Epidural anesthesia using a 0 , 75 % ropivacaine and subarachnoid anesthesia with a 0 , 5 % bupivacaine associated or not with clonidine in hemorroidectomies 1 Anestesia peridural com ropivacaína a 0 , 75 % e anestesia subaracnóidea com bupivacaína a 0 , 5 % associadas ou não à clonidina em hemorroi

Purpose: To study the safety and efficiency of two anesthetic blockages in hemorroidectomy and the effect of clonidine on analgesia. Methods: 80 patients were studied, randomly divided into four groups: l (n=19)peridural with a 0,75% ropivacaine; 2 (n=21)-peridural with a 0,75% ropivacaine and 150 μg of clonidine; 3 (n=19)subarachnoid with a 0,5% bupivacaine; 4 (n=21)subarachnoid with a 0,5% bupivacaine and 50 μg of clonidine. The intensity of pain was evaluated by the visual analogical scale 8, 12 and 24 hours after surgery. The use of vasoconstrictors on the transoperatory and the amount of analgesics within the 24 hours were registered. Results: The intensity of pain, 8 hours after surgery, was lesser on group 4, and much lesser on group 4 comparing with groups 1 and 2, 12 hours (p=0,022; p=0,001) and 24 hours (p=0,03; p=0,003). The frequency of vasoconstrictors usage on the transoperatory and the analgesics on the post-operatory showed no difference among the groups. There were no anesthetic complications. Conclusions: The subarachnoid anesthesia with a 0,5% bupivacaine with clonidine, showed better analgesia comparing with the peridural anesthesia with a 0,75% ropivacaine with or without clonidine, however all were safe and efficient. The clonidine aided on the decreasing of pain when subarachnoid anesthesia was used.


Introduction
The pain after hemorroidectomy, despite the advance on the analgesia field, is a reality.It can vary from intensity and frequency.Many surgical and anesthetic measures have been used to avoid or to lessen such.It is up to the anesthesiologist to adopt some measures recommending the use of certain medicaments [1][2][3][4][5][6][7][8][9][10] , preemptive analgesia [11][12][13][14][15] .Botulinic toxin injection can also be used in the internal sphincter 16 micronized fractions of flavonoids 17 and the transcutaneous electrical stimulation 18 .
Other analgesia trials have been made with the adding of morphine 19,20 and clonidine on anesthetic blockages.In hemorroidectomy, under caudal blockage, the clonidine, mixed with bupivacaine, lidocaine and epinefrine, increased the time of analgesia, more than the saline solution added to the same mixture 21 .In proctologic surgeries, especially hemorroidectomy, the clonidine associated with lidocaine and fentanil, in subarachnoid anesthesia, prolonged the time of analgesia, lessened the intensity of pain, with minimum side effects 22 .The clonidine associated with ropivacaine, improved the post-operatory analgesia when epidural anesthesia was used in surgeries performed on the lower part of abdomen 23 .Though, clonidine did not improve the analgesia when used: a-by a catheter near the infraclavicular nerve, in orthopedic surgery of upper limb 24 ; b-on intratecal space in surgeries to remove hip and knee 25 ; c-on interescalenic space, in shoulder surgeries 26 .
Considering that the analgesic efficiency of clonidine is contradictory, and that peridural anesthesia with a 0,75% ropivacaine and that subarachnoid anesthesia with a 0,5% bupivacaine have often been used by our anesthesiologists, and that there are no studies that compare these two anesthetic techniques, we put together this paper with the following objectives: Identify on the immediate post-operatory of patients undergone hemorroidectomy, the analgesic efficiency and the safety of peridural with a 0,75% ropivacaine, associated or not with clonidine and subarachnoid anesthesia with a 0,5% hyperbaric bupivacaine associated or not with clonidine, and to compare the results from these anesthetic techniques.

