Cholecystitis is inflammation of the gallbladder that occurs most commonly because of an obstruction of the cystic duct by gallstones arising from the gallbladder (cholelithiasis). Uncomplicated cholecystitis has an excellent prognosis; the development of complications such as perforation or gangrene renders the prognosis less favorable.
The most common presenting symptom of acute cholecystitis is upper abdominal pain. The following characteristics may be reported:
Patients with acalculous cholecystitis may present with fever and sepsis alone, without history or physical examination, findings consistent with acute cholecystitis.
Cholecystitis may present differently in special populations, as follows:
The physical examination may reveal the following:
The absence of physical findings does not rule out the diagnosis of cholecystitis.
See Presentation for more detail.
Laboratory tests are not always reliable, but the following findings may be diagnostically useful:
Diagnostic imaging modalities that may be considered include the following:
The American College of Radiology (ACR) makes the following imaging recommendations:
See Workup for more detail.
Treatment of cholecystitis depends on the severity of the condition and the presence or absence of complications.
In acute cholecystitis, the initial treatment includes bowel rest, IV hydration, correction of electrolyte abnormalities, analgesia, and IV antibiotics. Options include the following:
In cases of uncomplicated cholecystitis, outpatient treatment may be appropriate. The following medications may be useful in this setting:
Surgical and interventional procedures used to treat cholecystitis include the following:
See Treatment and Medication for more detail.
Cholecystitis is defined as inflammation of the gallbladder that occurs most commonly because of an obstruction of the cystic duct from cholelithiasis. Ninety percent of cases involve stones in the gallbladder (ie, calculous cholecystitis), with the other 10% of cases representing acalculous cholecystitis.
Risk factors for cholecystitis mirror those for cholelithiasis and include increasing age, female sex, certain ethnic groups, obesity or rapid weight loss, drugs, and pregnancy. Although bile cultures are positive for bacteria in 50-75% of cases, bacterial proliferation may be a result of cholecystitis and not the precipitating factor.
Acalculous cholecystitis is related to conditions associated with biliary stasis, including debilitation, major surgery, severe trauma, sepsis, long-term total parenteral nutrition (TPN), and prolonged fasting. Other causes of acalculous cholecystitis include cardiac events; sickle cell disease; Salmonella infections; diabetes mellitus; and cytomegalovirus, cryptosporidiosis, or microsporidiosis infections in patients with AIDS. (See Etiology.) For more information, see the Medscape Reference article Acalculous Cholecystopathy.
Uncomplicated cholecystitis has an excellent prognosis, with a very low mortality rate. Once complications such as perforation/gangrene develop, the prognosis becomes less favorable. Some 25-30% of patients either require surgery or develop some complication. (See Prognosis.)
The most common presenting symptom of acute cholecystitis is upper abdominal pain. The physical examination may reveal fever, tachycardia, and tenderness in the RUQ or epigastric region, often with guarding or rebound. However, the absence of physical findings does not rule out the diagnosis of cholecystitis. (See Clinical Presentation.)
Delays in making the diagnosis of acute cholecystitis result in a higher incidence of morbidity and mortality. This is especially true for ICU patients who develop acalculous cholecystitis. The diagnosis should be considered and investigated promptly in order to prevent poor outcomes. (See Diagnosis.)
Initial treatment of acute cholecystitis includes bowel rest, intravenous hydration, correction of electrolyte abnormalities, analgesia, and intravenous antibiotics. For mild cases of acute cholecystitis, antibiotic therapy with a single broad-spectrum antibiotic is adequate. Outpatient treatment may be appropriate for uncomplicated cholecystitis. If surgical treatment is indicated, laparoscopic cholecystectomy represents the standard of care. (See Treatment and Management.)
Patients diagnosed with cholecystitis must be educated regarding causes of their disease, complications if left untreated, and medical/surgical options to treat cholecystitis. For patient education information, see the Liver, Gallbladder, and Pancreas Center, as well as Gallstones and Pancreatitis.
For further clinical information, see the Medscape Reference topic Cholecystitis and Biliary Colic.
Ninety percent of cases of cholecystitis involve stones in the gallbladder (ie, calculous cholecystitis), with the other 10% of cases representing acalculous cholecystitis.
