Download Gas Exchange

Drugs Affecting the
Lower Respiratory
System
Gas Exchange/Oxygenation:
Lower Respiratory System
Oxygen Transport:
http://www.youtube.com/watch?v=WXOBJEXxNEo
Lower Respiratory Tract
Physiology
 The lower respiratory tract is almost sterile because of various
defense mechanisms in the upper respiratory system.
 Protective mechanisms
 All the tubes in the lower airway contain goblet cells, which
secrete mucus to entrap any particles.
 Microorganisms and other foreign bodies are removed from
the air by tiny hair-like structures called cilia.
 Gas exchange, perfusion, and respiration
 Lung tissue receives its blood supply from the bronchial
artery, which branches directly off the thoracic aorta.
 Ventilation
 The act of breathing is controlled by the central nervous
system (CNS).
Lower Respiratory Disorders
COPD – chronic obstructive
pulmonary disorder
Airway obstruction with
increased resistance of airflow to
lung tissues
 Four major lung disorders:
 Chronic bronchitis
Bronchiectasis – irreversible
damage to bronchioles
 Emphysema – irreversible
damage to alveoli
 Asthma – reversible, common
in childhood
Restrictive pulmonary disease
Decrease in total lung capacity
from fluid accumulation or loss
of elasticity of the lung
 Examples:
 Pulmonary edema
 Pulmonary Fibrosis, genetic
e.g. Cystic Fibrosis
 Lung tumors
 Thoracic deformities
(scoliosis)
 Thoracic muscular disorders
e.g. Myasthenia Gravis
Pathophysiology
 Acute bronchitis is caused most frequently by
viruses.
 Chronic bronchitis is long-standing, largely
irreversible inflammation of the bronchial tree.
 Asthma is a disorder characterized by recurrent
episodes of bronchospasm, bronchial muscle
spasm that leads to narrowed or obstructed airways.
Pathophysiology (cont’d)
 Emphysema is an abnormal distention of the lungs with air
characterized by loss or degeneration of elastic tissue,
disappearance of capillary walls, and breakdown of the
alveolar walls.
 Pneumonia is an inflammation of the lungs. It can be
caused by bacterial or viral invasion of the tissue or by
aspiration of foreign substances into the lower respiratory
tract.
 Cystic fibrosis is a hereditary disease that affects the
functioning of the body’s exocrine glands: the mucussecreting and sweat glands.
Pathophysiology of Asthma
 Primary response is chronic inflammation from
exposure to allergens or irritants.
 This leads to airway hyper-responsiveness and
acute airflow limitations
 Inflammatory mediators cause early-phase
response.
Pathophysiology of Allergic Asthma
 Asthma is triggered
when an irritant crosslinks antigen receptors
on mast cells.
 Histamine and other
inflammatory responses
are triggered
Factors Causing Obstruction in
Asthma
Bronchioles become
occluded by muscle
spasms, swollen mucosa,
and mucus in the lumen.
Clinical Manifestations of Asthma
Unpredictable and variable
 Recurrent episodes
of wheezing,
breathlessness,
cough, and tight
chest
 May be abrupt or
gradual
 Lasts minutes to
hours
Expiration may be
prolonged.
 Inspiration-expiration
ratio of 1:2-4
 Bronchospasm,
edema, and mucus in
bronchioles narrow
the airways.
 Air takes longer to
move out.
Clinical Manifestations
Signs of hypoxemia
 ↑ pulse and blood pressure
 Restlessness
 ↑ anxiety
 Inappropriate behavior
 Pulsus paradoxus (drop in systolic BP during
inspiratory cycle >10 mm Hg)
Complications
Life-threatening asthma
 pO2 levels drop
 Too short of breath (dyspneic) to speak
 Perspiring profusely
 Drowsy/confused
 Require hospital care and often admitted
to ICU
Mucolytic Drugs
 Mucolytics break down mucus.
 The drugs can be administered by a nebulizer or by
direct instillation into the trachea.
 Mucolytics usually are reserved for patients who have
major difficulty mobilizing and coughing up
secretions.
