Efficacy of intraoperative systemic lidocaine on quality of recovery after laparoscopic colorectal surgery: a randomized controlled trial

Abstract

Introduction

Many clinical trials have demonstrated the benefits of intraoperative systemic lidocaine administration in major abdominal surgeries. We tested the hypothesis that systemic lidocaine is associated with an enhanced early quality of recovery in patients following laparoscopic colorectal resection.

Patients and Methods

We randomly allocated 126 patients scheduled for laparoscopic colorectal surgery in a 1:1 ratio to receive either lidocaine (1.5 mg kg⁻¹ bolus over 10 min, followed by continuous infusion at 2 mg kg⁻¹ h⁻¹ until the end of surgery) or identical volumes and rates of saline. The primary outcome was the Quality of Recovery-15 score assessed 24 h after surgery. Secondary outcomes were areas under the pain numeric rating scale curve over time, 48-h morphine consumption, and adverse events.

Results

Compared with saline, systemic lidocaine improved the Quality of Recovery-15 score 24 h postoperatively, with a median difference of 4 (95% confidence interval: 1–6; p = 0.015). Similarly, the area under the pain numeric rating scale curve over 48 h at rest and on movement was reduced in the lidocaine group (p = 0.004 and p < 0.001, respectively). However, these differences were not clinically meaningful. Lidocaine infusion reduced the intraoperative remifentanil requirements but not postoperative 48-h morphine consumption (p < 0.001 and p = 0.34, respectively). Additionally, patients receiving lidocaine had a quicker and earlier return of bowel function, as indicated by a shorter time to first flatus (log-rank p < 0.001), yet ambulation time was similar between groups (log-rank test, p = 0.11).

Conclusions

In patients undergoing laparoscopic colorectal surgery, intraoperative systemic lidocaine resulted in statistically but not clinically significant improvements in quality of recovery (see Graphical Abstract).

Trial registration: Chinese Clinical Trial Registry; ChiCTR1900027635.

KEY MESSAGES

• Systemic lidocaine failed to clinically improve the overall quality of recovery following laparoscopic colorectal resection.

• Systemic lidocaine reduced intraoperative remifentanil and time to first flatus but not postoperative 48-h morphine consumption.

• No differences emerged in patient-reported outcomes like opioid side effects, mobility, or satisfaction between groups postoperatively.

Graphical Abstract

Keywords:

• Colorectal surgery
• lidocaine
• pain management
• post-surgical recovery

Introduction

Laparoscopic colorectal resection, a minimally invasive surgical technique, offers several advantages over open surgery [1,2]. However, despite these benefits, up to 46% of patients still complain of moderate to severe postoperative pain following laparoscopic colorectal resection, potentially leading to unfavourable physiological responses and impeding overall clinical recovery [3,4]. Traditionally, opioids have been the primary approach for managing postoperative pain. Nevertheless, their excessive use may expose patients to various adverse effects, such as nausea, vomiting, constipation, sedation, respiratory depression, as well as risks of tolerance and dependency [5]. Consequently, healthcare providers have shifted their focus from opioid-based to opioid-sparing multimodal analgesia strategies [6], in line with the recommendations of the Enhanced Recovery after Surgery (ERAS) guidelines [7,8].

One such opioid-sparing strategy is intraoperative systemic lidocaine, an amino-amide local anaesthetic agent administered intravenously and known for its antinociceptive, antihyperalgesic, and anti-inflammatory properties. A growing number of clinical trials, primarily in abdominal surgeries, have substantiated the efficacy of intravenous lidocaine in improving postoperative analgesia, reducing opioid consumption, and facilitating gastrointestinal recovery [9–11]. However, the heterogeneous results and potential biases arising from methodological inconsistencies across these studies necessitate a more critical and comprehensive analysis [12,13]. While lidocaine’s immediate analgesic effects have been well documented quantitatively, its broader impacts on patient outcomes, such as comfort, mobility, psychological well-being, and postsurgical satisfaction, remain unclear. This highlights a critical need for an in-depth examination of the implications of systemic lidocaine administration perioperatively, advocating a shift towards a holistic, patient-centred perspective in evaluating postoperative recovery [14].

