Eur J Surg Sci 2010;1(3):77-82
ORIGINAL ARTICLE
The Importance of Heel Drop Physical Examination Sign in Diagnosis of Acute Appendicitis Öner MENTEŞ1, Mehmet ERYILMAZ2, Kağan COŞKUN1, Ali HARLAK1, Tahir ÖZER1, Orhan KOZAK1 1 2
Department of General Surgery, Gulhane Military Medical Academy, Ankara, Turkey Department of Emergency Medicine, Gulhane Military Medical Academy, Ankara, Turkey
ABSTRACT Introduction: An accurate diagnosis of acute appendicitis is based on the patient’s history and the physical examination. We aimed to analyze whether or not the “heel-drop” (HD) test could be used as a diagnostic marker in acute appendicitis. Materials and Methods: Four hundred thirty patients were included in this study. The correlation of histopathological results was described in one, two or three variable parameters according to age, gender, presence of pain migration, white blood cell count (WBC), rebound tenderness, pain in the lower quadrant, muscular defense, and the HD test. Results: The mean age was 24.7 ± 8.3 (range: 15-74) years; 77.9% of the patients were male and 22.1% female. WBC > 11.950/ mm³ was shown to have the highest values regarding specificity (76.7%), positive predictive value (PPV, 95.1%), sensitivity (98.9%), negative predictive value (NPV, 42.9%) and accuracy (85.8%) regarding presence of pain in the right lower quadrant. Among single parameters, components with the highest odds ratios were assessed in combination with HD testing, while predictive characteristics of cases with two variable parameters were studied according to preoperative diagnostic criteria. The comparison of postoperative histopathological diagnoses with preoperative triad risk assessment demonstrated a statistically meaningful correlation regarding the results obtained from a triple variant analysis test. A positive HD test and a WBC > 11.950/mm³ and presence of pain in the right lower quadrant increased the probability of having appendicitis by 9.75-fold. Conclusion: We determined that a combination of findings (classical examination methods accompanied by a positive HD test, with the positive findings of the above-mentioned parameters) may be more significant in the diagnosis. Key words: Heel drop test, Acute appendicitis, Diagnosis, Physical examination
ÖZET
Fizik Muayenede Ayak Topuk Testinin Akut Apandisit Tanısındaki Önemi Giriş: Akut apandisitin doğru tanısında temeli hala hastanın anamnezi ve fizik muayene bulguları oluşturmaktadır. Bu çalışmada akut apandisitte “ayak-topuk” testinin pozitif olup olmamasının tanıda bir belirteç olup olamayacağını araştırmayı amaçladık. Materyal ve Metod: Çalışmaya 430 hasta dahil edildi. Histopatolojik sonuçlar ile ilişkili olarak yaş, cinsiyet, ağrı migrasyonunun varlığı, beyaz küre sayısı, rebound, sağ alt kadranda ağrı varlığı, defans ve “ayak-topuk” testi arasında birli, ikili ve üçlü değişkenlerin bir arada olması ile ilgili korelasyona bakıldı.
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The Importance of Heel Drop Physical Examination Sign in Diagnosis of Acute Appendicitis Bulgular: Hastaların ortalama yaşı 24.7±8.3 (15-74) yıl; %77.9 erkek ve %22.1 bayan olarak saptandı. Beyaz küre sayısı 11.950/ mm³’ün üzerinde olduğu zaman beraberinde sağ alt kadranda ağrı olması durumunda spesivitesi %76.7, pozitif prediktif değeri %95.1, sensitivitesi %98.9, negative prediktif değeri %42.9 ve doğruluk oranı %85.8 olarak bulundu. Tekli parametreler ele alındığı zaman “ayak-topuk testi” ile kombine edildiği zaman en yüksek odds-ratio oranları elde edildi, ameliyat öncesi tanıda parametrelerin ikili olan kombinasyonlarına da bakıldı. Ameliyat sonrasında histopatolojik tanı ile beraber bakıldığı zaman ameliyat öncesi değerlendirmede üçlü test parametreleri alındığı zaman istatistiksel olarak daha anlamlı sonuçlar elde edildi. Pozitif “ayak-topuk” testi, beyaz küre sayısının 11.950/mm³’ün üzerinde olması ve beraberinde sağ alt kadranda ağrı olması apandisit olasılığını 9.75 kat artırmaktaydı. Sonuç: Çalışma sonucunda bulguların kombine edilmesinin (klasik muayene bulguları ile pozitif “ayak-topuk” testinin birlikteliği, yukarıda sayılan pozitif parametrelerin olması) tanıda daha değerli olabileceği bulunmuştur. Anahtar kelimeler: Ayak topuk testi, Akut apandisit, Tanı, Fizik muayene
