23. Pneumothorax and pleural fluid: causes, types, diagnosis, and treatment

Question 1

Combined diagnosis of subtypes and management

What to do if we suspect Pneumothorax in a patient

We suspect pneumothorax based on respiratory distress and dyspnea presentation signs + Physical exam findings of decreased or absent tactile fremitus, low or absent breath sounds on auscultation, percussion is hyper resonant

Answer 1

Any suspection of pneumothorax must follow quick evaluation to rule out tension pneumothorax which is life thretening
- If trauma patient ==> ATLS protocol
- Not trauma patient ==> provide respiratory support [as they present with respiratory distress/dyspnea signs], 100% O2 supplementation, upright position, Analgesia/NSAIDS
- Patient has > 24 breaths per min AND/OR below 90% SpO2 AND/OR HR below 60 or above 120 AND/OR SBP below 90 mmHg AND/OR speaking in incomplete sentences ==> Unstable patient
- If patient has none of the above, patient is Stable

Unstable Patient with suspected pneumothorax:
- Trachea displacement, distended neck veins, Pulsus paradoxus ==> Emergency Chest tube placement/Needle thoracostomy
- Not above ==> STAT bedside US or portable CXR
- If CXR or bedside US shows pneumothorax ==> Emergency chest tube placement

Stable Patient with suspected pneumothorax:
- CXR/Chest CT/Lung US
- If bilateral pneumothorax present ==> Chest tube placement
- If patient > 50 years old with significant smoking history AND/OR exam or image evidence of lung disease ==> Secondary Spontaneous pneumothorax
- If patient not above ==> Primary Spontaneous pneumothorax

Secondary Spontaneous pneumothorax management is Chest Tube placement [admission to ICU based on Apex-to-Cupula length > 3cms]

Primary Spontaneous pneumothorax management is also based on Apex-to-cupula length but also presence/absence of dyspnea on normal air with mobilization
- Apex to cupula length < 3 cms AND/OR no dyspnea ==> Conservative management and observation post management, 3-6 hours with CXR for progression
- Apex to cupula length > 3 cms AND/OR dyspnea signs ==> Needle thoracostomy, observation post management and CXR for progression
- Chest tube if Needle thoracostomy unsuccessful
- In both cases, progression prompts Chest Tube placement

Question 2

3 different types of Pneumothorax

Answer 2

• Primary Spontaneous Pneumothorax [No apparent underlying reason other than smoking history and family history, male sex]
• Secondary Spontaneous Pneumothorax [complication of underlying disease - COPD, infections, Marfan syndrome, Malignancy, Cystic Fibrosis]
• Closed Pneumothorax [air communication/movement between Lung and pleural cavity, blunt traumas]
• Open Pneumothorax [air communication/movement between Pleural cavity and outisde, penetrating trauma]
• Tension Pneumothorax [one-way valve between lung and pleural cavity OR pleural cavity and outside, where air gets inside pleural cavity but cannot leave

Spontaneous pneumothorax - rupture of blebs or bullae
Closed and Open Pneumothorax - trauma induced

Question 3

Pneumonic

Signs and Symptoms of Pneumothorax

Answer 3

P-THORAX
- Pleuritic Pain
- Tracheal deviation
- Hyperresonance on percussion
- Onset is sudden
- Reduced breath sounds on auscultation and Dyspnea
- Absent tactile fremitus
- Xray shows lung collapse signs

Hyperresonance is not always present in actual setting, more textbook

Question 4

Specific symptoms of PTX in addition to P-THORAX

Answer 4

• Severe Respiratory distress [cyanosis, increased breathing work, restlessness, diaphoresis]
• Reduced chest expansion on affected side
• Hemodynamic instability [Tachypnea, tachycardia, low BP, Pulsus paradoxus]
• Neck vein distension [although it is a textbook case and not always present in real situations]

Question 5

and causes, quality of fluid

Types of Pleural fluid that can be found

Answer 5

• Exudative pleural fluid [due to increased capillary permeability - infections, malignancies, PE, injuries, post CABG procedure; high in protein and specific gravity]
• Transudative pleural fluid [due to increased hydrostatic pressure - CHF, PE, PAH; due to decreased oncotic pressure - chronic kidney and liver diseases; low in protein and specific gravity]
• Hemothorax [presence of RBCs and hematocrit; blood accumulation not related to trauma; hypotension and tachycardia; malignancies, coagulation disorders, PE with infarction, necrotizing infections, Bullous emphysema]
• Empyema [Pus in pleural cavity from pneumonia; low pH and low glucose from bacterial growth]
• Chylothorax [lymphatic fluid in pleural cavity from blockage like cancers, trauma, congenital anomalies like lymphangiectasis; cloudy and milky exudate]
• Malignant effusion [maligancy of parietal pleura or metastasis from other sources into lung/pleura; increased plasma proteins, blood cells and tumour cells, cell rich exudative fluid with abnormal cytology]

Question 6

Diagnosis of Pleural Effusion

Answer 6

• CXR/CT/US will show signs of pleural effusion
• Specific cause will need thoracocentesis to analyse fluid quality
• CXR signs: homogenous shadowing, diaphragm and recess not fully visible, no air-fluid level
• US signs: hypoechoic or anechoic collections, can detect amounts as low as 20ml in recessess

Question 7

Treatment of Pleural fluid

Answer 7

Depends on specific cause of fluid
- Chest tube to drain fluid for infectious reasons/malignancy and Hemothorax
- Treatment of underlying cause [antibiotics, heart symptoms management, cancer therapy, etc]