Case 085: Intra-Abdominal Infections

PATIENT PRESENTATION

Chief Complaint

“I have that pain in my abdomen again”

History of Present Illness

A patient with diffuse abdominal pain and fever in the setting of known alcohol-induced liver cirrhosis with ascites presents to the emergency department. The patient’s presentation is consistent with spontaneous bacterial peritonitis.

Link to EMR

Student Work-Up

TARGETED QUESTIONS

1. What characteristics of the patient’s case are consistent with SBP?

   Hint: See Clinical Presentation and Diagnosis in PPP

2. How does the management of patients with primary peritonitis differ from secondary peritonitis?

   Hint: See Epidemiology and Etiology in PPP

3. What are the most likely pathogens given this patient’s history and which empirical antimicrobial agent would you start and why?

   Hint: See Pathophysiology, Prevention and Treatment in PPP

4. When do most patients show clinical improvement after antimicrobial agents are started for intra-abdominal infections and what changes in the management should be considered in patients not responding to initial treatment?

   Hint: See Prevention and Treatment in PPP

5. In what clinical situations would a treatment duration of 4-7 days be inadequate?

   Hint: Prevention and Treatment in PPP

FOLLOW-UP

What is a common cause of early death in patients with SBP and how can it be prevented?

Hint: Prevention and Treatment in PPP

CASE SUMMARY

Global Perspective

Gram-negative enteric organisms are the most common causes of SBP in cirrhotic patients, which is why empiric therapy with a third-generation cephalosporin (i.e., ceftriaxone, cefotaxime) is warranted in most cases. Treatment decisions for SBP have been complicated in recent years due to increases in the global incidence of gram-positive organisms including Staphylococcus aureus, Enterococcus faecalis, and Enterococcus faecium that have either acquired or inherent resistance to third generation cephalosporins. In addition, increasing incidences of multi-drug resistant (MDR) gram-negative organisms in patients with cirrhosis have been implicated in therapeutic failure from third generation cephalosporins. Identifying patients with SBP at the highest risk for therapeutic failure with third generation cephalosporins, such as those that are critically ill, had recent antibiotic exposure, live in areas of the world with high rates of MDR organisms, or have nosocomial-acquired infections is important to improve clinical outcomes. Initiation of broader spectrum antibiotics to empirically cover additional gram-positive and MDR organisms in cirrhotic patients with SBP in these patients at higher risk for therapeutic failure may be appropriate.

Key References