INTRODUCTION
Acute appendicitis is the most common abdominal surgical emergency that can affect individuals of all ages[1,2]. An accurate diagnosis of acute appendicitis can be established in the majority of patients based on the patient’s history and physical examination[3]. The majority of the studies focus on the probabilities related with mortality and morbidity, where diagnostic errors may occur. Delayed management of appendicitis is associated with prolonged hospitalization and an increased rate of perforation. Our aim in particular was to determine a means by which to avoid unnecessary surgical intervention in cases of right lower quadrant pain in the absence of histopathological appendicitis[4-6]. A Medline screening procedure, which was carried out according to the diagnosis of acute appendicitis, revealed no articles related with the use of “heeldrop” (HD) test as part of the physical examination. We failed to determine an adequate number of publications in the literature related with the degree to which the HD test can contribute in the diagnosis of acute appendicitis. Therefore, we aimed in this study to analyze the suitability of the HD test as a diagnostic marker in acute appendicitis. MATERIALS and METHODS
With institutional approval and after obtaining their written informed consents, 430 patients were included in this study between September 2005 and April 2006. Patients with abdominal pain and diagnosed with acute appendicitis by the participating surgeons were included in the study. The criteria for exclusion were: pediatric cases less than 15 years old, those with a previous abdominal surgery, and patients who were supervised due to abdominal pain.
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Clinical signs, laboratory values and pathology results were recorded for each patient. Correlations of age, gender, pain migration, white blood cell count (WBC) values, presence of rebound tenderness, presence of pain in the right lower quadrant, muscular defense, and presence of HD testing as single variable parameters are shown in Table 1. Sensitivity, specificity, negative and positive predictive values (NPV, PPV), diagnostic accuracy ratios, p values, odds ratios, and safety intervals were determined separately for each parameter. After this procedure, predictive characteristics according to preoperative diagnostic criteria, including the HD test, were determined for each criterion separately. Then, predictive characteristics were determined for each of the four parameters with the highest odds ratios, together with HD test positivity. Finally, predictive characteristics were determined for HD test positivity and the two parameters from the above-mentioned four with the highest odds ratios (Table 2). The receiver operating characteristic (ROC) curve analyses were ascertained according to single, double and triple parameters (Figure 1). Demographic findings were classified as percentage and median (minimum-maximum) values. The SPSS 15.0 (Chicago, IL, USA) package program was used for statistical assessment. The assessments of differences between groups were compared with chi-square test and MannWhitney U test. A p value < 0.05 was considered statistically significant. RESULTS
For this study, 430 patients [370 (86%) male; 60 (14%) female] were enrolled, and 370 (86%) of them had a final diagnosis of acute appendicitis (Table 1). The mean age of the patients was 24.7 ± 8.3 (range:
Eur J Surg Sci 2010;1(3):77-82
Menteş Ö, Eryılmaz M, Coşkun K, Harlak A, Özer T, Kozak O.
