Rapid venous refill time =20 second

Rapid venous refill time =20 seconds is associated with chronic venous disorders, and its measurement in clinical settings as a screening mechanism may provide useful data to augment diagnostic and therapeutic decision making.Future research is needed to establish a best-practice guideline for venous assessment in clinical settings to validate using PPG.Methods:Three hundred and thirty-seven limbs in 169 patients who were high risk for development of deep vein thrombosis were assessed by ultrasonography digital photoplethysmography and the results were compared.Results:Thirteen limbs were found to have deep vein thrombosis as demonstrated by ultrasonography.All limbs with a venous refilling time greater than 12 seconds had a normal ultrasonography.Compared with ultrasonography and using refilling time less than 12 seconds as the cutoff point, digital photoplethysmography achieved a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 73.8%, 13.3%, and 100% respectively, for detecting deep vein thrombosis in asymptomatic high-risk patients.Conclusion:Digital photoplethysmography is a simple, noninvasive, and highly sensitive test for screening of deep vein thrombosis.Objectives:Previous studies evaluating light reflection rheology(LRR)in the preliminary diagnosis of suspected deep vein thrombosis(DVT)have been based on limited patient numbers.The objective of this study was to demonstrate the diagnostic value of LRR in this setting for a large patient series.Methods:A retrospective study was carried out using prospectively collected data over a five-and-a-half year period.During the study period, 3342 limbs were assessed with LLR in 3105 patients referred with suspected DVT(both inpatients and outpatients).Results:In total, 2396(71.7%)of all the LRR tests carried out yielded an abnormal result.Of the remaining 946(28.3%)with a normal result, 204 went on to have a duplex scan due to a high clinical index of suspicion, and 14 DVTs were identified on duplex scanning.Of the remaining 742 patients with a normal LRR result who were not scanned, six re-presented within three months with a confirmed DVT, and one with a confirmed pulmonary embolus(PE).These results yield a negative predictive value of 97.8%, a sensitivity of 96.4% with a three-month post- test thromboembolism incidence of 0.9%.Use of LRR allowed duplex scanning to be avoided for 22.2% of referrals.Conclusions:Despite the increasing use of D-dimers and clinical probability scoring in the preliminary investigation of thromboembolic events, LRR remains a viable alternative in safely risk-stratifying patients with suspected DVT.Background:The value of photoplethysmography(PPG)has been questioned because of a lack of reproducibility.We performed this study to determine whether new digital technology has improved the reproducibility of PPG in the noninvasive assessment of lower limb venous function in patients with isolated superficial venous reflux.Methods:This was a prospective study of 140 legs in 110 patients(65% female; median age[interquartile range], 45 years[36-59.25 years]; CEAP clinical grade C2/3, n=114; C4-6, n=26)who underwent repeated digital PPG measurements of refilling time(RT)in both the sitting and standing position after standard exercise regimens by a single observer.RT was measured in all patients 2 to 5 minutes apart and in a randomly selected subgroup of 30 patients(38 limbs)1 to 2 weeks apart.RT variability was assessed by using Bland and Altman's coefficient of repeatability(CR-RT), where the CR-RT was 1.96 times the standard deviation of the mean difference in RT between two tests.Venous duplex scanning of both the deep and superficial veins was also performed, and a reverse flow of greater than 0.5 seconds was considered abnormal.Only patients with isolated superficial venous reflux were included in the study.Results:The CR-RT of the tests on 140 limbs performed 2 to 5 minutes apart was 10 seconds overall, 3 seconds for RT up to 10 seconds, and 16 seconds for RT between 20 and 40 seconds.The CR-RT of the 38 tests performed 1 to 2 weeks apart was also 10 seconds.No systematic variation due to a nonrandom error was found between the measurements performed either 2 to 5 minutes or 1 to 2 weeks apart.