Endgames Picture Quiz

Post-traumatic swelling

BMJ 2012; 345 doi: http://dx.doi.org/10.1136/bmj.e6363 (Published 27 September 2012) Cite this as: BMJ 2012;345:e6363
  1. Andrew O’Keeffe, Fulbright science and technology fellow123,
  2. Jane Terris, consultant in accident and emergency medicine2
  1. 1Orthopaedics and Trauma, Oxford University, Oxford OX4 3DS, UK
  2. 2Emergency Department, John Radcliffe Hospital, Oxford
  3. 3University of California, Los Angeles, CA, USA
  1. Correspondence to: A O’Keeffe andrewbokeeffe{at}yahoo.com

A 49 year old woman presented to the emergency department with facial swelling (fig 1). She had fallen four days previously, striking her back on a large piece of concrete. After picking herself up she proceeded with her normal activities. The morning after the fall she awoke with swelling of the ankles. The swelling gradually spread throughout her body and four days later it began to compromise her vision. On admission to the emergency department she was generally fit and well, despite the swelling, although she was slightly short of breath on exertion.

Figure1

Fig 1 Patient’s appearance at presentation

On examination she had gross swelling of the chest wall and abdomen extending to the ankles and wrists in the periphery. Breath sounds could be auscultated with a small amount of continuous pressure to the chest wall with the stethoscope. There was a hyper-resonant percussion note and reduced breath sounds on the left side of the thorax, with mild tenderness to percussion on the left posterior thorax over the eighth, ninth, and tenth ribs. Her vision was reduced owing to restricted eye opening, but when her eyelids were opened manually her pupils were equal and reactive to light and accommodation bilaterally. Visual acuity and eye movements were normal in both eyes. All other systems examinations were normal and oxygen saturations on room air were 96%. She underwent computed tomography of the thorax (fig 2)

Figure2

Fig 2 Computed tomography of the thorax

Questions

  • 1 What is the differential diagnosis for widespread soft tissue swelling?

  • 2 What does the computed tomogram show about the type of swelling and its causes?

  • 3 What is the underlying pathophysiology of this condition and what are the presenting symptoms and life threatening complications?

  • 4 What treatments should be implemented?

Answers

1 What is the differential diagnosis for widespread soft tissue swelling?

Short answer

The causes of generalised swelling can be broadly divided into two categories: swelling caused by accumulation of fluids or an accumulation of gas. The first category includes heart failure, renal failure, nephrotic syndrome, hypoalbuminaemia, thyroid disease, and drugs. Anaphylaxis can result in diffuse angio-oedema over the course of several minutes. In the second category, massive subcutaneous emphysema can cause generalised swelling.

Long answer

Anasarca (from the Greek, meaning “throughout the flesh”) or generalised oedema most often results from disequilibrium of Starling forces, which maintain intravascular and extravascular compartment ratios. According to these principles fluid distribution depends on venous tone, capillary permeability, oncotic pressure, and lymphatic drainage.1 Most conditions characterised by abnormal swelling are caused by sodium chloride retention, and, although not commonly a result of oral sodium chloride consumption, widespread oedema can be iatrogenically induced by overzealous infusion of intravenous saline.

Generalised swelling is commonly caused by oedema secondary to severe heart failure,2 and may be associated with reduced voltages on electrocardiography.3 Several drugs can induce oedema through the increased retention of sodium and water, including oestrogens, mineralocorticoids, and non-steroidal anti-inflammatory drugs. The differential diagnoses also include initiation of insulin treatment in diabetes; drugs that cause relaxation of precapillary arterioles, such as nifedipine; and infectious agents, such as hookworm. Pre-eclampsia can cause a diffuse swelling by raising arterial blood pressure, which acts to upset the Starling equilibrium. Water is forced out of the intravascular compartment and into the extravascular compartment as a consequence. Diuretics are currently used in many oedematous conditions to stimulate excretion of sodium and water through direct actions on the kidneys. Some classes of diuretic also increase venous capacitance and reduce preload, both of which can have an almost immediate benefit on symptoms in heart failure. The 2010 National Institute for Health and Clinical Excellence guidelines for heart failure recommend the use of diuretics for relief of congestive symptoms and fluid retention in all types of heart failure.4

It is important to establish the underlying cause of generalised swelling because treatment should be tailored to the underlying condition. In malnutrition, for example, low intravascular osmotic pressures can arise as a result of hypoalbuminaemia. Restoration of nutritional intake is the definitive management, although the administration of colloid may provide immediate relief of symptoms. The use of intravenous albumin is currently thought not to help correct hypoalbuminaemia and may even adversely affect outcomes in neurotrauma.5

Subcutaneous emphysema results from trapping of air within the subcutaneous tissue planes and it typically elicits a crackling sensation when palpated. It is often an iatrogenic phenomenon seen around drain sites, particularly in the chest, head, and neck. Radiologically it can be identified as a radiolucent area within the subcutaneous tissues. On chest radiographs radiolucency in the mediastinum or surrounding the cardiac shadow may indicate pneumomediastinum or pneumopericardium, respectively. Although subcutaneous emphysema is usually a benign phenomenon resulting from surgical interventions or a pneumothorax, it can also indicate a serious and acutely evolving condition, such as a perforated oesophagus or viscus. Rapid onset is a key indicator that a serious disease may be responsible for the subcutaneous gas. When this phenomenon presents as a rapidly occurring feature or one that causes systemic compromise it should never be ignored and must be managed as an emergency so that a source can be found as soon as possible.

