Pediatric Appendicitis A Clinical Pathway

1. Pediatric AppendicitisA Clinical Pathway James Reingold, M.D. November 3,4 2011

2. James Reingold, M.D. • Medical Director, Cardon Children’s ED • Board Certified, PEM (Peds, Peds ER) • Member of the defunct ED Order Set Workgroup • Goals of standardizing care to “best practice” and reducing risk • Member of Peds CCG • 4+ years with “The Bannerman”

3. Risk Considerations • “The ED is often crowded, waits are long and privacy is limited. The ED environment is often one of excessive noise, high volume, and extreme pressure and stress.” • Especially weekends, holidays, evenings and nights spawn litigation (80%!) • The ED accounts for 45% of peds cases

4. Risk Considerations • By age 6 yrs, appendicitis is the 2nd most common diagnosis claim • Insurance co. complaints about Banner prolonged LOS and perforation rate • Testicular Torsion is #3 for boys 12-17 yrs, do your TSG course!

5. Pediatric Appendicitis • The most common surgical emergency in children • 70K appendectomies each yr in the US • Appendicitis is rare before age 1, when the appendix is “funnel shaped” • Appendicitis under age 4 results in perforation rates of 80-100%

6. Pediatric Appendicitis • Appendicitis incidence peaks at age 10-20 yrs because of lymphoid follicle hyperplasia, but perforation rate is only 10-20% • Taken together, children 0-17 have perforation rate of 33%

7. Radiation Concerns • Concern over missed appendicitis led to widespread use of CT • A clinical guideline at Harvard pushing CT imaging decreased both the negative appendectomy rate and admission for serial abdominal exams • Perforation rate was unchanged • CT rate increased from 5% to 60%

8. Radiation Concerns • Adult CT is more common but the rate of increase is larger among children, primarily because CT is now faster and does not require sedation • “The major growth area in CT use for children has been the presurgical diagnosis of appendicitis.”

9. Radiation Concerns • Children are at higher risk of radiation-induced carcinogenesis because of greater sensitivity to radiation as well as a longer life span to allow cancers to develop • They are also more likely to undergo further CT imaging as they age • Lifetime attributable risk of death from cancer from a SINGLE abd CT for a 5 y/o is 0.09% • Of 600K children/yr who undergo CT, 500 will develop cancer (slightly less than 1/10,000 risk)

10. Radiation Concerns • Atomic Bomb data • 25,000 survivors received a dose less than 50 mSv, mean dose 40 mSV • A single CT Abd study delivers 45-90 mSv radiation depending on age • 1.5-2% of all cancer in the US now attributable to CT imaging

11. Radiation Concerns • Is there a difference between “clean” radiation from GE and “dirty” radiation from an atomic bomb? • 400,000 radiation workers exposed to 20 mSv • Mortality from cancer correlated to radiation dose within 5-150 mSv • Correlated with A-bomb data

12. Alvarado Score • This study from 1986 published in Annals of Emergency Medicine was a retrospective review of 305 surgical admissions to Nazareth Hospital in Philadelphia • Charts pulled over 24 mos, 1975-76 • 74% prevalence of appendicitis! • Study Goal: Approach pts in a rational manner using a simple diagnostic score for observation vs surgery • Discussed a MANTRELS score to aid in diagnosis

13. MANTRELS • Migration of pain to the RLQ • Anorexia • Nausea/vomiting • Tenderness in the RLQ • Rebound tenderness • Elevation of temp • Leukocytosis • Shfit of WBC count

14. Evaluation of Alvarado Score • Bond, et al. Annals of Emergency Medicine, 1990 • 1st to stratify the score to specified risk levels • Among children with a score of 4 or lower, none had appendicitis • Other studies report negative likelihood ratio of 0.05 • (9% x 0.05=0.45%) • Score performed best among older children.

15. Evaluation of Alvarado Score • Three prospective studies show a score of 7 or higher increases the likelihood of appendicitis 4x (95% CI=3-5) • So 9% x 4=36% • Macklin, et al. Annals of the Royal College of Surgeons of England. • Performance unchanged by dropping S (left shift) • “Modified Alvarado,” this is what we are using

16. Clinical Practice Guidelines • Harvard has received the most attention • Surgical consultation BEFORE imaging • The Heidi Cox, MD memorial ED consult • If classic, to OR without labs • If concerning, labs • If imaging negative, home • Age <4 excluded

17. Clinical Practice Guidelines • Harvard Results • 34% appendicitis prevalence • 60% presented in 24 hours (earlier, was 36 hours for Alvarado) • Sensitivity and specificity were >95% • 60% use of CT, 18% use of CT + US

18. Ultrasonography • Annals of Emergency Medicine, Clinical Policy on Suspected Appendicitis, 2010 • Level B recommendation, use US “to confirm acute appy but not to definitively exclude it.” • Use CT “to confirm or exclude acute appy.” • Level C, “consider using US as the initial imaging modality. In cases in which the dx remains uncertain, CT may be performed.”