Methods
This paper was approved by the Committee of Research Ethics of the Federal University of Minas Gerais, as per document number ETIC 0478/05.All the patients involved, signed a Term of Previous Informed Consent.
80 patients both men and women, were operated, ages between 20 and 70, ASA 1 or 2, with hemorrhoids of third and fourth degrees (Table 1).The following criteria were adopted to select the patients: 1-Exclusion Criterion: patients suffering from lesion or fistula, with serious heart and respiratory disease, diabetes, with alter psquism, chronic and painful disorder; frequent users of analgesics; and the ones allergic to any analgesic drug; 2-Inclusion Criterion: patients with no surgical counterindication, with hemorrhoids of third and fourth degrees.
On patients ready for surgery, the colon was prepared using a bottle of enema (sodium phosphate monobasic H 2 0 16 g, and sodium phosphate dibasic H 2 0 6g), administered via rectum 10 hours before surgery.Midazolan, 7,5 mg was used as preanesthetic sublingual medication one hour before surgery.A vein was punched from the upper limb (back of hand or anterior of forearm), using an I.V catheter 20 to infuse saline solution and medicaments.All the patients were monitored using ECG, oximetry of pulse and non-invasive arterial pressure, with values written down on anesthetic file.
The epidural puncture was performed using a Tuohy 15G needle, on the space between L3-L4, with patients sitting down.The drugs were injected in the peridural space, volume of 15 mL, and velocity of approximately 1 mL/second.The unilateral spinal puncture was performed with a 27 G needle on the space between L3-L4, using a injector to make the puncture easier and to injection of medication, proved to be efficient against the risk of headache after surgery.The velocity of solution injection was about 1mL/15 second.After about 5 minutes, a rectum touch was performed by the surgeon in order to evaluate the degree of sphincter relaxing.A value was attributed from 0-10 according with the degree of relaxing (Table 2).The hemorroidectomy technique was performed only by the surgeon on duty, the semiclosed technique was used (Milligan Morgan technique associated with Fergusson).
The safety of anesthetic techniques was evaluated by monitoring the transoperatory arterial pressure, pulse, Sat02 and breathing, besides the electrocardiographic tracing.Each patient whose blood pressure dropped beyond 20% from the initial value, were treated with vasoconstrictors.The vital signals were also evaluated 20 minutes after surgery, four hours, eight hours, 12 hours, and the usual 24 hours and/or in other situations when necessary.
The analgesic efficiency of anesthetic techniques was evaluated by intensity of pain and by consumption of analgesics.The intensity of post-operatory pain was evaluated by a scale of visual analogy (EAV) 8, 12 and 24 hours after beginning the anesthesia, or at other time when it was necessary.On this scale, zero represents the absence of pain, and 10, the presence of intense pain (unbearable).The frequency of analgesic usage within 24 hours was also calculated.All patients had their data written down on a special file.After hemorroidectomy, the patients received endovenous, 100 mg cetoprofene and 1g dipirone and were strictly observed on post-anesthetic recovery by a professional that didn´t participate on the procedure, however, accompanied them during a 24-hour period, after surgery was finished.
The following statistics were used: a-Descriptive Statistics to calculate the arithmetic average (A.A) and (S.D) standard deviation of variables: age, height, weight, BMI, surgical duration, EAV-8 hours, EAV-12 hours, EAV-24 hours; and the variable frequency when necessary; b-Correlation test of Spearman to correlate the BMI, age, operation duration with the EAV; c-chi-squared statistic to compare the number of male patients with the female ones; d-Fisher exact statistics to compare the frequency of patients that used analgesic and vasoconstrictor comparing with the ones that didn´t use such; e-Kruskal-Wallis test to compare the surgical duration, BMI, age, the EAV (8-12-24 hours) and the sphincter relaxing among the four groups b; f-Doon Multiple comparison (post-hoc) when the Kruskal Wallis test showed significance.A p<0,05 value was considered statistically significant.

Results
The hemorroidectomy procedures were performed with no difficulties, an average time of 21±8,1 minutes, and there were no post-operatory complications related with this operation.
There was no significant difference between the number of male or female patients, average age, BMI and operation average duration on the four groups (p>0.05).
There was no correlation between intensity of pain and BMI (p> 0.05).
No correlation between operation duration and intensity of pain was found, except on patients undergone peridural anesthesia without clonidine, after 8 and 24 hours (p<0.05).The pain was more intense on patients that had a more prolonged surgery period.There was no correlation between intensity of pain at 8, 12 and 24 hours and age of patient (p>0.05).
The rachianesthesia and peridural anesthesia were performed without any incident.Both associated or not with clonidine, proved to be safe.The monitoring of non-invasive arterial pressure, determined by Riva-Rocci method, the electrocardioscopy on derivations D II e V I , used also to measure the cardio-frequency, and the pulse oximetry to measure the hemoglobin saturation (SpO 2 ) didn´t suffer unexpected alterations.There was no significant statistical difference among the groups on the frequency of vasoconstrictor usage on the transoperatory (p>0.05)(Table 1).
Both analgesic techniques were efficient to treat pain.Though, the intensity of pain 8 hours after hemorroidectomy had no difference among the groups (Figure 1).The intensity of pain, 12 hours after hemorroidectomy, was lesser on the group of patients submitted to rachianesthesia with clonidine comparing with peridural without clonidine (p<0.05) and peridural with clonidine (p<0.05) and had no difference from rachianesthesia without clonidine (p>0,05) (Figure 1).The intensity of pain 24 hours after surgery was lesser on patients submitted to rachianesthesia with clonidine, unlike patients submitted to peridural with clonidine (p< 0.05) and peridural without clonidine (p<0.05);there was no difference on the intensity of pain on groups 3 and 4 (Figure 1).There was no difference on consumption of analgesics among the four groups (p>0.05) on postoperative (Table 3).The patients submitted to rachianesthesia presented better muscle relaxing, therefore making the surgery easier (Table 2).