2 What does the computed tomogram show about the type of swelling and its causes?

Short answer

The computed tomogram shows a left sided pneumohaemothorax. There is pneumomediastinum with extensive gas throughout the subcutaneous tissues. One left sided posterior rib fracture can also be seen.

Long answer

A chest radiograph that was performed initially showed diffuse subcutaneous air and air within the mediastinum. However, it failed to identify a pneumothorax or the source of the air that was escaping into the soft tissue.

Computed tomography of the thorax was subsequently performed to identify the origin of the subcutaneous gas. Analysis of the entire slice set showed three posterior rib fractures (eighth, ninth, and tenth ribs) on the left hand side, with extensive air tracking in the mediastinum, subcutaneous tissues, and retroperitoneum. There was evidence of left sided lung contusions and a haemopneumothorax on the left without signs of tension. The extensive accumulation of air in the subcutaneous tissues helps delineate the pectoralis major muscles (fig 3). Computed tomography is therefore useful in rapidly determining the underlying condition, and these results helped us form an appropriate management plan to tackle the cause of the subcutaneous emphysema.

Figure3

Fig 3 Computed tomography of the thorax showing (A) subcutaneous air, (B) pectoralis major, (C) air in the pleural cavity, (D) air in the mediastinum, (E) blood pooling in the pleural cavity, and (F) posterior rib fracture

3 What is the underlying pathophysiology of this condition and what are the presenting symptoms and life threatening complications?

Short answer

Subcutaneous emphysema is usually caused by pneumothorax, a blocked chest drain, or trauma to the chest, but it can result from any puncture of the gastrointestinal or respiratory systems. In the intensive care setting it can be caused by barotrauma to the lungs during positive pressure ventilation, when a peripheral alveolar rupture results in dissection of the air into the parenchyma and vascular sheaths of the lung.6 It is known as surgical emphysema when caused by a surgical procedure. Subcutaneous emphysema can also occur as a result of necrotising fasciitis. It typically presents with painless distension of the skin and crepitations on palpation. Life threatening complications include swelling and occlusion of the airways, which result in respiratory compromise.

Long answer

The mechanism of subcutaneous and mediastinal emphysema is linked to increased intra-alveolar pressure leading to the rupture of alveoli in the lung. This is followed by a slow leak of air into the parenchyma of the lung and subsequent tracking into the mediastinum.7 In our case, subcutaneous emphysema could be caused by direct alveolar rupture into the pleural space, possibly as a result of a rib fracture causing parenchymal puncture. The finding of a small haemothorax associated with the pneumothorax on the left supports this hypothesis.

Haemopneumothorax is most often caused by blunt and penetrating trauma to the chest, but it can occur spontaneously and is usually associated with a ruptured bulla in the pleural parenchyma.8 Spontaneous haemopneumothorax accounts for 1-12% of cases of spontaneous pneumothorax and is about 30 times more common in men than in women.9 Transfusion and thoracotomy may be needed in cases of persistent bleeding to control the blood loss. In two case reports of spontaneous haemopneumothorax that required surgical intervention, vascular adhesions associated with a lung bulla were identified as the cause of the bleeding.10 Retrospective case series of spontaneous haemopneumothorax have advocated rapid emergent intervention, which is thought to prevent the occurrence of restrictive lung deficits in the recovery period and improve long term quality of life.11

Case reports and literature reviews cite numerous causes of subcutaneous emphysema including vomiting,12 laparoscopic procedures,13 tonsillectomy,14 pulmonary barotrauma,15 midfacial fracture,16 and even penetrating injury to the tonsillar fossa.17 Severe airway compromise is a recognised complication of massive amounts of subcutaneous air and is thought to result from swelling in the submucosal layers of the oropharyngeal airways.18 Few reports describe subcutaneous emphysema to such a great extent as was seen in our patient.

Subcutaneous air typically presents in the postoperative period and is associated with some disruption of the skin or mucosa that allows air to enter into the subcutaneous tissues. It presents with diffuse swelling of the skin, which is usually painless and has a characteristic “bubble wrap” or “rice krispie” feel on palpation. In spontaneous pneumothorax the presenting features may be breathlessness or, as in our patient, visual difficulties resulting from periorbital swelling. Spontaneous pneumomediastinum has been associated with Hammam’s sign, a crepitus that is in synchrony with the heart sounds on auscultation of the chest.

