COPD and other respiratory diseases Flashcards
What is COPD?
“Preventable and treatable disease that is characterised by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles or gases”
COPD includes:
- Emphysema: Damage to alveoli
- Chronic bronchitis: Irritation and swelling of the airways
- Or a combination of both
what is spirometry?
- Common test to assess lung function
- Essential for diagnosis of COPD
Measurements:
* Forced Expiratory Volume in one second (FEV1): This is the maximum amount
of air that can be expelled from the lungs during the first second of breathing out
following a maximal breath in.
* Vital Capacity (VC): This is the maximum amount of air that can be expelled from
the lungs while breathing out following a maximal breath in.
* Forced Vital Capacity (FVC): This is the maximum amount of air that can be
expelled from the lungs while breathing out forcefully. VC and FVC are equal in a
normal lung but can differ in patients who have a chronic lung condition.
* FEV1/FVC: This measures how much air is blown out in the first second
proportional to the total amount blown out of the lung.
risk factors for COPD?
Genes
Exposure to particles: Tobacco smoke, Occupational dusts, organic and inorganic, indoor and outdoor air pollution
Lung growth and development
oxidative stress
gender
age
respiratory infections
previous tuberculosis
socioeconomic status
nutrition
comorbidities
What are the malnutrition rate amongst inpatients with COPD?
30 to 60%
what are the causes of malnutrition in COPD patients?
Poor nutrition and reduced dietary intake
Pulmonary cachexia and systemic inflammation
Frailty and reduced physical function
Sarcopenia and inactivity
What are the consequences of malnutrition?
Being underweight and having a low fat free mass are independently
associated with:
−Increased mortality
−Increased LOS & healthcare costs
−Reduced respiratory function
−Reduced muscle strength
−Reduced exercise capacity
COPD and low BMI
- An observational study of 608 patients admitted with an infective
exacerbation of COPD showed:
−Patients with a low BMI were 2.5 x more likely to die during this
admission
−Patients with >10% unintentional weight loss in the 3-6 months prior to
admission were almost 4 x more likely to be re-admitted within 28
days of discharge
COPD and falls risk, how can a dietitian help?
- 55% increased risk of falls
- COPD was the second most prevalent condition among patients presenting to emergency departments with hip fractures
- Risk factors in the COPD population are similar to those in older adults:
- Includes malnutrition, osteoporosis, muscle weakness
- Inpatients are screened for falls risk on admission.
Obesity and COPD
- Increasingly common
- Associated with decreased measures of lung function
- Increased use of inhaled medications
- Increased dyspnoea
- Increased fatigue
- Decreased heath related quality of life
- Decreased weight bearing exercise capacity
Obesity has been associated with reduced mortality risk in severe COPD
* A meta-analysis of 17 studies evaluated the dose-response relationship between BMI and
mortality:
− Those with a BMI <21.75 kg/m2 had the greatest risk of dying
− BMI 21.75-32kg/m2 had reduced mortality
− Once BMI >32 kg/m2 the protective effect of high BMI was no longer evident
Biochem for COPD
WBC (neutophil and lymphocyte count) – markers of infection
* CRP – marker of inflammation
* Hydration status
* Glucose tolerance
* Renal and hepatic function
* Electrolytes
what are some nutrition support options for COPD?
- food fortification + energy conservation strategies
- Oral Nutrition Supplements
- Nenteral nutrition
what are food fortification + energy conservation strategies for COPD
- Small, frequent meals and snacks
- Make all meals and snacks as nourishing as possible – make every
mouthful count (HPHE) - Rest before meals
- Eat slowly and chew foods well
- Softer and moist foods are often better tolerated
- Eat meals when symptoms are best controlled
- Consider using a home delivered meal service, frozen / tinned foods
- If prescribed oxygen, use this during meals
- Sit upright for meals
how can nutrition support be benifical for COPD
Cochrane Review of 2012 found that nutrition supplementation increases:
* Body weight
* Fat free mass
* Skinfold thickness
* Exercise tolerance
* Midarm muscle circumference
* Respiratory muscle strength
* Health related quality of life
(especially if malnourished)
Do individuals with COPD benefit from consuming high fat, low CHO nutritional supplements?
no
Proposed rationale:
* Less CHO = less CO2 production, which will
decrease the respiratory quotient and
result in improved ventilatory status
* Routine use of high fat, low CHO supplements
is not warranted
* Reduced complications and improved
compliance may be better achieved by
providing small frequent amounts of
nutritional supplement
are antioxidants beneficial for COPD
- Clinical trials and observational studies of individuals with COPD receiving a high antioxidant
intake have not demonstrated a consistent beneficial effect
Vitamin E:
* The ability to reduce biomarkers of oxidative stress has been demonstrated in one RCT but
not another