Discussion
The semiclosed hemorroidectomy technique was used on all patients; scalpel with removable blades and conventional surgical material (nippers, scissors); electrical scalpel was used to section the anal mucosa, and the surgeries were performed by only one surgeon.It´s important to mention that on this experiment, there was no significant statistical difference in age, gender, and duration of operation on the different groups.This, to a certain extend, allowed the team to control variables that could interfere on the results and make comparisons among the groups, because the intention was to simply verify the effect of variable "anesthesia associated or not with clonidine", on post-operatory pain.
The analyses from the results of this work, showed that the subarachnoid anesthesia with a 0,5% bupivacaine and the epidural anesthesia with a 0,75% ropivacaine with or without clonidine were both safe.The hemodynamic alterations that happened during the blockage were absolutely predictable and the use of vasoconstrictors didn´t interfere among the groups (p>0.05).It´s important to point out that clonidine causes hypotension and bradycardia because it activates the 2 -pre-synaptic adrenoceptors, on peripheric nerve termination, inhibiting the exocytose of noradrenaline 35 .Besides that, the hypotension is caused by the activation of the center of vasomotor on CNS, with decreasing of sympathetic efflux and reducing the circulating catecholamine with potential parasympath nerve activity, decreasing this way, the arterial pressure 36 .But, clonidine caused vasoconstriction because it activated the post-synaptic receptors on the flat musculature of arteries and veins 36 .
When the intensity of pain was compared among the groups, eight hours after hemorroidectomy, we observe that the pain was less intensive when using rachianesthesia with clonidine other than peridural without clonidine and peridural with clonidine.This can be associated with the major muscular relaxing caused by the rachianesthesia and by a possible analgesic effect from clonidine that was present at that period.The pain was also less intense in patients undergone rachianesthesia with clonidine comparing with peridural with clonidine (p<0.05)peridural without clonidine (p< 0,05), 12 hours after surgery.This happened 24 hours after hemorroidectomy, when this kind of anesthesia was compared with peridural with clonidine (p<0.05), and peridural without clonidine (p<0.05).Although no difference on the intensity of pain between the two kinds of rachianesthesia was shown.Besides that, there was no significant statistical difference on the frequency when using the analgesic among the four groups (p>0,05).This shows that the rachianesthesia is more efficient than the peridural and that clonidine helped decreasing the post-operatory pain when associated with rachianesthesia.The fact that rachianesthesia produces good muscular relaxing and consequently making the operation easier, producing less trauma could justify the less intensity of pain.In fact, the subarachnoid anesthesia produced more sphincter relaxing than the peridural anesthesia (Table 2).
We observed that the clonidine associated with ropivacaine on peridural anesthesia, did not interfere on pain, 8 and 12 hours after surgery.On rachianesthesia the clonidine helped reducing pain 8, 12 and 24 hours after surgery.We can observe that when the comparison of value between the groups that used clonidine on rachianesthesia and the ones that didn´t was made.
The clonidine used on the blockages, shows controversial results.On hemorroidectomy, under caudal blockage, it was associated with a mixture of bupivacaine, lidocaine and epinefrine, caused more prolonged analgesia than the saline solution added to such mixture 21 .On proctologic surgeries, especially hemorroidectomy, the clonidine associated with lidocaine and fentanil, on subarachnoid anesthesia, prolonged the time of analgesia, reducing the intensity of pain, with minimum side effects 22 .Both, clonidine and ropivacaine, improved the postoperatory analgesia, when used under different blockages and types of surgery [23][24][25]32 . Som studies, though, claim that this drug does not improve analgesia when also taken by different ways and in different types of surgery [24][25][26] .This study showed that clonidine helped decreasing pain when used on rachianesthesia, although on this anesthesia, the dosage had been smaller than on peridural anesthesia.This drug on the subarachnoid space produced more intense and selective effects than the ones observed with similar dosage on epidural space 33 .It´s important to emphasize that the dosage and via of administration of clonidine, interfered on its analgesic action 36 .

Conclusion
The subarachnoid anesthesia with a 0,5% bupivacaine with clonidine, showed better analgesia than epidural anesthesia with a 0,75% ropivacaine with or without clonidine, though all proved to be safe and efficient.

FIGURE 1 -
FIGURE 1 -Intensity of pain (EAV) 8, 12 and 24 hours after hemorroidectomy among the four groups of patients: 1-.Peridural Anesthesia without clonidine, 2-Peridural Anesthesia with clonidine; 3-Rachianesthesia without clonidine; 4-Rachianesthesia with clonidine.The column represents the average of variable; the straight segment over the column represents the standard-deviation.* or †-significant between groups 2 and 4 and between groups 1 and 4. Kruskal Wallis