Analgesic efficacy of bilateral continuous transversus abdominis plane blocks using an oblique subcostal approach in patients undergoing laparotomy for gynaecological cancer: a prospective, randomized, triple-blind, placebo-controlled study  T. Yoshida, K. Furutani, Y. Watanabe, N. Ohashi, H. Baba  British Journal of Anaesthesia  Volume 117, Issue 6, Pages 812-820 (December 2016) DOI: 10.1093/bja/aew339 Copyright © 2016 The Author(s) Terms and Conditions

Fig 1 The transducer position and pathway of the oblique subcostal transversus abdominis plane (TAP) block. (a) Blue rectangles and dotted lines indicate the transducer and typical distribution of the anterior branches of spinal nerves, respectively. The transducer was initially placed near the xiphoid process and parallel to the costal margin (b) and was then moved towards the anterior border of the iliac crest (c–e). The letters indicate the transducer position when the corresponding ultrasound images were obtained. The filled triangles indicate the TAP. (b) The TAP is located beneath the rectus abdominis muscle. (c) The TAP is located beneath the rectus abdominis muscle and continuous with beneath both the aponeurosis of the linea semilunaris and the internal oblique muscle. (d) The TAP is located beneath the internal oblique muscle. (e) The TAP is located beneath the internal oblique muscle near the iliac crest. ALS, aponeurosis of linea semilunaris; EOM, external oblique muscle; IC, iliac crest; IOM, internal oblique muscle; RAM, rectus abdominis muscle; TAM, transversus abdominis muscle. British Journal of Anaesthesia 2016 117, 812-820DOI: (10.1093/bja/aew339) Copyright © 2016 The Author(s) Terms and Conditions

Fig 2 An ultrasound image strip of the catheter in the transversus abdominis plane (TAP). The TAP was dilated using local anaesthetic. The catheter (filled triangles) entered into the TAP between the rectus abdominis and transversus abdominis muscles, passed beneath the aponeurosis of the linea semilunaris, continued in the TAP beneath the internal oblique muscle, and terminated at the TAP near the iliac crest. ALS, aponeurosis of linea semilunaris; EOM, external oblique muscle; IC, iliac crest; IOM, internal oblique muscle; RAM, rectus abdominis muscle; TAM, transversus abdominis muscle. British Journal of Anaesthesia 2016 117, 812-820DOI: (10.1093/bja/aew339) Copyright © 2016 The Author(s) Terms and Conditions

Fig 3 The catheters inserted into the bilateral transversus abdominis planes. Two catheters are bilaterally inserted near the xiphoid process and costal margin and placed within the bilateral transversus abdominis planes along an oblique subcostal line toward the anterior border of the iliac crests. Dotted lines indicate the catheters lying within the transversus abdominis planes. The catheter tip is located in the transversus abdominis plane nearby the iliac crest at the level of the midaxillary line. British Journal of Anaesthesia 2016 117, 812-820DOI: (10.1093/bja/aew339) Copyright © 2016 The Author(s) Terms and Conditions

Fig 4 CONSORT flow diagram. British Journal of Anaesthesia 2016 117, 812-820DOI: (10.1093/bja/aew339) Copyright © 2016 The Author(s) Terms and Conditions

Fig 5 Time course of cumulative morphine consumption. The 95% confidence intervals of the difference in the median values of cumulative morphine consumption (in milligrams per kilogram) at each time point after transversus abdominis plane (TAP) catheter placement are as follows: 1 h, −0.02 to 0.00 (P = 0.22); 4 h, −0.04 to 0.01 (P = 0.36); 12 h, −0.14 to 0.00 (P = 0.049); 24 h, −0.30 to − 0.03 (P = 0.01); 36 h, −0.36 to − 0.01 (P = 0.03); and 48 h, −0.41 to − 0.01 (P = 0.03). R and N indicate the Rop group and the NS group, respectively. The horizontal lines indicate the medians; boxes indicate interquartile ranges; and whiskers indicate ranges. The P-values were calculated using the Mann–Whitney U-test. British Journal of Anaesthesia 2016 117, 812-820DOI: (10.1093/bja/aew339) Copyright © 2016 The Author(s) Terms and Conditions