Q: My dad, 59 years old, is suffering from renal failure. He has dialysis done thrice a week and is allowed to drink only 500 ml water. What happens if he drinks too much of water; is it bad for him? Secondly, I would like to know about foods less in phosphorus. Do guide me on his diet.

A:During kidney failure, the amount of urine produced drops. The urine output usually stops completely once patients have been on dialysis for more than 6 months. Going over your recommended daily fluid allowance can lead to too much fluid build up in your body between treatments. This build up causes swelling over the body, increases blood pressure and would make the heart work harder resulting in heart failure (heart can not pump blood adequately to the body’s other organs resulting in fluid in the lungs). Too much fluid build up in the lungs can make it difficult for the patient to breathe. Fluid restriction may vary for each individual patient on haemodialysis. The recommended daily amount of fluid intake is based on the amount of urine produced in a 24-hour period, amount of weight gained between dialysis treatments, amount of fluid retention as obvious from the swelling, whether the patient has an underlying heart failure and lastly, the level of daily dietary salt intake. Sodium (salt) can cause an increase in blood pressure, water retention, and most important, can make you thirsty. The more you limit your sodium intake, the easier it is to follow your fluid restriction. The commonly prescribed amount of sodium per day for haemodialysis patients is between 1000 and 1200 mg. Your father’s nephrologist would recommend how much fluid he can have by considering the amount of urine he produces each day besides considering the above factors. The less urine he produces, the less fluid he should drink. Most nephrologists will expect haemodialysis patients to limit their daily fluid intake to 1000-1500 ml (33-50 ounces). Following are some of the practical tips for daily fluid restriction: 1. Restrict intake of salty and spicy foods, thereby restricting the sodium intake. 2. Stay cool. Try drinking cold liquids instead of hot beverages and if you are thirsty between meals, try snacking on approved vegetables or fruits that are ice cold 3. Sip your beverages. Sipping will let you savour the liquid longer. Use small cups or glasses for your beverages. 4. Try ice. Many patients find that ice is more satisfying than liquids. However, remember to include the ice you consume when tracking your fluid intake. 5. Take your medicines with your meal, if possible. 6. If you have diabetes, maintain good blood glucose levels. High blood glucose levels will increase your thirst. In patients with kidney failure, there is an elevated blood level of phosphorus, which accumulates, in the soft tissues causing the skin to itch besides resulting in weak and fragile bones. Dialysis treatment does remove some phosphorous in the body though it cannot do it effectively. Hence, dietary control remains vital. The commonly prescribed amount of phosphorous per day for haemodialysis patients is between 500 and 1200 mg. However, practically every food we consume has phosphorous. It is recommended that your father see a nutritionist who can customize a diet plan specific to his needs. Foods high in phosphorus he needs to avoid are most dairy products like milk, cheese, yoghurt, ice cream, milk-based coffee or chocolate drinks, and eggs. Other food articles rich in phosphorous include nuts, corns, dried beans and peas, and processed meat and fish products. Besides, he would also benefit from calcium supplements, which bind the phosphorus in food (phosphate-binders). It is important to take these calcium tablets with meals. The amount of binders that need to be taken by each patient is determined by their blood levels of phosphorus and their intake of phosphorus-containing foods in the diet.