Sandbox/intraabdominal

Definitions

From a clinical view, intra-abdominal infections can be classified in:

• Uncomplicated, in which the infectious process involves only a single organ and there is no anatomical disruption
• Complicated, in which the infectious process extends beyond the hollow viscus into the peritoneal space and is associated with abscess formation or peritonitits.

Patients with uncomplicated intra-abdominal infections usually do not need antimicrobial therapy besides perioperative prophylaxis and can be managed with surgery alone (i.e. appendicitis).

A health care-associated infection is a new term that describe patients that have a close contact with health systems, they include community-onset infection and hospital-onset infection. The following table describes the two types of health care-associated infection that would guide the therapeutic regimen.

Community-onset infection	Hospital-onset infection
Includes patients with 1 or more of the following conditions: The presence of an invasive device at time of admission History of MRSA infection or colonization History of surgery, hospitalization, dialysis, or residence in a long-term care facility in the previous 12 months.	Includes patients with positive culture results obtained >48 h after admission. Patients might also have 1 of the conditions described in community-onset infection.

Principles of Therapy for Complicated Intra-abdominal Infection

The following table describes the factors that define a high risk infection, due to an increase chance of treatment failure and a more severe infection.

Clinical factors for high risk patients
Delay in the initial intervention (>24 h)
APACHE II score ≥ 15
Advanced age (>70 years)
Comorbidity and degree of organ dysfunction
Low albumin level
Poor nutrition status
Degree of peritoneal involvement or diffuse peritonitis
Inability to achieve adequate debridement or control of drainage
Presence of malignancy

• All patients should undergo a source control procedure to clear infected foci.
• Patients should undergo rapid fluid resuscitation to restore cardiovascular homeostasis. For patients with septic shock, follow The Surviving Sepsis Campaign guidelines for managing septic shock.
• If the diagnosis of intra-abdominal infection is confirmed or is considered highly likely, antibiotics should be initiated immediately.
• Patients without septic shock should receive antimicrobial therapy in the emergency department.
• For patients with lower-risk with co community-acquired infection, cultures are optional. For higher-risk patients, cultures from the site of infection should be obtained.
• Sensibility testing for Pseudomonas, Proteus, Acinetobacter, Staphylococcus aureus, and Enterobacteriaceae should be done, as this organisms have shown higher resistance rates in recent years.
• Lower-risk patients with community-acquired intra-abdominal infection and a favorable clinical progress do not require modification of therapy.
• If microorganisms with high pathogenic potential are found, susceptibility results should be used to determine antibiotic therapy in high-severity community-acquired or health care-associated infection.
• The recommended duration of therapy is 4-7 days.
• Completion of the antibiotic course with oral forms can be considered if the patient evolves favorably, is able to tolerate an oral diet and if his susceptibility studies do not show resistant microorganisms.

Extra-biliary Complicated Intra-abdomninal Infection

Community-acquired

▸ Click on the following categories to expand treatment regimens.

Children   ▸  Single agent   ▸  Combination Adults - Mild to Moderate   ▸  Single agent   ▸  Combination Adults - Severe   ▸  Single agent   ▸  Combination

