Subcutaneous emphysema

Subcutaneous emphysema
Other namesSurgical emphysema, tissue emphysema, sub Q air
An abdominal CT scan of a patient with subcutaneous emphysema (arrows)
SpecialtyEmergency medicine

Subcutaneous emphysema (SCE, SE) occurs when gas or air accumulates and seeps under the skin, where normally no gas should be present. Subcutaneous refers to the subcutaneous tissue, and emphysema refers to trapped air pockets. Since the air generally comes from the chest cavity, subcutaneous emphysema usually occurs around the upper torso, such as on the chest, neck, face, axillae and arms, where it is able to travel with little resistance along the loose connective tissue within the superficial fascia.[1] Subcutaneous emphysema has a characteristic crackling-feel to the touch, a sensation that has been described as similar to touching warm Rice Krispies.[2] This sensation of air under the skin is known as subcutaneous crepitation, a form of crepitus.

Numerous etiologies of subcutaneous emphysema have been described. Pneumomediastinum was first recognized as a medical entity by Laennec, who reported it as a consequence of trauma in 1819. Later, in 1939, at Johns Hopkins Hospital, Dr. Louis Hamman described it in postpartum woman; indeed, subcutaneous emphysema is sometimes known as Hamman's syndrome. However, in some medical circles, it can instead be more commonly known as Macklin's Syndrome after L. Macklin, in 1939, and C.C. and M.T. Macklin, in 1944, who cumulatively went on to describe the pathophysiology in more detail.[3]

Subcutaneous emphysema can result from puncture of parts of the respiratory or gastrointestinal systems. Particularly in the chest and neck, air may become trapped as a result of penetrating trauma (e.g., gunshot wounds or stab wounds) or blunt trauma. Infection (e.g., gas gangrene) can cause gas to be trapped in the subcutaneous tissues. Subcutaneous emphysema can be caused by medical procedures and medical conditions that cause the pressure in the alveoli of the lung to be higher than that in the tissues outside of them.[4] Its most common causes are pneumothorax or a chest tube that has become occluded by a blood clot or fibrinous material. It can also occur spontaneously due to rupture of the alveoli, with dramatic presentation.[5] When the condition is caused by surgery it is called surgical emphysema.[6] The term spontaneous subcutaneous emphysema is used when the cause is not clear.[5] Subcutaneous emphysema is not typically dangerous in and of itself, however it can be a symptom of very dangerous underlying conditions, such as pneumothorax.[7] Although the underlying conditions require treatment, subcutaneous emphysema usually does not; small amounts of air are reabsorbed by the body. However, subcutaneous emphysema can be uncomfortable and may interfere with breathing, and is often treated by removing air from the tissues, for example by using large bore needles, skin incisions or subcutaneous catheterization.

  1. ^ Papiris SA, Roussos C (2004). "Pleural disease in the intensive care unit". In Bouros D (ed.). Pleural Disease (Lung Biology in Health and Disease). Florida: Bendy Jean Baptiste. pp. 771–777. ISBN 978-0-8247-4027-6. Retrieved 2008-05-16.
  2. ^ Lefor, Alan T. (2002). Critical Care on Call. New York: Lange Medical Books/McGraw-Hill, Medical Publishing Division. pp. 238–240. ISBN 978-0-07-137345-6. Retrieved 2008-05-09.
  3. ^ Macklin, M. T; C. C Macklin (1944). "Malignant interstitial emphysema of the lungs and mediastinum as an important occult complication in many respiratory diseases and other conditions: an interpretation of the clinical literature in the light of laboratory experiment". Medicine. 23 (4): 281–358. doi:10.1097/00005792-194412000-00001. S2CID 56803581.
  4. ^ Maunder RJ, Pierson DJ, Hudson LD (July 1984). "Subcutaneous and mediastinal emphysema. Pathophysiology, diagnosis, and management". Arch. Intern. Med. 144 (7): 1447–53. doi:10.1001/archinte.144.7.1447. PMID 6375617.
  5. ^ a b Parker GS, Mosborg DA, Foley RW, Stiernberg CM (September 1990). "Spontaneous cervical and mediastinal emphysema". Laryngoscope. 100 (9): 938–940. doi:10.1288/00005537-199009000-00005. PMID 2395401. S2CID 21114664.
  6. ^ Oxford Concise Medical Dictionary (6th ed.). Oxford, UK: Oxford University Press. 2003. ISBN 978-0-19-860753-3.
  7. ^ Brooks DR (1998). Current Review of Minimally Invasive Surgery. Philadelphia: Current Medicine. p. 36. ISBN 978-0-387-98338-7.