Acute calculous cholecystitis is caused by obstruction of the cystic duct, leading to distention of the gallbladder. As the gallbladder becomes distended, blood flow and lymphatic drainage are compromised, leading to mucosal ischemia and necrosis.
Although the exact mechanism of acalculous cholecystitis is unclear, several theories exist. Injury may be the result of retained concentrated bile, an extremely noxious substance. In the presence of prolonged fasting, the gallbladder never receives a cholecystokinin (CCK) stimulus to empty; thus, the concentrated bile remains stagnant in the lumen.[2, 3]
A study by Cullen et al demonstrated the ability of endotoxin to cause necrosis, hemorrhage, areas of fibrin deposition, and extensive mucosal loss, consistent with an acute ischemic insult. Endotoxin also abolished the contractile response to CCK, leading to gallbladder stasis.
Risk factors for calculous cholecystitis mirror those for cholelithiasis and include the following:
Acalculous cholecystitis is related to conditions associated with biliary stasis, and include the following:
Other causes of acalculous cholecystitis include the following:
Patients who are immunocompromised are at an increased risk of developing cholecystitis from a number of different infectious sources. Idiopathic cases exist.
An estimated 10-20% of Americans have gallstones, and as many as one third of these people develop acute cholecystitis. Cholecystectomy for either recurrent biliary colic or acute cholecystitis is the most common major surgical procedure performed by general surgeons, resulting in approximately 500,000 operations annually.
The incidence of cholecystitis increases with age. The physiologic explanation for the increasing incidence of gallstone disease in the elderly population is unclear. The increased incidence in elderly men has been linked to changing androgen-to-estrogen ratios.
Go to Pediatric Cholecystitis for more complete information on this topic.
Gallstones are 2-3 times more frequent in females than in males, resulting in a higher incidence of calculous cholecystitis in females. Elevated progesterone levels during pregnancy may cause biliary stasis, resulting in higher rates of gallbladder disease in pregnant females. Acalculous cholecystitis is observed more often in elderly men.
Cholelithiasis, the major risk factor for cholecystitis, has an increased prevalence in people of Scandinavian descent, Pima Indians, and Hispanic populations, whereas cholelithiasis is less common among individuals from sub-Saharan Africa and Asia.[6, 7] In the United States, white people have a higher prevalence than black people.
Uncomplicated cholecystitis has an excellent prognosis, with a very low mortality. Most patients with acute cholecystitis have a complete remission within 1-4 days. However, 25-30% of patients either require surgery or develop some complication.
Once complications such as perforation/gangrene develop, the prognosis becomes less favorable. Perforation occurs in 10-15% of cases. Patients with acalculous cholecystitis have a mortality ranging from 10-50%, which far exceeds the expected 4% mortality observed in patients with calculous cholecystitis. In patients who are critically ill with acalculous cholecystitis and perforation or gangrene, mortality can be as high as 50-60%.
The severity of acute cholecystitis also has an impact on the risk of iatrogenic bile duct injury during cholecystectomy. Tornqvist et al reported a doubling of the risk for sustaining a biliary lesion in patients with ongoing acute cholecystitis compared to those without acute cholecystitis. Patients with Tokyo grade II (moderate) acute cholecystitis and those with Tokyo grade III (severe) cholecystitis had, respectively, over double and more than eight times the risk of bile duct injury compared to those without acute cholecystitis. The risk of biliary injury was reduced by 52% with intention to use intraoperative cholangiography.
The most common presenting symptom of acute cholecystitis is upper abdominal pain. Signs of peritoneal irritation may be present, and in some patients, the pain may radiate to the right shoulder or scapula. Frequently, the pain begins in the epigastric region and then localizes to the right upper quadrant (RUQ). Although the pain may initially be described as colicky, it becomes constant in virtually all cases. Nausea and vomiting are generally present, and patients may report fever.
Most patients with acute cholecystitis describe a history of biliary pain. Some patients may have documented gallstones. Acalculous biliary colic also occurs, most commonly in young to middle-aged females. The presentation is almost identical to calculous biliary colic with the exception of reference range laboratory values and no findings of cholelithiasis on ultrasound. Cholecystitis is differentiated from biliary colic by the persistence of constant severe pain for more than 6 hours.