Table 1. Correlation between preoperative diagnostic parameters and histopathological diagnoses of patients Appendicitis
Normal Appendix
Total
n
%
n
%
n
%
Male Female Total
290 80 370
86.6 84.2 86
45 15 60
13.4 15.8 14
335 95 430
77.9 22.1 100
Presence None
285 85
89.1 77.3
35 25
10.9 22.7
320 110
74.4 25.6
> 11.950/mm³ ≤ 11.950/mm³
272 98
95.1 68.1
14 46
4.9 31.9
286 144
66.5 33.5
Presence None
319 51
87.6 77.3
45 15
12.4 22.7
364 66
84.7 15.3
Presence None
366 4
86.5 57.1
57 3
13.5 42.9
423 7
98.4 1.6
Presence None
133 237
85.8 86.2
22 38
14.2 13.8
155 275
36 64
Presence None
316 54
88.3 75
42 18
11.7 25
358 72
83.3 16.7
Gender
Pain Migration
White Blood Cells
Rebound Tenderness
Pain in the Right Lower Quadrant
Muscular Defense
Heel Drop
15-74) years. There were no significant differences between the two groups with respect to age and the histopathological results (p= 0.628) and gender and histopathological parameters (p= 0.558). However, a meaningful correlation was found between the presence of pain migration and histopathological results (p= 0.002). Histopathologically, the ratio of having appendicitis was found higher in cases with pain migration. In cases with a WBC > 10,000/mm³, a high correlation was found between the presence of a histopathological report and appendicitis (p= 0.0001). A meaningful correlation was determined statistically in the ratio between WBC ≥ 11.950/mm³ and the presence of appendicitis. Rebound tenderness, which was found to be positive in the physical examination of patients, was more common in cases with a higher ratio of risk for appendicitis (p= 0.025). In patients with pain in the right lower quadrant, the risk of appendicitis was higher; thus, this high ratio is not statistically significant (p= 0.06). Meanwhile, no significant difference was found in the risk of appendicitis between cases Eur J Surg Sci 2010;1(3):77-82
with and without muscular defense (p= 0.969). However, we determined a higher ratio of appendicitis risk in cases with a positive HD testing (p= 0.003) (Table 1). To determine the predictive characteristics of a histopathological diagnosis, sensitivity, specificity, NPV and PPV, ratios of accuracy, p value, odds ratio, and confidence intervals were calculated. Predictive characteristics were calculated according to pain migration, WBC, presence of rebound tenderness, pain in the right lower quadrant, muscular defense, and positive HD testing, in single, dual and triple parameter combinations (Table 2). We determined that WBC > 11.950/mm³ increased the probability of having appendicitis 9.12-fold (p= 0.0001), presence of pain in the right lower quadrant 4.82-fold (p= 0.06), pain during HD test 2.5-fold (p= 0.003), pain migration history 2.39-fold (p= 0.002), presence of rebound tenderness 2.08-fold (p= 0.025), and presence of muscular defense 0.969-fold (p= 0.914).
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The Importance of Heel Drop Physical Examination Sign in Diagnosis of Acute Appendicitis
Table 2. Predictive characteristics according to preoperative diagnostic criteria of patients 95% CI of OR Sensitivity
Specificity PPV NPV Accuracy
p
Odds Ratio
Highest Lowest
White Blood Cells ≥ 11.950/mm³
73.5
76.7
95.1
31.9
74
0
9.12
4.8
17.32
Presence of Pain in the Right Lower Quadrant
98.9
5
86.5
42.9
85.8
0.06
4.82
1.05
22.08
Heel Drop Test - Positive Finding
85.4
30
88.3
25
77.7
0.003
2.508
1.345
4.676
77
41.7
89.1
22.7
72.1
0.002
2.39
1.36
4.22
Presence of Rebound Tenderness
86.2
25
87.6
22.7
77.7
0.025
2.08
1.08
4.01
Presence of Muscular Defense
35.9
63.3
85.8
13.8
39.8
0.914
0.969
0.55
1.708
Heel Drop Test Positive + White Blood Cells ≥ 11.950/mm³
63.6
83.3
95.9
27
66.3
0
8.74
4.29
17.79
Heel Drop Test Positive + Presence of Pain in the Right Lower Quadrant
66.9
56.7
90.5
21.7
65.4
0
2.64
1.51
4.59
Heel Drop Test Positive + Presence of Pain Migration
84.3
31.7
88.4
24.7
77
0.003
2.51
1.36
4.61
Heel Drop Test Positive + Presence of Rebound Tenderness
75.2
45
89.4
22.7
71
0.001
2.48
1.42
4.35
Heel Drop Test Positivity Total together with White Blood (n= 243) Cells ≥ 11.950/mm³ and Male Pain in the Right Lower (n= 193) Quadrant Female (n= 50)
63.2
60
96.3
85
66.3
0
9.75
4.65
20.42
63.8
82.2
95.9
26.1
66.3
0
8.148
3.65
18.15
61.3
93.3
98
31.1
66.3
0
22.12
2.77
176.78
Presence of Pain Migration
PPV: Positive predictive value, NPV: Negative predictive value, CI: Confidence interval, OD: Odds ratio.
