Original Article

Alvarado score : an admission criterion in patients with right iliac fossa pain

M.Y.P. Chan
C. Tan
M.T. Chiu 
Y.Y. Ng 
Department of Surgery and Emergency Department, Alexandra Hospital, Singapore

Correspondence to: Dr M.Y.P Chan, Department of Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433

Introduction Methods and materials  Results

Discussion Conclusion References

Keywords : Alvarado score, appendicitis, admission criterion
Surg J R Coll Surg Edinb Irel., 1 February 2003, 39-41

Appendicitis is an important differential diagnosis in patients with right iliac fossa pain. The diagnosis in patients with equivocal signs can be difficult. Many patients with suspected appendicitis are admitted for observation. We studied the Alvarado scores of 175 patients who presented to the emergency department with right iliac fossa pain and found that patients with scores of 4 or less did not have appendicitis. We also present an algorithm incorporating the Alvarado score for patients with suspected appendicitis

INTRODUCTION
Appendicitis is a common surgical emergency that primary healthcare providers have to consider when patients present with right iliac fossa pain. Patients with equivocal signs can present a diagnostic challenge and are very often admitted to the surgical department for observation.

In a previous study, we have found that patients with a low Alvarado score (less than 5) did not have appendicitis.¹ Owen et al (1992) reported that there was no perforated appendicitis in patients with a score of less than 6 and suggested the use of the score by general practitioners.² Thus, we decided to design this study with the aim of investigating whether the Alvarado score can be used by emergency room doctors as a criteria for admission to hospital.

METHODS AND MATERIALS
This is a prospective study comprising consecutive patients who attended the emergency department with suspected appendicitis during the months June to October 1999.

The Alvarado score is based on three symptoms, three signs and two laboratory findings, as shown in Table 1. Patients were scored in the emergency department and if they were admitted, had a second scoring in the ward. The decision for admission and surgery was made independent of the score. Diagnosis of patients who underwent appendicectomy was confirmed by both operative findings and histology. Patients who were not admitted to the hospital were told to attend the clinic the next working day. In our study, normal appendicectomy was defined when a non-inflamed appendix was removed at surgery.

RESULTS
The study had 175 patients, comprising of 130 males and 45 females with ages ranging from 8 to 73 years (mean 30 years). The majority of the patients (106/175) were referred from another doctor with suspected appendicitis. A total of 149 patients were admitted to the hospital for observation and two patients had surgery for other conditions. Eighty-nine patients had surgery with the intention to treat appendicitis and 14 patients did not have appendicitis (Table 2). The normal appendicectomy rate was 13%, as two patients had a diagnostic laparoscopy and did not have their appendices removed.

At the emergency department, there were 56 patients with a score of 4 or less and 34 patients were admitted for observation. There was no appendicitis in this group of patients. Twenty-six patients were discharged from the emergency department and 23 attended the outpatient clinic the next day and were found to be well and not requiring further treatment. Three patients who did not attend their appointments had telephone interviews one month after and all had remained asymptomatic.

Of the patients with appendicitis, 41% (31/75) had higher scores in the ward, when compared with the initial score at the emergency department. This was consistent with the commonly held view that appendicitis is a progressive disease and signs and symptoms change with time.

DISCUSSION
Appendicitis still poses a diagnostic challenge and many methods have been investigated to try to reduce the removal of a normal appendix without increasing the perforation rate. Radiological methods such as ultrasonography and computed tomography, as well as laparoscopy are all methods that have been investigated previously.^3-5 Many diagnostic scores have been advocated but most are complex and difficult to implement in a clinical situation.⁶ The Alvarado score, first described in 1988, is a simple scoring system that can be instituted easily in the outpatient setting.⁷ In a previous study, we found that the Alvarado score was most accurate only at the two extremes of the score. Good clinical acumen remains the mainstay of correct diagnosis of appendicitis.^8-9

General practitioners and emergency physicians face a difficult problem when presented with a patient with right iliac fossa pain with equivocal signs. The decision to admit or discharge these patients is not always straightforward. This may be compounded by the relative lack of surgical experience of many junior doctors who may need to make this decision at the emergency department. Our previous study has found that no patient with a score below 5 had appendicitis, which is similar to results from other investigators.² We have designed this study to evaluate the score as an objective criterion for inpatient admission into a surgical unit.

Our results show that none of the patients with a score of 4 or less had appendicitis. If this was used as the admission criteria, 34 patients who were admitted could have been observed as outpatients. Admission rate would have been reduced by 20%, as four patients with a score of 5 who were discharged from the emergency department would instead be admitted. We also found that a significant number of patients with appendicitis had their score increased after admission to the wards. Therefore, patients should be advised to return should the symptoms become worse. It is also prudent to ask the patients to attend the clinics within 24 hours for reassessment although our study shows that none of the patients in this group eventually required appendicectomy. It is also important to emphasise that the scoring may not be accurate in patients who are unable to give a proper history, such as the very young or those with communication problems.⁷

CONCLUSION
The Alvarado score can be used as an objective criterion in selecting patients for admission with suspected appendicitis (Figure 1). It is important to advise patients to return for review 24 hours later or if symptoms worsen. Patients who live alone and do not have family support or are unwilling to be observed at home could be admitted as is our current practice.

Figure 1: Algorithm for using the Alvarado score as an objective criteria for admission to the surgical department

REFERENCES
1. Chan MY, Teo BS, Ng BL. The Alvarado score and acute appendicitis. Ann Acad Med Sing 2001; 30: 510-12
2. Owen TD, Williams H, Stiff G, Jenkinson LR, Rees BI. Evaluation of Alvarado score in acute appendicitis. J R Soc Med 1992; 85:87-89
3. Rao PM, Boland GW. Imaging of acute right lower abdominal quadrant pain. Clin Radiol 1998; 53:639-49
4. Jain KA, Quam JP, Ablin DS, Gerscovich EO, Shelton DK. Imaging findings in patients with right-lower quadrant pain: alternative diagnosis to appendicitis. J Comput Assist Tomogr 1997; 21:693-98
5. Moberg AC, Ahlberg G, Leijonmarck CE, Montgomery A, Reiertsen O, Rosseland AR, et al. Diagnostic laparoscopy in 1043 patients with suspected acute appendicitis. Eur J Surg 1998; 164:833-40
6. Ohmann C, Yang Q, Franke C. Diagnostic scores for acute appendicitis. Abdominal Pain Study Group. Eur J Surg 1995; 161:273-81
7. Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med 1986; 15: 557-64
8. Izbicki JR, Knoefel WT, Wilker DK, Mandelkow HK, Muller K, Siebeck M et al. Accurate diagnosis of acute appendicitis: a retrospective and prospective analysis of 686 patients. Eur J Surg 1992; 158: 227-31
9. Wilcox RT, Williams LW. Have the evaluation and treatment of acute appendicitis changed with new technology? Surg Clinics of North Am 1997; 77: 1355-170

Copyright: 7 January 2003

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