Ghimire et al.

BMC Anesthesiology (2020) 20:137

https://doi.org/10.1186/s12871-020-01054-2

RESEARCH ARTICLE Open Access

The effect of intraoperative lidocaine

infusion on opioid consumption and pain
after totally extraperitoneal laparoscopic
inguinal hernioplasty: a randomized
controlled trial
Anup Ghimire1, Asish Subedi2* , Balkrishna Bhattarai2 and Birendra Prasad Sah2

Abstract
Background: As a component of multimodal analgesia, the administration of systemic lidocaine is a well-known
technique. We aimed to evaluate the efficacy of lidocaine infusion on postoperative pain-related outcomes in
patients undergoing totally extraperitoneal (TEP) laparoscopies inguinal hernioplasty.
Methods: In this randomized controlled double-blind study, we recruited 64 patients to receive either lidocaine 2%
(intravenous bolus 1.5 mg. kg − 1 followed by an infusion of 2 mg. kg− 1. h− 1), or an equal volume of normal saline.
The infusion was initiated just before the induction of anesthesia and discontinued after tracheal extubation. The
primary outcome of the study was postoperative morphine equivalent consumption up to 24 h after surgery.
Secondary outcomes included postoperative pain scores, nausea/vomiting (PONV), sedation, quality of recovery
(scores based on QoR-40 questionnaire), patient satisfaction, and the incidence of chronic pain.
Results: The median (IQR) cumulative postoperative morphine equivalent consumption in the first 24 h was 0 (0–1)
mg in the lidocaine group and 4 [1–8] mg in the saline group (p < 0.001). Postoperative pain intensity at rest and
during movement at various time points in the first 24 h were significantly lower in the lidocaine group compared
with the saline group (p < 0.05). Fewer patients reported PONV in the lidocaine group than in the saline group (p <
0.05). Median QoR scores at 24 h after surgery were significantly better in the lidocaine group (194 (194–196) than
saline group 184 (183–186) (p < 0.001). Patients receiving lidocaine were more satisfied with postoperative analgesia
than those receiving saline (p = 0.02). No difference was detected in terms of postoperative sedation and chronic
pain after surgery.
Conclusions: Intraoperative lidocaine infusion for laparoscopic TEP inguinal hernioplasty reduces opioid
consumption, pain intensity, PONV and improves the quality of recovery and patient satisfaction.
Trial registration: ClinicalTrials.gov- NCT02601651. Date of registration: November 10, 2015.
Keywords: Inguinal hernia, Laparoscopy, Lidocaine, Opioid analgesic, Postoperative pain

* Correspondence: asishsubedi19@gmail.com; ashish.subedi@bpkihs.edu

2
Department of Anesthesiology & Critical Care Medicine, BP Koirala Institute
of Health Sciences, Dharan, Nepal
Full list of author information is available at the end of the article

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Ghimire et al. BMC Anesthesiology (2020) 20:137 Page 2 of 8

