Estimation of pulse pressure variation and cardiac output in patients having major abdominal surgery: a comparison between a mobile application for snapshot pulse wave analysis and invasive pulse wave analysis

Pulse pressure variation (PPV) and cardiac output (CO) can guide perioperative fluid management. Capstesia (Galenic App, Vitoria-Gasteiz, Spain) is a mobile application for snapshot pulse wave analysis (PWAsnap) and estimates PPV and CO using pulse wave analysis of a snapshot of the arterial blood pressure waveform displayed on any patient monitor. We evaluated the PPV and CO measurement performance of PWAsnap in adults having major abdominal surgery. In a prospective study, we simultaneously measured PPV and CO using PWAsnap installed on a tablet computer (PPV_PWAsnap, CO_PWAsnap) and using invasive internally calibrated pulse wave analysis (ProAQT; Pulsion Medical Systems, Feldkirchen, Germany; PPV_ProAQT, CO_ProAQT). We determined the diagnostic accuracy of PPV_PWAsnap in comparison to PPV_ProAQT according to three predefined PPV categories and by computing Cohen’s kappa coefficient. We compared CO_ProAQT and CO_PWAsnap using Bland-Altman analysis, the percentage error, and four quadrant plot/concordance rate analysis to determine trending ability. We analyzed 190 paired PPV and CO measurements from 38 patients. The overall diagnostic agreement between PPV_PWAsnap and PPV_ProAQT across the three predefined PPV categories was 64.7% with a Cohen’s kappa coefficient of 0.45. The mean (±?standard deviation) of the differences between CO_PWAsnap and CO_ProAQT was 0.6?±?1.3 L min^??1 (95% limits of agreement 3.1 to ??1.9 L min^??1) with a percentage error of 48.7% and a concordance rate of 45.1%. In adults having major abdominal surgery, PPV_PWAsnap moderately agrees with PPV_ProAQT. The absolute and trending agreement between CO_PWAsnap with CO_ProAQT is poor. Technical improvements are needed before PWAsnap can be recommended for hemodynamic monitoring.

     

High-sensitivity C-reactive protein at different stages of atherosclerosis: results of the INVADE study

Evidence on the role of high-sensitivity C-reactive protein (hsCRP) at different stages of atherosclerosis is limited. We therefore analyzed the relationship between hsCRP and measures of subclinical and advanced atherosclerosis in a population-based sample of the INVADE study (n = 3,092, >55 years). The parameters of interest were IMT, ABI, and the stage of atherosclerosis. Differences between participants with normal and pathological hsCRP were analyzed by t test for independent samples or Fishers’ exact test. Differences of hsCRP between IMT quartiles, ABI quartiles, and different stages of atherosclerosis were analyzed by one-way ANOVA. Adjusted stepwise multiple linear regression analysis (IMT and ABI) and adjusted analysis of variance (stage of atherosclerosis) were performed, including significant baseline parameters as covariates. ANOVA showed significant differences of hsCRP among IMT quartiles, ABI quartiles, and patients with and without atherosclerosis. The adjusted analyses confirmed that the effects of IMT, ABI, and atherosclerosis on hsCRP were independent from other significant baseline parameters, but did not yield a significant difference between subclinical and advanced stages of atherosclerosis. The present analysis indicates an independent relationship between hsCRP and both IMT and ABI as measures of subclinical atherosclerosis. The comparison of subclinical and advanced stages of atherosclerosis yielded no significant difference, indicating that hsCRP is sensitive to identify vascular risk patients, but not suited to monitor progression of the disease.     

Modifikation vaskulärer Risikofaktoren durch hausärztliche Intervention

BACKGROUND: The so-called INVADE project examines the efficacy of consistent diagnosis and treatment of cerebrovascular risk factors on the incidence of stroke. METHODS: This analysis compares known cardiovascular risk factors (elevated blood pressure, dipositas, hyperlipidemia, diabetes mellitus, and smoking) and respective medication of 2930 patients with respect to cerebrovascular disease, peripheral arterial disease (PAD), and coronary heart disease (CHD) between baseline and follow-up examination after 2 years of intervention. RESULTS: Using the ankle-brachial index (ABI), 381 patients (13%) with asymptomatic PAD were identified. Comparison between baseline and follow-up examination revealed significant reductions in the following risk factors. Cerebrovascular disease: elevated blood pressure -12.8%, dipositas -4.2%, and LDL -8.1%. For PAD the results were: elevated blood pressure -7.2%, smoking -1.2%, elevated cholesterol -6.4%, dipositas -3.2%, and LDL -7.4%. For CHD the results were: elevated blood pressure -11.3%, elevated cholesterol -13.0%, and LDL -14.9%. CONCLUSION: By the use of ABI, previously undiagnosed asymptomatic PAD was identified in 13% of all patients. Two-year intervention on the primary care level yielded significant reduction of known vascular risk factors.