History

Fact Explanation
Sudden onset severe, pleuritic, continuous chest pain. Air accumulates in the pleural space (owing to internal or external communication with the atmosphere). This causes the pleural membranes to stretch; which generates pain as the parietal pleura is pain sensitive. [1],[2],[3]
Dyspnea Initially, the pleural space expands with air and the negative intrapleural pressure responsible for keeping the lung expanded is reversed [2]; as a result of which the lung collapses. Subsequently, the expansion of the lung is labored (Patient becomes dyspneic).
Restlessness and agitation Persistent chest pain, dyspnea and psychological factors such as fear produce anxiety in the patient.[2]
Alteration of consciousness / drowsiness This is a late symptom.The collapsed lung leads to a ventilation-perfusion (V/Q) mismatch, resulting in a reduction in partial pressure of oxygen (PaO2) ie. hypoxia and an increase in partial pressure of carbon dioxide (PaCO2) ie. hypercarbia. Inadequate oxygen concentration in the cerebral circulation leads to impaired functioning at the cellular level; thus resulting in alteration of consciousness [4].
Cardiac arrest and loss of consciousness In a tension pneumothorax, a one-way valve mechanism gives rise to a progressive increase in intrapleural pressure; owing to which the mediastinal structures including the trachea and superior vena cava (SVC) are shifted to the contralateral side.This deviation is sufficient to result in a kink of the SVC, resulting in a reduction of the venous return to the heart and subsequently to the systemic circulation (including coronary and cerebral circulation). Both the myocardium and the cardiac center in the brain stem are thus suppressed, giving rise to cardiopulmonary arrest.[4]
History of Trauma 1.Penetrating injuries can create an open and a continuous communication between the atmosphere and the pleural space (open pneumothorax) or a tension pneumothorax.[1][2] 2.Blunt trauma may cause fractures of the ribs and rupture of the bronchi that can create a communication between the alveolar space and the pleural space giving rise to a pneumothorax.[1][2]
History of invasive procedures (pleural aspirations, central venous catheterizations) [1][2] ie. iatrogenic trauma.
Diagnosed patient with connective tissue disorders (Eg: Marfan syndrome) Mostly suspected in spontaneous pneumothoraces. Congenital Bullae are present in some patients which can expand, rupture and create a communication with the pleural space [3]
History of lung diseases (COPD, cystic fibrosis, tuberculosis) Forceful respiratory efforts and high-pressure artificial ventilation can expand blebs in the lungs which may rupture and create a communication with the pleural space. [1][2]
References
  1. McDUFF,Andrew.ARNOLD Anthony.HARVEY,Jhon.Management of spontaneous pneumothorax:JHONSTON,S.L. ed. British Thoracic Scociety Pleural disease guidline 2010:inThorax AN INTERNATIONAL JOURNAL OF RESPIRATORY MEDICINE.BMJ Publishing group 2010.vol6.pg18-31.doi10.1136/thx2010.136978.
  2. CURRIE,Graeme P.ALLURI, Ratna. CHRISTIE,Gordon L . LEGGE, Joe S.Pneumothorax: an update.Postgrad Med Journal.BMJ Group. Jul 2007; 83(981): 461–465.doi: 10.1136/pgmj.2007.056978
  3. LUH,Shi-ping .Diagnosis and treatment of primary spontaneous pneumothorax.Journal of Zhejiang University Science B. Oct 2010; 11(10): 735–744. doi:10.1631/jzus.B1000131
  4. ARCINIEGAS,David B.Hypoxic-Ischemic Brain Injury.in:International Brain injury association.2012[Viewed 13 mar 2014].Available form:http://www.internationalbrain.org.

