Updated July 2026 · 8 min read

Acalculous Cholecystitis for ICU Nurses 2026 — The Gallbladder That Rots Without a Stone

Part of the ICU Emergencies Hub — browse every related guide in one place.

You have a patient who has been in the unit for a week — trauma, sepsis, a big surgery, on the ventilator, tube-fed or NPO on TPN — and they start to slide. The white count climbs, they spike a fever, the pressor requirement creeps up, and everyone starts hunting for the source. Blood cultures, urine, the lines, the lungs. What is easy to forget, because the patient cannot point to their belly and the classic textbook story does not apply, is that the gallbladder itself can be the source. Acute acalculous cholecystitis is a gallbladder that becomes inflamed, ischemic, and sometimes frankly gangrenous without any gallstones at all — a disease almost unique to the critically ill. It is a classic occult source of ICU sepsis, and because the patient often cannot report the pain that would give it away, catching it is a nursing and clinical vigilance problem as much as a surgical one.

Why the critically ill grow a sick gallbladder

The gallbladder's job is to fill with bile and squeeze it out when you eat. In a critically ill patient, that cycle stops. Someone who is NPO for days, fed intravenously, or not absorbing enterally never gets the fatty-meal signal (cholecystokinin) that triggers gallbladder emptying, so bile sits and thickens into sludge. At the same time, the shock state that put them in the unit — sepsis, hypotension, low flow, vasopressors squeezing the splanchnic circulation — starves the gallbladder wall of blood. Add fever-driven dehydration and thickened bile, and you have a stagnant, ischemic organ that becomes an ideal culture medium. Bacteria overgrow, the wall becomes inflamed and then necrotic, and unlike stone disease, there is no obstructing stone to blame — the whole process is stasis plus ischemia. This is why acalculous cholecystitis clusters in exactly the sickest patients: major trauma and burns, prolonged mechanical ventilation, extended TPN, cardiac surgery, and severe sepsis. The very things that keep a patient in the ICU are the things that set up their gallbladder to fail.

The hard part: recognizing it in someone who cannot complain

In an awake outpatient, cholecystitis announces itself with right-upper-quadrant pain, a positive Murphy's sign, and nausea after fatty food. Your sedated, intubated ICU patient offers none of that. Instead the presentation is frustratingly nonspecific: a new or worsening fever, a climbing white count, rising bilirubin or liver enzymes, a lactate that will not clear, or simply sepsis without an obvious source after the usual suspects come back negative. Sometimes the only physical clue is fullness or guarding in the right upper quadrant, or discomfort when you turn or reposition the patient. Because the disease is occult and moves quickly, the practical rule is that acalculous cholecystitis belongs on the differential for any deteriorating, septic ICU patient whose cultures and chest imaging do not explain the picture — especially if they have been NPO or on TPN for days.

Diagnosis and the treatment that fits an unstable patient

The first-line test is a bedside right-upper-quadrant ultrasound, looking for a thickened gallbladder wall, pericholecystic fluid, sludge, and a distended gallbladder — without stones. Because these findings can be equivocal in the critically ill, a HIDA scan (which shows the gallbladder failing to fill) or CT may be added. The treatment decision hinges on how sick the patient is. A stable patient may go to the operating room for cholecystectomy, but many ICU patients are far too unstable for anesthesia and a laparotomy. For them, the workhorse intervention is a percutaneous cholecystostomy tube — interventional radiology places a drain directly into the gallbladder through the skin, decompressing and draining the infected bile without general anesthesia. Combined with broad-spectrum antibiotics that cover gut flora and fluid resuscitation, this often turns the septic picture around within a day or two, and definitive gallbladder removal can wait until the patient recovers. As a nurse, your role after the tube is placed is to secure and monitor the drain, track output and its character, watch for signs of bile leak or ongoing sepsis, and continue the sepsis bundle.

The nursing bottom line

Acute acalculous cholecystitis is the gallbladder emergency that hides inside critical illness: stasis from being NPO or on TPN plus ischemia from shock produces an inflamed, sometimes gangrenous gallbladder with no stone to explain it. Its danger is that it appears as nonspecific, worsening sepsis in a patient too sick or sedated to report abdominal pain, and it perforates quickly. Keep it on the list for any deteriorating long-stay ICU patient with sepsis of unknown source, push for a right-upper-quadrant ultrasound when the usual cultures are unrevealing, and know that the definitive move for the unstable patient is usually a percutaneous cholecystostomy drain plus antibiotics rather than the OR. Recognizing the gallbladder as the hidden source is one of those catches that changes the whole trajectory of an ICU course.

Related:

Educational content for licensed clinicians. Always follow your facility's protocol and provider orders. Not medical advice.