Patients with acalculous cholecystitis may present similarly to patients with calculous cholecystitis, but acalculous cholecystitis frequently occurs suddenly in severely ill patients without a prior history of biliary colic. Often, patients with acalculous cholecystitis may present with fever and sepsis alone, without history or physical examination findings consistent with acute cholecystitis.
Elderly patients (especially patients with diabetes) may present with vague symptoms and without many key historical and physical findings. Pain and fever may be absent, and localized tenderness may be the only presenting sign. Elderly patients may also progress to complicated cholecystitis rapidly and without warning.
The pediatric population may also present without many of the classic findings. Children who are at a higher risk for developing cholecystitis include patients with sickle cell disease, seriously ill children, those on prolonged TPN, those with hemolytic conditions, and those with congenital and biliary anomalies. For more information, see the Medscape Reference article Pediatric Cholecystitis.
Bacterial proliferation within the obstructed gallbladder results in empyema of the organ. Patients with empyema may have a toxic reaction and may have more marked fever and leukocytosis.[10, 11] The presence of empyema frequently requires conversion from laparoscopic to open cholecystectomy.
In rare instances, a large gallstone may erode through the gallbladder wall into an adjacent viscus, usually the duodenum. Subsequently, the stone may become impacted in the terminal ileum or in the duodenal bulb and/or pylorus, causing gallstone ileus.
Emphysematous cholecystitis occurs in approximately 1% of cases and is noted by the presence of gas in the gallbladder wall from the invasion of gas-producing organisms, such as Escherichia coli, Clostridia perfringens, and Klebsiella species. This complication is more common in patients with diabetes, has a male predominance, and is acalculous in 28% of cases. Because of a high incidence of gangrene and perforation, emergency cholecystectomy is recommended. Perforation occurs in up to 15% of patients.[11, 13] For more information, see the Medscape Reference article Emphysematous Cholecystitis.
Other complications include sepsis and pancreatitis.
The physical examination may reveal fever, tachycardia, and tenderness in the RUQ or the epigastric region, often with guarding or rebound. The Murphy sign, which is specific but not sensitive for cholecystitis, is described as tenderness and an inspiratory pause elicited during palpation of the RUQ. A palpable gallbladder or fullness of the RUQ is present in 30-40% of cases. Jaundice may be noted in approximately 15% of patients.
The absence of physical findings does not rule out the diagnosis of cholecystitis. Many patients present with diffuse epigastric pain without localization to the RUQ. Patients with chronic cholecystitis frequently do not have a palpable RUQ mass secondary to fibrosis involving the gallbladder.
Elderly patients and patients with diabetes frequently have atypical presentations, including absence of fever and localized tenderness with only vague symptoms.
The workup for cholecystitis may include laboratory tests (though these are not always reliable), radiography, ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), hepatobiliary scintigraphy (HBS), and endoscopy.
Although laboratory criteria are not reliable in identifying all patients with cholecystitis, the following findings may be useful in arriving at the diagnosis:
A retrospective study by Singer, aimed at determining a set of clinical and laboratory parameters that could be used to predict the outcome of hepatobiliary scintigraphy (HBS) in patients with suspected acute cholecystitis, found that of 40 patients with pathologically confirmed acute cholecystitis, 36 (90%) did not have fever at the time of presentation and 16 (40%) did not have leukocytosis. The study also found that no combination of laboratory or clinical values was useful in identifying patients at high risk for a positive HBS finding.
The 2010 American College of Radiology (ACR) Appropriateness Criteria offer the following imaging recommendations :
Gallstones may be visualized on noncontrast radiography in 10-15% of cases. This finding only indicates cholelithiasis, with or without active cholecystitis.
Subdiaphragmatic free air cannot originate in the biliary tract, and if present, it indicates another disease process. Gas limited to the gallbladder wall or lumen represents emphysematous cholecystitis, usually because of gas-forming bacteria, such as Escherichia coli and clostridial and anaerobic streptococci species. Emphysematous cholecystitis is associated with increased mortality and occurs most commonly in males with diabetes and with acalculous cholecystitis.
Go to Emphysematous Cholecystitis for more complete information on this topic.