To address this knowledge gap, we conducted a randomized clinical trial to examine the hypothesis that the incorporation of intraoperative systemic lidocaine into standard anaesthetic care could enhance the overall postoperative recovery for patients undergoing laparoscopic colorectal resection.

Patients and methods

Study design and participants

The Research Ethics Committee approved this prospective, randomized, two-arm parallel-group, double-blind, placebo-controlled clinical trial (identified number K2019-10-003) on October 10, 2019. Before patient enrolment, we registered the study at the Chinese Clinical Trial Registry (identified number ChiCTR1900027635, November 22, 2019). Written informed consent was obtained from adults aged 18–80 years, classified as American Society of Anesthesiologists (ASA) physical status I or II, who were scheduled for elective laparoscopic resection of colorectal cancer. Patients with contraindications to interventions, including a medical history of seizure disorders, allergies, contraindications to study medications, cardiac rhythm disorders (such as sick sinus syndrome, Adams-Stokes syndrome, second- and third-degree atrioventricular block, double-bundle branch block, or heart rate < 50 beats min⁻¹), hepatic dysfunction (total bilirubin ≥ 2 mg dL⁻¹), renal impairment (glomerular filtration rate ≤ 60 mL min⁻¹ 1.73 m⁻²), weight less than 45 kg, body mass index greater than 30 kg m⁻², inability to complete questionnaires due to language barrier or cognitive impairment, recent use of any analgesic medication within 48 h before surgery, history of alcohol or substance abuse, or presence of chronic pain syndrome, were excluded from the study. We conducted the study following the principles in the Declaration of Helsinki and the Good Clinical Practice guidelines between January 16, 2020, and March 24, 2021. No changes to the study protocol occurred after trial commencement. We prepared the manuscript in line with the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement [15].

Randomization and blinding

We randomly assigned participants in a 1:1 ratio to receive either lidocaine or 0.9% saline (Control) at the same volume and infusion rate using permuted block randomization (block size of six). The randomization list was generated using the R package ‘blockrand’ (R version 4.3.1, the R Foundation for Statistical Computing Platform). The randomization codes were concealed by a separate research assistant who was not involved in the study using consecutively numbered opaque envelopes. The lidocaine group received an initial intravenous bolus dose of 1.5 mg kg⁻¹ lidocaine over 10 min, followed by a continuous 2 mg kg⁻¹ h⁻¹ infusion until the end of surgery. The saline group received matching volumes of 0.9% saline at the same infusion rates. The study medications for the initial dose injection and intraoperative intravenous infusion were prepared by a clinical pharmacist based on a computer-generated random sequence. The former was administered using a 20 mL syringe, while the latter used a 50 mL syringe. As a result, the participant, care provider, investigator, and outcome assessor were blinded to the treatment allocation.

Anaesthetic procedure

No premedication was administered, and we recorded electrocardiogram, pulse oximetry, invasive blood pressure, capnography, temperature, and bispectral index (BIS) during the surgery. We induced anaesthesia with intravenous sufentanil 0.5 μg kg⁻¹, propofol 1–2 mg kg⁻¹, and rocuronium 0.6 mg kg⁻¹. Following endotracheal intubation, ventilation parameters, encompassing respiratory frequency and tidal volume, were adjusted to sustain the end-tidal carbon dioxide partial pressure within the range of 35 to 45 mmHg. We maintained general anaesthesia with inhaled sevoflurane (age-adjusted 0.8 minimum alveolar concentration) and continuous intravenous remifentanil administration. The BIS index was maintained at 40–60, and hemodynamic parameters (blood pressure and heart rate) fluctuated within 20% of baseline values. Muscle relaxation was achieved by the continuous infusion of cisatracurium at a rate of 1–2 µg kg⁻¹min⁻¹, as determined by the attending anaesthesiologists. The administration of intraoperative fluid therapy was guided by goal-directed therapy to maintain euvolemia [16]. In cases where hypotension occurred in the absence of hypovolemia, an intravenous ephedrine infusion was administered. Dual antiemetic agents were administered, namely, dexamethasone 8 mg before anaesthesia induction and tropisetron 5 mg before closure. Intravenous sufentanil 0.15 µg kg⁻¹ was administered 30 min before the end of the surgery. Following the closure of the surgical incision, neostigmine 20 µg kg⁻¹ and atropine 10 µg kg⁻¹ were used to reverse neuromuscular blockade as needed. Patients were extubated in the operating room and monitored in the postoperative anaesthesia care unit (PACU) for at least 60 min.

