Question

An evaluation is requested in the emergency department for a 54-year-old woman reporting two days of severe, colicky abdominal pain accompanied by progressive swelling of her abdomen. She notes an inability to pass stool or flatus over the past 24 hours and has experienced three episodes of bilious emesis today. Her past surgical history is notable for an open total abdominal hysterectomy performed five years ago. On presentation, her temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), pulse is $98/\text{min}$, and blood pressure is $110/70\text{ mmHg}$. Abdominal examination demonstrates marked distension and tympany with hyperactive, high-pitched bowel sounds. Palpation reveals diffuse mild tenderness, but there is no guarding, rigidity, or rebound tenderness. Initial laboratory evaluations show:

Leukocyte count: $11,200/\text{mm}^3$
Serum sodium: $136\text{ mEq/L}$
Serum potassium: $3.2\text{ mEq/L}$
Serum chloride: $96\text{ mEq/L}$
Serum bicarbonate: $28\text{ mEq/L}$
Serum lactate: $1.1\text{ mmol/L}$ (normal: $0.5$-$2.2\text{ mmol/L}$)

Arrange the following management steps in the most appropriate chronological sequence for this patient.