A diffusely calcified gallbladder (ie, porcelainized) most commonly is associated with carcinoma, although 2 studies have found no association between partial calcification of the gallbladder and carcinoma.[19, 20]
Other findings may include renal calculi, intestinal obstruction, or pneumonia.
Go to Imaging in Acute Cholecystitis and Imaging in Acalculous Cholecystitis for more complete information on these topics.
Ultrasonography is 90-95% sensitive for cholecystitis and is 78-80% specific. It provides greater than 95% sensitivity and specificity for the diagnosis of gallstones more than 2 mm in diameter. Studies indicate that emergency clinicians require minimal training in order to use right upper quadrant ultrasonography in their practice.[21, 22, 23, 24, 25, 26]
Ultrasonographic findings that are suggestive of acute cholecystitis include the following: pericholecystic fluid, gallbladder wall thickening greater than 4 mm, and sonographic Murphy sign. The presence of gallstones also helps to confirm the diagnosis.
Ultrasonography is performed best following a fast of at least 8 hours because gallstones are visualized best in a distended bile-filled gallbladder.
Contrast-enhanced ultrasonography (CEUS) with the agent perflubutane (Sonazoid) shows promise for its use in the diagnosis of gangrenous cholecystitis. In a study comprising 27 patients with acute cholecystitis who underwent preoperative CEUS, 15 patients had a final diagnosis of gangrenous cholecystitis and 12 patients had uncomplicated cholecystitis, all confirmed via histologic examination. Of the 15 patients diagnosed with gangrenous cholecystitis, CEUS detected perfusion defects in 10 patients (66.7% sensitivity, 100% specificity; 100% positive predictive value [PPV] and 70.6% negative predictive value [NPV]). Review of the movie clips of the CEUS raised the sensitivity to 73.3% and the NPV to 75%. Interobserver agreement was good (κ coefficient = 0.64).
Disadvantages of ultrasonography include the fact that this imaging modality is operator and patient dependent, it is unable to image the cystic duct, and it has a decreased sensitivity for common bile duct stones. In addition, in the setting of concomittant acute pancreatitis, ultrasonographic findings alone are not adequate to accurately identify acute cholecystitis.
Go to Imaging in Acute Cholecystitis and Imaging in Acalculous Cholecystitis for more complete information on these topics.
The sensitivity and specificity of computed tomography (CT) scanning and magnetic resonance imaging (MRI) in predicting acute cholecystitis have been reported to be greater than 95%. Spiral CT scan and MRI (unlike endoscopic retrograde cholangiopancreatography [ERCP]) have the advantage of being noninvasive, but they have no therapeutic potential and are most appropriate in cases where stones are unlikely.
Findings suggestive of cholecystitis include wall thickening (>4 mm), pericholecystic fluid, subserosal edema (in the absence of ascites), intramural gas, and sloughed mucosa.
Diffusion-weighted (DW) magnetic resonance imaging (MRI) shows potential for differentiating between acute and chronic cholecystits. In a study comprising 83 patients with abdominal pain, Wang et al noted that increased signal on high b-value images were highly sensitive and moderately specific for acute cholecystitis.
CT scanning and MRI are also useful for viewing surrounding structures if the diagnosis is uncertain.
Go to Imaging in Acute Cholecystitis and Imaging in Acalculous Cholecystitis for more complete information on these topics.
HBS has been found to be up to 95% accurate in diagnosing acute cholecystitis. The reported sensitivities and specificities of biliary scintigraphy are in the range of 90-100% and 85-95%. (See the following 2 images.)
Cholecystitis. Normal finding on hepatoiminodiacetic acid (HIDA) scan.
Cholecystitis. Abnormal finding on hepatoiminodiacetic acid (HIDA) scan.
In a typical study, the gallbladder, common bile duct, and small bowel fill within 30-45 minutes. If the gallbladder is not visualized, intravenous morphine administration can improve the accuracy of HBS by increasing resistance to flow through the sphincter of Oddi, resulting in filling of the gallbladder if the cystic duct is patent. The addition of morphine also reduces the number of false-positive scan results observed in patients who are critically ill and immobilized with viscous bile.