For postoperative pain, all patients were administered intravenous flurbiprofen axetil 50 mg, a nonselective cyclooxygenase inhibitor, 30 min before the skin incision, regardless of their group allocation. This was followed by every 6 h for three days after surgery. Furthermore, the patient was given patient-controlled intravenous analgesia (PCIA) using morphine, where the system was set to administer no continuous infusion and a bolus of 2 mg morphine with a lockout period of 10 min (maximum 8 mg h⁻¹) for rescue pain relief. Patients with a numeric rating scale (NRS) pain score above 3 (range 0–10, 0 indicates no pain; 10 worst pain) are instructed to administer PCIA morphine bolus. For postoperative nausea or vomiting (PONV) treatment, patients were given either 0.625 mg of droperidol intravenously in the PACU or 5 mg of tropisetron intravenously in the ward as needed.

Outcome assessment

The main objective of this study was to assess the effectiveness of intraoperative systemic lidocaine on the global QoR-15 score 24 h after laparoscopic colorectal surgery. The QoR-15 questionnaire contains 15 items measuring five domains: emotional state, psychological support, physical independence, physical comfort, and pain dimensions. Each item is scored from 0 to 10, and the global QoR-15 score varies between 0 and 150 (indicating ideal health status) [17]. A blinded independent investigator invited patients to complete the QoR-15 questionnaire preoperatively and again 24 and 48 h after the surgery. Secondary outcomes included the area under the curve (AUC) of pain NRS scores over 48 h, total morphine consumption, and adverse effects within 48 h postoperatively. The individuals used NRS to assess pain intensity at 0.5, 1, 2, 4, 8, 12, 24, and 48 h postoperatively. The AUC of pain NRS scores during 48 h were calculated by using trapezoidal integration via GraphPad Prism for Windows (version 8.0; GraphPad Software, San Diego, California, USA). Adverse effects, including PONV, dizziness, pruritus, and other opioid-related side effects, were documented in the electronic medical records. Additional exploratory outcomes were intraoperative remifentanil consumption, emergence time, time to flatus, time to ambulation, patient satisfaction score, and other adverse events. Emergence time was defined as the period from the completion of the procedure to the patient’s response to verbal commands by opening their eyes. Patients self-reported their satisfaction with postoperative pain relief 48 h after the surgery using an 11-point NRS, where zero indicated no satisfaction and ten indicated satisfaction.

Statistical analysis

According to the pilot study, the global QoR-15 score at 24 h postoperatively in the saline group was 118 (12.1). We estimated that 50 participants per arm could detect a minimum clinically important difference (MCID) of 8 points [18] between the two groups with 90% power at a significance threshold of 0.05 (PASS software 2017; NCSS LLC, Kaysville, UT, USA). We enrolled 126 individuals in this study to account for potential follow-up loss.

