# Presentation: 075714

## Spotlight Case June 2003

**Missed Appendicitis**

**webmm.ahrq.gov**

## Source and Credits

- This presentation is based on June 2003 AHRQ WebM&M Spotlight Case in Surgery
- See the full article at _[http://webmm.ahrq.gov](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 WebM&M: Robert Wachter, MD
- Spotlight Editor: Tracy Minichiello, MD
- Managing Editor: Erin Hartman, MS

## 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)

## 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.*

## 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 2002;326:April 22. **Graff L, et al. Acad Emerg Med 2000;7:1244-55.*

**Notes:**
1. McCaig LF, N. L. National hospital ambulatory medical care survey: 2000 emergency department summary. Division of Health Care Statistics, Centers for Disease Control and Prevention. Number 326, April 22, 2002.
2.	Graff L, Russell J, Seashore J, et al. False-negative and false-positive errors in abdominal pain evaluation: failure to diagnose acute appendicitis and unnecessary surgery. Acad Emerg Med. 2000;7(11):1244-55.

## 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 2002;184:587-9.*

**Notes:**
Naoum JJ, Mileski WJ, Daller JA, Gomez GA, Gore DC, KimbroughTD, Ko TC, Sanford AP, Wolf SE. The use of abdominal computed tomography scan decreases the frequency of misdiagnosis in cases of suspected acute appendicitis. Am J Surg. 2002;184:587-9.

## 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 1996;276:1589-94.*

**Notes:**
Wagner JM, McKinney WP, Carpenter JL. Does this patient have appendicitis? JAMA. 1996;276(19):1589-94.

## 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 2002;75:721-5. **Maluccio MA. et al. Surg Infect 2001;2:205-11.*

**Notes:**

Ege G, Akman H, Sahin A, Bugra D, Kuzucu K. Diagnostic value of unenhanced helical CT in adult patients with suspected acute appendicitis. Br J Radiology 2002;75(897):721-5.
9.	Maluccio MA, Covey AM, Weyant MHJ, Eachempati SR, Hydo LJ, Barie PS. A prospective evaluation of the use of emergency department computed tomography for suspected acute appendicitis. Surg Infect. 2001;2(3):205-11.

## 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

## Case (cont.): Missed Appendicitis 

*Patient went to PCP’s 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.*

## “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 case—i.e., apply “metacognition”

**Notes:**
Metacognition:
“Given the same set of facts and circumstances, is there an alternative explanation that can be more accurate? Have all possibilities been taken into account? Are all issues properly addressed?” Applying this “big picture” assessment can prevent error. 

## 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. *

## Perforated Appendix

** **

**Notes:**
CT scan revealed a perforated appendix.

Contrast-enhanced CT image shows air and fluid in a mildly dilated and thickened appendix (arrow). There is adjacent periappendiceal infiltration (*).

CT findings consistent with appendicitis include enlarged, inflammed appendix and visualization of an appendolith. Other findings that may suggest appendicitis includepericecal inlfammation, periappendiceal fatty  infiltration, cecal thickening, small bowel obstruction and pevic abscess.

CLINICAL AND DIAGNOSTIC IMAGING CORRELATES IN APPENDICITIS IN CHILDREN: 
A Computer Aided Teaching Program
A Vade MD, CG Salomon MD , CL Kalbhen MD, JR Halama PhD
Loyola University Medical Center, Maywood, Illinois

## 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. *

## Intra-abdominal Abscess

## 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. *

## 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 2000;7:1244-55. **Mueller BA, et al. NEJM 1986;315:1506-8.*

**Notes:**
1.Graff L, Russell J, Seashore J, et al. False-negative and false-positive errors in abdominal pain evaluation: failure to diagnose acute appendicitis and unnecessary surgery. Acad Emerg Med. 2000;7(11):1244-55.

2.Mueller BA, Daling JR, Moore DE, et al. Appendectomy and the risk of tubal infertility. N Engl J Med. 1986;315(24):1506-8.
Appendiceal perforation increases the risk of wound infection, abscess formation, sepsis, wound dehiscence, pneumonia, prolonged ileus, heart failure, and renal insufficiency. Hospital stay is prolonged and delayed complications such as bowel obstruction are increased. In women, there is a five-fold increased risk of infertility 

## 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.*

## Challenges to Patient Safety in ED

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

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

- Encourage providers to use ED patient safety resources
- Increase teamwork
- Improve provider–patient communication

**Enhancing Patient Safety in ED**

*Wears RL, et al. Top Health Information Mgmt. 2002;23:1-12.*

**Notes:**
 Wears RL, Croskerry P, Shapiro M, Beach C, Perry S. Center for safety in emergency care: a developing center meant for evaluation and research in patient safety. Top Health Information Management. 2002;23(2):1- 12

## 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

## 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