Episode 19 Part 1: Pediatric Abdominal Pain and Appendicitis

In Part 1 of this Episode on Pediatric Abdominal Pain, Dr. Anna Jarvis, “the mother of pediatric emergency medicine” & Dr. Stephen Freedman, one of the world’s pre-eminent pediatric emergency medicine researchers, discuss the nuances of the history, physical and work up of Pediatric Abdominal Pain & Appendicitis and key pearls on how to distinguish serious surgical causes from the very common diagnosis of gastroenteritis.  An in-depth discussion on the pearls of the history, physical exam, lab tests, imaging including serial ultrasounds vs plain CT vs CT abdomen with contrast, clinical decision rules such as the Alvarado Score, best analgesics and antibiotics in pediatric appendicitis follows.

Dr. Jarivs and Dr. Freedman answer such questions as: What is the value of a urinalysis in kids with abdominal pain? What is the next step in the work-up of pediatric appendicitis when an ultrasound is ‘equivocal’? How can we optimize the accuracy of ultrasound in kids? Should we be using contrast when ordering a CT to rule out appendicitis? What is the value of inflammatory markers in the work-up of appendicitis? Which kids with appendicitis require antibiotics in the ED? Which kids with appendicitis do not require surgery? What are the most useful tips and tricks to use during your history and physical exam to maximize your diagnostic yield? and many many more……

Written Summary and blog post by Claire Heslop, edite by Anton Helman, December 2011

Most Common Diagnoses for Pediatric Abdominal Pain in the ED

  • In order of prevalence
    • 1. Gastroenteritis
    • 2. Respiratory Tract Infection (including Otitis Media, Pharyngitis and pneumonia)
    • 3. UTI
    • 4. Constipation
    • 5. Appendicitis

     

  • Aside from gastroenteritis, upper respiratory tract infection is the most common diagnosis written at the bottom of the emergency chart for missed appendicitis in kids!

 

Pediatric Appendicitis Presentation

  • The majority of cases of appendicitis in children <4y/o are perorated appendicitis, probably due to the atypical presentation and delay in diagnosis in this age group
  • This delay in diagnosis is due to the absence of the classic history of anorexia and vague periumbilical pain followed by migration of pain to the right lower quadrant and onset of fever and vomiting in many children
  • ‘Atypical is typical’ – diarrhea, constipation and dysuria are not uncommon and may lead the clinician astray; pain may localize to the back or psoas muscle as many children have a retrocecal appendix; vomiting may occur before abdominal pain (in contradistinction to the classic abdominal pain before vomiting in appendicitis) as younger children are unable to communicate their pain
  • Clues to perforation: Diarrhea is more likely to occur after perforation and temp is often higher; no localization of pain with peritoneal signs; if there is abscess formation you may feel a mass in the RLQ

 

Physical Exam of the Abdomen Pearls in Pediatric Patients

  • Children with appendicitis are usually lying still with the hips flexed as apposed to writhing in pain
  • Examine the child in their caretaker’s lap, or lying on top of their caregiver, or with their legs wrapped around their caregiver’s trunk, first with their clothes still on
  • Roll the patient’s hips and look for discomfort/pain with this maneuver Have the child palpate their own abdomen
    Percuss before you palpate!
  • Ask the child to ‘blow out the candles’ and look for respiratory splinting as the diaphragm lowers
  • The equivalent of ‘jump tenderness’ in infants and toddlers is having the caregiver bounce the child on their knee and observing for irritability
  • Examine the genitals of all boys with abdominal pain to look for testicular torsion!

 

Value of Lab Tests in Pediatric Patients with Abdominal Pain

  • About 1/4 of children with gastro will have elevated WBC (because dehydration and acidosis elevate the WBC) and many children with appendicitis will have a normal WBC; however, if the appendix is perforated, the vast majority of children will have an elevated WBC count.

Clinical Pearl: 

The earlier the presentation the less likely the WBC will be elevated.

The WBC is normal in first 24hrs in 80% of appendicitis cases.

  • CRP may be more sensitive than WBC in identifying a perforated appendix but cannot rule out appendicitis
  • Urinalysis (clean catch or catheter specimen): useful to rule out DKA, UTI, and pregnancy in teenagers as a cause for abdominal pain; sterile pyuria is consistent with appendicitis and gastro
  • ‘Finger‐prick’ Glucose: hypoglycaemia in severe gastro, hyperglycemia in DKA

Clinical Pearl:

Pyuria and hematuria are findings that can be consistent with the

diagnosis of appendicitis. Don’t let the findings of pyuria or hematuria

dissuade you from diagnosing appendicitis in a child who you suspect

has appendicitis clinically.