In singular parameters, cases with a WBC > 11.950/mm³ showed the highest specificity (76.7%) while the PPV (95.1%), highest NPV value (42.9%) and highest ratio of accuracy (85.8%) were shown in the presence of pain in the right lower quadrant. Predictive characteristics were further assessed according to preoperative diagnostic criteria in twovariable combinations: each of the four single parameters that demonstrated the highest odds ratios (WBC > 11.950/mm³, pain in the right lower quadrant, pain migration, and rebound tenderness) in combination with HD test positivity (Table 2). When the HD test was positive, the probability of having appendicitis was increased 8.74 times when
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WBC ≥ 11.950/mm³ (p= 0.0001); 2.64 times (p= 0.0001) when pain was present in the right lower quadrant; 2.51 times (p= 0.003) when pain migration was present, and 2.48 times (p= 0.001) when a rebound tenderness was present. Regarding dual-parameter combinations, the highest specificity (83.3%) and highest PPV value (95.9%) were determined for HD test positivity and WBC ≥ 11.950/mm³ (cut-off point) combination, while the highest sensitivity value (84.3%) was found for HD test positivity and presence of pain migration combination. When elements that are present at the highest odds ratios in dual parameters are assessed together with the HD testing parameters, the positivity of the
Eur J Surg Sci 2010;1(3):77-82
Menteş Ö, Eryılmaz M, Coşkun K, Harlak A, Özer T, Kozak O.
HD testing was investigated according to predictive characteristics related with a value of > 11.950/ mm³ and preoperative diagnostic criteria of cases in triple variable parameters that include presence of pain at the right lower quadrant. When preoperative triplerisk assessment markers were compared against postoperative histopathological diagnoses, we determined a statistically significant correlation in the results obtained from the triple variable analysis testing (p= 0.0001). Clinically, in cases with HD test positivity, WBC > 11.950/mm³ and presence of pain in the right lower quadrant, the probability of having appendicitis increased 9.75-fold (p= 0.0001). We determined that the PPV showed a tendency to increase to 96.3. In male and female patients with triple risk factors, the ratio of probability of having appendicitis was high (p= 0.0001), and the probability of having appendicitis increased 8.148-fold in males and 22.12-fold in females. DISCUSSION
Since acute appendicitis was first described, no acceptable physical examination finding that could be considered as a “gold standard” in defining the diagnosis has been identified. Doctor-patient interaction is influenced and modified by the developing imaging and laboratory technologies, and these often help doctors to obtain medical evidence easily, but they also tend to push physical examination findings to the background. The majority of surgeons may decide to operate on a patient based on suspected acute appendicitis with the single finding of rebound tenderness, which can be detected easily during the physical examination of the patient, even in the absence of a positive laboratory finding or radiological data. It is usually assumed that other methods are not as determinative as the presence of rebound tenderness. A literature review failed to demonstrate data that supports our opinion regarding HD testing, and we therefore designed this prospective study. From the epidemiological point of view, acute appendicitis is commonly seen in individuals between 20-29 years of age[7]. In the present study, the average age of the cases was compatible with the literature, at 24.7 ± 8.3 (range: 5-74) years. No cut-off value was determined that may reflect a statistical significance between the mean age of patients and histopathological diagnoses. The contribution of age as a risk factor was not found in the literature. The female/male ratio of cases in our study was Eur J Surg Sci 2010;1(3):77-82
1/16. In the literature, this ratio is reported as approximately two-fold higher in favor of females and in favor of males[8,9]. The high ratio of males in our study may be due to the fact that we serve a predominantly male military population. In our study, the presence of pain migration showed a meaningful correlation with WBC > 11.950/ mm³, presence of rebound tenderness in the right lower quadrant and histopathological results, but showed an insignificant correlation with pain in the right lower quadrant and the presence of right lower quadrant muscular defense. Tzanakis et al. found a significant correlation between all the above-mentioned parameters and postoperative histopathological diagnosis[10]. We determined that pain migration, pain in the right lower quadrant and rebound in the right lower quadrant increased the acute appendicitis risk 2.39-, 4.86-and 2.08-fold, respectively. Tzanakis et al. reported these ratios as 1.5-8.4-and 5.7-fold, respectively[10]. Tzanakis et al. considered a value equivalent to 12.000/mm³ as