Respiratory Diseases

Pathophysiology and Medical Treatments

Respiratory System

• Lungs- airways- alveoli- blood vessels- defense system

• Respiratory pump- Central controller- spinal cord- motor nerves- muscles

Respiratory Diseases

• Lungs- airways-asthma

- alveoli-COPD, pulmonary fibrosis

- blood vessels-pulmonary hypertension

- defense system- inadequate cough, aspiration, immune dysfunction

• Respiratory pump- Central controller-central alveolar hypoventilation

- spinal cord- SCI

- motor nerves- ALS

- muscles- muscular dystrophy

Discussion Topics

• Lung diseases- Asthma

- COPD

- Pulmonary fibrosis

- Lung Transplant

- Pneumonia

• Respiratory Pump Diseases- Muscular Dystrophy

- Spinal Cord Injury

Asthma

• Defined as reversible obstruction or narrowing of the airways- between episodes patients feel normal and have normal

pulmonary function tests

• If you were to see the asthmatic airway under the microscope you would see:- narrowed, edematous airways

- inflammation in the airway walls

- excess mucous secretion and plugging

Asthmatic Airway

Asthma

• Allergy Related (extrinsic)- Immunoglobulin E (IgE)

- Pollens, and animal danders, etc.

- Seasonal

- Younger individuals

• Unrelated to allergy (intrinsic)- Aspirin sensitivity

- Not seasonal

Asthma- Symptoms

• Shortness of breath (dyspnea)

• Wheezing

• Chest tightness

• “Feeling of suffocating”

• Cough

• Exercise induced

Asthma- Physical Findings

• Rapid breathing (tachypnea)

• Perspiring

• Using “accessory” muscles of respiration- sternoclydomastoid, platysma, pectoralis

major and minor

• cyanosis

• tachycardia

• pulsus paradoxus

Asthma- Acute Treatment

• Bronchodilation (opening the airways)- inhaled B-agonists (B2 receptors bronchodilate)

• albuterol, salmeterol, pirbuterol, bronkosol

- parenteral B-agonists

• epinephrine, terbutaline, isoproterenol

- inhaled anticholinergics (cholinergic receptors constrict)

• ipatroprium bromide, glycopyrrolate

- Theophylline

Asthma Treatment-Acute

• Anti-inflammatory- parenteral steroids

• Artificial ventilation- Noninvasive-facemask

- Invasive-endotracheal tube

• High risk

Asthma - ChronicTreatment

• anti-inflammatories are key to prevent exacerbations- inhaled steroids at high dose

• triamcinalone, budesonide, fluticasone, beclomethasone

- mast cell stabilizing drugs• nedocromil, cromolyn

• B-agonists and anticholinergics as needed• Leukotriene inhibitors- zafirleukast (zyflo)- Montelukast (singulair_

• “Stepped care”- Gradual addition of medications

Chronic Obstructive Pulmonary Disease (COPD)• Is a general term for patients with

chronic airflow obstruction that may be due a number of causes- emphysema

- chronic bronchitis

- chronic severe asthma

• > 90% of cases are due to smoking

• Lungs are obstructed and overinflated

Physiologic Derangements in COPD

• Destruction of Alveolar Tissue

• Loss of lung elastic recoil

• Airway obstruction

Chronic Obstructive Pulmonary Disease (COPD)• Functional consequences of airway

disease and chronic lung injury- Obstruction to airflow

- Hyperinflation of the chest

- Improper respiratory muscle function

- Increase work of breathing

COPD- Symptoms

• gradually progressive shortness of breath (over years)- may end up disabled with dyspnea at rest

- may require oxygen

• cough frequently productive of sputum

• leg swelling

• anxiety

COPD- Physical Signs

• Barrel chest

• Tachypnea

• “Pursed-lip” breathing

• Use of accessory muscles

• Diaphragm dysfunction- Hoover sign

- lack of outward movement of abdomen

• Reduced and prolonged expiratory airflow

COPD X-ray

COPD- Treatment

• B-agonists

• Anticholinergics

• Theophylline

• Steroids- only 20 % of patients are steroid

responsive

COPD Treatment

• Pulmonary Rehabilitation

• Lung Transplant

• Lung Volume Reduction Surgery (LVRS)

