SAEM Clinical Images Series: Dusky Feet
A 94-year-old female with a past medical history of hypertension, coronary artery disease, chronic venous stasis, and permanent pacemaker placement initially presented to triage complaining of left hip pain in the setting of a fall shortly prior to arrival. Upon further evaluation, she endorsed developing sudden bilateral lower extremity weakness causing her to fall to the floor. She then experienced excruciating pain from her umbilicus down to her groin, hips, and legs (left greater than right), describing it as “being in labor.” She denied any recent fevers, chills, chest pain, shortness of breath, leg swelling, back pain, urinary symptoms, or bloody stools,
Vitals: BP 109/58; Temp 36°C; Pulse 89; RR 18; SpO2 96%
Constitutional: Uncomfortable
Abdominal: No tenderness to palpation or distension No visible or palpable hernias.
Neuro: Awake, alert, oriented x 3. 0/5 strength in bilateral lower extremities. 5/5 strength in bilateral upper extremities.
Extremities: Bilateral radial pulses intact and palpable. Bilateral feet with chronic venous stasis. They are dusky in appearance. They are cool to the touch with poor capillary refill. Palpable left dorsalis pedis pulse, absent right dorsalis pedis pulse. Within 10 minutes of initial exam, bilateral lower extremity pulses are no longer palpable or dopplerable.
Hemoglobin/Hematocrit: 13.2 g/dL, 41.5%
BUN/Creatinine: 27 mg/dL, 0.99 mg/dL
Troponin: 20 (reference range <40)
Lactic acid: 3.61
This is a case of a Type A aortic dissection. An aortic dissection is a vascular emergency that occurs when the inner wall of the aorta is weakened to the point where it tears and causes blood to accumulate between the inner and middle layers. The type of aortic dissection depends on the location of the tear; Type A dissections involve the ascending aorta whereas Type B dissections involve the descending portion of the aorta. Patients most commonly present with severe chest and back pain, however, a combination of these symptoms with abdominal and neurological complaints are sometimes seen. The exam can include hypertension, wide pulse pressure, diastolic murmur, muffled heart sounds, loss of pulses, and even neurological deficits. While a history and physical exam can strongly suggest the diagnosis, a Computed Tomography Angiography (CTA) of the chest, abdomen, and pelvis can confirm it.
Aortic dissection malperfusion syndromes imply end-organ ischemia to the vascular distributions being compromised. There can be renal, mesenteric, neurological, and even extremity malperfusion. If malperfusion is already present during the diagnosis of the aortic dissection, this can increase the patient’s mortality. In the case of this specific patient, there was lower extremity malperfusion and thus ischemia secondary to the extension of her dissection from the diaphragm to the bilateral external iliac arteries with likely occlusion of the vessels by the dissection flap. This explained her lower extremity discoloration and pulse deficits.
Take-Home Points
- The diagnosis of an aortic dissection is made via a CTA of the chest, abdomen, and pelvis.
- Aortic dissections with malperfusion syndromes have increased mortality.
- Lower extremity malperfusion includes loss of extremity pulses with pain, paresthesias and/or paralysis.
- Levy D, Goyal A, Grigorova Y, Farci F, Le JK. Aortic Dissection. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. 2023 Jan.
- Crawford TC, Beaulieu RJ, Ehlert BA, Ratchford EV, Black JH 3rd. Malperfusion syndromes in aortic dissections. Vasc Med. 2016 Jun;21(3):264-73. doi: 10.1177/1358863X15625371. Epub 2016 Feb 8. PMID: 26858183; PMCID: PMC4876056.
- Harris C, Croce B, Cao C. Type A aortic dissection. Ann Cardiothorac Surg. 2016 May; 5(3):256. doi: 10.21037/acs.2016.05.04. PMID: 27386417; PMCID: PMC4893534.
- Gargiulo M, Bianchini Massoni C, Gallitto E, Freyrie A, Trimarchi S, Faggioli G, Stella A. Lower limb malperfusion in type B aortic dissection: a systematic review. Ann Cardiothorac Surg. 2014 Jul; 3(4):351-67. doi: 10.3978/j.issn.2225-319X.2014.07.05. PMID: 25133098; PMCID: PMC4128931.
- Hasan I, Brown JA, Serna-Gallegos D, Zhu J, Garvey J, Yousef S, Sultan I. Lower-extremity malperfusion syndrome in patients undergoing proximal aortic surgery for acute type A aortic dissection. JTCVS Open. 2023 May 6;15:1-13. doi: 10.1016/j.xjon.2023.04.015. PMID: 37808049; PMCID: PMC10556830.