You have a new patient!
A 24-year-old male with no significant medical history presents to the emergency department for shortness of breath for two days duration. The symptom is associated with left-sided pleuritic chest pain. He denies fever, cough, constitutional symptoms, or trauma. He is an active smoker.
On assessment, the patient was mildly tachypneic and well-perfused. Auscultation reveals reduced breath sounds over the left lung. There is hyperresonance on percussion over the left lung as well. There is no tracheal deviation. Vital signs are as follows:
Blood pressure – 108/75 mmHg
Pulse rate – 74/minute
Respiratory rate – 24/minute
Oxygen saturation – 98% under room air
Temperature – 36.8o Celcius
Pain score – 4/10
What do you need to know?
Importance
Pneumothorax is defined as the presence of air in the pleural space. Pneumothoraces can be further divided into primary spontaneous pneumothorax (PSP), which occurs in patients spontaneously without any apparent underlying pleural disease, or secondary pneumothorax in patients with underlying diseases such as tuberculosis and lung malignancy [1,2]. Iatrogenic pneumothorax can also occur due to procedures such as thoracocentesis and central venous line insertion [2].
Identifying a pneumothorax is important, as a delay in management can lead to hemodynamic instability. In unstable patients with respiratory and circulatory compromise, the differential diagnosis of tension pneumothorax must be excluded.
Epidemiology
The incidence of primary spontaneous pneumothorax varies significantly between genders. Among the male population, it is reported to occur at a rate of 7.4 to 18 cases per 100,000 individuals annually. In contrast, the incidence in the female population is comparatively lower, ranging from 1.2 to 6 cases per 100,000 individuals per year [1].
Pathophysiology
Under normal circumstances, the pressure in the pleural space is negative compared to atmospheric pressure. This negative pressure is generated due to the opposing forces between the lung’s tendency to collapse because of elastic recoil and the outward expansion of the chest wall [2]. When there is communication between the alveoli and pleural space, the introduction of air alters the gradient until pressure equilibrium is reached, resulting in partial or total lung collapse. Tension pneumothorax occurs when inhaled air accumulates in the pleural space but cannot exit due to a one-way valve mechanism [2].
This condition leads to the clinical presentation of dyspnoea and chest pain. In tension pneumothorax, the increased intrathoracic pressure can decrease venous return and restrict lung function, ultimately leading to shock and hypoxia [2].
Medical History
In patients with a primary spontaneous pneumothorax, mild symptoms may be reported as they often tolerate the consequences of a pneumothorax better compared to those with underlying respiratory problems. The most common symptoms are chest pain and shortness of breath [3].
When inquiring about pain, the SOCRATES mnemonic may be helpful:
- Site: Pain on the affected side
- Onset: Usually, sudden onset of pain
- Character: Typically described as sharp
- Radiation: Radiation to the ipsilateral shoulder
- Associated symptoms: Breathlessness
- Time: Although the onset of pain may be acute, patients may present late if they can tolerate symptoms
- Exacerbating/relieving factors: Pleurisy (pain worsening on inspiration) is common
- Severity: Quantify the pain score when possible
Asking about risk factors may also help in strengthening the diagnosis of pneumothorax, including cigarette smoking, male gender, mitral valve prolapse, Marfan’s syndrome, and changes in ambient pressure. It is also important to ask about the history of trauma and recent medical procedures. Family history may be relevant as there may be a genetic predisposition to the condition.
Finally, enquire about the presence of a chronic cough and constitutional symptoms such as weight loss, loss of appetite, and fatigue to help ascertain whether the pneumothorax may be due to an underlying pleural disease.
Physical Examination
When assessing a patient with a potential pneumothorax, examine systematically using the ABC approach to avoid missing potential signs, especially those of a tension pneumothorax, as this condition requires immediate intervention [4].
- Airway: Tracheal deviation is a late sign of tension pneumothorax, though it is not always indicative.
- Breathing: Signs include tachypnoea, hypoxia, unequal chest rise, subcutaneous emphysema, hyperresonance, and absent or reduced breath sounds.
- Circulation: Hypotension (a key sign of tension pneumothorax), tachycardia, and cold peripheries may be present.
Differential Diagnoses
The patients present mostly with shortness of breath (SOB). Therefore, pulmonary, cardiac and other causes of SOB should be considered first.
- Pulmonary
- Airway obstruction
- PE
- Pulmonary edema
- Anaphylaxis
- Asthma
- Cor pulmonale
- Aspiration
- Cardiac
- MI
- Tamponade
- Pericarditis
- Others
- Esophageal rupture
- Toxin ingestion
- Epiglottitis
- Anemia
Acing Diagnostic Testing
The diagnosis of spontaneous pneumothorax is confirmed by imaging. After the diagnosis is confirmed, the clinical evaluation, including the history obtained and the patient’s clinical condition, should determine the management strategy.