Background years, of ASA physical status I–II, planned for laparo-

Inadequate pain relief after surgery causes undesirable scopic TEP repair of the inguinal hernia were eligible.
effects. On the other hand, excessive use of opioids Patients were excluded if they were obese, unable to
produces several adverse effects and might delay comprehend the pain assessment scale, allergic to local
recovery [1, 2]. Therefore, a multimodal analgesia regi- anesthetics, on pain medication or anti-arrhythmic
men is recommended in the perioperative setting as it drugs, or had, psychiatric disorders, cardiac arrhythmia,
provides superior analgesia and reduces opioid require- hepatorenal disease or epilepsy.
ment [3]. Intravenous (IV) lidocaine is a widely studied After obtaining written informed consent, all eligible
drug for multimodal analgesia. IV lidocaine at the doses participants were randomly assigned, in a 1:1 ratio, to re-
between 1.5–3 mg. kg− 1. h− 1 produces analgesic, anti- ceive either lidocaine (intervention) or normal saline
hyperalgesic, and anti-inflammatory effects [4]. Besides, (placebo comparator) infusion. The anesthesia support-
a low dose of lidocaine is relatively safe and more feas- ing staff created the trial-group assignment from the
ible for perioperative use [4–7]. Additional benefits of computer-based randomization list, which remained se-
lidocaine infusion include a reduction in the incidence cured in sequentially numbered sealed opaque envelopes
of postoperative nausea and vomiting, early return of and concealed until after enrollment.
bowel motility and improved quality of recovery [8]. On the day of surgery, an anesthesia assistant not in-
Several studies have shown that perioperative lidocaine volved in the study prepared the drug solution after
infusion reduces postoperative pain intensity and opioid breaking the codes. Patients received one of the two
consumption, while others have found lidocaine to be assigned study medications just before the induction of
ineffective [8]. These inconsistent findings may be due anesthesia: Lidocaine group received an IV bolus of 1.5
to variation in surgical procedure, dose and duration of mg. kg− 1 lidocaine (Lox 2%®, Neon pharmaceuticals
lidocaine infused. Interestingly, a current update from limited, Mumbai, India) followed by a continuous infu-
Cochrane based meta-analysis found a weak evidence for sion of 2 mg. kg− 1. h− 1 until the tracheal extubation;
IV lidocaine compared to placebo on early postoperative The saline group received an equal volume of IV 0.9%
pain scores and overall opioid requirements [9]. On the normal saline (NS) bolus followed by a continuous infu-
contrary, other recently published meta-analyses have sion. Patients, attending anesthesiologists, and the inves-
shown improvement in postoperative pain-related tigator who collected the data and assessed the
outcomes with lidocaine infusion during laparoscopic outcomes were unaware of the trial-group assignment.
clolecystectomy [10, 11]. Patients received no premedication. During the pre-
Although lidocaine infusion was effective for postoper- anesthetic visit, they were educated on the numeric pain
ative analgesia in open inguinal hernia surgery [12], its rating scale (NRS, 0–10 cm) for postoperative pain,
use has not been reported in totally extraperitoneal where 0 is no pain and 10 is the worst imaginable excru-
(TEP) laparoscopic inguinal hernioplasty. Therefore, the ciating pain. In the operating room, standard monitoring
primary objective of our study was to compare the was applied. Just before the induction of anesthesia,
effects of intraoperative lidocaine infusion on postopera- patients received the study drug, according to the group
tive opioid consumption following TEP laparoscopic allocation. Anesthesia was induced with IV fentanyl
inguinal hernioplasty. 1.5 μg. kg− 1 and propofol 2–2.5 mg. kg− 1 till the cessa-
tion of verbal response and the tracheal intubation was
Methods facilitated with vecuronium 0.1 mg. kg− 1 IV. The lungs
This prospective randomized double-blind clinical trial were mechanically ventilated in volume control mode,
was conducted at the BP Koirala Institute of Health maintaining the end-tidal carbon dioxide (ETCO2)
Sciences (BPKIHS) from December 2015 to March 2017. between 35 and 45 mmHg.
Ethical approval for this study (Ref No. IRC/520/015) Intravenous paracetamol 1 g was administered for 15
was provided by the Institutional review committee of min after tracheal intubation. Pre-incisional infiltration
BPKIHS, Dharan, Nepal (Member secretary Dr. Ashish in the three trocar sites was done with 2 ml of 0.25%
Shrestha) on 24 June 2015. Before enrollment of pa- bupivacaine. Anesthesia was maintained with an air /
tients, the trial was registered by the principal investiga- oxygen mixture (inspired oxygen fraction 0.40) and
tor (AG) at clinicaltrials.gov (Ref No. NCT02601651). isoflurane, adjusting the end-tidal concentration of iso-
The trial was conducted according to Good Clinical flurane to maintain mean arterial pressure (MAP) within
Practice and the Consolidated Standards of Reporting 20% of the baseline. IV fentanyl 0.5 μg. kg− 1 was supple-
Trials (CONSORT) guidelines. mented intraoperatively if MAP and heart rate increased
Patients were screened for eligibility (AG) during the by 20% from the baseline after ensuring adequate end-
pre-anesthetic visit at the in-patient-unit, the night be- tidal concentration of isoflurane, neuromuscular
fore surgery. Male patients aged between 18 and 65 blockade and targeted range of ETCO2. The adequate
Ghimire et al. BMC Anesthesiology (2020) 20:137 Page 3 of 8

