Evidence-based Clinical Practice Guidelines for

Acute Nontraumatic RLQ Abdominal Pain and Tenderness and

Acute Appendicitis

Clinical Issue/Question

If paraclinical diagnostic procedure(s) is/are needed, what is/are the most cost-effective ones and how do we interpret the results?

Format of Guidelines Development

• Clinical Issue or Question
• Statement of Premises
• Operational Definition of Terms
• Evidence Appraisal Plan
• Search Methodology
• Search and Tracking Outcome
• Presentation of Primary Evidences
• Distillation of all Available Evidences to come out with recommendations or answers to the clinical issue/question
• Summary of Answers to Clinical Issue / Recommendations
• Future Research Issues / Questions
• References
• Quick Reference Guide or Algorithm

Clinical Scenario and Issue

In a non-immunocompromised patient of any age, any gender, communicative, coherent, with stable vital signs with acute nontraumatic right lower quadrant abdominal pain and tenderness,

With the primary clinical diagnosis being acute appendicitis but uncertain,

If paraclinical diagnostic procedure(s) is/are needed, what is/are the most cost-effective ones and how do we interpret the results?

Statement of Premises:

Objective of Paraclinical Diagnostic Procedure:

· To be more definite on the primary clinical diagnosis of acute appendicitis.

· Why the need to be more definite on the diagnosis?

· Uncertain clinical diagnosis or degree of certainty is below 90%

· Management will be altered if diagnosis is not acute appendicitis

Specifically, the concern is that a nonoperative treatment may be

instituted.

· A paraclinical diagnostic procedure is done only if it will significantly increase the pretest probability.

Given the following clinical parameters with their corresponding pretest probability,

Clinical Parameters	(+)LR	Pretest Probability
RLQ direct tenderness only		30%
Direct tenderness with guarding/rebound	~2	46%
Direct tenderness with rigidity	~4	63%
Definite, persistent, and increasing direct tenderness with guarding	~21	90%

a paraclinical diagnostic procedure is needed in the first three situations.

Goals in paraclinical diagnostic process:

· To select the most cost-effective paraclinical diagnostic procedure.

· To interprete the results appropriately to come up with a rational and accurate pretreatment diagnosis.

Operational Definition of Terms in the Issue/Question:

· Paraclinical diagnostic procedures – any procedure done after the initial history and physical examination with the objective of being more definite on the primary clinical diagnosis. It may be a repeat or repeated physical examination (active observation and monitoring), a laboratory examination, or any diagnostic procedure like a laparoscopy.

· Cost-effective procedure – the best after weighing the benefit-risk-cost-availability factors of paraclinical diagnostic options.

· Interpretation of results – to determine if appendicitis is present or not based on perceived result of the paraclinical diagnostic procedure correlated with the clinical findings or diagnosis.

Evidence Appraisal Plan:

End-points in answering the question:

· In patients with an uncertain clinical diagnosis of acute appendicitis, what is the most cost-effective paraclinical diagnostic procedure that will give a posttest probability of 90% or higher?

Clinical Parameters	Pretest Probability	Paraclinical Diagnostic Options	Posttest Probability
RLQ direct tenderness only	30%	???	90% or higher
Direct tenderness with guarding/rebound	46%	???	90% or higher
Direct tenderness with rigidity	63%	???	90% or higher

Statistical Formulas

LR(+) = sensitivity/ (1-specificity)

LR(-) = (1-sensitivity)/specificity

Prevalence = pretest probability

Pretest odds = prevalence/ (1-prevalence)

Posttest odds = pretest odds x LR

Posttest probability = posttest odds/(posttest odds+1)

Comparison of Various Options of Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Option	Benefit	Risk	Cost*	Availability
CBC
Urinalysis
Plain Abdominal X-ray
Barium Enema
Ultrasound
CT Scan
Laparoscopy
Active Observation and Monitoring

*Cost – stat basis (private setting) – most recent

Comparison of Various Options of Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Options	Diagnostic Parameter	Frequency of Finding Parameter	Sensitivity	Specificity	(+) LR
CBC
Urinalysis
Plain Abdominal X-ray
Barium Enema
Ultrasound
CT Scan
Laparoscopy
Active Observation and Monitoring

