Diuretics

One cannot discuss the management of heart failure without including comments about the kidney. The relationship between the heart and the kidney makes intuitive sense when one considers the importance of the kidney in maintaining an appropriate volume status throughout the body. An analogy that may be useful to consider is the situation in which an individual turns on the faucet at home to find that little water is flowing. The first assumption is that a leak somewhere in the system is responsible for the lower water pressure. An appropriate response is to turn off the water to the house. In an analogous manner, the kidney perceives low cardiac output from a failing heart as a leak. The kidney begins to elaborate hormones designed to retain fluid. Many of the problems in CHF result from an inappro priate neurohumoral activation by the kidney in response to perceived volume depletion from hemorrhage. Mechanisms that result in vasoconstriction are normally compensatory in the short term for acute bleeding. These same adaptive mechanisms become damaging in chronic heart failure.

The usefulness of diuretics in the management of CHF cannot be overstated. Before diuretics were available, rotating tourniquets were used to diminish venous return by ligating the lower extremities. Less venous blood returned to the right side of the heart and pooled in the legs. This procedure diminished the effective in-travascular volume that would otherwise have accumulated in the lungs. The availability of loop diuretics (particularly furosemide) has resulted in the virtual elimination of this practice.

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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