patients received brachial plexus block and group C (n=77), patients received local infiltration anesthesia. Chi-square test was used to compare between the ...
ARTERIOVENOUS FISTULA IN CHRONIC RENAL FAILURE PATIENTS: COMPARISON BETWEEN THREE DIFFERENT ANESTHETIC TECHNIQUES
Summany
The creation of arteriovenous fistula is an established form of therapy for patients with chronic renal failure. Anesthetic management in such patients is governed by the presence of risk factors such as hypertension, ischemic heart disease, diabetes, chronic pulmonary disease, anemia, coagulopathy, metabolic acidosis and/or hyperkalemia. In an attempt to improve the quality of anesthetic care and outcome we designed the present study to compare the different anesthetic thechniques which are used for creation of arteriovenous fistula. Retrospectively we reviewed 164
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* M.D. (Facharzt), Consultant Anesthetist, Department of Anaesthesia, King Khalid University Hospital. ** M.D. Asst. Professor & Consultant Anesthetist, King Saud Universiy, College of Medic~ne,King Khalid University Hospital, Department of Anesthesia. *** M.D. FRCS (Can), Assoc. Professor & Consultant, Division of Vascular Surgery, King Saud University. **** MB ChB, MSC, Senior registrar, Department of Anesthesia, King Khalid University Hospital. ***** MB ChB, MSC, Registrar, 644 Platts Lane, London, Ontario N6G, Canada. ****** MB ChB, JBA, Senior registrar, Department of Anesthesia, King Khalid University Hospital. ******* MB ChB, MSC, registrar, Anesthesia department, King Khalid University Hospital. Address Corespondence: Dr. R.A. Alsatli, Consultant Anesthetist, King Khalid University Hospital P.O.Box 7805(41), Riyadh 11472, KSA. 305
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patients who underwent creation of arteriovenous fistula. We retrieved the data concerning the age, sex, ASA class, and coexiting diseases. The patients were classified into three groups depending on the anesthetic technique received. G r o u p A (n = 48) patients received general anesthesia; group B (n = 39), patients received brachial plexus block and group C (n=77), patients received local infiltration anesthesia. Chi-square test was used to compare between the percentages among the different groups. The percentages of cardiac patients showed significant differences between groups A and B and also between groups A and C. There was a significant difference between the groups A and B also between the groups A and C but not between groups B and C concerning age. ASA classes were not significantly different among the groups. Among the t o t a l number of patients, 34 were diabetics and 75 patients were cardiac. Axillary brachial plexus block was complete in 70% of patients and incomplete in 27% and failed in 3% of patients. We conclude that chronic renal failure patients are at increased risk during anesthesia. We conclude that brachial plexus blockade or local anesthetic infiltration are good alternatives to general anesthesia in these patients undergoing creation of arteriovenous fistula. Age, ASA class and cardiac sfatus were the three determining factors for the choice of the anesthetic technique. Further multivariate prospective study are needed to confirm these results.
Introduction
Hemodialysis via creation of arteriovenous fistula (AVF) is an established form of therapy for patients with chronic renal failure (CRF). In addition to the initial fistula creation, fistula revisions and declotting procedures are frequently performed among those patients. Anesthetic implications in such patients are governed by the presence of risk factors such as hypertension, ischemic heart disease, chronic pulmonary disease, anemia, cachexia, coagulopathy, uremic encephalopathy, metabolic acidisis and/or hyperkalemia. This necessitates a meticulous approach in selection of the
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technique of anaesthesia which can be either general anesthesia, brachial plexus block (BPB) or infiltration of local anesthetic a t the site of surgery. Several studies discussed the risk factors, morbidity, mortality and anesthetic technique for creation of AVF. Solomonson et all reported morbidity and mortality rate in C R F patients thirty days after creation of AVF as 2.8%. Regarding the anesthetic management in C R F patients, Granshaw et a12 recommended the use of fentanyl as narcotic, atracurium for muscle relaxation if general lnesthesia is performed. Brachial plexus block (BPB) is commonly used to provide anesthesia in C R F patients for creation of A V F with a reported unsuccessful block rate of 2-3'/0~,~. The aim of the present sutdy is to compare between the different anesthetic care and outcome. To our knowledge this is the first such study conducted in a Saudi hospital.
