Evidence Based Appy

Evidence Based Approach to Appendicitis
EBM summary

Epidemiology
Males>Females @ 1.4:1 (lifetime risk 8.6%, 6.7% respectively)
Females have higher negative appendectomy rate
Most common between the ages of 5-50
Peak incidence 10-14yo (males) and 15-19yo (females)
Risk factors: smoking, low fiber diet, Caucasian ethnicity, summermonths

Anatomy
Retrocecal>pelvic>subcecal>preilial>postilieal
11% of retrocecal appendices extend into the retroperitoneum
Might present as R flank pain
Obstruction causes inflammation in 50% of cases and can occur anywhere along the length of the appendix
Tip appendicitis is inflammation of the distal-most aspect, common cause of false-negative CT scans
McBurney’s Point

Pathophysiology
5 Stages of Appendicitis
Appendiceal obstruction, luminal distension
T8-T10 visceral afferent nerve irritation (periumbilical pain)
Lasts 4-6h classically
Intraluminal pressure>local venous pressure resulting in tissue ischemia and vascular congestion
Ischemia induces inflammation and local bacterial invasion
Inflammation extends extraluminally leading to parietal peritoneal inflammation and focal pain

Variations on Classic Presentation
Perforation rate is 80% if diagnosis is delayed >48h from the onset of pain
Recurrent Appendicitis
Patient with ≥1 episode of similar pain in the past
Subacute/Chronic Appendicitis
Abdominal pain lasting days-weeks that is relieved post-appendectomy
Delayed presentations often have CT e/o inflammation
History of prior abdominal pain has poor NPVfor acute appy

Why do I need my appendix, doctor?
You can tell your patient one of the following…
We really don’t know
It served its purpose when you were young helping develop your immune system, but it’s purpose greatly decreased after about the age of 5 years old
It acts as a reservoir for commensal bacteria, offering re-inoculation of the colon should all your normal flora be wiped out

Differential Diagnosis
Enteritis (Yersinia, Campylobacter, Salmonella)
Omental infarction (NEC in kids)
Epiploicappendigits (mesenteric adenitis in kids)
UTI/pyelo
Nephrolithiasis
Hernia
Bowel obstruction
Cecaldiverticulits (Meckel’s)
Cecal volvulus (intuss in kids)
Testicular/ovarian torsion
PID/TOA
Ruptured ovarian follicle/ectopic pregnancy

Physical Examination
RLQ TTP (specifically McBurney’s) and rigidity are most predictive of acute appy
Rebound, guarding, fever, and psoas sign have additive value
Pain on rectal exam, Rovsing’s sign, increased RLQ skin temperature have no diagnostic value
Psoas (13-42% sens, 79-95% spec) if performed correctly!
Obturator (8% sens, 94% spec)

History
“Classic” presentation is rare (~6%)
Anorexia is not a helpful marker
2010 ACEP Clinical Policy on suggestive findings for acute appy
RLQ pain, pain migration, pain progression
ALVARADO/MANTREL SCORE
Migratory abdominal pain to RLQ (1)
Anorexia/ketonuria (1)
Nausea/vomiting (1)
TTP to RLQ (2)
Rebound tenderness (1)
Elevated temp >37.5C (1)
Leukocytosis >10 (2)
0-3: Low probability
4-6: Moderate probability
>7: High probability
95% sens, 83% diag accuracy (M>F)
PEADIATRIC ASSESSMENT SCORE
Anorexia (1)
Nausea/vomiting (1)
Migratory pain (1)
Fever > 38C (1)
RLQ pain w/ cough/hopping (2)
RLQ TTP (2)
WBC >10k (1)
Bandemia >7500 (1)
0-2: Low risk (2% false positive
3-6: Inderterminant
>7: High risk (96% specificity)

Appendicitis Inflammatory Response Score
Shows decent diagnostic value better than Alvarado
73% true negatives and 67% true positives identified
Only 37% left indeterminant
Alvarado -> 61%, 40%, 48%, respectively
Vomiting (1)
RLQ Pain (1)
RT or Guarding (light (1), medium (2), strong (3))
Temp > 38.5C (1)
PMN count (70-84% (1), ≥85% (2))
WBC count (10-14.9 (1), ≥15 (2))
CRP (1-4.9 (1), ≥5 (2))
0-4: Low Prob (o/p f/u supported)
5-8: Indeterminate (serial exams or further testing required)
≥9: High Prob (surgical exploration proposed)

Unique Workup Options
Stool guiac
Heme-positive diarrhea suggestive of enteroinvasive bacteria
UA
>30RBC/hpfor >20WBC/hpf suggests UTI>appy
Cervical motion tenderness
Can be seen with any peritoneal inflammation, non-specific
Significant if associated with pelvic discharge
WBC + CRP (a fool makes a judgment based on WBC alone!)
WBC alone has low diagnostic value
WBC>10 and CRP>8 has notable predictive power
WBC>15 and PMN>85% is slightly useful

Treatment
IV opioids
DOES NOT mask physical exam findings
Antibiotics vs placebo – no difference in post-op findings histologically
Augmentin, cefotetan, clindamycin should NOT be considered (high resistance patterns in E.coli and B.fragilis)
MRSA coverage not necessary
FQs showing rapidly emerging E.coli resistance patterns

Evidence Based Appy

by Gromimd on Oct 08, 2011

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Evidence Based Appy — Presentation Transcript