Combined ilioinguinal blockade and local infiltration anaesthesia for groin hernia repair—a double-blind randomized study

F. H. Andersen1, K. Nielsen2 and H. Kehlet3,*

1 Surgical Clinic Charlottenlund, Copenhagen, Denmark. 2 Surgical Clinic, Hvidovre, Copenhagen, Denmark. 3 Section of Surgical Pathophysiology, Juliane Marie Center 4074, Rigshospitalet, Copenhagen, Denmark

* Corresponding author. E-mail: henrik.kehlet{at}rh.dk

Accepted for publication November 2, 2004.


    Abstract
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 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Background. Local infiltration anaesthesia for inguinal hernia repair is cost-effective, but fear of intra-operative pain may hinder its widespread use. It is unknown whether a combined ilioinguinal blockade and local infiltration anaesthesia improves intra-operative analgesia.

Methods. We performed a double-blind randomized study in 160 patients undergoing inguinal hernia mesh repair under local infiltration anaesthesia with or without additional ilioinguinal blockade. Intra-operative pain and pain at 24 and 48 h postoperatively and analgesic requirements (acetaminophen, ibuprofen, and tramadol) were assessed.

Results. Median intra-operative pain scores were reduced (P=0.02) from 13 to 9 with additional ilioinguinal blockade, with no differences in requirement for sedation. There were significantly (P<0.05) more patients with intra-operative visual analogue pain scale ≥30 in the placebo group vs the ilioinguinal blockade group. Postoperative pain scores and analgesic requirements were similar.

Conclusion. Combined ilioinguinal blockade and local infiltration anaesthesia is recommended for groin hernia repair to reduce intra-operative pain.

Keywords: anaesthetic techniques, regional, inguinal ; anaesthetic techniques, subcutaneous ; surgery, hernia


    Introduction
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Elective inguinal groin hernia repair may be performed under general anaesthesia, regional anaesthesia (spinal or epidural), or local infiltration anaesthesia. Current evidence supports the use of local infiltration anaesthesia as it has a shorter intra-hospital recovery, less urinary morbidity and overall costs.1 2 However, despite these advantages local infiltration anaesthesia is rarely used,35 outside dedicated hernia centres.610 One of the explanations to the infrequent use of local infiltration anaesthesia may be intra-operative patient discomfort and pain,9 other reasons being tradition and surgeon preferences.

Although step-wise, local infiltration anaesthesia has been recommended without additional ilioinguinal blockade,8 most studies have utilized this technique together with sedation with moderate to high doses of benzodiazepines, requiring attendance of an anaesthetist. The argument for this combined technique has been improved patient satisfaction compared with unmonitored local infiltration anaesthesia with only small doses of sedation.

In order to improve intra-operative analgesia a combined ilioinguinal blockade plus step-wise local infiltration anaesthesia may be rational, but there are no data from randomized studies to support this approach in adults. Therefore, the purpose of the present study was in a double-blind, randomized set-up to investigate whether an additional ilioinguinal blockade could improve intra-operative analgesia in inguinal hernia mesh repair under un-monitored step-wise local infiltration anaesthesia.


    Patients and methods
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
160 patients undergoing elective, inguinal hernia repair under un-monitored step-wise local infiltration anaesthesia were randomized to an additional ilioinguinal blockade with 10 ml bupivacaine 0.25% or isotonic saline in a double-blind fashion.

All operations were performed by two experienced hernia surgeons (F.H.A. and K.N.). Inclusion criteria were a primary inguinal hernia repair and age over 18 yr. Patients with bilateral hernias, with preoperative chronic pain problems, linguistic difficulties, an irreducible or recurrent hernia, and body weight more than 100 kg were excluded.

The anaesthetic regimen was administered without attendance of an anaesthesiologist or nurse anaesthetist. Pre-medication was not utilized. Intra-operative sedation with intermittent doses of 1–2 mg midazolam was administered when requested by the patient. Twenty minutes before surgery an ilioinguinal block with 10 ml of bupivacaine 0.25% or isotonic saline was performed by injection 3–4 cm medially of the anterior superior iliac spine. Blinded ampules of bupivacaine or saline were provided by AstraZeneca, Södertälje, Sweden, who also made a computerized randomization. In addition, a step-wise infiltration anaesthesia was provided with bupivacaine 0.25% injected intra- and subcutaneously and subfacially and in the deeper layers during the operation.8

Immediately postoperatively the patient assessed intra-operative pain experience on a visual analogue pain scale (VAS) and again 24 and 48 h postoperatively. Consumption of analgesics (ibuprofen, acetaminophen, and tramadol) was recorded. For postoperative pain, acetaminophen l g every 6 h together with ibuprofen 600 mg every 8 h were recommended with additional tramadol 50 mg if required.