Posttest Probability of Various Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Diagnostic Parameters	Pretest Probability	Posttest Probability
Direct tenderness (DT)	30%
DT + leukocytosis
DT + leukocytosis + left shift
DT + normal urinalysis
DT + abnormal urinalysis
DT + appendicolith on plain abdominal x-ray
DT + nonfilling of appendix on barium enema
DT + dilated appendix on ultrasound
DT + dilated appendix on CT scan
DT + inflamed appendix on laparoscopy
DT + persistent DT
DT + progressive tenderness + guarding/rebound
DT + progressive tenderness + rigidity

Posttest Probability of Various Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Diagnostic Parameters	Pretest Probability	Posttest Probability
DT + Guarding/Rebound tenderness (DT/G/RT)	46%
DT/G/RT + leukocytosis
DT/G/RT + leukocytosis + left shift
DT/G/RT + normal urinalysis
DT/G/RT + abnormal urinalysis
DT/G/RT + appendicolith on plain abdominal x-ray
DT/G/RT + nonfilling of appendix on barium enema
DT/G/RT + dilated appendix on ultrasound
DT/G/RT + dilated appendix on CT scan
DT/G/RT + inflamed appendix on laparoscopy
DT/G/RT +persistence and progression of guarding/rebound
DT/G/RT with rigidity

Posttest Probability of Various Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Diagnostic Parameters	Pretest Probability	Posttest Probability
DT + Rigidity (DT/R)	63%
DT/R + leukocytosis
DT/R + leukocytosis + left shift
DT/R + normal urinalysis
DT/R + abnormal urinalysis
DT/R + appendicolith on plain abdominal x-ray
DT/R + nonfilling of appendix on barium enema
DT/R + dilated appendix on ultrasound
DT/R + dilated appendix on CT scan
DT/R + inflamed appendix on laparoscopy
DT/R+ persistence/progression of rigidity

Search Methodology:

Tracking:

Medline – for international journal publications

Herdin – for local journal publications

Internet using various search engines such as AltaVista, Infoseek, Lycos, etc.

Retrieval:

Retrieval of whole journal article was done through the various libraries of the Metro Manila medical schools, Department of Science and Technology (DOST), and acquaintances.

Appraisal (Inclusion Criteria):

· Focus of paper is on paraclinical diagnostic procedures for acute nontraumatic RLQ abdominal pain and acute appendicitis

· With gold standard (intraoperative findings, histopathological results, follow-up)

· More than 30 subjects

· With reliability data (sensitivity and specificity rates; likelihood ratios; odd ratios)

Search and Tracking Outcome:

· Total no. of papers and abstracts appraised: 500

· Level of evidences:

All were of Level III Evidence (case series)

Tracking and Retrieval Results:

Database Search engine	Search span	Search words	No. of titles	Relevant abstracts/papers
Medline	1966-1999 (August)	Ap + CBC	30	3
		Ap + Urinalysis	9	3
		Ap + Observation	91	5
		Ap + Plain Abdominal X-ray	4	1
		Ap + Barium Enema	79	5
		Ap + Ultrasound	121	10
		Ap + CT Scan	17	6
		Ap + Laparoscopy	88	2
Herdin		Appendicitis	107	0
AltaVista, Infoseek, Lycos, etc		Appendicitis	tntc	1

Presentation of Primary Evidences:

Comparison of Various Options of Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Option	Benefit	Risk	Cost*	Availability
CBC	Indirect evidence of inflammation Leukocytosis Shift to left	Puncture	P 234	Readily Available (RA)
Urinalysis	Indirect evidence Normal urinalysis	Nil	P 124	RA
Plain Abdominal X-ray	Indirect evidence Appendicolith	Radiation	P 430	RA
Barium Enema	Indirect evidence Nonfilling of appendix	Radiation	P 1950	Not RA (NRA)
Ultrasound	Indirect evidence Dilated appendix	Nil	P 3495 (F) P 2975 (M)	NRA
CT Scan	Indirect evidence Dilated appendix	Radiation	P 7000	NRA
Laparoscopy	Direct evidence Inflamed appendix	Invasive	P 20000	NRA
Active Observation and Monitoring	Indirect evidence Signs of RLQ peritonitis No alternative diagnosis	Nil	P 2000-3000 (2 days – MD’s fee with confine-ment cost)	RA