19. Ultrasound • What is a (+) US? • Diagnostic criteria for appendicitis are an appendix greater than 6 mm in diameter • A noncompressible appendix • Appendiceal tenderness. • Limitations • the appendix may be obscured (by bowel gas or overlying fat) or difficult to find (eg, retrocecal position)

20. Ultrasound • The 7 studies that evaluate the diagnostic accuracy of ultrasound in pediatric appendicitis support the idea that ultrasound is better at positively identifying appendicitis than excluding it • Although 3 of the 7 studies report negative likelihood ratios for US less than 0.1, 5 of these 7 studies report positive likelihood ratios greater than 10

21. Ultrasound • Sensitivity likely in the 88% range • Specificity in the 95% range • Operator specific, accuracy improves with the volume of studies performed • High volume centers report less “appendix not visualized”

22. Combining US and CT • Harvard warning • Karakas, et al, 1999. 633 children. Perforation rate increased “substantially” among pts who underwent both US and CT • This is presumed to be due to a delay in reaching the OR • In rural Canada, prolonged transfer to a pediatric surgeon correlated with perforatoin

23. Combining US and CT • Future Research: A study evaluating a Bayesian approach using ultrasound to diagnose appendicitis in children would be very helpful. For example, such a study would identify the probabilities of appendicitis in children with low, moderate, and high pre-test clinical suspicion.

24. Combining US and CT • From Schneider, et al (Annals, 2007) “One editorial argues that both ultrasonography and CT can have a role in diagnosis • According to the editorial, the main goal of imaging should be rational use of imaging resources and radiation dose reduction. • Perhaps the ideal scoring system could clearly stratify patients into those who can go directly to the operating room, those who should have radiologic imaging, and those who can be observed.”

25. Banner CPG (Finally!) • Assign a modified Alvarado Score • RLQ Pain (1 point) • Anorexia (1 point) • N/V (1 point) • RLQ TTP (1 point) • Rebound in RLQ (2 points) • Fever >37.5C (1 point) • WBC >10K (2 points)

26. Banner CPG • Stratify risk according to score • 0-3 low risk, send home with good follow-up • 4-6 intermediate risk, will require imaging • 7-9, high risk, send to Peds ER for surgical consultation, may be able to avoid imaging and speed time to OR, reduce risk of rupture • Avoid the radiation and delay of “confirming the diagnosis”

27. Banner CPG • Those children requiring imaging will undergo US if their body habitus is amenable • This will require transferring children to a Peds ED where experienced US techs and radiologists are present • Those children undergoing CT can stay put • This includes slim children whose pain has been >48 hours in duration

28. Limited CT Appendicitis Protocol • T-Bird developed a “Limited” CT for pediatric r/o appy • From L1 to symphysis pubis (pelvis only) • IV contrast only • Significantly reduced radiation and time to study completion • Indicated for pain <48 hours

29. CT with PO and IV contrast • Because of the increased rate of perforation and abscess formation, as well obstruction, children with pain >48 hours will still undergo CT Abd/Pelvis with both PO and IV contrast

30. Banner CPG • Children with (+) CT may be transferred to the inpatient pediatric service to await appendectomy • Children with a negative CT may be sent home or observed if needed • Children with a negative US should proceed to CT if there is high suspicion • Children with a (+) CT after US will go to OR

31. Cerner Clinical Decision Support • Cerner will apply these rules “behind the scenes” so that you can answer questions after the labs are back and appropriate orders will be suggested • This will allow Cerner to track the Alvarado score and the resulting physician order • Finally, Outcomes Research!!

32. Cerner Clinical Decision Support • Do I need to use Decision Support? • Yes! • Simplifies use of the new guideline • Allows quality control and tracking of expense • You must hit “done” to record the score but can delete orders from scratchpad

33. What will need to be tracked? • Use of CT (desired direction=less) • Rate of perforation (less) • Rate of negative appendectomy (stable) • Number of patients transferred and attendant cost (qualitative) • Number of children undergoing dual imaging (false negative rate of US) • Total cost of imaging (qualitative)

34. Expected Outcomes • Less use of CT in low pretest probability children • Increased use of US in mid-pretest probability children • Decreased use of any imaging in high pretest children, faster time to OR • Faster transfer to peds surgeon (less time at referral center), faster arrival in OR

35. Expected Outcomes • More children completing their evaluation in the Peds ED (being sent without imaging) • More chlidren moving to the Peds ED • Some children will have negative US and will be sent back home, but may have been spared CT or unnecessary direct admit