Ultrasound guided quadratus lumborum block or posterior transversus abdominis plane block catheter infusion as a postoperative analgesic technique for abdominal surgery.

Sir,

Continuous catheter infusion of transversus abdominis plane (TAP) block provides as satisfactory analgesia as epidural in the postoperative period for abdominal surgery.[12] Single shot ipsilateral quadratus lumborum (QL) block has been reported to provide effective analgesia for 24 h.[3] A case of continuous unilateral QL block was reported in pediatric surgery.[4] This is the first report of continuous bilateral use in an adult laparotomy.

An 89-year-old man presented for open right hemi colectomy with a midline incision. His co-morbidities were sick sinus syndrome and one recovered episode of mini stroke. His physical examination and investigations were unremarkable. A written informed consent was obtained for QL block infusion as part of multimodal analgesia. He was administered a standard uneventful general anesthesia. The peri-operative fentanyl used was 300 mcg in the operating room and 200 mcg in the recovery room. After the surgical procedure he was positioned supine with lateral tilt to administer QL block under the ultrasound (Sonosite Inc., Bothel, WA, USA) guidance. An 18 gauge Touhy's epidural needle was used to reach the junction of TAP and QL muscle. Normal saline 5 mL was used to identify that plane. A volume of 20 ml of 0.5% of Ropivacaine (Naropin-Astra Zeneca Sydney, NSW, Australia) bolus was injected in that plane just over QL [Figure 1]. This was followed by epidural catheter insertion to facilitate continuous infusion [Figure 2]. A similar technique was performed on the other side. A continuous infusion of 0.2% Ropivacaine at 5 ml/h was delivered by ‘On Q pain relief system’ pain buster pump (Kimberly Clark CA USA). On the pain scale of 0-10, the 1st h dynamic pain scores were 6 on arrival and reduced to 2 after 1 hr stay in recovery. The day 1 and day 2 dynamic pain scores were between 1 and 2. He was administered paracetamol- 1 g qid and tramadol- 100 mg tid. The only rescue medication used for 48 h was 10 mg of oxycodone. This QL block infusion has the advantage of covering pain arising from long incisions such as supra and infra umbilical regions without requiring multiple catheters. This could be due to spread of LA from QL and Psoas muscles to the paravertebral space covering more segments possibly from T4 to L2. Many case series or trials need to be conducted before confirming its efficacy.

Figure 1

Ultra sound image of the QL block with LA. EO = external oblique, IO = internal oblique, QL = Quadratus lumborum

Figure 2

Lateral tilt position QL block with secured catheter

In conclusion, ultrasound guided QL catheter infusion had low pain scores with minimal use of opioid analgesia without any complication.