Prototype drug:
acetylcysteine (Mucomyst)
Acetylcysteine: Core Drug
Knowledge
 Pharmacotherapeutics
 Used to liquefy the thick, tenacious secretions.
 Pharmacodynamics
 It splits disulfide bonds that are responsible for holding the
mucous material together.
 Contraindications and precautions
 Hypersensitive
 Adverse effects
 Bronchospasm, bronchoconstriction, chest tightness, a
burning feeling in the upper airway, and rhinorrhea
 Unpleasant (sulfur, rotten egg) smell with
Acetylcysteine: Planning and
Interventions
 Maximizing therapeutic effects
 Administer an inhaled beta-agonist before administering
acetylcysteine.
 Minimizing adverse effects
 Inform the patient that nebulization may produce an
initially disagreeable odor, but that this odor is transient.
Bronchodilators
 Bronchodilators are drugs used to
dilate the airways.
 Inhalation is the most frequent method using metered-
dose inhalers (MDIs) or dry-powder inhalers (DPIs).
 Beta-agonists (sympathomimetics)
 One of the actions of beta stimulation in the sympathetic
nervous system is dilation of the bronchi and increased
rate and depth of respiration.
Prototype drug: albuterol (Proventil,
Ventolin)
Metered Dose Inhalers
Nebulizers
Albuterol: Core Drug Knowledge
 Pharmacotherapeutics
 Bronchodilator in managing Chronic Airway Limitation
disease and asthma
 Pharmacodynamics
 It selectively stimulates receptors of the smooth muscle in
the lungs, the uterus, and the vasculature that supplies the
skeletal muscle.
 Side effects
 Tachycardia, palpitations, anxiety, tremors, headache,
insomnia, muscle cramps, and upset stomach.
Albuterol: Nursing Diagnoses and
Outcomes
 Anxiety related to sympathomimetic effects of
albuterol administration
 Ineffective Tissue Perfusion: Cardiopulmonary
related to rebound bronchoconstriction caused
by overuse of albuterol
Albuterol: Teaching, Assessment,
and Evaluation
 Patient and family education
 Teach patients that inhaled albuterol is a
“rescue drug.”
 Teach patients how to use an MDI.
 Explain the importance of limiting caffeine
intake.
Anticholinergic Agents
 Inhaled anticholinergic drugs are considered first-line
treatment for patients with Chronic Airway Limitation
(CAL).
 Anticholinergic agents diminish the effect of
acetylcholine.
 In the respiratory system, use of inhaled anticholinergic
drugs stops bronchoconstriction.
Prototype drug:
ipratropium bromide
(Atrovent)
Ipratropium Bromide: Core Drug
Knowledge
 Pharmacotherapeutics
 Used for maintenance treatment of bronchospasm
 Pharmacodynamics
 Antagonizes the action of acetylcholine by blocking
muscarinic cholinergic receptors
 Side effects
 Cough, hoarseness, throat irritation
 Adverse effects
 Paradoxic acute bronchospasm
Ipratropium Bromide:
Nursing Concerns
 Risk for Injury (anaphylactic reactions) related to
allergies to soybeans, legumes, or soya lecithin.
Ipratropium Bromide: Teaching,
Assessment, and Evaluation
 Patient and family education
 Advise patients that ipratropium is used
prophylactically (prevention).
 Remind patients that overuse of ipratropium
may induce adverse effects.
Xanthine Derivatives
 The xanthine derivatives, including theophylline,
aminophylline, and caffeine, come from a variety
of naturally occurring sources.
 They are excellent bronchodilators but do not
work as rapidly as beta-adrenergic agonist drugs.
Prototype drug:
*theophylline (Theodur)
*Not on drug list
Theophylline: Core Drug Knowledge
 Pharmacotherapeutics
 Indicated for the symptomatic relief or prevention of
bronchial asthma and reversal of bronchospasm
 Administered orally and on a routine basis for maintenance
 Pharmacodynamics
 It is believed that bronchodilation is caused by inhibition
of phosphodiesterase.
