Original article: Incidence of renal failure in postoperative period of cardiovascular surgeries in India 1Dr.Abhijeet Nikam*, 2 Dr. Abhay Sadre 1Department of Medicine, P.Dr. D.Y.Patil Medical College and Hospital, Pimpri, Pune, Maharashtra, India. 2 Department of Medicine, B.J.Medical College, Pune, Maharashtra, India. *Corresponding author: abhijeetnikam1@rediffmail.com Abstract: Introduction: In present day, cardiac surgery is being performed on much large scale than in past. However renal dysfunction persists as a major postoperative complication following cardiac surgery and carries grave prognosis. With this background in mind present work was planned to study incidence of real failure in cardiovascular surgery patients. Material & methods : The work was carried out of at a General Hospital over a period of 12 months.a total of 110 patients underwent cardiovascular surgery over a period of 12 months of these 40 patients with renal failure were studied in details. Observations & Results: As age increases incidence of renal failure goes on increasing. Incidence of renal failure in present study was 36.36%. Incidence of Renal failure was more in CABG group as compared to valve/repair/replacement or surgery for congenital heart disease. Conclusion: Older age, hypertensio, diabetes mellitus, chronic heart failure and previous renal insufficiency were significant predisposing risk factors for development of postoperative renal failure after cardiovascular surgeries. INTRODUCTION : In present day, cardiac surgery is being performed on much large scale than in past. Cardiac surgery has also become more safe as compared to last decade. However renal dysfunction persists as a major postoperative complication following cardiac surgery and carries grave prognosis.the overall reported incidence of renal dysfunction following cardiac surgical operations various from 0.1% for operations performed under hyperthermia alone to as high as 30.3% in patients who underwent open procedures but in whom the diagnosis of renal failure was made only from a retrospective analysis of renal function studies.(1) With this background in mind present work was planned to study incidence of real failure in cardiovascular surgery patients. MATERIALS AND METHODS : The work was carried out of at a General Hospital over a period of 12 months.a total of 110 patients underwent cardiovascular surgery over a period of 12 months of these 40 patients with renal failure were studied in details. All patients undergoing cardiovascular surgeries were included in the study. Prospective 110 patients who undergo cardiovascular surgeries in the period of 12 months were studied. Details of history of hypertension, diabetes mellitus, previous renal insufficiency, ischemic heart disease, congestive cardiac failure and other co morbid illnesses were recorded.previous renal insufficiency is defined as serum cretinine value >1.5mg in the preoperative period.patient s diagnosis, nature of surgery performed and anesthetic agents used were 113
recorded.total duration of operation, duration of cardiopulmonary bypass, duration of aortic crossclamping and duration of preoperative hypotension were recorded. Serum creatinine values were recorded pre-operative, 24 hours, and 7 days of postoperative days. In patients with Renal failure in addition serum creatinine value were recorded alternate days till final outcome. Highest serum creatinine value in postoperative period was noted.we had chosen a serum cretinine value of greater than 50% over the baseline value after cardiovascular surgery as level for definition of renal failure in postoperative cardiovascular surgery.outcome of patients of forms of derangement of renal function or no derangement recorded. OBSERVATIONS & RESULT: Table 1) Incidence of renal failure in different age groups Age group ( Yr) No. of patients Renal failure Percentage (%) <20 30 07 23.33 21-39 47 14 29.78 40-59 27 13 48.14 >60 06 06 100 Total 110 40 36.36 X 2 =15.2, df =3, P>0.01 significant. As age increases incidence of renal failure goes on increasing. Incidence of renal failure in present study was 36.36%. Table 2) Incidence of Renal failure in different cardiac surgeries. Nature of cardio vascular surgery No. of patients Renal failure % CABG 23 17 73.91 Valve Repair/Replacement 53 13 24.52 Operation for congenital heard disease 32 08 25.00 Others 02 02 100 Total 110 40 36.36 X 2 =19.2, df =2, P>0.001 Highly significant. Incidence of Renal failure was more in CABG group as compared to valve/repair/replacement or surgery for congenital heart disease. 114
