Objective
To study the relationship between hyperbilirubinemia and acute appendicitis and to evaluate its credibility as a diagnostic marker for acute appendicitis and to evaluate whether elevated serum total bilirubin levels have a predictive potential for the diagnosis of complicated appendicitis

Background
In acute appendicitis occurs through bacterial invasion in appendix leads to transmigration of bacteria and release of TNF-alpha, IL6 and cytokines. These reach the liver through the superior mesenteric vein and may produce inflammation or dysfunction of the liver either directly or indirectly by altering hepatic blood flow with rising of total serum bilirubin [1].

Methods
This is a prospective cohort study including Ninety-four (94) of adult patients have right iliac fossa pain being present at the Emergency Department (ED) at Suez Canal University Hospital from the 15th of May 2015 to the 14th of May 2016. All 94 patients undergo total serum bilirubin measuring and post-operative histopathological examination of the removed appendix.

Results
In this study population of 94 patients and found that thirtysix male patient (38 %) and fifty-eight female patient (62 %), 81 patients (86.2%) were diagnosed as acute appendicitis while 13 patients (13.8%) were normal post-operatively by histopathological reports. Amongst the patients diagnosed with Acute appendicitis post-operatively, 57 patients (70.4%) were found to have elevated serum total bilirubin (>1.2mg/dL) while 24 patients (29.6%) had normal serum total bilirubin levels (≤1.2 mg/dL).

Conclusion
Serum total bilirubin level appears to be a promising new laboratory marker for diagnosing acute appendicitis and have a predictive potential for the diagnosis of complicated appendicitis Keywords: Acute Appendicitis; Hyperbilirubinemia; Serum Total Bilirubin

Introduction

Acute appendicitis (AA) is identified as an inflammation of the inner lining of the vermiform appendix that spreads to its other parts. Despite diagnostic and therapeutic advancement in medicine, appendicitis remains a clinical emergency and is considered one of the more common causes of acute abdominal pain [2].

Appendicitis is one of the more common surgical emergencies, and it is one of the most frequent causes of abdominal pain. In Asian and African countries, the incidence of acute appendicitis is probably lower (5- 6.5% of populations) because of the dietary habits of the inhabitants of these geographic areas. The incidence of appendicitis is lower in cultures with a higher intake of dietary fiber. Dietary fiber is thought to decrease the viscosity of feces, decrease bowel transit time, and discourage the formation of fecaliths, which predispose individuals to obstructions of the appendiceal lumen [3].

For a long time, the preoperative diagnosis of acute appendicitis (AA) is largely relied on the clinical assessment, previous experience, total white blood cell (WBC) counts, neutrophils percentage or a combination of several examinations. These traditional methods are quite non-specific. Recently ultrasonography and computed tomography (CT) were applied in the diagnosis of AA. However, ultrasonography still controversial if these imaging aided applications have actually resulted in significantly reduced cases of negative appendectomy and perforated appendicitis [4].

Hyperbilirubinemia is accumulation of bilirubin above physiological level in blood. In acute appendicitis occurs through bacterial invasion in appendix leads to transmigration of bacteria and release of TNF-alpha, IL6 and cytokines. These reach the liver through the superior mesenteric vein and may produce inflammation or dysfunction of the liver either directly or indirectly by altering hepatic blood flow with rising of total serum bilirubin.(1)

Materials and Methods

This is a prospective cohort study; Ninety four (94) of adult patients have right iliac fossa pain attending to the Emergency Department (ED) at Suez Canal university Hospital from the 15th of May 2015 to the 14th of May 2016.

Inclusion Criteria
All adult patients with acute right iliac fossa pain associated with one or more of the following: Tenderness, Rebound tenderness, Migratory pain, Anorexia, Nausea and vomiting, Fever, Elevated leukocyte count

Exclusion Criteria
Patients have one or more of the following criteria will be excluded from the study: Patients with any history of hepatic disorder and/ or abnormal liver function tests (LFTs), Patient with any hemolytic disorders, Patient with obstructive jaundice, Patient below age of 18 years, Pregnancy.

