The most common problems immediately following surgery are pain, nausea and vomiting, excessive blood clotting, slowing or stopping of the movement of food and fluid through the digestive system, and postoperative cognitive dysfunction. Fast-track protocols aim to prevent or reduce these complications and speed up early recovery. Opioid medications that are given to reduce the postoperative pain can be associated with side effects including nausea and constipation, which prevent a smooth recovery. Other options include the administration of epidural opioid medications (injected into the space surrounding the spinal cord). The pain can be a mixture of inflammatory and neuropathic pain or based on increased sensitivity to pain. All are helped by intravenous lidocaine, which is a non-opioid local pain medication or local anaesthetic.
The aim of this review of the medical literature was to assess the benefits and risks of intravenous lidocaine infusion started at the time of surgery on pain and recovery after surgery in patients undergoing various surgical procedures. We found 45 randomized controlled clinical studies comparing the use of intravenous lidocaine during and after the surgery with placebo or standard care or with epidural analgesia (two studies only). We presented data from a total of 2802 participants. The overall methodological quality (risk of bias) of the included studies was moderate to high.
The results from over 1200 participants showed that pain immediately after surgery (23 studies) and until 24 hours (25 studies) was reduced by lidocaine infusion when compared to placebo or usual care. Pain reduction was most obvious at up to four hours in participants undergoing laparoscopic abdominal surgery or open abdominal surgery. Pain at 48 hours was not reduced (19 studies). We found further positive effects of lidocaine infusion on recovery of bowel function, with a reduction in the time to first flatus (11 studies) and first bowel movements or sounds (6 studies), and reduced risk of paralytic ileus (3 studies) but not the time to first defaecation (4 studies). Participants receiving lidocaine experienced less nausea (28 studies), possibly because they required fewer opioids for pain relief (32 studies). The length of hospital stay was slightly shortened (21 studies).
Few trials looked at other surgical complications such as postoperative infection, urinary retention, bleeding, deep vein thrombosis, and wound healing disturbances and there was no evidence of either benefit or harm.
Seventeen studies systematically analysed the occurrence of adverse effects. There was no evidence that intravenous lidocaine was associated with an increased risk of adverse effects such as death, arrhythmias, other heart rate disorders, or signs of lidocaine toxicity. The occurrence of side effects associated with lidocaine infusion could not be reliably assessed since the clinical studies did not satisfactorily address this question.
Major limitations of this review were, firstly, the large and unexplained statistical heterogeneity between the studies, which was not adequately explained by type of surgical procedure; and secondly, that evidence comes only from small studies, which bear the risk of overestimated treatment effects. Both limitations reduced the quality of the evidence for most of the outcomes. Only the outcomes 'early pain following open abdominal surgery' and 'early postoperative nausea' reached a moderate quality level of evidence.
There is low to moderate evidence that this intervention, when compared to placebo, has an impact on pain scores, especially in the early postoperative phase, and on postoperative nausea. There is limited evidence that this has further impact on other relevant clinical outcomes, such as gastrointestinal recovery, length of hospital stay, and opioid requirements. So far there is a scarcity of studies that have systematically assessed the incidence of adverse effects; the optimal dose; timing (including the duration of the administration); and the effects when compared with epidural anaesthesia.
The management of postoperative pain and recovery is still unsatisfactory in clinical practice. Opioids used for postoperative analgesia are frequently associated with adverse effects including nausea and constipation. These adverse effects prevent smooth postoperative recovery. On the other hand not all patients may be suited to, and take benefit from, epidural analgesia used to enhance postoperative recovery. The non-opioid lidocaine was investigated in several studies for its use in multi-modal management strategies to reduce postoperative pain and enhance recovery.
