Diagnosis of Acute Appendicitis Jim Holliman, M.D., F.A.C.E.P. Professor of Military and Emergency...

Diagnosis of Diagnosis of Acute Acute

Appendicitis Appendicitis

Jim Holliman, M.D., F.A.C.E.P.Jim Holliman, M.D., F.A.C.E.P.Professor of Military and Emergency Professor of Military and Emergency MedicineMedicineUniformed Services University of the Health Uniformed Services University of the Health SciencesSciencesClinical Professor of Emergency MedicineClinical Professor of Emergency MedicineGeorge Washington UniversityGeorge Washington UniversityBethesda, Maryland, USABethesda, Maryland, USA

ObjectivesObjectives

To review the pathophysiology To review the pathophysiology and clinical presentation of acute and clinical presentation of acute appendicitisappendicitis

To understand which patient To understand which patient groups are at high risk of groups are at high risk of misdiagnosismisdiagnosis

To discuss the use of laboratory To discuss the use of laboratory and imaging studies in the and imaging studies in the diagnosis of acute appendicitisdiagnosis of acute appendicitis

Appendicitis Incidence & Appendicitis Incidence & ComplicationsComplications

6 % lifetime incidence6 % lifetime incidence69 % are ages 10 to 3069 % are ages 10 to 30Up to 30 % misdiagnosed initiallyUp to 30 % misdiagnosed initially20 to 30 % ruptured at surgery20 to 30 % ruptured at surgeryMortality : 0.1 to 0.2 % Mortality : 0.1 to 0.2 % unruptured, 3 to 5 % rupturedunruptured, 3 to 5 % ruptured

Significant morbiditySignificant morbidity

Anatomic AspectsAnatomic Aspects

Blind pouch off of cecumBlind pouch off of cecumContains lymphoid tissue which Contains lymphoid tissue which peaks in adolescence, atrophies peaks in adolescence, atrophies with agewith age

Function still unclearFunction still unclearAppendix can be anywhere within Appendix can be anywhere within peritoneal cavityperitoneal cavity

One study showed 65 % retrocecal, One study showed 65 % retrocecal, 31 % pelvic31 % pelvic

Review of 70,000 cases showed 4 Review of 70,000 cases showed 4 % in RUQ, 0.06 % LUQ, 0.04 % LLQ% in RUQ, 0.06 % LUQ, 0.04 % LLQ

Pathophysiology of Pathophysiology of AppendicitisAppendicitis

Lymphoid hyperplasia leads to luminal Lymphoid hyperplasia leads to luminal obstructionobstruction

Often follows viral illnessOften follows viral illnessEpithelial cells secrete mucusEpithelial cells secrete mucusAppendix distends, bacteria multiplyAppendix distends, bacteria multiplyVisceral pain begins an average of 17 Visceral pain begins an average of 17 hours after obstructionhours after obstruction

Increased pressure compromises blood Increased pressure compromises blood supplysupply

Somatic pain developsSomatic pain developsAverage time to perforation = 34 hrs.Average time to perforation = 34 hrs.

Classic PresentationClassic Presentation

Seen in 60 %Seen in 60 %AnorexiaAnorexiaPeriumbilical pain, nausea, Periumbilical pain, nausea, vomitingvomiting

RLQ pain developing over 24 hrs.RLQ pain developing over 24 hrs.Anorexia and pain are most Anorexia and pain are most frequentfrequent

Usually nausea, sometimes Usually nausea, sometimes vomitingvomiting

Diarrhea, esp. with pelvic locationDiarrhea, esp. with pelvic locationUsually tender to palpationUsually tender to palpationRebound is a later findingRebound is a later finding

Physical ExamPhysical Exam

Tenderness at McBurney's pointTenderness at McBurney's pointCutaneous hyperesthesia in T 10 Cutaneous hyperesthesia in T 10 to 12 dermatomesto 12 dermatomes

Rovsing's signRovsing's signPsoas signPsoas signObturator signObturator sign

MANTRELS ScoreMANTRELS Score

Established in 1986Established in 1986MMigration of painigration of painAAnorexianorexiaNNausea / vomitingausea / vomitingTTenderness RLQenderness RLQRReboundeboundEElevated temp.levated temp.LLeukocytosiseukocytosisSShift to lefthift to left

MANTRELS Score, cont'd.MANTRELS Score, cont'd.

