Acute cholecystitis

Acute cholecystitis, or inflammation of the gallbladder, usually comes about because of a gallstone being lodged in the cystic duct.

The cystic duct is the one that leaves the gallbladder and connects to the common bile duct. So let’s say this person’s gallbladder’s got a few gallstones in it, and they go to eat a hamburger, the small intestine secretes cholecystokinin, sometimes shortened to CCK, into the blood where it makes it’s way to the gallbladder, and signals it to squeeze out some bile to give it a hand with digestion of that hamburger.

The gallbladder contracts and one of these stones gets lodged right in the cystic duct, which blocks bile flow...now what?

Well this person probably start experiencing some pain, specifically midepigastric pain, which happens because the gallbladder’s trying to squeeze on a blocked duct...and just like if you squeezed a partly filled balloon with the end blocked off, it physically stretches out and irritates the nerves in the gallbladder and duct.

This can also lead to nausea and vomiting, which can last for long periods of time. And as the gallbladder squeezes more and more, the stone might get even more stuck, and at this point the bile, being stuck in the same place, or in a state of stasis, becomes a kind of chemical irritant, and causes the mucosa in the walls to start secreting mucus and inflammatory enzymes, which results in some inflammation, distention and pressure buildup.

At this point, there might also start to be some bacterial growth, most commonly E coli which is all over the gut, but also Enterococci, Bacterioides fragilis, and Clostridium, which can also be found there.

As it sort of balloons up, the pain might start to shift to the right upper quadrant, and it’ll be this kind of dull, achy pain that can even radiate up to the right scapula and shoulders.

After a while, bacteria starts invading into the gallbladder wall and eventually through the wall, causing peritonitis, inflammation of the peritoneum, which can cause what’s called rebound tenderness, where pain is brought on when pressure is actually taken off the belly rather than when it’s applied.

Here’s another physical exam trick, though. We know that while a patient takes in a deep breath, the diaphragm pushes down on the gallbladder.

You can apply pressure onto the abdomen to keep the abdominal contents from sliding downward . With the abdominal contents roughly pinned in place, you can ask a patient to take a deep breath and if the diaphragm pushes down on their gallbladder (which remember s pinned in place), that will cause pain, forcing the patient to stop breathing in further and that’d be a positive murphy’s sign which can help with diagnosis.

Finally, since the bacteria has started invading the mucosa and the tissue, the patient’s immune system kicks in, ramping up the neutrophils in the blood and leading to neutrophilic leukocytosis and likely also causing a fever.

At this point, one of two things can happen, first, the stone could fall out of the cystic duct, which is great, and then the symptoms and cholecystitis eventually subside, this actually happens in the majority of cases.

The other thing that could happen though is that the stone doesn’t fall out...And if that’s the case, pressure can keep building up, eventually so much so that it starts pushing down on the blood vessels supplying the gallbladder with blood, which means blood can’t get to the gallbladder and the tissue starts to get ischemic, leading to gangrenous cell death, which is cell death due to not having enough of a blood supply.

As the gallbladder walls weaken, it might eventually perforate or rupture. This causes sharp pain and if left untreated, could allow bacteria to get into the blood supply and cause sepsis.

If it’s allowed to get this far, it’s possible the patient needs a cholecystectomy, or a removal of the gallbladder. For some patients though, if the stone gets lodged further down in the common bile duct instead of the cystic ducts, it can start to block the flow of bile from the liver, because remember that the liver cells help produce bile, right?

If the liver cells keep producing bile but none of it can go anywhere because of this blockage, bile can start to back up into the liver, which increases pressure in the bile ducts, and causes the bile to eventually force its way through the tight junctions between the cells lining the bile ducts and make its way to the bloodstream, causing an increase in serum conjugated bilirubin (which is a component of bile) which leads to jaundice, or yellowed skin.

An important marker that might be found in someone’s blood that has cholecystitis is alkaline phosphatase, or ALP, this is an enzyme found in high amounts in the liver and bile ducts, so when bile backs up and pressure in the ducts increases, these cells can be damaged and die, and when they die they release their ALP which can then get into the blood.A diagnosis can be confirmed by ultrasound which can detect stones as well as a sonographic murphy sign which is abdominal tenderness from pressure of the ultrasound probe over the gallbladder.

Other ultrasound findings include gallbladder wall thickening, build up of sludge, and distention of the gallbladder or bile duct.

A more sensitive study is cholescintigraphy, sometimes referred to as a HIDA scan. In cholescintigraphy a radiolabeled marker is used to visualize the biliary system.

In the case of acute cholecystitis, the ducts are often blocked and the gallbladder can’t be seen. A blockage of the biliary system can also be seen with Endoscopic Retrograde Cholangiopancreatography or ERCP for short.

In ERCP, an endoscope with a camera is passed down the mouth and gastrointestinal tract until it reaches the pancreas. At that point, a contrast dye is injected into the pancreas and the dye is viewed through a fluoroscope.

Another approach is Magnetic Resonance Cholangiopancreatography, or MRCP, which visualizes the biliary system with the use of a magnetic resonance machine.Treatment of acute cholecystitis often includes supportive measures like intravenous fluids, pain management, and antibiotics.

Typically, the gallbladder is surgically in a procedure called a cholecystectomy, if it’s done laparoscopically it’s often called a lap chole for short.

All right, as a quick recap … Acute cholecystitis, is inflammation of the gallbladder that is caused by gallstones getting lodged in the cystic duct.

Often the disease improves on its own once the stones fall out of the duct. If the stones stay in place there can be a buildup of pressure that can lead to gallbladder ischemia, and even rupture.

The disease is often diagnosed by ultrasound and treated with a cholecystectomy. Thanks for watching If you're interested in a deeper dive on this topic take a look at osmosis dot org where we have flashcards questions and other awesome tools to help you learn medicine Otherwise you can always support us by donating on patry in subscribing to our