Obstructive pulmonary disease

• Pulmonary obstructives diseases:

  Asthma, COPD, cystic fibrosis
• Pulmonary obstructive diseases are characterized by the narrowing or obstruction of the airways. It is caused by secretions, inflammation of the airways, bronchospasm of smooth muscle or destruction of lung tissue
• People with COPD display characteristics of both chronic bronchitis and emphysema

  Emphysema: destruction of alveoli

  Chronic bronchitis: chronic productive cough for 3 months in 2 successive years
• Causes of COPD are cigarette smoking, occupational chemical and dusts, heredity, frequent childhood lung infections
• Statistics of COPD:

  cigarette smoking is responsible for 80-90% of COPD pts

  10% of canadians over 35 have COPD

  20% of smokers develop COPD
• Tobacco smoke contains over 4000 chemicals, 60 of them are known causes of cancer
• Effects of cigarette smoking:

  • increase of goblet cells = increase mucus production
  • injures smaller airways
  • damage ciliary activity (push up the mucus)
  • damage of alveolar walls
  • carbon monoxide binds to hemoglobin which decreases its capacity to carry oxygen
• Lung changes in COPD

  • bronchioles lose shape and are clogged with mucus
  • walls of alveoli are destroyed so there are fewer larger alveoli meaning less possible gas exchange
• Noxious particles lead to inflammation of the airways, remodeling of the patient‘s lung and parenchymal (tissue destruction) which then leads to COPD
• Important COPD pathophysiologies:

  • hyperinflation of lungs (barrel chest)
  • loss of elastic recoil
  • gas exchange abnormalities
  • cilia dysfunction
• Chronic bronchitis affects the bronchioles (inflammation and excess mucus) VS emphysema affects the alveoli (alveolar membranes break down)
• COPD is a ventilation and diffusion problem
• Clinical manifestations of COPD are coughing, sputum production and dyspnea. Dyspnea happens with exertion at first, then at rest and then starts interfering with daily activities
• Dyspnea scale has 5 grades

  Grade 1: after strenuous exercice

  Grade 2: when hurrying on the level or walking up a hill

  Grade 3: walks slower than people and stops for breaths when walking at a normal pace

  Grade 4: stops to breathe after walking 100 yards

  Grade 5: too breathless to leave the house
• Stages of COPD are mild (grade 2), moderate (grade 3-4), severe (grade 5) and very severe
• Diagnostic study for COPD is FEV1, the forced expiratory volume in 1 second (amount of air exhaled). Above 80% is normal
• Progression of manifestations include the use of accessory and intercostal muscle, cachexia (severely underweight), anorexia (loss of appetite) and chronic fatigue
• Possible physical examination findings for COPD are prolonger expiratory phase, wheezes, decreased breath sounds, anterior and posterior diameter, cyanosis
• As COPD progresses, abnormal gas exchange occurs. This results in hypoxemia (decreased oxygen in blood) and hypercapnia (increased CO2 in blood).
• The respiratory center in the brain controls our drive to breathe with the accumulation of CO2. As COPD progresses, the respiratory center loses its sensitivity to elevated CO2 levels and our drive to breathe comes from hypoxemia
• If we administer too much oxygen to patients with advanced COPD, we suppress their drive to breathe (which is normally hypoxemia). This may result in hypercapnia (too much CO2 in blood)
• Complications of COPD include acute exacerbation of COPD, pneumonia, depression and anixety
• Acute exacerbation of COPD is a sustained worsening of COPD symptoms with changes in usual dyspnea, cough and sputum. It is often caused by infections (URTI), air pollution, allergens, irritants or cold air.
• COPD management includes pulmonary rehabilitation programs (exercice program and breathing exercises), long term oxygen therapy at home and drug therapy
• Pursed lip breathing is effective for COPD patients as it imposes a slight obstruction to expiration air flow at the mouth. It helps prop open the airways and assists lung emptying which helps with dyspnea and prevents alveoli collapse
• Nursing management for COPD include exercice, nutrition (high calorie and protein diet), energy conserving strategies, sexual activity and end of life issues
• Smoking cessation strategies

  • motivational interviewing
  • nicotine replacement therapy (patch, gum, nasal spray, inhaler)
  • non nicotine products that release dopamine
  • cessation programs
  • peer support systems and counseling
• The best position to improve gas exchange is the tripod position, sitting in a chair slightly leaning forward
• An appropriate exercice goal to help increase activity tolerance is a 20 minute walk