RLQ tenderness and leukocytosis RLQ tenderness and leukocytosis = 2 points each ; all others 1 = 2 points each ; all others 1 pointpoint

Score of 5 to 6 = possible Score of 5 to 6 = possible appendicitisappendicitis

Score of 7 to 8 = probable Score of 7 to 8 = probable appendicitisappendicitis

Score of 9 to 10 = very probable Score of 9 to 10 = very probable appendicitisappendicitis

High Risk PatientsHigh Risk Patients

Ovulating womenOvulating womenPID, TOA, ovarian cyst rupture can PID, TOA, ovarian cyst rupture can mimic appendicitismimic appendicitis

Look for cervical motion Look for cervical motion tenderness, adnexal tenderness, tenderness, adnexal tenderness, history of STD’shistory of STD’s

Can have CMT with pelvic appendixCan have CMT with pelvic appendix

High Risk Patients, cont'd.High Risk Patients, cont'd.

PregnancyPregnancyMost common surgical emergency Most common surgical emergency in pregnancyin pregnancy

Mortality rate if missed = 2 % for Mortality rate if missed = 2 % for mother, up to 35 % for fetusmother, up to 35 % for fetus

WBC elevated in pregnancyWBC elevated in pregnancyAppendix changes locationAppendix changes location


PediatricsPediatricsMost common surgical disorder in kidsMost common surgical disorder in kidsAccounts for 5 % of abd. pain visitsAccounts for 5 % of abd. pain visitsUp to 50 % initially misdiagnosedUp to 50 % initially misdiagnosed

ƒ < 2 yrs. : perforation rate approaches 100 %< 2 yrs. : perforation rate approaches 100 %ƒ 3 to 5 yrs. = 71 %3 to 5 yrs. = 71 %ƒ 6 to 10 yrs. = 40 %6 to 10 yrs. = 40 %

Most common misdiagnosis is AGEMost common misdiagnosis is AGESequence of pain and vomiting may be Sequence of pain and vomiting may be helpfulhelpful

Localized tenderness not a feature of Localized tenderness not a feature of AGE AGE


ElderlyElderlyVital signs and exam may not Vital signs and exam may not reflect severityreflect severity

> age 60 : only 5 to 10 % > age 60 : only 5 to 10 % diagnosed without delaydiagnosed without delay

Perforation rate = 46 to 83 %Perforation rate = 46 to 83 %RLQ tenderness absent in 23 %RLQ tenderness absent in 23 %N/V, anorexia less commonN/V, anorexia less commonLeukocytosis less pronouncedLeukocytosis less pronouncedOnly 20 % classic presentationOnly 20 % classic presentation


ImmunocompromisedImmunocompromisedHIV, chronic steroids, sickle cell, HIV, chronic steroids, sickle cell, chemotherapy, DM, dialysischemotherapy, DM, dialysis

Increased risk of complications and Increased risk of complications and misdiagnosismisdiagnosis

Inflammatory response decreasedInflammatory response decreased

Differential DiagnosisDifferential Diagnosis

GastroenteritisGastroenteritisMesenteric Mesenteric lymphadenitislymphadenitis

PIDPIDMittelschmertzMittelschmertzCrohn's diseaseCrohn's diseaseDiverticulitisDiverticulitisEndometriosisEndometriosis

TOATOAEctopic Ectopic pregnancypregnancy

UTIUTIPyelonepritisPyelonepritisOther processes Other processes involving involving appendixappendix

" No single evaluation can " No single evaluation can substitute for the substitute for the diagnostic accuracy of the diagnostic accuracy of the experienced physician."experienced physician."

Laboratory StudiesLaboratory Studies

CBCCBC75 to 85 % have elevated WBC, but 75 to 85 % have elevated WBC, but it is nonspecificit is nonspecific

WBC normal in 80 % in the first 24 WBC normal in 80 % in the first 24 hrs.hrs.

Can see elevated ANC in up to 89 Can see elevated ANC in up to 89 %%

WBC usually 12 to 18,000 in WBC usually 12 to 18,000 in appendicitisappendicitis

Chemistry panelChemistry panelMay help with diagnosis of May help with diagnosis of dehydrationdehydration

Laboratory Studies, cont'd.Laboratory Studies, cont'd.

