Hemothorax
By Donald R. Elton, MD, FCCP
Lexington Pulmonary and Critical Care
Definition
A hemothorax is a collection of blood in the pleural space. It is classified according to the amount of blood. 350 ml or less is considered minimal, 350-1500 ml is moderate, and greater than 1500 ml is considered massive. In many cases, blood in the pleural cavity will be diluted by other pleural fluid. In these cases, the pleural fluid hematocrit can be used to diagnose a hemothorax using a hematocrit of greater than half the serum hematocrit as diagnostic of hemothorax.
Presentation
The presentation of hemothorax is related primarily to the acuity in that a chronic or slowly accumulating hemothorax may be asymptomatic while an acute hemothorax may present with shock, anemia, and respiratory compromise relating to compression of the lung and mediastinum by pressurized blood resembling the presentation of a tension pneumothorax.
Etiology
Trauma is an important cause of hemothorax. Hemothorax may result from either blunt or penetrating trauma of the chest but can also result from trauma to the abdomen such as from a ruptured spleen or liver. A ruptured ectopic pregnancy, bleeding from recent abdominal or pelvic surgery, or a ruptured abdominal aneurysm can also cause a hemothorax. Blood most commonly comes from systemic chest-wall vessels but can get to the pleural space from the pulmonary and/or bronchial vasculature. Other diagnostic considerations for hemothorax include malignancy (lung or pleural), or a pulmonary embolus or infarct. An unusual iatrogenic cause of hemothorax is from insertion of a central IV line through a vascular structure and into the pleural cavity.
Treatment
Chest tube drainage is the primary therapy for a hemothorax and 85% of cases will resolve spontaneously with only this treatment. If blood loss continues at a rate higher than 100-200 ml / hour then a thoracotomy should be considered remembering that a hemothorax could originate in the abdomen.
References
Lewis FR, Krupski WC, Trunkey DD: Management of the Injured Patient In Way LW (Ed.), Current Surgical Diagnosis & Treatment, Lange Medical Publications, 1983. Pp 194-5.
Conners AF, Altose MD: Pleural Anatomy, Pleural Fluid Dynamics, and the Diagnosis of Pleural Disease In Baum GL, Wolinsky E (Ed.), Textbook of Pulmonary Diseases, 4th edition, Little, Brown and Company, 1989. p 1569.
Ganji H, Vidrine A: Ectopic Pregnancy presenting as hemothorax, American Journal of Surgery 1970 December; 120(6) 807-9.
Pratt JH, Shamblin WR: Spontaneous hemothorax as a direct complication of hemoperitoneum, Annals of Surgery 1968 June; 167(6) 867-72.