Does wound in fi ltration of tramadol reduce postoperative pain in laparoscopic or open herniorrhaphy ?

Introduction: The laparoscopic approach may be associated with more postoperative pain initially. The aim of this study was to evaluate the effects of administered tramadol at wound closure on postoperative pain and analgesic requirements under spinal anesthesia in laparoscopic inguinal herniorrhaphy (LH) or tension free open inguinal herniorrhaphy (TFOH). Methods: Twenty patients were randomly divided into two groups (n= 10 in each) as LH or TFOH. Patients received infi ltration of 200 mg tramadol with 40 mL of 0.9% saline solution at wound closure procedure. Postoperative pain was assessed with a Visual Analog Scale (VAS) at 3, 6, 12, and 24 hours postoperatively. Additional requirements of tramadol for postoperative pain releif were registered. Results: VAS scores at postoperative 12 and 24 hours were signifi cantly higher according to 3rd hour VAS scores in both groups. The VAS scores at 12 hours after operation signifi cantly lower in LH group than in TFOH group (1.5 ± 0.97 vs 5.1 ± 0.99). Additional requirements of tramadol for postoperative pain releif were signifi cantly lower in LH group. Conclusion: We conclude that wound infi ltration of 200 mg tramadol reduce postoperative pain in LH group. © 2012 All rights reserved


Introduction
Pain aft er laparoscopic surgery may vary in quality and localization and is reported in several studies to be incisional, intraabdominal, or referred (1).Th e etiology is complex, including damage to abdominal wall structures, the induction of visceral trauma and infl ammation and peritoneal irritation because of CO2 entrapment beneath the hemi diaphragms.Pain aft er laparoscopic procedure is signifi cantly less and shorter than that caused by the same surgical procedure made possible by open surgery (2).Compared with open procedures, laparoscopic surgery, a minimally invasive technique, is associated with reduced surgical trauma (3).Anti-infl ammatory drugs decrease postoperative pain as local anesthetics and opioids when administered at the surgical site at time of wound closure.Tramodol is a centrally acting synthetic analgesic with μ-opioid receptor agonist activity.Infi ltration of tramadol into the surgical wound reduces postoperative pain with very few side eff ects (4).Patients benefi t from laparoscopic extraperitoneal hernia repair because this allows earlier mobilization than the more classical open surgical approach (5).Laparoscopic inguinal herniorrhaphy (LH) provides distinct advantages over open herniorrhaphy and it is the treatment of choice for many patients.LH is associated with less pain and disability without increasing mortality or overall morbidity (6)(7)(8).Although the eff ect of wound infi ltration of tramadol following LH provides better postoperative analgesia than open herni-orrhaphy, this issue is not well documented yet.Th e aim of this study was to evaluate postoperative pain relief eff ects and analgesic requirements of locally administered tramadol aft er LH and tension free open herniorrhaphy (TFOH) under spinal anesthesia.

