(P01) Monster in the Belly- ruptured Abdominal Aortic Aneurysm Diagnosed Through Bedside Point-of-care Ultrasound

Chief Complaint : Pt presents from NH due to evaluation of abdominal pain and lethargy.

History of Present Illness : 86-year-old F with PMH of CVA, HTN, CAD, COPD presented to the ED from NH due to sudden, non-radiating, sharp left-sided abdominal pain that started yesterday afternoon. SHe was resting when the pain started and she has never had this pain before. Endorses one episode of NBNB emesis. Denies alcohol, cigarettes, recreational drugs. Denies, fevers, chills, dysuria, hematuria, numbness, tingling, loss of sensation. Pt is A&Ox3, verbalizing pain to her trunk. Pt received pain control. A curvilinear probe was placed on the patient's abdomen and flank to assess for nephrolithiasis, biliary pathology, and vascular competence when a pulsating enlarged Abdominal Aortic Aneurysm (AAA) concerning for rupture was identified. Vascular surgery was urgently consulted. Patient was hemodynamically stable and therefore CTA was performed. It was remarkable for 7.1 cm AAA with associated rupture. Patient was taken for emergent EVAR for ruptured AAA with exclusion of right kidney.

Pertinent Physical Exam: Vital signs were unremarkable with BP of 113/78, afebrile, heart rate of 82, respiratory rate of 17 and saturating at 97% on room air. Patient was lying on a stretcher with no acute distress, appearing fatigued on exam, and pointing to her abdomen when asked to localize pain. Tenderness to palpation of the LUQ and LLQ. Otherwise unremarkable physical exam.

Pertinent Laboratory Data: EKG: sinus tachycardia with RBBB in leads V1/V2 and non-specific ST-T wave changes.
Labs: WBCs (21.6) and Lactate (2.6). Labs otherwise unremarkable.
Radiographs: POCUS remarkable for AAA with false and triple lumen, clot present within the false lumen. CTA remarkable for ruptured infra-renal 7.1 cm AAA. No free fluid in RUQ

Case Discussion: Abdominal pain is a common complaint in the emergency department. Differential includes (but is not limited to) small bowel obstruction, gallstones, pancreatitis, peptic ulcer disease, myocardial infarction, nephrolithiasis, etc. Initial workup of abdominal pain usually includes H&P, EKG, and labs including BMP, CBC, Lipase, and Urinalysis. Patients with a ruptured abdominal aortic aneurysm (AAA) usually present with abdominal, back or flank pain, pulsatile abdominal mass, and hypotension (1). Most of them rupture into the retroperitoneal cavity. Several predisposing factors such as older age, male gender, hypertension, history of smoking, and first degree relatives with history of AAA have all been identified as increasing the likelihood of aneurysm formation. (2).

CTA is the preferred diagnostic modality of choice for ruptured AAA, however point-of-care ultrasound is more readily available in most EDs. ED ultrasound screening for ruptured AAA has been found to reduce the time to diagnosis and improve patient outcomes (3). ED point-of-care ultrasound has a sensitivity of 99% and specificity of 98% for the detection of AAA, however it is much less useful in identifying rupture. Almost 88% of AAAs rupture into the retroperitoneal space, where ultrasound is limited (2). Catalona et al. described 8 sonographic findings of AAA in 29 patients(4). The four findings in our patient are marked in Figure 1.

When AAA rupture is confirmed, early consultation with a vascular surgeon can help facilitate disposition to the operating room. Two large bore peripheral IV catheters, continuous hemodynamic monitoring, and labs to assess baseline hemoglobin, renal function, and coagulation status should be obtained. Along with the patient being cross-matched for infusion of packed red blood cells, as well as fresh frozen plasma and platelets in anticipation of the potential need for massive transfusion (5).

References and Acknowledgements (Optional): 1. Chaikof EL, Brewster DC, Dalman RL, Makaroun MS, Illig KA, Sicard GA, Timaran CH, Upchurch GR Jr, Veith FJ. Society for Vascular Surgery. The care of patients with an abdominal aortic aneurysm: the Society for Vascular Surgery practice guidelines. J Vasc Surg. 2009;50(4 Suppl):S2-49. https://doi.org/10.1016/j.jvs.2009.07.002 (PMID: 19786250).

2. Lech C, Swaminathan A. Abdominal aortic emergencies. Emerg Med Clin North Am. 2017;35(4):847–67.

3. Plummer D, Clinton J, Matthew B. Emergency department ultrasound improves time to diagnosis and survival in ruptured abdominal aortic aneurysm [Abstract]. Acad Emerg Med. 1998;5(5):417.

4. Catalano O, Siani A. Ruptured abdominal aortic aneurysm. Categorization of sonographic findings and report of 3 new signs. J Ultrasound Med. 2005;24(8):1077–1083.

5. Jeanmonod D, Yelamanchili VS, Jeanmonod R. Abdominal Aortic Aneurysm Rupture. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459176/