Thread by @OBsleepmerchant

@antonchau1 kicks off the #SolShnider track 3 with DPE vs other #OBAnes neuraxial techniques. #SOAPAM2023

The selection of labour analgesia options, all catheter based and similar with slight differences. Value propositions of DPE: confirmation, translocation and improved safety - value over EPL and CSE. #SOAPAM2023

Value proposition 1: confirmation. #DPE adds visual confirmation to LOR - midline and epidural tip.

Why do #OBAnes get equivocal LOR? There’s an anatomic basis. #SOAPAM2023

Anatomic basis: interspinous ligament midline gaps. Ligamentum Flavum midline gap due to incomplete fusion leading to absence of crisp LOR. #OBAnes #SOAPAM2023

Incidence of Ligamentum Flavum midline gaps, varies by level. DPE confirms location decreasing risk of catheter failure. Data from CSE’s. #OBAnes #SOAPAM2023

What about #DPE? Thomas et al @_Anesthesiology 2005: absence of CSF increases risk of replacement. #OBAnes #SOAPAM2023

Arnolds et al @IJOA_Journal: No CSF 3 fold increase in catheter failure rate #OBAnes #SOAPAM2023

Berger et al @IJOA_Journal: #DPE lower failure, lower replacement. No difference in failure around initiation, but less failure during maintenance phase. #DPE longer catheter survival times. #OBAnes #SOAPAM2023

Coming soon: multicentre retrospective cohort study (@emilysharpe) - what are risks of failed catheter conversion to surgical anesthesia for cesarean delivery? Data being collected… #OBAnes #SOAPAM2023

#DPE value proposition #2: Translocation. @Anaes_Journal incl @MarcVandeVelde6 meta-analysis CSE vs epidural: unilateral block reduced after CSE. Transdural flux compensates for non-uniform spread? Mechanistic evaluation. #OBAnes #SOAPAM2023

Translocation dependent on size of dural puncture. 27G too small. 25/26G #DPE superior to epidural. #OBAnes #SOAPAM2023

#DPE @antonchau1 in @IARS_Journals: Translocation speeds onset. Improves asymmetrical sensory block. Improves bilateral S2 block. #OBAnes #SOAPAM2023

Physician epidural top-ups, equivalent of breakthrough pain, lower with #DPE. With CSE, transition from spinal to epidural interpreted as breakthrough pain (is my experience). Translocation harnesses spinal and epidural spaces. #OBAnes #SOAPAM2023

#DPE value proposition #3: improve safety profile compared to CSE. CSE very rapid onset which may have consequences. More pruritis with CSE. Transient fetal bradycardia associated with CSE, NOT lead to higher cesarean section rate, but worse neonatal outcomes. Exact mechanism… twitter.com/i/web/status/1…

Okay, practical considerations for #DPE. Not need new kit, likely have what’s required. Note: needle deflection (especially 26/27G - false dry tap, wait). Shearing metal fragments is NOT a concern. #OBAnes #SOAPAM2023

Protrusion of spinal needle beyond tip of Epidural needle is important - preferably >13mm (15mm+?). Compare needles in your own setting? #OBAnes #SOAPAM2023

Barriers to implementation: perceived lack of benefits & perceived risks. Risk of PDPH for CSE and epidural same - #DPE similar? Need larger studies. #OBAnes #SOAPAM2023

Another Barrier to clinical adoption = conflicting evidence #OBAnes #SOAPAM2023

@_Anesthesiology 2022 looked at Obese parturients. No significant difference between #DPE and epidural. @antonchau1 demonstrates the PIEB effect. #OBAnes #SOAPAM2023

Song et al @IARS_Journals suggests synergism between #DPE and PIEB. #OBAnes #SOAPAM2023

Target mismatch: #DPE may be beneficial in specific situations, difficult to demonstrate in RCT. Matching the value of DPE to target situations, including faster conversion to surgical block? #OBAnes #SOAPAM2023

@antonchau1 acceptably excited with #SOAPAM2023 best paper abstract. Statistically faster vs. clinically faster onset? #OBAnes

Summary. Maximize success. One size will not fit all. @antonchau1 believes residents/registrars should be taught all 3 techniques. Their use is a balance of culture, experience and context. #OBAnes #SOAPAM2023

And what about future directions? Refine and improve neuraxial initiation techniques. #OBAnes #SOAPAM2023

@threadreaderapp unroll please