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 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 the proper [antibiotics]] in the emergency department.
• Only cultures from the site of infection should be obtained from higher-risk patients, for patients with lower-risk community-acquired infection, cultures are optional.
• 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 which show 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 presentations 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-abdominal 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 15 mg/kg IV q12h (max: 1g/day) (for 3 mo - 12 yrs old) ▸ Ertapenem 1 g IV q24h (for >13 yrs old) OR ▸ Meropenem 60 mg/kg/day IV divided q8h OR ▸ Imipenem/Cilastatin 60-100 mg/kg/day IV divided q6h OR ▸ Ticarcillin-Clavulanate 200-300 mg/kg/day IV divided q4-6h (Ticarcillin component) OR ▸ Piperacillin-Tazobactam 200-300 mg/kg/day IV divided q6-8h (Piperacillin component) Children Combined Antibiotic Regimen 1 ▸ Ceftriaxone 50-75 mg/kg/day IV divided q12-24h OR ▸ Cefotaxime 150-200 mg/kg/day IV divided q6-8h OR ▸ Cefepime 100 mg/kg/day IV divided q12h OR ▸ Ceftazidime 150 mg/kg/day IV divided q8h PLUS ▸ Metronidazole 30-40 mg/kg/day IV divided q8h Combined Antibiotic Regimen 2 ▸ Gentamicin† 3-7.5 mg/kg/day IV divided q2-4h OR ▸ Tobramycin† 3-7.5 mg/kg/day IV divided q8-24h PLUS ▸ Metronidazole 30-40 mg/kg/day IV divided q8h OR ▸ Clindamycin 20-40 mg/kg/day IV divided q6-8h WITH OR WITHOUT ▸ Ampicillin 200 mg/kg/day IV divided q6h † Antibiotic serum concentrations and renal function should be monitored 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 divided 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 ▸ Metronidazole 1.5 g IV 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 dose 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 ▸ Metronidazole 1.5 g IV q24h

Health Care-Associated

▸ Click on the following categories to expand treatment regimens.

▸  Gram-Negative Bacilli (<20% multidrug resistance)   ▸  ESBL-Enterobacteriaceae   ▸  P. aeruginosa (>20% resistant to ceftazidime)   ▸  Methicillin-resistant S. aureus   ▸  Candida spp

Gram-Negative Bacilli (<20% multidrug resistance) 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 ▸ Metronidazole 1.5 g IV q24h Penicillin-based ▸ Piperacillin-Tazobactam 3.375 g q4h or 4.5 g q6h ESBL-Enterobacteriaceae† 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 Aminoglycosides ▸ Amikacin¶ 15–20 mg/kg q24 h OR ▸ Gentamicin¶ 5-7 mg/kg q24 h OR ▸ Tobramycin¶ 5-7 mg/kg q24 h † ESBL: extended-spectrum β-lactamase ¶ Adjust dosage based on serum concentrations P. aeruginosa (>20% resistant to ceftazidime) 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 Aminoglycosides ▸ Amikacin¶ 15–20 mg/kg q24 h OR ▸ Gentamicin¶ 5-7 mg/kg q24 h OR ▸ Tobramycin¶ 5-7 mg/kg q24 h ¶ Adjust dosage based on serum concentrations Methicillin-resistant S. aureus ▸ Vancomycin 15–20 mg/kg IV q8-12h Candida spp Candida albicans ▸ Fluconazole 50-200 mg PO/IV q24h Fluconazole-resistant Candida spp ▸ Caspofungin 70 mg IV once, then 50 mg IV q24h OR ▸ Micafungin 100 mg IV q24h OR ▸ Anidulafungin 200 mg IV once, then 100 mg IV q24h

Biliary Infection

Community-acquired Acute Cholecystitis

▸ Click on the following categories to expand treatment regimens.

Acute Cholecystitis   ▸  Mild-to-moderate   ▸  Severe Special Considerations   ▸  Acute Cholangitis after Bilio-enteric Anastomosis   ▸  Acute Cholecystitis in Advanced age   ▸  Acute Cholecystitis in 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 mg IV q6h or 1 g q8h OR ▸ Doripenem 500 mg IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 mg IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h PLUS ▸ Metronidazole 500 mg IV q8-12h OR ▸ Metronidazole 1.5 g IV q24h Acute Cholangitis after Bilio-enteric Anastomosis ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 mg IV q6h or 1 g q8h OR ▸ Doripenem 500 mg IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 mg IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h PLUS ▸ Metronidazole 500 mg IV q8-12h OR ▸ Metronidazole 1.5 g IV q24h Acute Cholecystitis in Advanced Age ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 mg IV q6h or 1 g q8h OR ▸ Doripenem 500 mg IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 mg IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h PLUS ▸ Metronidazole 500 mg IV q8-12h OR ▸ Metronidazole 1.5 g IV q24h Acute Cholecystitis in Immunocompromised ▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 mg IV q6h or 1 g q8h OR ▸ Doripenem 500 mg IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 mg IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h PLUS ▸ Metronidazole 500 mg IV q8-12h OR ▸ Metronidazole 1.5 g IV q24h

Health Care-Associated Biliary Infection

Biliary Infection of any severity
▸ Meropenem 1 g IV q8h OR ▸ Imipenem/Cilastatin 500 mg IV q6h or 1 g q8h OR ▸ Doripenem 500 mg IV q8h OR ▸ Piperacillin-Tazobactam 3.375 g IV q6h OR ▸ Ciprofloxacin 400 mg IV q12h OR ▸ Levofloxacin 750 mg IV q24h OR ▸ Cefepime 2 g IV q8-12h
PLUS
▸ Metronidazole 500 mg IV q8-12h OR ▸ Metronidazole 1.5 g IV q24h
PLUS
▸ Vancomycin 15–20 mg/kg IV q8-12h