Pulmonary RehabilitationExercise

Pulmonary RehabilitationBreathing Re-training

Pulmonary RehabilitationTeaching

• Biology of disease

• Medications

• Oxygen

• Travel

• Minimizing energy expenditure

• Interpersonal relationships

Break

COPD-Surgical interventions

• Lung volume reduction surgery (LVRS)

• Lung transplantation

LVRS

• Hypothesis: Hyperinflation of the lungs in COPD is the primary cause of dyspnea. Reducing the sized of the lungs will reduce dyspnea and increase expiratory airflow

• Procedure: Sternotomy with resection of 25 to 30% of each lung

Lung Volume Reduction Surgery

Lung Transplantation

• For very advanced disease

• Age < 65 years

• No other major medical problems

• Post transplant immunosupression- 15-20 medications

Pulmonary Fibrosis

• Scarring of the lung tissue due to inflammation

• Lungs become too small- “restricted”

• Due to a wide range of causes:- drugs

- toxic exposures

- rheumatologic diseases

- idiopathic- “IPF”

Interstitial Lung Disease

Pulmonary Fibrosis- Symptoms

• Dyspnea

• Exercise intolerance

• Cough

• Symptoms associated with systemic disease

Pulmonary Fibrosis- Exam Findings

• Rapid, shallow breathing

• clubbing of the fingers

• “velcro” rales or crackles in the lungs

• cyanosis

• findings associated with systemic disease

Pulmonary Fibrosis- Treatment

• Steroids

• Cytotoxic agents- imuran

- cyclophosphamide

• Lung Transplant

Pneumonia• Common pulmonary disease

• Usually there is an associated host defense problem- aspiration

- foreign body

- immune suppression

• recent viral illness

• More global immune problem

- Ciliary problem

• smoking

• Cystic Fibrosis

Pneumonia Xray

Pneumonia- Symptoms and Physical Findings

• Cough

• Chest pain

• Fever, chills

• Dyspnea

• Evidence of consolidation on lung exam- “bronchial breath sounds”

- egophony

- dullness to percussion

Pneumonia- Treatment

• One or more antibiotics

• Choice will depend on patients age, immune status, seriousness of clinical condition

• Sputum sample with Gram’s stain can be helpful

Spinal Cord Injury

• Level of spinal cord injury is critical

• C2 or above clearly ventilator dependent

• C3-C5- likely ventilator dependent at least partially

• C5 and below usually ventilator independent but cough and secretion clearance is a problem

• Lung volumes appear “restricted”

• Cough and expiratory flow always an issue

Spinal Cord Injury- Respiratory Treatment

• Will depend entirely on level of injury

• Maintaining adequate ventilation is of utmost importance, almost all patients will initially be on a mechanical ventilator

• Clearance of secretions and prevention of pneumonia is also of critical importance- The leading cause of death in the first year following injury is

pneumonia

• Techniques of Secretion Management- Chest physical therapy, assisted cough

- Tracheal suctioning

- In-exsufflator

Spinal Cord Injury- Respiratory Treatment

• Some patients may need only partial ventilation at night

• Non-invasive ventilation may be an option- No tracheostomy

- Less complications

Muscular Dystophy

• Many varieties- Frequently genetic

• Muscle and not nerves are affected

• Progressive loss of function over years

• Primary cause of death is pneumonia

• Currently no medical treatment- Future: ? Gene therapy

Muscular Dystrophy

• Often associated with scoliosis

• Patients will be short of breath

• Patients will often breath less well at night and have associated sleep apnea

• Treatment will be aimed at relieving symptoms and prolonging life

• Noninvasive ventilation is a definite option

Mouthpiece Ventilation-”SIP”

Nocturnal Ventilation

Cough-Assist Device

Noninvasive Ventilation