neuromuscular blockade was achieved with supplemen- answer the following question: Do you feel any pain in
tal doses of vecuronium IV bolus after observing curare the operated area?
notch in capnograph. Any episode of intraoperative The sample size calculation was based on the study by
hypotension (MAP < 65 mmHg) and bradycardia (heart H Kang on postoperative opioid consumption between
rate < 50 beats. min− 1) was treated with ephedrine 5 mg the lidocaine infusion group and the placebo group in
and atropine 0.4 mg IV respectively. open inguinal hernia surgery [12]. Using an online statis-
An experienced surgeon performed the TEP laparo- tical calculator (G power® version 3.0.1), an estimated
scopic surgery for inguinal hernia repair as described sample size of 29 patients in each study group achieved
elsewhere [13]. Ketorolac 30 mg IV was administered a power of 80% to detect a Cohen’s d effect size of 0.76
at the end of surgery and scheduled to be given at 8 in the primary outcome measure of opioid consumption,
h intervals. The residual neuromuscular block was re- assuming a type I error of 0.05. With an anticipated 10%
versed with IV neostigmine 0.05 mg. kg− 1 and glyco- drop-out, a total of 64 patients were enrolled.
pyrrolate 0.01 mg. kg− 1. Following successful tracheal The data were entered into excel software and ana-
extubation, the study drug was discontinued and the lyzed using STATA version 13.0 (Stata Corporation,
patient was transferred to the postanesthesia care unit College Station, TX, USA). Histograms and the Shapiro-
(PACU). Wilk test was used to check the normality of the data.
The blinded investigator assessed the postoperative Normally distributed data were compared using a 2-
outcomes. The primary outcome was total IV morphine tailed t-test for independent samples. Non-normally dis-
equivalent consumed in the first 24 h. Secondary out- tributed data were analyzed using the Mann-Whitney U
comes were postoperative pain scores (NRS) at rest and test. For ordinal data, the Kruskal-Wallis test was ap-
on movement, sedation scores recorded using a 5-point plied. Chi-square test or Fischer’s exact test was used for
scale (0 = alert, 1 = arouses to voice, 2 = arouses with analyzing the categorical variables as appropriate. The
gentle tactile stimulation, 3 = arouses with vigorous finding with an associated p-value less than 0.05 was
tactile stimulation, 4 = lack of responsiveness) [14], the considered as statistically significant.
incidence of PONV using a 3-point scale (0 = none, 1 =
nausea, 2 = vomiting), time to the first perception of Results
pain (min), time to first void (h), adverse events (light- Of the 82 screened patients, 18 patients were excluded
headedness, tinnitus, perioral numbness, arrhythmia), (Fig. 1). Two patients in each group could not be traced
quality of recovery based on QoR-40 questionnaire [15] during follow-up in 3 months. All outcomes were ana-
at 24 h after surgery, patient satisfaction for postopera- lyzed with the intention-to-treat principle. The demo-
tive pain relief using a five-point Likert scale at 24 h graphics and surgical characteristics between the two
following surgery (1-highly satisfied, 2-satisfied, 3- groups did not reveal any significant differences
neutral, 4-not satisfied, 5-strongly dissatisfied) and the (Table 1). The median (IQR) intraoperative fentanyl con-
incidence of chronic post-surgical pain (CPSP) at 3 sumption was significantly less in the lidocaine group
months. 0(0–0) μg vs. 20 (0–30) μg in the saline group (p <
Pain and sedation scores were assessed at PACU (on 0.001).
arrival, 15 min, 30 min, 1 h, 2 h) and surgical unit (4 h, 6 The cumulative median IV morphine equivalent con-
h, 8 h, 12 h, 24 h). If the NRS score for pain was > 3 at sumption at 24 h postoperatively was significantly re-
rest, morphine 1 mg IV bolus was administered in the duced in the lidocaine group than in the saline group
PACU, and repeated at 5 min interval until NRS was ≤3. (Fig. 2). The median morphine requirement in PACU
After 2 h of the stay in the PACU, the patients were was 0 (0–1) mg in the lidocaine group compared with 2
transferred to the ward. In the surgical unit, tramadol (0–4) mg in the saline group (p = 0.003). In the surgical
50 mg IV was administered for NRS score > 3 and 50 mg unit, patients consumed a lesser median (IQR) tramadol
was repeated at 10 min interval, up to a maximum dose in the lidocaine group, 0 (0–0) mg compared with the
of 300 mg in the first 24 h for maintaining VAS score for saline group 0 (0–50) mg (p < 0.001). The median NRS
pain ≤3. The amount of tramadol consumed was con- scores at rest and during movement were significantly
verted to an equivalent dose of morphine from an online lower in the lidocaine group than in the saline group at
dose equivalent calculator (www.clincalc.com/Opioids). all time points after surgery (Figs. 3 & 4). The time to
Ondansetron 4 mg IV was administered for persistent the first perception of pain was longer in those receiving
nausea (lasting > 5 min) or vomiting. CPSP was defined lidocaine (median 30 min (15–30) compared with those
as pain that developed after a surgical procedure and receiving NS (median 10 min (0–15); p < 0.001).
persisted at least 3 months after surgery [16]. For this, A significant number of patients in the saline group
the blinded investigator contacted the patients via tele- had PONV and needed antiemetic compared to the
phone at 3 months after surgery. They were asked to lidocaine group (Table 2). Postoperative sedation scores
Ghimire et al. BMC Anesthesiology (2020) 20:137 Page 4 of 8

