Lennard-Jones J E
St. Mark's Hospital, London, England.
Clin Ther. 1990;12 Suppl A:129-37; discussion 138.
Patients with a reduced length of small intestine ending in a stoma experience loss of water and sodium, even when they take nothing by mouth. After food or drink, the loss from the stoma increases. Secretors are patients who lose more from the stoma than they take in by mouth. Absorbers are those whose output is less than their intake. In both groups, the sodium concentration of the effluent is about 90 mmol/L. The secretors are in constant negative sodium balance of up to 400 mmol/day and can only maintain balance with self-administered parenteral water and sodium. The absorbers may lose 200 mmol of sodium daily and need to take an oral sodium supplement to maintain balance. The optimal oral replacement solution has a concentration of at least 90 mmol/L of sodium. Lower sodium concentrations, or drinking water without sodium, lead to increased sodium losses and negative balance. The role of glucose, glucose polymers, or bicarbonate in promoting sodium absorption in the short bowel is unclear. Potassium losses from a small intestinal stoma are small. A modified glucose electrolyte solution, without potassium or bicarbonate and with a sodium concentration of 90 to 120 mmol/L, is appropriate for patients with an intestinal stomal output of 1 to 2 L daily. Once the output rises above 2 L daily, it is difficult to maintain sodium balance with an oral supplement.
小肠长度缩短并以造口结束的患者即使完全禁食也会出现水和钠的流失。进食或饮水后,造口的失水量会增加。分泌型患者造口的失水量超过经口摄入量。吸收型患者则是失水量少于摄入量。两组患者流出液中的钠浓度均约为90 mmol/L。分泌型患者钠平衡持续呈负,每日可达400 mmol,只能通过自行胃肠外补充水和钠来维持平衡。吸收型患者每天可能流失200 mmol钠,需要口服补充钠以维持平衡。最佳口服补液溶液的钠浓度至少为90 mmol/L。钠浓度较低或饮用无钠的水会导致钠流失增加和负平衡。葡萄糖、葡萄糖聚合物或碳酸氢盐在促进短肠钠吸收中的作用尚不清楚。小肠造口的钾流失量很少。一种不含钾或碳酸氢盐、钠浓度为90至120 mmol/L的改良葡萄糖电解质溶液,适用于每日肠造口排出量为1至2升的患者。一旦每日排出量超过2升,通过口服补充剂就很难维持钠平衡。