|Year : 2014 | Volume
| Issue : 3 | Page : 441-443
Does selective sympathetic block in live donor affect renal resistivity index and urine output in recipient kidney?
Z Gomaa1, Hazem Aboftooh2, T Haytham3
1 Department of Anesthesia, , Cairo University, Cairo, Egypt
2 Department of Urosurgery, Cairo University, Cairo, Egypt
3 Department of Nephrology Department, Wadi Elneel Hospital, Cairo, Egypt
|Date of Submission||01-Feb-2014|
|Date of Acceptance||19-Aug-2014|
|Date of Web Publication||27-Aug-2014|
Department of Anesthesia, Cairo University, Cairo
Source of Support: None, Conflict of Interest: None
The intrarenal resistive index (RI) is routinely measured in many renal transplantation centers for assessment of postoperative renal function. The present study dealt with the effect of chemical sympatholytics by blocking the sympathetic supply to the kidney on urine output and renal RI.
Patients and methods
A total of 50 patients were enrolled in this prospective, randomized study. The donors were divided into two groups: group P in which Papavarine was infiltrated by surgeon under complete aseptic technique around the renal artery and the other group (group B) in which bupivacaine was infiltrated by surgeon under complete aseptic technique around the renal vessels. Urine output was monitored and calculated over 6 h from renal transplantation. Renal RI was recorded over 6 h after transplantation of live donor kidney.
There was significant increase in the urine output collected over 6 h postoperative in the Bupivacaine group (1115.2 ml) (P = 0.0001) in comparison with the Papavarine group (823.6 ml). There was a significant decrease in renal arterial RI of the Papaverine group (0.66) (P < 0.0001) compared with the Bupivacaine group (0.79).
Bupivacaine injection around the renal vessels in donor might be of benefit for recipient transplanted kidney to improve urine output.
Keywords: renal resistivity index, sympathetic block, transplantation
|How to cite this article:|
Gomaa Z, Aboftooh H, Haytham T. Does selective sympathetic block in live donor affect renal resistivity index and urine output in recipient kidney?. Ain-Shams J Anaesthesiol 2014;7:441-3
|How to cite this URL:|
Gomaa Z, Aboftooh H, Haytham T. Does selective sympathetic block in live donor affect renal resistivity index and urine output in recipient kidney?. Ain-Shams J Anaesthesiol [serial online] 2014 [cited 2021 Oct 24];7:441-3. Available from: http://www.asja.eg.net/text.asp?2014/7/3/441/139591
| Introduction|| |
Renal transplantation is a worldwide practice. A lot of cases are performed every day. The most important issue is to transfer a healthy kidney from the donor to the recipient. The renal plexus is formed by filaments from the celiac ganglia and plexus, aorticorenal ganglia, lower thoracic splanchnic nerves and first lumbar splanchnic nerve, and aortic plexus. The nerves from these sources, 15 or 20 in number, have a few ganglia developed upon them; it enters the kidneys on arterial branches to supply the vessels, renal glomerulus, and tubules with branches to the ureteric plexus . The challenge is met with the reduction in function, which may be the mirror image of intraparenchymal arteriolar vasoconstriction and decreases the glomerular filtration rate and urine output. Sympathetic block has been used extensively to increase vascularity in the upper limb and lower limb ischemia in clinical practice. The responses to sympathomimetics in grafted kidney of rats were shifted toward flow reduction (i.e. enhanced vasoconstriction by stimulation of a-adrenoceptors and blunted vasodilatation by stimulation of b-adrenoceptors). This functional impairment was recovered in a time-dependent manner. In addition, the hemodynamic autoregulation system in the kidney deteriorated following transplantation or denervation . The arterial resistivity index (also called resistance index, abbreviated as RI), developed by Launder Pourcelot, is a measure of pulsatile blood flow that reflects the resistance to blood flow caused by microvascular bed distal to the site of measurement. The RI is altered not only by vascular resistance alone, but also by the combination of vascular resistance and vascular compliance .
The intrarenal RI is routinely measured in many renal transplantation centers for assessment. The present study dealt with the effect of chemical sympatholytic by blocking the sympathetic supply to the kidney on urine output and renal RI (peak systolic velocity-minimal diastolic velocity/peak systolic velocity of renal allograft). The RI is a ratio of peak systolic and end diastolic velocity, derived from the Doppler spectrum of any vessel. Initially, this index was introduced by Pourcelot .