ERCP may be useful for visualizing the anatomy in patients at high risk for gallstones if signs of common bile duct obstruction are present. A study performed by Sahai et al found that ERCP was preferred over endoscopic ultrasonography and intraoperative cholangiography for patients at high risk for common bile duct stones undergoing laparoscopic cholecystectomy.
Disadvantages of ERCP include the need for a skilled operator, high cost, and complications such as pancreatitis, which occurs in 3-5% of cases.
Edema and venous congestion are early acute changes. Acute cholecystitis is usually superimposed on a histologic picture of chronic cholecystitis. Specific findings include fibrosis, flattening of the mucosa, and chronic inflammatory cells. Mucosal herniations known as Rokitansky-Aschoff sinuses are related to increased hydrostatic pressure and are present in 56% of cases. Focal necrosis and an influx of neutrophils may also be present. Advanced cases may show gangrene or perforation.
Treatment of cholecystitis depends on the severity of the condition and the presence or absence of complications. Uncomplicated cases can often be treated on an outpatient basis; complicated cases may necessitate a surgical approach. In patients who are unstable, percutaneous transhepatic cholecystostomy drainage may be appropriate. Antibiotics may be given to manage infection. Definitive therapy involves cholecystectomy or placement of a drainage device; therefore, consultation with a surgeon is warranted. Consultation with a gastroenterologist for consideration of endoscopic retrograde cholangiopancreatography (ERCP) may also be appropriate if concern exists of choledocholithiasis.
Patients admitted for cholecystitis should receive nothing by mouth because of expectant surgery. However, in uncomplicated cholecystitis, a liquid or low-fat diet may be appropriate until the time of surgery.
For more information, see the Medscape Reference article Imaging in Cholecystitis and Biliary Colic.
In acute cholecystitis, the initial treatment includes bowel rest, intravenous hydration, correction of electrolyte abnormalities, analgesia, and intravenous antibiotics. For mild cases of acute cholecystitis, antibiotic therapy with a single broad-spectrum antibiotic is adequate. Some options include the following:
Outpatient treatment may be appropriate for cases of uncomplicated cholecystitis. If a patient can be treated as an outpatient, discharge with antibiotics, appropriate analgesics, and definitive follow-up care. Criteria for outpatient treatment include the following:
The following medications may be appropriate in this setting:
Laparoscopic cholecystectomy is the standard of care for the surgical treatment of cholecystitis. Studies have indicated that early laparoscopic cholecystectomy resulted in shorter total hospital stays with no significant difference in conversion rates or complications.[32, 33, 34, 35] Zafar et al reported that the best outcomes and lowest costs were achieved when laparoscopic cholecystectomy was performed within 2 days of presentation of acute cholecystitis.
The ACR 2010 criteria state that laparoscopic cholecystectomy is the primary mode of treatment for acute cholecystitis.
The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) issued guidelines for the clinical application of laparoscopic biliary tract surgery in 2010. The guidelines include detailed recommendations for making the decision to operate, performing the procedure, and managing postoperative care, with the patient's safety always the primary consideration. Recommendations are as follows:
Wilson et al used decision tree analytic modeling to compare the cost-effectiveness and quality-adjusted life years (QALYs) of early laparoscopic cholecystectomy (ELC) and delayed laparoscopic cholecystectomy (DLC) and found that, on average, ELC is less expensive and results in better quality of life (+0.05 QALYs per patient) than DLC.[38, 39]
Early operation within 72 hours of admission has both medical and socioeconomic benefits and is the preferred approach for patients treated by surgeons with adequate experience in laparoscopic cholecystectomy. Immediate cholecystectomy or cholecystotomy is usually reserved for complicated cases in which the patient has gangrene or perforation.
One study suggests that when CT scanning is performed as long as 72 hours prior to surgery, it may better detect acute gangrenous cholecystitis. Acute gangrenous cholecystitis was significantly correlated with perfusion defect of the gallbladder wall and pericholecystic stranding, which can be better observed by CT scanning compared with ultrasonography.
Single-incision laparoscopic cholecystectomy appears to be safe and effective for acute cholecystitis.[35, 40] Early surgical intervention potentially reduces the risk of laparotomy conversion. Note that single-incision laparoscopic cholecystectomy may be associated with an 8% rate of incisional hernia rate, with age (≥50 years) and body mass index (BMI) (≥30 kg/m2) as independent predictive factors.
