Soru

A $76$-year-old woman is brought to the emergency department by her family due to severe, sudden-onset abdominal pain that started $3$ hours ago. She describes the pain as generalized, constant, and $10/10$ in intensity. She has had one episode of nonbilious emesis. Her medical history is significant for permanent atrial fibrillation, diet-controlled type 2 diabetes mellitus, and hypothyroidism. She admits to running out of her apixaban medication three weeks ago and has not taken it since. She takes levothyroxine daily.

Vital signs:
- Temperature: $37.4^\circ\text{C}$ ($99.3^\circ\text{F}$)
- Blood pressure: $105/65\text{ mm Hg}$
- Heart rate: $118/\text{min}$ and irregularly irregular
- Respiratory rate: $26/\text{min}$

Physical examination reveals a soft, non-distended abdomen. There is mild, diffuse tenderness to deep palpation, but no guarding, rigidity, or rebound tenderness. Bowel sounds are diminished.

Laboratory results:
- Leukocytes: $18,500/\text{mm}^3$
- Serum sodium: $138\text{ mEq/L}$
- Serum potassium: $4.2\text{ mEq/L}$
- Serum bicarbonate: $14\text{ mEq/L}$
- Blood urea nitrogen: $28\text{ mg/dL}$
- Serum creatinine: $1.2\text{ mg/dL}$
- Lactic acid: $5.8\text{ mmol/L}$ (normal: $0.5-2.2\text{ mmol/L}$)
- Thyroid-stimulating hormone (TSH): $0.1\text{ }\mu\text{U/mL}$ (normal: $0.4-4.0\text{ }\mu\text{U/mL}$)
- Free T4: $1.3\text{ ng/dL}$ (normal: $0.9-1.7\text{ ng/dL}$)

Arterial blood gas (room air):
- pH: $7.28$
- pCO2: $32\text{ mm Hg}$
- pO2: $88\text{ mm Hg}$

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