Massive subcutaneous emphysema is a rare condition that can have serious consequences, including upper airway obstruction.19 In our patient, the relative absence of systemic compromise is surprising considering the extent of the subcutaneous emphysema. Perhaps the ability of the air to track freely throughout the subcutaneous tissues of the body prevented a build-up of air in tissues such as the oropharynx, which may have resulted in more severe sequelae including respiratory distress.

4 What treatments should be implemented?

Short answer

Oxygen, insertion of a chest drain to resolve the haemopneumothorax, followed by radiography to assess the positioning of the chest drain within the pleural cavity, cardiac monitoring, and monitoring of oxygen saturations. Consider prophylactic antibiotics and analgesics for pain.

Long answer

Subcutaneous emphysema is normally a benign condition and commonly results from surgical procedures involving the thorax.20 A patient who presents with generalised subcutaneous emphysema should have its cause investigated. Treatment depends on the origin of the subcutaneous gas. Small amounts of air are reabsorbed over several hours or days and rarely require further measures. Progressive subcutaneous emphysema should always be investigated and after surgery, may indicate leakage from the bronchial tree. In cases of subcutaneous emphysema secondary to a pneumothorax, insertion of a chest drain can help to reinflate the lung and prevent worsening of the subcutaneous accumulation of air. Traumatic haemopneumothorax is an indication for insertion of a chest drain according to British Thoracic Society guidelines.21

In our case, fluid resuscitation was initiated in the emergency department and some resolution of the swelling occurred over the course of two hours. In accordance with British Thoracic Society guidelines a chest drain was inserted into the left hemithorax and the symptoms resolved over the next two days. The patient was kept on the trauma unit where blood pressure, oxygen saturations, respiratory rate, and pulse rate were measured hourly. She self discharged two days after admission, after removal of the chest drain. A chest radiograph performed before discharge showed complete resolution of the haemopneumothorax.

The management of massive surgical emphysema depends on the causes and extent of systemic compromise. If a chest drain is already in place, its functioning should be checked. If there is no vascular or respiratory compromise, an expectant approach has been suggested,22 involving regular electrocardiography and monitoring of respiratory rate, pulse, blood pressure, and oxygen saturations. A sensible precaution is to advise patients to avoid sneezing and coughing, which can induce the forced entry of air into the subcutaneous tissues. Some authors advocate the use of prophylactic broad spectrum antibiotics in case the subcutaneous dissection has introduced bacteria into the subcutaneous tissues.22 23

One article described four cases of massive subcutaneous emphysema with cardiorespiratory compromise and their acute management in intensive care with infraclavicular “blow holes.”18 This involved an emergency procedure under aseptic conditions with 3 cm incisions down to the pectoralis fascia. The intervention resulted in immediate resolution of the symptoms and physiological compromise in two cases, obviating the need for reintubation and emergency bronchoscopy. In all four patients no further invasive treatment was needed and the massive subcutaneous emphysema rapidly resolved. This report used bronchoscopy in one of the compromised patients to identify epiglottal swelling and narrowing of the laryngeal interoitus as contributing to acute respiratory compromise from subcutaneous emphysema.

When clinical examination or vital signs suggest that subcutaneous emphysema is causing cardiorespiratory compromise, pre-emptive intubation is a sensible measure to take. Rapid sequence induction is now commonly practised in emergency rooms for intubation of patients whose airway status is deteriorating rapidly.24 This technique involves the near simultaneous administration of a potent induction agent and neuromuscular blockers to sedate, paralyse, and intubate patients who have difficulty maintaining their airway. In skilled hands rapid sequence induction has a success rate of 98% and a low rate of complications.25 In the acute situation assessment of difficulty for intubation is best performed by a physician directly inspecting the oropharyngeal airway with a tongue blade or laryngoscope. This is because 65% of patients with trauma have a hard cervical collar, which complicates assessment of the airway using standard anaesthetic techniques or placement of a definitive airway.26

As might be expected, the management of oedematous causes of generalised swelling differs greatly from that of subcutaneous emphysema. Lymphoedema is normally more localised but can be difficult to treat. Good resolution can normally be obtained with conservative measures, such as compression stockings and elevation of the affected body part to increase lymphatic return. Surgical options have variable efficacy and are usually adopted only as palliative measures. Rarer causes of oedema, such as dermatomyositis,27 may need treatment with drugs such as steroids or immunomodulatory agents.

Patient outcome

Our patient was managed with a chest drain and underwater valve system and her symptoms resolved within 48 hours. She self discharged against medical advice on day 2 but six months later has made a full and uncomplicated recovery with no recurrences.

Notes

Cite this as: BMJ 2012;345:e6363

Footnotes

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

  • Patient consent obtained.

References