Methods
Twenty ASA physical status I or II patients were randomized for elective unilateral either LH or TFOH (n=10 in each).Informed consent was obtained from each patient.Patients were evaluated as primary inguinal hernia type II-a,b and III-a according to Nyhus Classiffi cation.Patients with renal disease, active peptic ulceration, a history of drug or alcohol abuse, chronic pain states, or daily intake of non-steroidal anti-infl ammatory drugs or opioids were excluded from the study.Any kind of complications were explained to all of the patients and informed consent was provided.All patients were instructed preoperatively about the use of a visual analog pain scale (VAS) (0= no pain to 10= excruciating pain).Th e patients didn't receive any analgesic premedication.Age (year), height (cm) and weights (kg) were recorded and all patients had received IV saline infusion (0.09% NaCl, 10 mL kg-1) in the operating room about 20 min before spinal anesthesia.Standard monitors were included an electrocardiogram, non-invasive blood pressure device, and pulse oxymetry.Oxygen was administered to all patients via nasal catheters at rate 2 mL/min.Spinal anesthesia was made with a 26 G Quincke point needle in the lateral position at the L4-L5 interspaces.Aft er clear, free fl ow of cerebrospinal fl uid was obtained, 3 mL heavy 0.5% bupivacaine (*Marcaine heavy, Astra Zeneca, England) was administered intratecally.Patients were then placed with a supine horizontal position until the end of the study.Any decrease or increase in baseline systolic blood pressure of more than 20% was treated and excluded from the study.When a bradycardia or tachycardia occurs then atropine 0.5 mg was given.Data were recorded on a chart recorder.No opioids were given during the operation.Th e extra peritoneal laparoscopic hernia repairs were performed by the same surgeon.A subumblical incision was made and the rectus sheath was retracted to create a plane between the pos-terior aspect of the rectus muscle and the peritoneum.A space-maker balloon trochar apparatus was then introduced and infl ated with isotonic sodium chloride solution (1000 mL) before defl ation.Th e dissection exposed the hernial defect and allowed placement of the mesh.At the end of surgical procedure, Tramadol 200 mg in 40 mL of 0.9% saline was injected to the wound locally by the surgeon.Th e patients were placed in a 30o sitting position to keep the injected volume in the ilioinguinal dependent area of the fascial plane.Data collected that included to time intervals (minute) duration of spinal anesthesia (bupivacain injection to loss of sensorial level of L2) and duration of surgery (incision to end of surgery).Patients were transferred to the recovery room and observed by nursing staff and have not received any other analgesics during the study.Postoperative pain was assessed by using a VAS during unassisted mobilization at 3, 6, 12 and 24 hour aft er operation.When VAS value was ≥ 3, tramadol was given intramuscularly for postoperative analgesia and total amount of tramadol were documented for each patient.Postoperative complications included nausea and vomiting were also noted.

Statistical analysis
Th e results were expressed as mean values ± standard deviation.Mann-Whitney-U was used to compare VAS scores and total amounts of tramadol as additional analgesic postoperatively for each patient between two groups.Friedman test and Wilcoxon test were used for repeated and related measures.P values less than 0.05 was considered as statistically signifi cant.Th e study was conducted in accordance with the ethical standards of the Helsinki Declaration of 1975.

Results
Age, height, weight, duration of anesthesia and surgery were similar in two groups (Table 1).VAS scores on postoperative periods in the groups and levels of statistical signifi cance changes according to 3th hour VAS scores were shown in Table 2. VAS scores at postoperative 12 and 24 hours were signifi cantly higher in both groups.Th e signifi cant is greater in TFOH group.Th e VAS scores were reduced signifi cantly in LH group than in TFOH group at 12 hours aft er operation (1.5 ± 0.97 and 5.1 ± 0.99) (Table 2).Fift een patients received additional tramadol postoperatively.Th ere was statistically significant diff erence between groups for the time to the fi rst request for tramadol between LH group and TFOH group; the patients in the TFOH groups needed additional tramadol earlier than the patients in the LH group.Tramadol requirements were signifi cantly lower in LH group while 5 patients never received and 5 patients received only once aft er operation (Table 3).Th e highest frequency of postoperative nausea and vomiting (PONV) coincided in early postoperative period.Th ere were not statistically signifi cant diff erences between groups in means of PONV (Table 4).

