Click here to view next page of this article
Undernutrition is a very common condition in the elderly. About 15% of elderly people eat less than 1000 calories a day and over 30% of poverty stricken elderly people eat over 1000 calories a day. Weight and nutritional status can not be sustained on 1000 calories a day. Institutionalized people are the people at most risk. From one-quarter to two-thirds of nursing home patients being malnourished, undernourished. This was according to the health and nutrition survey. A few points about healthy weights for elderly people. What has been clearly established is that body mass indices that are about 30 pounds overweight are healthier for older folks than ideal body weight. In other words, body mass indices of about 26 to 28 are the healthiest in terms of reduced mortality and this is controlled, adjusted for age and illness and medication use. So it’s just fine that older folks who are about 30 pounds overweight are generally afforded more protection against mortality than other people. These are huge studies. Big actuarial study of 4 million people showed that body mass indices greater than 25 were the best, but you don’t want to get too fat. Most studies show that when you go over 30 - which would be about a 60 pounds overweight - that that’s bad. Except for a study in Finland that was fairly large - had 500 community-dwelling elderly people - that were the oldest of the old. The over 85 population found that they had improved mortality even out malnutrition.
Why are old people at risk for undernutrition? A lot of reasons. One of the reasons is the almost universal deterioration in taste, sight and smell. Some of the pleasurable qualities of eating food. Many of the reasons that we eat is because we enjoy eating. Many older folks eat because they enjoy eating also, but many of them eat because the know they have to eat because they’ll feel bad if they don’t eat. That they must eat. They’ve lost some of the pleasurable or hedonic qualities of eating. Swallowing disorders are common also, especially in dementia and stroke. People can have a lot of trouble getting adequate calories and protein in orally. Dental problems. The most important dental problem is mal-fitting dentures, which is so common. It causes this … it fuels this cycle.
Social causes, such as poverty and alcoholism. Bereavement, particularly for widowers is a big cause of malnutrition in the elderly. Particularly men who have spent their whole life being waited on by their wife. Their wives have prepared all their meals and there are men out there.
Malnutrition is diagnosed by a constellation of clinical and biochemical signs. The most important biochemical marker though is albumin. But there are problems with just albumin that you need to know about. One is that the half-life of albumin is 21 days, therefore changes in a persons nutritional status within the week prior to your seeing them are not reflected in the serum albumin. The other thing that is important is that albumin is sensitive to changes in vascular volume.
Cholesterol. Cholesterol less than 160 is associated with malnutrition. Transferrin less than 200, but this is confounded by iron status. Lymphocytopenia less than 1800 - most people say less than 1500 - is suggestive of malnutrition. Less than 1000 absolute lymphocytes is suggestive of severe malnutrition.
The first type of protein calorie undernutrition I’m going to talk about is kwashiorkor. This is pure protein starvation, wherein albumin is decreased. Calories are often adequate and in fact people are often obese. They are obese because the eat low protein density foods. They eat foods that are high in carbohydrates.
The other type of malnutrition is cachexia, or marasmus type malnutrition characterized by a combined protein and calorie starvation. These people are just not getting enough food. There’s always a history of weight loss and a cachectic appearance. Now an important point is that the body preferentially metabolized skeletal protein before it does visceral protein. And albumin is not skeletal protein. So what the body does, preferentially, is it metabolizes fat stores.
Why do we care about this? Well, for a number of reasons. People who have malnutrition are really at risk for infections and impaired ability to overcome infections. They also have very poor wound healing. They are poor surgical risks. They have great difficulty healing up their decubitus ulcers.
Now what are normal calorie and protein requirements? To make this simple, I think just go with this initial number here over to the left. For maintenance it’s 25 calories per kilogram of ideal body weight per day. For weight gain, you need 30 calories per kilogram of ideal body weight per day.
Some treatment considerations. Some general points: when you approach a malnourished elderly person is first the notion that appetite is linked to nitrogen balance. Sometimes when people get into this anorexic cycle, where they are not eating and they are losing weight, they don’t necessarily have the ability to start eating. I think of it like the Somalian child who is skin and bone. You put a big plate of food in front of them, they can’t eat it. They can’t eat it because they can’t assimilate it. They don’t have the appetite any longer. And sometimes that’s the way it is with elderly folks too. Therefore, once they get into this anorexic cycle of negative nitrogen balance, I think it’s worthwhile to do a trial of tube feeding, if that’s not contraindicated by their advanced directive or whatever. If the goal is to really rehab these folks, sometimes they need trials of tube feeding to really break this anorexic cycle so that they will begin to eat more and more and more on their own and begin to sustain themselves orally. Appetite is linked to GI mucosal nutrient supply. This has been shown. One of the things that causes people to be full, or to have satiety, is to give them a big bolus feeding. However, if you do a drip of 60 cc’s an hour of some tube feeding formula, that tends to stimulate appetite. I think we’ve all experienced this when we were maybe a little bit hungry, not too bad, and then you have a little bite to eat and it causes you to be more hungry. Same sort of thing. So therefore, use continuous drip feedings rather than bolus feedings. You should reach your target by 48 hours. One of the mistakes that our trainees make is they start somebody on a quarter strength Osmolite at 15 cc’s an hour and turn it up the next day, and it could be two months.
Diarrhea. Don’t necessarily stop the tube feeding formula because someone has diarrhea. Use antidiarrheal agents if you can. Use tube feeding products that have fiber. Be aware of clostridium difficile enterocolitis. Treat it, but try not to withhold feedings because somebody has diarrhea. Add Kaopectate to the feedings. There’s a lot of tricks. Avoid using … putting liquid medications in feeding tubes. Liquid medications often have sorbitol as a vehicle to make them sweeter, to make them taste better. Of course that’s a laxative. About five years ago we had a case of refractory diarrhea in the hospital. After multiple scopes and CT’s and everything, we finally figured it out that it was their theophylline that they were getting four times a day via the tube.