CASE Woman who has undergone recent cesarean delivery
A 23-year-old woman had a primary cesarean delivery 72 hours ago due to an arrest of dilation at 6 cm. She was in labor for 22 hours, and her membranes were ruptured for 18 hours. She had 10 internal vaginal examinations, and the duration of internal fetal monitoring was 12 hours; 24 hours after delivery, she developed a fever of 39°C, in association with lower abdominal pain and tenderness. She was presumptively treated for endometritis with cefepime; 48 hours after the initiation of antibiotics, she remains febrile and symptomatic.
- What are the most likely causes of her persistent fever?
- What should be the next steps in her evaluation?
Cesarean delivery background
Cesarean delivery is now the most common major operation performed in US hospitals. Cesarean delivery rates hover between 25% and 30% in most medical centers in the United States.1 The most common postoperative complication of cesarean delivery is infection. Infection typically takes 1 of 3 forms: endometritis (organ space infection), wound infection (surgical site infection), and urinary tract infection (UTI).1 This article will review the initial differential diagnosis, evaluation, and management of the patient with a postoperative fever and also will describe the appropriate assessment and treatment of the patient who has a persistent postoperative fever despite therapy. The article will also highlight key interventions that help to prevent postoperative infections.
Initial evaluation of the febrile patient
In the first 24 to 48 hours after cesarean delivery, the most common cause of fever is endometritis (organ space infection). This condition is a polymicrobial, mixed aerobic-anaerobic infection (FIGURE). The principal pathogens include anaerobic gram-positive cocci (Peptococcus and Peptostreptococcus species), aerobic gram-negative bacilli (primarily Escherichia coli, Klebsiella pneumoniae, and Proteus species), and aerobic gram-positive cocci (group B Streptococcus, Enterococcus, and Staphylococcus).1
The major risk factors for postcesarean endometritis are extended duration of labor and ruptured membranes, multiple internal vaginal examinations, invasive fetal monitoring, and pre-existing colonization with group B Streptococcus and/or the organisms that cause bacterial vaginosis. Affected patients typically have a fever in the range of 38 to 39°C, tachycardia, mild tachypnea, lower abdominal pain and tenderness, and purulent lochia in some individuals.1
Differential for postoperative fever
The initial differential diagnosis of postoperative fever is relatively limited (TABLE 1). In addition to endometritis, it includes extensive atelectasis, perhaps resulting from general anesthesia; lower respiratory tract infection, either viral influenza or bacterial pneumonia; and acute pyelonephritis. A simple infection of the bladder (cystitis or asymptomatic bacteriuria) should not cause a substantial temperature elevation and systemic symptoms.1
Differentiation between these entities usually is possible based on physical examination and a few laboratory tests. The peripheral white blood cell count usually is elevated, and a left shift may be evident. If a respiratory tract infection is suspected, chest radiography is indicated. A urine culture should be obtained if acute pyelonephritis strongly is considered. Lower genital tract cultures are rarely of value, and uncontaminated upper tract cultures are difficult to obtain. I do not believe that blood cultures should be performed as a matter of routine. They are expensive, and the results are often not available until after the patient has cleared her infection and left the hospital. However, I would obtain blood cultures in patients who meet one of these criteria1,2:
- They are immunocompromised (eg, HIV infection).
- They have a cardiac or vascular prosthesis and, thus, are at increased risk of complications related to bacteremia.
- They seem critically ill at the onset of evaluation.
- They fail to respond appropriately to initial therapy.
The cornerstone of therapy is broad spectrum antibiotics that target the multiple organisms responsible for endometritis.3 There are several single agents and several combination antibiotic regimens that provide excellent coverage against the usual pelvic pathogens (TABLE 2). I personally favor the generic combination regimen (clindamycin plus gentamicin) because it is relatively inexpensive and has been very well validated in multiple studies. In patients who have underlying renal dysfunction, aztreonam can be substituted for gentamicin.
Approximately 90% of patients will show clear evidence of clinical improvement (ie, decrease in temperature and resolution of abdominopelvic pain) within 48 hours of starting antibiotics. Patients should then continue therapy until they have been afebrile and asymptomatic for approximately 24 hours. At that point, antibiotics should be discontinued, and the patient can be discharged. With rare exceptions, there is no indication for administration of oral antibiotics on an outpatient basis.1,4
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