Question

A 14-day-old male infant is evaluated in the neonatal intensive care unit for new-onset feeding intolerance, abdominal distension, and lethargy. The infant was born prematurely at 28 weeks gestation and has been receiving advanced enteral formula feeds. Current vital signs reveal a temperature of $35.2^\circ\text{C}$ ($95.4^\circ\text{F}$), pulse of $175/\text{min}$, respirations of $65/\text{min}$, and blood pressure of $45/25\text{ mm Hg}$. Physical examination demonstrates a markedly distended, tense, and visibly erythematous abdomen with absent bowel sounds. Capillary refill time is 4 seconds. Arterial blood gas analysis on room air shows a pH of 7.15, $p\text{CO}_2$ of $35\text{ mm Hg}$, and $\text{HCO}_3^-$ of $12\text{ mEq/L}$. An anteroposterior abdominal radiograph demonstrates extensive pneumatosis intestinalis and a distinct radiolucency over the liver shadow, indicating free intraperitoneal air. Which of the following is the most appropriate next step in the management of this patient?