Diarrhea rehydration therapy

The answer is e. (Hardman, p 926.) Diphenoxylate is a piperidine opioid that is related to meperidine. It inhibits peristalsis and, hence, increases the passage time of the intestinal bolus. It is combined with atropine to discourage use as a street drug. Atropine has little effect on peristalsis. Clonidine, bismuth subsalicylate, and rehydration therapy are all useful in some types of diarrhea, but none of them inhibit peristalsis. 

The movement of Na+ and glucose from the lumen of the intestine across the epithelial cell to the blood sets up a difference in osmotic pressure across the cell. As a result, water flows through the cell, across the apical and basolateral membranes by simple diffusion. Hence the uptake of water requires both Na+ and glucose (or amino acids) to be present in the lumen of the intestine. The presence of water alone in the lumen of the intestine is much less effective. This is the basis of glucose rehydration therapy as a remedy for dehydration a solution of glucose and salt (NaCl) is administered to the patient. This is a simple, inexpensive but extremely important treatment which has saved the lives of many infants in developing countries who would have otherwise died of the effects of dehydration, usually associated with diarrhea. 

Maintenance of the volume of the circulatory system is dependent on sodium ions and water. Oral rehydration therapy may involve drinking a solution of 90 mM NaCl. Replacing K and HCO3 may be a vital concern as well, though they are secondary to water and sodium. Diarrhea can result in acidosis because of the bicarbonate secreted into the lumen and the concomitant delivery of protons to the plasma. Hence, bicarbonate may be included during rehydration therapy to reverse acidosis. Acidosis is defined as a plasma pH less than 7.10. Generally, serious and life-threatening acidosis does not occur with mild or moderate cases of diarrhea. 

Fluid and electrolyte replacement is the cornerstone of therapy. Oral rehydration therapy is preferred in most cases of mild and moderate diarrhea. The necessary components of oral replacement therapy are glucose, sodium, potassium, chloride, and water. 

Appropriate follow-up care of patients with acute diarrhea is based on successful restoration of fluid losses. The clinical signs and symptoms (see Table 111-1) that led to the diagnosis also can indicate adequate rehydration and should be assessed frequently. Because oral rehydration therapy is now preferred, routine laboratory testing often is unnecessary. Electrolytes should be measured in those receiving parenteral fluids, when oral replacement fails, or when signs of hypernatremia or hypokalemia are present. Follow-up stool samples to ensure complete evacuation of the infecting pathogen may be necessary only... 

Oral rehydration therapy (ORT) is a simple and effective way to treat or prevent dehydration and the accompanying electrolyte loss, especially if the dehydration is caused by diarrhea. Oral rehydration therapy was developed in the 1950s for use in developing countries where diarrhea-producing diseases like cholera, combined with unsanitary water and food, cause the death of an estimated 4 million children annually. The threat to children in developed countries is not nearly as great an estimated 500 children die annually from diarrhea in the United States. 

Zinc also has therapeutic benefits for recovery from diarrheal infections. Overall, supplemental zinc provided to children during recovery from either acute or persistent diarrhea leads to a reduction in the duration and severity of the episode. It has been recommended that zinc be used in the management of acute diarrhea, in conjunction with oral rehydration therapy. The current recommendation is to provide 10-20 mg of zinc once daily for 10-14 days. 

Every year, oral rehydration therapy (ORT)—the feeding of an electrolyte solution—saves the lives of countless children worldwide who become severely dehydrated as a result of diarrhea. One requirement of the solution used is that it be isotonic with human blood. 

Lima AA, Carvalho GH, Figueiredo AA, Gi-foni AR, Soares AM, Silva EA, Guerrant RL Effects of an alanyl-glutamine-based oral rehydration and nutrition therapy solution on electrolyte and water absorption in a rat model of secretory diarrhea induced by cholera toxin. Nutrition 2002 18 458-462. 

A 59-year-old obese woman with normal renal function, taking metformin 500 mg tds, took orlistat 120 mg tds for 3 months (147). She developed abdominal pain and diarrhea, for which she was given cimetidine, and became weak and dizzy, with blurred vision, reduced consciousness, agitation, and confusion. Her pH was 6.5, bicarbonate 2 mmol/1, base deficit 38 mmol/1, and lactate 21 mmol/1. She required rehydration, bicarbonate, inotropic support and renal replacement therapy. 

Duggan C, Santosham M, Glass Rl. The management of acute diarrhea in children Oral rehydration, maintenance, and nutritional therapy. MMWR 1992 41 1-20. 

Regardless of the serotypes, the primary goal of therapy is restoration of fluid and electrolyte losses caused by watery diarrhea. ORT is the preferred method of rehydration, and several studies showed reduction in fluid requirements by 32% to 35% when rice-based instead of glucose-based ORT solutions are used (50-80 g rice instead of 20 g glucose per liter). In patients who cannot tolerate ORT, IV Ringer s lactate solution can be used. Normal saline is not recommended because it does not correct metabolic acidosis. After rehydration, maintenance fluid is given based on accurate recording of intake and output volumes. 

An understanding of osmosis and the intestinal absorption of salt and glucose forms the basis for a simple therapy that saves millions of lives each year, particularly in less-developed countries. In these countries, cholera and other intestinal pathogens are major causes of death of young children. A toxin released by the bacteria activates chloride secretion by the intestinal epithelial cells into the lumen water follows osmotlcally, and the resultant massive loss of water causes diarrhea, dehydration, and ultimately death. A cure demands not only killing the bacteria with antibiotics, but also rehydration— replacement of the water that is lost from the blood and other tissues. 

The need for fluid replacement is obvious. Oral rehydration is preferred over intravenous administration of fluids and electrolytes since it is noninvasive. In many third world countries, it is the only therapy available in remote areas. The rehydration formula includes 50-80 g/L rice (or other starch), 3.5 g/L sodium chloride, 2.5 g/L sodium bicarbonate, and 1.5 g/L potassium chloride. Oral rehydration takes advantage of the cotransport of Na and glucose across the cells lining the intestine. Thus, the channel protein brings glucose into the cells, and Na+ is carried along. Movement of these materials into the cells will help alleviate the osmotic imbalance, reduce the diarrhea, and correct the fluid and electrolyte imbalance. 

---