Evidence-based Clinical
Practice Guidelines for
Acute Nontraumatic RLQ
Abdominal Pain and Tenderness and
Acute Appendicitis
What
are reliable clinical parameters that we can use to make a confident primary
clinical diagnosis of acute appendicitis in patients presenting with an acute
nontraumatic right lower quadrant (RLQ) abdominal pain and tenderness?
In other words, with what clinical parameters can we
say that we are quite certain that the diagnosis is acute appendicitis that we
do not have to go through the paraclinical diagnostic process?
|
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, What are reliable clinical parameters that we can use to make a
confident primary clinical diagnosis of acute appendicitis in patients
presenting with an acute nontraumatic right lower quadrant (RLQ) abdominal
pain and tenderness? In other words, with what clinical
parameters can we say that we are quite certain that the diagnosis is acute
appendicitis that we do not have to go through the paraclinical diagnostic
process? |
|
In all patients presenting with an acute onset of
nontraumatic right lower quadrant (RLQ) abdominal pain, acute appendicitis is
always one of the considerations. The first cue for the diagnosis of acute appendicitis is RLQ abdominal pain. Not all patients with RLQ abdominal pain has acute appendicitis. Other causes consist of urinary tract infection, gastroenteritis, pelvic inflammatory disease, twisted ovarian cyst, to mention a few specific disorders. Majority of RLQ abdominal pain has a nonspecific cause, conveniently labeled as "nonspecific RLQ abdominal pain." There is a need for a structured evidence-based data collection and processing in order to improve the accuracy and efficiency of the clinical diagnosis of acute appendicitis. |
|
Operational Definition of Terms in
the Issue/Question: ·
Clinical parameters - data from history and physical examination
or symptoms (from history) and signs (from physical examination) · Acute appendicitis - appendicitis with localized right lower quadrant irritation or peritonitis · Patients - all ages; both genders · Reliability - more than 1 likelihood ratio or 90% or more post-test probability · Primary diagnosis - most likely diagnosis · Right lower quadrant abdominal pain - acute onset of RLQ abdominal pain, within 7 days |
|
End-points in answering the question: · Signs and symptoms that will lead to a primary diagnosis of 90% or more probability of acute appendicitis which may serve as the pretreatment diagnosis without going through paraclinical diagnostic procedures · Signs and symptoms that will lead to a primary diagnosis of less than 90% probability of acute appendicitis which may need paraclinical diagnostic procedures. Note: The end-point is clinical diagnosis, that is derived from history taking and performance of physical examination. This excludes all paraclinical diagnostic procedures except repeated history and physical examination. 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) |
|
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 on clinical diagnosis · With gold standard (intraoperative findings, histopathological results, follow-up) · More than 50 subjects · With reliability data (sensitivity and specificity rates; likelihood ratios; odd ratios) |
|
· Total no. of papers and abstracts appraised: At least 60 · Level of evidences: All were of Level III Evidence (case series)
Tracking and
Retrieval Results:
|
||||||||||||||||||||||||||||||||||||||||
|
Presentation
of Primary Evidences: Primary Evidence 1 There is only one
meta-analysis paper on the clinical diagnosis of acute appendicitis, that of
Wagner. ·
Wagner JM,
Mckinney WP, Carpenter JL. Does this patient have appendicitis? JAMA 1996;276:19, 1589-1594. ·
Wager JM. Summary of Clinical Examination Operating Characteristics for
Appendicitis. http://www.amaassn.org/scipubs/journals/archive/jama/vol_278/no_10/71076t1.htm ·
It is a
study of more than 4,000 patients with likelihood ratios for important
clinical diagnostic cues tabulated. ·
It is a
meta-analysis of 11 case series studies. ·
The search
strategy of Wagner yielded about 300 articles since 1966. The titles and
abstracts were reviewed and chosen if adequate detail of the outcomes and
aspects of the clinical examination allowed construction of 2x2 tables and
subsequent calculation of likelihood ratios.
Wagner, 1996
· RLQ pain (LR+=8.0) · Rigidity (LR+=4.0) · Migratory pain (LR+=3.1). These three findings can be recommended as cues for a clinical diagnosis of acute appendicitis. Guarding and Rebound Tenderness
· Guarding and rebound tenderness tests have a little more than one LR. · The LR+ of rebound tenderness varied too much to allow a statistical estimate of its effect (LR+= 1.1 to 6.30). · Difficult to make any conclusions as to which one is more reliable because of the wide range of positive LR for the former sign. Primary Evidence 1 (Wagner, 1996) Appraisal Notes: · Lot of case series studies on reliability of clinical parameters. All of them can be subsumed by the analysis of Wagner, unless there are studies that have as large a number of patient population as 4,000 and that have better study designs, in which the clinical parameters are well-defined and interrater variabilities are minimized. · Limitations of the Wagner's analysis: · Parameters evaluated are poorly defined in the text of studies · Single signs, rather than combined signs, are used Primary Evidence 2
Note: Papers on active observation
relied on clinical parameters. Thus, these papers could be good sources of
information for our question. We tried looking for specific description
of the clinical parameters used in the papers advocating observation in the
diagnosis of acute appendicitis. We were able to find only one
paper, that of Joson. Joson RO. Active observation in the evaluation of patients with possible acute
appendicitis. Phil J Surg Special 1990;
45:3, 108-111 (Age: 7-71; Sex: 262 - females; 242 - males) ·
Signs of
peritoneal irritation: definite, persistent, and increasing direct RLQ tenderness with
guarding* *rebound tenderness was not elicited anymore because of the author’s
belief that rebound tenderness is nonspecific; eliciting it is cruelty; and
that rebound tenderness is assumed to be present when a patient is guarding his/her RLQ because of pain.
