Transcript Lecture 7b powerpoint

Lecture 7b
Chapter 20 Dudek
Hypertension, Stroke and Congestive
Heart Failure
Hypertension
• A symptom, not a disease
• Arbitrarily defined as sustained elevated blood
pressure greater than or equal to 140/90 mm
Hg in otherwise healthy persons (130/85 mm
Hg in diabetics)
• A major risk factor for heart disease, stroke,
kidney failure, congestive heart failure, and
peripheral arterial disease
• One of the most common chronic conditions in
the Canada
Hypertension—how does it arise?
Hypertension—(cont.)
• Compared to nonblacks, blacks
– Have a higher prevalence of hypertension
– Develop hypertension earlier in life
– Have higher risks of hypertension-related
complications such as
o Especially stroke
o Kidney failure
Hypertension—(cont.)
• Dietary factors play a prominent role in blood
pressure regulation.
• Normotensive or prehypertensive
– Dietary changes have the potential to reduce
blood pressure and prevent hypertension
and its complications.
Hypertension—(cont.)
• Stage 1 hypertension
– Diet is the initial treatment before drug
therapy is introduced and may eliminate the
need for medication.
• For those who have hypertension who are
treated with medication
– Diet can lower blood pressure and reduce the
dose of medication needed.
Hypertension—(cont.)
• The DASH Diet
– DASH = Dietary Approaches to Stop
Hypertension
– Multicenter feeding study
– Eating whole “real” foods rather than
individual nutrients
– Significantly lowers both systolic and diastolic
blood pressures as well as cholesterol
Hypertension—(cont.) The DASH eating plan
DASH Food Groups
DASH Daily Servings
(except as noted)
DASH Serving Sizes
Vegetables
4-5
250 mL (1 cup) raw leafy vegetables
125 mL (½ cup) cooked vegetables
170 ml (6 oz) juice
Fruit
4-5
1 medium piece of fruit
63 mL (¼ cup) dried fruit
125 mL (½ cup) fresh, frozen or canned fruit
Grains
(mainly whole grains)
7-8
1 slice bread
250 mL (1 cup) ready to eat cereal
125 mL (½ cup) cooked rice, pasta or cereal
Low Fat or No-Fat Dairy Foods
2-3
250 mL (1 cup) milk
250 ml (1 cup) yogurt
50 g (1½ oz) cheese
Lean meats, poultry and fish
2 or less
3 ounces cooked lean meats, skinless poultry,
or fish
Nuts, seeds and dry beans
4-5 per week
1/3 cup (1.5 oz.) nuts
30 mL (2 tbsp) peanut butter
2 tbsp (1/2 oz.) seeds
1/2 cup cooked dry beans or peas
Fats and Oils
2-3
5 ml (1 tsp) soft margarine
15mL (1 tbsp) low-fat mayonnaise
30 mL (2 tbsp) light salad dressing
5 ml (1 tsp) vegetable oil
Hypertension—(cont.) The DASH eating plan
Hypertension—(cont.)
• The DASH Diet—(cont.)
– DASH-sodium
o Lowering sodium lowers blood pressure.
o Greatest reduction in blood pressure
occurred at 1500 mg of sodium.
o Greatest blood pressure reductions
occurred in blacks; middle-aged and older
people; and in people with hypertension,
diabetes, or chronic kidney disease.
Hypertension—(cont.)
• DASH diet is very similar to Canada’s food guide
Hypertension—(cont.)-good diet and
exercise can lead to weight loss
• Weight loss
– Observational and clinical studies consistently
show
o Weight is directly related to blood pressure.
o Weight loss lowers blood pressure, even if
healthy weight is not attained.
– The greater the weight loss, the greater the
reduction in blood pressure.
Hypertension—(cont.)
• Weight loss—(cont.)
– Achieving a healthy weight (BMI
<25)/waist circumference is an effective
intervention to prevent and treat
hypertension.
– Preventing weight gain is critical.
• Potassium-found in a good diet
– Potassium intake increases, blood pressure
decreases.
– Recommended that people consume 4.7 g
potassium per day-leads to drop in blood
pressure
Hypertension and diet (cont.)
• Alcohol
– Observational studies and clinical trials
o Show a direct, dose-dependent
relationship between alcohol and blood
pressure
o Alcohol intake should be limited to 2
drinks or less per day in men and 1
drink or less per day for women.
Stroke
Stroke due to atherosclerotic process and hypertension
There are 3 types of stroke:
• Thrombotic
• Embolic
• Haemorrhagic
Dietary recommendations pre- and post-onset as in lecture
7a and 7b
Congestive Heart Failure (HF)
• Chapter 20
Congestive Heart Failure (CHF)
• The problem-blood returning to heart cannot be
pumped out as fast as it arrives so blood (and the water
portion of blood) backs up
• Syndrome characterized by specific symptoms
– Shortness of breath-flooding of lungs
– Fatigue-poor gas exchange
– Oedema-water backing up
• Coronary atherosclerotic heart disease (CHD) causing
heart attack (myocardial infarction), hypertension, and
diabetes are prevalent causes; arrhythmias and valve
disorders may also cause CHF.