Examination

Fact Explanation
Tracheal deviation to the contralateral side Increased intrapleural pressure on the affected hemithorax causes the trachea to deviate to the contralateral side.[1],[2],[3]
Cyanosis Is a late sign observed in severe hypoxia, where the deoxyhemoglobin levels rise above 5g/dl. The blood is darker in color and the peripheries (lips, tongue etc.) show a bluish discoloration.[4]
Tachypnea Tachypnea is defined as a rapid rate of respiration (above 20 breaths/min). The collapsed lung leads to a ventilation-perfusion mismatch, resulting in a reduction of the partial pressure of oxygen (PaO2) i.e. hypoxia and an increase of the partial pressure of carbon dioxide (PaCO2) i.e. hypercarbia. Both factors act on the respiratory center in the medulla oblongata to increase the rate of respiration, mainly as a compensatory mechanism.[5]
Reduced chest movements on the affected side The lung is collapsed; therefore, chest expansion is reduced. [1],[2],[3]
Hyper-resonant percussion note on the affected side. The hyper-resonance is due to the collapse of the lung. A well expanded lung produces a less resonant percussion note as the lung parenchyma is more dense than a similar volume of air ( note that in a pneumothorax, the volume of the hemi-thorax is occupied by air-filled pleural cavity which overlies a non-expanded lung. ) [1],[2],[3,][4]
Reduced vocal fremitus and vocal resonance The air is a poor conductor of vibration. As the pleural space accumulates air,the conduction of vibrations (generated by the voice) is rendered less efficient.[1],[2],[3],[4]
Reduced breath sounds on the affected side Breath sounds originate in the large airways (bronchi) where air velocity and turbulence generate vibrations in the bronchial walls. These vibrations are then transmitted through the lung tissue and thoracic wall to the surface where they may be heard with the stethoscope. Normal breath sound production is directly related to air flow velocity, and the air flow velocity is primarily determined by pulmonary ventilation which is diminished in a pneumothorax.[1],[2],[3],[4]
Tachycardia Pain and anxiety can cause tachycardia due to the activation of the sympathetic nervous system and the release of catecholamines.[1],[2],[4]
Hypotension This is mainly due to the reduction of the venous return to the heart.[1][2][3][4]
Signs of trauma (contusions, imprints , open wounds, sites of invasive medical procedures) These signs help to identify a probable traumatic cause for the pneumothorax.[3][4]
Signs of precipitating lung disease / connective tissue disorder. These features are only helpful in determining a cause. Ex.01- Barrel shaped chest, Nicotine stains, may indicate underlying COPD Ex.02-The hyper-extendable joints,'Thumb sign' suggests Marfan syndrome. [1][2][3][4]
References
  1. McDUFF,Andrew.ARNOLD Anthony.HARVEY,Jhon.Management of spontaneous pneumothorax:JHONSTON,S.L. ed. British Thoracic Scociety Pleural disease guidline 2010:inThorax AN INTERNATIONAL JOURNAL OF RESPIRATORY MEDICINE.BMJ Publishing group 2010.vol6.pg18-31.doi10.1136/thx2010.136978
  2. CURRIE,Graeme P.ALLURI, Ratna. CHRISTIE,Gordon L . LEGGE, Joe S.Pneumothorax: an update.Postgrad Med Journal.BMJ Group. Jul 2007; 83(981): 461–465.doi: 10.1136/pgmj.2007.056978
  3. Pneumothorax.BMJ best practice 2013[viewed 11 March 2014].Available from: http://bestpractice.bmj.com/best-practicelo
  4. LUH,Shi-ping .Diagnosis and treatment of primary spontaneous pneumothorax.Journal of Zhejiang University Science B. Oct 2010; 11(10): 735–744. doi:10.1631/jzus.B1000131
  5. CRETIKOS, Michelle A. et al.Respiratory rate: the neglected vital sign.The medical journal of Australia. 2008; 188 (11): 657-659.

Differential Diagnoses

Fact Explanation
Asthma, acute exacerbation Patient usually has a past history of asthma. Present episode may be precipitated by chest infection or by an allergen. Typical auscultatory finding is a diffuse polyphonic expiratory wheeze.[1],[2],
COPD, acute exacerbation Patient is usually a chronic smoker and he has a past history of COPD. It is commonly due to an infective exacerbation. On examination, the patient may have a barrel shaped chest and a diffuse polyphonic expiratory wheeze. The other clinical features may vary according to the type of (Type 1/Type 2) respiratory failure. [1],[2],
Pulmonary embolism Patient may present with an acute onset chest pain. Hemoptysis is an important differentiating symptom. Cardiopulmonary arrest is a possibility in the event of a large embolus. In the past medical history, the presence of risk factors for thromboembolism need to be sought. Physical signs such as ankle edema, tender and erythematous limbs, Homans' sign (Pain on passive dorsiflexion of the foot) are suggestive of deep venous thrombosis.[1],[2],[3]
Myocardial ischemia Typically the patient complains of retrosternal, constricting type pain; this may radiate into the neck, shoulder, or down the arms. Accompanying nausea and vomiting are also common. The patient usually has risk factors for Ischemic heart disease.[1],[2],[3]
Pleural effusion Patients will experience pain and dyspnea. Respiratory signs include decreased vocal fremitus, stony dull percussion note, and decreased breath sounds. Most often, there is a precipitating cause (Eg: hypothyroidism). These are useful in differentiation from pneumothorax. [1]
Bronchopleural fistula A bronchopleural fistula is an abnormal communication between the bronchopulmonary tree and bronchial system. Causes include complicated pulmonary resections, persistent spontaneous pneumothoraces, carcinoma of the lung, and tuberculosis being a few. The presentation is similar to a pneumothorax but differentiating signs such as cough, and purulent sputum may be present; a definitive diagnosis may require further investigations. [1]
Esophageal rupture Can occur following instrumentation or paraesophageal surgery, or with forceful vomiting.Has a similar presentation to a pneumothorax but odynophagia is a useful differentiating symptom. The physical exam is usually not helpful, but subcutaneous emphysema in the neck region may support esophageal rupture.[1]
References
  1. Pneumothorax.BMJ best practice 2013[viewed 11 March 2014].Available form:http://bestpractice.bmj.com/best-practice/monograph/504/diagnosis/differential.html
  2. GARDNER,Claire. JONES , Kevin Chest Pain – Pleuritic . MORRIS, Francis ,FLETCHER, Alan .ABC of Emergency Differential Diagnosis .1st ed.London , BMJ Books ..2009
  3. COTTRELL, Daniel. Differential diagnosis of chest pain in adults.Up To Date.2013[viewed 17 March 2014].Available form:http://www.uptodate.com/

