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The Edge: Acute Cholecystitis
The Edge is a monthly blog series developed by EMS World and FlightBridgeED that features top EMS medical directors exploring the intricacies of critical care in EMS practice. In this installment FlightBridgeED Chief Medical Director Jeffrey Jarvis, MD, discusses acute cholecystitis.
An overweight but otherwise healthy 24-year-old female calls 9-1-1 after the sudden onset of abdominal pain with nausea and vomiting. She tells you this pain came on about 30 minutes after she ate a breakfast burrito. It is localized to her mid-upper abdomen. It is constant and intense with radiation to her right shoulder blade. Her vomit has no blood. She denies any fever and says this has never happened before.
On exam you detect tenderness to palpation in her right upper quadrant. Palpation with inspiration is sufficiently painful that she stops her inspiration. You detect no masses on exam. Her skin is dry without jaundice. Vital signs are BP 135/78, HR 108, RR 24, temperature 97.9ºF, SpO2 98% on room air, and EtCO2 36. You perform a point-of-care ultrasound of her right upper quadrant (Figure 1). Her pain score is initially an 8 and continues to be a 6 after two 100-mcg doses of fentanyl, and her nausea continues despite 8 mg of ondansetron. Fortunately the nausea is relieved by 1.25 mg of droperidol. You notify the hospital of your findings and impression of acute cholecystitis.
Introduction
Abdominal pain is a common complaint and results in 3.4% of U.S. 9-1-1 calls.1 Acute cholecystitis accounts for 3%–4% of all hospital admissions among patients with abdominal pain. Cholecystitis is the inflammation of the gallbladder and one of several diseases on a spectrum of biliary disease that includes cholelithiasis, choledocholithiasis, and cholangitis. Biliary disease is almost twice as common in women as men and is more common in Hispanics and Native Americans. Other risk factors include obesity, increasing age, pregnancy, and hormone use.
The gallbladder is located just under the liver in the right upper abdominal quadrant and is responsible for storing bile. Up to one liter of bile is made in the liver every day.2 Some passes into the gallbladder for storage via the hepatic and cystic ducts (Figure 2). Bile is needed for the absorption of fats during digestion and removal of cholesterol and red blood cell breakdown products. When fatty foods are ingested, the hormone cholecystokinin is released and leads to contraction of the gallbladder, which expels bile through the cystic duct, the common bile duct, and eventually the duodenum. Just prior to entering the duodenum, the common bile duct is joined by the pancreatic duct. In the absence of bile, fat will pass unabsorbed through the intestines and into stool. This can cause oily diarrhea and increased flatulence, including unfortunate wardrobe contamination.
Most gallstones are made of cholesterol, but a minority are from bile pigment.3 These stones can form in up to 20% of the population. If the stones remain in the gallbladder and do not obstruct its neck or the bile or cystic ducts, there is usually no pain. In fact, many people will not be aware they have stones. If the stones lead to cystic duct obstruction, the gallbladder can become distended and inflamed as it attempts to contract against the obstruction. This distention is painful. If the obstruction resolves, the pain will resolve. This transient pain without any other complication is known as biliary colic or symptomatic cholelithiasis (-lithiasis refers to stones).
Acute cholecystitis is the inflammation of the gallbladder leading to persistent pain. Cholecystitis is most commonly caused by a stone obstructing the cystic duct at the neck of the gallbladder. Choledocholithiasis is similar to cholecystitis, but the obstruction is in the common bile duct. If there is biliary obstruction and resulting inflammation of the biliary tree (hepatic ducts), this is called ascending cholangitis. Patients with cholangitis typically appear acutely ill, while those with cholelithiasis or cholecystitis, although appearing in distress, do not classically look toxic.
History and Physical Exam Findings
The classic textbook description of acute cholecystitis is an overweight female patient of reproductive age who presents with acute onset of abdominal pain and vomiting. The pain appears 20–30 minutes after eating a fatty meal. It is described as sharp/stabbing and may radiate through the abdomen to the right scapula. There may have been prior episodes that occurred after eating fatty meals and spontaneously resolved.