Methodology
All adult patients who will attend to Emergency Department in Suez Canal University Hospital complaining of right iliac fossa pain and have the following presentations in history, examination and investigations

History
Typically, the Patient Describes
Peri-umbilical colicky pain, which increases during the first 24 hours, then becoming constant and sharp, and migrates to the right iliac fossa, Loss of appetite is often a predominant feature, Constipation and nausea are often present.

Profuse vomiting may indicate development of generalized peritonitis after perforation but is rarely a major feature in uncomplicated appendicitis.

Examination
Vital Signs
Fever up to 38c, tachycardia
Abdominal examination: Localized tenderness and muscular rigidity to the right iliac fossa, Rebound tenderness is present but should not be elicited to avoid distressing the patient, with coughing the pain will often be localized to the right iliac fossa, The site of maximal tenderness is over McBurney's point, Percussion tenderness, guarding, and rebound tenderness are the most reliable clinical findings indicating a diagnosis of acute appendicitis, Further examination techniques that may aid in the diagnosis of appendicitis are Rovsig's sign (palpation of the left iliac fossa causes pain in the right iliac fossa), psoas stretch sign, and the obturator sign.

Investigations

Laboratory
Complete Blood Count (CBC) for WBCs count and Neutrophils Left Shift, C - reactive protein (CRP), Serum bilirubin will be added

Radiological
Abdomen X-ray, Pelvi-abdominal sonography
Histopathology
Histopathological examination of removed appendix The Patients those will fulfill criteria of Alvarado score for appendicitis which consist of: migration of pain to the right lower quadrant (1), anorexia (1), nausea and vomiting (1), right lower quadrant tenderness (2), fever (1), rebound tenderness (1), leukocytosis (2), neutrophils left shift (1) with total score more than 7 of 10 will undergo appendectomy then the removed appendix will be examined by pathologist to detect its pathological type and confirming pre-operative diagnosis and its relation to pre-operative bilirubin level.

Other patients have scored less than [7] and have elevated serum bilirubin will follow up for two days in ED of Suez Canal University Hospital for clinical or laboratory changes that suggest acute appendicitis and then undergo appendicectomy or pain relieved and discharged.

Procedure

Ethical clearance for the study was issued by Suez Canal University. Based on the selection criteria patients admitted with clinical diagnosis of acute appendicitis under the Department of Surgery. Eligible patients were briefed about the nature of the study and a written informed consent was obtained from the consented patients. Thorough history was taken and clinical examination was done for all patients and findings were recorded on predesigned and pretested proforma.

The following tests were carried out on admission: Routine blood investigations (Complete blood count, platelet count, reticulocyte count), Serum Bilirubin (Total and Direct bilirubin), Liver Function Tests (LFTs) which include; SGPT (Alanine transaminase), SGOT (Aspartate transaminase), Serum Bilirubin Total 0.6 - 1.2 mg/dL The results were grouped as 'Normal' or 'Raised' (hyperbilirubinemia) as per the above reference values.

Statistical Analysis
Data were tabulated, coded then analyzed using the computer program SPSS (Statistical package for social science) version 17.0 to obtain

Results

In our study population of ninety-four patients included and found that thirty-six male patient (38%) and fifty-eight female patient (62%). the mean age (27.6) years, and according to postoperative histopathological reports eighty-one patients (86.2%) had an inflamed appendix and thirteen patient (13.8%) had normal appendix and thirty-six patients (38.3%) had simple inflamed appendix (which are catarrhal or acute on top of chronic appendicitis), thirty-eight patients (40.5%) had acute suppurative appendicitis and seven patients (7.4%) had gangrenous appendicitis and thirteen patients (13.8%) had normal appendix. We found that Mean of serum total bilirubin 1.34 mg/dl with standard deviation 0.37 mg/dl. Serum total bilirubin distributed as following thirtyfour patients (36.2%) had total bilirubin less than 1.2 mg/dl and 60 patients (63.8%) had total bilirubin more than 1.2 mg/dl. the mean total bilirubin in simple inflamed 1.14 mg/dl, in acute suppurative 1.53 mg/dl and in gangrenous appendicitis 2.1 mg/dl (P<0.001), and total leukocyte count (TLC) was found elevated in 40 patients (42.6%) of the total ninety-four patients. Only thirty-three patients (40.7%) of eighty-one patients diagnosed post operatively with acute appendicitis had elevated TLC and seven patients had elevated TLC with a normal appendix. The mean of TLC count in all patients was 11498.77/mm3 ± 2920.38/mm3, with sensitivity 53.8% and specificity 59.2%, and found that CRP was positive in seventy-two patients 76.5% and negative in twenty-eight patients 23.5% with sensitivity 77% and specificity 23%

