Gilead -Topics in Human Pathophysiology

Fall 2009 Drug Safety and Public Health

Respiratory system and Disease

• Respiratory System structures– Airways– Respiratory interface– Gas transport– Lungs and ventilation

• Selected Respiratory Disorders

Unlabeled Figure 10.1

Figure 10.1

Respiratory Interface

• Alveolar wall• Capillary wall• Surfactant• Gas Exchange occurs by diffusion

Figure 10.8

Gas Transport

• Oxygen

• Carbon dioxide

Figure 10.7

Respiratory Disorders

• H1N1• Asthma• Cystic fibrosis• Pulmonary aspergillosis• Pneumonia

H1N1• Cause

– Influenza A virus• Symptoms

– Fever– Sore throat– Cough– Body aches– Headache– Chills– Fatigue– Vomiting and diarrhea

H1N1

H1N1

• Susceptible populations• Antivirals for influenza – Tamiflu (oseltamivir),

Relenza (zanamivir), peramivir• Complications

– Pneumonia and respiratory failure– Bronchitis– Ear infections– Sinus infections

Asthma

Cystic fibrosis

• Inherited disorder causing a defect in a cell membrane Cl- channel

• Causes thick sticky mucus buildup in airways and ducts of pancreas, etc.

• Shortens lifespan because of pneumonia, malnutrition, etc.

Pulmonary aspergillosis

• Fungal lung infection• Common with AIDs patients and cystic fibrosis

patients• Treated with Ambisome (amphoterocin B),

one of several antifungals, alters fungal cell permeability

Pulmonary Aspergillosisfrom an AIDS patient during autopsy

http://www.ispub.com/ostia/index.php?xmlFilePath=journals/ijid/vol6n1/aspergillosis.xml

Pneumonia

• Fluid buildup in lung alveoli• Thickens respiratory interface, interrupting

diffusion of gases• Caused by a wide variety of microorganisms

including aspergillus and pneumocystis fungi, influenza virus (Tamiflu), cytomegalovirus (Vistide)

Pneumonia

Tests for Lung Function

• Chest X-ray (CXR)• Pulmonary function tests• Sputum cultures• Pulse oximetry• Arterial Blood Gases (ABGs)

Pneumonia X-ray

http://www.med-ed.virginia.edu/courses/rad/cxr/pathology3chest.html

Figure 22.16a

Pulmonary Function Tests

Figure 22.16a

FEV1

Should be at least 80% of

VC

FEV1

Should be at least 80% of

VC

(VC)

Sputum Culture

•Patient donates a sputum sample•It is cultured with various media to determine causative agent of lung infection

Pulse Oximetry

•Measures arterial hemoglobin oxygen saturation•Normal is > 95%•Indicator of effectiveness of respiratory interface and gas diffusion

Arterial Blood Gases

• pH• PCO2

• PO2

• O2 Saturation

• HCO3-