Evidence on whether the use of deep neuromuscular block (NMB) influences postoperative pain after laparoscopic surgery is limited, and existing studies have shown conflicting results. We studied the effect of the depth of NMB during laparoscopic gastrectomy on postoperative pain.
The aim of this study was to evaluate the effect of depth of NMB during laparoscopic gastrectomy on postoperative pain by allocating patients randomly to either deep or moderate NMB with a standard-pressure pneumoperitoneum.
A randomised, controlled, double-blind study.
A university-affiliated hospital.
One hundred patients.
Patients were allocated randomly to receive either deep (posttetanic count 1 to 2) or moderate (train-of-four count 1 to 2) levels of NMB. Following surgery, the patients were asked to rate their pain every 10 min using a visual analogue scale (VAS) (0 = no pain, 10 = most severe pain) in the postanaesthesia care unit (PACU). Patients received intravenous oxycodone, 2 mg every 10 min, until the pain intensity (VAS) had decreased to less than 3 at rest and less than 5 on wound compression, at which point the minimum effective analgesia dose (MEAD) of oxycodone was determined.
The primary endpoint was the MEAD of oxycodone. Secondary endpoints included area under the curve of VAS for wound pain, VAS scores for wound and shoulder pain at 6 and 24 h after the end of surgery, rescue analgesics, a five-point surgical rating scale, Rhodes index of nausea vomiting retching at 6 and 24 h after the end of surgery and duration of pneumoperitoneum.
The median value for the MEAD of oxycodone was 8 mg in both groups. Area under the curves of VAS over time were similar in both groups. Variables associated with postoperative pain including mean VAS at PACU and frequency of rescue analgesics in the ward did not differ significantly between the two groups. The duration of pneumoperitoneum was a significant variable in determining the MEAD of oxycodone (linear regression, R2 = 0.07, P = 0.008). The number of patients who reached the acceptable surgical score was not significantly different between the two groups. However, the moderate NMB group did have a significantly higher proportion of cases that required additional muscle relaxants (P < 0.001).
Deep, compared with moderate, NMB did not significantly reduce the MEAD of oxycodone administered in the PACU. The duration of pneumoperitoneum was positively correlated with the MEAD.
ClinicalTrials.gov identifier: NCT03266419.
From the Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul (C-BM, L-YH, N-GJ), Department of Anesthesiology and Pain Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan (K-SH), Department of Surgery (G-CS, K-HS, L-IS, K-BuS, K-ByS) and Department of Clinical Pharmacology and Therapeutics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea (N-GJ)
Correspondence to Byung-Moon Choi, MD, PhD, Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea Tel: +82 2 3010 1704; fax: +82 2 3010 6790; e-mail: email@example.com
Published online 9 September 2019
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