Spontaneous pneumothorax
"Spontaneous" essentially refers to all pneumothoraces of "non-traumatic" etiologies
Background
- Primary Pneumothorax
- Marfan's, Ehlers-Danlos, alpha-1-antitrypsin deficiency, homocystinuria
- No underlying pulmonary disease
- Secondary Pneumothorax
- With underlying pulmonary disease
- bullae/blebs, emphysema, cystic fibrosis, PJP pneumonia, lung abscess, tuberculosis, neoplasm, catamenial
- Worse prognosis
- With underlying pulmonary disease
Secondary Causes
- Smoking (90%)
- COPD
- Asthma
- Cystic fibrosis
- Necrotizing pneumonia
- Lung abscess
- PCP pneumonia
- TB
- Neoplasm
- Interstitial lung disease
- Connective tissue disease
- Pulmonary infarct
- Catamenial pneumothorax
Clinical Features
- Sudden onset pleuritic chest pain evolving to dull constant ache over days
- Most often occurs at rest, not during exertion
- Tachypnea, hypoxemia, increased work of breathing
- Reduced ipsilateral lung excursion
- Hypotension→ tension pneumothorax
Differential Diagnosis
Pneumothorax Types
Acute dyspnea
Emergent
- Pulmonary
- Airway obstruction
- Anaphylaxis
- Angioedema
- Aspiration
- Asthma
- Cor pulmonale
- Inhalation exposure
- Noncardiogenic pulmonary edema
- Pneumonia
- Pneumocystis Pneumonia (PCP)
- Pulmonary embolism
- Pulmonary hypertension
- Tension pneumothorax
- Idiopathic pulmonary fibrosis acute exacerbation
- Cystic fibrosis exacerbation
- Cardiac
- Other Associated with Normal/↑ Respiratory Effort
- Other Associated with ↓ Respiratory Effort
Non-Emergent
- ALS
- Ascites
- Uncorrected ASD
- Congenital heart disease
- COPD exacerbation
- Fever
- Hyperventilation
- Interstitial lung disease
- Neoplasm
- Obesity
- Panic attack
- Pleural effusion
- Polymyositis
- Porphyria
- Pregnancy
- Rib fracture
- Spontaneous pneumothorax
- Thyroid Disease
- URI
Evaluation
Clinically Stable
Defined as having all of the following:
- Resp rate < 24
- Heart rate 60-120 beats per minute
- Normal BP
- SaO2 >90% on room air and patient can speak in whole sentences
Workup
- CXR
- Displaced visceral pleural line without lung markings between pleural line and chest wall
- Upright is best
- Expiratory films DO NOT improve accuracy[1]
- Lateral decubitus films with suspected side up do increase sensitivity. Good approach in pediatrics to avoid CT
- Supine CXR = deep sulcus sign
- CT Chest
- Very sensitive and specific
Lung ultrasound of pneumothorax
- No lung sliding seen (not specific for pneumothorax)
- May also identify "lung point": distinct point where you no longer see lung sliding (pathognomonic)
- Absence of lung sliding WITHOUT lung point could represent apnea or right mainstem intubation
- Evaluate other intercostal spaces because pneumothorax may only be seen in least dependent area of thorax
- NO comet tail artifact
- Bar Code appearance/"Stratosphere" sign on M-mode (absence of "seashore" waves)
- Ultrasound has greater sensitivity than chest x-ray for pneumothorax in trauma patients [2]
Estimating Pneumothorax Size
- On a conventional, upright posterior-anterior chest radiograph:
- Very small: <1 cm interpleural distance (confined to upper 1/3 of chest) OR only seen on CT
- Small: ≤3cm lung apex to cupola (chest wall apex) on CXR
- Large: >3cm lung apex to cupola (chest wall apex) on CXR
- 3cm apex to cupola measurement is roughly equivalent to 2cm interpleural distance (at the level of the hilum)
- Both roughly correlate with a 50% pneumothorax by volume
Management[3]
Supplemental oxygen (non-rebreather mask) initially for all
Unstable
- Needle decompression followed by chest tube insertion
- ATLS guidelines recommend 5cm angiocath at 2nd intercostal space at the mid-clavicular line
- More recent evidence shows higher success rates with 4th/5th intercostal space at the anterior or mid-axillary line
Primary Spontaneous Pneumothorax (Stable)
First Episode
- Small AND asymptomatic (no dyspnea)
- Observe on supplemental oxygen (non-rebreather mask) for 6 hours; repeat CXR and discharge if no progression; return in 24 hours for a recheck
- Large OR symptomatic (e.g. dyspnea)
- Aspiration (see below)
- If fail, admit with chest tube to suction for thoracoscopy (VATS)^
- Aspiration (see below)
- British Thoracic Society Protocol[4]
- 2020 study supports conservative therapy vs chest tube. [5] however there are issues with study including “significant drop out rate, the relatively large number of protocol violations, the large inferiority margins and the short intervention time.”[6]
- Inclusion criteria
- 14 to 50 years of age
- unilateral primary spontaneous pneumothorax of 32% or more on chest radiography according to the Collins method (sum of interpleural distances, >6 cm)
- Exclusion criteria [7]
- Secondary pneumothorax, defined as pneumothorax occurring in the setting of acute trauma (including iatrogenic) or underlying lung disease including but not limited to COPD, pulmonary fibrosis, TB, cystic fibrosis, lung cancer and asthma that requires regular preventative medication or has been symptomatic within the last two years
- Previous spontaneous pneumothorax on the same side 3. Coexistent haemothorax (i.e. spontaneous haemopneumothorax)
- Bilateral pneumothorax
- Clinical instability suggesting tension pneumothorax; respiratory distress persisting despite oxygen and parenteral narcotic analgesia (RR >30/min or SpO2 <90%), SBP <90 mmHg, HR greater than or equal to SBP.