Fig. 1 CONSORT diagram of patient recruitment

were comparable between the two groups. Postopera- pain intensity in comparison with normal saline in patients
tive quality of recovery and patient satisfaction with undergoing laparoscopic TEP inguinal hernia surgery. Pa-
postoperative pain relief was better in those receiving tients receiving lidocaine had fewer occurrences of PONV,
lidocaine (Table 2). No sign/symptoms related to lido- a better quality of recovery and were more satisfied with
caine toxicity were observed. One patient in the lido- postoperative pain relief than those receiving saline. Pa-
caine group developed intraoperative hypotension and tients complained of pain later in the lidocaine group than
bradycardia which was managed with ephedrine 5 mg the saline group. No significant difference was observed for
and atropine 0.4 mg intravenously. When assessed in 3 postoperative sedation and the incidence of chronic pain in
months after surgery, two (7%) patients in the lidocaine 3 months.
group developed CPSP compared to four (13%) in the It is well-established that lidocaine acts on voltage-
placebo group (p = 0.67). gated sodium channels when administered locally for
peripheral nerve block. However, at lower concentration
systemic lidocaine is insufficient to produce direct anal-
Discussion gesia solely by blocking the neuronal sodium channels
Our study showed that intraoperative infusion of low dose [17]. Although it is not fully understood how intraven-
lidocaine decreased postoperative opioid requirement and ous lidocaine produces analgesia, several potential

Table 1 Patient characteristics and surgical profiles of patients

Variables Lidocaine group Normal saline group P-value
(n = 32) (n = 32)
Age (years) 40 (30–52) 43 (33–52) 0.61
ASA PS (1/2) 28/4 27/5 0.71
2
BMI (kg/m ) 23.02 ± 2.85 22.01 ± 2.02 0.10
Surgical site: Unilateral/Bilateral 25/7 23/9 0.56
Mesh fixation (Yes/No) 31/1 32/0 0.50
Duration of surgery (min) 60 (48–90) 75 (60–90) 0.49
Intraoperative fentanyl supplement (μg) 0 (0–0) 20 (0–30) < 0.001
Notes: Values are median (IQR), mean (SD), number.
Abbreviations: BMI body mass index; ASA PS American society of Anesthesiologist physical status
Ghimire et al. BMC Anesthesiology (2020) 20:137 Page 5 of 8