*Cost in Philippine Pesos – stat basis (private hospital) [1999]

Presentation of Primary Evidences

Comparison of Various Options of Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Options	Diagnostic Parameter	Frequency of Finding Parameter	Sensitivity	Specificity	(+) LR
CBC	Leukocytosis (TLC) Shift to left (NP)	66% (TLC+NP)	65.7	81.4	3.53 (TLC+NP)
Urinalysis	Abnormal urinalysis	All ages = 36-48% Children = 15-24%			NO DATA
Plain Abdominal X-ray	Appendicolith	10 - 24%	~24	~90	2.4 *
Barium Enema	Nonfilling of the appendix	All ages = 48% Children = 47%	83	96	20.75 **
Ultrasound	Dilated appendix	50-90%	55 (13-90) 83-89	95 (82-100) 92-96	11 *** 24-28
CT Scan	Dilated appendix	79-95%	90-100	93-97	14-30 ****
Laparos-copy	Inflamed Appendix	83%	~83	100	~83 *****
Active Observa-tion and Monitoring	Persistent, progressive, RLQ tenderness signifying peritonitis With no alternative diagnosis	100%	100%	95.33%	21

*Plain Abdominal x-ray - No concrete data on likelihood ratio

Calcified appendicoliths have a 90% predictability of acute

appendicitis in a patient with clinical findings suggesting acute appendicitis.

If 24% is used as the sensitivity rate and 90% as the specificity rate, then the positive likelihood ratio is 2.4.

** Barium enema - one study only.

***Ultrasound - multicenter study

Average (+) likelihood ratio: 20

****CT scan

Average (+) likelihood ratio: 22

*****No concrete data on laparoscopy:

- Grossly inflamed appendix is a gold standard for acute

appendicitis.

- If 83% of appendices can be seen on laparoscopy, if this is considered as the sensitivity rate, with a specificity rate of almost 100%, the positive likelihood ratio would, therefore, be 83.

Other notes:

- There are a lot of studies which do not show the frequencies of equivocal results.

See References

Summary of Paraclinical Diagnostic Procedures with LR of more than 10:

Options	Diagnostic Parameter	Frequency of finding parameter	(+) LR
Barium Enema	Nonfilling of the appendix	47-48%	20
Ultrasound	Dilated appendix	50-90%	20
CT Scan	Dilated appendix	79-95%	22
Laparoscopy	Inflamed appendix	83%	~83
Active Observation and Monitoring	Persistent, progressive, RLQ tenderness signifying peritonitis With no alternative diagnosis	100%	21

Posttest Probability of Various Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Diagnostic Parameters	Pretest Probability	Posttest Probability
Direct tenderness (DT)	30%
DT + leukocytosis		60%
DT + leukocytosis + left shift		60%
DT + normal urinalysis		30%
DT + abnormal urinalysis		30%
DT + appendicolith on plain abdominal x-ray		51%
DT + nonfilling of appendix on barium enema		90%
DT + dilated appendix on ultrasound		90%
DT + dilated appendix on CT scan		90%
DT + inflamed appendix on laparoscopy		100%
DT + progressive tenderness + guarding/rebound (+/-) rigidity		90%

Posttest Probability of Various Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Diagnostic Parameters	Pretest Probability	Posttest Probability
DT + Guarding/Rebound tenderness (DT/G/RT)	46%
DT/G/RT + leukocytosis		75%
DT/G/RT + leukocytosis + left shift		75%
DT/G/RT + normal urinalysis		46%
DT/G/RT + abnormal urinalysis		46%
DT/G/RT + appendicolith on plain abdominal x-ray		67%
DT/G/RT + nonfilling of appendix on barium enema		95%
DT/G/RT + dilated appendix on ultrasound		95%
DT/G/RT + dilated appendix on CT scan		95%
DT/G/RT + inflamed appendix on laparoscopy		100%
DT/G/RT +persistence and progression of guarding/rebound		95%
DT/G/RT with rigidity		95%

Posttest Probability of Various Paraclinical Diagnostic Procedures for Suspected Acute Appendicitis