Finally Sensitivity, Specificity, Positive predictive value, Negative predictive value and accuracy were calculated from Statistical Analysis. Sensitivity and Specificity of bilirubin in predicting acute simple appendicitis, acute suppurative appendicitis and gangrenous appendicitis diagnosis were as follows: sensitivity 72.8%, specificity 92.3%, PPV 98.3%, NPV 35.3%, accuracy75.5%.

Patients enrolled for the study, 58 patients (62%) were females and 36 patients (38%) were males.

The overall mean age of all 94 patients was 27.69 ± 8.43 years (range from 19.26– 36.12 years). The average age in males and females was 29.44 ± 9.84 years and 26.6 ± 7.3 years respectively.

Post-operative histopathological examination of removed appendix in 94 patients revealed that Normal appendix in13 patients (13.8%), simple inflamed 36 (38.3%), acute suppurative 38 (40.5%), gangrenous 7 (7.4%)

Mean serum total bilirubin in normal appendix was 0.95md/dl, simple inflamed 1.14 mg/dl, acute suppurative 1.53 mg/dl and in gangrenous appendicitis 2.1 mg/dl.

Among 36 patients whom have serum total bilirubin <1.2 mg/dl found 12 patients have normal appendix, 22 have simple inflamed, 2 patients have acute suppurative appendicitis and no patient have gangrenous appendicitis, while among 58 patients have serum total bilirubin > 1.2 mg/dl found one patient have normal appendix, 14 patients have simple inflamed, 36 acute suppurative appendicitis and 7 patients have gangrenous appendicitis.

Among patients have TLC less than 11000 found 6 patients have normal appendix and 48 have acute appendicitis, while in patients have TLC more than 11000 found 7 patients have normal appendix and 33 patients have acute appendicitis

When Cutoff value 1.15 mg/dl found that sensitivity 61%, Specificity 76.9 %, PPV 88%, NPV 41.67%, Accuracy 65.3%, while cutoff value 1.35 mg/dl found that sensitivity 89.5%, Specificity 83.3%, PPV 85%, NPV 88.2%, Accuracy 88.2%, while cutoff value 1.85 mg/dl found that sensitivity 85.7%, Specificity 89.5 %, PPV 60%, NPV 97.14%, Accuracy 88.89%.

Discussion

The study was taken up with this thought that is it possible to add serum total bilirubin as a new laboratory marker to aid in the diagnosis of acute appendicitis, decrease removal of a normal appendix and preventing impeding complications of acute appendicitis.

The study population of ninety-four patients included and found that thirty-six male patient (38%) and fifty-eight female patients (62%). The mean age (27.6) years; While in Emmanuel et al in his study including 472 patients, 254 patients (53.8%) were male and (46.2%) female and the mean age was (27) years [7]. While in Eren et al study group of 162 patients consisted of 97 (60%) men and 65 (40%) women with a median age of 36 years [8]. So our

study differed from other study as female more than males due to female have other causes of right iliac pain and female in Egypt less educated than others and this the reason that removal of a normal appendix more in female patients in our study.

According to post-operative histopathological reports of the study; eighty-one patients (86.2%) had an inflamed appendix and thirteen patients (13.8%) had a normal appendix. While Emmanuel et al in his study regarding histopathological reports 386 patients (82%) had an inflamed appendix and 86 patients (18%) had a normal appendix [7].. In Eren et al study Histopathological examinations revealed an inflamed appendix in 141 (87%) patients and twentyone patients (13%) had a normal appendix [8]. So removal of a normal appendix still has a significant incidence in our study and other studies.