On exam the patient will have right upper quadrant tenderness with Murphy’s sign. Murphy’s sign is present when tenderness to palpation is sufficient to interrupt inspiration. It is often absent in cholecystitis (sensitivity is 65%) but when present is relatively specific (87%) for cholecystitis and has a likelihood ratio when positive of 2.8.4 Ongoing pain for more than a few hours is likely an indication of acute cholecystitis rather than simple cholelithiasis. The most sensitive finding (77%) for cholecystitis is nausea, and the most specific (87%) is Murphy’s sign. The combination of right upper quadrant pain, fever, and jaundice is Charcot’s triad. Add hypotension and altered mental status, and you get Reynolds’ pentad. Both are frequently absent but when present are specific (better than 93%) for cholangitis.5
Many patients of course have not read our textbooks, and thus the classic textbook presentation often fails to appear. Patients may have epigastric pain or even no pain, with only nausea and vomiting. For medics who enjoy taking a good history, there may be a history of increased flatulence and even soiled underwear with pale-grayish foul-smelling stools. This is a result of decreased fat absorption. If you’re old enough to remember (or have experienced) the poorly thought-out marketing campaign for the Wow! brand of “fat free” potato chips, you have a good idea of what happens when fat is not absorbed.6 And if you don’t remember, just search olestra for an interesting read.
Diagnosis and Treatment
EMS management of biliary disease is similar to all patients with abdominal pain: The priority is on assessing for life-threatening emergencies, providing analgesia, and making a differential diagnosis. The differential for patients with epigastric or right upper quadrant pain with vomiting should include biliary disease, pancreatitis, acute coronary syndrome (ACS), gastroesophageal reflux disease (GERD), peptic ulcer disease, pneumonia, aortic dissection, and diabetic ketoacidosis. Most of these diagnoses can become much less likely through history alone (a patient with pneumonia may have RUQ pain on inspiration but is also likely to have cough and shortness of breath, which are unlikely with biliary disease). A 12-lead ECG is prudent in all patients with nausea or abdominal pain but particularly those with RUQ pain, since this may be a sign of an inferior MI.
Analgesia is an important intervention. Administration of opioids is humane for patients with pain and does not decrease the diagnostic accuracy of the emergency department evaluation.7–10
Evaluation and diagnosis of biliary disease usually begins with ultrasound. The classic diagnostic findings of acute cholecystitis include gallstones with echographic “shadowing,” pericholecystic fluid, wall thickening, and in cases of choledocholithiasis, dilation of the common bile duct (Figure 3). Laboratory evaluation includes CBC, evaluation of liver function tests, and bilirubin. Labs will be normal in cholelithiasis and many cases of cholecystitis, but cholangitis is likely to show elevations in white blood cells, AST, ALT, and total bilirubin.
Treatment of cholelithiasis and cholecystitis is typically laparoscopic cholecystectomy; however, this may be delayed for cholelithiasis. Cholangitis typically needs antibiotics and ERCP (endoscopic retrograde cholangiopancreatography), an endoscopic procedure in which a gastroenterologist inserts a tube through the mouth, navigates down through the stomach and duodenum, and can remove stones obstructing the bile or pancreatic duct.
Point-of-care ultrasound (POCUS) is increasingly common in EMS and can improve the accuracy of our clinical impressions of abdominal pain. Evaluation of the right upper quadrant is fairly straightforward and takes little time. Identification of gallstones by EMS can help improve ED throughput and decrease length of stay and time to diagnosis and treatment.
Case Conclusion
Your patient’s pain persists in the ED. Your findings are confirmed with a formal ultrasound that reveals multiple gallstones with shadowing and wall thickening but no pericholecystic fluid or ductal dilation. Her lab values are normal except for a mild elevation of her white blood cell count (12,000). Notably, her liver function tests and total bilirubin are normal.
