Journal of clinical monitoring and computing
-
J Clin Monit Comput · Dec 2004
ReviewPulse transit time by R-wave-gated infrared photoplethysmography: review of the literature and personal experience.
Pulse transit time (PTT) is the time it takes a pulse wave to travel between two arterial sites. A rela tively short PTT is observed with high blood pressure (BP), aging, arteriosclerosis and diabetes mellitus. Most methods used for measuring the PTT are cumbersome and expensive. In contrast, the interval between the peak of the R-wave on the electrocardiogram and the onset of the corresponding pulse in the finger pad measured by photoplethysmography can be easily measured. We review herein the literature and impart the experience at our institution on clinical applications of R-wave-gated photo-plethysmography (RWPP) as measurement of PTT. ⋯ In clinical practice, sleep-apnea may be accurately monitored by RWPP. RWPP seems to reflect autonomic influences and may be particularly well-suited for the study of vascular reactivity. Thus, further descriptions of disease-specific cardiovascular reactivity patterns may be possible with techniques based on RWPP. Other clinical uses of RWPP are investigational.
-
J Clin Monit Comput · Dec 2004
Novel hand-held device for exhaled nitric oxide-analysis in research and clinical applications.
Changes in expired nitric oxide (NO) occur in airway inflammation and have proved to be important in the monitoring of inflammatory disease processes such as asthma. We set out to develop a novel hand-held NO-analyzer with a performance comparable to the present more costly and complex chemiluminescence instruments. ⋯ We also show an agreement with the existing 'gold standard' FENO measurement technique, within 0.5 ppb in a group of 19 subjects together with a high linearity and accuracy compared to reference gases. The new analyzer enables affordable monitoring of inflammatory airway diseases in research and routine clinical practice.
-
Information presentation on the monitor screen of ventilator machines affects nurses' response and decision-making during ventilation treatment. The purpose of this study is to evaluate whether a new GUI (graphical user interface) prototype, the so-called circular display prototype can make deviations easy to detect. ⋯ Although the majority of the test subjects preferred the graphical circular display, the results implied that several aspects of this prototype should be improved in a future development study.
-
J Clin Monit Comput · Aug 2004
Clinical TrialPresentation of laboratory and sonoclot variables using principal component analysis: identification of hypo- and hypercoagulation in the HELLP syndrome.
The HELLP (Hemolysis, Elevated Liver enzyme, and Low Platelet) syndrome requires close monitoring of rapid changes in hemostasis. A bedside viscoelastic test--Sonoclot--was used together with coagulation, liver and hemolysis laboratory analyses in three parturients with the HELLP syndrome up to 10 days postpartum. Principal component analysis (PCA) was used to reduce the dimensionality of this multivariate problem and to visualize this process in a two-dimensional plot. ⋯ The effects of emergency delivery, correction of low plasma-antithrombin with plasma and antithrombin factor concentrate, plasma exchange and individualized dosages of low molecular weight heparin to counteract postpartum Sonoclot detected hypercoagulation were evaluated. The efficiency of each treatment strategy was visualized in the PCA plot by movement towards an area with normocoagulation. In conclusion, PCA of viscoelastic and laboratory coagulation analysis data facilitated the detection of both hypo- and hypercoagulative events and represents an alternative way to evaluate treatment strategies in patients with complex coagulative disorders, like the HELLP syndrome.
-
J Clin Monit Comput · Aug 2004
Model-based prediction of expiratory resistance index in patients with asthma.
Develop a sensitive algorithm and index for detection of asthma patients using forced expiratory flow curves. ⋯ The estimated parameters were sensitive indicators of the degree of lung function impairment and were able to accurately distinguish between healthy and asthmatic patients.