Diagnostic Parameters	Pretest Probability	Posttest Probability
DT + Rigidity (DT/R)	63%
DT/R + leukocytosis		86%
DT/R + leukocytosis + left shift		86%
DT/R + normal urinalysis		63%
DT/R + abnormal urinalysis		63%
DT/R + appendicolith on plain abdominal x-ray		80%
DT/R + nonfilling of appendix on barium enema		97%
DT/R + dilated appendix on ultrasound		97%
DT/R + dilated appendix on CT scan		97%
DT/R + inflamed appendix on laparoscopy		100%
DT/R+ persistence/progression of rigidity		97%

Distillation of all available evidences to come out with recommendations or answers to the clinical issue/question:

In terms of benefit, the best paraclinical diagnostic procedures are those which give direct evidences; with a high frequency of finding the diagnostic parameter; and with a likelihood ratio of more than 10.

The paraclinical diagnostic procedure which fulfills these criteria is laparoscopy. It gives direct evidence (gross evidences of acute appendicitis – presence of purulent exudate, presence of phlegmon, gangrenous and perforated appendix). The frequency of finding the direct evidences is high (83% in one series which may be higher with other series). The direct evidences mentioned above constitute the gold standards of acute appendicitis. Thus, the specificity is near 100%. Putting 83% at the low level of sensitivity, the likelihood ratio will be a high 83.

However, with its invasiveness, extremely high cost, and it being not readily available in the Philippines, an alternative option will have to be considered.

The other paraclinical diagnostic procedures left after laparoscopy give indirect evidences.

Those that give a likelihood ratio of more than 10 are the following:

Barium enema

Ultrasound

CT scan

Active observation and monitoring

Comparing the factors of frequency of finding the diagnostic parameter, the benefit, risk, cost, and availability, (see table),

active observation and monitoring is the most cost-effective paraclinical diagnostic procedure.

Next is ultrasound.

Comparison of barium enema, ultrasound, CT scan, and active observation and monitoring in terms of benefit (frequency of finding diagnostic parameter and positive likelihood ratio) risk, cost, and availability

Options	Frequency Of finding parameter	(+) LR	Risk	Cost	Availability
Barium Enema	47-48%	20	Radiation	P 1950	NRA
Ultrasound	50-90%	20	Nil	P2975-3495	NRA
CT Scan	79-95%	22	Radiation	P 7000	NRA
Active Observation and Monitoring	100%	21	Nil	P 2000-3000	RA

Summary of Answer to Question or Recommendations:

In a non-immunocompromised patient of any age, any gender, communicative, coherent, with stable vital signs with acute nontraumatic right lower quadrant abdominal pain and tenderness,

With the primary clinical diagnosis being acute appendicitis,

If paraclinical diagnostic procedure(s) is/are needed, what is/are the most cost-effective ones and how do we interpret the results?

In patients suspected to have acute appendicitis,

if paraclinical diagnostic procedure(s) is/are needed,

the most cost-effective is active observation and monitoring.

The next most cost-effective is ultrasonography.

Diagnostic parameter in active observation and monitoring for acute appendicitis:

Definite, persistent, progressive, RLQ tenderness signifying peritonitis

(Direct tenderness with at least guarding or rigidity)

With no alternative diagnosis

Ultrasonographic diagnostic parameter for acute appendicitis (not excluding others):

Dilated appendix, more than 6 mm

Active Observation and Monitoring Scheme for Acute Appendicitis (Subject to Validation):

1^st Evaluation [Findings]	2^nd Evaluation [30 min after]	Action	3^rd Evaluation [Findings]	Action
*DT	(-) DT	Observe [30 min]	(-)DT	Dx:Not appendicitis
	DT	Observe [4-6 hrs]	DT	Observe – Follow DT track*
	DT+G/RT	Observe [30 min]	DT+G/RT	Dx:Appendicitis
	DT+RIGID	Observe [30 min]	DT+RIGID	Dx:Appendicitis
DT+G/RT	(-) DT	Observe [30 min]	(-)DT	Dx:Not appendicitis
	DT	Observe [30 min]	DT	Observe – Follow DT track*
	DT+G/RT	Dx:Appendicitis
	DT+RIGID	Dx:Appendicitis
DT+ RIGID	(-) DT	Observe [30 min]	(-)DT	Dx:Not appendicitis
	DT	Observe [30 min]	DT	Observe – Follow DT track*
	DT+G/RT	Observe [30 min]	DT+G/RT	Dx:Appendicitis
	DT+RIGID	Dx:Appendicitis

**During intervals of scheduled evaluation, patient is instructed to

report progression of symptoms so that evaluation can be done earlier.