- Pregnancy at time of enrolment
- Social circumstances whereby the patient either does not have adequate support after discharge to re-attend hospital if required, or is unlikely to present for study follow up.
- Air travel within the next 12 weeks if this cannot be deferred should the pneumothorax be slow to resolve"
- Observed for a minimum of 4 hours then repeat chest X-ray.
- Discharge if no supplementary oxygen and walking comfortably,
- Chest tubes placed if:
- clinically significant symptoms persisted despite adequate analgesia
- chest pain or dyspnea prevented mobilization
- patient was unwilling to continue with conservative treatment
- the patient’s condition became physiologically unstable (systolic blood pressure of <90 mm Hg, heart rate in beats per minute greater than or equal to systolic blood pressure in millimeters of mercury, respiratory rate of >30 breaths per minute, or Spo2 of <90% while the patient was breathing ambient air)
- repeat chest radiograph showed an enlarging pneumothorax along with physiological instability.
- Inclusion criteria
Recurrent OR Hemopneumothorax
- Admit with chest tube for thoracoscopy (VATS)^
^If thoracoscopy (VATS) is not readily available, chemical pleurodesis through the chest tube
Secondary Pneumothorax (Stable)
- Asymptomatic AND very small (<1 cm interpleural distance)
- Observation with supplemental oxygen; repeat CXR in 12-24 hours
- Asymptomatic AND small
- Chest tube (some centers may choose needle aspiration under ultrasound guidance)
- Observation alone associated with some mortality
- Symptomatic OR large OR bilateral
- Admit all secondary pneumothoraxes
Needle Aspiration of Pneumothorax
- Use thoracentesis or "pig-tail" kit, if available
- Place in 2nd IC space in midclavicular line or 4th/5th IC space in anterior axillary line
- Withdraw air with syringe until no more can be aspirated
- Assume a persistent air leak (failure) if no resistance after 4 liters of air has been aspirated AND the lung has not expanded
- Once no further air can be aspirated:
- Option 1
- Place closed stopcock and secure catheter to the chest wall
- Obtain CXR four hours later
- If adequate lung expansion has occurred, remove catheter
- Following another two hours of observation, obtain another CXR
- If the lung remains expanded, may discharge patient
- Option 2
- Leave catheter in place
- Attached a Heimlich (one-way) valve
- May discharge with follow-up within two days
- Option 1
- If 2.5 L of air has been aspirated, and a significant PTX remains, tube thoracostomy is indicated
- NEJM video on needle aspiration of pneumothorax.
Adult Chest Tube Sizes
Chest Tube Size | Type of Patient | Underlying Causes |
Small (8-14 Fr) |
|
|
Medium (20-28 Fr) |
|
|
Large (36-40 Fr) |
|
Disposition
Primary
- See Management section
Secondary
- All admitted (even if small and clinically stable)
Special Instructions
Flying
- Can consider flying 2 weeks after full resolution of traumatic pneumothroax[3]
Complications
See Also
References
- ↑ Eur Respir J. 1996 Mar;9(3):406-9
- ↑ Nagarsheth K, Kurek S. Ultrasound detection of pneumothorax compared with chest X-ray and computed tomography scan. Am Surg. 2011 Apr;77(4):480-4. PMID: 21679560.
- ↑ 3.0 3.1 "Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010" British Thoracic Society Guidelines. Thorax 2010;65:ii18-ii31 doi:10.1136/thx.2010.136986 PDF
- ↑ Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010 https://thorax.bmj.com/content/65/Suppl_2/ii18
- ↑ EBQ:Conservative versus interventional treatment for spontaneous pneumothorax
- ↑ https://www.stemlynsblog.org/jc-conservative-management-of-pneumothoraces/
- ↑ https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12611000184976
- ↑ Inaba Et. al J Trauma Acute Care Surg. 2012 Feb;72(2):422-7.
- ↑ Advanced Trauma Life Support® Update 2019: Management and Applications for Adults and Special Populations.