Post‐operative analgesia using intermittent vs. continuous adductor canal block technique: a randomized controlled trial

Abstract

Intermittent ACB allowed significantly reduced consumption of morphine for 24 h in the post-operative period compared with continuous ACB when identical doses of ropivacaine were used in each group.

Basal infusion versus intermittent boluses for perineural catheters: should we take the ‘continuous’ out of ‘continuous peripheral nerve blocks’?

“…Unfortunately, this strategy also failed to demonstrate any benefits compared with equivalent-dose basal infusions for both transversus abdominis plane (24 mL boluses) and adductor canal (21 mL boluses) catheters 13 14. One contrasting RCT reported decreased pain scores and opioid requirements in subjects with intermittent boluses undergoing anterior cruciate ligament reconstruction with adductor canal catheters: subjects received 0.5% ropivacaine either as a 2.5 mL/hour basal infusion or 15 mL bolus doses every 6 hours 15. However, these findings may not demonstrate the superiority of intermittent boluses so much as the inferiority of a suboptimal basal infusion: continuous adductor canal blocks appear to require a higher basal rate of local anesthetic than their femoral counterparts16—even with a relatively high rate of 8 mL/hour, local anesthetic spread remains somewhat limited 17.…”

Programmed Intermittent Boluses of Ropivacaine may Provide Superior Analgesia Compared with Continuous Infusion via Paravertebral Catheters following Thoracic Surgery

“…Our results may differ from these findings for two reasons. Firstly, many studies have previously documented that volume may be more important than concentration [17][18][19][20]36]. Secondly, our patients received boluses more frequently than six-hourly, leading to more frequent delivery of LA into the extrapleural paravertebral space.…”

“…Secondly, our patients received boluses more frequently than six-hourly, leading to more frequent delivery of LA into the extrapleural paravertebral space. Català et al (1996) The use of PIB has also been previously investigated in other peripheral nerve catheters with varying results, including adductor canal blocks [18,23,24], femoral nerve blocks [17,25], popliteal nerve blocks [19,20], interscalene blocks [26,36], infraclavicular blocks [27] and transverse abdominal plane blocks [28]. Of these, five showed an improvement with the use of PIB when compared with continuous infusion, while six showed no difference and none showed inferiority.…”

“…With the increasing availability of infusion pumps with the technology to administer programmed intermittent boluses (PIB), there has been growing interest in determining if there is any benefit from this technique. Whilst superior analgesia with programmed intermittent boluses, particularly with catheters in the epidural [13][14][15][16], femoral [17], adductor canal [18] and popliteal spaces [19,20], has been demonstrated, other authors have shown no improvement with automated boluses [21][22][23][24][25][26][27][28]. This may reflect variations in anatomical structures or differences in protocols, in particular, LA bolus volume and frequency.…”

Continuous Transversus Abdominis Plane Nerve Blocks: Does Varying Local Anesthetic Delivery Method—Automatic Repeated Bolus Versus Continuous Basal Infusion—Influence the Extent of Sensation to Cold?: A Randomized, Triple-Masked, Crossover Study in Volunteers

“…33 Supporting this theory is that a positive study demonstrating a benefit of intermittent boluses versus a basal infusion for ultrasound-guided perineural catheters involved the adductor canal location: ropivacaine 0.5% delivered as 15 mL boluses every 6 hours or a 2.5 mL/h basal. 19 However, considering there is evidence that adductor canal infusions require a relatively high basal rate to provide adequate analgesia, 34,35 this study might reflect an inadequate basal infusion rate rather than a clinically-relevant benefit of repeated bolus doses. An additional positive study involving ultrasound-guided femoral catheters was nominally positive (intermittent bolus over continuous basal); 20 yet, while the differences between treatments reached statistical significance for some variables—without any correction for multiple comparisons—they failed to reach clinical significance.…”