Factors considered in formulating the scheme:

Safety - early vs delayed diagnosis

Reliability of evaluation findings (external and internal variations)

Efficiency

· Probability of detecting changes over time

· Utilization of emergency room resources

Experiences on when reliable signs of acute appendicitis usually occur

Indications for in-hospital observation and monitoring:

1. Strong suspicion for acute appendicitis (direct tenderness + guarding/rebound tenderness or rigidity in the absence of strong cues for an alternative diagnosis)

This is to facilitate treatment.

2. Convenience for the patient

If it is inconvenient for patient to come back for re-evaluation 4-6 hours after, then he/she may choose to be admitted to the hospital.

Note: For patients to be re-evaluated after 4-6 hours, they can be sent home with properly documented advices on what to monitor at home and when to come back.

End-points of observation and monitoring:

1. Until abdominal pain disappears.

2. Until diagnosis of acute appendicitis is quite certain.

3. Until a definite diagnosis other than acute appendicitis is obtained.

Future Research Issues/Questions Arising from Attempts to Answer Issue:

Validation of the active observation and monitoring scheme in terms

Cost-effectiveness

Length of stay in the emergency room

Whether patients can be observed at home

Negative appendectomy rate

Perforating appendectomy rate

References:

CBC as a Paraclinical Diagnostic Option

Lau WY, Ho YC, Chu W, Yeung C. Leukocyte count and neutrophil percentage in appendicectomy for suspected appendicitis. Aust N.Z. J. Surg 1989, 59, 395-398.

Title

Laboratory aid and ultrasonography in the diagnosis of appendicitis in children.

Author

Ko YS; Lin LH; Chen DF

Address

Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan, R.O.C.

Source

Chung Hua Min Kuo Hsiao Erh Ko I Hsueh Hui Tsa Chih, 1995 Nov, 36:6, 415-9

Title

White blood cell count is a poor predictor of severity of disease in the diagnosis of appendicitis.

Author

Coleman C; Thompson JE Jr; Bennion RS; Schmit PJ

Address

Olive View-University of California at Los Angeles Medical Center, Sylmar 91342, USA.

Source

Am Surg, 1998 Oct, 64:10, 983-5

Title

Urinalysis, ultrasound analysis, and renal dynamic scintigraphy in acute appendicitis.

Author

Puskar D; Bedalov G; Fridrih S; Vuckovic I; Banek T; Pasini J

Address

Department of Urology, New Hospital, Zagreb, Croatia.

Source

Urology, 1995 Jan, 45:1, 108-12

Abnormal urinalysis in appendicitis.

Author

Scott JH 3d; Amin M; Harty JI

Address

Source

J Urol, 1983 May, 129:5, 1015

Plain Abdominal X-ray as a Paraclinical Diagnostic Option

· 10% of finding abnormality (appendicolith) on plain abdominal x-ray

Craig S. Acute appendicitis. Online

http://www.emedicine.com/emerg/topic41.htm

· 14% of finding abnormality (appendicolith) on plain abdominal x-ray

Baker SR, Elkin M. Plain film approach to abdominal calcifications. Philadelphia, 1983, WB Saunders.

· Mollitt DL, Mitchum D, Tepas JJ III. Pediatric appendicitis: efficacy of laboratory and radiologic evaluation. South Med J 1988;81:1477-9.

(24% abnormal x-ray films of the abdomen)

· Calcified appendicoliths have a 90% predictability of acute appendicitis in a patient with clinical findings suggesting acute appendicitis.

Copeland EM, Long JM. Elective appendectomy for appendiceal calculus. Surg Gynecol Obstet 1970;130:439-442.

Barium Enema as a Paraclinical Diagnostic Option

Frequency of finding non-filling appendix

· Hatch EI Jr., Naffis D, Chandler NW. Pitfalls in the use of barium enema in early appendicitis in children. J Pediatr Surg 1981;16:3,309-12.