Table 3) Incidence of RF in relation to risk factors. Risk factor Total No. Renal failure % X 2 df=1 HTN 15 12 80.00 47.9 DM 11 09 81.81 43.9 CHF 19 13 68.42 41.2 Pre. RI 05 05 100 41.2 No risk factors 70 02 2.85 P<0.001 Highly significant.when compared no risk factor group with in all other groups with risk factor, renal failure incidence was found more. The differences were highly significant. Table 4) Severity of Renal failure as per maximum serum creatinine in postoperative period. Max. serum creatinine in postoperative period No. of patients % of Total 110 Mild (1.5-2.5 mg%) 29 26.36 Moderate (2.6-5.0mg%) 05 4.54 Severe (> 5.0 mg %) 06 5.45 6 out of 40 patients had severe renal failure after cardiovascular surgery. 29 out of 40 patients had mild renal failure. DISCUSSION Consecutive 110 patients undergoing cardiovascular surgery at general hospital were selected in present study in the period of 12 months. Analysis of the data of our study revealed that maximum umber of years age group underwent surgery for both valve replacement and CABG. Various studies have been undertaken in the past comparing the presence of significant risk factors to the incidence of postoperative renal failure.premorbid patients (i.e.47 out of 110) were in the age group of conditions like hypertension, diabetes 21-39 years. This was observed, as the natures of mellitus were associated with development of surgery were predominantly valve repair or postoperative renal failure. Diabetes mellitus was replacement (i.e. 53 out of 110).The 110 patients compromised of 51 males and 59 females. The malefemale ratio of our study was 0.86. only 6 patients associated with almost twofold-increased risk for development of renal failure.(2,3) Chronic heart failure considerably increases risk of were above age of 60 years and they underwent renal failure postoperatively. Previous renal CABG while 30 patients less than 20 years insufficiently or impaired renal function was underwent surgery for valve repair/replacement and associated with almost twofold increase in for congenital Heart disease 27 patients in 40-59 postoperative renal failure rate. 115
In the view of these findings, we indentified patients with risk factors; stratify the risk for developing postoperative renal failure. Our study included 19 patients with chronic heart failure. 15 patients with hypertension, 11 patients with diabetes mellitus and 5 patients with diabetes mellitus and 5 patients with previous renal insufficiency. Major risk factors in CABG surgery were hypertension and diabetes mellitus. While valve replacement/repair and surgery for congenital heart disease consist chronic heart failure as major risk factor. Incidence of renal failure in postoperative period of cardiovascular surgeries differs in reported series being influenced by the criteria used for its definition. Overall reported incidence various from 0.1% to as high as 30% who underwent open procedures. Yeboah et al (1972) reported incidence of mild and severe renal failure 26% and 4.7% respectively in the study of 428 open heart operations.(4) Natures of surgeries included in this study were valve replacement/repairs and surgery for congenital heart disease. Abel et al (1976) studied 500 patients of cardiovascular surgery. (5)Out of them 35 developed either moderate or severe renal failure (7%) and 102 developed mild renal failure (20%.). He included all types of cardiovascular surgeries performed like CABG. Valve replacement, surgery for congenital heart disease and miscellaneous operations. The overall incidence of renal failure in present study was 36.36% (40 out of 110 patients), out of which 26.36% developed mild renal failure, 4.54% moderate and 5.45% developed severe renal failure.(6,7) Incidence of renal failure goes on increasing as age increases. Our study showed that 13 out of 27 patients (48.14%) had renal failure in 40-59 years age group. 