Biological research for nursing
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Cardiac variability can be assessed from two perspectives: beat-to-beat performance and continuous performance during the cardiac cycle. Linear analysis techniques assess cardiac variability by measuring the physical attributes of a signal, whereas nonlinear techniques evaluate signal dynamics. This study sought to determine if recurrence quantification analysis (RQA), a nonlinear technique, could detect pharmacologically induced autonomic changes in the continuous left ventricular pressure (LVP) and electrographic (EC) signals from an isolated rat heart-a model that theoretically contains no inherent variability. ⋯ These results suggest that when either the sympathetic or parasympathetic division of the autonomic nervous system overwhelms the other, the dynamics underlying cardiac variability become stationary. This study also shows that information concerning inherent variability in the isolated rat heart can be gained via RQA of the continuous cardiac signal. Although speculative, RQA may be a tool for detecting alterations in cardiac variability and evaluating signal dynamics as a nonlinear indicator of cardiac pathology.
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Management of airway inflammation requires proper monitoring and treatment to improve long-term outcomes. However, achieving this goal is difficult, as current methods have limitations. Although nitric oxide (NO) was first identified 200 years ago, its physiological importance was not recognized until the early 1980s. ⋯ Consequently, there is growing interest in the use of exhaled NO in the management of asthma and other pulmonary conditions. The purpose of this review is to promote a basic understanding of the physiologic actions of NO, measurement techniques, and ways that research findings might translate to future application in clinical practice. Specifically, the article will review the role of exhaled NO in regard to its historical background, mechanisms of action, measurement techniques, and implications for clinical practice and research.
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Randomized Controlled Trial Comparative Study
Effects of endotracheal tube suctioning on arterial oxygen tension and heart rate variability.
The purpose of this study was to examine the autonomic mechanisms underlying changes in heart rate (HR) and systolic blood pressure (SBP) responses to endotracheal tube (ETT) suctioning and to compare the open versus closed methods of ETT suctioning on these measures and on arterial oxygen tension. Eighteen orally intubated participants, 33 to 82 years of age (M = 60 years), were randomized for the order of suctioning method. Arterial oxygen tension (PaO2) was measured before suctioning and 30 s and 5 min following suctioning. ⋯ However, there was a decrease in the parasympathetic nervous system indicator of HR variability (HRV) following open suctioning. All patients in this study maintained a PaO2 level 80 mm Hg, which may account for our lack of significant autonomic changes. This suggests that hyperoxygenation with 100% oxygen for a minimum of 1 min (or 20 breaths), as delivered by preoxygenation modes available on most microprocessor ventilators, should be the method of choice for all hyperoxygenation procedures to avoid a decrease in PaO2 following suctioning.
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Comparative Study
A comparison of gastric and rectal CO2 in cardiac surgery patients.
Critical care nurses assess and treat clinical conditions associated with inadequate oxygenation. Changes in regional organ (gut) blood flow are believed to occur in response to a decrease in oxygenation. Although the stomach is a widely accepted monitoring site, there are multiple methodological and measurement issues associated with the gastric environment that limit the accuracy of P CO2 detection. ⋯ Although clinically important, the cause is unclear. Possible explanations include variation in CO2 production between the gastric and rectal site, differences in sensitivity of the two monitoring instruments, or the absence of hemodynamic complications, which limited the extent of change in P CO2. Further investigation using patients with more profound changes in oxygenation are needed to identify response patterns and possible mechanisms.
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More than 24,000 women in the United States are diagnosed with ovarian cancer every year, and half of these women die from their disease. Stage 1 ovarian cancer is curable in 95% of cases; however, due to inadequate screening tools and lack of symptoms in early disease, ovarian cancer is generally at Stage 3 or 4 when finally diagnosed. CA125 is a tumor antigen used to monitor the progression and regression of epithelial ovarian cancer. ⋯ The CA125 molecule is considered a very large glycoprotein because of its molecular weight, and it has three domains: the carboxy terminal domain, the extracellular domain, and the amino terminal domain. MUC16 is the gene that encodes the peptide moiety of the CA125 molecule. MUC16 domains provide novel opportunities to develop new assays and refine current tools to improve the sensitivity and specificity of CA125 for population-based screening guidelines.