 

Imaging for Pediatric Appendicitis

  • Wide variation of practice when it comes to whether or not, and how to best image children suspected of having  appendicitis
  • First line is ultrasound which has a very high sensitivity and specificity for appendicitis, >95% respectively, but depends on technician skill, radiologist skill, patient co‐operation, patient girth (it is more difficult to obtain good images in obese patients), and whether or not the patient is given adequate anxiolysis and analgesic
  • Ultrasound criteria for appendicitis: tender and non‐compressible >6mm appendix, hyperemic appendix, wall thickness >1.7mm, plus secondary signs of thickening of mesenteric fat, free fluid, increased echogenicity, enlarged lymph nodes, abscess
  • Even if the appendix is not visualized on ultrasound, appendicitis can be excluded more confidently in the patient with low clinical pre‐test probability if ultrasonography shows no secondary signs of appendicitis (eg, hyperechoic mesenteric fat, fluid collection, localized dilated small bowel loop)
    If ultrasound is equivocal (eg: ‘appendix not seen’) and you still have clinical suspicion, consider surgical consultation and/or repeat physical exams, repeat blood work and repeat ultrasound
  • In some centres second line imaging is repeat ultrasound (ie a repeat ultrasound in 12hrs improves accuracy)
  • In other centres second line imaging is abdominal CT, which carries a life‐time cancer risk of about 1 in 1000 in children (the younger the child, the higher the risk)
  • For children with a very high clinical pre‐test probability for appendicitis, consider consulting surgeon for direct appendectomy without imaging
  • Some centres such as the British Columbia Children’s Hospital have a higher negative appendectomy rate for patients who do not get any imaging and go directly to the operating room and a higher perforation rate in patients who get imaging due to the delay in time to surgery
  • There is likely a happy medium between imaging all patients and taking all patients directly to the operating room

 

Clinical Pearl: 

While the accuracy of ultrasound for the diagnosis of appendicitis increases

with time from onset of symptoms, the accuracy of CT does not change with

time. It is therefore reasonable to repeat an abdominal ultrasound in 12-24

hours for patients with a low or moderate probability of appendicitis with

an equivocal initial ultrasound, who present early after symptom onset.

For more on ultrasound vs CT for appendicitis on ALiEM go here

 

Pediatric Pain Management and Anxiolytics

  • There is good evidence from at least 4 studies that administration of appropriate analgesics does change clinical decision‐making for appendicitis and may help the ultrasound technicians obtain a more accurate scan
  • There is good evidence that children are generally undertreated for pain in the ED
  • Anxiolytic medication (eg: intranasal midazolam) is helpful prior to imaging in selected patients
  • Analgesics
    • Morphine 0.1mg/kg (max 5mg), Fentanyl 1‐2micrograms/kg, Ketorolac 0.5‐1mg/kg
      Codeine: the clinical benefit is unpredictable as there is genetic variation in its metabolism so it has been removed from some pediatric emergency department formularies

     

Decision Rules for Pediatric Appendicitis

  • There is evidence that pediatric appendicitis decision rules decrease the use of CT scans by about 20%
  • Sensitivities are poor for decision rules when prospectively validated (Ann Emerg Med. 2007;49:778-784)
    but may be helpful in guiding clinicians who do not see pediatric patients on a regular basis
  • Alvarado Score
    • >6: sensitivity = 72% (1 pt each for ‐ migration of pain to RLQ, anorexia, nausea/vomiting, tenderness in RLQ, rebound pain, fever, leukocytosis, left shift)
  • Samuel Score
    • (‘Pediatric Appendicitis Score’) >5: sensitivity = 82% (1pt each for – RLQ tenderness elicited by cough, hopping or percussion, anorexia, fever, nausea/vomiting, tenderness over the right iliac fossa, leucocytosis, left shit, migration of pain

     

For more on appendicitis decision rules visit emDocs here

Treatment of Pediatric Appendicitis

  • Any  child  with  sepsis,  peritonitis,  perforated  appendix,  abscessed  appendix  requires  broad  spectrum antibiotics in the emergency department as soon as possible
  • In patients with non‐perforated appendicitis, antibiotics are given pre‐operatively on call to the operating room to decrease the incidence of wound infection and abscess formation
  • Patients with perforated appendicitis are usually managed conservatively with antibiotics, percutaneous drainage and interval surgery (surgery after 8‐12wks)

emcases-updateUpdate 2017: Two different meta-analyses have been published in March 2017 regarding Non-Operative Treatment (NOT) for pediatric Acute Uncomplicated Appendicitis (AUA). A meta-analysis of 5 studies (N=404) in JAMA Pediatrics found antibiotics for AUA had a success rate of 90.5%, with higher treatment failure in children with an appendicolith. A separate meta-analysis (10 studies, N=413) in Pediatrics found an initial treatment rate of 97% but a recurrence of 14% in those treated non-operatively. Overall, NOT may be an option for pediatric appendicitis but further studies need to be done prior to a change in current clinical practice. Appendectomy remains the treatment of choice at this time. Abstract 1 Abstract 2

 

Dr. Jarvis, Dr. Helman and Dr. Freedman have no conflicts of interest to declare.

