A 74-year-old arrived at the ED experiencing bright red rectal bleeding when using the toilet.

In this case, a CRNA provided anesthesia for an urgent endoscopic procedure. To select the appropriate codes, we consider both the anesthesia code for the procedures performed and the modifiers relevant to the CRNA’s role and the patient’s physical status:

1. 00813: This CPT® code covers "Anesthesia for lower intestinal endoscopic procedures, endoscope introduced distal to duodenum," which is appropriate since the colonoscopy extended to the ileum and into the lower duodenum. 00731 (anesthesia for upper GI endoscopy) would not fully apply, as the main procedure targeted lower intestinal areas as well.

2. QZ Modifier: Indicates the anesthesia was performed by a CRNA without medical direction by an anesthesiologist, which aligns with the scenario where the CRNA independently administered anesthesia.

3. P3 Modifier: Reflects the physical status of "severe systemic disease" for this patient, as she has both end-stage renal failure and myelodysplastic syndrome.

4. 99100: This code is added to reflect "special anesthesia circumstances" given the patient’s extreme frailty (platelet count of 3,000), which warrants additional consideration.

5. 99140: Used for emergency conditions, which applies here due to the urgent nature of the bleeding investigation.

Thus, 00813-QZ-P3, 99100, 99140 accurately reflects the anesthesia services provided by the CRNA in this emergency scenario.