6 out of 6 patients (100%) had renal failure above the age of 60 years.christina et al (1998) showed that age was an important prognostic factor for the development of postoperative renal failure. Patients above 70 years of age had twofold increased risk and above 80 years had fourfold increased risk for development of renal failure,. Impaired renal autoregulation and preoperative hemodynamic instability are more in older patients and it increases risk of postoperative renal failure. Abel et al (1976) showed that older age (mean age >57.6 years) was associated with development of postoperative renal failure with high prevalence. Our study showed that 17 out of 23 patients (73.91%) developed renal failure after CABG surgery compared with valve replacement or operations for congenital heart disease. Abel et al showed that there was no significant difference in the over all incidence of renal failure regardless of type of operative procedure.(5) This high incidence of renal failure in CABG surgery found in our study was due to older age group subjected to surgery for ischemic heart diseases as compared to other surgeries; in addition CABG surgical patients had predominantly hypertension and diabetes mellitus as risk factors which by themselves are risk factors for the development of postoperative renal failure.in valve replacement surgery 4 out of 7 patients (57.14%) who undergo double replacement surgery had renal failure.yeboah et al (1972) showed that 28 out of 56 (50%) patients developed renal failure in multiple valve replacement surgery.(5) Our study, showed that there was definitely increased risk of renal failure with pre-operative risk factors like hypertension, diabetes mellitus, chronic 116
heart failure and previous renal insufficiently than with no risk factor. 9 out of 11 patients (81.81%) with diabetes mellitus, 12 out of 15 patients (80%) with hypertension, 13 out of 19 patients (68.42%) with chronic heart failure and 5 out of 5 patients (100%) with preoperative renal insufficiency developed renal failure postoperative as compared with 2 out of 70 patients (2.85%) who developed postoperative renal failure with no risk factor. Christina et al (1998) showed that diabetes mellitus was associated with almost twofold increase in postoperative renal failure rate.(8)the finding that elevated serum creatinine is significant risk factor for the developmene of subsequent renal failure was consistent with various studies by Abel et al (1976), Hilberman et al (1979).(4,9) Data mining techniques will be more helpful for accurate association confirmatory factors. (10) CONCLUSION: Older age, hypertension, diabetes mellitus, chronic heart failure and previous renal insufficiency were significant predisposing risk factors for development of postoperative renal failure after cardiovascular surgeries.cardiopulmonary bypass time more than 180 mins. REFERENCES: 1. Abel R.M., Buckley M.J., Austen W.G., Barnett G.O., Beck C.H. Jr, Fischer S.E. : Etiology, incidence and prognosis of renal failure following cardial operations. J. Thorac Cardiovasc. Surg 71:323-333, 1976. 2. Hou S.H., Bushinsky D.A., Wish J.B., Cohen J.H.: Hospital acquire renal insufficiency a prospective study. Am J Med. 74:243-8, 1983. 3. Montgo J.Z., Kalvnason G.M. and Guez L.B.: Renal failure and infection, medicine (Baltimore 47:1, 1968. 4. Abel R.M., Wick J.M., Beck C.H. Jr, Buckley M.J. and Austen W.G.: Renal dysfunction following open heart operations Arch Surg 108: 175, 1974. 5. Yeboah B.D., Aviva Petrie, J.L. Pead: Acute Renal failure and open Heart Surgery: British Medical Journal 1:415-448, 1988. 6. Chesney R.W., Kaplon B.S., Freedom R.M., Haller J.A., Drummond K.N. Acute renal failure: An important complication of cardiac surgery in intants. J. Pediatr 87:381-388, 1975. 7. Bhat J.G., Gluck M., Lowestein J., Baldwin D.S. L Renal failure after open heart surgery, An Intern Med 84:677-682, 1976. 8. Christina M.M., Laura S.D., James G.R., Anil Aggarwal: Renal dysfunction after myocardial Revascularization: Risk factors, Adverse outcomes and Hospital Resource Utilization, Ann of Internal Medicine. 128:194-203, 1998 9. Davis R.F., Lappas D.G., Kirklin J.K., Buckly M.S., Lowenstein E. Acute oliguria after cardiopulmonary bypass: renal functional improvement with low dose-dopamine infusion. Crit. Care Med. 10: 852; 1982. 10. Tayade MC, Karandikar PM, Role of Data Mining Techniques in Healthcare sector in India, Sch. J. App. Med. Sci., 2013; 1(3): June ; 158-160 Date of submission: 02 September 2013 Date of Provisional acceptance: 29 September 2013 Date of Final acceptance: 20 October 2013 Date of Publication: 04 December 2013 Source of support: Nil; Conflict www.ijbamr.com of Interest: Nil P ISSN: 2250-284X E ISSN :2250-2858 117