Six days after a cesarean delivery, a 25-year-old woman comes to the emergency department with nausea, vomiting, and abdominal pain. The patient developed a sharp, right-sided abdominal pain 12 hours ago that has been increasing in severity, and she now has persistent nausea and vomiting. She has had no sick contacts, hematemesis, dysuria, or hematuria. Her last bowel movement was yesterday, with no blood in the stool. The patient has no chronic medical conditions and has had no surgeries other than the recent cesarean delivery. Temperature is 38.3 C (101 F), blood pressure is 110/70 mm Hg, pulse is 98/min, and respirations are 18/min. The surgical incision has minimal serosanguineous discharge with no associated fluctuance or mass. Abdominal examination shows tenderness over the right lower quadrant. There is guarding and rebound tenderness. Bowel sounds are decreased. Speculum examination shows no purulent discharge. The uterus is 14-week sized and nontender. Hemoglobin is 9.6 g/dL and leukocyte count is 21,000/mm3. Which of the following is the most likely diagnosis in this patient?
Acute appendicitis | |
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LLQ = left lower quadrant; RLQ = right lower quadrant. | |
This postpartum patient with right-sided abdominal pain most likely has acute appendicitis. Acute appendicitis develops after obstruction of the appendiceal lumen from a fecalith, cancer, or lymphoid follicular hyperplasia. The obstruction increases appendiceal intraluminal pressure, which occludes blood flow and results in ischemia. Patients initially develop referred periumbilical pain; in patients with recent abdominal surgery (eg, cesarean delivery), this pain may be masked. As ischemia progresses, patients develop systemic (eg, fever, leukocytosis) and localized (eg, right lower quadrant pain, rebound, guarding) signs of inflammation.
Immediately postpartum, the uterus decreases in size to the level of the umbilicus (ie, 20-week sized). The uterus undergoes gradual involution by 1-2 cm/day and may remain abdominally palpable (eg, 14-week sized) for up to 9 days postpartum. Therefore, atypical presentations of acute appendicitis can occur postpartum due to displacement of the appendix by the enlarged uterus.
(Choices B and D) Postpartum endometritis presents with fever and abdominal pain; however, it also causes uterine tenderness, purulent lochia, and heavy vaginal bleeding (not seen in this patient). Septic pelvic thrombophlebitis is a rare diagnosis associated with endometritis and is characterized by relapsing-remitting fevers. However, neither diagnosis causes rebound or guarding (ie, peritoneal signs) because the infection is either contained in the uterine cavity (endometritis) or in the retroperitoneum (septic pelvic thrombophlebitis).
(Choices C and E) Patients with a fascial dehiscence or a strangulated incisional hernia can present postoperatively with nausea and abdominal pain. However, patients usually have copious serosanguineous discharge and either an incisional bulge or fluctuant mass (ie, bowel).
(Choice F) Uterine incarceration is a rare disorder that occurs during pregnancy as a retroverted uterus enlarges and the fundus becomes entrapped under the sacral promontory. Patients have pelvic pain and urinary retention due to bladder obstruction. Uterine incarceration does not occur postpartum because the uterus becomes progressively smaller (involutes) and is therefore unlikely to become entrapped.
Educational objective:
Acute appendicitis typically presents with fever, nausea, vomiting, and right lower quadrant pain. Diagnosis of acute appendicitis is mainly clinical, but atypical presentations can occur postpartum due to displacement of the appendix by the enlarged uterus.