1. characterized by or causing hyperglycemia.
2. an agent that has this effect.
Hyperosmolality, resulting from the extremely high concentration of sugar in the blood, causes a shift of water from the intracellular fluid (the less concentrated solution) into the blood (the higher concentrated solution). This results in cellular dehydration. Another symptom of HHNK coma, polyuria, occurs because the high plasma osmolality prevents the normal osmotic return of water to the blood by the renal tubules, and it is excreted in the urine. This leads to a decreased blood volume, which severely hampers the kidney’s excretion of glucose and a vicious cycle is begun.
Insulin is administered in small doses, the amount and frequency depending on periodic assessment of blood glucose levels. The objective is to avoid the extremes of hyperglycemia and insulin shock. Intravenous fluids are administered cautiously, so that the sodium and water deficits can be corrected without producing extreme shifts of water from the blood into the intracellular compartment and thus failing to correct the hyperosmolar condition of the blood. Electrolytes other than the sodium lost through diuresis also must be replaced as indicated by laboratory findings.
Patient Care. Fluid volume deficit plays a major role in the development of severe HHNK coma; thus patient care is concerned with careful monitoring of those patients susceptible to its development, especially the elderly, the debilitated, and the mild or unsuspected diabetic. Maintenance of an adequate fluid balance can do much to prevent the hyperosmolar condition and the development of a chain of events that can rapidly lead to coma and death.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.