From the Guidelines
For acalculous cholecystitis, the best initial antibiotic regimen is Piperacillin/Tazobactam, especially in unstable patients, as recommended by the 2017 WSES and SICG guidelines 1. The choice of antibiotic is crucial in the management of acalculous cholecystitis, and the guidelines provide several options based on the patient's stability.
- In stable patients, alternatives include Amoxicillin/Clavulanate, Ticarcillin/Clavulanate, Ceftriazone + Metranidazole, or Ertapenem, especially if there are risk factors for ESBLs 1.
- In unstable patients, Cefepime + Metranidazole is also a recommended option 1. The initial antibiotic regimen should be chosen based on the patient's clinical condition and risk factors for resistant organisms, with the goal of providing broad-spectrum coverage against gram-negative organisms, enterococci, and anaerobes commonly implicated in acalculous cholecystitis. Treatment should be initiated promptly after diagnosis and blood cultures are obtained, and switched to oral therapy as soon as clinical conditions improve, as stated in the guidelines 1. The management of acalculous cholecystitis also involves supportive care and consideration for percutaneous cholecystostomy or cholecystectomy, particularly if the patient doesn't improve within 24-48 hours of antibiotic initiation.
From the Research
Initial Antibiotics for Acalculous Cholecystitis
- The best initial antibiotics for acalculous cholecystitis are not explicitly stated in the provided studies, but it is mentioned that empirically selected broad-spectrum antibiotic therapy should be prescribed according to the severity of the cholecystitis, an associated history of recent antibiotic therapy, and local bacterial susceptibility patterns 2.
- The choice of antibiotics may depend on the suspected causative organisms, and adjustment to a narrower spectrum antimicrobial agent should be made based on the results of sensitivity testing 2.
- There is limited information on the specific antibiotics used in the treatment of acalculous cholecystitis, but it is noted that antibiotics are not indicated for the conservative management of acute calculous cholecystitis or in patients scheduled for cholecystectomy 3.
Treatment Outcomes
- The overall therapeutic outcomes for patients with acalculous cholecystitis did not differ statistically between those treated with antibiotics alone or percutaneous cholecystostomy, and those treated with cholecystectomy 4.
- The recurrence rate after nonsurgical treatment was significantly lower in patients with acalculous cholecystitis compared to those with acute calculous cholecystitis 4.
- Non-surgical management of acalculous cholecystitis, including antibiotics only or percutaneous cholecystostomy, may be effective in selected patients, with a recurrence rate of 9.8% during a mean follow-up of 5.7 years 5.
Pathophysiological Mechanisms
- Acute acalculous cholecystitis is an inflammation of the gallbladder not associated with the presence of gallstones, and it usually occurs in critically ill patients, but it has also been implicated as a cause of cholecystitis in previously healthy individuals 6.
- Infectious causes comprise the primary etiology of acalculous cholecystitis in previously healthy individuals, and awareness of the implicated pathogens is essential for a more focused examination of the histopathological specimens 6.