Respiratory System pathology detailed topic

Pathology of respiratory system

1. PATHOLOGY and MICROBIOLOGY II P2M-85

2. Objectives: Reduction of pulmonary functions Signs and symptoms of pulmonary diseases Respiratory failure Obstructive pulmonary diseases

3. Reduction of Pulmonary Function Inadequate blood flow to the lungs – hypoperfusion Inadequate air flow to the alveoli – hypoventilation Alveoli ( The alveoli are  where the lungs and the blood exchange oxygen and carbon dioxide  during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.) 4

4. Hospital-acquired pneumonia (HAP), or nosocomial pneumonia (NP) Pneumonia that develops 48 h or more after admission to a hospital and does not include pneumonia that a patient had contracted when admitted or before being admitted. Often,  nosocomial infections  are caused by multidrug-resistant pathogens acquired via invasive procedures, excessive or improper antibiotic use, and not following infection control and prevention procedures. the most common is the bacterium  Staphylococcus aureus . Other common pathogens like  Escherichia coli ,  Enterococci , and  Candida  normally found on the skin and mucous membranes. 5

5. Types of Nosocomial Infections Bacterial infections. Bacteria are the most common cause of nosocomial infections. Common bacteria include  E. coli  and  staph . Fungal infections.  The most common fungi that cause nosocomial infections are  Candida  (thrush) and  Aspergillus .‌ Viral infections.  Common nosocomial infections caused by viruses are influenza (flu) and  respiratory synctial virus .

6. Symptoms Fever Burning sensation while urinating Cough Extreme tiredness or weakness Skin redness and soreness around a surgical or needle wound Sweating Muscle soreness Nausea and vomiting  

7. Treatment Antibiotics.  Rest.  Fluids. 

8. Prevention Fully disinfecting skin and equipment Washing hands regularly Wearing protective equipment like face masks and gloves Regularly changing urinary catheters, and removing them as soon as possible Removing hair near a surgical area Prescribing antibiotics only when needed

9. Signs and Symptoms of Respiratory Disease Dyspnea – subjective sensation of uncomfortable breathing, feeling “short of breath” Ranges from mild discomfort after exertion to extreme difficulty breathing at rest. Tachypnea (rapid breathing) Hypopnea (shallow breathing) Hyperpnea (deep breathing), Apnea (absence of breathing). Breathing problems may occur in conditions affecting the lungs alone or may be seen in association with more generalized conditions, such as  dehydration  or infection 10

10. Dyspnea cont. Due to: Airway obstruction Greater force needed to provide adequate ventilation Wheezing sound due to air being forced through airways narrowed due to constriction or fluid accumulation 11

11. Signs of Dyspnea: Flaring nostrils( Nasal flaring occurs  when the nostrils widen while breathing . It is often a sign of trouble breathing) Use of accessory muscles in breathing Retraction (pulling back) of intercostal spaces 12

12. CAUSES Asthma Anxiety pneumonia choking on or inhaling something that blocks breathing passageways allergic reactions Anemia ( Anemia is a  condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body's tissues) serious loss of blood, resulting in anemia exposure to dangerous levels of carbon monoxide heart failure hypotension which is low  blood pressure pulmonary embolism, which is a blood clot in an artery to the lung collapsed lung

13. COUGH Attempt to clear the lower respiratory passages by abrupt and forceful expulsion of air Most common when fluid accumulates in lower airways 14

14. Cough may result from: Inflammation of lung tissue Increased fluid secretion in response to mucosal irritation Inhalation of irritants(Dust etc.) Mucosal interruption – such as tumor invasion of bronchial wall Excessive blood pressure in pulmonary capillaries Pulmonary edema – excess fluid passes into airways 15

15. When cough can raise fluid into pharynx, the cough is described as a productive cough , and the fluid is sputum . Production of bloody sputum is called hemoptysis Usually involves only a small amount of blood loss Not threatening, but can indicate a serious pulmonary disease Tuberculosis, lung abscess, cancer, pulmonary infarction. 16

16. If sputum is pus-filled, and infection of lung or airway is indicated. Cough that does not produce sputum is called a dry, nonproductive or hacking cough. Acute cough is one that resolves in 2-3 weeks from onset of illness or treatment of underlying condition. Caused by infections, allergIES , acute bronchitis, pneumonia, congestive heart failure, pulmonary embolus, or aspiration. 17

17. Chronic Cough A chronic cough is one that persists for more than 3 weeks. In nonsmokers, almost always due to asthma, or gastroesophageal reflux disease Chronic Cough is common. In smokers, chronic bronchitis is the most common cause, although lung cancer should be considered . 18