a cut-off value during the assessment of WBC, while the odds ratio was reported as 3.6-fold [10].According to Tepel et al., the cut-off value was considered as 10.000/mm³ and the odds ratio was determined as 6.71[11]. In our study, the cut-off value was determined as 11.950/mm³, while the odds ratio was found as 9.12. Tepel et al. reported the sensitivity, specificity and accuracy ratios in the diagnosis of acute appendicitis regarding WBC as 82%, 62% and 69%, respectively [11]. In our study, those values were determined as 73%, 76% and 74%, respectively. We believe our results are more determinative than the results obtained from the study carried out by Tepel et al. We conclude that a WBC equivalent to 11.950/mm³ could be more determinative for the diagnosis of acute appendicitis. To the best of our knowledge, there are no articles in the literature in which the HD test was considered as an assessment tool. Therefore, a study for comparison purposes was not available. We found that a positive HD test increased the probability of acute appendicitis 2.5-fold (p= 0.003) (Table 2). Components with the highest odds ratio value in single parameters were assessed together with the parameters of the HD test. When predictive characteristics were reviewed according to preoperative predictive diagnostic criteria of the cases, the ratio of an acute appendicitis risk was determined to be 8.74-
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The Importance of Heel Drop Physical Examination Sign in Diagnosis of Acute Appendicitis
fold higher in cases with WBC > 11.950/mm³, 2.64fold higher in cases with the presence of pain in the right lower quadrant, 2.51-fold higher in the presence of pain migration, and 2.48-fold higher in the presence of rebound tenderness. In cases in which HD testing was positive and WBC was > 11.950/mm³, a specificity of 83.3% and a PPV of 95.9% were calculated. In this study, we aimed to determine the impact of HD testing on the diagnosis of acute appendicitis, and we assessed together double or triple variable markers, which accompany the other, strongest markers. Regarding a single variable, a WBC > 11.950/mm³ demonstrated a 2.5- fold increase in the diagnosis of acute appendicitis. Presence of pain in the right lower quadrant, presence of pain migration and presence of rebound tenderness caused increases of 8.74-, 2.64-, 2.51- and 2.45-fold, respectively. For dual variables, cases with the highest marker characteristics and a WBC > 11.950/mm³ and presence of pain in the right lower quadrant led to an increase of almost 8.14- and 22.12-fold in males and females, respectively. CONCLUSION
Consequently, despite the developments in technology and the up-to-date clinical investigations, incorrect diagnosis is still a matter of concern in acute appendicitis. We conclude that when classical examination methods are accompanied by a positive HD test, with the positive findings of the above-mentioned parameters, this combination of findings may be more significant in the diagnosis of acute appendicitis. REFERENCES 1. Liu CD, McFadden DW. Acute abdomen and appendix. In: Greenfield LJ, Mulholland MW, Zelenock GB, Oldham KT, Lillemoe KD (eds). Surgery: scientific principles and practice. 3rd ed. Philadelphia: Lippincot-Raven; 1997. p. 1246-61.
J Clin Epidemiol 1998; 51: 859-65. 3. Fitz RH. Perforating inflammation of the vermiform appendix: with special reference to its early diagnosis and treatment. Am J Med Sci 1886; 92: 321-46. 4. Hale DA, Molloy M, Pearl RH. Appendectomy: a contemporary appraisal. Ann Surg 1997; 225: 252-61. 5. Orr RK, Porter D, Hartman D. Ultrasonography to evaluate adults for appendicitis: decision making based on meta-analysis and probabilistic reasoning. Acad Emerg Med 1995; 2: 644-50. 6. Wagner JM, McKinney P, Carpenter JL. Does this patient have appendicitis? JAMA 1996; 276: 1589-94. 7. Noudeh YJ, Sadigh N, Ahmadnia AY. Epidemiologic features, seasonal variations and false positive rate of acute appendicitis in Shahr-e-Rey, Tehran. Int J Surg 2007; 5: 95-8. 8. Al-Omran M, Mamdani MM, Mcleod RS. Epidemiologic features of acute appendicitis in Ontario, Canada. Can J Surg 2003; 46: 263-8. 9. Mungadi IA, Jabo BA, Agwu NP. A review of appendicectomy in Sokota, North-western Nigeria. Niger J Med 2004; 13: 240-3. 10. Tzanakis NE, Efstathiou SP, Danulidis K, Rallis GE, Tsioulos DI, Chatzivasiliou A, Peros G, Nikiteas NI. A new approach to accurate diagnosis of acute appendicitis. World J Surg 2005; 29: 1151-56. 11. Tepel J, Sommerfeld A, Klomp HJ, Eggert A, Kremer B. Prospective evaluation of diagnostic modalities in suspected acute appendicitis. Langenbecks Arch Surg 2004; 389: 219-24.
Address for Correspondence Öner MENTEŞ, MD Department of General Surgery Gulhane Military Medical Academy 06018 Etlik, Ankara-Turkey E-mail:
[email protected]
2. Blomqvist P, Ljung H, Nyren O, Ekbom A. Appendectomy in Sweden 1989-1993 assessed by the inpatient registry.
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Eur J Surg Sci 2010;1(3):77-82