Investigations - for Diagnosis

Fact Explanation
Erect, Postero- anterior (PA) Chest X-ray with breath held in inspiration. This is a basic, and freely available investigation and it is diagnostic in a majority of patients. Breath held in Inspiration helps to expand the lungs, which is essential in producing an accurate radiograph. [1]
Lateral Chest X-ray These may provide additional information when a suspected pneumothorax is not confirmed by PA view. Supine and lateral decubitus x-rays have mostly been employed for trauma patients who are unable to stand erect. These views are not routinely requested.[1]
Ultrasound scanning Specific features on ultrasound scanning such as Absence of lung sliding, Comet tail artifacts or ‘B-lines’, 'A-lines' and Lung-point sign are helpful in the diagnosis of a pneumothorax; but to date the main advantage of this technique has been in the management of supine trauma patients.[1][2][3]
CT scanning of the chest This can be regarded as the ‘gold standard’ in the detection of small pneumothoraces, surgical emphysema, bullous lung disease, and for identifying aberrant chest drain placement. However, practical constraints preclude its general use as the initial diagnostic modality.[1][2]
ElectroCardiogram (ECG) Used to differentiate from myocardial infarction and to assess cardiorespiratory reserve.
References
  1. Pneumothorax.BMJ best practice 2013[viewed 11 March 2014].Available form:http://bestpractice.bmj.com/best-practice
  2. McDUFF,Andrew.ARNOLD Anthony.HARVEY,Jhon.Management of spontaneous pneumothorax:JHONSTON,S.L. ed. British Thoracic Scociety Pleural disease guidline 2010:inThorax AN INTERNATIONAL JOURNAL OF RESPIRATORY MEDICINE.BMJ Publishing group 2010.vol6.pg18-31.doi10.1136/thx2010.136978
  3. HUSAIN Lubna F et al. Sonographic diagnosis of pneumothorax. Journal of Emergencies, Trauma, and Shock [online]. 2012 Jan-Mar; 5(1): 76–81 [viewed 18 March 2014] available from: doi: 10.4103/0974-2700.93116

Investigations - Fitness for Management

Fact Explanation
Focused Assessment with Sonography for Trauma (FAST) This is a limited ultrasound examination directed at identifying the presence of free fluid in the perisplenic space, pouch of douglas, pouch of Morison and pericardial space. In the context of traumatic injury, free fluid is usually due to haemorrhage and contributes to the assessment of the circulation. This is helpful in managing other life threatening conditions that may co-exist in the same patient.[1]
References
  1. PARIYADATH,Manoj. SNEAD,Greg.Emergency ultrasound in adults with abdominal and thoracic trauma:In Up To Date.2013[viewde 13 March 2014].Available form:http://www.uptodate.com

Investigations - Followup

Fact Explanation
Post-Intervention chest X-ray To confirm the resolution of the pneumothorax and to confirm that the intercostal tube is in correct placement. [1]
Pulse oximetry The availability and ease of use makes it a very useful method to assess the oxygen saturation, especially in an emergency setting.[1][2]
Arterial blood gas analysis A useful investigation in determining the level of gas exchange, metabolic state of the patient and the electrolyte levels (gives additional information in the diagnosing process and subsequent management (Eg: to assess cardiorespiratory reserve). [1][2]
References
  1. McDUFF,Andrew.ARNOLD Anthony.HARVEY,Jhon.Management of spontaneous pneumothorax:JHONSTON,S.L. ed. British Thoracic Scociety Pleural disease guidline 2010:inThorax AN INTERNATIONAL JOURNAL OF RESPIRATORY MEDICINE.BMJ Publishing group 2010.vol6.pg18-31.doi10.1136/thx2010.136978
  2. Pneumothorax.BMJ best practice 2013[viewed 11 March 2014].Available form:http://bestpractice.bmj.com/best-practice

