Acute calculous cholecystitis

Red Flags

Cholangitis (Charcot's triad: fever, jaundice, RUQ pain) — emergency ERCP within 24 h; broad-spectrum antibiotic; admit^[1]
Gangrenous or perforated cholecystitis (peritonism, gas in gallbladder wall, sepsis) — emergency cholecystectomy or percutaneous cholecystostomy^[1]
Acute cholecystitis with sepsis or organ dysfunction — sepsis pathway; urgent source control via early cholecystectomy or percutaneous drainage^[1]
Pregnancy with acute cholecystitis — laparoscopic cholecystectomy any trimester preferred over conservative management; multidisciplinary care^[1]

First-line treatment

Interventions

Early laparoscopic cholecystectomy^[1]
Within 1 week of symptom onset — preferred over delayed surgery; reduces hospital stay, recurrence, and complications; convert to open if anatomy unclear or fundus-first dissection
Risk stratification (TG18 grades I-III)^[1]
Grade I (mild): early laparoscopic cholecystectomy. Grade II (moderate): early laparoscopic cholecystectomy if expert centre, or after antibiotic stabilisation. Grade III (severe): organ-system support, percutaneous cholecystostomy if cholecystectomy too risky, delayed cholecystectomy after recovery
Percutaneous cholecystostomy (rescue)^[1]
Critically ill or high-risk (severe sepsis, decompensated heart failure, severe respiratory disease) where surgery cannot be tolerated; bridge to delayed cholecystectomy or definitive in unfit patients
Common bile duct evaluation^[1]
Suspected choledocholithiasis (raised LFT, dilated CBD, cholangitis): MRCP or EUS first; pre-operative ERCP if confirmed; combined ERCP-cholecystectomy or laparoscopic CBD exploration
Antibiotic duration^[1]
Mild cholecystitis after cholecystectomy: stop within 24 h. Severe or perforated: 4–7 days post-source control. Cholangitis: 4–7 days after biliary drainage achieved (longer if persistent infection or bacteraemia)

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Co-amoxiclav (community-acquired, mild)^[1]	Aminopenicillin + beta-lactamase inhibitor	1.2 g IV every 8 h; switch to oral 625 mg TDS once tolerating diet	Per local protocol	First-line for mild community-acquired cholecystitis without severity features; review at 48 h with cultures
Piperacillin-tazobactam^[1]	Beta-lactam + beta-lactamase inhibitor	4.5 g IV every 6–8 h	Per local protocol	Moderate-severe or healthcare-associated cholecystitis; broad gram-positive, gram-negative, anaerobic; renal dose adjustment
Ceftriaxone + metronidazole^[1]	Third-generation cephalosporin + nitroimidazole	Ceftriaxone 1–2 g IV daily + metronidazole 500 mg IV every 8 h	Ceftriaxone 50–80 mg/kg/day; metronidazole 7.5 mg/kg every 8 h	Alternative for mild-moderate community-acquired; oral switch to cefuroxime + metronidazole when improving
Meropenem (severe / ESBL risk)^[1]	Carbapenem	1 g IV every 8 h	20 mg/kg every 8 h	Reserve for severe cholangitis, ESBL coverage, prior multi-resistant organism; renal dose adjustment

Co-amoxiclav (community-acquired, mild)^[1]

Aminopenicillin + beta-lactamase inhibitor

Adult: 1.2 g IV every 8 h; switch to oral 625 mg TDS once tolerating diet
Paediatric: Per local protocol

First-line for mild community-acquired cholecystitis without severity features; review at 48 h with cultures

Piperacillin-tazobactam^[1]

Beta-lactam + beta-lactamase inhibitor

Adult: 4.5 g IV every 6–8 h
Paediatric: Per local protocol

Moderate-severe or healthcare-associated cholecystitis; broad gram-positive, gram-negative, anaerobic; renal dose adjustment

Ceftriaxone + metronidazole^[1]

Third-generation cephalosporin + nitroimidazole

Adult: Ceftriaxone 1–2 g IV daily + metronidazole 500 mg IV every 8 h
Paediatric: Ceftriaxone 50–80 mg/kg/day; metronidazole 7.5 mg/kg every 8 h

Alternative for mild-moderate community-acquired; oral switch to cefuroxime + metronidazole when improving

Meropenem (severe / ESBL risk)^[1]

Carbapenem

Adult: 1 g IV every 8 h
Paediatric: 20 mg/kg every 8 h

Reserve for severe cholangitis, ESBL coverage, prior multi-resistant organism; renal dose adjustment

Safety-net

Severe abdominal pain, fever, vomiting, or yellowing eyes after a recent gallstone episode — same-day medical review^[1]
After cholecystectomy: most return to normal activity within 1–2 weeks; persistent jaundice, severe pain, fever, or worsening symptoms warrant review^[1]
Avoid high-fat meals during recovery; symptoms typically improve over weeks; bile-salt diarrhoea may settle with reduced fat intake^[1]

Referral criteria

All acute cholecystitisGeneral surgery for early laparoscopic cholecystectomy^[1]
Cholangitis or septic cholecystitisEmergency department with surgery and gastroenterology / interventional radiology^[1]
High-risk surgical candidate or grade III TG18 with severe organ dysfunctionTertiary HBP / interventional radiology for percutaneous cholecystostomy^[1]
Suspected choledocholithiasis with dilated CBD or raised LFTsGastroenterology / HBP for MRCP/EUS and ERCP planning^[1]

Clinical summary

Diagnosis, antibiotic management, and timing of cholecystectomy for acute calculous cholecystitis in adults.

References

1.WSES Guidelines for Diagnosis and Treatment of Acute Calculous Cholecystitis (2020 update); Tokyo Guidelines TG18 for Acute Cholecystitis (2020)

Drug

Class

Adult

Paediatric

Notes

Co-amoxiclav (community-acquired, mild)^[1]

Aminopenicillin + beta-lactamase inhibitor

1.2 g IV every 8 h; switch to oral 625 mg TDS once tolerating diet

Per local protocol

First-line for mild community-acquired cholecystitis without severity features; review at 48 h with cultures

Piperacillin-tazobactam^[1]

Beta-lactam + beta-lactamase inhibitor

4.5 g IV every 6–8 h

Per local protocol

Moderate-severe or healthcare-associated cholecystitis; broad gram-positive, gram-negative, anaerobic; renal dose adjustment

Ceftriaxone + metronidazole^[1]

Third-generation cephalosporin + nitroimidazole

Ceftriaxone 1–2 g IV daily + metronidazole 500 mg IV every 8 h

Ceftriaxone 50–80 mg/kg/day; metronidazole 7.5 mg/kg every 8 h

Alternative for mild-moderate community-acquired; oral switch to cefuroxime + metronidazole when improving

Meropenem (severe / ESBL risk)^[1]

Carbapenem

1 g IV every 8 h

20 mg/kg every 8 h

Reserve for severe cholangitis, ESBL coverage, prior multi-resistant organism; renal dose adjustment