Case Files Surgery, (LANGE Case Files) 4th Ed.

SECTION II. Clinical Cases

CASE 22

A 33-year-old man presents with a sudden onset of left chest pain and shortness of breath that occurred while he was working in his yard. The patient denies any trauma to his chest and any cough or other respiratory symptoms prior to the onset of pain. His past medical history is unremarkable. He takes no medications. He consumes one pack of cigarettes a day and two to three beers a day. On physical examination he appears anxious. His temperature is normal, his pulse rate 110 beats/min, his blood pressure 124/80 mm Hg, and his respiratory rate 28 breaths/min. The pulmonary examination reveals diminished breath sounds on the left and normal breath sounds on the right. A cardiac examination demonstrates no murmurs or gallops. Results from the abdominal and extremity examinations are unremarkable. The laboratory examination reveals a normal complete blood count and normal serum electrolyte levels. The chest radiograph shows a 50% left pneumothorax, without effusion or pulmonary lesions.

Images What is your next step?

Images What are the risk factors for this condition?

ANSWERS TO CASE 22: Pneumothorax (Spontaneous)

Summary: An otherwise healthy 33-year-old man presents with a large primary spontaneous pneumothorax.

• Next step: Perform either tube thoracostomy or needle aspiration to allow reexpansion of the left lung.

• Risk factors for this condition: Primary spontaneous pneumothorax is caused by the rupture of subpleural blebs. Secondary spontaneous pneumothorax may be caused by bullous emphysematous disease, cystic fibrosis, primary and secondary cancers, and necrotizing infections with organisms such as Pneumocystis jiroveci (formerly known as P carinii).

ANALYSIS

Objectives

1. Learn to distinguish between primary and secondary spontaneous pneumothorax.

2. Learn the treatment and diagnostic strategies for patients presenting with spontaneous pneumothorax.

Considerations

The patient is a young man, the type of individual most likely to develop spontaneous pneumothorax. The most common cause is the rupture of a subpleural bleb. This patient does not have any risk factors for secondary causes of spontaneous pneumothorax such as malignancy, tuberculosis, sarcoidosis, or chronic obstructive pulmonary disease. The best management would be insertion of a chest tube or needle aspiration to allow for reexpansion of the lung.

APPROACH TO: Spontaneous Pneumothorax

DEFINITIONS

PNEUMOTHORAX: Condition whereby air enters the pleural space, thus preventing expansion of the lung parenchyma.

TENSION PNEUMOTHORAX: Caused by a flap-valve effect such that air enters the pleural space but cannot exit until the pleural pressure is so great that it prevents blood from entering the chest.

OPEN PNEUMOTHORAX: Injury to the full thickness of the chest wall such that the negative intrapleural pressure results in air being sucked directly through the chest wall defect, preventing air from being taken in through the trachea; it requires a mechanical covering over the chest wound.

FLAIL CHEST: Injury to multiple ribs leading to a paradoxical inward movement of the affected chest region on inspiratory effort, resulting in little air movement. Concerns in patients with this condition are lung dysfunction associated with injuries to the lungs under the flail segment and the development of atelectasis secondary to pain from the rib fractures.

TUBE THORACOSTOMY: Placement of a catheter (chest tube) into the pleural space to evacuate air, blood, or fluid to permit better ventilation.

CLINICAL APPROACH

The initial management of pneumothorax requires reexpansion of the lung. This often requires tube thoracostomy, but thoracentesis or pleural catheter drainage can be attempted for smaller pneumothoraces (<30% of the width of the hemithorax). Small asymptomatic pneumothoraces (<15% of the width of the hemithorax) can be initially observed with serial chest radiographs. If the pneumothorax does not improve or the patient develops symptoms (chest pain, dyspnea), tube thoracostomy will be required.

Spontaneous pneumothorax can be classified as either primary or secondary. Primary pneumothorax is usually caused by the rupture of subpleural pulmonary blebs. This condition is more commonly observed in young men (15-35 years of age) who are smokers, but without other risk factors for spontaneous pneumothorax. Secondary spontaneous pneumothorax results from an acquired process and is most commonly seen in older (>50 years) patients with chronic obstructive pulmonary disease. These patients may present with severe respiratory difficulty because of the already present diffuse lung disease. Other reasons for secondary spontaneous pneumothorax include malignancy, infection (tuberculosis, P jiroveci), catamenial (pulmonary endometriosis, occurring usually with menstruation), asthma, sarcoidosis, and cystic fibrosis. For management of these problems see Figure 22–1.

Images

Figure 22–1. Algorithm for the management of spontaneous pneumothorax. PCP, Pneumocystis jiroveci pneumonia; TB, tuberculosis; VATS, video-assisted thoracoscopy.

