Article, Surgery

The utility of the speed bump sign for diagnosing acute appendicitis

a b s t r a c t

Background: Acute appendicitis is the most common abdominal complaint in the emergency department. This study was made in order to determine whether there is any evidence to support the practice of inquiring about pain over speed bumps in patient suspected to have acute appendicitis and to discover its Predictive power as a diagnostic sign.

Method: A prospective study was conducted in the emergency department of Al Ain Hospital over one year. A convenient sample of 100 consecutive adult patients over the age of 15 years who presented with an abdominal pain and symptoms suggestive of acute appendicitis were recruited over the study period. They all underwent questionnaire of whether they had pain, or their pain increased while they travelled over speed bumps.

Results: The study shows that 80 of the 90 participants were “speed bump positive.” Eighty-five had a confirmed diagnosis of appendicitis, 77 of whom had worsened pain over speed bumps, giving a sensitivity of 90.5% and a specificity of 40%. The positive predictive value was 96.25% and the negative predictive value was 20%. The like- lihood ratios were 1.5 for a positive test result and 0.23 for a negative result.

Conclusion: The pain over speed bump can be considered as a significant “rule out” criterion of appendicitis due to the high sensitivity observed in this study. However, with its low specificity, many patients with this sign would not undoubtedly have appendicitis, meaning it is a poor “rule-in” test.

(C) 2019


Speed bumps are used commonly in streets as traffic soothing mea- sures in order to lower vehicles’ velocity. These measures have been found to decrease different kinds of injuries by a 70% in child pedes- trians in many countries, and they could be an encouraging intervention to reduce the frequency of road traffic morbidity and mortality in gen- eral. However, speed bumps might be especially beneficial in acute ap- pendicitis diagnosis [1].

Acute appendicitis is considered the commonest abdominal ailment in the emergency department that require emergency surgery. How- ever, it is usually challenging to diagnose, and it is often unclear to de- cide whether to observe, operate, or to do further work-up on the patient [2].

The Presenting complaints are usually atypical, and it is challenging to diagnose due to overlapping of symptoms with other problems espe- cially when physical and Blood results are nearly missing in nearly 55% of the cases [3] and [4]. Appendicitis usually starts with the uncertain central abdominal pain that is usually dull followed by different gastro

* Corresponding author at: Al Ain Hospital, Shakboot Bin Sultan Street, Al Ain, P.O. Box 1006, United Arab Emirates.

E-mail address: [email protected] (M.M. Eid).

intestinal symptoms such as anorexia, nausea, and vomiting. Often later the pain migrates to right iliac fossa. In most presentations the pa- tient reports no similar previous pain. However, the presentation may be widely differing from patient to patient [5].

A keystone to mitigate the rate of negative appendectomy is to en- hance the diagnostic process, and before the use of CT scans, doctors depended on physical examinations, with the use of some laboratory parameters [6].

A couple or more scores have been found to help clinicians in the di- agnosis. The two mostly used are Alvarado and AIR (Appendicitis In- flammatory Response) or (Andersson) score, they apparently can increase the rate of accurate diagnosis, and so will decrease need for in- vasive and expensive procedures [7,8].

Patients having appendicitis have reported many times that they complained of increasing abdominal pain when their cars travelled over speed bumps. This study was made in order to determine whether there is any evidence to support the practice of inquiring about pain over speed bumps and to discover its potential as an aid in the diagnosis. It is worth mentioning for example that in our hospital, the local guide- lines dictate the surgeons take the patient to operating room only after radiographically diagnosed with appendicitis, so we are using a lot of imaging whether CT scans and/or Ultrasound to make definitive diagno- sis. In doing this study we are trying to limit the use of invasive imaging and to rely more upon clinical examination findings.

0735-6757/(C) 2019

1552 M.M. Eid, M. Al-Kaisy / American Journal of Emergency Medicine 38 (2020) 15511553


Design and settings

This is a prospective study, which was done in (name deleted to

Table 2

Diagnostic Imaging results.

