Ultrasound-Guided Resuscitation in Open Aortic Surgery

The intervention group will receive a 4-view transthoracic echocardiogram including Parasternal long axis, parasternal short axis, apical 4-chamber, and supplemental subcostal short-axis/4-chamber views as needed. A standard 4-view thoracic lung ultrasound study will assess the left and right anterior chest wall, anterior axillary regions, as well as the costophrenic angle and posterolateral regions. At 5 discrete time intervals post-operatively, POCUS assessments will be used to adjust fluid resuscitation to fluid liberal (2cc/kg/hr) or fluid restrictive (0.8cc/kg/hr). Routine vital signs, biochemistry, and urine output as well as bedside physical exam will be assessed as usual. IV boluses of crystalloid will be permitted to treat hypotension with SBP \<90mmHg with clinical signs of hypovolemia, but oliguria will not be used as a marker to titrate fluid infusion rates. Blood transfusion may be used for post-operative bleeding or anemia as clinically indicated.

"The control group for usual care will undergo resuscitation guided by modalities used currently, which can include both static and dynamic measures. These will include review of vital signs, biochemistry, and urine output as well as bedside physical exam. In this arm, patients will not undergo POCUS during their admission. IV fluid infusion rates as well as targets for IV boluses will be left to the discretion of the attending physician and can include hypotension, hypovolemia, as well as oliguria. Blood transfusion may be used for post-operative bleeding or anemia as clinically indicated."