The study was in accordance with the Helsinki-II declaration and approved by the local ethical committee in Copenhagen. Patients gave written informed consent. Data are presented as mean (SD) for continuous numerical data and as median values (IR, interquartile range) for ordinal data. P<0.05 was considered significant. Statistical evaluation was done with the Mann–Whitney test and the {chi}2 test where appropriate. All data analysis and statistical tests were performed with SPSS 10.1 for windows.


    Results
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 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Of the 160 patients, one patient was excluded because of an electrical power cut after completion of local infiltration and in two patients assessment schemes were lost. Of the 157 patients completing the study, two patients did not return the questionnaires at 24 and 48 h. Patient characteristics, sedation, and anaesthesia data are shown in Table 1; there were no differences in age, use of sedation and amount of bupivacaine for infiltration anaesthesia between the two groups. Intra-operative use of midazolam for sedation was low (l.0 mg) and similar in the two groups.


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Table 1 Patient characteristics, anaesthesia and sedation data, and analgesic use from 0–24 and 24–48 h postoperatively in patients undergoing inguinal herniorrhaphy with or without additional ilioinguinal block (P>0.05 between groups). Data are mean (range) or mean (SD)

 
The median intra-operative VAS score was 9 (IR 15) in the group receiving additional ilioinguinal blockade vs 13 (IR 16) in the group receiving placebo ilioinguinal blockade (P=0.02) (Fig. 1). There was no difference in pain scores or analgesic requirements at 24 and 48 h postoperatively (Table 1 and Fig. 1). Distribution of intra-operative VAS scores showed a greater number (P<0.05) of patients having a VAS score ≥30 intra-operatively in patients receiving placebo vs bupivacaine ilioinguinal blockade (Fig. 2).



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Fig 1 Pain scores (VAS), intra-operatively and 24 and 48 h postoperatively in patients operated in local infiltration anaesthesia with or without additional ilioinguinal block (median values, *P<0.05).

 


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Fig 2 Number of patients with intra-operative pain when operated in local infiltration anaesthesia with and without additional ilioinguinal block.

 

    Discussion
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 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
The results of this randomized study show that additional preoperative ilioinguinal blockade together with step-wise local infiltration anaesthesia procedure8 improves intra-operative analgesia during unmonitored inguinal hernia mesh repair. These results may have important clinical implications as it is well established that local infiltration anaesthesia may be the most cost-effective anaesthetic technique for inguinal hernia repair.1 2 Despite the firm evidence to support the use of local anaesthesia1 data from clinical practice35 show that this technique is not widely used, probably because of the risk of intra-operative pain, surgical preferences, and traditional use of monitored anaesthesia care with additional doses of propofol and short acting opioids.9 1114

Although unmonitored local infiltration anaesthesia may provide significant cost reduction, obviously further safety studies are required to support previous large series from single centres9 and the present study.

The results of the present study are not surprising in that several previous authors have shown that an ilioinguinal blockade may provide better postoperative pain relief following inguinal hernia repair in adults1214 and children15 16 compared with placebo. However, in these studies intra-operative pain could not be assessed as the patients were treated with monitored anaesthesia care with use of higher doses of pre-medication and/or intra-operative propofol and opioid.1214

The improved intra-operative pain relief associated with an additional ilioinguinal blockade had no effect on later (24 and 48 h) pain scores or analgesic use. These findings are consistent with a systematic review of randomized studies on pre-emptive analgesia, demonstrating that early pre/intra-operative intervention may not have long lasting analgesic effects into the postoperative period compared with post-incisional administration.17

In conclusion, the additional use of a preoperative ilioinguinal field block to the well established step-wise local infiltration anaesthesia procedure8 for inguinal hernia repair improves intra-operative pain relief and is therefore recommended. This technique may support a more wide-spread use of local anaesthesia for inguinal hernia repair.


    Acknowledgments
 
Supported by a grant from Danish Research Council (22-01-0160). AstraZeneca, Södertalje, Sweden provided the blinded ampules ofmedicine.


    References
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 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
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16 Anatol TI, Pitt-Miller P, Holder Y. Trial of three methods of intraoperative bupivacaine analgesia for pain after paediatric groin surgery. Can J Anaesth 1997; 44: 1053–9[Abstract]

17 Møniche S, Kehlet H, Dahl JB. A qualitative and quantitative systematic review of preemptive analgesia for postoperative pain relief—the role of timing of analgesia. Anesthesiology 2002; 96: 725–41[ISI][Medline]