Diagnostic imaging utilised Operated patients (total of 90)

Non- operated patients

(total of 10)

maintain the integrity of the Review process) in (name deleted to main-


Appendicitis 40 5

tain the integrity of the review process). The city of (name deleted to maintain the integrity of the review process) with a population reaching


Appendix not visualised

20 3

nearly 800,000 people is the 4th largest city in (name deleted to main- tain the integrity of the review process), where the majority of roads are smooth and well paved, equipped with many types of speed bumps in different shapes and designs.

abdominal CT scan (with or without

contrast) revealed acute appendicitis

2.4. Statistical methods

30 2

Sample and sampling technique

Patients aged 15 and above, who presented to our emergency depart- ment with abdominal pain and features suggestive of acute appendicitis as the triage chief complaint were included in our study, they were re- cruited over 12 months’ period from January 2018 to January 2019. Any patient less than 15 years, with abdominal pain elsewhere were excluded.

Variables and measurements

Patients underwent a full Abdominal examination and were asked a direct question of whether they had pain, or their pain increased while they travelled over speed bumps during their journey to the hospital whether they travelled by car or ambulance. The patients were asked during their stay in the department, before any decision of disposition was made. Clinicians enrolled the patients in the study and asked the questions, they were blinded to the study purpose.

We labelled the patient who experienced pain, or their pain was in- creased while travelling over bumps as (speed bump sign positive), and those who did not as (speed bump sign negative). All enrolled patients undergone imaging whether Ultrasound or CT scan, and the results were compared with the findings of history and physical examination. We did a follow up of those patients through their journey in the hospital to determine the outcome and we obtained the histology re- port for those patients who underwent surgery. We used the histology report of acute appendicitis as our reference standard. Positive and neg- ative histology report were collected, and we assumed the patient who their symptoms were resolved without surgery as negative diagnosis

and made sure they were fine by a telephone call within 2 weeks.

Table 1

Patient characteristics.

We calculated the sensitivity, specificity, positive and negative pre- dictive value, positive and negative likelihood ratio for the speed bump sign, and for other parameters of Alvarado score such as rebound tenderness and white blood cell count, and we compared all results to- gether to measure the accuracy of speed bump sign.


One hundred participants were enrolled in our study. The mean age was 34 (15-53) years. Patients characteristics are showed in (Table 1). All patients had travelled over speed bumps. Eighty-five made it to the emergency department by a private car and fifteen came in through am- bulance. Ninety patients were conveyed to operation room for pre- sumed appendicitis. Ten participants were not operated due to refusal of operation or because they preferred to look for a second opinion in different facility that cannot be followed.

All patients were investigated by imaging modalities including ab- dominal US and CT scan as shown in (Table 2). The diagnosis of appen- dicitis established histologically in 85 out of 90, which gave a false positive appendectomy estimate of 6%.

Our study shows that 80 of the 90 participants were “speed bump sign positive.” Eighty-five had a proved appendicitis, 77 of those had ag- gravated pain over speed bumps, making the sign sensitive in 90.5% and specific in 40%.

The likelihood ratios for positive and negative tests results were 96.25% and 0.23 respectively. While the positive predictive value was 96.25% and the negative predictive value was 20% (Tables 3 & 4).

The speed bump sign was compared to Alvarado score as a com- posed score and results are displayed in (Table 5).

Three patients who were “speed bump positive” but they were not diagnosed with appendicitis had different important abdominal prob- lems, such as a PID, ruptured ovarian cyst, or UTI (Table 6).

Patient character Acute appendicitis (+)

(total of 90)

Acute appendicitis (-)

(total of 5)

Non operated patients (total of 10)


Gender Male 63 2 8

Female 20 3 2

Ethnicity/race Arab 28 1 2

Asian 39 2 6

Black 10 0 1

White 8 2 1

The above results clearly ascertain that increasing pain when passing over speed bumps definitely increases possibility of appendicitis; on the other hand, lack of the mentioned sign was linked to a noticed decre- ment in possibility of appendicitis. Despite the fact that specificity is somewhat low, but compared with other diagnostic signs of acute ap-


Abdominal pain 25 1 3

pendicitis, worsening of pain over speed bumps was more sensitive


Abdominal pain with Nausea and/or vomiting Abdominal pain with diarrhoea Abdominal pain with fever

40 2 5

12 1 0

8 1 2

and had more significant negative likelihood than all other signs.