Fig. 2 Total morphine equivalent for 24 h postoperatively in patients receiving lidocaine and saline. Data are presented as median and
interquartile range

mechanisms have been elucidated. Intravenous lido- due to blockade of NMDA receptor signaling and it
caine increases acetylcholine concentration at the is mediated indirectly by inhibition of the protein kin-
spinal level through an activation of both muscarinic ase C pathway [20]. In addition to this, systemic lido-
and nicotinic receptors, and thereby prolongs the pain caine has anti-inflammatory properties as a decline in
threshold [18]. Also, by activating central glycine (an pro-inflammatory cytokines is observed in patients
inhibitory neurotransmitter) receptor, systemic lido- receiving lidocaine infusion [21–23]. Because peri-
caine inhibits glutamate-induced excitatory response operative pain is linked to an inflammatory process,
on the wide dynamic response in the spinal neurons modulation of this phenomenon with the administra-
[19]. The anti-hyperalgesic effect of IV lidocaine is tion of systemic lidocaine could significantly reduce

Fig. 3 Postoperative numerical rating pain (NRS) scores at various time points at rest. Data are median with error bars showing interquartile
range. Significant difference between the groups was detected at all-time points (p < 0.05)
Ghimire et al. BMC Anesthesiology (2020) 20:137 Page 6 of 8

Fig. 4 Post-operative numerical rating pain scores (NRS) at various time points during movement. Data are median with error bars showing
interquartile range. Significant difference between the groups was detected at all-time points (p < 0.05)

pain. Another relevant question is to explain how the lidocaine [9]. Random-effects meta-analysis from the
intraoperative administration of IV lidocaine does same review on overall total postoperative opioid
reduces opioid and pain scores beyond its infusion consumption favored lidocaine compared to the placebo
period. This could be due to its action on various (standardized mean difference (SMD) − 4.52 (mg,
receptors and signal cascades that produces an anti- morphine equivalents (MEQ), 95%CI − 6.25 to− 2.79, p <
nociceptive, anti-hyperalgesia and anti-inflammatory 0.001; I2 = 73%; 40 studies, 2201 participants). The
effects [8]. results of our study also indicated a similar reduction in
Because of its influence in several pain pathways, sys- total postoperative opioid consumption in the first 24 h
temic lidocaine is widely investigated adjuvant in the after surgery in the lidocaine group compared to the
regimen of multimodal analgesia to reduce postoperative saline group (median difference of − 4 mg morphine
opioid consumption and pain. Although the majority of equivalents), despite using multimodal analgesia in both
studies have demonstrated the analgesic effect of lido- the groups.
caine, several other trials failed to confirm it. A recently Further, the aforementioned meta-analysis [9] demon-
updated Cochrane review in 2018 has provided a much- strated reduced pain scores at rest (“early time points”-
needed insight on the analgesic property of systemic in the PACU or 1 to 4 h postoperatively) in the lidocaine

Table 2 Postoperative outcomes

Lidocaine group Saline group p-value
(n = 32) (n = 32)
Nausea 5 (16%) 14 (44%) 0.01
Vomiting 2 (6%) 8 (25%) 0.04
Antiemetic needed 3 (9%) 11 (34%) 0.01
Time to first void; h 3 (2–4) 3 (3–4) 0.18
Quality of recovery;QoR-40 scores 194 (194–196) 184 (183–186) < 0.001
a
Patients with satisfaction scores 1/2/3/4/5 6/17/9/0/0 2/13/17/0/0 0.02
Notes: Values are number (proportion), or median (IQR)
a
Satisfaction scores for postoperative pain relief, 1-Highly satisfied, 2-Satisfied, 3-Neutral, 4-Not satisfied, 5-Strongly dissatisfied
Ghimire et al. BMC Anesthesiology (2020) 20:137 Page 7 of 8