UrinalysisUrinalysisSpecific gravity, ketonesSpecific gravity, ketonesCan see WBC’s, RBC’s, bacteria if Can see WBC’s, RBC’s, bacteria if inflamed appendix close to ureterinflamed appendix close to ureter

> 30 WBC’s = probable UTI> 30 WBC’s = probable UTIHCG HCG Essential in women of child-Essential in women of child-bearing agebearing age

CRPCRPAcute phase reactantAcute phase reactant

Imaging StudiesImaging Studies

Plain filmsPlain filmsLow sensitivity and specificityLow sensitivity and specificityAppendicolith specific, but seen in Appendicolith specific, but seen in only 2 %only 2 %

May see local air-fluid levels, psoas May see local air-fluid levels, psoas obliteration, soft tissue mass, gas in obliteration, soft tissue mass, gas in appendix : all nonspecificappendix : all nonspecific

Imaging Studies, cont'd.Imaging Studies, cont'd.

UltrasoundUltrasound75 to 90 % sensitive, 86 to 100 % 75 to 90 % sensitive, 86 to 100 % specificspecific

Noninvasive, low cost, but Noninvasive, low cost, but operator-dependentoperator-dependent

Good for diagnosing GYN disordersGood for diagnosing GYN disorders3 criteria for diagnosis3 criteria for diagnosis

ƒ Tender, noncompressible Tender, noncompressible appendixappendix

ƒ No peristalsis of appendixNo peristalsis of appendixƒ Overall diameter > 6 mmOverall diameter > 6 mm


Ultrasound (US)Ultrasound (US)Appendix may not be seen, due to Appendix may not be seen, due to obesity, guarding, bowel gas, obesity, guarding, bowel gas, perforation, retrocecal locationperforation, retrocecal location

2.4 to 56 % of normal appendixes 2.4 to 56 % of normal appendixes seenseen

One study of 736 pediatric patients One study of 736 pediatric patients showed 36.6 % without preop US showed 36.6 % without preop US had negative appendectomy vs. 9.8 had negative appendectomy vs. 9.8 % who had US% who had US


UltrasoundUltrasoundStudy from Australia showed total Study from Australia showed total WBC and neutrophil count were WBC and neutrophil count were more accurate than US. They more accurate than US. They recommended pts. with recommended pts. with unequivocal presentation go to OR. unequivocal presentation go to OR. If equivocal, obtain CBC. If WBC > If equivocal, obtain CBC. If WBC > 15,000, go to OR. If < 11,000, 15,000, go to OR. If < 11,000, obtain CT (US only in pregnancy).obtain CT (US only in pregnancy).


CTCTEarly studies showed low yield, but Early studies showed low yield, but helical CT much more accuratehelical CT much more accurate

Sensitivity 97 to 100 %, specificity Sensitivity 97 to 100 %, specificity 95 % (similar no matter what type 95 % (similar no matter what type or whether contrast is used)or whether contrast is used)

Often shows alternative diagnosisOften shows alternative diagnosisMore expensive, radiation More expensive, radiation exposureexposure


CTCTCriteria for appendicitis :Criteria for appendicitis :

ƒ Diameter > 6 mmDiameter > 6 mmƒ Failure to completely fill with Failure to completely fill with contrast or aircontrast or air

ƒ AppendicolithAppendicolithƒ Wall thickening or enhancementWall thickening or enhancement

Other contributory signs include Other contributory signs include fat stranding, fluid, inflammatory fat stranding, fluid, inflammatory mass, adenopathymass, adenopathy


CTCTOne study showed negative One study showed negative laparotomy rates of 4 % in men, 8 laparotomy rates of 4 % in men, 8 % in ovulating women with CT % in ovulating women with CT (typical is 20 % and 45 % (typical is 20 % and 45 % respectively), but no change in respectively), but no change in perforation rateperforation rate

Another study showed increase in Another study showed increase in CT use led to earlier diagnosis, less CT use led to earlier diagnosis, less severe pathologic findings, and severe pathologic findings, and decreased length of staydecreased length of stay


CTCTStudy from Dept. of Surgery, Study from Dept. of Surgery, Stamford, Connecticut : use of CT Stamford, Connecticut : use of CT markedly increased from 1994 to markedly increased from 1994 to 2000, without change in rate of 2000, without change in rate of negative appendectomy. They negative appendectomy. They concluded use of CT by concluded use of CT by nonsurgeons leads to increased nonsurgeons leads to increased E.D. LOS without improving E.D. LOS without improving accuracy. They recommend accuracy. They recommend mandatory surgical consult if CT mandatory surgical consult if CT considered.considered.