66 patients – 31/66

· Wild RE, Rutledge R, Herbst CA, Jr. The use of barium enema in the evaluation of patients with possible appendicitis. Am Surg 1985; 51:8, 474-6.

33 patients (all ages) – 16/33

Title

Barium enema in the diagnosis of acute appendicitis.

Author

el Ferzli G; Ozuner G; Davidson PG; Isenberg JS; Redmond P; Worth MH Jr

Address

Department of Surgery, Staten Island Hospital, New York 10305.

Source

Surg Gynecol Obstet, 1990 Jul, 171:1, 40-2

Ultrasound as a Paraclinical Diagnostic Option

Frequency of finding abnormality on ultrasound:

Ooms HWA, Koumans RKJ, Ho Kang You PJ, Puylaert JBCM. Ultrasonography in the diagnosis of acute appendicitis. Br J Surg 1991; 78:315-319.

Rioux M. Sonographic detection of the normal and abnormal appendix. AJR 1992;158:773-779.

Balthazar EJ, Birnbaum BA, Yee J, Megibow AJ, Roshkow J, Gray C. Acute appendicitis: CT and US correlation in 100 patients. Radiology 1994;190:31-5.

Title

Ultrasonography for diagnosis of acute appendicitis: results of a prospective multicenter trial.Acute Abdominal Pain Study Group.

Author

Franke C; Böhner H; Yang Q; Ohmann C; Röher HD

Address

Department of General and Trauma Surgery, Heinrich-Heine-Universit at, Moorenstrasse 5, 40225 Düsseldorf, Germany.

Source

World J Surg, 1999 Feb, 23:2, 141-6

Title

Influence of ultrasound on clinical decision making in acute appendicitis: a prospective study.

Author: Zielke A; Hasse C; Sitter H; Rothmund M

Address: Department of Surgery, Phillips-University of Marburg, Germany. Zielke@mailer.uni-marburg.de

Source: Eur J Surg, 1998 Mar, 164:3, 201-9

Title

Sonography of acute appendicitis in children: 7 years experience.

Author

Hahn HB; Hoepner FU; Kalle T; Macdonald EB; Prantl F; Spitzer IM; Faerber DR

Address

Department of Paediatric Radiology, Kinderklinik, Technischen UniversitÂat, Mâunchen, Germany.

Source

Pediatr Radiol, 1998 Mar, 28:3, 147-51

Title

“Surgical” ultrasound in suspected acute appendicitis.

Author

Zielke A; Hasse C; Sitter H; Kisker O; Rothmund M

Address

Department of General Surgery, Philipps-University of Marburg, Baldinger Strasse, PO-Box 100, 35043 Marburg, Germany.

Source

Surg Endosc, 1997 Apr, 11:4, 362-5

Title

Ultrasonography in suspected acute appendicitis in childhood-report of 1285 cases.

Author

Schulte B; Beyer D; Kaiser C; Horsch S; Wiater A

Address

Department of Diagnostic and Interventional Radiology, Academic Teaching Hospital Cologne-Porz, University of Cologne Medical School, Urbacher Weg 19, Krankenhaus Porz am Rhein, D-51149, Kâoln, Germany.

Source

Eur J Ultrasound, 1998 Dec, 8:3, 177-82

Title

Ultrasonography in patients with suspected acute appendicitis: a prospective study.

Author

Skaane P; Amland PF; Nordshus T; Solheim K

Address

Department of Radiology, Ullevaal University Hospital, Oslo, Norway.

Source

Br J Radiol, 1990 Oct, 63:754, 787-93

Title

Clinical validity of ultrasound in children with suspected appendicitis.

Author

Crady SK; Jones JS; Wyn T; Luttenton CR

Address

Emergency Medicine Residency Program, Butterworth Hospital, Grand Rapids.

Source

Ann Emerg Med, 1993 Jul, 22:7, 1125-9

Title

Ultrasonography in the diagnosis of acute appendicitis: a prospective study.

Author

Schwerk WB; Wichtrup B; Rothmund M; Rüschoff J

Address

Department of Internal Medicine, Philipps-University of Marburg, Federal Republic of Germany.

