Question

Following a three-day hospitalization for conservative management of a small bowel obstruction, a $72$-year-old man undergoes acute clinical deterioration. He initially presented with colicky abdominal pain, profound abdominal distension, and failure to pass flatus. His medical history includes paroxysmal atrial fibrillation, for which he takes apixaban, and his surgical history includes a sigmoid colectomy performed a decade ago for complicated diverticulitis. During the first $48$ hours of admission, he remained afebrile and was managed with a nasogastric tube and intravenous crystalloid therapy.

Over the past $2$ hours, the patient's nurse reports that he has become increasingly lethargic and is now complaining of a new, relentless, severe aching pain centered in the periumbilical region.

Current vital signs demonstrate a temperature of $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), a blood pressure of $92/54\text{ mmHg}$, a pulse of $122/\text{min}$, and respirations of $24/\text{min}$.

Physical examination reveals a markedly distended, rigid abdomen with absent bowel sounds. Palpation elicits involuntary muscle spasm and severe pain upon quick release of the examining hand.

Laboratory evaluation reveals:
Leukocyte count: $18,200/\text{mm}^3$ ($85\%$ neutrophils, $10\%$ bands)
Serum bicarbonate: $16\text{ mEq/L}$
Lactate: $4.2\text{ mmol/L}$

Which of the following is the most appropriate next step in the management of this patient?