Do We Need Imaging Do We Need Imaging Studies?Studies?

Literature conflictingLiterature conflictingPediatric Imaging -Evidence-Pediatric Imaging -Evidence-Based GuidelinesBased GuidelinesImaging most useful in clinically Imaging most useful in clinically equivocal casesequivocal cases

Costs of imaging minor compared Costs of imaging minor compared to cost of unnecessary surgery or to cost of unnecessary surgery or delayed diagnosisdelayed diagnosis

US and CT both specific enough to US and CT both specific enough to rule in appendicitis, but only CT rule in appendicitis, but only CT sensitive enough to rule it outsensitive enough to rule it out


Study from AustriaStudy from Austria350 patients divided into low, 350 patients divided into low, intermediate, and high probabilityintermediate, and high probability

All had USAll had US10 % of low prob., 24 % of 10 % of low prob., 24 % of intermediate prob., and 65 % of intermediate prob., and 65 % of high prob. had appendicitishigh prob. had appendicitis

Specificity and sensitivity of US = Specificity and sensitivity of US = 98 %98 %

Concluded imaging should be done Concluded imaging should be done even in high probability patientseven in high probability patients


NEJMNEJM : Suspected Appendicitis Jan. : Suspected Appendicitis Jan. 20032003Patients with classic presentation Patients with classic presentation should go to O.R. Diagnostic accuracy should go to O.R. Diagnostic accuracy approaches 95 %approaches 95 %

If equivocal or suspect perforation : CTIf equivocal or suspect perforation : CTUS reserved for pregnant women or US reserved for pregnant women or high suspicion of GYN diseasehigh suspicion of GYN disease

If study indeterminate, observe with If study indeterminate, observe with repeated exams or laparoscopyrepeated exams or laparoscopy

AnalgesiaAnalgesia

Sir Zachary Cope's 1921 textbook Sir Zachary Cope's 1921 textbook of surgery said no wayof surgery said no way

Prospective studies (both EM and Prospective studies (both EM and Surgery literature) now show Surgery literature) now show appropriate use of IV narcotics appropriate use of IV narcotics does not decrease diagnostic does not decrease diagnostic accuracy, and may improve examaccuracy, and may improve exam

Analgesia, cont'd.Analgesia, cont'd.

Journal of American College of Surgeons Journal of American College of Surgeons : Jan. 2003: Jan. 2003Prospective, randomized, double blind Prospective, randomized, double blind studystudy

Adults with abd. pain got up to 15 mg Adults with abd. pain got up to 15 mg morphine vs. placebomorphine vs. placebo

Increased pain relief, with no change in Increased pain relief, with no change in diagnostic accuracydiagnostic accuracy

Not all surgeons read their own Not all surgeons read their own literature, so give them a chance to literature, so give them a chance to come in a reasonable time frame or give come in a reasonable time frame or give the medsthe meds

Risk ManagementRisk Management

Misdiagnosis of appendicitis = Misdiagnosis of appendicitis = 5th leading cause of successful 5th leading cause of successful litigation against EPslitigation against EPs

7 features of misdiagnosed 7 features of misdiagnosed cases :cases :No nausea / vomitingNo nausea / vomitingLack of distressLack of distressNo reboundNo reboundNo guardingNo guardingNo rectal exam (controversial)No rectal exam (controversial)Narcotic pain meds givenNarcotic pain meds givenDiagnosis of acute gastroenteritisDiagnosis of acute gastroenteritis

Risk Management, cont'd.Risk Management, cont'd.

When discharging, stress unclear When discharging, stress unclear diagnosis, what to watch fordiagnosis, what to watch for

Follow up in 12 hours (PMD or Follow up in 12 hours (PMD or E.D.)E.D.)

Can always observe if unsureCan always observe if unsure"When in doubt, don't send them "When in doubt, don't send them out."out."

SummarySummary

Appendicitis is a common surgical Appendicitis is a common surgical emergency with a varied clinical emergency with a varied clinical presentationpresentation

Several patient groups are at Several patient groups are at high risk of misdiagnosishigh risk of misdiagnosis

Lab and imaging studies are Lab and imaging studies are helpful, but no single study is a helpful, but no single study is a substitute for good clinical substitute for good clinical judgementjudgement

Diagnosis of Acute Appendicitis Jim Holliman, M.D., F.A.C.E.P. Professor of Military and Emergency...

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