Management - General Measures

Fact Explanation
Assess Airway, Breathing and Circulation. The patient may present following trauma and may have other complications (Eg: hypovolemia / cardiopulmonary arrest). Requires focused managment (Eg: cardiopulmonary resuscitation).[1][2][3]
Continue the primary survey The principal aim of the primary survey is to identify and treat immediately life-threatening conditions such as; tension pneumothorax, massive hemothorax, open pneumothorax, cardiac tamponade, flail chest.
100% Oxygen The patient is hypoxic and this will further aid in improving oxygen saturation as opposed to atmospheric air alone which has a lower oxygen concentration (the diffusion rate increases as the concentration gradient increases). [1],[2],[3]
Continuous pulse oximetry Monitoring of oxygen saturation. Measurement of end tidal capnography (ET CO2) if patient is intubated.
Pain relief / Sedation Given as premedication once definitive management is underway. Eg: morphine 2.5mg IV or midazolam 1-2mg IV [1]
Secondary Survey This is following initial stabilization of the patient. The secondary survey is a more detailed and complete examination aimed at identifying all injuries and planning further investigation and treatment.
Prophylactic Antibiotics In trauma patients only (Eg: penicillin to cover Clostridium difficile) [1]
Tetanus Toxoid To prevent Clostridium tetani infection in a trauma patient.
References
  1. McDUFF,Andrew.ARNOLD Anthony.HARVEY,Jhon.Management of spontaneous pneumothorax:JHONSTON,S.L. ed. British Thoracic Scociety Pleural disease guidline 2010:inThorax AN INTERNATIONAL JOURNAL OF RESPIRATORY MEDICINE.BMJ Publishing group 2010.vol6.pg18-31.doi10.1136/thx2010.136978
  2. CURRIE,Graeme P.ALLURI, Ratna. CHRISTIE,Gordon L . LEGGE, Joe S.Pneumothorax: an update.Postgrad Med Journal.BMJ Group. Jul 2007; 83(981): 461–465.doi:
  3. Pneumothorax.BMJ best practice 2013[viewed 11 March 2014].Available form:http://bestpractice.bmj.com/best-practice

Management - Specific Treatments

Fact Explanation
Needle thoracostomy / decompression This is an emergency procedure in relieving a tension pneumothorax. A 14 -16 gauged intravenous cannula is inserted into the second rib space in the mid-clavicular line[1]. The needle is withdrawn and the cannula is left open to air. An immediate rush of air out of the chest indicates the presence of a tension pneumothorax. The manoeuvre effectively converts a tension pneumothorax into an open pneumothorax.
Needle aspiration Is carried out for small primary or secondary spontaneous pneumothoraces. This must be performed under aseptic conditions to prevent infections. Usually a 14 - 16 gauged needle is used. Aspiration may be done by a syringe or a 3 way system[1]. It has fewer complications and a relatively shorter hospital stay when compared with an Intercostal (IC) tube. [1],[2],
Chest drain insertion Small-bore Intercostal tube (IC tube less than 14 French gauge) is placed under aseptic conditions using local anesthesia; this is placed in the triangle of safety (The triangle is bordered anteriorly by the lateral edge of pectoralis major, laterally by the lateral edge of latissimus dorsi, inferiorly by the line of the fifth intercostal space and superiorly by the base of the axilla)[1]. The free end is connected to an under-water sealed flutter valve or other recommended drainage system. These drains maintain a negative pressure in the pleural space for the lung to re-expand. [1],[2],[3]
Referral to a thoracic surgeon The referral to a thoracic surgeon is considered in recurrent pneumothoraces, leaking or open pneumothoraces, when removal of pleural bullae is required or when pleurodesis or pleurectomy is required to prevent recurrence. Video assisted thoracoscopic surgery (VATS) has facilitated a less invasive means by which to access the pleural space, especially in more elderly patients with comorbidities.[1],[2]
Medical options Chemical pleurodesis (Eg: sclerosant such as Tetracycline) is used in old, unwilling patients. Needs the expertise of a chest physician with thoracoscopic training.[1],[2]
Observation Considered in small (gap <2cm between chest wall and the lung margin), asymptomatic primary or secondary spontaneous pneumothoraces.[1][2][3]
References
  1. McDUFF,Andrew.ARNOLD Anthony.HARVEY,Jhon.Management of spontaneous pneumothorax:JHONSTON,S.L. ed. British Thoracic Scociety Pleural disease guidline 2010:inThorax AN INTERNATIONAL JOURNAL OF RESPIRATORY MEDICINE.BMJ Publishing group 2010.vol6.pg18-31.doi10.1136/thx2010.136978
  2. CURRIE,Graeme P.ALLURI, Ratna. CHRISTIE,Gordon L . LEGGE, Joe S.Pneumothorax: an update.Postgrad Med Journal.BMJ Group. Jul 2007; 83(981): 461–465.doi: 10.1136/pgmj.2007.056978
  3. Pneumothorax.BMJ best practice 2013[viewed 11 March 2014].Available form:http://bestpractice.bmj.com/best-practice