Pathophysiology - Lecture 15 - Respiratory Disorders II

What is Cystic Fibrosis?

Inherited (genetic) disorder - Gene located on chromosome 7, Disorder of chloride transport proteins which leads to → Tenacious mucus from exocrine gland

Primary effects of Cystic Fibrosis seen in lungs and pancreas

• Mucus obstructs airflow in bronchioles and small bronchi.

• Permanent damage to bronchial walls

• Infections are common. - Commonly caused by Pseudomonas aeruginosa and Staphylococcus aureus

What happen to Digestive tract during Cystic Fibrosis?

• Meconium ileus in newborns (bowel blockage)

• Blockage of pancreatic ducts

• Obstruction of bile ducts

• Malabsorption problems

What happen to Reproductive tract during Cystic Fibrosis?

• Obstruction of vas deferens (male)

• Obstruction of cervix (female)

What happen to Sweat glands during Cystic Fibrosis?

Sweat has high sodium chloride content

s/s of Cystic Fibrosis

• Meconium ileus may occur at birth

• Salty skin - May lead to performing sweat test and diagnosis of cystic fibrosis

• Signs of malabsorption - Steatorrhea, abdominal distention

• Chronic cough and frequent respiratory infections - Tend to increase over time

• Failure to meet normal growth milestones

Dx of Cystic Fibrosis

• Genetic testing

• Sweat & Stool testing

• Radiography, pulmonary function tests

• Blood gas analysis

Tx for Cystic Fibrosis

• Replacement therapy (enzymes for digestion)

• Well-balanced diet

• Chest physiotherapy

• Gene therapy - corrects chloride protein, showing results in some patients

What are 3 types of Lung Cancer?

• Bronchogenic carcinoma - Arises from bronchial epithelium

• Squamous cell carcinoma - Usually develops from epithelial lining of a bronchus

• Adenocarcinomas and bronchoalveolar cell carcinomas - Usually found on periphery of lung

What is Small Cell Carcinoma?

• Makes up 15% of all lung cancers

• Characterized by presence of small round - oval cells that grow in clusters

• Rarely seen in people who have never smoked

What is prognosis of Small Cell Carcinoma?

Very poor prognosis

• ~70% metastasis at time of diagnosis / 50% die in 12-15 weeks (without treatment)

• Brain metastasis common

What is Squamous Cell Carcinoma?

• Moderate to poor differentiation

• makes up 30% of all lung cancers, 2nd most common

• Close correlation to smoking

• more common in males

Dx of Squamous Cell Carcinoma

• Cells can be detected in sputum - Early detection

• most occur centrally in large bronchi

• Uncommon metastasis that is slow - effects the liver, adrenal glands and lymph nodes

• Not easily visualized on x-ray (may delay dx)

• Most likely presents as a Pancoasts tumors

What is Adenocarcinoma?

• Increasing in frequency. Most common type of Lung cancer (40% of all lung cancers)

• Most common type for nonsmokers

• Origin in bronchiolar or alveolar tissue

• Sometimes found in areas of scarring

What is prognosis of Adenocarcinoma?

Poorer prognosis than squamous

Dx of Adenocarcinoma

• Clearly defined peripheral Lesions

• Glandular appearance under a microscope

• Easily seen on a chest x-ray

• Highly metastatic in nature - develop in brain, liver, adrenal or bone metastasis

What is Large Cell Carcinomas?

• Makes up 15% of all lung cancers

• Poorly differentiated cells

• Tends to occur in the outer part (periphery) of lung, invading sub-segmental bronchi or larger airways

• Metastasis is slow BUT

• Early metastasis can occur to the kidney, liver, & adrenal glands

s/s of Lung Cancer

• Sometimes lung cancer does not cause any symptoms and is only in a routine x-ray

• Will depend upon the location, size of the tumor, degree of obstruction and existence of metastases

Tumor effects of Lung Cancer

• Obstruction of airflow into a bronchus

• Inflammation and bleeding surrounding the tumor

  • Cough, hemoptysis, and secondary infections

Early signs of Lung Cancer

• Persistent productive cough

• Detection on radiograph

• Hemoptysis

• Pleural involvement, Chest pain

• Hoarseness, dysphagia, facial or arm edema, headache

• Atelectasis

Systemic signs of Lung Cancer

Weight loss, anemia, fatigue

What is paraneoplastic syndrome?

Indicated by signs of an endocrine disorder - Related to the specific hormone secreted

What are signs of metastases for Lung Cancer?

• Bone pain, Cognitive deficits, Motor deficits

Dx of Lung Cancer

• Specialized helical CT scans and MRI

• Chest radiography

• Bronchoscopy

• Biopsy and mediastinoscopy

Tx for Lung Cancer

• Surgical resection or lobectomy

• Chemotherapy and radiation

• Photodynamic therapy

What is Aspiration?

• Passage of food, fluid, emesis, other foreign material into trachea and lungs

• Common problem in young children or individuals laying down when eating or drinking

What results from Aspiration?

• Obstruction - Aspirate is a solid object

• Inflammation and swelling - Aspirate is an irritating liquid

• Predisposition to pneumonia

What are potential complications of Aspiration?

• Aspiration pneumonia - Inflammation — gas diffusion is impaired

• Respiratory distress syndrome - May develop if inflammation is widespread

• Systemic effects - When aspirated materials (solvents) are absorbed into blood

s/s of Aspiration

• Coughing and choking with dyspnea

• Loss of voice if total obstruction

• Stridor and hoarseness - Characteristic of upper airway obstruction

• Wheezing - Aspiration of liquids

• Tachycardia and tachypnea

• Nasal flaring, chest retractions, hypoxia - with severe respiratory distress

• Cardiac or respiratory arrest

What is Obstructive Sleep Apnea?

Result of pharyngeal tissue collapse during sleep

• Leads to repeated and momentary cessation of breathing

• Men are affected more often than women

• Obesity and aging are common predisposing factors

Tx for Obstructive Sleep Apnea

• Continuous positive airway pressure pump (CPAP machine)

• Oral appliances that reduce collapse of pharyngeal tissue

• Surgery - Uvulectomy

What is Asthma?

Bronchial obstruction - Occurs in persons with hypersensitive or hyperresponsive airways

What is Extrinsic Asthma?

Acute episodes triggered by type I Hypersensitivity reactions - pollen, dust, etc

What is Intrinsic Asthma?

• Onset during adulthood

• Hyperresponsive tissue in airway initiates attack

What are stimuli of Intrinsic Asthma?

• Respiratory infections

• Stress

• Exposure to cold

• Inhalation of irritants

• Exercise

• Drugs

Pathophysiological changes of bronchi and bronchioles during Asthma:

• Inflammation of the mucosa with edema

• Bronchoconstriction - Caused by contraction of smooth muscle

• Increased secretion of thick mucus in airways

s/s of Asthma

• Cough, marked dyspnea, tight feeling in chest

• Wheezing

• Rapid and labored breathing

• Expulsion of thick or sticky mucus

• Tachycardia - Might include pulsus paradoxus - (Pressure difference reverses on inspiration and expiration)

• Hypoxia

Respiratory alkalosis

-Initially caused by hyperventilation

Respiratory acidosis

-Caused by air trapping

Severe respiratory distress

-Hypoventilation leads to hypoxemia and respiratory acidosis

Respiratory failure

-Indicated by decreasing responsiveness, cyanosis

Status asthmaticus

• Persistent severe attack of asthma

• Does not respond to usual therapy

• Medical emergency!

• May be fatal because of severe hypoxia and acidosis

General measures for Asthma

Measures for acute attacks of Asthma