From the Guidelines
Immediate treatment of hypotension in ruptured abdominal aortic aneurysm (rAAA) requires rapid volume resuscitation with a permissive hypotension strategy, aiming for a systolic blood pressure of 80-100 mmHg to maintain organ perfusion while minimizing ongoing bleeding. This approach is crucial in preventing the lethal triad of hypothermia, acidosis, and coagulopathy, which can significantly increase morbidity and mortality in these patients 1.
Key Considerations
- Begin with two large-bore IV access lines (16-18 gauge) and administer crystalloid fluids (normal saline or lactated Ringer's) in 500mL boluses, titrated to blood pressure response.
- Blood products should be initiated early, with a 1:1:1 ratio of packed red blood cells, fresh frozen plasma, and platelets for massive transfusion, as supported by recent guidelines 1.
- Avoid excessive fluid resuscitation as this can worsen bleeding by disrupting forming clots and diluting coagulation factors.
- Vasopressors like norepinephrine (starting at 0.05-0.1 mcg/kg/min) may be needed as a bridge to definitive surgical management, which is the ultimate treatment.
Definitive Management
The ultimate goal in managing hypotension in rAAA is to facilitate rapid transfer to definitive surgical intervention, which is the only way to stop the hemorrhage and save the patient's life. Immediate surgical consultation is essential, and if rAAA is suspected clinically, one should proceed directly to the operating room while resuscitation continues, as emphasized in the 2022 ACC/AHA guideline for the diagnosis and management of aortic disease 1.
Evidence Support
Recent studies, including the 2022 ACC/AHA guideline, support the use of a permissive hypotension strategy and prompt surgical intervention in the management of rAAA, highlighting the importance of a multidisciplinary approach to improve outcomes in these critically ill patients 1.
From the FDA Drug Label
Restoration of Blood Pressure in Acute Hypotensive States Blood volume depletion should always be corrected as fully as possible before any vasopressor is administered. When, as an emergency measure, intraaortic pressures must be maintained to prevent cerebral or coronary artery ischemia, LEVOPHED can be administered before and concurrently with blood volume replacement Average Dosage: Add the content of the vial (4 mg/4 mL) of LEVOPHED to 1,000 mL of a 5 percent dextrose containing solution. Each mL of this dilution contains 4 mcg of the base of LEVOPHED Give this solution by intravenous infusion. After observing the response to an initial dose of 2 mL to 3 mL (from 8 mcg to 12 mcg of base) per minute, adjust the rate of flow to establish and maintain a low normal blood pressure (usually 80 mm Hg to 100 mm Hg systolic) sufficient to maintain the circulation to vital organs
To treat hypotension in ruptured abdominal aortic aneurysm, blood volume depletion should be corrected as fully as possible before administering any vasopressor.
- Norepinephrine (LEVOPHED) can be administered before and concurrently with blood volume replacement to maintain intraaortic pressures and prevent cerebral or coronary artery ischemia.
- The average dosage is 8 mcg to 12 mcg of base per minute, which can be adjusted to establish and maintain a low normal blood pressure (usually 80 mm Hg to 100 mm Hg systolic).
- The infusion should be titrated according to the response of the patient, with the goal of maintaining adequate blood pressure and tissue perfusion 2.
From the Research
Treatment of Hypotension in Ruptured Abdominal Aortic Aneurysm
- The management of haemorrhagic shock is crucial for the person's outcome and aims to restore organ perfusion and systolic blood pressure above 100 mmHg through immediate and aggressive fluid replacement 3.
- An alternative to the normotensive resuscitation strategy is the controlled (permissive) hypotension resuscitation strategy, with a target systolic blood pressure of 50 mmHg to 100 mmHg 3.
- Resuscitative endovascular balloon occlusion of the aorta (REBOA) contributes to hemodynamic stability, and a two-stage approach can be used to manage ruptured abdominal aortic aneurysm 4.
- Endovascular methods such as balloon occlusion and endovascular repair (EVAR) in patients with suitable anatomy are recommended to reduce mortality 5.
Predictors of Survival
- Findings on admission that significantly correlated with both intraoperative and total intrahospital mortality were: systolic blood pressure < 95 mmHg, low diuresis, unconsciousness, cardiac arrest, leukocytes > 14 x 10(9)/l, hematocrit < 0.29%, hemoglobin < 100 g/l, urea > 11 mmol/l, and creatinine > 180 micro mol/l 6.
- Intraoperative determinants of increased mortality were: aortic cross-clamping time > 47 min, duration of surgery > 200 min, intraoperative blood loss > 3,500 ml, diuresis < 400 ml, arterial systolic pressure < 97.5 mmHg, and the need for aortobifemoral bypass 6.