We assessed the normality of the continuous data distribution using the Shapiro–Wilk test. Normally distributed variables, including age, height, weight, operation duration, and anaesthesia duration, are presented as the mean and standard deviation (SD) and were analysed using two-sample independent t-tests. Nonnormally distributed variables, including QoR-15 scores, emergence time, intraoperative remifentanil consumption, postoperative morphine consumption, and AUC for NRS pain scores over 48 h, are reported as the median and interquartile range (IQR) and were analysed using Mann–Whitney U-tests. Categorical variables, such as adverse event incidence, are presented as numbers (proportions, %) and were analysed using chi-square or Fisher’s tests as appropriate. Time-to-event data for the first flatus and first ambulation were analysed using Kaplan–Meier curves and log-rank tests. A two-tailed p value < 0.05 was considered statistically significant. All statistical analyses were performed using IBM SPSS Statistics for Windows 25.0 (IBM Corp, Armonk, NY, USA). A per-protocol analysis was conducted to optimize the evaluation of systemic lidocaine’s effect in patients undergoing laparoscopic colectomy. An intention-to-treat analysis was also performed to confirm these results. For missing primary and secondary outcome data, multiple imputations using chained equations were implemented under a missing at-random assumption, using predictive mean matching for continuous variables and logistic regression for binary data via the R package ‘mice’ (R version 4.3.1, the R Foundation for Statistical Computing Platform). For each missing value, 20 imputations were generated.

Results

From January 16, 2020, to March 24, 2021, 136 patients were initially assessed for eligibility, of whom 126 (92.65%) were included and randomly assigned. After randomization, one patient did not receive a study intervention due to the withdrawal of informed consent. Eight patients who received the study intervention were excluded due to protocol violations or loss of follow-up, leaving 117 for inclusion in the final per-protocol analysis. The CONSORT diagram summarizes the details in Figure 1. Patient demographics and relevant clinical characteristics were comparable between the lidocaine and saline groups (Table 1).

Figure 1. Consolidated Standards of Reporting Trials (CONSORT) flow diagram of the study.

Table 1. Characteristics of participants receiving systemic lidocaine or saline.

	Lidocaine (n = 58)	Saline (n = 59)	p value
Age, yr	60.8 (10.8)	60 (11.4)	0.682
Height, cm	164.5 (6.9)	166.1 (7.9)	0.252
Weight, kg	65 (8.7)	66.6 (7.7)	0.300
BMI, kg/m^2	23.8 (2.3)	24.1 (2.2)	0.446
Sex; male	31 (53%)	33 (56%)	0.787
ASA physical status, n (%)			0.809
I	7 (12%)	8 (14%)
II	51 (88%)	51 (86%)
Duration of operation, min	203 (45)	197 (44)	0.464
Duration of anaesthesia, min	229 (47)	226 (48)	0.757
Preoperative QoR-15 score	132 (125–137)	133 (126–138)	0.633
Type of procedure, n (%)			0.327
Left hemicolectomy	11 (19%)	15 (25%)
Right hemicolectomy	16 (28%)	11 (19%)
Sigmoid resection	24 (41%)	19 (32%)
Rectal resection	2 (3%)	6 (10%)
Transverse colectomy	5 (9%)	8 (14%)
Stoma, n (%)			> 0.99
None	56 (96.6%)	55 (93.2%)
Ileostomy	1 (1.7%)	2 (3.4%)
Colostomy	1 (1.7%)	2 (3.4%)

Note: Data are mean (SD), median (IQR), or number (proportion). ASA, American Society of Anesthesiologists; BMI, body mass index; QoR-15, 15-item Quality of Recovery scale.

As shown in Figure 2, the lidocaine group had higher 24-h QoR-15 global scores (median 120, IQR 111–124) compared with the saline group (median 115, IQR 109–120) in the per-protocol analysis (p = 0.015; median difference 4, 95% confidence interval [CI] 1–6). No difference was seen at 48 h (p = 0.32). Lidocaine was also associated with higher (better) 24-h scores for the QoR-15 pain, physical comfort, and emotional state subscales (all p < 0.05; Supplemental Figure 1A). Only physical comfort remained higher at 48 h (p = 0.033; Supplemental Figure 1B). Similarly, in the intention-to-treat analysis, 24-h global scores were higher with lidocaine (p = 0.012, median difference 4, 95% CI 1–6), while 48-h scores did not differ (p = 0.319).

Figure 2. Beeswarm–Violin plots depict the distribution of the global QoR-15 score preoperatively and 24 h and 48 h postoperatively in patients receiving saline or lidocaine.