18. Cyanosis When blood contains a large amount of unoxygenated hemoglobin , it has a dark red-blue color which gives skin a characteristic bluish appearance. Most cases arise as a result of reduced blood flow, which allows hemoglobin to give up more of its oxygen to tissues- peripheral cyanosis. Best seen in nail beds Due to cold environment, anxiety, etc. 19

19. Central cyanosis can be due to : Abnormalities of the respiratory membrane Mismatch between air flow and blood flow Expressed as a ratio of change in ventilation (V) to perfusion (Q) : V/Q ratio : V – ventilation – the air that reaches the alveoli. Q – perfusion – the blood that reaches the alveoli via the capillaries. In persons with dark skin can be seen in the whites of the eyes and mucous membranes . 20

20. In adults not evident until severe hypoxemia is present Clinically observable when reduced hemoglobin levels reach 5 g/ dl. Severe anemia and carbon monoxide give inadequate oxygenation of tissues. Individuals with polycythemia may have cyanosis when oxygenation is sufficient. Polycythemia refers to  an increase in the number of red blood cells in the body 21

21. Pain in Respiratory System Originates in pleurae, airways or chest wall Inflammation of the parietal pleura causes sharp or stabbing pain when pleura stretches during inspiration Usually localized to an area of the chest wall , where a pleural friction rub can be heard Laughing or coughing makes pain worse Common with pulmonary infarction due to embolism ( An embolism is  a blocked artery caused by a foreign body) 22

22. Inflammation of trachea or bronchi produce a central chest pain that is pronounced after coughing Must be differentiated from cardiac pain High blood pressure in the pulmonary circulation can cause pain during exercise that often mistaken for cardiac pain (angina pectoris) 23

23. Clubbing The selective enlargement of the end of a digit (finger or toe). Usually painless Commonly associated with diseases that cause decreased oxygenation Lung cancer Cystic fibrosis Lung abscess Congenital heart disease 24

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25. Respiratory Failure The inability of the lungs to sufficiently move oxygen into the bloodstream and to clear it of carbon dioxide. Can be acute: Direct injury to the lungs, airways or chest wall Indirect due to injury of another body system, such as the brain or spinal cord. 26

26. Chronic respiratory failure Due to progressive hypoventilation from airway obstruction Respiratory failure always presents a serious threat Dyspnea always present, but may be difficult to detect a change in a chronic patient Memory loss visual impairment drowsiness Headache due to increased intracranial pressure due to cerebral vasodilation 27

27. Two principal patterns: Hypoxic Respiratory Failure : when pO 2 falls to or below 60 mm Hg Typically seen in chronic bronchitis and emphysema, in lung due to bacterial infection, or in lung collapse, pulmonary hypertension, pulmonary embolism and ARDS. Initially, produces headache and nervous anxiety, soon followed by a decline in mental activity, and confusio n. 28

28. With a progressive lowering of pO 2 , more widespread tissue damage and loss of consciousness occurs. Renal hypoxia (i.e.,  decreased oxygen tension in the kidney ) Renal hypoxia can cause loss of homeostatic balance and accumulation of wastes to complicate the problem 29

29. Hypoxic-Hypercapnic Respiratory Failure When arterial pCO2 (normally 40 mm Hg) exceeds 45 mm HG, condition is called hypercapnia Most often, obstructive conditions produce this form of respiratory failure, as can hypoventilation from CNS problem, thoracic cage or neuromuscular abnormalities 30

30. Attempts to compensate include increased heart rate and vasodilation, which produces warm, moist skin. CNS effects produce muscular tremors, drowsiness and coma. Hypercapnia also produces acidosis. 31

31. Obstructive Pulmonary Disease Characterized by airway obstruction that is worse with expiration. More force is required to expire a given volume of air, or emptying of lungs is slowed, or both. The most common obstructive diseases are asthma, chronic bronchitis, and emphysema. Many people have both chronic bronchitis and emphysema, and together these are often called chronic obstructive pulmonary disease - COPD 32

32. Major symptom of obstructive pulmonary disease is dyspnea, and the unifying sign is wheezing. Individuals have increased work of breathing, a decreased forced expiratory volume. 33

33. References 1- Bousquet J et al. Management of chronic respiratory and allergic diseases in developing countries. Focus on sub-Saharan Africa. Allergy, 2003, 58:265–283. 2- Enarson DA, Ait -Khaled N. Cultural barriers to asthma management. Pediatric Pulmonology, 1999, 28:297–300 3- Masoli M et al. The global burden of asthma: executive summary of the GINA Dissemination Committee Report. Allergy, 2004, 59:469–478.

34. Outcomes: Students will be able to learn: Reduction of pulmonary functions Signs and symptoms of pulmonary diseases Respiratory failure Obstructive pulmonary diseases