The kidneys are important to many functions, mainly to regulate water fluid levels and to remove waste products from the blood. The kidneys also produce hormones (renin and angiotensin) that regulate how much sodium the body keeps and how well the blood vessels expand and contract thus regulating blood pressure. Healthy kidneys also produce a hormone (erythropoietin – EPO) which stimulates the production of red blood cells. Without this, anemia develops. Another hormone produced by the kidneys is Calcitriol, which is needed to maintain correct levels of calcium, phosphates, and vitamin D. Without these, renal bone disease can develop.
Fluid restrictions are usually necessary when dialysis is initiated, especially if dialysis only occurs three days a week and if urine production is decreased. With tube feedings for in-house dialysis, often there is no fluid other than very minimal flushes given. Build up of fluid can lead to shortness of breath, swelling, and high blood pressure. There is a limit to the amount of fluid that can be safely removed during dialysis. If fluid limits are exceeded and extra water must be removed, negative effects such as muscle cramping, low blood pressure leading to nausea, weakness, dizziness, and possibly extra dialysis sessions to remove the fluid.
Fluid restrictions vary for each individual. Factors in determining the amount of the restriction include weight gain between treatments, urine output, and swelling. Fluids are anything that is liquid at room temperature or melts at room temperature. These include water, tea/coffee, milk, soft drinks, juice, popsicles, ice, ice cream, sherbet, gelatin, soups, liquid creamer, alcohol, water, or beverage used for taking medicine. Some diet manuals include gravy and syrup. You will need to check your facility’s diet manual to see if these are included. The water used to cook certain foods such as rice, pasta, or cereals is not counted unless an individual is very sensitive to liquids due to poor heart or lung function. The same applies for fruits and vegetables that are mainly composed of water, unless someone eats them in very large amounts.
A good way to determine if someone is drinking an appropriate amount of liquid is to look at weight gain between treatments. A weight gain of 1-2 kg is considered appropriate. A larger gain is considered excessive. A liter of fluid weighs about 1 kg. This is also important information when someone drops a significant amount of weight after diuresis (removal of fluid).
Fluid restrictions usually go along with a salt restriction. In long-term care, a No-Added-Salt, or NAS diet is generally adequate. A good control of sodium intake makes fluid restrictions easier to comply. In some cases, a salt restriction may not even be necessary as in cases of in-house dialysis when treatments are given five days a week. The sodium levels in the blood are taken care of with the dialysate (the fluid that is used to clean the blood).
Fluid restrictions are calculated in milliliters (ml) or cubic centimeters (cc) of fluid. 30 ml is approximately 1 oz. A 1500 ml fluid restriction is approximately 50 oz or about 6-1/4 cups. Fluids to be given by dietary are calculated for all meals and snacks. A portion of fluids is reserved and specified for each nursing shift to be given with meds. This calculation should be included in the medication administration record so that nursing knows exactly what dietary is giving and what they have left to give. A copy should be put in the resident’s chart, and a copy for the kitchen staff with the appropriate amounts to be given at meals listed on the resident’s meal ticket/card.
A “Free Water” or “Free Fluid” restriction is a restriction on water only. No water pitcher is left in the room and no water is given on the tray or with meals. All other fluids are not restricted – coffee, juice, tea, etc. may be given without limit. Fluid restrictions are a critical piece in the overall management of the dialysis resident. Nursing, dietary and other ancillary staff need to work together to assure the resident does not exceed their daily fluid restriction.