POSSUM A Good Indicator of Morbidity and Mortality in Calcular Disease of Biliary Tract

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1 Original Article JK-PRACTITIONER POSSUM A Good Indicator of Morbidity and Mortality in Calcular Disease of Biliary Tract Nazir A. Wani, MS. FICS; FRCS, Fazlul Q. Parray, MS., Gazalla Safdar, MS. ABSTRACT A Prospective study on 500 patients, admitted for calcular disease of biliary tract, was undertaken at Sher-i-Kashmir Institute of Medical Sciences, Soura Jammu & Kashmir India for assessing the validity of POSSUM SCORING SYSTEM along-with many other pre-operative and operative risk factors. All patients were diagnosed cases of benign biliary calcular disease. The patients were subjected to appropriately indicated surgical procedures, observed and followed up post operatively and co-related with 0 days morbidity and mortality rates. Post-operative morbidity was 4% and mortality was less than 1% Local wound infection, postoperative pyrexia and local pain were the commonest complications observed. POSSUM SCORING SYSTEM was found to have a good predictive value in predicting the postoperative morbidity and mortality with sensitivity of 60% and specificity of 99% with positive predictive value of 100%. JK-Practitioner005;1(1):6-10 Authors affiliations : Prof. Nazir A. Wani Fazlul Q. Parray Gazalla Safdar Deptt. of Surgery Sher-i-Kashmir Institute of Medical Sciences Soura, Srinagar Kashmir (India) Accepted for publication August 004 Correspondence to: Dr. Fazlul Qadir Parray 44-Rawal Pora, Govt. Housing Colony Sanat-Nagar, Srinagar , J&K (INDIA) Tele No : , fazlparray@rediffmail.com INTRODUCTION Conventional Cholecystectomy still continues to be the cornmonest modality of treatment for benign 1 biliary tract disease. Recenly a number of minimally invasive surgical and non-surgical alternatives have been introduced, still an appreciable number of patients have to bear the brunt of post-operative morbidity and mortality. Detailed pre-operative evaluation, safe anesthesia, improved surgical techniques and an intensive post-operative monitoring have all contributed for decreasing the morbidity and mortality associated with these procedures. However despite advances in the supportive care, a spectrum of various risk factors may increase the morbidity and mortality following surgery on the biliary tract. A number of studies have been conducted to identify various clinical, biochemical and operative parameters responsible for increasing the morbidity and mortality in postoperative patients of benign biliary calcular disease. Hence, many scoring systems were devised to predict the risk of mortality with varying degrees of accuracy, ignoring morbidity -6 universally. The ideal scoring system for surgical audit purpose should assess mortality and morbidity and should allow audit retrieval of the surgical Key Words: Biliary, Possum, Morbidity, Mortality success. It should be quick and easy to use and should be applicable to all general surgical procedures in both the emergency and elective setting. It should be of use in all types of hospitals and should provide educational information. Finally it should be possible to integrate the scoring system into pre-existing audit programmes with minimum of disruption. Copland, Jones and Walters devised a dual scoring system POSSUM (Physiological and Operative Severity Score for the enumeration of Mortality and morbidity). This is a 1-tactor, four grade physiological score. While this pre-operative physiological score yields a statistically predictive risk of morbidity and mortality for the patients overall, with inter-group differences depending on the nature of surgical procedure. Logistic regression analysis of all data enabled a six factor, surgical operative score to be evolved which compensated for the type of surgical procedure. MATERIAL AND METHODS: This prospective study was conducted in the department of General Surgery at Sher-i-Kashmir Institute of Medical Sciences, Soura India on 500 patients of diagnosed calcular disease of biliary tract over a period of 18 months (August 199 to January 1994). 6

