A rectus sheath hematoma is caused by accumulation of blood in the sheath of the rectus abdominis muscle. Symptoms include abdominal pain in the presence or absence of a mass. The hematoma is either caused by muscular tear or rupture of the epigastric artery. In a similar case, a 68-year-old man presented with abdominal pain. The patient developed influenza-like symptoms a week earlier with fever, persistent cough and chills.
Doctors prescribed the patient azithromycin for 5 days. However, after being started on the medication he complained of shearing abdominal pain. The pain was initially non-radiating and restricted to the right mid abdomen. In addition, exacerbated on coughing. However, over the next 2 days the pain increased in intensity and involved the bilateral lower quadrants, also. He sought medical attention after the pain in his abdomen exacerbated.
Abdominal ultrasound confirmed the presence of a rectus sheath hematoma
His medical history revealed atrial fibrillation, coronary artery disease and hypertension for which the doctors had prescribed him aspirin and apixaban twice a day. Examination showed that the patient was hemodynamically stable with no changes in the skin. Whereas on palpation, multiple swellings were palpable over the abdominal wall. Abdominal ultrasound confirmed the presence of a rectus sheath hematoma measuring 9.0 mm × 45.6 mm in size. Doctors lowered the dose to half for a week after which he was put back on the earlier dose of the medication. The pain and swelling subsided gradually over the next 4 weeks.
Apixaban is an oral anticoagulant that inhibits factor Xa and is indicated for prevention of stroke in cases of non-valvular atrial fibrillation. The drug is metabolised by cytochrome p450(CYP)3A4. It is recommended to reduce 50% of the dose of apixaban in patients prescribed a strong cytochrome p450(CYP)3A4 inhibitor. Despite azithromycin being a mild inhibitor, current literature does not recommend adjusting the dose. In this case it posed as a risk of development of rectus sheath hematoma.
Rectus sheath hematoma should be ruled out in patient who are on anticoagulants, presenting with abdominal pain, swellings and severe cough.
Patients can be diagnosed with abdominopelvic CT or ultrasound. Management is decided based on the patient’s clinical status. Most patients are seen responding to supportive medical care including volume resuscitation and symptomatic management. Surgical intervention is recommended for refractory cases.
The oral anticoagulants can be restarted after evidence of resolving and stable hematoma and haemoglobin. The case study further states that resuming oral anticoagulants after 4 days of treatment are found to be safe in most patients with limited thrombotic complications. It is important that the possibility of drug interaction is assessed when prescribing anticoagulants treatment to patient, as bleeding episodes can prove to be fatal.
References
Rectus sheath hematoma due to drug–drug interaction https://casereports.bmj.com/content/14/5/e242751
