RUQ pain, fevers, increased alkaline phosphatase and bilirubin. Except, sometimes, in the ICU where the gallbladder can become necrotic with no change in the transaminases.
Having or having had prior biliary disease, or having your biliary tract manipulated
- Parasites: Ascaris lumbricoides.
First, look for away cause of obstruction that you can relieve. Generally speaking, E. coli and B. fragilis can be used as stand ins for all community acquired gram negative rods and anaerobes, respectively. So kill the gram negative rods with third generation cephalosporins OR quinolones PLUS kill the anaerobes with metronidazole OR clindamycin.
There is too much resistance in E. coli to rely on piperacillin and ALL other penicillins if you do not have cultures validating susceptibility. You probably get the best results with drugs that good biliary levels, so my preference is ceftriaxone and metronidazole.
FYI, the other drugs that get good biliary levels are piperacillin (but no so much tazobactam) nafcillin and clindamycin. But the best drug, as always, is draining the pus. Monotherapy with a carbapenems OR penicillin/beta-lactamase inhibitors are used by some. Not me. If septic, maybe add a short course of gentamicin.
And how long to treat after the gallbladder is removed? Probably 4 days suffices (PubMed) if you goal is to prevent an SSI. The study out of France demonstrated that amoxicillin/clavulanate was no better than placebo for preventing post operative infections but their 15% infection rate suggests they have other issues in their practice (PubMed).
Sometimes a patient is too sick, septic, to go the OR and a tube is place in the gallbladder, a cholecystostomy, as a temporizing measure. Just know a cholecystostomy is associated with higher mortality (61.7%) than taking out the gallbladder (23%) (PubMed)
Beware the ICU gallbladder. A ventilated patient, often a diabetic, with fevers and a normal US of the gallbladder, but an elevated alp. Often a gangrenous gallbladder is found at surgery. Me? I can't figure out a HIDA, so I nearly always call a general surgeon.