2 Table -1 Complications (n=1) S. No. Post-operative Complications No. of cases 1. Wound infection 18. Pyrexia of unknown origin 1. Chest Infection Septicemia 0 5. Bile leak 0 6. Wound disruption 0 7. Retention of Urine Urinary tract infection Thrombophlebitis Incisional Hernia Cardiac arrhythmias Anastamotic leak and Intra- 01 abdominal collection Upper GI Bleed Hemobilia DIC 01 Each patients full record relevant history, examination, investigations, operative procedures and post-operative complication were maintained and analyzed. The types of surgeries performed were categorized into three groups : TYPE-I: TYPE.II: Cholecystectomy/ Cholecystostomy only. Cholecystectomy with CBD exploration with T tube drainage, TYPE-III: Cholecystectomy with papillotomy/ sphincteropeasty/choledochoduodenostomy or choledocho -jujenostomy. All the operations performed were open procedures and no laparoscopic operation is included. Complications were assessed by clinical observations, relevant bacteriological and radiological tests; carried out only when indicated. THE STATISTICAL ANALYSES USED WERE: 1. Multiple logistic regressions to test the relationship of pre-operative factors with post-operative morbidity and mortality.. Chi-square tests to analyze the relationship of postoperative mortality, complications and the relationship of preoperative factors and the postoperative complications.. Fisher s exact test where numbers were small. All the patients of study group were scored according to POSSUM SCORING SYSTEM preoperatively with physiological parameters at discharge using the operative severity score. Using the outcome as a dichotomous dependent variable, we derived multiple logistic regression equations for both morbidity and mortality. Significance was assessed using model x. Differences between observed and assessed outcomes were assessed using chi-square tests. Overall we studied the effect of 5 potential risk factors in our study group of 500 patients to know about the predictive value of POSSUM SCORING SYSTEM in predicting the post-operative morbidity and mortality in benign biliary tract disease. RESULTS Out of 500 patients of our study group, 108 were maees and 9 females male to female ratio 1:4. Benign biliary tract disease comprised 0% of the total General Surgical Admission. Post operative morbidity was 4% while the post operative mortality was 1%. Local wound infection and post operative pyrexia were the commonest complications observed. (See Table 1) Out of 5 patients risk factors considered in our study we found 16 factors showed significant association with morbidity. These factors were: _ 1. Age >50yrs.. Pulse rate >100 (H/o fever, chills and cholangitis). WBC count >11000/cumm 4. Blood urea >4mg. % 5. Na <10 mg/dl 6. Potassium <mg /dl 7. Operations of major severity Type iii > Type II > Type II I Multiple procedures or H/O previous surgery on biliary tract. 9. Positive h/o Jaundice. 10. H/O associated medical illness especially diabetes. 11. Prothrombin Index < 80% 1. Sr. Creatinine >1.mg % 1. Sr. Alkaline phosphatase >100 iu/l 14. Sr. bilirubin >mg%. 15. Positive blood culture. l6. Operating time > 1 and half-hour. There were 5 deaths; four were due to a cause directly related to the disease or complications which included D.I.C in one patient, and septicemia in three patients while one death was related to myocardial infarction. (Also see table II & II) We also found that the number of risk factors present in the preoperative period have a direct bearing on operative morbidity and mortality (table IV). Our study based on 50%- predicted risk revealed that the indicator fielded a sensitivity of 6% and a specificity of 94% fir the prediction of morbidity in the postoperative period. While evaluating the patient preoperatively, presence of risk factors 1-5 or more in that order multiplies the risk involved with the surgical outcome. Patient with five or more than 5 risk factors being at highest risk of getting postoperative complications. Scoring system was also in a position to predicted the possibility of complication to the tone of 6% and on the contrary, it was helpful in predicting 94% cases with no complication. Hence, we found the system favourable to a noticeable extent in predicating morbidity and mortality. DISCUSSION Now-a-days, the management modalities of most of the diseases are changing for better all over the world. The slogan of quality care and cure is seeing its dawn because of better understanding of disease pathogenesis, better investigative support, better spectrum of drugs, better diagnostic and technical equipments and above all, selfcritical appraisal or audit by using various scoring systems In surgery the audit has increased in importance over the past few years, both as an educational process and as a means of assessing the quality of surgical care. Scoring would seem to be the best method available for assessing the risk of mortality and morbidity, but most of the scoring systems could not match our expectations as being readily applicable to the audit. In order to minimize the risk 7