Chest tube management is sufficient treatment for most cases of spontaneous pneumothorax, with 15% to 20% of the patients requiring subsequent surgical intervention. Surgery is indicated for first-time spontaneous pneumothorax when there is persistent air leakage (3-5 days), when the lung fails to reexpand, in patients who are at high risk for recurrence (bilateral pneumothoraces, a previous history of contralateral pneumothorax, significant bullous disease on radiographs), in patients who have limited access to medical care (those living in remote areas), and in patients whose occupation produces an increased risk (scuba divers, pilots).

The recurrence rate for spontaneous pneumothorax is 30% after the first occurrence, 50% after the second, and 80% after the third. Therefore, immediate surgical intervention is indicated after the second recurrence. Surgical treatment in these patients consists of pleurodesis and resection of the blebs by either thoracoscopic approach or thoracotomy.

COMPREHENSION QUESTIONS

22.1 A patient is seen by the pulmonologist for recurrent spontaneous pneumothorax. Which of the following is the most likely risk factor for this condition?

A. Female gender

B. Age 55 to 70 years

C. Tall, thin physique

D. History of tuberculosis

E. Upper respiratory tract infections

22.2 The patient in Question 22.1 asks about recurrence risk. Which of the following factors is most predictive of the recurrence of pneumothorax?

A. Patient’s occupation

B. Location of blebs

C. Presence of chronic obstructive pulmonary disease

D. The effectiveness of the initial treatment

E. Number of previous episodes of pneumothorax

22.3 A 33-year-old woman who underwent multiple enterotomies for penetrating abdominal trauma has a subclavian central line placed and subsequently develops “air hunger.” Which of the following is the most likely etiology?

A. Acute psychosis

B. Panic disorder

C. Hemothorax

D. Pneumothorax

E. Pulmonary embolism

22.4 Which of the following presentations is most consistent with left tension pneumothorax?

A. Hypotension, distended neck veins, midline trachea, and muffled heart sounds

B. Hypotension, open wound measuring 10 × 10 cm in the left lateral chest

C. Hypotension, diminished breath sounds on left, tracheal deviation to the right, and chest x-ray demonstration of opacification of the left hemithorax

D. Diminished left breath sounds, tracheal deviation to the right

E. Diminished left breath sounds, tracheal deviation to the left

22.5 An emergency center physician is assessing a 38-year-old man who has respiratory complaints. The physician’s differential diagnosis is pleural effusion versus pneumothorax. Which one of the following findings is more likely to be found in pleural effusion and not pneumothorax?

A. Respiratory rate of 33 breaths/min

B. Agitation

C. Somnolence

D. Dullness to percussion over the chest wall on the affected side

E. Cough

ANSWERS

22.1 C. Spontaneous pneumothorax occurs more commonly in young men who are thin and tall and in smokers. These are processes that are primary events, not due to disease processes.

22.2 E. The number of prior episodes of pneumothorax is more predictive of a recurrence, with an 80% recurrence rate after three previous episodes.

22.3 D. A fairly common complication of the placement of central venous catheters is pneumothorax.

22.4 D. Diminished breath sound on the left and tracheal deviation to the right. Findings described in “A” are compatible with cardiac tamponade. Findings in “B” are compatible with an open pneumothorax. Findings in “C” are compatible with left tension hemothorax or hydrothorax leading to mediastinal structures shifting to the right. The findings described in “E” are compatible with left bronchial obstruction, resulting in volume loss and hypoventilation on the left.

22.5 D. Dullness to percussion of chest wall on the affected side is not a finding consistent with pneumothorax. Tachypnea can be associated with the increased work of breathing associated with pneumothorax. Agitation is a finding that could be produced by the hypoxemia associated pneumothorax. Somnolence can develop in the setting of profound hypoxia just prior to the onset of respiratory arrest. Cough could be associated with lung expansion during the treatment of a pneumothorax or airway obstructive diseases.

CLINICAL PEARLS

Images Although most cases of pneumothorax can be managed with a tube thoracostomy, aggressive surgical intervention is indicated for cases where there is a high risk of recurrence.

Images The general therapeutic goal is to address the underlying problem (blebs, infection, etc) and to achieve pleural apposition (reexpansion of the lung).

Images Failure to achieve pleural apposition or persistent air leakage requires surgical intervention.

REFERENCES

Nason KS, Maddaus MA, Luketich JD. Chest wall, lung, mediastinum, and pleura. In: Brunicardi FC, Andersen DK, Billiar TR, et al, eds. Schwartz’s Principles of Surgery. 9th ed. New York, NY: McGraw-Hill; 2010:513-590.

Todd SR, Vercruysse GA, Moore FA. Pneumothorax. In: Cameron JL, ed. Current Surgical Therapy. 9th ed. Philadelphia, PA: Mosby Elsevier; 2008:702-705.