|
|
We thought of starting the analysis with the
pathophysiology of acute appendicitis and enumerating the expected symptoms
and abdominal signs. Then, we tried differentiating acute appendicitis from
other common specific causes of acute nontraumatic RLQ abdominal pain. Then,
we tried coming out with an approach in the clinical evaluation of patients
with acute RLQ abdominal pain with acute appendicitis as one of the considerations. Pathophysiology and Expected Symptoms and Abdominal Signs of the Common
Specific Causes of Acute
Nontraumatic RLQ Abdominal Pain (For Pattern
Recognition Use) 1. Acute Appendicitis
Note 1: The more full-blown or advanced in the pathophysiology of the disease is, the more reliable are the clinical parameters present. For example, rigidity will be most likely present during the severe inflammatory phase and direct tenderness without rigidity in the earlier phases. Rigidity as a clinical parameter to suspect acute appendicitis will, therefore,be expected to be more reliable than direct tenderness without rigidity. Differentiating Acute
Appendicitis from the Other More Common Specific Causes of Acute Nontraumatic
RLQ Abdominal Pain
Note 2: The reliability of the clinical parameters for acute appendicitis present during the time of evaluation will be dependent primarily on the phase of the pathophysiology of the disease the patient is in. From the above table, after RLQ direct tenderness, one can use presence or absence of RLQ peritonitis as the parameter to group the various disorders into 2 categories: RLQ direct tenderness with RLQ peritonitis Acute appendicitis Pelvic inflammatory disease Ruptured right ectopic pregnancy Twisted right ovarian tumor RLQ direct tenderness without RLQ peritonitis Acute gastroenteritis Urinary tract infection Ureteral stone For the category with RLQ peritonitis, one can use specific cues to suspect a particular disease outside of acute appendicitis, example, purulent vaginal discharge for pelvic inflammatory disease; pregnant suspect and vaginal bleeding, for ectopic pregnancy; an intraabdominal mass, for twisted ovarian tumor. In the presence of RLQ peritonitis, acute appendicitis should be the primary suspect or diagnosis if there are no cues to suggest another disease. If there are, the other disease is the primary suspect and acute appendicitis is just a differential or secondary diagnosis. What constitute signs of RLQ
peritonitis?
How reliable are
the following possible RLQ signs in patients with acute appendicitis? ·
Direct
tenderness only ·
Direct
tenderness with rebound tenderness ·
Direct
tenderness with guarding ·
Direct tenderness with
rigidity ·
Definite, persistent,
and increasing direct tenderness with guarding Based on evidences (Wagner and Joson) and our computations, Premise: Direct tenderness has
a Pretest Probability at 30% *
*Wagner (see also References) |
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, What are reliable clinical parameters that we can use to make a
confident primary clinical diagnosis of acute appendicitis in patients
presenting with an acute nontraumatic right lower quadrant (RLQ) abdominal
pain and tenderness? In other words, with what clinical
parameters can we say that we are quite certain that the diagnosis is acute
appendicitis that we do not have to go through the paraclinical diagnostic
process? The reliable clinical parameters that we can use for making a primary
clinical diagnosis of acute appendicitis (of 90% or more probability) in
patients with acute RLQ abdominal pain consist of the following:
RLQ abdominal pain and tenderness with signs of
peritoneal irritation No alternative diagnosis of the RLQ signs of
peritoneal irritation RLQ Signs of Peritoneal Irritation: ·
Definite (persistent progressive) direct tenderness with at least
guarding ·
Rigidity |
|
Future Research Issues/Questions Arising from Attempts to Answer Issue: RLQ rebound tenderness and guarding, which is a more reliable cue for
peritoneal irritation?
|
|
· Wagner JM, Mckinney WP, Carpenter JL. Does this patient have appendicitis? JAMA 1996;276:19, 1589-1594. Pretest probability of acute appendicitis is 12 to 26% · Wager JM. Summary of Clinical Examination Operating Characteristics for Appendicitis. http://www.ama-assn.org/sci-pubs/journals/archive/jama/vol_278/no_10/71076t1.htm · Leopando ZE, Ulanday JB. Acute appendicitis: Toward a better diagnosis. Fil Fam Phy 1980;13:3,1-5. · Hale DA, Molloy M, Pearl RH, Schutt DC, Jaques DP. Appendectomy: A contemporary appraisal. Ann Surg 1997; 225:3, 253-61. · Hale DA, Jaques DP, Molloy M, Pearl RH, Schutt DC, dAvis JC. Appendectomy. Improving care through quality improvement. Arch Surg 1997; 132:2, 153-7. · Condon RE, Relford GL. Appendicitis. In Sabiston DC, editor. Textbook of Surgery: the biological basis of modern surgical practice. Philadelphia: WB Saunders Co, 1991:884-98. Classic pain sequence may be elicited in only 55% of patients with appendicitis. · Poole GV. Appendicitis. The diagnostic challenge continues. Am Surg 1988;54:609-612. Classic presentation is seen in less than half. · 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, What are reliable clinical parameters that we can use to make a
confident primary clinical diagnosis of acute appendicitis in patients
presenting with an acute nontraumatic right lower quadrant (RLQ) abdominal
pain and tenderness? In other words, with what clinical
parameters can we say that we are quite certain that the diagnosis is acute appendicitis
that we do not have to go through the paraclinical diagnostic process? The reliable clinical parameters that we can use for making a primary
clinical diagnosis of acute appendicitis (of 90% or more probability) in
patients with acute RLQ abdominal pain consist of the following:
RLQ abdominal pain and tenderness with signs of
peritoneal irritation No alternative diagnosis of the RLQ signs of
peritoneal irritation RLQ Signs of Peritoneal Irritation: ·
Definite (persistent progressive) direct tenderness with at least
guarding ·
Rigidity |