 Adverse effects
 Adverse effects related to theophylline use are related
directly to serum levels of the drug.
Theophylline: Nursing Concerns
 Disturbed Sensory Perception: CNS effects of
irritability, insomnia, and dizziness.
 Ineffective Tissue Perfusion: Cardiopulmonary
related to cardiac effects of the drug.
 Risk for Injury related to headache, GI effects, and
CNS effects.
Anti-Inflammatory
 In addition to bronchodilators, anti-
inflammatory agents are used to manage
respiratory disorders, especially asthma.
 Inhaled glucocorticoid steroids
 Glucocorticoid steroids are the most effective anti-
inflammatory drugs available for managing respiratory
disorders.
 Inhaled corticosteroid (ICS) agents have become
first-line treatment for persistent asthma.
Prototype drug: fluticasone/salmeterol
(Advair), beclomethasone (Q-var)
fluticasone/salmeterol:
Core Drug Knowledge
 Pharmacotherapeutics
 Used to prevent bronchospasm
 Used for maintenance (routine – not PRN)
 Pharmacodynamics
 Inhibit the production of leukotrienes and prostaglandins
through interference with arachidonic acid metabolism.
 Side/Adverse effects
 Sore throat, hoarseness, coughing, dry mouth, and
pharyngeal and laryngeal fungal infections
fluticasone/salmeterol:
Nursing Concerns
 Impaired Verbal Communication related to
dysphonia and cough
 Risk for oral infection related to
immunosuppression
fluticasone/salmeterol:
Core Drug Knowledge
 Patient and family education
 Patient education is important for inhaled
steroid therapy.
 Importance of daily use, regardless of the
absence of symptoms
 Rinse mouth after use of
fluticasone/salmeterol (Advair)
Leukotriene Receptor Antagonist
 Leukotrienes are inflammatory mediators that are
powerful bronchoconstrictors and vasodilators.
 Leukotrienes have been identified as important
mediators in the pathology and symptomatology of
asthma.
 They are used for prevention of asthma attacks.
Prototype drugs:
*montelukast (Singulair)
*Not on drug list
Montelukast : Core Drug Knowledge
 Pharmacotherapeutics
 Prophylaxis or treatment of chronic asthma
 Pharmacodynamics
 Blocks receptors for the leukotrienes bound to
the amino acid cysteine
 Side/Adverse effects
 Headache, gastritis, pharyngitis, and rhinitis
 Numerous drug interactions
Montelukast : Teaching,
Assessment, and Evaluation
 Patient and family education
 Explain that montelukast is used in
maintenance therapy.
 Encourage patients to take nonnarcotic
analgesics if headache occurs.
Challenge Question
Acetylcysteine (Mucomyst) for respiratory use is
administered by:
A. Inhalation
B. SC
C. Oral
D. IV
A. Inhalation.
Oral use is indicated for acetominophen overdose.
Challenge Question
Albuterol is given for acute exacerbation of Chronic
Airway Limitation (CAL) or asthma.
A. True
B. False
A. True
Challenge Question
Patients using inhaled steroids are at a high risk for
developing
A. Oral bacterial infection
B. Oral viral infection
C. Oral fungal infection
C. Oral fungal infection
Question
Montelukast is used for
A. Prophylaxis – prevention of attacks
B. Acute attack
C. Infection
D. All of the above
A. Prophylaxis – prevention of attacks
Match Drug + Administration
 Ipratroprium
(Atrovent)
 Fluticasone/
salmeterol (Advair)
 Albuterol
(Proventil)
 Routine
 PRN
 Routine
Homework Activity - 1:
Orientation to Shadow Health Digital
Clinical Experience (DCE)
You will need to be in a private place or use head phones for this activity due
to the audio/video component.
CLASS PIN: February2016-4444-1603-7874-2405
 1. Log in and create an account. There is no cost to you for this
activity.
 2. Use Class PIN above to find our class account.
 3. Complete the Shadow Health DCE Orientation (Due by March
11th)
Homework Activity – 2
Quiz #6: The Respiratory
System