Note: Compared with saline, systemic lidocaine improved the quality of recovery-15 scores at 24 hours postoperatively, with a median difference (95% CI) of 4 points (1 to 6), p = 0.015. The violin plot visualizes the distribution shape of the numerical data using kernel density estimation. Circles represent individuals, the solid lines within the boxes of 25th and 75th percentile values depict the median values, and the whiskers symbolize the data within 1.5 times the interquartile range. POD 1, postoperative day 1; POD 2, postoperative day 2.

Compared with saline, patients receiving lidocaine had lower cumulative pain scores over 48 h, reflected by a lower AUC for pain at rest (p = 0.004) and with movement (p = 0.001), as shown in Table 2. Notably, pain NRS scores were significantly lower in the lidocaine group at several postoperative time points, including 0.5, 1, 2, 4, and 8 h at rest and 0.5, 1, 2, and 4 h with movement, as depicted in Figure 3. Intraoperatively, patients who received lidocaine needed less remifentanil (Table 2) but had comparable morphine consumption in the first 48 postoperative hours (Supplemental Figure 2). The intention-to-treat analysis produced a similar result (Supplemental Table 1).

Figure 3. Boxplot for numerical rating scale pain score in patients who received either saline or lidocaine at different time points during rest (A) and movement (B).

Note: In a boxplot, the box represents the interquartile range (IQR), the horizontal line inside the box indicates the median, and the whisker represents the maximum and minimum values within 1.5 times the IQR. Intragroup differences were assessed using the Mann–Whiney U-test. Asterisks indicate statistically significant differences between groups (p < 0.05).

Table 2. Secondary and exploratory outcomes for participants receiving systemic lidocaine or saline.

	Lidocaine (n = 58)	Saline (n = 59)	Relative risk, hazard ratio, or median difference (all 95%CI)	p value
AUCrest of pain NRS to 48 h	80.8 (67.3 to 109.2)	102 (81.8 to 123.3)	−15.5 (−25.5 to −5.0)	0.004
AUCmovement of pain NRS to 48 h	150.7 (138.5 to 182.7)	164.5 (147.0 to 183.8)	−11.5 (−21.0 to −1.7)	0.023
Morphine to 48 h, mg	50 (32 to 64)	52 (38 to 70)	−4 (−12 to 4)	0.344
0–8 h	14 (8 to 20)	18 (10 to 24)	−4 (−6 to 0)	0.043
8–24 h	20 (14 to 24)	20 (14 to 26)	0 (−4 to 2)	0.935
24–48 h	16 (12 to 20)	16 (12 to 20)	0 (–2 to 2)	0.772
Remifentanil consumption, μg	1080 (800 to 1325)	1960 (1500 to 2380)	−840 (−1020 to −660)	< 0.001
Emergence time, min	15 (13 to 18)	14 (12 to 16)	1 (0 to 2)	0.194
Nausea or vomiting to 48 h, n (%)	13 (22%)	16 (27%)	0.89 (0.60 to 1.31)	0.669
Pruritus to 48 h, n (%)	5 (9%)	7 (12%)	0.85 (0.51 to 1.42)	0.563
Dizziness to 48 h, n (%)	3 (5%)	5 (8%)	0.79 (0.45 to 1.40)	0.717
Time to flatus, h	30 (22 to 37)	37 (28 to 49)	2.01 (1.37 to 2.95)	< 0.001
Time to ambulation, h	36 (24 to 46)	41 (31 to 49)	1.34 (0.92 to 1.94)	0.11
Patient satisfaction scores at 48 h	9 (8 to 10)	8 (8 to 10)	0 (0 to 1)	0.097
Type of complication, n (%)
Anastomotic leakage, n (%)	4 (6.9%)	1 (1.7%)	2.60 (0.37 to 0.97)	0.207
Ileus, n (%)	2 (3.4%)	1 (1.7%)	1.53 (0.31 to 7.64)	0.619
Bleeding, n (%)	1 (1.7%)	0	N/A	> 0.99
Pulmonary, n (%)	0	1 (1.7%)	0.50 (0.42 to 0.60)	> 0.99
Intra-abdominal abscess, n (%)	4 (6.9%)	3 (5.1%)	1.19 (0.50 to 2.85)	0.717

Note: Data are median (IQR) or number (proportion). AUC, area under the curve; N/A, not applicable; NRS, numeric rating scale.

