Postpartum Endomyometritis Case File

Postpartum Endomyometritis Case File

Eugene C. Toy, MD, Patti Jayne Ross, MD, Benton Baker III, MD, John C. Jennings, MD

CASE 25

A 24-year-old G1P1 woman underwent a low-transverse cesarean section 2 days ago for arrest of active phase of labor. She required oxytocin and an internal uterine pressure catheter. She reached and persisted at 6-cm dilation for 3 hours despite adequate uterine contractions as judged by 240 Montevideo units. Her baby weighed 8 lb 9 oz. The past medical and surgical histories were unremarkable. She denies a cough or dysuria. On examination, the temperature is 102°F (38.8°C), heart rate is 80 beats per minute, blood pressure is 120/70 mm Hg, and respiratory rate is 12 breaths per minute. The breasts are nontender. The lungs are clear to auscultation. There is no costovertebral angle tenderness. The abdomen reveals that the skin incision is without erythema or tenderness. The uterine fundus is firm, at the level of the umbilicus, and somewhat tender. No lower extremity cords are palpated.

» What is the most likely diagnosis?

» What is the most likely etiology of the condition?

» What is the best therapy for the condition?

ANSWER TO CASE 25:

Postpartum Endomyometritis                                           

Summary: A 24-year-old G1P1 woman, who underwent a cesarean delivery 2 days previously for arrest of labor, has a fever of 102°F (38.8°C). She denies cough or dysuria. There are no abnormalities of the breasts, lungs, costovertebral region, or skin incision. The uterine fundus is somewhat tender.

• Most likely diagnosis: Endomyometritis.
• Most likely etiology of the condition: Ascending infection of vaginal organisms (anaerobic predominance but also Gram-negative rods).
• Best therapy for the condition: Intravenous antibiotics with anaerobic coverage (eg, gentamicin and clindamycin).

ANALYSIS

Objectives

1. Know that the most common cause of fever for a woman who has undergone cesarean delivery is endomyometritis.
2. Know the mechanism of the endomyometritis, that is, ascending infection of “polymicrobial” vaginal organisms.
3. Know that the differential diagnosis of fever in the woman who has undergone cesarean delivery includes mastitis, wound infection, atelectasis (if general anesthesia), and pyelonephritis.

Considerations

This 24-year-old woman underwent cesarean delivery for arrest of dilation with adequate uterine contractions (see Case 1 for criteria). She presumably had a long labor, an intrauterine pressure catheter, and numerous vaginal examinations. These are all risk factors for the development of postpartum endomyometritis. Other risk factors include low socioeconomic status, multiple gestations, young maternal age, Group B Step infection, chlamydia and manual extraction of the placenta. On examination, she has a fever up to 102°F (38.8°C). The scenario reveals that there are no abnormalities of the breasts, which rules out mastitis. The lungs are normal to auscultation, which speaks against atelectasis; in the obstetric patient, atelectasis is an uncommon cause of postoperative fever since the majority of cesarean deliveries are performed under regional anesthesia. This patient’s wound appears normal. There is no costovertebral angle tenderness, so the likelihood of pyelonephritis is low. Urinary tract infections involving only the bladder do not usually cause fever. The uterus is only somewhat tender, which does not overtly point to endomyometritis. However, when the remainder of the examination does not reveal a focus, the majority of women who have fever after cesarean delivery have endomyometritis.

APPROACH TO:

Fever after Cesarean Delivery                                           

DEFINITIONS

FEBRILE MORBIDITY: Temperature after cesarean delivery equal to or > 100.4°F (38°C) taken on two occasions at least 6 hours apart, exclusive of the first 24 hours.

ENDOMYOMETRITIS: Infection of the decidua, myometrium, and, sometimes, the parametrial tissues.

SEPTIC PELVIC THROMBOPHLEBITIS (SPT): Bacterial infection of pelvic venous thrombi, usually involving the ovarian vein.

