P040: PARADOXICAL HEMODYNAMICS DURING A MYCOTIC AORTIC ABDOMINAL ANEURYSM REPAIR.
Juan Mora, MD, Amie Hoefnagel, MD; University of Florida - Jacksonville
Introduction: Open abdominal aortic procedures are performed for occlusive or aneurysmal aortic disease. Aneurysms commonly develop from degenerative processes of the aortic wall. Occasionally, infection causes abdominal aortic aneurysm (AAA), which is related to poor outcomes both before and after repair. These infectious or “mycotic” aneurysms account for 2.6% of all the aortic aneurysms, and early diagnosis and treatment is vital to avoid fatal outcomes. The patient usually presents with abdominal or back pain, fever, weight loss, and elevations of the WBC and ESR. Final diagnosis can be confirmed with CT angiography.
Intraoperatively, various hemodynamic changes have been widely described in the literature, the severity of those variations will depend mainly on the aortic clamp location. Immediately after clamping, an increase of the afterload leading to hypertension is usually seen. After the clamp is released, due to the accumulation of vasodilating metabolites and vascular dilation distal to the clamp, severe hypotension is expected.
Anesthesiologists are vital in the adequate management of these patients. Preparation of pertinent vasoactive medications, adequate IV access, and monitoring are necessary for a successful procedure.
Case description: A 53-year-old male with past medical history of diabetes and hypertension presented to the ED with bilateral sharp lower back pain rated as 9/10, radiated to the left testicle. CT scan revealed a bilobed 3.2 cm aneurysm in the infrarenal abdominal aorta with periaortic stranding and adenopathy, compatible with a mycotic aneurysm. The patient was started on antibiotics and scheduled for open AAA repair. A preoperative thoracic epidural was placed (infusion not started), general anesthesia was induced, and arterial line and right IJ central line were placed. Before clamping mannitol was given to the patient and vasodilatory medications were prepared. Immediately after clamping patient showed no significant increase in the blood pressure. But progressively during the case and with the clamp on, the patient became hypotensive with requirements of fluid resuscitation and infusion of 3 different vasoactive agents (phenylephrine, vasopressin, and epinephrine) to maintain adequate mean arterial pressures. TEE was used revealing adequate cardiac contractility with hyperdynamic state. When surgeon proceeded to release the clamp, the patient did not show a marked hypotension, all the opposite, patient was able to be weaned off the vasopressors minutes after the release. After abdominal closure, the patient was extubated and transported to the recovery room.
Discussion: Anesthetic management of non-infectious AAA repairs has been widely described. A mycotic aortic aneurysm is a rare entity that can give paradoxical hemodynamic changes, this might be related to release of inflammation factors contained in the area around the aneurysm. We describe the case of a patient undergoing AAA repair that did not follow the predicted hemodynamic behavior during the periods of clamping and unclamping of the aorta during the repair.