Source

Gastroenterology, 1989 Sep, 97:3, 630-9

Title

Ultrasonography as an adjunct in the diagnosis of acute appendicitis: a 4-year experience.

Author: Ramachandran P; Sivit CJ; Newman KD; Schwartz MZ

Address: Department of Surgery, Children’s National Medical Center, Washington, D.C. 20010, USA.

Source: J Pediatr Surg, 1996 Jan, 31:1, 164-7; discussion 167-9

CT Scan as a Paraclinical Diagnostic Option

Author	N	Sensitivity	Specificity	(+) LR
Lane, 1997	109	90	97	30
Rao, 1997	100	100	93	14.29
Balthazar, 1994	100	96	89	8.72
				Ave: 17.67

Balthazar EJ, Birnbaum BA, Yee J, Megibow AJ, Roshkow J, Gray C. Acute appendicitis: CT and US correlation in 100 patients. Radiology 1994;190:31-5.

Frequency of finding the parameter: 79 – 95%

Balthazar EJ, Megibow AJ, Hulnick D, Gordon RB, Naidich DP, Beranbaum ER. CT of Appendicitis. AJR 1986:147:705-710.

79% yield

Rao PM, Rhea JT, Novelline RA, Mostafavi AA, McCabe CJ. Effect of computed tomography of the appendix on treatment of patients and use of hospital resources. N Eng J Med 1998;338:141-146.

95% yield

Title

Unenhanced helical CT for suspected acute appendicitis.

Author

Lane MJ; Katz DS; Ross BA; Clautice Engle TL; Mindelzun RE; Jeffrey RB Jr

Address

Department of Radiology, Stanford University, School of Medicine, CA 94305-5105, USA.

Source

AJR Am J Roentgenol, 1997 Feb, 168:2, 405-9

Title

Helical CT technique for the diagnosis of appendicitis: prospective evaluation of a focused appendix CT examination [see comments]

Author

Rao PM; Rhea JT; Novelline RA; McCabe CJ; Lawrason JN; Berger DL; Sacknoff R

Address

Department of Radiology, Massachusetts General Hospital, Boston 02114, USA.

Source

Radiology, 1997 Jan, 202:1, 139-44

Laparoscopy as a Paraclinical Diagnostic Option

Olsen JB, Myren CJ, Haahr PE. Randomized study of the value of laparoscopy before appendicectomy. Br J Surg 1993; 80:922-923.

Yield: 83%

Title

Does laparoscopy reduce the incidence of unnecessary appendicectomies?

Author

Barrat C; Catheline JM; Rizk N; Champault GG

Address

UniversitÆe Paris XIII, EFR de MÆedecine de Bobigny, HÈopital Jean-Verdier, Bondy, France.

Source

Surg Laparosc Endosc, 1999 Jan, 9:1, 27-31

Observation as a Paraclinical Diagnostic Option

Author	N	Sensitivity (%)	Specificity (%)	(+) LR
Joson, 1990	505	100	95.33	21.38
Senbanjo, 1997	312	96	93	13.7

Title

Management of patients with equivocal signs of appendicitis.

Author

Senbanjo RO

Address

Department of Surgery, General Hospital, Sarat Abeidah, Kingdom of Saudi Arabia.

Source

J R Coll Surg Edinb, 1997 Apr, 42:2, 85-8

Abstract

Title

Probability of appendicitis before and after observation.

Author

Graff L; Radford MJ; Werne C

Address

Department of Medicine, University of Connecticut Health Center, Farmington.

Source

Ann Emerg Med, 1991 May, 20:5, 503-7

· Joson RO. Active observation in the evaluation of patients with possible acute appendicitis. Phil J Surg Special 1990; 45:3, 108-111

Quick Reference Guide or Algorithm:

In a non-immunocompromised patient of any age, any gender, communicative, coherent, with stable vital signs with acute nontraumatic right lower quadrant abdominal pain and tenderness,

With the primary clinical diagnosis being acute appendicitis but uncertain,

If paraclinical diagnostic procedure(s) is/are needed, what is/are the most cost-effective ones and how do we interpret the results?

In patients suspected to have acute appendicitis,

if paraclinical diagnostic procedure(s) is/are needed,

the most cost-effective is active observation and monitoring.