A Randomised Controlled Trial of Ultrasound-Assisted Spinal Anaesthesia

Abstract

Pre-procedural ultrasound scanning has been used to facilitate spinal anaesthesia in patients with difficult anatomical landmarks and shown to improve first-attempt success rates in some studies. We studied whether pre-procedural ultrasound scanning improved first-attempt success rate and decreased time taken for the procedure in the general adult population. In this prospective, randomised controlled trial, 170 American Society of Anesthesiologists physical status 1 to 3 patients aged between 21 and 80 years were recruited. Informed consent was obtained. Patients were randomised into two groups, ultrasound-guided identification of landmarks (Ultrasound Group) and manual palpation of landmarks (Manual Palpation Group). The primary outcome was first-attempt success rate and secondary outcomes were time taken to perform procedure, number of needle redirections, patient satisfaction and complications. The first-attempt success rate was 64% in the Ultrasound Group and 52% in the Manual Palpation Group (P=0.16). Time taken for procedure was shorter in the Ultrasound Group compared to the Manual Palpation Group (2.9±3.6 minutes versus 3.9±3.7 minutes, P= 0.007). Patient satisfaction was higher in the Ultrasound Group. There were no differences in complications. As there was no statistically significant difference in first-attempt success rates between the two groups, existing evidence for routine pre-procedural scanning for all patients is inadequate. The current use of pre-procedural ultrasound scanning will probably be limited to selected patients where spinal anaesthesia may be technically challenging with conventional methods.

Lumbar Neuraxial Ultrasound for Spinal and Epidural Anesthesia

“…[27][28][29]34 Since a previous review, 43 more data have become available for non-obstetric patients 22,25,26,33,37,[39][40][41] and for patients presumed at risk for difficult insertion due to obesity, scoliosis, or previous surgery. 33 These special patient populations are clinically important because they are at increased risk for technical difficulty.…”

“…Fourteen RCTs involving 1768 patients [27][28][29][32][33][34][35][36][37][38][39][40][41][42] (Table 4) and 5 prospective cohort studies involving 227 patients [20][21][22]25,26 examined efficacy and safety outcomes. Eight RCTs [27][28][29]32,34,36,38,42 and 2 cohort studies 20,21 evaluated epidural analgesia in obstetric patients, whereas 3 RCTs 33,37,39 and 2 cohort studies 22,26 evaluated spinal anesthesia in orthopedic procedures.…”

A randomised controlled trial comparing needle movements during combined spinal‐epidural anaesthesia with and without ultrasound assistance

“…Ultrasound‐assisted neuraxial techniques may facilitate central neuraxial blockade by improving technical performance assessed by the number of needle movements , patient experience and quality of analgesia . Potential risks occur when placement of central neuraxial blockade is more cephalad than intended , which may be compounded by a spinal cord extending more caudad than expected , and an intercristal line that is an unreliable landmark in obesity and pregnancy .…”

Comparison of Ultrasound‐guided vs. Standard Landmark Techniques for Training Novice Operators in Placing Needles Into the Lumbar Subarachnoid Space of Canine Cadavers

“…Some recent human studies suggest a limited interest for experienced operators of the use of ultrasound guidance for lumbar spinal puncture in unselected patients . However, according to some authors, time and number of attempts were improved with ultrasound guidance also in expert operators and ultrasound has been suggested as a preprocedural technique to predict the difficulty of the needle placement into the lumbar subarachnoid space . Authors do not suggest the use of ultrasound guidance for all needle placements into the lumbar subarachnoid space in a clinical setting but propose that it may be useful as a “rescue” technique for difficult punctures based on conclusions in several human studies …”