COVID-19 disease, and that our system can be applied to the diagnosis of other life-threatening bloodborne viral diseases, including Hepatitis C and HIV.

Intra-abdominal Hypertension and Postoperative Kidney Dysfunction in Cardiac Surgery Patients.

OBJECTIVE: To determine the incidence of intra-abdominal hypertension (IAH) in adult cardiac surgery patients and its association with postoperative kidney dysfunction. DESIGN: Prospective cohort study. SETTING: Single tertiary-care university hospital. PARTICIPANTS: Forty-two adult patients having cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Intra-abdominal pressure (IAP) was measured preoperatively, immediately after surgery, and at the following time points after surgery: 3 hours, 6 hours, 12 hours, and 24 hours. Urine neutrophil gelatinase-associated lipocalin (NGAL) levels were measured as a marker of kidney dysfunction at the following time points: prior to surgery, immediately after surgery, 4 to 6 hours after surgery, and 16-to-18 hours after surgery. MEASUREMENTS AND MAIN RESULTS: Two hundred fifty-two IAPs were measured, and 90 (35.7%) showed IAH. Thirty-five of 42 patients (83.3%) had IAH at 1 time point or more. Peak urine NGAL levels were lower in patients with normal IAP (mean difference = -130.6 ng/mL [95% CI = -211.2 to -50.1], p = 0.002). There was no difference in postoperative kidney dysfunction by risk, injury, failure, loss of kidney function, and end-stage kidney disease (RIFLE) criteria in patients with normal IAP (mean difference = -31.4% [95% CI = -48.0 to 6.3], p = 0.09). IAH was 100% sensitive for predicting postoperative kidney dysfunction by RIFLE criteria, but had poor specificity (54.8%). CONCLUSIONS: IAH occurs frequently during the perioperative period in cardiac surgery patients and may be associated with postoperative kidney dysfunction.