 

Key References

1. Becker T, Kharbanda A, Bachur R. Atypical clinical features of pediatric appendicitis. Acad Emerg

Med. 2007; 14 (2): 124-9.

2. Bundy DG, Byerley JS, Liles EA, Perrin EM, Katnelson J, Rice HE. Does this child have appendicitis.

JAMA. 2007; 298 (4): 438-51.

3. Kharbanda AB, Casme Y, Liu K, Spitalnik SL, Dayan PS. Discriminative accuracy of novel and

traditional biomarkers in children with suspected appendicitis adjusted for duration of abdominal

pain. Acad Emerg Med. 2011; 18(6): 567-74.

4. Kwan KY, Nager AL. Diagnosing pediatric appendicitis: usefulness of laboratory markers. Am J

Emerg Med. 2010; 28 (9): 1000-15.

5. Kharbanda AB, Dudley NC, Bujaj L et al. Validation and refinement of a prediction rule to identify

children at low risk for acute appendicitis. Arch Pediatr Adolesc Med. 2012; 166 (8): 738-44.

6. Kulik DM, Uleryk EM, Maguire JL. Does this child have appendicitis? A systematic review of clinical

prediction rules for children with acute abdominal pain. Journal of Clinical Epidemiology. 2013; 66:

95-104.

7. Goldman RD, Crum D, Bromberg R, Rogovik A, Langer JC. Analgesia administration for acute

abdominal pain in the pediatric emergency department. Pediatric Emergency Care. 2006; 22 (1):

19-21.

8. Estey A, Poonai N, Lim R. Apprendix not seen: the predictive value of secondary inflammatory

sonographic signs. Pediatric emergency Care. 2006; 29 (4): 435 – 439.

9. Bachur RG, Dayan PS, Bajaj L et al. The effect of abdominal pain duration on the accuracy of

diagnostic imaging for pediatric appendicitis. Annals of Emergency Medicine. 2012; 60 (5): 582-

590.

10. Ohle R, O’Reilly F, O’Brien KK, et al. The Alvarado score for predicting acute appendicitis: a

systematic review. BMC Med. 2011;9:139.

11. Doria AS, Moineddin R, Kellenberger CJ, Epelman M et al. US or CT for diagnosis of appendicitis in

children and adults? A meta-analysis. Radiology. 2006; 241 (1): 81-94.

12. Antibiotics and appendicitis in the pediatric population: an American Pediatric Surgical

Association Outcomes and Clinical Trials Committee Systematic Review. Journal of Pediatric

Surgery, 2010, 45, 2181-2185.W

 

For more on Paediatric Emergencies download our free interactice eBook EM Cases Digest Vol. 2 Pediatric Emergenciesem cases digest pediatric emergencies

For more on pediatric abdominal pain on EM cases:
Episode 19 Part 2: Pediatric Gastroenteritis, Constipation and Bowel Obstruction

For more Pediatric EM learning visit trekk.ca – Translating Emergency Knowledge for Kids (TREKK) is a growing network of researchers, clinicians, health consumers and national organizations who want to accelerate the speed at which the latest knowledge in children’s emergency care is put into practice in general EDs – rural, remote or urban.

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About the Author:

Dr. Anton Helman is an Emergency Physician at North York General in Toronto. He is an Assistant Professor at the University of Toronto, Division of Emergency Medicine and the Education Innovation Lead at the Schwartz-Reisman Emergency Medicine Instititute. He is the founder, editor-in-chief and host of Emergency Medicine Cases.

2 Comments

  1. Dr romic June 9, 2017 at 2:46 pm - Reply

    Patients with perforated appendicitis are usually managed conservatively with antibiotics, percutaneous drainage and interval surgery (surgery after 8‐12wks). ???????

    I am a surgeon,and this is complete nonsense!!

    • Anton Helman June 9, 2017 at 3:49 pm - Reply

      Thanks for your comment. At the time of this podcast this was the recommended management for perforated appendicitis (http://emedicine.medscape.com/article/773895-treatment#d12). Subsequently there have been studies such as (Bonadio W, Rebillot K, Ukwuoma O, Saracino C, Iskhakov A. Management of pediatric perforated appendicitis: comparing outcomes using early appendectomy vs solely medical management. Pediatr Infect Dis J. 2015 Dec 14. [Medline].) that have suggested that early surgery may be superior.

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