CLINICAL APPROACH

A woman who has febrile morbidity after cesarean delivery most likely has endomyometritis. The use of perioperative antibiotics has decreased postoperative infection rate more than any other intervention but infections can still occur. The mechanism of infection is ascension of bacteria, a mixture of organisms from the normal vaginal flora. In other words, postcesarean delivery infection is almost always “polymicrobial,” with a mix of both aerobic and anaerobic bacteria. The uterine incision site, being devitalized and containing foreign material (ie, suture), is commonly the site for infection. Typically, the fever occurs on postoperative day 2. When intra-amniotic infection occurs during labor, the fever usually continues postpartum. The patient may complain of abdominal tenderness or a foul-smelling lochia. Uterine tenderness is common. Broad-spectrum antimicrobial therapy especially with anaerobic coverage is important. Intravenous gentamicin and clindamycin is a well-studied regimen and effective in 90% of cases. Other choices include extended penicillins or cephalosporins. In contrast to postcesarean infection, endometritis after vaginal delivery does not necessarily require anaerobic antimicrobial coverage, and ampicillin and gentamicin are usually sufficient. Regardless of route of delivery, the fever usually improves significantly after 48 hours of antimicrobial therapy. Enterococcal infection may be one reason for nonresponse; ampicillin is the treatment for this organism and often is added if fever persists after 48 hours of therapy. If fever persists despite triple antibiotic therapy for 48 to 72 hours, a computed tomography (CT) scan of the abdomen and pelvis may reveal an abscess, infected hematoma, or pelvic thrombophlebitis.

Another cause of fever after cesarean delivery is wound infection. Prophylactic antibiotics are given prior to surgery to decrease the incidence of infection. Thus, women who are scheduled to have cesarean, whether elective or in labor, should have a single-dose antibiotic prophylaxis prior to skin incision; this practice reduces the infection risk by about 75%. When a patient fails to respond to antibiotic therapy, wound infection is the most likely etiology. The fever usually occurs on postoperative day 4. Erythema or drainage may be present in the wound site. The organisms are often the same as those involved with endomyometritis. The treatment includes surgical opening of the wound (and dressing changes) and antimicrobial agents. The fascia must be inspected for integrity. Necrotizing fasciitis is a serious life-threatening infection that can affect the cesarean wound. Infections in the first 24 hours postoperatively can implicate group A streptococcus, the so-called “flesh-eating bacteria.” Immediate and extensive surgical debridement is indicated. Community-acquired methicillin-resistant Staphylococcus aureus has also been isolated with increasing frequency, affecting the skin incision.

Septic pelvic thrombophlebitis is a rare bacterial infection affecting thrombosed pelvic veins, usually the ovarian vessels. The bacterial infection at the placental implantation site spreads to the ovarian venous plexuses or to the common iliac veins, sometimes extending to the inferior vena cava. Women with SPT typically have recurrent high fevers and sometimes have a palpable pelvic mass. The diagnosis may be confirmed by a CT scan or magnetic resonance imaging. Treatment includes antimicrobial therapy and some practitioners will also use heparin therapy.

Other considerations in a febrile, woman should include pyelonephritis (fever, flank tenderness, leukocytes in the urine), pelvic abscess or infected pelvic hematoma, and breast engorgement (Table 25– 1).

CASE CORRELATON See also Case 24 (Necrotizing Fasciitis)

COMPREHENSION QUESTIONS

25.1 A 30-year-old G1P1 who underwent a cesarean section 3 days previously has a fever of 101°F (38.3°C). The skin incision is indurated, tender, and erythematous. Which of the following is the best management?

A. Initiation of intravenous ampicillin

B. Initiation of intravenous heparin

C. Placement of a warm compress on the wound

D. Opening of the wound

25.2 A 29-year-old woman is diagnosed with postpartum endometritis based on fever, abdominal pain, fundal tenderness, and elimination of other etiologies. Which of the following is the most significant risk factor for postpartum endomyometritis?

A. Numerous vaginal examinations

B. Bacterial vaginosis

C. Cesarean delivery

D. Internal uterine pressure monitors

E. Prolonged rupture of membranes

25.3 A 27-year-old G1P0 woman at 39 weeks’ gestation is noted to be in labor. She underwent artificial rupture of membranes, and experiences fetal bradycardia. Palpation of the vagina reveals a rope-like structure prolapsing through the cervix. She is diagnosed with a cord prolapse and underwent stat cesarean delivery. On postoperative day 2, the patient has a temperature of 102°F (38.8°C), and is diagnosed with endometritis. The patient who works in the microbiology laboratory asks which of the following is the most commonly isolated bacteria in her infection?

