Pneumothorax

Introduction

Pneumothorax is the presence of air or gas in the pleural cavity which can impair oxygenation and/or ventilation.

This occurs in apparently normal lung or in the presence of an underlying lung disease.

Clinical results are dependent on the degree of collapse of the lung on the affected side.

Classes of pneumothorax

Pneumothorax is classified as:

1. Spontaneous pneumothorax which
   develop without preceding trauma (e.g. Primary and Secondary)
2. Traumatic pneumothorax which develop as a result of direct or indirect trauma to the chest, including diagnostic or therapeutic maneuvers (latrogenic Pneumothorax).

Primary Spontaneous Pneumothorax (PSP):

• Presents in an otherwise healthy individual with no underlying lung disease.
• Occurs in people aged 20-30 years, with a peak incidence in the early twenties.
• Rarely observed in people older than 40 years.

Secondary Spontaneous Pneumothorax (SSP):

Complicates an underlying lung disease like pulmonary infections e.g.

Tuberculosis, pneumocystis pneumonia, bacterial pneumonia or pulmonary airway disease e.g.COPD especially emphysema, acute severe asthma, and cystic fibrosis
Occurs more frequently in patients aged 60-65  yrs

Catamenia Pneumothorax:

• Recurrent pneumothorax associated with menstruation
• Respiratory Symptoms occur within 24-48hrs. of menstruation in women aged 30-40 years.
• Mostly right-side and associated with parity Pelvic endometriosis may be demonstrated in up to one-third of patients.

Tension Pneumothorax

Tension pneumothorax is a life threatening condition and develops when air is trapped in the pleural cavity under positive pressure.

Displaces mediastinal structures and Complicates approximately 1-2% of the cases of spontaneous pneumothorax.

Clinical features of pneumothorax

Varies widely from being asymptomatic to life threatening respiratory distress.

Symptoms of pneumothorax

The following are the symptoms of pneumothorax:

• Acute onset of chest pain (sharp and stabbing) worse on inspiration
• Shortness of breath
• Sweating
• Fainting
• Anxiety Cough
• History of previous Pneumothorax Acute epigastric pain

Signs of pneumothorax

Respiratory system

• Dyspnea
• Tachypnoea (or bradypnoea as a preterminal event)
• Tracheal deviation to contra-lateral side
• Decreased chest expansion
• Decreased tactile fremitus
• Normal or hyper-resonant chest wall percussion notes
• Decreased breath sounds on the affected side

Central nervous system

• Altered consciousness
• Anxiety
• Syncope

Cardiovascular system

• Tachycardia
• Pulsus paradoxus
• Hypotension
• Raised jugular venous pressure

Differential diagnosis

• Acute coronary syndrome
• Acute respiratory distress syndrome
• Aortic dissection
• Congestive cardiac failure and
• pulmonary edema
• Esophageal rupture and tears
• Myocarditis and cardiac tamponade
• Pulmonary Embolism
• Rib fracture

Complications of pneumothorax

1. Failure to re-expand
2. Recurrence
3. Haemopneumothorax
4. Pyopneumothorax
5. Re-expansion pulmonary edema.
6. Respiratory failure

Investigations

• Chest Computer Tomography (CT)
• Arterial Blood Gas Analysis
• Chest Radiography
• Chest ultrasonography

Goals of Treatment:

• Relieve the Pneumothorax
• Prevent recurrence.

Modality of treatment depends on clinical presentation and aetiology.

Patients with PSP or SSP and significant
breathlessness associated with any size of Pneumothorax should undergo active
intervention on admission (Tension
pneumothorax)

Management of PSP

• Observation is the treatment of
  choice for small PSP without significant  breathlessness.
• Selected asymptomatic patients with a large PSP may be managed by observation alone for the natural tendency of the gases in pleural space is to be reabsorbed.
• Patients with a small PSP without breathlessness should be considered for discharge with early outpatient review.
• These patients should also receive clear written advice to return in the event of worsening breathlessness.

Drainage of Pneumothorax

• Needle aspiration (NA) using size 14-16G needle drains.
• NA should not be repeated unless there were technical difficulties.
• Following failure of NA, small core (<14F) chest drain insertion is
  recommended.
• Large-bore chest drains are not needed for pneumothorax.

Suction

• Suction should not be routinely used
• Caution is required because of the risk of re-expansion pulmonary edema
• High volume low-pressure suction
  systems are recommended

Specialist referral

• Referral to a respiratory physician should be made within 24hours of admission.
• Complex drain management is best
  effected in areas where specialist medical and nursing expertise are available.

Management of SSP

• All patients with SSP should be admitted to hospital for at least 24hours and receive supplemental oxygen.
• Most patient will require the insertion of a small-bore chest drain.
• All patient will require early referral to a chest physician to treat underlying cause.
• Those with a persistent air leak should be discussed with a thoracic surgeon at 48hours on admission.

SSP patient who are unfit for surgery

• Medical pleurodesis may be appropriate for inoperable patients
  Patients with SSP can be considered for ambulatory management with a Heimlich valve

Discharge and follow-up

• Patients should be advised to return to hospital if increasing breathlessness develops.
• All patients should be followed up by a respiratory physicians until full resolution.
• Air travel should be avoided until full  resolution.
• Diving should be permanently avoidedbunless the patient has undergone bilateral pleurotomy and has normal lung function and chest CT scan post operatively.

Medical chemical pleurodesis

• Chemical pleurodesis can control
  difficult or recurrent Pneumothoraces but, since surgical options are more effective, it should only be used if avpatient is either unwilling or unable tovundergo surgery.
• Chemical pleurodesis for pneunothorax should only be performed by a respiratory specialist using 5g sterile talc in Normal saline.

Referral to thoracic surgeons

• In cases of persistent air leak or failure of the lung to re-expand, an early (3-5 days) thoracic surgical option should be sought.

Surgical strategies:

• Open thoracostomy
• video Assisted Thoracoscopic (VATS)

Tension Pneumothorax treatment

• Tension Pneumothorax is a medical
  emergency
• Treatment is with oxygen and emergency needle decompression at the second intercostal space.
• Pleurodesis with 5% talc in Normal saline is done when all the air is out.