3 TABLE-II (PHYSIOLOGICAL SCORE) MORBIDITY No Clinical Parameters Total Cases with X P Remarks No. of Post-operative Cases Complications 1. Age in years < <.001 H.S > Cardiac Signs or Chest Radiograph Yes >.50 N.S. No Respiratory Disease Yes >.50 N.S. No Systolic B.P >.50 N.S <171 Nill 5. Pulse-rate N.S. <100/mt <.001 H.S. >100/mt Glasgow coma Scale >.05 N.S. 7. Hemoglobin values >10g% >.05 N.S. <10g% WBC Count < <0.001 H.S = > Urea >40mg% <.001 H.S <40mg% Sodium >140mg% <.001 H.S <10mg% Potassium <mg <.001 H.S >mg ECG Normal >0.50 N.S Atrial fibrillation (rate60-90) 1 >5 ectopics/min 1 Table : Showing statistical co-relation of various operative parameters with mobidity. Note: N.S: Not Significant, H.S: Highly Significant,<:Less than, >:More than of inappropriate score usage, we utilized the Scoring System devised by copelend, Jones and Walters i.e., POSSUM SCORRING. Our prospective study showed female preponderance of 4-7 4:1as observed by others. Also, the morbidity and mortality was quite low and favourably comparable with 6,8,9 national and international figures. All the sixteen identified potential risk factors were found to have an independent significance in predicting morbidity, which is in 5,6,10-1 accordance with international literature The process of POSSUM Scoring when applied during the present study JK-PRACTITIONER based on 50% predicted risk revealed that the indicator yielded a sensitivity of 6% and a specificity of 94% for the prediction of morbidity in the post-operative period. Also it was quite evident that scoring system has been in a position to predict the possibility of complication to the tune of 6% and on the contrary, it was helpful in predicting 94% cases with no complication. Moreover, based on 50% predicted risk of death and the final outcome, the sensitivity was 60% and specificity being 99% Hence, we found the system favourable to a noticeable extent like other studies in predicting,1 morbidity and mortality. Also the corelation between the predicted and observed rates for morbidity and mortality was statistically significant (P<0.050) as observed by coplend and 1,14,15 others. (Table V) In recent surgical review article on the subject of risk scoring in surgical patients, it was concluded that the POSSUM SCORE is the most appropriate of the currently available score of general surgical practice in the 16 estimation of risk of dying. When used for complex surgeries like liver transplantation, it could predict in part the adverse outcome of surgery by several pre-operative and intra operative factors.17 POSSUM has also been evaluated extensively in both general and specialist surgery while there are problems with both data collection and analysis, but when used correctly POSSUM can usefully compare outcome between surgeons and hospitals. In specialist surgery, however, individual regression equations may be needed for 18 each index procedure The study used to assess the predictive value of the said scoring system for morbidity and mortality in laparoscopic chotecystectomy in patients above 80 years was found to be small single centered retroscopective study along with 19 lack of clibration in the said surgery. Although POSSUM may not be able to replace highly specific scoring systems for individual disease states or the intensive care patient, it does appear to provide an efficient indicator of the risk of morbidity and mortality in the patients of benign billiary tract disease. Thus, we conclude that POSSUM Scoring System is accurate and useful for surgical audit in-patients of benign biliary tract disease, however, we reaffirm that it should be used as an adjunct to surgical audit. We also recommend that the value of POSSUM Scoring in identifying high risk patients undergoing surgery for 8