For elective laparoscopic cholecystectomy, the rate of conversion from a laparoscopic procedure to an open surgical procedure is approximately 5%. The conversion rate for emergency cholecystectomy where perforation or gangrene is present may be as high as 30%.
Although laparoscopic cholecystectomy performed in pregnant women is considered safest during the second trimester, it has been performed successfully during all trimesters.
Contraindications to laparoscopic cholecystectomy include the following:
The 2010 SAGES guideline adds to these contraindications septic shock from cholangitis, acute pancreatitis, lack of equipment, lack of surgical expertise, and previous abdominal surgery that impedes the procedure.
For patients at high surgical risk, placement of a sonographically guided, percutaneous, transhepatic cholecystostomy drainage tube coupled with the administration of antibiotics may provide definitive therapy. Results of studies suggest that most patients with acute acalculous cholecystitis can be treated with percutaneous drainage alone,[44, 45] but the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) guideline describes radiographically guided percutaneous cholecystostomy as a temporizing measure until the patient can undergo cholecystectomy.
Endoscopy may be used for therapeutic purposes, as well as for diagnosis.
Endoscopic retrograde cholangiopancreatography (ERCP) allows visualization of the anatomy and can provide therapy by removing stones from the common bile duct.
Studies indicate that this procedure may be safe as an initial, interim, or definitive treatment of patients with severe acute cholecystitis who are at high operative risk for immediate cholecystectomy.
Endoscopic ultrasonographic (EUS)–guided biliary drainage procedures continue to evolve; they may be used as primary and/or second intervention, such as in the following clinical scenarios :
Mutignani et al, in a study of the efficacy of endoscopic gallbladder drainage as a treatment for acute cholecystitis in 35 patients with the condition and with no residual common bile duct obstruction, found that endoscopic gallbladder drainage was technically successful in 29 patients and, after a median period of 3 days, clinically successful in 24 of them.
Four patients died within 3 days after the procedure as a result of septic complications, while a fifth patient accidentally removed a nasocholecystic drain 24 hours after the operation. At follow-up (on 21 patients, after a median period of 17 months), the investigators found that 4 patients had suffered a relapse of either acute cholecystitis (2 patients) or biliary pain (2 patients). Mutignani et al concluded that endoscopic gallbladder drainage appears to be an effective, but temporary, means of resolving acute cholecystitis.
Studies indicate that EUS-guided transmural stenting for gallbladder drainage is feasible, safe, and effective, with particularly high technical and clinical success rates with the use of plastic stents and self-expandable metal stents (SEMSs). Lumen-apposing metal stents (LAMSs) show promise for having high potentials in efficacy and safety.
The goals of pharmacotherapy are to reduce morbidity and to prevent complications. Agents used in patients with cholecystitis include antiemetics, analgesics, and antibiotics.
Clinical Context: Promethazine is used for symptomatic treatment of nausea in vestibular dysfunction. It is an antidopaminergic agent effective in treating emesis. It blocks postsynaptic mesolimbic dopaminergic receptors in the brain and reduces stimuli to the brainstem reticular system.
Clinical Context: Prochlorperazine may relieve nausea and vomiting by blocking postsynaptic mesolimbic dopamine receptors through anticholinergic effects and depressing the reticular activating system. In addition to antiemetic effects, it has the advantage of augmenting hypoxic ventilatory response, acting as a respiratory stimulant at high altitude.
Patients with cholecystitis frequently experience nausea and vomiting. Antiemetics can help make the patient more comfortable and can prevent fluid and electrolyte abnormalities.
Clinical Context: Meperidine is the drug of choice for pain control. It is an analgesic with multiple actions similar to those of morphine. It may produce less constipation, smooth muscle spasm, and depression of cough reflex than similar analgesic doses of morphine.
Clinical Context: This drug combination is indicated for moderate to severe pain. Each tab/cap contains 5 mg hydrocodone and 500 mg acetaminophen.
Clinical Context: This drug combination is indicated for relief of moderate to severe pain. Each tab/cap contains 5 mg oxycodone and 325 mg acetaminophen.