Children Single Antibiotic Regimen ▸ Ertapenem 3 months to 12 years 15 mg/kg IV q12h; >13 years 1 g IV q24h OR ▸ Meropenem 60 mg/kg/day IV q8h OR ▸ Imipenem/Cilastatin 60-100 mg/kg/day IV q4-6h OR ▸ Ticarcillin-Clavulanate 200-300 mg/kg/day IV q12h OR ▸ Piperacillin-Tazobactam 200-300 mg/kg/day IV q6-8h Children Combined Antibiotic Regimen ▸ Ceftriaxone 50-70 mg/kg/day IV q12-24h OR ▸ Cefotaxime 150-200 mg/kg/day IV q6-8h OR ▸ Cefepime 100 mg/kg/day IV q12h OR ▸ Ceftazidime 150 mg/kg/day IV q8h PLUS ▸ Metronidazole 30-40 mg/kg/day IV q8h OR ▸ Gentamicin 3-7.5 mg/kg/day IV q2-4h OR ▸ tobramycin 3-7.5 mg/kg/day IV q8-24h PLUS ▸ Metronidazole 30-40 mg/kg/day IV q8h OR ▸ Clindamycin 20-40 mg/kg/day IV q6-8h WITH OR WITHOUT ▸ Ampicillin 200 mg/kg/day IV q8-24h Adults - Mild to Moderate Single Antibiotic Regimen ▸ Cefoxitin 2 g IV q6h OR ▸ Ertapenem 1 g IV q24h OR ▸ Moxifloxacin 400 mg IV q24h OR ▸ Tigecycline 100 mg initial dose, then 50 mg IV q12h OR ▸ Ticarcillin-Clavulanic acid 200 mg/kg/day IV q6h Adults - Mild to Moderate Combined Antibiotic Regimen ▸ Cefazolin 1-2 g IV q8h OR ▸ Cefuroxime 1.5 g IV q8h OR ▸ Ceftriaxone 1-2 g IV q12-24h OR ▸ Cefotaxime 1-2 g IV q6-8h OR ▸ Ciprofloxacin 400 mg IV q12h OR ▸ Levofloxacin 750 mg IV q24h PLUS ▸ Metronidazole 500 mg IV q8-12h or 1.5 g q24h Adults - Severe Single Antibiotic Regimen ▸ Imipenem-Cilastatin 500 g IV q6h or 1 g q8h OR ▸ Meropenem 1 g IV q8h OR ▸ Doripenem 500 g IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h† † For Pseudomonas aeruginosa may be increased to 3.375 g q4h or 4.5 g q6h . Adults - Severe Combined Antibiotic Regimen ▸ Cefepime 2 g IV q8-12h OR ▸ Ceftazidime 2 g IV q8h OR ▸ Ciprofloxacin 400 g IV q12h OR ▸ Levofloxacin 750 mg IV q24h PLUS ▸ Metronidazole 500 mg IV q8-12h or 1.5 g q24h

Health Care-Associated

▸ Click on the following categories to expand treatment regimens.

Multidrug resistant gram-negative bacilli   ▸  Recommended Regimen ESBL-Enterobacteriaceae   ▸  Recommended Regimen Pseudomonas aeruginosa >20% resistant to ceftazidime   ▸  Recommended Regimen MRSA   ▸  Recommended Regimen

Recommended Regimen Carbapenem ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 g IV q6h or 1 g q8h OR ▸ Doripenem 500 g IV q8h Cephalosporin-based ▸ Ceftazidime 200-300 mg/kg/day IV q12h OR ▸ Cefepime 200-300 mg/kg/day IV q12h PLUS ▸ Metronidazole 500 mg IV q8-12h or 1.5 g q24h Penicillin-based ▸ Piperacillin-Tazobactam 3.375 g q4h or 4.5 g q6h Recommended Regimen Carbapenem ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 g IV q6h or 1 g q8h OR ▸ Doripenem 500 g IV q8h Penicillin-based ▸ Piperacillin-Tazobactam 3.375 g IV q6h Recommended Regimen Carbapenem ▸ Meropenem 1 g IV q8h OR | ▸ Imipenem/Cilastatin 500 g IV q6h or 1 g q8h OR ▸ Doripenem 500 g IV q8h Penicillin-based ▸ Piperacillin-Tazobactam 3.375 g IV q6h Recommended Regimen ▸ Vancomycin 1-2 g IV q8h

Biliary Infection

Community-acquired Acute Cholecystitis

▸ Click on the following categories to expand treatment regimens.

Acute Cholecystitis   ▸  Mild-to-moderate   ▸  Severe Special Considerations   ▸  Post Bilio-enteric Anastamosis   ▸  Advanced age   ▸  Immunocompromised

Mild-to-moderate Acute Cholecystitis ▸ Cefazolin 1-2 g IV q8h OR ▸ Cefuroxime 1.5 g IV q8h OR ▸ Ceftriaxone 1-2 g IV q12-24h Severe Acute Cholecystitis ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 g IV q6h or 1 g q8h OR ▸ Doripenem 500 g IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 g IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h PLUS ▸ Metronidazole 500 mg IV q8-12h or 1.5 g q24h Acute cholangitis after bilio-enteric anastamosis ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 g IV q6h or 1 g q8h OR ▸ Doripenem 500 g IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 g IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h PLUS ▸ Metronidazole 500 mg IV q8-12h or 1.5 g q24h

Health Care-Associated Acute Cholecystitis

Biliary infection of any severity   ▸  Recommended Regimen

Biliary Infection of any severity ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 g IV q6h or 1 g q8h OR ▸ Doripenem 500 g IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 g IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h PLUS ▸ Metronidazole 500 mg IV q8-12h or 1.5 g q24h PLUS ▸ Vancomycin 1-2 g IV q8h