Ortiz 2016.
| Methods | Multicentric, double‐blind, randomized, and placebo‐controlled trial. This trial aimed to compare postoperative analgesia, opioid consumption, duration of ileus and hospital stay, and cytokine levels in patients undergoing laparoscopic cholecystectomies who received intravenous lidocaine in comparison with a control group. The study was conducted in Brazil from July 2013 to February 2014. (NCT02363699) |
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| Participants | Number assessed for eligibility:87 Number randomized: 44→ 22:22 Number analysed: 43→ 21:22 Inclusion criteria patients scheduled to undergo elective laparoscopic cholecystectomy, 18 years and older, ASA I and II Exclusion criteria Patients older than 75 years, patients with heart disease, and patients with history of kidney failure, liver failure, psychiatric disorder, chronic use of opioids, or medications that could cause induction of liver enzymes (anticonvulsants) were not included in the study. In addition, the presentation of adverse effects during the intervention or postoperative complications, and the conversion to open surgery were used as exclusion criteria. Baseline details Experimental group (n = 22) Mean age (years): 43.77, SD = 12.55 M = 22,7%, F = 77,3% Mean weight(kg): 76.91, SD = 16.41 ASA I/II (n): NA Mean duration of anaesthesia (min): N/A Mean duration of surgery (min): 105.23, SD = 38.25 Main surgical procedures (n): elective laparoscopic cholecystectomy (21) Control group (n = 22) Mean age (years): 46.09, SD = 11.50 M = 40,9%, F = 59,1% Mean weight (kg): 86.86, SD = 19.76 ASA I/II (n): NA Mean duration of anaesthesia (min): N/A Mean duration of surgery (min): 112.50, SD = 47.58 Main surgical procedures (n): elective laparoscopic cholecystectomy (22) |
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| Interventions |
Experimental group (22 patients) Lidocaine was administered in bolus of 1.5 mg/kg at the start of the procedure and maintained at a dose of 3 mg/kg/h until 1 hour after the end of the surgery. A solution of 0.3 % lidocaine was used, so that the infusion rate was equal to the patient's weight. Answer from author upon request: lidocaine infusion started before incision Control group (22 patients) Saline solution was administered in the control group with the same infusion rates |
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| Outcomes | The primary endpoint of the study was pain within the first 24 hrs. Dichotomous
Continuous
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| Notes |
Medication During surgery, all patients received 4 mg ondansetron for prophylaxis of nausea and vomiting and dipyrone 30 mg/kg, 30 minutes before the end of the procedure. Postoperatively, patients received dipyrone 1 g IV every 6 hours and ondansetron 8 mg IV every 8 hrs. For patients who reported pain at rest equal or greater than 4, morphine titration was started with 1 mg increments every 5 minutes until the pain was reported as less than 4. At this point, patients were encouraged to manage their own medication. The patient‐controlled analgesia pumps were programmed to bolus of 4 ml (morphine solution 0.5 mg/ml) followed by 8 minutes of security lock between doses. The maximum dose in 4 hrs was 30 mg. No continuous maintenance dose of morphine was used in the postoperative period. Fifteen percent increases in mean arterial pressure or heart rate values greater than 100 beats/min, with bispectral index between 40 and 60, allowed for supplementary administration of 5 μg sufentanil. Anaesthesia The anaesthesia regime was standardized in both groups. Funding No external funding source was used. |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: “randomization was performed by a computer program (random.org) that generated a random number sequence from 1 to 44, divided into 2 columns. “ |
| Allocation concealment (selection bias) | Unclear risk | Quote: “an employee of the Surgical Center pharmacy, previously trained for that, appointed each column with a group (lidocaine and placebo) and stored the results in 44 envelopes. “ From the description of the text is it unclear if the allocation was fully concealed. |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Quote: “this same collaborator was responsible for preparing the solutions according to the dilution protocol. These solutions were kept in identical color and volume containers for both groups and were provided just before anesthetic induction.” Quote: “The study was double blind. Patients were not informed about the solution they were receiving. Likewise, both the research team and the auxiliary anesthetists were unaware of which group each patient belonged to.” |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: “the study was double blind. Patients were not informed about the solution they were receiving. Likewise, both the research team and the auxiliary anesthetists were unaware of which group each patient belonged to.” |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Dropout rate (experimental/control): 5%:0% Quote: “the patients who had hospital discharge before 24 hours were asked to wait until the final pain assessment and blood collection. In this way, we avoided losses and all the data were included in the analysis.” Quote: “the lidocaine group lost one patient who had his surgery converted due to problems during the procedure. All patients who started receiving lidocaine continued the infusion according to the protocol.” Reasons for missing data (1 patient) are unlikely to be related to true outcome. |
| Selective reporting (reporting bias) | Unclear risk | The study protocol is available and the primary outcome as well as some secondary outcomes have been reported. The secondary outcomes “length of hospital stay” and “time to first flatus” have not been prespecified. The protocol has been retrospectively registered (4 February 2015) (NCT02363699). |
| Other bias | Low risk | The study appears to be free of other sources of bias. |