4 TABLE-III (PHYSIOLOGICAL SCORE) MORBIDITY S.No Clinical Parameters Total Cases with X P Remarks No. of Cases Post-operative 500 Complications 1. Operative sverity Type I <.001 H.S Type II 78 1 Type III Blod loss <100ml >.50 N.S >100ml Peritoneal soiling None 479 Minore >.50 N.S Local pus 1 6 Free bowel contents 4. Malignancy None >.50 N.S 5. Multiple procedures <.001 N.S 06 > 6. Mode of Surgery Elective <.001 H.S Emergency Note:. N.S: Not Significant, H.S: Highly Significant, <:Less than,>:more than Table:. Showing statistical co-relation of various operative parameters with morbility. TABLE-IV Relationship of risk factors with morbidity in benign biliary tract surgery No. of Risk Total Cases No. Cases with Complication Odds Ratio Factors (%) No. (%) Nil 110 (.00) 01 (.91) (4) 0 () (0) 0 () (14) 0 (4) (1) 05 (8) or more 4 (9) 08 (19) 4.91 While evaluating the patient preoperatively, presence of risk factors 1-5 or more in that order multiplies the risk involved with the surgical outcome. Patient with five or more than 5 risk factors being at highest risk of getting postoperative complications. TABLE-V Preedicated rate Vs. observed rates for morbidity and mortality Predicated rate Observed rate (%) Mortality Morbidity Remarks: Correlation between predicted and observed rates is significant)p<.05) 9

5 benign biliary tract disease needs to be evaluated and compared in further studies. References 1. Colcock BP, Mc Manus JE : Experience with 156 cases of cholecystites and cholelithiasis. Surgical Gynaecology and Obstectrics 1955; 101: Glenn, F : Cholecystectomy in high risk patients with biliary tract disease. Ann Surg; 1977, Copeland GP, Jones D, Waters M: POSSUM, a scoring system for surgical audit. Br. J. Surg; March 1991; 78 : Dowdy GE and Waldron GW : Importance of co-existant factors in biliary tract surgery. Archives of Surgery 1964; 88:14-5. MC Sherry CK, Glen F :The incidence and cause of death following surgery for nonmalignant biliary tract disease. Ann Surg 1980; 191: Chrungoo RK, Choudry NH, Kariholu PL, Pathak BSN, Kapoor KL: Factors effecting morbidity in biliary tract surgery. Ind J Surgery 1990; 5: Landeu ofer, Kott itamac, Deutsch MB, Rafel Reiss :Multifactional analysis of septic bile and septic complications in biliary surgery. Would J Surg 199; 16 : Al-Awami SM, Al Breiri H, Abdul Khader AS: Wound infection following biliary surgery-a prospective study. Int Surg 1991; 76: Rajan Saxena, Pradeep Kumar, SP Kaushik; Spectrum of bening biliary tract disease as seen at Chandigarh. Ind Journal of Surgery 1991; 5 (8-9) : Blamey NL, Fearon Ch, Gilmour DH : Prediction of risk in biliary Surgery; Br. J-Surgery 198; 70: Cheng Hisu, Fang Ku Pheng, Wing-yiu liu: Factors affecting morbidity and mortality in biliary tract surgery World J Surgery 199; 16: Copeland GP. Jones DR,. Cossart, L de, Comparison of POSSUM with Apache-ll for prediction of outcome from a surgical high dependency unit. Br. J Surgery Dec. 199: 79: Scriven MW, Burgees E, Edwards A, Morgan AR: Cholecystectmy : a study of patient satisfaction. JR Coll Surg Edinb, April 199; 8: l4. Copeland GP, Sagar P, Brennan J, Roberts G, ward J, cornford P. Risk adjusted analysis of surgeon performance, 1 year study. Br. J Surg 1995; 8: L5. Wijesinghe LD, Mahmood T, SCOTT DJA, Berridge DC, Kent PJ and Kester RC: Comparison of POSSUM and the Portsmouth predictor equation for predicting death following vascular surgery. Br. J. surgery1998, 85, Jones HJ, Coggins R, Lafuente J, Cossart L de; Value of a surgical high dependency unit. Br. J. Surg 1999 Dec; 86(1) : Guerrero EB, Feierman DE, Barclay GR, Parides MK, Sheiner PA, Mythen MG, Levine DM, Parker TS, Carroll SF, White MK, Winfree WJ: Preoperative and intraoperative predictors of post-operative morbidity, poor graft function, and early rejection in 190 patients undergoing liver transplantation. Arch Surg. 001; 16: l Neary WD, Healther BP, Earnshaw JJ. The physiological and operative Severity Score for the enumeration of Mortality and morbidity (POSSUM). BJS Jan 00; 90() : Tambyrala AL, Kumar s, Nixon SJ: POSSUM Scoring for predicting morbidity and mortality after laparoscopic Cholecystectomy in patients over 80 years old. edu.rcsed.ac.uk/auditsymposium00.html 10