Tag Archives: hemothorax

Retained Hemothorax And Empyema

Patients with chest trauma sustain hemothorax on occasion. The trauma professional usually picks this diagnosis up in the initial evaluation and makes a decision whether or not to drain it. The parameters for this decision are not very clear, even today. But what happens when there is residual hemothorax? Should we be more aggressive in getting it out?

All this boils down to an understanding of the natural history of retained hemothorax. This kind of information can help us decide whether to be more aggressive in our efforts to remove it. The results of a multicenter study looking at this issue was published recently. They focused on patients who had a chest tube placed for management of either hemo- or pneumothorax within 24 hours of admission. Patients who had suspected retained hemothorax after tube removal received a CT scan within 14 days. The usual outcomes were studied (length of stay, complications) as well as development of empyema (purulence, acidic pleural fluid, positive Gram stain or culture).

Some interesting results:

  • 328 patients were enrolled across 20 centers. Not a lot, but one of the bigger studies to date.
  • Empyema was diagnosed in 27% of patients
  • Risk factors identified included rib fractures, ISS > 25, and performance of additional interventions for drainage
  • Patients who developed empyema stayed in the ICU and the hospital longer

Bottom line: Retained hemothorax turns into a very serious problem in a quarter of trauma patients who have a chest tube inserted. The presence of residual blood after the chest tube is removed should prompt us to figure out if it’s solid clot or liquid blood (remember the old decubitus view chest xray? They still work!). If it’s liquid, consider drainage via thoracentesis or a smaller catheter. If it’s clot, it may require more invasive techniques to drain it (VATS). If you decide to send the patient home, have them watch out for fevers, chest pain, dyspnea and other symptoms and signs of a developing complication, and make sure they report it to you promptly.

Related post:

Reference: Development of posttraumatic empyema in patients with retained hemothorax: Results of a prospective, observational AAST study. J Trauma 73(3):752-757, 2012.

Extended FAST Exam in Trauma Patients

By now, every emergency medicine physician and surgeon knows what FAST is. This valuable technique allows us to quickly (get it?) determine whether a patient has blood in the abdomen or around the heart which might require operative management. Extended FAST (E-FAST) is an extension of the original technique that allows us to detect the presence of pneumothorax or hemothorax more quickly and accurately than with the conventional chest x-ray.

Both hemothorax and pneumothorax can be missed by x-ray. It takes at least 200cc of free fluid in the chest to show on the chest x-ray, assuming an ideal body habitus. As little as 20cc can be detected using the E-FAST. Studies have also shown that 30-50% of pneumothoraces are missed by x-ray. This diagnostic inaccuracy is due to the fact that hemothoraces settle out posteriorly and pneumothoraces anteriorly. Since the vast majority of chest x-rays in major trauma patients are taken with the patient supine to protect their spine, the bulk of the blood or air have layered out and cannot be seen well. A chest x-ray is still needed, however, to determine injury to the mediastinum and lung parenchyma.

E-FAST exam can be performed by using the standard curvilinear probe. It is usually placed longitudinally on the anterior chest to detect pneumothorax, using the space between two ribs as the “window” to the pleura. The depth setting should be adjusted so that only about 4cm is visible on the display. The junction of the visceral and parietal pleura should be visualized at the backside of the ribs. With a very steady hand, the junction between the two sets of pleura should be scrutinized closely.

If the two sets of pleura slide freely over each other, pneumothorax is unlikely. If not, it may be present. Pneumothorax is not a uniform phenomenon, except when it is of large size. It may be necessary to move the probe to a few other rib spaces to ensure that a smaller pneumothorax is not present.

FALSE POSITIVE ALERT! If the patient is not ventilating well, or if they have a right mainstem intubation, the affected lung(s) may not show the sliding sign, leading the examiner to think they have a problem when they may not.

To detect a hemothorax, the probe is directed upward somewhat when doing the right and left upper abdominal views. A dark triangle located above the diaphragm indicates fluid in the chest (blood). The dark crescent on the left in the image below is a large hemothorax.

E-FAST hemothorax

The bottom line: Extended FAST can be helpful in detecting a significant hemothorax or pneumothorax and can expedite the definitive management of those conditions. If you are already familiar with FAST, a little extra ultrasound training may be very helpful.

Chest Tubes and Autotransfusion

Chest trauma is common in trauma patients. Chest tubes are required with some regularity for the management of hemothorax and/or pneumothorax. Occasionally, the amount of blood in the chest is substantial, and when the tube goes in we wish that we were able to transfuse that blood.

Well, you can! Most collection systems have optional autotransfusion canisters that connect to the chest tube inline with the collection system. The canisters are used to collect shed blood and can then be hung like a bag of blood from the blood bank.

A few key points about using autotransfusion canisters:

  • I recommend you consider it for any chest tube being inserted for trauma. They will almost always have some blood in their chest.
  • If you want to limit use further due to the expense, just add it for trauma activation patients.
  • Always add it to the chest tube collection system before the chest tube goes in. Most of the blood will be lost if the chest tube is hooked to the collection system first.
  • No need to anticoagulate the blood. Most systems can be used to reinfuse shed blood up to 6 hours after collection without heparin or other products.
  • Be sure to use an inline blood filter. There will be some debris and clumps that must be removed.
  • Don’t use the blood if it is likely to be contaminated. This most often occurs with penetrating trauma, where a stab or gunshot could injure stomach or colon and violate the diaphragm.
  • Follow the manufacturer’s instructions for your brand of collection system.

Here’s a picture of an autotransfuser that attaches to a Pleur-Evac brand system.

Autotransfuser set