Table 3

Illustrates pain over speed bumps in association with acute appendicitis.

Comorbidities Nill 59 4 10

diabetes 12 1 0









Anaemia (G6PD













Pain over speed bumps Appendicitis positive Appendicitis negative Total

M.M. Eid, M. Al-Kaisy / American Journal of Emergency Medicine 38 (2020) 15511553 1553

Table 4

Shows pain over speed bumps with 95% CI in contrast to different clinical factors used for acute appendicitis diagnosis.


Sensitivity %

Specificity %

Positive predictive value %

Negative predictive value %

Positive likelihood ratio

Negative likelihood ratio

Pain over speed pump







Migratory pain














nausea or vomiting







Rebound tenderness







Table 5

Speed bump sign compare to the Alvarado score as a composite score.

Speed bump sign in relation to Acute Appendicitis Alvarado score as a

composite score

Strengths and limitations

Strengths of this study include the collection of information from the patients in a systematic approach and getting the data early at the time of admission to the emergency department and then later in during

Positive Speed bump sign with positive Acute Appendicitis

Positive Speed bump sign with negative Acute Appendicitis

Negative Speed bump sign with positive Acute Appendicitis

Negative Speed bump sign with negative Acute Appendicitis





their stay in hospital. It is worth mentioning that according to the hos- pital and surgical institute policy in our hospital, they will not take the patient to operation room most of the time unless appendicitis is con- firmed by imaging (whether ultrasound or CT scan), and this led to in- crease in number of positive appendicitis among total recruited patients in the study.


Table 6

Description of patient who is speed bump sign positive and negative appendicitis.

It can be said the “positive speed bump sign” has a higher sensitivity than all the other historical elements that we traditionally use to assess a patient’s pre-test probability of appendicitis–which is supported by

Patient with speed bump positive with negative appendicitis


our results. Due to the high sensitivity observed in this study, so it can be considered as a beneficial tool to exclude acute appendicitis and

Patient No. 1 Pelvic inflammatory disease

Patient No. 2 Ruptured Ovarian Cyst

Patient No. 3 Urinary Tract Infection

In addition, some of the participants in the study who were “speed bump sign positive” but were not diagnosed with appendicitis were ac- tually having different other diagnoses, including but not limited to rup- tured ovarian cyst or pelvic inflammatory disease.

The aggravation of pain when passing over those bumps is probably due to irritation of the parietal layer of peritoneum by stretching or moving like in rebound tenderness.

In a similar study done in UK in which they assessed pain when trav- elling on speed bumps in diagnosis of appendicitis, the sensitivity of speed bump sign was highest than all parameters, while the negative likelihood ratio was the least favourable in diagnosis than all parameters including rebound tenderness [1].

Andersson have done a meta-analysis of the diagnostic power of dif- ferent clinical features of appendicitis, the “negative likelihood ratio” of (0.23) for pain over speed bumps, exceeded not only other clinical var- iables in our study as shown in Table 2, but also those in Andersson’s meta-analysis including migratory pain (0.52), nausea and vomiting (0.72), and rebound tenderness (0.39) [3].

Another study which assesses the presence of peritonism in appen- dicitis found that pain on going over a bump in road (named cat’s eye sign) had 82% sensitivity and 52% specificity which was more than all other parameters recruited in the study as vomiting, anorexia, migra- tory pain and rebound tenderness [9].

other crucial Abdominal diagnoses. However, with its low specificity, many patients with this sign would not undoubtedly have appendicitis, meaning it is a poor “rule-in” test. Still, there is a potential for this sign to be integrated into the collection of clinical signs of acute appendicitis. Most of our patient had been assessed by physician who made a pre- sumed diagnosis of appendicitis. Thus, the pre-test probability is fairly high; the speed bump test might also be useful in assessment of all other types of abdominal pain, not just when appendicitis is suspected. Although being “speed bump sign negative” may provide tranquil- lity for the diagnosis of appendicitis, being “speed bump sign positive”

does not ascertain a diagnosis of appendicitis.


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