Chest X-ray
The standard view is the erect PA chest x-ray. However, in a polytrauma patient, when the patient must be kept in the supine position, supine and lateral decubitus views can be performed.
Chest X-ray has been the mainstay diagnostic modality for pneumothorax. Typically, it demonstrates the visceral pleural edge, which appears as a thin, sharp white line. The peripheral space is more radiolucent compared to the adjacent lung (Image 1). A deep sulcus sign can be observed on a supine X-ray (Image 2).
More x-ray images can be found in iEM’s Flickr account – https://www.flickr.com/search/?user_id=158045134%40N08&view_all=1&text=pneumothorax
A chest x-ray provides information about the size of the pneumothorax and assists in determining the next steps in management.
In a patient with suspected pneumothorax, a chest x-ray should be performed [5]. However, if clinical assessment suggests features of tension pneumothorax (e.g., hypotension, tracheal deviation, distended neck vein), a needle thoracocentesis must be performed first, as a chest x-ray may delay this life-saving intervention.
CT scan
The presence of bullous lung disease can lead to a misdiagnosis of pneumothorax on a chest x-ray. In patients with chronic lung disease who develop bullae, a chest x-ray may show features similar to pneumothorax. Therefore, if uncertainty exists, a CT scan of the thorax is strongly recommended.
More CT images can be found in iEM’s Flickr account – https://www.flickr.com/search/?user_id=158045134%40N08&view_all=1&text=pneumothorax
CT scan is considered the “gold standard” for detecting small pneumothoraces and is the most accurate method to determine the size of a pneumothorax [6]. However, practical drawbacks, such as limited availability, make it unsuitable as the first imaging modality for diagnosing pneumothorax.
Lung Ultrasound
In the emergency department, a lung ultrasound can be performed at the bedside immediately after a physical examination to evaluate undifferentiated respiratory failure. It is part of the point-of-care ultrasound protocol in emergency settings.
In a lung ultrasound, the normal lung interface with pleura shows lung sliding with Z-lines, which appear as vertical comet tails descending from the pleural surface. In pneumothorax, this sliding and the comet tail artifacts from the pleura are absent. Visualizing the intersection between the sliding lung sign and the absence of sliding is referred to as the lung point, which is nearly 100% specific for pneumothorax [7].
Additional ultrasound findings:
- Absence of B-lines
- Cessation of lung pulse (lung oscillation in tandem with cardiac contraction)
On M-mode, the following signs are observed:
- Seashore sign: Indicates normal lung sliding.
- Barcode/stratosphere sign: Indicates pneumothorax.
More US images can be found in iEM’s Flickr account – https://www.flickr.com/search/?user_id=158045134%40N08&view_all=1&text=pneumothorax
Laboratory Tests
ABG is indicated when oxygen saturation is below 90% on room air. It is performed to assess the patient’s oxygenation level, as some patients with pneumothorax may present with hypoxemia [8].
Risk Stratification
Pneumothorax is classified into primary spontaneous pneumothorax (PSP) and secondary pneumothorax (SSP). PSP occurs in healthy patients; hence, it is termed “spontaneous,” while SSP is associated with underlying lung diseases such as chronic obstructive pulmonary disease and pulmonary tuberculosis. PSP patients are typically taller than healthy controls [9-11]. Within the first four years, the risk of recurrence of PSP is as high as 54%, with isolated risk factors including smoking, height, and age above 60 years [10, 12,13]. Age, pulmonary fibrosis, and emphysema are risk factors for the recurrence of SSP [11,13].
Since patients with pre-existing lung diseases tolerate a pneumothorax less well, distinguishing between PSP and SSP at the time of diagnosis is critical for determining the next steps in care. Many patients, particularly those with PSP, do not seek medical attention until several days after their symptoms first appear. Meanwhile, the majority of patients with SSP present with more severe clinical symptoms.
Management
General Principle
Airway
The majority of patients with pneumothorax experience breathing issues rather than airway compromise. However, it is essential to assess the airway and breathing simultaneously.
Breathing
Provide supplemental oxygen with a high-flow mask. Oxygen treatment accelerates the resolution of pneumothorax by lowering the partial pressure of nitrogen in the alveoli relative to the pleural cavity. This creates a diffusion gradient for nitrogen, which hastens recovery.
The diagram from the British Thoracic Society guideline summarizes the management of pneumothorax [14].
When To Admit This Patient
Patients requiring chest tube thoracostomy insertion must be admitted for monitoring and removal prior to discharge home. Those utilizing a pigtail catheter experience fewer complications, shorter hospital stays, and faster time-to-device removal. While many patients will require hospitalization, some can be discharged after a period of observation, aspiration, or with a Heimlich valve in pigtail catheters [14,15].
Revisiting Your Patient
The patient presented to the Emergency Department in a stable condition, showing no signs of respiratory distress, and was initially seen in the non-critical zone. After a chest X-ray confirmed the diagnosis of pneumothorax, the patient was transferred to the resuscitation zone for management and close monitoring.
