Spotlight Case June 2003

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Spotlight Case June 2003

• Missed Appendicitis

webmm.ahrq.gov
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Source and Credits

• This presentation is based on June 2003 AHRQ
  WebMM Spotlight Case in Surgery
• See the full article at http//webmm.ahrq.gov
• CME credit is available through the Web site
• Commentary by James Adams, MD, Feinberg School
  of Medicine, Northwestern University
• Editor, AHRQ WebMM Robert Wachter, MD
• Spotlight Editor Tracy Minichiello, MD
• Managing Editor Erin Hartman, MS

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Objectives

• At the conclusion of this educational activity,
  participants should be able to
• Appreciate the variable presentation of
  appendicitis
• List complications of missed appendicitis
• Understand the advantages and disadvantages of CT
  in diagnosing appendicitis
• Define anchoring and metacognition and state
  their impact on missed diagnoses
• List potential strategies to enhance patient
  safety in the emergency department (ED)

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Case Missed Appendicitis

• A 37-year-old woman with no past medical history
  went to ED complaining of vomiting and
  periumbilical abdominal pain for 6 hours. On
  physical examination, she was afebrile, BP
  110/70, HR 85. Abdomen was soft, with no rebound
  or guarding. She was diagnosed with
  gastroenteritis, discharged with antiemetics, and
  told to return for persistent vomiting, pain, or
  new fever.

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Abdominal Pain in the ED

• Most common chief complaint in the ED
• 6 of the 100 million yearly ED visits
• Appendicitis is the most common surgical cause of
  abdominal pain
• 7 of population affected over a lifetime
• Small percentage of abdominal pain is due to
  appendicitis
• 1-3 of ED visits for abdominal pain are
  appendicitis

McCaig LF, et al. CDC 2002326April 22. Graff
L, et al. Acad Emerg Med 200071244-55.
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Challenge of Diagnosing Appendicitis

• Diagnosis uncommon clinicians accustomed to
  ruling out rather than ruling in disease
• High incidence of missed diagnoses due to low
  suspicion
• 20-40 misdiagnoses in some populations
• Implementation of diagnostic algorithm may combat
  this effect
• Reduce misdiagnosis rates to 6

Naoum JJ, et al. Am J Surg 2002184587-9.
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Challenge of Diagnosing Appendicitis

• Classic signs of appendicitis increase likelihood
  of disease
• Epigastric pain, radiating to RLQ, rebound, fever
• Classic presentation not typical
• WBC count normal in 10-30
• Early disease often presents with normal vitals,
  physical examination

Wagner JM, et al. JAMA 19962761589-94.
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Abdominal CT in Appendicitis

• CT can enhance diagnostic accuracy
• Sensitivity 80-100
• CT can delay diagnosis
• Reserve for men with atypical presentation and
  for women in whom pelvic pathology may mimic
  appendicitis
• CT in low-risk population will lead to increase
  in false positive readings
• Potential increase in unnecessary surgery

Ege G. et al. Br J Radiol 200275721-5.
Maluccio MA. et al. Surg Infect 20012205-11.
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Abdominal Pain in the ED

• Maintain suspicion for early disease
• Consider CT in appropriate population
• Consider inpatient observation
• Always provide detailed follow-up and discharge
  instructions
• Include warning signs and symptoms to prompt
  return visit to ED

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Case (cont.) Missed Appendicitis

• Patient went to PCPs office 2 days later with
  persistent abdominal pain vomiting had resolved.
  On physical exam, patient was afebrile, with
  normal vital signs. Abdomen was diffusely tender,
  with localization around the umbilicus. Pelvic
  exam revealed no cervical motion and mild adnexal
  tenderness. Diagnosis mittelschmerz vs. ovarian
  cyst. Transvaginal ultrasound ordered for
  following week. Patient told to take naproxen for
  pain.

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Anchoring

• Cognitive error due to reliance on diagnostic
  assumptions and prior reasoning of previous
  assessments
• Transition of care points are high risk for
  propagation
• To minimize this type of error, take a step back
  and think broadly about the casei.e., apply
  metacognition

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Case (cont.) Missed Appendicitis

• The next day, the patient returned to the ED with
  persistent pain. She was seen by the same ED
  attending, who then asked a colleague to evaluate
  the case. This second ED attending performed a
  pelvic exam and ordered a CT scan of the abdomen
  and pelvis. CT revealed a perforated appendix.

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Perforated Appendix

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Case (cont.) Missed Appendicitis

• The patient was seen by general surgery and it
  was decided not to take her to the operating room
  immediately due to the peritonitis. She was
  admitted and started on IV antibiotics. Her
  hospital stay was prolonged due to ileus. On
  hospital day number 8, her WBC count began to
  rise. A repeat CT scan was obtained.

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Intra-abdominal Abscess
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Case (cont.) Missed Appendicitis

• CT revealed an intra-abdominal abscess the size
  of an orange. The patient underwent percutaneous
  drainage by interventional radiology. On hospital
  day 13, she was discharged home with a plan to
  follow-up for elective appendectomy.

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Complications of Perforated Appendix

• Wound infection and dehiscence
• Intra-abdominal abscess
• Sepsis
• Prolonged ileus
• Pneumonia
• Bowel obstruction
• Infertility

Graff L, et al. Acad Emerg Med 200071244-55.
Mueller BA, et al. NEJM 19863151506-8.
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Case (cont.) Missed Appendicitis

• Shortly after discharge, the abdominal pain
  returned. The patient returned to the ED and
  underwent a repeat CT scan, which revealed a
  small bowel obstruction. The patient went to the
  operating room the next day for lysis of
  adhesions and appendectomy. Eight days later, the
  patient was discharged home. She has returned to
  her previous state of health.

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Challenges to Patient Safety in ED

• Excessive cognitive burden
• Time pressure
• Multiple interruptions
• No pre-existing relationship with patients

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Enhancing Patient Safety in ED

• Implement strategies to provide doctors with
  post-discharge feedback
• Encourage providers to use ED patient safety
  resources
• Increase teamwork
• Improve providerpatient communication

Wears RL, et al. Top Health Information Mgmt.
2002231-12.
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Take-Home Points

• Appendicitis is an uncommon but important cause
  of abdominal pain in the ED
• Presentation is often atypical
• Complications of missed or delayed diagnosis are
  multiple and morbid
• To decrease missed appendicitis, consider CT
  scan, inpatient observation, and/or detailed
  follow-up instructions
• Use CT scan with caution

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Take-Home Points (cont.)

• Avoid anchoring
• Always question conclusions of previous
  providers, particularly as new information
  accrues
• Consider implementing diagnostic algorithms to
  ensure that appendicitis is in the differential,
  even in atypical cases
• Close the loop by obtaining follow-up on
  clinical outcomes