Few data are available on the incidence of deep vein thrombosis (DVT) in critically ill COVID-19 with thrombosis prophylaxis. This study retrospectively included 88 patients in the ICU with critically ill COVID-19 at Jinyintan Hospital in Wuhan, China. All patients underwent compression ultrasonography for identifying DVT. Firth logistic regression was used to examine the association of DVT with sex, age, hypoalbuminemia, D-dimer, and SOFA score. The median (interquartile range [IQR]) age and SOFA score of 88 patients were 63 (55-71) years old and 5 (4-6), respectively. Despite all patients receiving guideline-recommended low-molecular-weight heparin (LMWH) thromboprophylaxis, the incidence of DVT was 46% (95% CI 35-56%). Proximal DVT was recognized in 9% (95% CI 3-15%) of the patients, while 46% (95% CI 35-56%) of patients had distal DVT. All of the proximal DVT combined with distal DVT. Risk factors of DVT extension occurred in all distal DVT patients. As Padua score ≥ 4 or IMPROVE score ≥ 2, 53% and 46% of patients had DVT, respectively. Mortality was higher in patients with acute DVT (30%) compared with non-DVT (17%), but did not reach statistical significance. Hypoalbuminemia (odds ratio [OR], 0.17; 95% CI 0.06-0.05, P = 0.001), higher SOFA score (OR per IQR, 2.07; 95% CI 1.38-3.39, P = 0.001), and elevated D-dimer (OR per IQR, 1.04; 95% CI 1.03-1.84, P = 0.029) were significant DVT risk factors in multivariable analyses. High incidence of DVT was identified in patients with critically ill COVID-19, despite the use of guideline-recommended pharmacologic thromboprophylaxis. The presence of hypoalbuminemia, higher SOFA score, and elevated D-dimer were significantly independent risk factors of DVT. More effective VTE prevention and management strategies may need to be addressed. Keywords Deep vein thrombosis • Hypoalbuminemia • D-dimer • SOFA score • Coronavirus Highlights • The incidence of DVT in patients with critically ill COVID-19 was 46% despite the use of guideline-recommended thromboprophylaxis. • The presence of hypoalbuminemia, SOFA score, and elevated D-dimer were predictors of DVT. • More effective VTE prevention strategies are necessary for patients with critically ill COVID-19.
Background: Hospitalized patients with COVID-19 appeared high risk of venous thromboembolism (VTE), which exhibited the predictor of mortality in non-COVID-19 patients. Objectives: We aimed to investigate the association between risk of VTE with 30-day mortality in COVID-19 patients.Methods: In this retrospective cohort study, 1030 consecutive hospitalized patients with COVID-19 were recruited in two hospitals of Wuhan, China. We collected baseline data on demographics, SOFA parameters, and VTE risk assessment models (RAMs) including Padua Prediction Score (PPS), IMPROVE and Caprini RAM. The primary outcome of the study was 30-day mortality. Results: Thirty-day mortality increased progressively from 2% in patients at low risk of VTE to 63% in those at high risk defined by PPS. Similar findings were also observed for risk of VTE defined by IMPROVE and Caprini score. Progressive increases in VTE risk also were associated with higher SOFA score. Our findings showed that the presence of high risk of VTE was independently associated with 30-day mortality regardless of adjusted gender, smoking status and some comorbidities with hazard ratios of 29.19, 37.37, 20.60 for PPS, IMPROVE and Caprini RAM, respectively (P< 0.001 for all comparisons). Predictive accuracy of PPS (AUC, 0.900), IMPROVE (AUC, 0.917) or Caprini RAM (AUC, 0.861) as the risk of 30-day mortality was markedly well.Conclusions: The presence of high risk of VTE identifies a group of patients with COVID-19 at higher risk for 30-day mortality. Furthermore, there is higher accuracy of VTE RAMs to predict 30-day mortality in these patients.
In this Letter, we propose the application of delta-sigma modulation (DSM) higher-order quadrature amplitude modulation (QAM) technology in long-distance transmission of W-band wireless communication, and demonstrate, for the first time to the best of our knowledge, the wireless transmission of millimeter wave signals in the W-band based on 1-bit DSM quantization using polarization-division-multiplexed orthogonal frequency division multiplexing (PDM-OFDM) 1024QAM/4096QAM for 4.6 km. We successfully achieved a bit error rate (BER) of 40-Gbit/s PDM-OFDM 1024QAM and 48-Gbit/s PDM-OFDM 4096QAM after 4.6-km wireless transmission, both lower than the soft decision forward error correction (SD-FEC) of 4.2 × 10−2. To the best of our knowledge, this is the first time that up to 4096QAM signals have been quantized and transmitted based on 1-bit DSM in a 4.6-km-long distance W-band millimeter wave system.
We have proposed and experimentally implemented a photonics-aided large-capacity long-distance mm-wave bidirectional full-duplex communication system at the W-band based on polarization multiplexing. The same radio frequency (RF) carrier source is shared by both the uplink and the downlink, and a pair of orthomode transducers (OMTs) are used to separate the dual orthogonally polarized channels. To achieve the maximum spectrum efficiency and throughput, 10-Gbaud probabilistically shaped 256-level quadrature-amplitude-modulation (PS-256QAM) signals with 7.07 bit/symbol/Hz are transmitted in Ch. H and Ch. V. The system can support the bidirectional transmission with 103-Gbps data rate over 4600-m RF wireless distance. To the best of our knowledge, based on a photonics-aided bidirectional full-duplex system, this is the first time to realize a record-breaking bit rate–distance product at the W-band, i.e., 103 Gbps × 4.6 km = 473.8 Gbps•km.
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