Rectus sheath hematoma: Clinical sciences

Rectus sheath hematoma refers to an accumulation of blood within the sheath of the rectus abdominis muscle. It typically occurs as a result of an injury to the epigastric artery or one of its branches, either due to abdominal trauma, or forceful contractions of the abdominal wall. There are three types of rectus sheath hematoma. Type I is located within the rectus abdominis. Type II is when the blood builds up between the muscle and the fascia, while Type III extends into the peritoneum.

Alright, the first thing you should do if you suspect a rectus sheath hematoma is an ABCDE assessment to determine if your patient is unstable or stable. If the patient is unstable, you need to stabilize their airway, breathing, and circulation. This means that you may need to intubate the patient, establish IV access, and administer fluids before continuing with your assessment. If the patient doesn’t respond to these measures, consult the surgical team right away.

On the flip side, if the patient is stable, your next step is to obtain a focused history and physical examination, and order labs such as CBC followed by serial hemoglobin and hematocrit levels every 4 to 6 hours, and coagulation studies, including PT, INR, and PTT. Now, patients with a rectus sheath hematoma usually report acute abdominal pain, which is often sharp, persistent, and non-radiating.

History might also reveal some important risk factors like anticoagulation or antiplatelet therapy; recent abdominal surgery; pregnancy; biological female sex ; or chronic conditions such as renal disease, cirrhosis, arteriosclerosis, and hypertension. Additionally, patients with a history of asthma and COPD may also be at an increased risk due to repeated and forceful contractions of the rectus abdominis muscle during coughing spells.

On the other hand, the physical exam usually reveals abdominal wall ecchymosis as well as tender, palpable, and non-pulsating abdominal mass in the area of the hematoma, which doesn’t cross the midline due to the linea alba confining it.

During the exam, you should assess your patient for two clinical signs called Carnett sign and Fothergill sign. Carnett sign is used to determine if the pain originates from the abdominal wall muscles, or intra-abdominally, from the abdominal viscera. Carnett sign is a two-step test. First, have the patient relax and palpate the abdomen to localize the pain. Then, have the patient tense their abdominal muscles and palpate the same point again. If the pain worsens, it is from the abdominal wall, and Carnett sign is positive. However, if the pain remains the same, then you should think of intra-abdominal causes. When it comes to the Fothergill sign, it is used to determine if the mass is extra-abdominal, or intra-abdominal. Fothergill sign is positive if the abdominal mass remains fixed when the patient contracts the abdominal wall muscles. On the flip side, if the mass “disappears”, it’s probably located within the abdomen and you should think of alternative diagnoses.

Finally, labs might show a decrease in hemoglobin, and elevated coagulation studies like PT, INR, or PTT.

Okay, if the history, physical exam, and labs suggest rectus sheath hematoma, order a CT of the abdomen and pelvis. If you are worried about an active bleed, order the CT scan with IV contrast.