| Patients and methods|| |
After approval from Research and Ethics Committee and written informed consents from all patients, 50 patients were enrolled in this prospective, randomized study, which was conducted in Wadi Elneel Hospital. Patients were prepared for renal transplantation with their donors. The donors were selected properly; preoperative assessments were performed. All were medically free (ASA 1) and were prepared for laparoscopic nephrectomy. The donors were divided into two groups: group P in which Papavarine 2 mg in 10 ml volume was infiltrated by surgeon around the renal vessels and the other group (group B) in which bupivacaine 0.25% in 10 ml volume was infiltrated by surgeon under complete aseptic technique around the renal vessels. All donors were premedicated with 0.2 mg/kg diazepam administrated orally 90 min before anesthesia induction. On arrival to the operating room, standard anesthetic technique was conducted by consultant anesthesiologist. After fixation of standard monitoring and preoxygenation for 3 min, anesthesia was induced with fentanyl 2 µg/kg and propofol 2.5 mg/kg. Neuromuscular block was achieved with cisatracurium 0.15 mg/kg. Tracheal intubation was performed when maximum neuromuscular blocking effect assessed by the train-of-four count at the adductor pollicis was achieved. Folly catheter was inserted and patient was positioned in lateral kidney position. All donors received the same volume of lactated Ringer's solution intraoperatively. All procedures were performed by the same surgeon; before dissection, the study drugs were given blindly for the surgeon but known to the anesthetist in 10 ml volume Papavarine (2 mg) for the Papavarine group and Bupivacaine 10 ml (0.25%) for the bupivacaine group. All the procedures including the irrigation and the conservative measures of the kidney were performed in the same manner for both groups. Anesthesia was maintained with sevoflurane (1-2% end-tidal) and 30% oxygen in air, supplemented by boluses of fentanyl (1-2 µg/kg). At the end of surgery, neuromuscular block was reversed with neostigmine 0.05 mg/kg and atropine 0.025 mg/kg, and the pharynx was gently suctioned. Before tracheal extubation, patients breathed 100% oxygen for 5 min and the ETT was removed as soon as all of the following criteria were met: full reversal of neuromuscular block (ulnar nerve T4/T1 ratio = 1); spontaneous breathing; and the ability to follow verbal commands (hand grip or eye opening) or else demonstrate purposeful unilateral movement (attempting self-extubation). Recipient patients were anesthetized by the same standard protocol with central line insertion, arterial cannulation, using the same standard drugs for induction and maintenance, keeping the central venous pressure (CVP) in all cases around 10-15 cmH 2 O. Methylprednisolone 1 g was administered intravenously to all recipients after declamping of renal artery.
Monitoring of the vital sign (blood pressure, heart rate) and CVP was performed intraoperatively every 15 min. Urine output was monitored and calculated after 6 h from renal transplantation. Blood gases were kept controlled tightly. Renal RI is a sonographic index to assess for renal arterial tree, and it equals the peak systolic velocity-minimal diastolic velocity/peak systolic velocity; it was recorded 6 h after surgery with normal value ranging 0.6-0.7 [ 5].
Sample size was 50 on the basis of the primary outcome of the study, which is the effect of sympathetic block on urine output in recipient kidney.
Data were analyzed using Statistical Software version 7.0 for Windows (Statsoft Inc.). Unpaired Student's t-test was used to compare the parametric values of the two groups; demographic data, sex, and other ratios data were analyzed using Fisher's exact or the c2 -tests. The Mann-Whitney U-tests were used for nonparametric data. Statistical significance was defined as P value less than 0.05.
| Results|| |
Fifty patients participated in our study and none was excluded. There were no statistically significant differences between the recipients group regarding demographic data and hemodynamic parameters (blood pressures, pulse, and CVP) [Table 1].
There was a significant increase in the urine output collected over 6 h postoperatively in the Bupivacaine group (1115.2 ml) (P = 0.0001) in comparison with the Papavarine group (823.6 ml) [Table 1]. There was a significant decrease in renal arterial RI of the Papaverine group (0.66) (P < 0.0001) compared with the Bupivacaine group (0.79) [Table 1].
The two donor groups showed no significant differences in demographic data [Table 2]. None of the donors had any complication from the used drugs in the study.
| Discussion|| |
The transplanted kidney is a denervated organ; the function is extremely dependent on maintenance of blood pressure to maintain more hydrostatic pressure for glomerular filtration; hence, any arteriolar spasm will decrease urine output. In the present study, attempt was performed at least in the range of half-life of drugs used to perform arteriolar dilatation.
This is the first prospective, randomized study in which bupivacaine was injected perivascularly to compare the outcome in renal transplantation patients. Bupivacaine was utilized for stellate block to increase vascularity in the upper limb and in lumbar sympathetic block to relieve lower limb ischemia. From this finding, bupivacaine was used for selective sympathetic block for the donor kidney.
The RI as a test carried good sensitivity in many studies. In this study, it was concluded that not only fluids given to the donor kidney to maintain a good urine output and rigid kidney, but also intraparenchymal vasodilatation was needed to give a better response. Many researchers studied the effect of epidural block in donors as adjuvant to anesthetic technique, but none mentioned its effect on the graft function.
Several studies have shown that normal mean RI is ˜0.6. The largest series to date (58 patients) reported a mean (ISD) RI of 0.6 ± 0.01 for patients without pre-existing renal disease .
Multiple researchers have since documented the lack of specificity of an elevated RI after renal transplantation. Although RI analysis is not helpful in differentiating the typical causes of transplant rejection, it is still useful for potentially identifying vascular complications associated with transplantation .
In many reports, the term RI and renal vascular resistance are used interchangeably, although the relationship between these factors and other potentially confounding variables has, generally, not been considered.
Morita and Yamanashi  studied the effect of sympathomimetics in the rat transplanted and denervated kidney through injection of bolus of dopamine 50 μg/kg and continuous infusion of 60 μg/min phenylephrine; thereafter, using a laser Doppler flow meter, renal blood flow (RBF) was evaluated. They found that, in grafted denervated kidney, the dopamine-induced decrease in RBF mediated by a-adrenoceptors was markedly enhanced, whereas the increase in RBF mediated by an action of dopamine on b-adrenoceptors was blunted. The effects of the post-transplant period on vascular responses to dopamine were significant but not completely synchronized with the native kidney, and, in addition, the hemodynamic autoregulation system in the kidney deteriorated following transplantation or denervation. In the present study, sympathetic blockade might be responsible for the significant increase in RI and increase in urine output in the bupivacaine group, but nothing was conclusive to the detailed pathogenesis in renal parenchyma. Further studies in a wider scale are needed to ensure such starting finding in otherwise new method.
| Conclusion|| |
Bupivacaine injection around the renal vessels in donor might be of benefit for recipient transplanted kidney to increase RBF.
| Acknowledgements|| |
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[Table 1], [Table 2]