What is the appropriate initial approach and management for a [AGE]-year-old female patient presenting with right upper quadrant (RUQ) pain?

Initial Approach to Right Upper Quadrant Pain in Female Patients

Order an abdominal ultrasound immediately as the first-line imaging study for any female patient presenting with right upper quadrant pain. 1

Focused Clinical Assessment

Obtain the following specific clinical information while awaiting ultrasound:

• Pain characteristics: Document onset (acute vs. chronic), radiation pattern to right shoulder or back (suggests biliary colic), and whether pain is constant or episodic 1
• Murphy's sign: Elicit this finding on physical examination, as it is highly suggestive of acute cholecystitis 1
• Fever and vital signs: Check for fever, tachycardia, or hypotension, which suggest infection or sepsis requiring urgent intervention 1
• Associated symptoms: Record presence of jaundice, nausea, vomiting, and changes in bowel habits 1
• Pregnancy status: Obtain a pregnancy test for all women of reproductive age before any imaging to rule out ectopic pregnancy 1, 2
• Medication history: Document all medications from the past 6 weeks, including prescription drugs, over-the-counter medications, and herbal supplements 1

Initial Laboratory Testing

Order the following labs concurrently with ultrasound:

• Complete blood count to assess for leukocytosis indicating infection 1
• Liver function tests including ALT, AST, alkaline phosphatase, GGT, and bilirubin to evaluate for biliary obstruction or hepatic pathology 1
• Pancreatic enzymes (amylase and lipase) to exclude pancreatitis 1

Imaging Algorithm

Ultrasound is the primary imaging modality with 96% accuracy for diagnosing gallstones and should be performed first in all patients with RUQ pain. 1 Ultrasound rapidly identifies gallstones, gallbladder wall thickening, pericholecystic fluid, and sonographic Murphy sign. 1 This approach is cost-effective, avoids radiation exposure, and provides immediate diagnostic information. 1, 3

When to Proceed to CT After Ultrasound

Order CT abdomen with IV contrast in the following scenarios:

• Ultrasound findings are equivocal or nondiagnostic 1
• Complications of cholecystitis are suspected, such as perforation, gas formation, intraluminal hemorrhage, or gangrenous cholecystitis 4, 1
• Alternative diagnoses need evaluation, as CT provides superior detection of gallbladder wall enhancement, adjacent liver parenchymal hyperemia, and complications 4, 1

When to Consider Advanced Imaging

• Cholescintigraphy (Tc-99m hepatobiliary scan): Order when ultrasound and clinical findings remain equivocal for acute cholecystitis, as this test has 96% sensitivity and 90% specificity 2
• MRI abdomen with MRCP: Consider when other imaging tests are equivocal, the patient is difficult to examine with ultrasound (obesity), detailed evaluation of the biliary tree is needed, or in pregnant patients to avoid radiation 4, 1, 2

Differential Diagnosis Framework

While acute cholecystitis is the most common cause of RUQ pain, over one-third of patients do not have acute cholecystitis. 5, 3 Consider these alternative diagnoses:

Biliary Causes

• Biliary colic: Episodic severe pain from gallstones causing transient cystic duct obstruction 2
• Choledocholithiasis: Common bile duct stones causing obstruction and elevated liver enzymes 2
• Acute cholangitis: Requires the triad of jaundice, fever/chills, and RUQ pain, plus biliary dilatation on imaging 2

Critical "Can't Miss" Diagnoses

• Ruptured ectopic pregnancy: Life-threatening condition requiring urgent intervention 2
• Perforated gallbladder with peritonitis: Requires immediate recognition and surgical intervention 2
• Mesenteric ischemia: Life-threatening vascular emergency 2
• Ruptured hepatic abscess or tumor 2

Other Common Causes

• Hepatic pathology: Hepatitis, hepatic abscess, or hepatic mass 3
• Pancreatic disease: Pancreatitis or pancreatic mass 3
• Renal pathology: Pyelonephritis, renal calculi, or renal mass 3
• Gastrointestinal causes: Peptic ulcer disease, gastroenteritis, or bowel obstruction 4

Critical Pitfalls to Avoid

• Do not skip ultrasound and proceed directly to CT, as ultrasound provides rapid, cost-effective diagnosis without radiation exposure 1
• Do not order CT without IV contrast for suspected cholecystitis, as critical findings like gallbladder wall enhancement and adjacent liver parenchymal hyperemia cannot be detected without contrast 1, 2
• CT has only 75% sensitivity for gallstones, so negative CT does not exclude cholelithiasis—ultrasound remains superior for stone detection 1, 2
• Do not assume sludge alone equals cholecystitis, as critically ill patients commonly have gallbladder abnormalities including sludge without true acute cholecystitis 2
• Ultrasound has only 88% sensitivity for acute cholecystitis—if clinical suspicion is high despite negative or equivocal ultrasound, proceed to HIDA scan or CT 2

Immediate Management While Awaiting Imaging

In patients with suspected acute cholecystitis or cholangitis based on clinical presentation:

• NPO status 6
• IV fluid resuscitation 6
• Broad-spectrum antibiotics if fever and leukocytosis are present 6
• Surgical consultation should not be delayed while awaiting additional imaging if clinical diagnosis of acute cholecystitis is evident 2

Urgent Referral Indications

Refer immediately to the emergency department or acute surgical service if fever with leukocytosis suggesting acute cholecystitis or cholangitis is present. 2