Obtain an Abdominal Ultrasound Immediately
For a vitally stable patient presenting one week after an RTA with persistent mild right upper quadrant pain, the most appropriate initial step is to perform an abdominal ultrasound to evaluate for delayed hepatobiliary injury or other occult pathology.
Clinical Rationale
The one-week delay between trauma and presentation is critical here. While the patient appears stable now, blunt abdominal trauma from motor vehicle accidents carries significant risk for delayed presentation of serious injuries, including hepatic lacerations, splenic injuries, bowel perforations, and retroperitoneal hemorrhage that may not manifest immediately with hemodynamic instability 1. Right upper quadrant pain specifically raises concern for hepatobiliary injury, which occurs frequently in RTAs and can progress to life-threatening hemorrhage 1.
Why Ultrasound First in This Specific Context
- Ultrasound is the recommended initial imaging modality for right upper quadrant pain evaluation according to the American College of Radiology 2
- In a vitally stable patient presenting to an outpatient clinic (not an emergency department), ultrasound provides immediate bedside assessment without requiring IV contrast or radiation exposure 2
- Ultrasound can rapidly identify free fluid, solid organ injuries, or biliary pathology that would necessitate urgent referral 3
- The clinical setting (clinic visit, not ED) and vital stability allow for this stepwise approach rather than immediate CT 2
When to Escalate Based on Ultrasound Findings
If ultrasound demonstrates:
- Free intraperitoneal fluid → immediate ED referral for CT with IV contrast and potential surgical intervention 3, 1
- Solid organ injury (liver laceration, subcapsular hematoma) → ED referral for CT characterization and admission for observation 3, 1
- Negative ultrasound but persistent symptoms → proceed to CT with IV contrast, as FAST ultrasound has notably low sensitivity (56-71%) for detecting intra-abdominal injuries in blunt trauma 1
Why Not Direct ED Referral or Blood Work Alone
- ED referral without initial assessment wastes resources if the ultrasound is completely negative and symptoms are mild 4
- Blood work alone cannot exclude significant pathology - hemoglobin may be normal even with contained hepatic injuries or developing complications 3
- However, never rely on clinical examination alone in blunt abdominal trauma from high-energy mechanisms like RTAs, as up to 75% of patients have associated injuries that may not be clinically apparent initially 1
Critical Pitfall to Avoid
Do not delay imaging for "observation" in trauma patients with persistent symptoms - occult injuries can deteriorate rapidly, and delayed presentations of bowel injuries and other pathology occur in 0.2-0.5% of cases even with negative initial evaluation 1. The fact that this patient has persistent pain one week post-trauma mandates imaging evaluation 1, 2.
If Ultrasound is Unavailable in Your Clinic
If ultrasound is not immediately available, then refer to the emergency department for CT abdomen/pelvis with IV contrast, as CT provides comprehensive evaluation of all abdominal organs, the retroperitoneum, and can detect active extravasation of contrast indicating ongoing hemorrhage 1. The negative predictive value of CT for need for surgical intervention is 99.63% 1.