group compared to the control group (SMD − 0.50, 95% PONV, it may not reflect a causal relationship. The most
CI − 0.72 to− 0.28; Test for overall effect: Z = 4.41 (P < likely explanation for this association is related to lido-
0.0001). This was equivalent to an average pain reduc- caine’s opioid-sparing effects.
tion between 0.37 cm and 2.48 cm on a VAS 0 to 10 cm Recently, there is a growing interest in patient-
scale in the lidocaine group. Likewise, at intermediate reported outcomes such as postoperative QoR and pa-
time points (24 h postoperatively) the standardized mean tient satisfaction. We observed better recovery profiles at
pain score at rest in the lidocaine group was 0.14 lower 24 h of surgery in the lidocaine group as evident from
(95% CI − 0.25 to − 0.04; Test for overall effect: Z = 2.63 the QoR scores. Similar to our study, De Oliveira and
(P = 0.0086). This was equivalent to an average pain re- his colleagues reported greater QoR-40 scores at 24 h
duction in the lidocaine group between 0.48 cm and with perioperative lidocaine infusion for laparoscopic ab-
0.10 cm on a VAS 0 to 10 cm scale. These results dominal surgery [24, 25]. Likewise, in our study patient
showed that lidocaine exerted a clinical difference of at satisfaction was better in lidocaine than saline group and
least 1 cm on a 0–10 VAS scores for pain at rest during no patient expressed dissatisfaction over the interven-
early time points (1 to 4 h); however, this difference was tion. The current meta-analysis also supports this find-
not observed at intermediate (24 h) time points. We too ing by revealing higher satisfaction scores in patients
observed statistically significant difference in pain scores receiving lidocaine compared to placebo group (SMD
up to 24 h postoperatively, while the clinical difference 0.76, 95% CI 0.46 to 1.06; I2 = 0%; 6 studies, 306 partici-
of approximately 1 cm in NRS scores at rest was pants) [9]. Further, perioperative lidocaine infusion re-
observed only up to 1 h. duces the length of hospital stay as compared to the
Due to substantial heterogeneity between studies, the placebo. We considered this outcome as a limitation in
authors of the same meta-analysis performed a sub-group our study because all our participants were required to
analysis based on type of surgery, duration and dose of stay in the hospital for 24 h after surgery. In terms of
lidocaine infusions [9]. In the older version (Cochrane re- patient-reported outcomes, it would be interesting to ex-
view, 2015) there was a clear beneficial effect in terms of plore the influence of perioperative lidocaine on the en-
pain reduction in laparoscopic abdominal surgery com- hancement of recovery profiles, especially after major
pared to open abdominal surgery [6]. However, in the abdominal surgeries in future trials. A more recent
current updated version, no significant difference was ob- meta-analysis focused on CPSP (total 6 trials included: 4
served, although the trend was towards a beneficial effect mastectomies, 1 thyroidectomy, 1 nephrectomy) found
for abdominal laparoscopic surgery [9]. that systemic lidocaine administration reduces the devel-
The optimal dose and time to terminate lidocaine in- opment of CPSP [26]. As our study was not powered
fusion are still an unsolved issue. We had limited the enough to detect the protective effect of lidocaine on
duration of lidocaine infusion until the patients trachea CPSP after laparoscopic TEP, we would not like to draw
was extubated due to a lack of dedicated infusion pumps any conclusion. This could be explored in a larger,
and monitoring at the surgical unit. One might multi-centric trial with CPSP as a primary outcome.
hypothesize that longer infusions would lead to more
lasting analgesia but studies are yet to confirm this. The Conclusions
current meta-analysis (2018) had categorized the studies In summary, intraoperative lidocaine infusion decreases
according to the usage of low (< 2 mg.kg− 1. h− 1) and overall opioid requirement and postoperative pain inten-
high (≥ 2 mg.kg− 1 h− 1) lidocaine doses in combination sity in patients undergoing laparoscopic TEP inguinal
with either short (until the end of surgery or until hernioplasty. It also lowers the incidence of PONV, im-
PACU) or long (≥ 24 h postoperatively) duration of infu- proves the quality of recovery and patients satisfaction
sion [9]. However, they did not find any difference in without any sedative effect.
outcomes when the dose or duration of the infusion was
Abbreviations
compared. A well designed randomized comparative TEP: Totally extraperitoneal; PONV: Postoperative nausea and vomiting;
study with a large sample size is needed to explore QoR: Quality of recovery; IQR: Interquartile range; IV: Intravenous; BPKIHS: BP
whether the continuation of systemic lidocaine infusion Koirala Institute of Health Sciences; ASA: American Society of
Anesthesiologists; NS: Normal Saline; NRS: Numerical rating scale; ETC02: End-
beyond the surgical period is effective. tidal carbondioxide concentration; MAP: Mean arterial pressure; PACU: Post
In our study, fewer patients receiving lidocaine com- anesthesia care unit; CPSP: Chronic post-surgical pain; SMD: Standardized
plained PONV compared to those receiving saline infu- mean difference; MEQ: Morphine equivalent; VAS: Visual analogue scale
sions. Similar to our finding, the Cochrane meta-analysis Acknowledgements
(2018) reported a significantly lower frequency of nausea Not applicable.
in the lidocaine group than in the control group, but the
Authors’ contributions
vomiting rates did not differ [9]. Although, there is an AG: This author helped in study design, patient recruitment, data collection
association between lidocaine therapy and reduction in and writing up of the first draft of the paper. AS: This author helped in study
Ghimire et al. BMC Anesthesiology (2020) 20:137 Page 8 of 8