Pain is a prominent feature of cholecystitis. The classic teaching is that morphine is not the agent of choice because of the possibility of increasing tone at the sphincter of Oddi. Meperidine has been shown to provide adequate analgesia without affecting the sphincter of Oddi and, therefore, is the drug of choice.
Clinical Context: Ciprofloxacin is a fluoroquinolone that inhibits bacterial DNA synthesis and, consequently, growth, by inhibiting DNA gyrase and topoisomerases, which are required for replication, transcription, and translation of genetic material. Quinolones have a broad activity against gram-positive and gram-negative aerobic organisms but no activity against anaerobes. Continue treatment for at least 2 days (7-14 days is typical) after signs and symptoms have disappeared.
Clinical Context: Meropenem is a bactericidal broad-spectrum carbapenem antibiotic that inhibits cell wall synthesis. It is effective against most gram-positive and gram-negative bacteria. It has slightly increased activity against gram-negatives and slightly decreased activity against staphylococci and streptococci compared to imipenem.
Clinical Context: This combination is used to treat multiple-organism infections in which other agents do not have wide spectrum coverage or are contraindicated because of potential for toxicity.
Clinical Context: This combination is an antipseudomonal penicillin plus a beta-lactamase inhibitor. It inhibits biosynthesis of cell wall mucopeptide and is effective during the stage of active multiplication.
Clinical Context: This drug combination is a beta-lactamase inhibitor with ampicillin. It covers epidermal and enteric flora and anaerobes. It is not ideal for nosocomial pathogens.
Clinical Context: Metronidazole is an imidazole ring-based antibiotic that is active against various anaerobic bacteria and protozoa. It is used in combination with other antimicrobial agents (except in Clostridium difficile enterocolitis).
Clinical Context: Levofloxacin is a fluoroquinolone that is used for pseudomonal infections and infections due to multidrug-resistant gram-negative organisms. Prophylactic antibiotic coverage with levofloxacin (Levaquin, 500 mg PO qd) and metronidazole (500 mg PO bid) provides coverage against the most common organisms in cases of uncomplicated cholecystitis.
Clinical Context: Aztreonam is a monobactam, not a beta-lactam, antibiotic that inhibits cell wall synthesis during bacterial growth. It is active against gram-negative bacilli but has very limited gram-positive activity and is not useful for anaerobes. It lacks cross-sensitivity with beta-lactam antibiotics. Aztreonam may be used in patients allergic to penicillins or cephalosporins and is an alternative to life-threatening cases of cholecystitis.
Clinical Context: Ceftriaxone is a third-generation cephalosporin with broad-spectrum, gram-negative activity; it has lower efficacy against gram-positive organisms and higher efficacy against resistant organisms. Its bactericidal activity results from inhibiting cell wall synthesis by binding to one or more penicillin-binding proteins. It exerts an antimicrobial effect by interfering with the synthesis of peptidoglycan, a major structural component of bacterial cell walls. Bacteria eventually lyse as a result of the ongoing activity of cell wall autolytic enzymes, while cell wall assembly is arrested.
Clinical Context: Cefotaxime is a third-generation cephalosporin with a broad gram-negative spectrum, lower efficacy against gram-positive organisms, and higher efficacy against resistant organisms.
Clinical Context: Ceftazidime is a third-generation cephalosporin with broad-spectrum, gram-negative activity, including against pseudomonas; it has lower efficacy against gram-positive organisms and higher efficacy against resistant organisms. It arrests bacterial growth by binding to one or more penicillin-binding proteins, which, in turn, inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell wall synthesis, thus inhibiting cell wall biosynthesis.
Treatment of cholecystitis with antibiotics should provide coverage against the most common organisms, including Escherichia coli and Bacteroides fragilis, as well as Klebsiella,Pseudomonas, and Enterococcus species. Current Sanford guide recommendations for the treatment of cholecystitis include ampicillin/sulbactam or piperacillin/tazobactam for non–life-threatening cases of cholecystitis. In life-threatening cases, Sanford recommends imipenem/cilastatin or meropenem. Alternatives include metronidazole plus a third-generation cephalosporin, ciprofloxacin, or aztreonam.