The slip extrusion test: A novel method to characterise bolus properties.

The role of mastication is to prepare a bolus for safe swallowing. The Swallow Safe model defines deformability, slippiness, and cohesiveness as key properties that influence whether a bolus is safe to swallow. Defining these properties numerically is difficult and current instruments used for bolus analysis have limitations. The slip extrusion test (SET) was developed to objectively measure the swallowability of the bolus through determination of its resistance to deformation and slip. The test measures the force needed to extrude a bolus through a bag as it is pulled through a pair of rollers, imitating the swallowing action of a bolus. Three food model systems were used to evaluate the SET: (a) viscous solutions with varying viscosity, (b) gels with varying hardness, and (c) particulate systems of varying cohesion. The test was applied to peanut boluses produced in vivo to demonstrate its potential in characterizing boluses. The deformation and slip resistance measurements correlated well with the hardness and viscosity measurements of the gels and viscous solutions respectively (correlation coefficient r = .94 between deformation resistance and hardness; r = .85 for slip resistance and hardness in gels; r = .98 for deformation resistance and viscosity; r = .93 for slip resistance and viscosity in solutions). The advantage of the SET is it can evaluate the swallowability of a wide range of foods of different structure and composition. It could potentially be used to investigate the properties of boluses throughout oral processing and help in establishing the criteria for a safe to swallow bolus in a quantitative way. PRACTICAL APPLICATIONS: The test could be used to measure bolus properties from the initial stages of breakdown to the point of swallow for all types of food. The ability to measure the changes in bolus properties through all stages of breakdown using the same instrument is a significant development. The resistance to deformation and slip are quantitative measurements that could potentially be used to further develop the Swallow Safe model by providing numerical limits to the identified properties. This could be of interest to the development of foods for dysphagia sufferers.

Influence of psychosocial factors and biopsychosocial interventions on outcomes after myocardial infarction.

Management of the myocardial infarction patient may extend beyond the physiologic to include psychosocial factors that may adversely affect cardiac health. Psychosocial factors such as depression, coronary-prone behavior, hostility, social isolation, anxiety, anger, and stress are related to increased cardiac death and illness. Various interventions including cognitive-behavioral therapies, techniques that elicit the relaxation response, meditation, exercise, and increasing social networks, may play a role in improving health outcomes. This article explores the relationship of these psychosocial factors to cardiac health and proposes a biopsychosocial model of care.

The mind-body connection: the psychophysiology of many traditional nursing interventions.

The bidirectional relationship between mind and body and the concept that psychological processes can produce attendant physiologic changes are explored in this article. The mind-body connection provides a framework for exploring a psychophysiologic explanation for the therapeutic properties of some traditional nursing interventions to potentiate health and healing. This model allows nurses to move from tradition-based practice to knowledge-based practice. CNSs provide direct patient care, consult with staff nurses, influence systems of care, and engage in outcome research. This mind-body paradigm provides a model for practice and a framework for quantifying outcomes.

Psychophysiologic control mechanisms in ischemic heart disease: the mind-heart connection.

The cardiovascular system is a unified, dynamic, constantly responding system. Adjustments are made in response to local metabolic factors, systemic physiologic factors, or peripheral and central nervous system factors. This article focuses on the interactions of the cardiovascular system with the peripheral and central nervous system. Since activation of the sympathetic branch of the autonomic nervous system appears to play an important role in cardiovascular physiology and pathophysiology, a more detailed description of this system appears. Using Engel's Biopsychosocial Model of Health and Disease, the impact of the mind and emotions on cardiovascular behavior and health is emphasized. Several key nursing interventions that have been shown to impact favorably on mind-heart interactions are highlighted.

The efficacy of the relaxation response in preparing for cardiac surgery.

This study evaluated the efficacy of the relaxation response on the post-operative recovery of 27 cardiac surgery patients randomly assigned to one of two groups. Thirteen experimental group patients received educational information and practiced eliciting the relaxation response before and after surgery. The 14 patients in the control group received only information. Experimental and control groups were compared before and after surgery on both physiological and psychological recovery variables. There were no initial differences between experimental and control groups on demographic, physiological, and most psychological variables. The experimental group had lower incidence of postoperative supraventricular tachycardia (SVT) than the control group (p = .04) despite having had the same occurrence previously. Experimental and control groups did not significantly differ over the course of study on any other physiological variables. Patients practicing the relaxation response had greater decreases in psychological tension (p = .04) and anger (p = .04) than those who received only educational information. The decreases in psychological tension may have been a result of regression to the mean because the experimental group started with elevated tension relative to the control group (p = .04). We conclude that practicing the relaxation response before and after surgery may reduce SVT, tension, and anger.