She is diagnosed with acute cholecystitis and given a surgical consult. She has an uncomplicated laparoscopic cholecystectomy performed later that day, which reveals an inflamed gallbladder with many stones (Figure 4). Her pain resolves postoperatively, and she goes home that evening with no complications.
Sidebar: A Statistics Explainer
Likelihood ratios greater than 1 increase the likelihood of a diagnosis being present, and those between 0–1 decrease the likelihood. Similarly, a highly sensitive test will be positive when a disease is present. As an example, a test with 99% sensitivity will be positive in 99% and negative in 1% of patients with the disease. This means if a highly sensitive test is negative, the patient likely does not have the disease. In other words, highly sensitive tests are useful for ruling out disease. A mnemonic for this is SnOut (SeNsitivity rules OUT disease).
A highly specific test, on the other hand, will be negative when disease is absent. As an example, a test with 99% specificity will be negative in 99% of patients and positive in 1% of patients who do not have the disease. In other words, highly specific tests are useful for ruling in disease. The mnemonic for this is SpIN (SPecificity rules IN disease).
Jeffrey L. Jarvis, MD, MS, EMT-P, FACEP, FAEMS, is chief medical director for FlightBridgeED, LLC and cohost of the FlightBridgeED EMS Lighthouse Project Podcast.
References
1. Ambulance Response: How Often Are Potentially Life-Saving Interventions Performed. Prehosp Emerg Care. Published online August 7, 2020:1-7. doi:10.1080/10903127.2020.1797963
2. Haines EJ, Oyama LC. Disorders of the Liver and Biliar Tract. In: Walls RM, Hockenberger R, Gausche-Hill M, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed. Elsevier; 2018:1083-1103.
3. Gill RM, Kakar S. Chpt 18 - Liver and Gallbladder. In: Robbins & Cotran Pathologic Basis of Diesase. 10th ed. Elsevier; 2021:823-880. Accessed October 12, 2021. https://www.clinicalkey.com/#!/content/book/3-s2.0-B9780323531139000182
4. Trowbridge RL, Rutkowski NK, Shojania KG. Does This Patient Have Acute Cholecytitis? JAMA. 2003;289(1):80-86.
5. Rumsey S, Winders J, MacCormick AD. Diagnostic accuracy of Charcot’s triad: a systematic review. ANZ Journal of Surgery. 2017;87(4):232-238. doi:10.1111/ans.13907
6. Glass S, Glass S. What Were They Thinking? The Chips That Sent Us Running To The Loo. Fast Company. Published January 17, 2012. Accessed October 18, 2021. https://www.fastcompany.com/1809002/what-were-they-thinking-chips-sent-us-running-loo
7. Manterola C, Vial M, Moraga J, Astudillo P. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011;(1):CD005660. doi:10.1002/14651858.CD005660.pub3
8. Pace S, Burke TF. Intravenous morphine for early pain relief in patients with acute abdominal pain. Acad Emerg Med. 1996;3(12):1086-1092.
9. Ranji SR, Goldman LE, Simel DL, Shojania KG. Do Opiates Affect the Clinical Evaluation of Patients With Acute Abdominal Pain? JAMA. 2006;296(14):1764-1774.
10. Yuan Y, Chen JY, Guo H, et al. Relief of abdominal pain by morphine without altering physical signs in acute appendicitis. Chin Med J (Engl). 2010;123(2):142-145.
Comments
I wish to extend my great thanks for your undoubted explanation on acute cholecystitis which is a common health problem in elderly patients. Me being a medical herbalist, this information i have got from you "i hope" it will help me diagnose and treat my patients who will come in my clinic with such complaint and having the signs and symptoms you have indicated.
Hoping to get more health information from you, i thank you once more and wish a happy new year.
I remain yours in Human health care.
—Dr. Ndahira Assuman