Congestive Heart Failure-Pathology
Myocardial infarction can lead to chronic or
congestive heart failure
-weakened heart can not keep up with water
load returning to heart and fluid backs up in
the extremities and in lungs
-heart becomes even more weakened because
it tries to pump more fluid but struggles to do
so
-ultimately the heart is overwhelmed by the
fluid load and quits
Congestive Heart Failure (CHF)
Type of heart failure
Description
Left-sided heart failure
Fluid may back up in your lungs,
causing shortness of breath.
Right-sided heart failure
Fluid may back up into your
abdomen, legs and feet, causing
swelling.
Systolic heart failure
The left ventricle can't contract
vigorously, indicating a pumping
problem.
Diastolic heart failure
(also called heart failure with
preserved ejection fraction)
The left ventricle can't relax or fill
fully, indicating a filling problem.
Congestive Heart Failure (HF)-one
characteristic is oedema
Treatment of CHF
-treatment consists of diuretics (reduce fluid
load) and glycosides (strengthen cardiac
intropy)
-with this combination strong chance of
potassium deficiency (why?) and constipation
-constipation can stress heart
CHF and Nutrition status
-build up of fluid causes heart and lungs to work
harder
-when the heart and lungs work harder they
require more energy
-yet that extra energy is not available because fluid
build up impairs cardiac and pulmonary function
CHF and Nutrition status
- since blood flow and oxygen delivery are
critical to the processes of digestion,
absorption and transport and energy release
the extra energy required for the heart and
lungs is not there
- therefore heart and lungs cannot keep up
and there is heart failure and ultimately
flooding of the lungs
-all above limits energy and protein intake
CHF and Nutrition status
-oral intake may be limited by anorexia, taste
sensitivity, intolerance to food odours,
physical exhaustion, low sodium diet
-weight loss may go unnoticed due to oedema
since oedema masks weight loss
-consequently PEM can occur – in this case
PEM is called cardiac cachexia
Congestive Heart Failure (HF)—(cont.)
• Nutrition therapy—(cont.)
– Cardiac cachexia
o Need a high-calorie, high-protein, highnutrient diet while maintaining a lowsodium diet
o Caloric and nutrient density are
important.
Congestive Heart Failure (CHF)—(cont.)
• Nutrition therapy
– For people at risk of CHF, the goals of
therapy are to control underlying risks.
– DASH-sodium diet is appropriate for people
with CHD or hypertension.
– Regular exercise and smoking cessation are
encouraged.
– Alcohol is discouraged.
Congestive Heart Failure (CHF)—(cont.)
• Nutrition therapy—(cont.)
– Stage C congestive heart failure is defined as
structural heart disease with prior or current
symptoms of CHF.
o Sodium is limited to 2 g of sodium/day or less.
o A fluid restriction of 1.5 L/day for patients with
hyponatremia
o A low-calorie diet for patients who are overweight
o Small, frequent meals
o Soft, easy-to-chew foods for patients with fatigue
o Increased potassium intake for patients who are
taking thiazide (potassium-wasting) diuretics or
digitalis
Nutrition therapy for CHF
-increase potassium by eating potassium rich
foods if potassium deficient
-aim is to improve nutrition status and to
reduce cardiac work (losing weight reduces
cardiac work)
Nutrition therapy for CHF
-reduce fluid and sodium intake- remember
body in CHF is having trouble keeping up
with the water load
-sodium increases the water load and
ultimately the blood pressure
Nutrition therapy for CHF
reduce fluid and sodium intake- remember body in
CHF is having trouble keeping up with the water
load
-as blood pressure increases the risk of kidney
failure increases
-if kidney failure occurs then fluid retention
will shut down the body
-dialysis is an option but not nearly as
good as properly functioning kidneys
Nutrition therapy for CHF
reduce fluid and sodium intake- remember body in
CHF is having trouble keeping up with the water
load
-patient gets high nutrient density foods-get
energy and protein with less fluid
-heart healthy diet described previously this
week is appropriate to ensure that there is a
reduced risk of heart attack or subsequent
heart attack
Nutrition therapy for CHF
-a healthier heart is critical to being able to meet
the demands of increased water load
-max 2000 mg sodium per day
-if recurrent or persistent fluid retention then no
more than 2 litres of fluid/day
-adequate fibre
-no alcohol
Nutrition therapy for CHF
-carbohydrate requirement is dictated by the
presence of hyperglycemia- possible reasons for hyperglycemia
-if supplements are required then nutrient dense
liquids are the first choice
Nutrition therapy for CHF
-if patient does not want to eat then duodenal
feeding can be initiated
-feedings begin slowly (30 ml/hour) and then
are increased gradually
-fluid and electrolyte status must be carefully
monitored-why?
Nutrition therapy for CHF
-if patient does not want to eat then duodenal
feeding can be initiated
-overly aggressive nutritional support can
worsen CHF resulting in pulmonary edema
-2 kcal/ml and moderate to low sodium
-continuous nasogastric feeding can result in
loss of body weight (fluid) loss and lean body
mass increase without compromising cardiac
status
Nutrition therapy for CHF
if oral and tube feeding fail then parenteral feeding
is instituted
-as with nasogastric- therapy begins slowly
-1500 ml per day to start
-cachetic patient as low as 600 ml/day –why?
-central venous pressure, pulse rate, arterial
blood pressure and urine output are tracked
as fluid input increases
Nutrition therapy for CHF
-at the first sign of nutritional inadequacy, enteral
or parenteral therapy should begin as progression
of nutritional inadequacy is slow and nutritional
goals take longer to obtain
Class activity-what is the best approach to avoiding
CHF?