While Eren et al in his study Histopathological examinations revealed normal appendix in twenty-one (13%) patients, noncomplicated acute appendicitis in one-hundred (62%), and appendiceal gangrene/perforation forty-one (25%) patients [8]. Estrada et al in his study 116 patients (68%) had evidence of acute suppurative appendicitis and forty-one patients (24%) had gangrenous/perforated appendicitis on final histopathologic analysis and thirteen patients (8%) had a normal appendix [9]. So in our study the majority of removed appendix were acute suppurative which like Estrada et al study, but in our study percent of gangrenous appendicitis less than other studies as incidence of gangrenous appendicitis is more in males and in our study females was more than males.

Surgical procedures were conducted in 98.2% of cases. Definitive diagnosis by histopathology was confirmed in 77 cases (71.3%). The overall negative appendectomy rate was 31 cases (28.7%) (Mainly females). Sensitivity and specificity of the Alvarado scoring system were considered to be 93.5% and 80.6% respectively. Positive and negative predictive values were 92.3% and 83.3%, respectively, and accuracy was 89.8% [10]. Memon et al found that its role in females was not satisfactory and needs to be supplemented by other means which like our study.

The study showed that the mean of serum total bilirubin 1.34 mg/dl with standard deviation 0.37 mg/dl. Serum total bilirubin distributed as following thirty-four patients (36.2%) had total bilirubin less than 1.2 mg/dl and 60 patients (63.8%) had total bilirubin more than 1.2 mg/dl. The mean total bilirubin in simple inflamed 1.14 mg/dl, in acute suppurative 1.53 mg/dl and in gangrenous appendicitis 2.1 mg/dl (P<0.001). In Chaudhary et al in his study including 50 patients, serum total bilirubin was raised in thirty-eight (76%) patients whereas twelve (24%) cases had normal serum total bilirubin level. Serum total bilirubin was more elevated in gangrenous and perforated appendix than those in acute appendicitis (P<0.001). The mean of serum total bilirubin in acute appendicitis cases without perforation or gangrene was 1.52 mg/dl and the mean of serum total bilirubin in cases with perforated or gangrenous appendix was 3.62 mg/dl for gangrenous/ perforated appendicitis [11]. Eren et al study found that Total and direct bilirubin levels were also significantly elevated in patients with acute and gangrenous/perforated appendicitis (p < 0.01).

Depending on multivariate analysis, elevated total bilirubin levels were associated with five times, and elevated direct bilirubin levels were associated with 36 times greater risk for appendiceal gangrene/perforation [8]. Emmanuel et al study The mean bilirubin levels were higher for patients with simple acute appendicitis compared to those with a non-inflamed appendix and significantly more patients in this group had hyperbilirubinaemia on admission (30% vs 12%, p<0.001). The odds of a patient with hyperbilirubinaemia having simple acute appendicitis were greater than three times higher than those without hyperbilirubinaemia. The specificity of hyperbilirubinaemia for simple acute appendicitis was 88% and its positive predictive value was 91%. Patients with a perforated or gangrenous appendix had higher mean bilirubin levels than those with simple acute appendicitis (2.3mg/dl vs. 1.8mg/dl, p=0.01). Significantly more patients with a perforated or gangrenous appendix had hyperbilirubinaemia than those with simple acute appendicitis (60% vs. 30%, p<0.001). The specificity of hyperbilirubinaemia for a perforated or gangrenous appendix was 70% [7]. So all studies found that elevated total serum bilirubin have moral significance in diagnosis of acute appendicitis.

In our study, the total leukocyte count (TLC) was found elevated in 40 patients (42.6%) of the total ninety-four patients. Only thirty-three patients (40.7%) of eighty-one patients diagnosed post operatively with acute appendicitis had elevated TLC and seven patients had elevated TLC with a normal appendix. The mean of TLC count in all patients was 11498.77/mm3 ± 2920.38/mm3, with sensitivity 53.8% and specificity 59.2%. While in Emmanuel et al study found that TLC sensitivity when differentiating between simple inflamed appendix and non-inflamed appendix is 82% and specificity 60% and when differentiating between simple inflamed appendix and gangrenous appendix found TLC sensitivity 93% and specificity 19% [7]. In our study, TLC specificity was as other study while sensitivity in our study was low than other study due to cutoff point of our study was 11000/mm3 while Emmanuel et al study was 10400/mm3.

