Case Presentation by Dr. Sarah Michael
CC: I can’t breathe!
A 21-year-old female is transported to the emergency department after an apparent domestic dispute. On arrival, it is apparent that she has multiple stab wounds to her chest and abdomen. She is alert and oriented but in acute distress. Her blood pressure is 98/64, pulse 112, respirations 32 and oxygen saturation 94% on nonrebreather mask. There is no jugular venous distension. You can appreciate a small degree of tracheal deviation. An eFAST is performed which includes the following findings.
1. The most appropriate next step in the management of this patient is:
A: Needle decompression of the right hemithorax
B: Left-sided chest tube
C: CT of the chest, abdomen and pelvis
D: Emergent transport to OR
2. The patient’s clinical status remains unchanged. A repeat U/S shows the following:
Now the most appropriate next step is:
A: Chest tube placement
C: Finger thoracostomy
D: Chest x-ray
3. Which of the following is true regarding the patient’s belongings?
A: They should be placed in a plastic bag and remain with her.
B: They should be placed in paper bags and offered to the police.
C: If ED staff handles them they lose their forensic value.
D: Blood-soaked items should be placed in biohazard waste.
Answers & Discussion:
1. The answer is A, needle decompression.
The patient in the vignette is in shock and her physical exam is concerning for a tension pneumothorax with respiratory distress and hypotension. Notably, JVD may be absent in the hypotensive patient. In order to correctly answer the question, you need to be able to interpret the eFAST findings.
An eFAST (extended FAST) exam includes the normal FAST structures as well as the lung at the 3-4 intercostal space on the anterior chest wall. This is the most superior aspect of the chest in a supine patient and the location where you would expect air to accumulate. You’re given 3 images to interpret.
The first image is of Morrison’s pouch, the most sensitive FAST view for intraperitoneal free fluid. This patient has a renal fat pad that could be mistaken for free fluid. You should be able to appreciate that the structure is lenticular with internal echoes and bounded by the hyperechoic line of the renal capsule. This is known as the double line sign and is a frequent cause of a false positive FAST examination. Therefore, it is not a reason to rush the patient to the OR. If it’s helpful, think about it as a renal corollary of the pericardial fat pad that can sometimes mimic pericardial effusion.
The second image shows you a normal M-mode ultrasound of the right lung. You can see the “seashore sign” with an abrupt transition between the chest wall and lung parenchyma at the pleura. It would be imprudent to place a chest tube on the unaffected side.
The third image shows you the lung point of the left lung, indicating the presence of a pneumothorax. This is the place on the chest wall where the lung transitions from pneumothorax to being against the chest wall. In M-mode, you’d be able to see both the “seashore” and “barcode” signs vary with respiration. In a setting concerning for tension, needle decompression is the way to go. Intubating the patient before decompression risks further destabilization. Fixing a tension pneumothorax may also prevent the need for intubation.
2: The correct answer is A, chest tube placement.
In the trauma patient with persistent respiratory distress and decreased breath sounds after needle decompression, you should consider chest tube placement for presumptive hemothorax per ATLS guidelines. Chest tube placement is certainly indicated given the ultrasound image, which demonstrates a massive hemothorax. There is near complete consolidation of the lung as it floats in a sea of fluid. The M-mode graphic shows the movement of the lung edge with respiratory variation.
The patient may need intubation for respiratory failure (and definitely for her trip to the OR). But intubation before tension is resolved would likely worsen the tension and could be disastrous. Similarly, tension pneumo- or hemo-thorax is a clinical diagnosis and treatment should not be delayed by imaging.
Thoracotomy in the OR is indicated for patients who have a chest tube output of 1500 cc or greater of blood during the first hour. Given the appearance on ultrasound, more than 1500 cc would be expected. However, the tension should be relieved at once and not delayed by transportation to the OR.
Finger thoracotomy should be considered and is an option if you are uncertain of the diagnosis of hemothorax. In this case the diagnosis is not in doubt and chest tube is required. A chest tube is also indicated once a decompressive needle thoracostomy is performed. Furthermore, a hemothorax this large will likely re-accumulate very quickly.
3. The correct answer is B.
The patient is a victim of a violent crime and her clothing, through which she was stabbed, likely contains valuable forensic evidence. Caring for the patient obviously takes priority over the preservation of such evidence, but steps can be taken to maintain evidence integrity so long as they do not delay care. When removing a patient’s clothing, try to avoid cutting through stab or bullet holes and always wear gloves. In some cases, the frequent changing of gloves can help to keep from cross-contaminating evidence. Even if evidence is collected or handled suboptimally in the provision of care for the patient, it is not worthless and should still be made available to investigators.
After being removed from the patient, clothing should be placed in separate paper bags and given to law enforcement. The paper bags will allow the blood to dry in a way that does not promote the formation of mildew, which can destroy the evidence. Blood soaked items should be placed in separate plastic bags followed by separate paper bags. Law enforcement should be informed that the items are soaked so they can be dried appropriately.
If law enforcement declines the evidence, it should be returned to the patient.