Nutrition
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Calcium is an essential nutrient that is involved in most metabolic processes and the phosphate salts of which provide mechanical rigidity to the bones and teeth, where 99% of the body's calcium resides. The calcium in the skeleton has the additional role of acting as a reserve supply of calcium to meet the body's metabolic needs in states of calcium deficiency. Calcium deficiency is easily induced because of the obligatory losses of calcium via the bowel, kidneys, and skin. ⋯ In older women, the importance of calcium intake is overshadowed by the strong association between vitamin D insufficiency and hip fracture. Whether this insufficiency arises primarily from lack of exposure to sunlight or to a progressive failure to activate the vitamin D precursor in the skin or both is uncertain but it is compounded by a general decline in dietary vitamin D intake with age. The biological effect is probably an impairment of calcium absorption and c
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Review Randomized Controlled Trial Clinical Trial
Outcome of critically ill patients after supplementation with glutamine.
Glutamine has many important metabolic roles that may protect or promote tissue integrity and enhance the immune system. The normal abundance of glutamine has meant that it has not been considered necessary to include glutamine in traditional parenteral feeds. However, low plasma and tissue levels of glutamine (Gln) in the critically ill suggest that demand may exceed endogenous supply. ⋯ The few percent of the most critically ill intensive care patients who are unable to tolerate enteral nutrition are especially at risk since they have increased demands for glutamine yet lack an exogenous supply. Such patients undergo considerable skeletal muscle wasting compromising glutamine supply further. In a prospective, randomised double blind clinical study of 84 patients with a high mortality due to multiple organ failure requiring parenteral feeding a significant improvement in six-month survival was observed in the group supplemented with glutamine 24/42 versus isonitrogenous, isoenergetic control 14/42, P = 0.049.
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Central venous catheter placement for parenteral feeding, whether short-term as in acute hospital care or long-term as in home total parenteral nutrition (TPN), is a well-established intervention in the patient who cannot eat. Access to the central venous system in the majority of the cases is gained by insertion of the catheter into either the subclavian or jugular vein. ⋯ A case report is presented in which a woman developed a venocutaneous fistula due to a chronic indwelling right internal jugular central catheter placed for long-term home nutritional support. The patient's medical history, management of her catheter, and proposed etiology for this problem are discussed, and complications of central access and TPN usage are addressed.
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Review
Hypothalamic neuronal histamine: implications of its homeostatic control of energy metabolism.
In a series of studies on histaminergic functions in the hypothalamus, probes to manipulate activities of histaminergic neuron systems were applied to assess its physiologic and pathophysiologic implications using non-obese normal and Zucker obese rats, an animal model of genetic obesity. Food intake is suppressed by either activation of H1-receptor or inhibition of the H3-receptor in the ventromedial hypothalamus (VMH) or the paraventricular nucleus, each of which is involved in satiety regulation. Histamine neurons in the mesencephalic trigeminal sensory nucleus modulate masticatory functions, particularly eating speed through the mesencephalic trigeminal motor nucleus, and activation of the histamine neurons in the VMH suppress intake volume of feeding at meals. ⋯ Abnormalities produced by depletion of neuronal histamine from the hypothalamus in normal rats mimic those of obese Zuckers. Grafting the lean Zucker fetal hypothalamus into the obese Zucker pups attenuates those abnormalities. These findings indicate that histamine nerve systems in the brain play a crucial role in maintaining homeostatic energy balance.
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The prevention of catheter sepsis lies in a sound understanding of the routes through which catheters get contaminated. The catheter hub has been recognized as a portal for microorganisms causing catheter sepsis, particularly in central venous catheters inserted for > 1 wk. Bacteria and fungi may reach the internal surface of the catheter connector during manipulation by hospital staff and then colonize the entire lumen of the catheter. ⋯ Needleless systems must be evaluated in terms of their safety in preventing endoluminal contamination. A new disinfecting catheter hub incorporating an antiseptic barrier has been developed and reduced hub-related catheter sepsis by more than 90%. The endoluminal route of intravascular catheter contamination must be taken into account when designing strategies for the diagnosis and prevention of catheter-related sepsis.