The Kaplan–Meier analysis showed that the lidocaine group had a significantly shorter median time to flatus than the saline group. In the per-protocol analysis, patients receiving lidocaine were nearly twice as likely to pass flatus within 72 h postoperatively versus saline (hazard ratio [HR] 2.01, 95% CI 1.37–2.95; log-rank p < 0.001) (Figure 4(A)). Similar results were seen in the intention-to-treat population, with an HR of 1.91 (95% CI 1.33–2.76; log-rank p < 0.001). However, no significant difference was found in the likelihood of ambulation within the first 72 h between groups in the per-protocol analysis (HR 1.34, 95% CI 0.92–1.94; log-rank p = 0.11) (Figure 4(B)) or intention-to-treat analysis (HR 1.31, 95% CI 0.92–1.87; log-rank p = 0.12).

Figure 4. Kaplan–Meier cumulative incidence curves of first flatus (A) and ambulation (B) up to 72 h of follow-up in patients who received either saline or lidocaine.

Note: Tick marks on the curve indicate censored observations.

In the 48 h after surgery, the most common opioid-related side effects were PONV, pruritus, and dizziness in both groups. However, no statistically significant difference was observed between the two groups in the per-protocol analysis (Table 2) or intention-to-treat analysis (Supplemental Table 1). Moreover, we did not observe any lidocaine-related adverse events throughout the study, such as arrhythmia, seizure, tinnitus, or metallic taste.

Discussion

This randomized trial found that systemic lidocaine administration resulted in significantly higher global scores on the QoR-15 questionnaire 24 h postoperatively, reduced intraoperative remifentanil consumption, and accelerated return of gastrointestinal function compared with saline. However, the 4-point improvement in the global QoR-15 score failed to reach the clinically significant threshold. These results suggest that although systemic lidocaine may offer some potential benefits in laparoscopic colorectal resection, it is clinically irrelevant to the quality of recovery from the patient’s perspective.

Recent international concerns have moved to patient-centred outcomes regarding assessing the efficacy of anesthetic and surgical interventions [19]. The QoR-15 questionnaire, validated for reliability, validity, responsiveness, interpretability, acceptability, and feasibility, consists of five dimensions: pain, physical comfort, physical independence, psychological support, and emotional state, and is designed to be user-friendly [20]. Upon comparing these dimensions, it was observed that patients in the lidocaine group had higher scores in pain, physical comfort, and emotional state 24 h after surgery, suggesting a potential advantage of systemic lidocaine. Myles PS and colleagues initially identified the MCID in global QoR-15 scores as 8, later updating this value to 6 in September 2021 [21]. This clinical trial was conducted between January 2020 and March 2021. Despite using the updated MCID of 6, our sample size achieved a statistical power of 82.6% with a Type I error rate of 0.05. Nevertheless, our findings (4-point difference) indicated a statistical but not clinical difference between the two groups in global QoR-15 scores 24 h postoperatively.

The impact of systemic lidocaine on postoperative analgesia following abdominal surgery remains an area of interest. However, previous studies investigating this topic have shown inconsistent results [22–24]. Our findings demonstrated that systemic lidocaine had a minor, transient analgesic effect that was limited to the early postoperative period [25]. Using the integration analysis of pain intensity by AUC, we observed no clinically relevant significant difference between the two groups (with relative differences of 16% at rest and 7% on movement) [26]. Our results resembled the meta-analysis by Katie E et al. [12] but were inconsistent with some previous studies [27,28]. This discrepancy may be partly attributable to differences in lidocaine infusion protocols, surgical factors (e.g. laparoscopic versus open), multimodal analgesia regimens, and patient characteristics between studies. Additionally, patients receiving lidocaine consumed 43% less intraoperative remifentanil, which could decrease their risk of developing opioid-induced hyperalgesia.

