Journal of clinical monitoring and computing
-
J Clin Monit Comput · Oct 2013
Heart rate variability indices for very short-term (30 beat) analysis. Part 2: validation.
Heart rate variability (HRV) analysis over shorter periods may be useful for monitoring dynamic changes in autonomic nervous system activity where steady-state conditions are not maintained (e.g. during drug administration, or the start or end of exercise). This study undertakes a validation of 70 HRV indices that have previously been identified as possible for short-term use. The indices were validated over 10 × 30 beat windows using PhysioNet databases with physiological states of rest, active, exercising, sleeping, and meditating (N from 12 to 20). ⋯ Spectral indices using the Lomb-Scargle algorithm were able to correctly identify paradoxical shifts in power with meditation and reduced power in exercise. Some less-known indices gave interesting results: PolVar20 identified the higher sympathetic activity of exercise with the largest positive magnitude. These indices should now be considered for rigorous gold standard tests with pharmacological blockade.
-
Esophageal stethoscope is less invasive and easy to handling. And it gives a lot of information. The purpose of this study is to investigate the correlation of blood pressure and heart sound as measured by esophageal stethoscope. ⋯ Heart sounds were analyzed successfully with the esophageal stethoscope through the self-developed program and equipment. A proportional change in heart sounds was confirmed when blood pressure was changed using inotropics or volatile anesthetics. The esophageal stethoscope can achieve the closest proximity to the heart to hear sounds in a non-invasive manner.
-
J Clin Monit Comput · Oct 2013
Intraoperative ICG plasma disappearance rate helps to predict absence of early postoperative complications after orthotopic liver transplantation.
Early postoperative complications after orthotopic liver transplantation (OLT) are a common problem in intensive care medicine. Adequate assessment of initial graft function remains difficult, however, plasma disaperance rate of indocyanine green (PDRICG) may have an additional diagnostic and prognostic value in this setting. We retrospectively evaluated the ability of intraoperative PDRICG values to predict absence of early postoperative complications in 62 subjects. ⋯ The AUROC of serum bilirubin and PT at postoperative day 5 were 0.68 and 0.49, respectively. The optimal cut-off PDRICG value for predicting absence of development early postoperative complications was determined to be 23.5 % min(-1) with 72.4 % sensitivity and 71.0 % specificity. Intraoperative point-of-care PDRICG measurement during OLT already predicts absence of early postoperative complications, better and earlier than clinically used laboratory parameters.
-
J Clin Monit Comput · Oct 2013
Association of intraoperative tissue oxygenation with suspected risk factors for tissue hypoxia.
Tissue hypoxia may cause organ dysfunction, but not much is known about tissue oxygenation in the intraoperative setting. We studied microcirculatory tissue oxygen saturation (StO₂) to determine representative values for anesthetized patients undergoing urological surgery and to test the hypothesis that StO₂ is associated with known perioperative risk factors for morbidity and mortality, conventionally monitored variables, and hypotension requiring norepinephrine. Using near-infrared spectroscopy, we measured StO₂ on the thenar eminence in 160 patients undergoing open urological surgery under general anesthesia (FiO2 0.35-0.4), and calculated its correlations with age, risk level for general perioperative complications and mortality (high if age ≥70 and procedure is radical cystectomy), mean arterial pressure (MAP), hemoglobin concentration (Hb), central venous oxygen saturation (ScvO₂), and norepinephrine use. ⋯ Finally, StO₂ was slightly lower in patients requiring norepinephrine (85 ± 6 vs. 89 ± 6 %, p = 0.001). Intraoperative StO₂ in urological patients was comparable to that of healthy volunteers breathing room air as reported in the literature and correlated with known perioperative risk factors. Further research should investigate its association with outcome and the effect of interventions aimed at optimizing StO₂.