Discussion
Laparoscopic surgery, compared with open procedures, may be associated with diminished surgical trauma response and shortened recovery time; early postoperative pain aft er laporoscopic procedure which is a frequent complaint (9).Saff et al showed that laparoscopic extraperitoneal hernia repair with bupivacaine resulted in a lack of pain-relieving effi cacy (5).Th ere are diff erent reasons for pain in extraperitoneal laparoscopic hernia repair based on the aff erent source of pain signals.Th ere is a signifi cant contribution of visceral pain fi bers that are more diff use in distribution and innervation (5).Th ese fi bers are more refractory to blockade with local anesthetics and nonsteroidal anti-infl ammatory drugs than somatic fi bers (2,10).Th e latter are related to stimulation of neuronal serotonin release and inhibition of presynaptic reuptake of norephinephrine and serotonin (11).Tramadol is a synthetic and centrally acting analgesic.It has both opioid and non-opioid properties.Tramadol has been shown to have a similar potent eff ect on pain as morphin (12).In clinical trials, tramadol has not displayed the serious side eff ects typically seen with the use of opioid analgesics or non-steroidal anti-infl ammatory drugs (13)(14)(15).Direct infi ltration into the wound is a common form of postoperative analgesia in the surgery because of reduced side eff ects of the drugs on cardiovascular and central nervous system (16).Relieving pain in patients with herniorrhaphy can be problematic.Inadequate analgesia may delay discharge or pro-  ) 0.429 12 1.5 ± 0.97 (2 [0-3]) 0.020 5.1 ± 0.99 (5 [4-7]) 0.005 24 5 ± 1.33 (4.5 [3][4][5][6]) 0.005 6.4 ± 1.34 (6 [5-9]) 0.005   Th e recommended systemic dose of tramadol for postoperative pain is 50 mg intramuscular injection.Morphine produces a prolonged postoperative analgesia, but is associated with major side eff ects such as postoperative nausea and vomiting, in particular the potential of delayed respiratory depression (15).Clonidine, an alpha 2 adrenergic agonist, has been shown to potentate postoperative analgesia.Although, clonidine improved the effi cacy of analgesia, it was associated with prolonged sedation.Of all the agents used, wound infi ltration of tramadol seems to show promise because of the absence of the side eff ects (18).Inadequate pain treatment causes discom-fort, prevents sleep and thereby contributes to postoperative fatigue, delays discharge, and limits activity, prolong recovery period, and may induce nausea and vomiting.Th ere were not statistically signifi cant diff erences between groups in means of PONV in this study also.Yndgaard S. et al., have been shown that analgesic eff ect of subfascial infi ltration with local analgesic was observed on postoperative pain aft er herniorrhaphy.Th erefore, using tramadol may provide better eff ect is the postoperative pain and less side eff ects (19).Th e results of the VAS score indicate a negligible eff ect with a signifi cant level for longlasting period postoperatively when wound infi ltration of tramadol was used in LH group.Th e effect of tramadol is clear: it lasts for a longer period and is evident during the mobilization.At postoperative 12 and 24 hour, the median VAS score in LH group decreased than TFOH group.Most of the patients in the group had not needed analgesic requirements but only a few patients was given analgesic drug for pain and with low VAS scores remained in the group.Th e nausea, vomiting and sedation, which are frequently associated with the administration of parenteral opioids and similar drugs such as tramadol.But, wound infi ltration of these drugs has been found more suitable for use in a day care setting and postoperative analgesia (20).

Conclusıon
We conclude that wound infi ltration of 200 mg tramadol provides more long lasting eff ect for pain management in LH group without respiratory depression, PONV or other side eff ects

Confl ict of interest
Authors declare no confl ict of interest.

TABLE 1 .
Patients demographic data and duration of anesthesia and surgery in two groups

TABLE 2 .
Visual analog scale (VAS) scores on postoperative periods in two groups and levels of statistical signifi cance changes according to 3 th hour VAS scores.Data was shown as median [min -max] ± standard deviation.p † : levels of statistical signifi cance changes according to 3 th hour (Wilcoxon signed ranks).

TABLE 3 .
Tramadol requirements in two groups

TABLE 4 .
(6)sea and vomitingLH; laparoscopic herniorrhaphy group, TFOH; tension free open herniorrhaphy group long hospital stay(6).Concerns over the safety of analgesics oft en lead physicians to use small doses of these drugs with consequent sacrifi ces in efficacy; the respiratory depression, together with the prevalent nausea and vomiting, caused by opioids.