design, patient recruitment, data collection, analysis and interpretation of 12. Kang H, Kim BG. Intravenous lidocaine for effective pain relief after inguinal
data, manuscript revision and final draft. BB: This author helped in study herniorrhaphy: a prospective, randomized, double-blind, placebo-controlled
design, manuscript revision and final approval. BPS: This author helped in study. J Int Med Res. 2011;39:435–45.
study design, manuscript first draft and final draft. All authors have read and 13. Liem MSL, van Steensel CJ, Boelhouwer RU, et al. The learning curve for
approved the manuscript in its current state. totally extraperitoneal laparoscopic inguinal hernia repair. Am J Surg. 1996;
171:281–5.
14. De Witte JL, Alegret C, Sessler DI, Cammu G. Preoperative alprazolam
Funding
reduces anxiety in ambulatory surgery patients: a comparison with oral
None.
midazolam. Anesth Analg. 2002;95:1601–6.
15. Myles PS, Weitkamp B, Jones K, Melick J, Hensen S. Validity and reliability of
Availability of data and materials a postoperative quality of recovery score: the QoR-40. Br J Anaesth. 2000;84:
The datasets used and/or analysed during the current study are available 11–5.
from the corresponding author on reasonable request. 16. Treede RD, Rief W, Barke A, Aziz Q, Bennett MI, Benoliel R, Cohen M, Evers S,
Finnerup NB, First MB, Giamberardino MA, Kaasa S, Kosek E, Lavandʼhomme
Ethics approval and consent to participate P, Nicholas M, Perrot S, Scholz J, Schug S, Smith BH, Svensson P, Vlaeyen
The study was approved by the Institutional Review Committee (IRC), BP JW, Wang SJ. A classification of chronic pain for ICD-11. Pain. 2015;156:
Koirala Institute of Health Sciences; reference number: IRC/520/015. Written 1003–7.
informed consent was obtained from patients. 17. Brinkrolf P, Hahnenkamp K. Systemic lidocaine in surgical procedures: effects
beyond sodium channel blockade. Curr Opin Anaesthesiol. 2014;27:420–5.
18. Abelson KS, Höglund AU. Intravenously administered lidocaine in
Consent for publication therapeutic doses increases the intraspinal release of acetylcholine in rats.
Not applicable. Neurosci Lett. 2002;317:93–6.
19. Biella G, Sotgiu ML. Central effects of systemic lidocaine mediated by
Competing interests glycine spinal receptors: an iontophoretic study in the rat spinal cord. Brain
The authors declare that they have no competing interests. Res. 1993;603:201–6.
20. Hahnenkamp K, Durieux ME, Hahnenkamp A, Schauerte SK, Hoenemann
Author details CW, Vegh V, Theilmeier G, Hollmann MW. Local anaesthetics inhibit
1
Department of Anesthesiology, Nepal Mediciti Hospital, Lalitpur, Nepal. signalling of human NMDA receptors recombinantly expressed in Xenopus
2
Department of Anesthesiology & Critical Care Medicine, BP Koirala Institute laevis oocytes: role of protein kinase C. Br J Anaesth. 2006;96:77–87.
of Health Sciences, Dharan, Nepal. 21. Yardeni IZ, Beilin B, Mayburd E, Levinson Y, Bessler H. The effect of
perioperative intravenous lidocaine on postoperative pain and immune
Received: 30 January 2020 Accepted: 25 May 2020 function. Anesth Analg. 2009;109:1464–9.
22. Kuo CP, Jao SW, Chen KM, Wong CS, Yeh CC, Sheen MJ, Wu CT.
Comparison of the effects of thoracic epidural analgesia and i.v. infusion
with lidocaine on cytokine response, postoperative pain and bowel
References function in patients undergoing colonic surgery. Br J Anaesth. 2006;97:640–
