The typical presentation of a rectus sheath hematoma is that of abdominal pain and its associated symptoms like nausea and vomiting. The pain is often sudden in onset, sharp and does not radiate. In extremely rare cases, the hematoma may be large and present with hypovolemia, tachycardia, and tachypnea. Physical exam usually reveals a palpable localized mass which is non-pulsatile. The Fothergill sign (mass in the abdominal wall that does not cross the midline and does not change with flexion of the rectus muscles is suggestive of a rectus sheath hematoma) is useful to determine if the abdominal mass is within the abdominal wall or intra-abdominal cavity. It is not a highly sensitive sign and is often inconclusive in obese individuals.

The clinician should obtain a thorough medical history to determine the presence of any risk factors like surgery, coughing, constipation, asthma, bronchitis, anticoagulation therapy and use of oral anticoagulants and steroids.

Ultrasound is the first test of choice to confirm the diagnosis of a rectus sheath hematoma after basic blood work, and coagulation profile are obtained. The hematoma appears as hypoechoic space in the posterior rectus sheath. Further information like the size and exact location of the hematoma can be obtained from the ultrasound study. If the ultrasound study is inconclusive, a CT scan is the next test. It can show more details about the location, size, and extension of the hematoma. When intravenous contrast is administered with the CT scan, active bleeding can be detected by the presence of the contrast in the form of blush in the hematoma if the bleeding is active.

Unless a contrast is visualized in the hematoma, the differential diagnosis of a fluid collection in the rectus sheath should not be ignored. If the diagnosis of hematoma is still in doubt after imaging, needle aspiration can be performed to differentiate a hematoma from an abscess. However, with needle aspiration, there is a risk of puncture the bladder, bowel, or a hernia.[11]

Evaluation of the hematoma should be part of the comprehensive evaluation of the patient condition. General assessment with addressing the related factors and conditions causing the hematoma or as a complication of the hematoma is necessary for a proper evaluation[12]. Simultaneous treatment of the underlying condition and the possible or pending complications is mandatory for successful management. 

Treatment of Rectus hematomas depends on the severity of symptoms, size, the stability of the hematoma, and the underlying pathology. The goal of the treatment is to relieve or minimize symptoms, prevent complications, and address the underlying condition. Proper patient's condition assessment, volume replacement, and correction of any coagulation abnormalities are important initial measures that should be performed before considering more aggressive steps.

If the hematoma is enlarging and or causing significant blood loss, intervention should be taken to stop the bleeding. Interventional radiology localizing and embolizing the bleeding vessel is the appropriate first modality of treatment to use. In most of the cases, this is successful and sufficient to stop the bleeding, especially with the confined space and the pressure created that counteracts the flow of bleeding.

In a few cases of ongoing bleeding that is not amenable to radiologic intervention or if the service is not available, surgical control of the bleeding and evacuation of the hematoma are necessary. Controlling the bleeding is achieved by ligating the bleeding vessel (epigastric vessel) surgically.

In most cases, bleeding stops after enough pressure build-up inside the rectus sheath. The size of the developed hematoma varies according to the size and pressure of the bleeding vessel, expandability of the rectus space, and the presence and severity of coagulation abnormalities. Once the bleeding stops and the hematoma size stabilizes, treatment is usually directed on the symptoms relief. There is no urgency in evacuating the hematoma. In fact, maintaining the pressure inside the hematoma at the initial phase is important to prevent rebleeding. Large hematomas can be drained percutaneously after stabilization and recovery from the acute phase. Small hematomas can be left to be reabsorbed spontaneously to avoid unnecessary intervention.  

Patients with rectus sheath hematoma can be treated as outpatients as long as the hemodynamic status is stable and there is no change in the hematocrit. Patients on anticoagulation therapy should be admitted to ensure that the hematoma is not expanding.[7][13]

Conditions presenting with a mass:

• Abdominal wall tumors (benign an malignant).
• Abdominal wall abscess.
• Abdominal wall hernia[14].

Conditions presenting pain or acute abdomen:

• Peptic ulcer disease.
• Bowel perforation.
• Tubo-ovarian abscess.
• Appendicitis.
• Cholecystitis.
• Diverticulitis[15].
• Urinary tract infection.
• Pancreatitis.

A comprehensive history, physical exam and work up with a low index of suspicion will usually identify the pathology, confirm the diagnosis and assist in the management planning.

Most cases of rectus hematomas are self-limited, non-life-threatening, and can be identified and treated successfully with minimal interventions. Even though, fatalities have been reported. Most of the fatality cases have come to light during an autopsy. Rectus sheath hematoma mortality is higher in elderly individuals who are on oral anticoagulants. Another population group that is at higher risk for mortality are pregnant women. Anecdotal old reports reveal a mortality rate of 15% in the mother and nearly 50% in the fetus. However, it is important to know that these data were collected before the wide use of ultrasound and CT scan. Today, these imaging modalities can rapidly diagnose the condition.

The main consequence of undiagnosed or untreated rectus hematomas is pain. In addition to pain, severe bleeding is serious and can be life-threatening. Therefore sever bleeding should be promptly identified and aggressively treated. Another potential complication is abscess formation. As in any blood collection that is not drained, there is always a chance of superseding infection and development of an abscess. Draining of abscess becomes mandatory when it develops.

Follow up and reassessment including physical activities adjustment to prevent recurrent and further tissue damage. Patients should be advised to avoid indulging in heavy exercises. The decision to restart oral anticoagulation requires clinical judgment and balance between the indication of anticoagulation treatment and possible rebleeding in the rectus sheath.

Rectus hematoma is a surgical condition. Once a patient has been diagnosed with a rectus sheath hematoma, surgical consultation should be made. Interventional radiology and hematology specialties may be needed depending on the severity and or the underlying condition.

• Rectus sheath hematoma is an uncommon disorder.
• It can be confused with other abdominal wall pathologies like tumors or hernias.
• Ultrasound or CT scan can assist in confirming the diagnosis.
• Many patients are on oral anticoagulation therapy. This should be held.
• The condition is usually treated conservatively with pain control and supportive treatment.
• In a few cases, arterial embolization or surgical intervention are required to stop the bleeding.

Abdominal wall hematoma can occur from a variety of causes. The patient often presents with abdominal pain which can be mistaken for a number of abdominal pathologies; hence an interprofessional approach to management is necessary. Nurses should be aware of and familiar with abdominal hematomas as they can occur from repeated LWMH or insulin injections; they can consult with the pharmacy team to ensure proper dosing and that there are no drug interactions that contribute to the condition. The diagnosis can be difficult to confirm clinically. Imaging studies are usually necessary. Most abdominal hematomas resolve spontaneously over 4 to 6 weeks. Nowadays, mortality rates from abdominal wall hematomas are negligible because of the availability of imaging studies. Patients who recover usually have no residual sequelae. These outcomes are made possible as described above by interprofessional teamwork and collaboration/communication, contributing to positive patient outcomes. [Level 5]