Table 14 Clinical pathway for patients with acute appendicitis is illustrated

Clinical signs and symptoms

• Fever

• Abdominal pain

• Abdominal tenderness

Laboratory markers

• Increased white blood cell

• C-reactive protein

• PCT

Imaging

• CT

Diagnosis

Localised abscess

• Percutaneous drainage and antibiotic therapy. Antibiotics and drainage may be the optimal means of treating post-operative localized intra-abdominal abscesses in stable patients when there are no signs of generalized peritonitis.

• Diffuse peritonitis

• Early surgical source control and antibiotic therapy. The inability to control the septic source is associated with an intolerably high mortality rate.

+

Antibiotic therapy

Treatment

In patients with no risk for multidrug-resistant organism

One of the following intravenous antibiotics

Piperacillin/tazobactam 6 g/0.75 g LD then 4 g/0.5 g every 6 h or 16 g/2 g by continuous infusion

Tigecycline 100 mg initial dose, then 50 mg every 12 h (carbapenem sparing strategy)

Meropenem 1 g every 8 h +/− ampicillin 2 g every 6 h (critically ill patients)

Doripenem 500 mg every 8 h +/− ampicillin 2 g every 6 h (critically ill patients)

Imipenem/cilastatin 500 mg every 6 h (critically ill patients)

+/−

In patients at high risk for invasive candidiasis

Fluconazole 800 mg LD then 400 mg every 24 h

In patients with documented beta-lactam allergy, consider the use of antibiotic combinations with Amikacin 15–20 mg/kg every 24 h

In patients with high risk for multidrug-resistant organism

One of the following intravenous antibiotics

Tigecycline 100 mg LD, then 50 mg every 12 h (not active against Pseudomonas aeruginosa)

Eravacycline 1 mg/kg every 12 h (not active against Pseudomonas aeruginosa)

+

Piperacillin/tazobactam 4.5 every 6 h

or

In critically ill patients

one of the following intravenous antibiotics

Meropenem 1 g every 8 h

Doripenem 500 mg every 8 h

Imipenem/cilastatin 500 mg every 6 h

+

One of the following intravenous antibiotics

Vancomycin 25–30 mg/kg LD then 15–20 mg/kg/dose every 8 h

Teicoplanin 12 mg/kg every 12 h 3 LDs then 12 mg/kg every 24 h

+/−

In patients with high risk for invasive candidiasis

In stable patients

Fluconazole 800 mg LD then 400 mg every 24 h

In unstable patients

one of the following antifungal agents

Caspofungin 70 mg LD, then 50 mg daily

Anidulafungin 200 mg LD, then 100 mg daily

Micafungin 100 mg daily

Amphotericin B Liposomal 3 mg/kg daily (renal toxicity risk)

In patients with suspected or proven infection with MDR (non-metallo-beta-lactamase-producing) Pseudomonas aeruginosa, consider the use of antibiotic combinations with Ceftolozane/tazobactam.

In patients with suspected or proven infection with carbapenemase-producing Klebsiella pneumoniae and MDR (non-metallo-beta-lactamase-producing) Pseudomonas aeruginosa, consider the use of antibiotic combinations with Ceftazidime/Avibactam.

In patients with suspected or proven infection with vancomycin-resistant enterococci (VRE) including patients with previous enterococcal infection or colonization, immunocompromised patients, patients with long ICU stay, or recent Vancomycin exposure

One of the following intravenous antibiotics

Tigecycline 100 mg LD, then 50 mg every 12 h

Linezolid 600 mg every 12 h

In patients with documented beta-lactam allergy, consider the use of antibiotic combinations with Amikacin 15–20 mg/kg daily.

Antibiotic therapy