Page 80 - International guidelines for groin hernia management

Hernia

were all reported in the same four publications. There were One systematic review on preemptive analgesia con-
no significant differences in testicular problems between cluded that it can reduce acute postoperative pain. It also
groups. One of the meta-analyses reported testicular atro- commented on the need for additional studies on gaba-
phy in 0.8% of patients and chronic pain in 11.2%. 60 pentin and pregabalin before recommending their use in
Irrespective of surgical technique, the incidence of chronic pain prophylaxis. 214 However, the review sum-
orchialgia is about the same, roughly 10% of the incidence marized, the cause of chronic pain being multifactorial, that
of CPIP. a combination of intraoperative and postoperative pain
New directions in acute/chronic pain prevention. therapy is needed to minimize the risk of developing
chronic pain. 214
Introduction Another systematic review found no evidence to support
Preoperative and intraoperative methods (various medica- preemptive analgesia use in chronic postsurgical pain
tions, psychological treatments and preparation, and edu- prevention. 215
cational programs) have been used in attempts to prevent A Cochrane review on high-dose topical capsaicin on
chronic pain. Many of the techniques hinge on surveying intact skin for chronic neuropathic pain from postherpetic
psychological risk factors for chronic pain after hernia neuralgia and HIV neuropathy found a significant benefit
operations. A few psychologically based studies examining during a 12-week study period. 216 One study of wound
counseling or education have been published that related to instillation of capsaicin showed superior analgesia versus
hernia surgery. placebo in the 3–4 days following IH repair. 217 Follow-up
at 2.5 years revealed that 5 of 20 patients in the capsaicin
Key question group had hyperalgesia compared to 1 of 16 in the placebo
group. This trend did not rise to the level of statistical
KQ19P.m Can preoperative and perioperative topical and significance. 218
systemic medications reduce the incidence of chronic pain? Etanercept—a tumor necrosis factor-alpha inhibitor—
KQ19P.n Can chronic postoperative pain be prevented or has the potential to inhibit neuropathic pain. When this
reduced by preoperative information and psychological agent was used to treat postamputation pain, 5 of 6 soldiers
preparation? in whom it was employed reported improvement. 219 In a

Perioperative prevention of chronic pain subsequent multicenter randomized study, etanercept was
given 90 min before IH surgery and reduced postoperative
Evidence in literature pain by some measures. However, the effect was small,
A review on persistent postsurgical pain concluded that transient, and not statistically significant. 220
nerve injury is the major factor causing chronic pain. It Preoperative education and psychological preparation
further surmised that preempting neuropathic pain requires
a different approach from that needed for preventing Evidence in literature
inflammatory pain. 211 Preemptive analgesia attempts to
reduce sensory input from the surgical trauma causing In a systematic review of experimental pain studies
sensitization and an increased risk of chronic postoperative investigating quantitative sensory testing, the variance in
pain. Analgesia timing is considered to be crucial. 212 postoperative pain could be predicted in 4–54% of patients.
A systematic review and meta-analysis including 11 Preoperative psychometric evaluations of vulnerability,
clinical trials on perioperative administration of gabapentin anxiety, depression, and pain catastrophizing were less
or pregabalin found that they were effective in reducing the predictive. 156 Numerous studies from a variety of disci-
incidence of chronic postsurgical pain. 213 Of eight gaba- plines have identified psychological risk factors for chronic
pentin trials, four (one of which was a hernia repair pain. 155, 214, 221–224
study 211 ) reported lower incidence of pain and/or lower Few studies exist on preoperative preparation and edu-
analgesic requirement [ 2 months after surgery. So did all cation of patients to reduce chronic postoperative pain. A
three pregabalin trials. prospective randomized study did evaluate the influence of

123