بسم الله الرحمن الرحيم

1. بسم الله الرحمن الرحيم

2. Apneumothorax by Prof. Entesar Sayed AhmedProfessor Of Chest Diseases Faculty Of Medicine For GirlsAl-Azhar Universty2007

3. Apneumothorax • Apneumothorax, orcollapsed lung, is a potentialmedical emergencycaused by accumulation of air or gas in thepleural cavity, occurring as a result of disease or injury .

4. Pleural Pressure • Pleural pressure, or Ppl, is the pressure surrounding the lung, within the pleural space. • During quiet breathing, the pleural pressure is negative; that is, it is below atmospheric pressure .

5. The size of the lung is determined by the difference between the alveolar pressure and the pleural pressure, or the transpulmonary pressure. • The bigger the difference, the bigger the lung.

6. As a result of gravity, in an upright individual the pleural pressure at the base of the lung base is greater (less negative) than at its apex; • when the individual lies on his back, the pleural pressure becomes greatest along his back..

7. Since alveolar pressure is uniform throughout the lung, the top of the lung generally experiences a greater transpulmonary pressure and is therefore more expanded and less compliant than the bottom of the lung .

8. TYPES OF PNEUMOTHORAX • Primary spontaneous pneumothoraces • Secondary spontaneous pneumothoraces • Traumatic pneumothoraces • Iatrogenic pneumothorax • A tension pneumothorax

9. Primary spontaneous pneumothoraces • Primary spontaneous pneumothoraces result from apical pleural blebs lying under the visceral pleura. • Primary spontaneous pneumothoraces are typically observed in tall young people without parenchymal lung disease because of increased shear forces in the apex.

10. While patients do not have overt parenchymal disease, they commonly are smokers. • Several genetic disorders have been linked to primary spontaneous pneumothorax. • Marfan syndrome, homocystinuria, and Birt-Hogg-Dube syndrome are among such disorders.

11. The spontaneous pneumothorax occurs in about 22% of patients with this syndrome. • The gene responsible for this syndrome has been identified and is located on chromosome 17. • Genetic testing is now available for Birt-Hogg-Dube syndrome .

12. Secondary spontaneous pneumothoraces (SSP • occur in the presence of lung disease, primarily in the presence of chronic obstructive pulmonary disease (COPD).

13. Other diseases that may be present when secondary spontaneous pneumothoraces occur include tuberculosis,sarcoidosis, cystic fibrosis, malignancy, and idiopathic pulmonary fibrosis.

14. Pneumocystis jiroveci(previously known asPneumocystis carinii(pneumonia [PCP]) was a common cause of secondary spontaneous pneumothorax in patients with AIDS during the last decade.

15. With the advent of highly active antiretroviral therapy (HAART) and widespread use of trimethoprim-sulfamethoxazole prophylaxis, the incidence of PCP and associated SSP has significantly declined.

16. Traumatic pneumothoraces • Traumatic pneumothoraces can result from both penetrating and nonpenetrating lung injuries. • Traumatic pneumothoraces can create a 1-way valve in the pleural space, only letting in air without escape, and can lead to a tension pneumothorax.

17. Iatrogenic pneumothorax • Iatrogenic pneumothorax is a complication of medical or surgical procedures. • It most commonly results from transthoracic needle aspiration.

18. Other procedures commonly causing iatrogenic pneumothorax are therapeutic thoracentesis, pleural biopsy, central venous catheter insertion.

19. Tension pneumothorax • Tension pneumothorax typically occurs in the intensive care setting in patients who are ventilated. • With air trapping in the pleural space, positive pressure rises

20. This pressure compresses the mediastinum, decreasing venous return to the heart and reducing cardiac output.

21. In addition, owing to ipsilateral lung collapse and contralateral lung compression, gas exchange is compromised, leading to hypoxemia.

22. Pathophysiology • If air enters the pleural cavity, either from the outside (open pneumothorax) or from the lung (closed pneumothorax), the lung collapses and it becomes mechanically impossible for the injured person to breathe, even with an openairway.

23. If a piece of tissue forms a one-way valve that allows air to enter the pleural cavity from the lung but not to escape, overpressure can build up with every breath; this is known astension pneumothorax.

24. It may lead to severe shortness of breath as well as circulatory collapse, both life-threatening conditions. • This condition requires urgent intervention.

25. Differential Diagnosis • Emphysema • Acute Myocardial Infarction

26. DIAGNOSIS • Symptom • physical examination • imaging studies • lab studies

27. Symptoms • Symptoms are present in 64% of patients. • Acute onset of chest pain - Severe and/or stabbing pain, radiating to ipsilateral shoulder and increasing with inspiration (pleuritic). • Sudden shortness of breath.

28. Anxiety, cough, and vague presenting symptoms (eg, general malaise, fatigue) are less commonly observed.

29. Dyspnea tends to be more severe with secondary spontaneous pneumothoraces because of decreased lung reserve.

30. PhysicaL • General appearance • Diaphoretic • Splinting chest wall to relieve pleuritic pain • Cyanotic (with tension pneumothoraces).

31. Vital signs • Tachypnea • Tachycardia (most common finding) - Pulsus paradoxus • Hypotension (often with tension pneumothorax(

32. Asymmetric lung expansion. • Mediastinal and tracheal shift to the contralateral side with a large tension pneumothorax. • Distant or absent breath.

33. Distant or absent breath sounds. • Hyperresonance on percussion. • Decreased tactile fremitus. • Cardiovascular - Jugular venous distension (tension pneumothorax) • Neurologic - Altered mental status.

34. Lab Studies • Arterial blood gas • In patients with severe underlying lung disease and in those with persistent respiratory distress despite treatment. • Hypoxemia occurs with increased alveolar-arterial oxygen tension gradient.

35. Hypoxemia tends to be more severe in patients with secondary spontaneous pneumothoraces.

36. Imaging Studies • Chest radiograph • CT scan • Ultrasonograph

37. Chest radiograph • A linear shadow of visceral pleura with lack of lung markings peripheral to the shadow may be observed, indicating collapsed lung.

41. In supine patients, deep sulcus sign with radiolucency along costophrenic sulcus may help to identify occult pneumothorax.

43. Mediastinal shift toward the contralateral lung may also be apparent. • Small pleural effusions commonly are present and increase in size if the pneumothorax does not reexpand.

45. Method to estimate the fractional size of pneumothorax: • Calculate the ratio of the transverse radius of the pneumothorax (cubed) to the transverse radius of the hemithorax (cubed) • To express the pneumothorax size as a percentage, multiply the fractional size by 100.

47. CT SCAN • CT is not routinely recommended for the evaluation of spontaneous pneumothorax. • However because of the inherent superiority of CT scans to visualize the details of lung parenchyma and pleura.

48. CT scans are widely used in actual clinical practice to assess the possibility of associated concurrent pulmonary disease.

49. CT scan is not recommended for routine use but can help to accomplish the following: • Distinguish between a large bulla and a pneumothorax. • Indicate underlying emphysema or emphysemalike changes.

50. Determine the exact size of the pneumothorax, especially if it is small. • Confirm the diagnosis of pneumothorax in patients with head trauma who are mechanically ventilated.