Metabolism hypermetabolic states

DNOC exposure results in a hypermetabolic state that resembles heat exhaustion and heat stroke. The basal metabolic rate was increased by 70-100% within 3 days in 2 humans given 3 mg/kg/day DNOC (Dodds and Robertson 1933). Headaches, hyperthermia, profuse sweating, increased pulse rate, and dyspnea are other common signs and symptoms associated with DNOC exposure. In severe cases, tachycardia, delirium, coma, and convulsions are usually observed in humans. An increased basal metabolic rate may, therefore, indicate profound metabolic disturbances. 

During the hyperthyroid state, other drugs that are metabolized by the liver or eliminated renally may need to be adjusted because metabolism may be increased. Patients using drugs with a narrow therapeutic index such as digoxin, warfarin, and phenytoin should be monitored carefully because dosing adjustments will be necessary as the hyperthyroidism or hypermetabolic state resolves. 

A second rare, but potentially fatal, condition associated with acute inhalational anesthetic exposure is malignant hypothermia. This is an autosomal dominant disease in which there is excessive sarcoplasmic release of intracellular Ca " " in skeletal muscles during exposure to inhalational anesthetics. This produces a hypermetabolic state that is manifested as increased muscle rigidity and contracture, tachycardia and metabolic acidosis. Extreme hyperthermia is also present. There are currently a number of worldwide registries for tracking this disease and an ex vivo testing paradigm exists to determine a potentially susceptible persons phenotype. 

Hyperthyroidism is defined as a hypermetabohc condition caused by excessive production of thyroid hormones. This disorder is caused by a number of conditions resulting from excess availability of thyroid hormones (Box 52-3). Some clinicians prefer the general term thyrotoxicosis rather than hyperthyroidism to define the hypermetabolic state associated with increased amounts of thyroid hormone in the circulation. Figure 52-5 depicts the metabolic changes associated with increased avafiability of thyroid hormone. Causes of thyrotoxicosis are divided into two types (1) those associated with frank hyperthyroidism and increased production and secretion of thyroid hormones from the gland, and (2) those that are not. In North America, the most... 

It is evident that variations in thyroid hormone levels are among the main physiological modulators of in vivo cellular oxidative stress. The hypermetabolic state in hyperthyroidism is associated with increases in free radical production and lipid peroxidation (LP), and the hypomet-abolic state in hypothyroidism is generally associated with a decrease in free radical production and LP in most tissues (Fernandez et ai, 1985 Venditti et ai, 1997). The development of a hyperthyroid state in vertebrates leads to enhancement of their basal metabolic rate due to an increase in the rate of O2 consumption in most tissues, excluding the spleen, testis and adult brain (Barker and Klitgaard, 1952). Thyroid hormones were shown... 

K. Herholz and colleagues measured regional cerebral glucose metabolism with PET in patients with anorexia nervosa. During the anorectic state, significant caudate hypermetabolism was found bilaterally (Biol Psychiatry. Jan 1987). 

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