The optimal duration for perioperative systemic lidocaine infusion is currently debated. James et al. performed a meta-analysis and concluded that prolonged infusion may not benefit most patients significantly [29]. Theoretically, the standard administration of lidocaine (a bolus of 1.5 mg kg⁻¹ followed by continuous infusion of 2.0 mg kg⁻¹ h⁻¹ until the end of surgery) typically keeps the plasma concentrations below the potential toxic level of 5 µg mL⁻¹ [30]. We subsequently selected this lidocaine infusion protocol, which has demonstrated notable advantages in previous investigations [31,32] and for safety reasons to prevent the potential accumulation of lidocaine.

This study did not identify any significant differences in opioid-related side effects (such as PONV, pruritus, and dizziness) between the groups, likely due to the absence of a significant difference in morphine consumption 48 h after surgery. Regarding gastrointestinal function recovery, we found systemic lidocaine shortened the first flatus time, similar to the research conducted by Kaba A et al. [11] The mechanisms underlying the systemic lidocaine’s beneficial effect on the recovery of gastrointestinal function is multifaceted [33], including modulation of neuroimmune pathways, inhibition of active sodium channel depolarization, and direct impact on smooth muscle cells [34].

The following limitations of our study must be considered. First, we did not measure the plasma concentrations of lidocaine or observe any clinical signs of lidocaine-related adverse events in this study. However, clinicians should monitor closely for toxicity risks with intravenous lidocaine infusion and ensure a lipid emulsion of 20% is readily available [35]. Second, the administration of flurbiprofen axetil and sufentanil may have obscured the effect of systemic lidocaine in our study. We deemed it, however, unethical without any potent analgesic in the immediate postoperative period, especially after intraoperative remifentanil infusion. Third, patients in this study only received a standard intraoperative lidocaine protocol used at our institution, consisting of a 1.5 mg kg⁻¹ intravenous bolus over 10 min followed by continuous infusion at 2 mg kg⁻¹ h⁻¹ until completion of surgery. The potential effects of different lidocaine dosing regimens or prolonged administration on outcomes after laparoscopic colorectal resection should be further examined. Fourth, the enrollment was restricted to relatively healthy patients (ASA physical status I or II), restricting this study’s generalizability.

Conclusion

In patients undergoing laparoscopic colorectal resection, intraoperative intravenous lidocaine infusion resulted in minor improvements in the quality of recovery that were unlikely to be clinically meaningful based on the validated patient-reported outcome measure (QoR-15). Careful individual risk-benefit evaluation remains imperative for tailoring multimodal analgesia regimens until further data elucidate the role of perioperative lidocaine.

Authors contributions statement

Wenjun Lin: Conceptualization, Methodology, Project administration, Investigation, Writing-review and editing.Ying Yang: Conceptualization, Investigation, Data curation, Visualization, Formal analysis. Yifen Zhou: Methodology, Investigation, Formal analysis, Writing-original draft. Chunlin Qiu: Investigation, Writing-original draft. Yanhua Guo: Conceptualization, Investigation, Validation, Project administration, Writing-review and editing. Yusheng Yao: Conceptualization, Resources, Supervision, Validation, Writing-review and editing. All authors read and gave final approval of the version to be published.

Ethical approval statement

The Ethics Committee of Fujian Provincial Hospital, Fuzhou, China approved the study protocol on October 10, 2019 with the identification number K2019-10-003.

Acknowledgments

We gratefully acknowledge Dr Fangqin Xue and Dr Liangxiang Huang (Department of Gastrointestinal Surgery, Fujian Provincial Hospital) for their kind support. This study was supported by Natural Science Foundation of Xiamen, China (grant number 3502Z202374068), the Medical Innovation Project of Fujian Province (No. 2022CXA007), and Natural Science Foundation of Fujian Province (No. 2021J01378).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The individual de-identified participant data supporting published results, the study protocol, and the statistical analysis plan are available from the corresponding author upon reasonable request.