By John T. Moeller MD, Seth Lotterman MD and Meghan Kelly Herbst, MD, FACEP
A 27-year-old healthy female on Depo-Provera presented to the ED with constant, sharp, non-radiating right upper quadrant (RUQ) pain for three days. The pain was unchanged with food intake, and was associated with nausea and one episode of non-bloody, non-bilious emesis on the day prior to presentation. She also reported pleuritic right lower chest pain, lightheadedness, and chills. On further review of systems, she denied sore throat, shortness of breath, cough, rash, urinary changes, diarrhea, and bloody stools. Social history was unremarkable.
On exam, she was afebrile (36.8C), with blood pressure 149/88, heart rate 51, respiratory rate 18, and oxygen saturation 100%. She appeared uncomfortable. Her head, neck, heart, and lung exams were unremarkable. Her abdomen was soft, non-distended, with RUQ tenderness and a positive Murphy’s sign. There was no guarding or rebound tenderness. The remainder of her physical exam was unremarkable.
A point-of-care ultrasound (POCUS) demonstrated gallbladder wall thickening, pericholecystic fluid, and a sonographic Murphy’s sign without evidence of gallstones. Liver function tests, complete blood count, and basic metabolic panel were all within normal limits. Urine pregnancy was negative. Urinalysis was negative for infection. A formal hepatobiliary ultrasound confirmed the POCUS findings consistent with acalculous cholecystitis, with the common bile duct diameter measured at 0.4 cm. Surgery was consulted.
Given her pleuritic pain, light-headedness and her increased risk of thrombosis in the setting of Depo-Provera injections, a high sensitivity d-dimer was sent and returned elevated at 5276 ng/mL (the cutoff for exclusion of venous thromboembolism is < 230 ng/ml). Of note, the patient had a negative d-dimer of < 150 ng/mL at an unrelated ED visit 3 months prior. On account of the unusual presentation of acalculous cholecystitis in an otherwise healthy woman, surgery recommended a computed tomography (CT) scan of the abdomen and pelvis to rule out intra-abdominal inflammatory changes, fluid collections, or other pathology. A CT angiogram of the chest was added to exclude pulmonary embolism. All imaging was negative for acute intra-pulmonary and intra-abdominal pathology other than the abnormal gallbladder findings. The patient was taken to surgery, with a postoperative diagnosis of acalculous cholecystitis.
Days after discharge, the patient was readmitted for a new-onset tonic-clonic seizure and was diagnosed with posterior reversible encephalopathy syndrome (PRES), nephritis and malignant hypertension. After extensive work up for systemic disease, including autoimmune serology, HIV, EBV, hepatitis, vasculitis, and malignancy, she has undergone outpatient workup and treatment for suspected systemic lupus erythematosus (SLE) after positive ANA and DS DNA antibody results.
Abdominal pain is the most common presenting complaint to emergency departments, accounting for nearly 10 million emergency visits alone in 2013, or 7.7% of all visits.1 Of the estimated 700,000 cholecystectomies performed annually in the United States, > 90% are for acute calculous cholecystitis, and 95% of patients with acute cholecystitis will have associated gallstones.2 POCUS of the RUQ has become a safe, cost-effective imaging modality of choice for guiding the differentiation of medical and surgical causes of RUQ pain.
Signs of acute cholecystitis on POCUS include: cholelithiasis, a sonographic Murphy’s sign (the presence of maximal tenderness elicited over a sonographically localized gallbladder), gallbladder wall thickening, and pericholecystic fluid.3-5 Gallbladder wall thickening is defined as wall thickness > 0.3-0.5cm.3,4,6,7 The combination of gallstones and a sonographic Murphy’s sign is both specific and sensitive for acute cholecystitis, with a positive predictive value (PPV) of 92%. The addition of gallbladder wall thickening increases the PPV to 95%.3 Studies have demonstrated that emergency physicians diagnose acute cholecystitis with POCUS with similar sensitivity and specificity to formal radiology studies at 87% and 82%, respectively, for emergency physicians as compared to 83% and 86%, respectively, for radiology-performed studies.4