A systematic assessment and management plan for patients with pneumothorax should prioritize the identification and stabilization of hemodynamically unstable patients.
Airway
There was no airway compromise in this patient, so no intervention was needed. The examination also revealed no tracheal deviation, which decreases the suspicion of a tension pneumothorax.
Breathing
Although the patient did not appear to be in respiratory distress, high-flow oxygen was administered through a non-rebreather mask to expedite the resorption of the pneumothorax.
Circulation
The patient was not in a tension pneumothorax state, as he remained hemodynamically stable. Therefore, he did not require immediate needle decompression or chest drain insertion.
The next step was to decide on the treatment approach. Following the algorithm set out by the British Thoracic Society, needle aspiration is recommended for this patient with a spontaneous pneumothorax, especially since he was experiencing breathlessness.
Needle aspiration is preferred in cases of spontaneous primary pneumothorax, as it is associated with a higher rate of successful discharges and fewer complications. However, if needle aspiration fails, chest drain insertion and admission will be necessary. The failure rate of needle aspiration in cases of secondary pneumothorax is high, which is why chest drains are typically favored in those instances.
Authors
Mohd Fazrul Mokhtar
Dr Mohd Fazrul Mokhtar is a Consultant Emergency Physician at Faculty of Medicine Universiti Teknologi MARA, Malaysia. He obtained his postgraduate training in emergency medicine at Universiti Kebangsaan Malaysia. He has special interest in sepsis, medical simulation; and emergency critical care. He is currently the Coordinator of the Clinical Simulation Centre. His research niche includes CPR educational technologies, cardiac arrest and sepsis. He is the council member of Malaysian Sepsis Association and Malaysian Resuscitation Association.
Raja Amir Fikri Raja Sulong Ahmad
I am currently a second year postgraduate trainee in Emergency Medicine in Malaysia. My interests are point of care ultrasound and critical care.
Listen to the chapter
References
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- McKnight CL, Burns B. Pneumothorax. Nih.gov. Published 2019. https://www.ncbi.nlm.nih.gov/books/NBK441885
- Aljehani YM, Almajid FM, Niaz RC, Elghoneimy YF. Management of Primary Spontaneous Pneumothorax: A Single-center Experience. Saudi J Med Med Sci. 2018 May-Aug;6(2):100-103. doi: 10.4103/sjmms.sjmms_163_16. Epub 2018 Apr 16. PMID: 30787829; PMCID: PMC6196700.
- Newman MJ. A mistaken case of tension pneumothorax. BMJ Case Rep. 2014 May 16;2014:bcr2013203435. doi: 10.1136/bcr-2013-203435. PMID: 24835806; PMCID: PMC4024963.
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- Volpicelli G. (2011). Sonographic diagnosis of pneumothorax. Intensive care medicine, 37(2), 224–232. https://doi.org/10.1007/s00134-010-2079-y
- Inoue S, Egi M, Kotani J, Morita K. Accuracy of blood-glucose measurements using glucose meters and arterial blood gas analyzers in critically ill adult patients: systematic review. Crit Care. 2013 Mar 18;17(2):R48. doi: 10.1186/cc12567. PMID: 23506841; PMCID: PMC3672636.
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- Sadikot RT, Greene T, Meadows K, et al. Recurrence of primary pneumothorax. Thorax 1997;52:805–9.
- Videm V, Pillgram-Larsen J, Ellingsen O, et al. Spontaneous pneumothorax in chronic obstructive pulmonary disease: complications, treatment and recurrences. Eur J Respir Dis 1987;71:365–71.
- West JB. Distribution of mechanical stress in the lung, a possible factor in the localisation of pulmonary disease. Lancet 1971;1:839–41.
- Lippert HL, Lund O, Blegrad S, et al. Independent risk factors for cumulative recurrence rate after first spontaneous pneumothorax. Eur Respir J 1991;4:324–31.
- MacDuff A, Arnold A, Harvey J; BTS Pleural Disease Guideline Group. Management of spontaneous pneumothorax: British Thoracic Society Pleural Disease Guideline 2010. Thorax. 2010 Aug;65 Suppl 2:ii18-31. doi: 10.1136/thx.2010.136986. PMID: 20696690.
- Thelle A, Gjerdevik M, SueChu M, Hagen OM, Bakke P. Randomised comparison of needle aspiration and chest tube drainage in spontaneous pneumothorax. European Respiratory Journal. 2017;49(4). doi:https://doi.org/10.1183/13993003.01296-2016
FOAm and Further Reading
Reviewed and Edited By
Erin Simon, DO
Dr. Erin L. Simon is a Professor of Emergency Medicine at Northeast Ohio Medical University. She is Vice Chair of Research for Cleveland Clinic Emergency Services and Medical Director for the Cleveland Clinic Bath emergency department. Dr. Simon serves as a reviewer for multiple academic emergency medicine journals.
Arif Alper Cevik, MD, FEMAT, FIFEM
Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.