A. Peptostreptococcus species

B. Staphylococcus aureus

C. Group B Streptococcus

D. Escherichia coli

25.4 A 22-year-old woman who underwent cesarean delivery has persistent fever of 102°F (38.8°C), despite the use of triple antibiotic therapy (ampicillin, gentamicin, and clindamycin). The urinalysis, wound, breasts, and uterine fundus are normal on examination. A CT scan of the pelvis is suggestive of septic pelvic thrombophlebitis. Which of the following is the best therapy for this condition?

A. Hysterectomy

B. Discontinue antibiotic therapy and initiate intravenous heparin

C. Continue antibiotic therapy and begin intravenous heparin

D. Surgical embolectomy

E. Streptokinase therapy

ANSWERS

25.1 D. The best treatment of a wound infection is opening of the wound. Prophylactic antibiotics given during surgery decrease the likelihood of becoming infected. In addition to opening the wound, the patient should undergo dressing changes and be started on antimicrobial agents. The fascia must be inspected for integrity. In cesarean wound infections, there are two distinct populations of organisms that may be involved: skin organisms versus vaginal organisms. A Gram stain of the wound may direct toward the correct antibiotic regimen that would be effective for the possible bacteria.

25.2 C. Cesarean delivery greatly increases the risk of endometritis due to the fact that the patient most likely had prolonged rupture of membranes, numerous vaginal examinations, and an intrauterine pressure monitor due, for example, to an arrest of labor. Endometritis after vaginal delivery may occur as well, though less frequent, but does not necessarily require anaerobic antimicrobial coverage; therefore, ampicillin and gentamicin are usually sufficient.

25.3 A. Anaerobic bacteria are the most commonly isolated organisms in endomyometritis in patients who have undergone cesarean delivery. Peptostreptococcus and peptococcus are the most likely pathogens 45% of the time and bacteriodes 9%.The other organisms listed are aerobes.

25.4 C. Continue antibiotic therapy and begin intravenous heparin. Although there is no universal agreement, the best treatment for septic pelvic thrombophlebitis seems to be the combination of antibiotics and heparin. There are some practitioners who believe that antibiotics alone are sufficient to treat SPT. Heparin alone is not effective. Hysterectomy is not indicated.

    CLINICAL PEARLS    

» The most common cause of fever after cesarean delivery is endomyometritis. » The major organisms responsible for postcesarean endomyometritis are anaerobic bacteria with the most commonly isolated organisms include peptostreptococcus, peptococcus, and Bacteroides species. » Atelectasis is rare in obstetric patients due to the large number of women who have regional anesthesia. » When fever in a cesarean patient persists on triple antibiotic therapy, CT imaging should be performed. » Antibiotic therapy and heparin are an accepted treatment for septic pelvic thrombophlebitis.

REFERENCES

Aronoff DM, Mulla ZD. Postpartum invasive group A Streptococcal disease in the modern era. Infect Dis Obstet Gynecol. 2008;796-892. 

Costantine MM, Rahman M, Ghulmiyah L, et al. Timing of perioperative antibiotics for cesarean delivery: a metaanalysis. Am J Obstet Gynecol. 2008;199(3):301.e1. 

Cunningham FG, Leveno KJ, Bloom SL, Hauth JC, Gilstrap LC III, Wenstrom KD. Puerperal infection. In: Williams Obstetrics. 24th ed. New York, NY: McGraw-Hill; 2014:711-724, 661-668. 

Henderson K, Fuller K, Morosky C. ACOG: Green Journal Manual Exploration of the Uterus as a Risk Factor for Postpartum Endometritis. Obstetrics & Gynecology. 2015;124:81S. 

Kim M, Hyashi RH, Gambone JC. Obstetrical hemorrhage and puerperal sepsis. In: Hacker NF, Gambone JC, Hobel CJ, eds. Essentials of Obstetrics and Gynecology. 5th ed. Philadelphia, PA: Saunders; 2009:128-138.

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