In this study we found that CRP was positive in seventy-two patients 76.5% and negative in twenty-eight patients 23.5% with sensitivity 77% and specificity 23% while in Jangjoo et al study102 cases undergo appendicectomy with CRP positive (≥ 14 mg/l) and found that 83 patients (81/4%) had acute appendicitis and 19 (18/6%) had normal appendices by post-operative histopathological reports. CRP test shows 59% sensitivity and 68% specificity [12]. So both studies show that the measurement of CRP levels is not an ideal diagnostic tool for ruling out or determination of acute appendicitis.

In our study, the Sensitivity, Specificity, Positive predictive value, Negative predictive value and accuracy were calculated from Statistical Analysis. Sensitivity and Specificity of bilirubin in predicting acute simple appendicitis, acute suppurative appendicitis and gangrenous appendicitis diagnosis were as follows: sensitivity 72.8%, specificity 92.3%, PPV 98.3%, NPV 35.3%, accuracy75.5%. While in Emmanuel et al study when differentiating between simple inflamed appendix and non-inflamed appendix found that hyperbilirubinemia had sensitivity 30%, specificity 88%, PPV 91%, and NPV 24%, and when differentiating between simple inflamed appendix and gangrenous appendix found that hyperbilirubinemia had sensitivity 60%, specificity 70%, PPV 21% and NPV 92% [7].

We see that patients with acute suppurative appendicitis and gangrenous appendicitis had significantly elevated serum total bilirubin as compared to that of simple appendicitis. So, patients with features suggestive of appendicitis with elevated serum total bilirubin are more susceptible of having acute suppurative appendicitis and gangrenous appendicitis than those with normal or slightly elevated total serum bilirubin.

Conclusion

Serum total bilirubin level appears to be a promising new laboratory marker for diagnosing acute appendicitis and have a predictive potential for the diagnosis of complicated appendicitis

  1. Juric I, Primorac D, Zagar Z, Biocic M. Pavic H (2001) frequency of portal and systemic bacteraemia in acute appendicitis. Pediatric international journal 43(2): 152-156.
  2. Fitz R (1886) Perforating inflammation of the vermiform appendix with special reference to early diagnosis and treatment. American Journal of Medicine and Science 92: 321-346.
  3. Güller U, Rosella L, McCall J, Brügger LE, Candinas D (2011) Negative appendicectomy and perforation rates in patients undergoing laparoscopic surgery for suspected appendicitis. British Journal of Surgery 98: 589-595.
  4. Humes DJ, Simpson J (2006) Acute appendicitis. BMJ 333(7567): 530- 534.
  5. Dawson B (2004) Basic and clinical biostatistics. 4th ed. USA Mc- Graw-Hill 435- 436.
  6. Khan S (2009) The diagnostic value of hyperbilirubinemia and total leukocytic count in evaluation of acute appendicitis. Journal of Clinical and Diagnostic Research 1(3): 1647-1652.
  7. Emmanuel A, Murchan P, Wilson I, Balfe P (2011) The value of hyperbilirubinemia in the diagnosis of acute appendicitis. Ann R Coll Surg Engl 93: 213-217.
  8. Eren T, Tombalak E, Ozemir A, Leblebici M (2015) Hyperbilirubinemia as a predictive factor in acute appendicitis. European Journal of Trauma and Emergency Surgery 42(246): 1-6.
  9. Estrada J, Petrosyan M, Krumenacker J, Huang S (2007) Hyperbilirubinemia in Appendicitis: A New Predicator of Perforation. Journal of Gastrointestinal Surgery 11(6): 714-715.
  10. Memon ZA, Irfan S, Fatima K, Iqbal M, Sami W (2013) Acute appendicitis: diagnostic accuracy of Alvarado scoring system. Asian J Surg 36 (4): 144-149.
  11. Chaudhary P, Kumar A, Saxena N, Biswal C (2013) Hyperbilirubinemia as a predictor of gangrenous/perforated appendicitis: a prospective study. Ann Gastroenterol 26 (4): 1-7.
  12. Jangjoo A, Varasteh A, Bahar M, Meibodi N (2011) Is C-reactive protein helpful for early diagnosis of acute appendicitis?. Acta. Chir. Belg 111(4): 219-222.