The aim of this review was to assess the effects (benefits and risks) of perioperative intravenous lidocaine infusion compared to placebo/no treatment or compared to epidural analgesia on postoperative pain and recovery in adults undergoing various surgical procedures.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 5 2014), MEDLINE (January 1966 to May 2014), EMBASE (1980 to May 2014), CINAHL (1982 to May 2014), and reference lists of articles. We searched the trial registry database ClinicalTrials.gov, contacted researchers in the field, and handsearched journals and congress proceedings. We did not apply any language restrictions.
We included randomized controlled trials comparing the effect of continuous perioperative intravenous lidocaine infusion either with placebo, or no treatment, or with epidural analgesia in adults undergoing elective or urgent surgery under general anaesthesia. The intravenous lidocaine infusion must have been started intraoperatively prior to incision and continued at least until the end of surgery.
Trial quality was independently assessed by two authors according to the methodological procedures specified by the Cochrane Collaboration. Data were extracted by two independent authors. We collected trial data on postoperative pain, recovery of gastrointestinal function, length of hospital stay, postoperative nausea and vomiting (PONV), opioid consumption, patient satisfaction, surgical complication rates, and adverse effects of the intervention.
We included 45 trials involving 2802 participants. Two trials compared intravenous lidocaine versus epidural analgesia. In all the remaining trials placebo or no treatment was used as a comparator. Trials involved participants undergoing open abdominal (12), laparoscopic abdominal (13), or various other surgical procedures (20).
The risk of bias was low with respect to selection bias (random sequence generation), performance bias, attrition bias, and detection bias in more than 50% of the included studies. For allocation concealment and selective reporting the quality assessment yielded low risk of bias for only approximately 20% of the included studies.
We found evidence of effect for intravenous lidocaine on the reduction of postoperative pain (visual analogue scale, 0 to 10 cm) compared to placebo or no treatment at 'early time points (one to four hours)' (mean difference (MD) −0.84 cm, 95% confidence interval (CI) −1.10 to −0.59; low-quality evidence) and at 'intermediate time points (24 hours)' (MD −0.34 cm, 95% CI −0.57 to −0.11; low-quality evidence) after surgery. However, no evidence of effect was found for lidocaine to reduce pain at 'late time points (48 hours)' (MD -0.22 cm, 95% CI −0.47 to 0.03; low-quality evidence). Pain reduction was most obvious at 'early time points' in participants undergoing laparoscopic abdominal surgery (MD −1.14, 95% CI −1.51 to −0.78; low-quality evidence) and open abdominal surgery (MD −0.72, 95% CI −0.96 to −0.47; moderate-quality evidence). No evidence of effect was found for lidocaine to reduce pain in participants undergoing all other surgeries (MD −0.30, 95% CI −0.89 to 0.28; low-quality evidence). Quality of evidence is limited due to inconsistency and indirectness (small trial sizes).
Evidence of effect was found for lidocaine on gastrointestinal recovery regarding the reduction of the time to first flatus (MD −5.49 hours, 95% CI −7.97 to −3.00; low-quality evidence), time to first bowel movement (MD −6.12 hours, 95% CI −7.36 to −4.89; low-quality evidence), and the risk of paralytic ileus (risk ratio (RR) 0.38, 95% CI 0.15 to 0.99; low-quality evidence). However, no evidence of effect was found for lidocaine on shortening the time to first defaecation (MD −9.52 hours, 95% CI −23.24 to 4.19; very low-quality evidence).
Furthermore, we found evidence of positive effects for lidocaine administration on secondary outcomes such as reduction of length of hospital stay, postoperative nausea, intraoperative and postoperative opioid requirements. There was limited data on the effect of IV lidocaine on adverse effects (e.g. death, arrhythmias, other heart rate disorders or signs of lidocaine toxicity) compared to placebo treatment as only a limited number of studies systematically analysed the occurrence of adverse effects of the lidocaine intervention.
The comparison of intravenous lidocaine versus epidural analgesia revealed no evidence of effect for lidocaine on relevant outcomes. However, the results have to be considered with caution due to imprecision of the effect estimates.