Patients and Methods ,.
The charts of 164 C R F patients who underwent creation of AV fistula at King Khalid University Hospital in the period 19911996 were reviewed. Investigators retrieved data concerning age, sex, ASA, and coexisting diseases, such as diabetes mellitus (DM), hypertension (HTN) and ischemic heart disease (IHD). Other data retrieved were EKG, chest roentgenography (CXR), echocardiography and/or cardiac catheterization studies. Patients were classified into three groups depending on the anesthetic technique received: Group A (n=48), patients received general anesthesia (GA); Group B (n=39), patients received brachial plexus block (BPB) axillary approach; and in Group C (n=77), local anesthetic infiltration (LA) was done. All patients were assessed preoperativeIy. Elective cases were premedicated with Lorazepam at bedtime and 2 hours before surgery. Emergency cases received no premedication. In the operM.E.J.ANESTH 15 (3), 1999
ating theater, patients were connected t o EKG monitor, noninvasive blood pressure automated measurement, peripheral line was inserted in the non-operated arm and crystalloid infusion started. Oxygen saturation was monitored by pulse oximetry. In cardio-compromised patients, direct blood pressure and central venous presure monitoring were done. General anesthesia in Group A was achieved with thiopentone or propofol followed by atracurium which was given to facilitate endotracheal intubation and narcotics and fentanyl were used for analgesia. Anesthesia was maintained with isolfuran, N 2 0 / 0 2 mixture and incremental doses of atracurium and fentanyl. At the end of surgery residual muscle relaxation was antagonized by intravenous neostigmine and atropine in the usual routine doses. Brachial plexus block in Group B was performed either with the aid of electrical nerve stimulator or by elicitng parasthesia, also fascia1 click using short beveled needle was done. Local anesthetic used was either bupivacaine 0.5% or lignocaine 1 % or combination of both. Block was considered either complete or incomplete if narcotics and/or sedatives were given to achieve proper surgical analgesia. Continuous axillary BPB was performed in five patients to achieve neural blockade intraoperatively and analgesia postoperative where bupivacaine 0.125% (10ml) was administered hourly. To verify the catheter position a dye (Omnipaque) was injected into the axillary sheath through the catheter where the dye distribution confirmed the catheter position (Fig 1). The catheter was left in place for a maximum of two days then it was removed by the concerned anesthetist. In Group C patients, infiltration of local anesthetic at the site of surgery was performed by the surgeon where 10-15 m1 lignocaine 1% was given. Descriptive analysis of the obtained data was perfomed. Chisquare test was used to compare the percentages of the obtained data. A p;value < 0.05 was considered significant.
AKTERIOVENOUS FISTULA IN C R F
"F-
Fig.1: Dye distribution inside the axillary sheath.
Results
164 patients were included in the study. The mean age for groups A , B and C were 34, 52 and 48 years respectively (range 13-95). In group A, 37 patients were ASA I11 and 11 were ASA TV. In group B two patients were ASA I1 while 25 and 12 patients were ASA I11 and IV respectively. In group C none M.E.J. ANESTH 15 (3), 1999
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of the patients was ASA I & I1 but 53 and 24 patient were ASA I11 and IV respectively. Among the total number of patients in the three groups 34 patients had diabetes mellitus (i.e. 20%) and 75 patients were found to have cardiac disease (ischemic heart disease, myocardial infarction, or heart failure). Fifteen patients were cardiac in group A, but 22 and 38 patients were cardiac in groups B and C respectively. Axillary BPB was complete in 70% of the patients and incomplete in 27% of the patients while failure of block occurred in 3 % of the patients in this group where general anesthesia was given. Descriptive analysis of the data obtained for the three groups of patients is presented in table 1. Comparing the percentages of cardiac patients using Chi- squared test showed a significant difference between groups A and B as well as between groups A and C (p