1. Gan TJ, Joshi GP, Zhao SZ, Hanna DB, Cheung RY, Chen C. Presurgical 6.
intravenous parecoxib sodium and follow-up oral valdecoxib for pain 23. Herroeder S, Pecher S, Schönherr ME, Kaulitz G, Hahnenkamp K, Friess H,
management after laparoscopic cholecystectomy surgery reduces opioid Böttiger BW, Bauer H, Dijkgraaf MG, Durieux ME, Hollmann MW. Systemic
requirements and opioid-related adverse effects. Acta Anaesthesiol Scand. lidocaine shortens length of hospital stay after colorectal surgery: a double-
2004;48:1194–207. blinded, randomized, placebo-controlled trial. Ann Surg. 2007;246:192–200.
2. Magheli A, Knoll N, Lein M, Hinz S, Kempkensteffen C, Gralla O. Impact of 24. De Oliveira GS Jr, Fitzgerald P, Streicher LF, Marcus RJ, McCarthy RJ.
fast-track postoperative care on intestinal function, pain, and length of Systemic lidocaine to improve postoperative quality of recovery after
hospital stay after laparoscopic radical prostatectomy. J Endourol. 2011;25: ambulatory laparoscopic surgery. Anesth Analg. 2012;115:262–7.
1143–7. 25. De Oliveira GS Jr, Duncan K, Fitzgerald P, Nader A, Gould RW, McCarthy RJ.
3. Lau CS, Chamberlain RS. Enhanced recovery after surgery programs Systemic lidocaine to improve quality of recovery after laparoscopic
improve patient outcomes and recovery: a meta-analysis. World J Surg. bariatric surgery: a randomized double-blinded placebo-controlled trial.
2017;41:899–913. Obes Surg. 2014;24:212–8.
4. Marret E, Rolin M, Beaussier M, Bonnet F. Meta-analysis of intravenous 26. Bailey M, Corcoran T, Schug S, Toner A. Perioperative lidocaine infusions for
lidocaine and postoperative recovery after abdominal surgery. Br J Surg. the prevention of chronic postsurgical pain: a systematic review and meta-
2008;95:1331–8. analysis of efficacy and safety. Pain. 2018;159:1696–704.
5. Sun Y, Li T, Wang N, Yun Y, Gan TJ. Perioperative systemic lidocaine for
postoperative analgesia and recovery after abdominal surgery: a meta-
analysis of randomized controlled trials. Dis Colon Rectum. 2012;55:1183–94. Publisher’s Note
6. Kranke P, Jokinen J, Pace NL, et al. Continuous intravenous perioperative Springer Nature remains neutral with regard to jurisdictional claims in
lidocaine infusion for postoperative pain and recovery. Cochrane Database published maps and institutional affiliations.
Syst Rev. 2015;7:CD009642.
7. Bajracharya JL, Subedi A, Pokharel K, Bhattarai B. The effect of intraoperative
lidocaine versus esmolol infusion on postoperative analgesia in laparoscopic
cholecystectomy: a randomized clinical trial. BMC Anesthesiol. 2019;19:198.
8. Dunn LK, Durieux ME. Perioperative use of intravenous lidocaine.
Anesthesiology. 2017;126:729–37.
9. Weibel S, Jelting Y, Pace NL, et al. Continuous intravenous perioperative
lidocaine infusion for postoperative pain and recovery in adults. Cochrane
Database Syst Rev. 2018;6:CD009642.
10. Zhao JB, Li YL, Wang YM, Teng JL, Xia DY, Zhao JS, Li FL. Intravenous
lidocaine infusion for pain control after laparoscopic cholecystectomy: a
meta-analysis of randomized controlled trials. Medicine (Baltimore).
2018;97:e9771.
11. Li J, Wang G, Xu W, Ding M, Yu W. Efficacy of intravenous lidocaine on pain
relief in patients undergoing laparoscopic cholecystectomy: a meta-analysis
from randomized controlled trials. Int J Surg. 2018;50:137–45.