Questions · Supraclavicular Brachial Plexus Block
12 questions, 0 approved. Approve them one at a time — a quiz shows nothing you have not.
Recall — derived from a kept point
A prospective observational study followed 6366 ultrasound-guided periclavicular brachial plexus blocks for clinically manifest, radiologically confirmed pneumothorax. Give the rate, compare it with the pre-ultrasound figure, and state the detail about timing that changes what you tell a day-case patient.
Answer: Four patients had a symptomatic, radiologically confirmed pneumothorax — 0.06% (95% CI 0.001 to 0.124) — against a historical rate reported as high as 6.1% without ultrasound monitoring. The detail that matters is that three of the four presented after a two-day latency period. A pneumothorax from a supraclavicular block is not reliably apparent before the patient goes home, so discharge advice has to name breathlessness and pleuritic chest pain over the following days as reasons to seek help, rather than relying on a normal immediate recovery.
A complication with a delayed presentation is a communication problem as much as a technical one. Note too that all the anaesthetists involved in these four complications had previously performed fewer than 20 of these blocks, though the study could not confirm an experience of 20 blocks or fewer as a statistically significant risk factor.
Source claim: In a prospective observational study of 6366 ultrasound-guided periclavicular brachial plexus blocks, clinically symptomatic radiologically confirmed pneumothorax occurred in four patients (0.06%, 95% CI 0.001-0.124), three of them after a two-day latency period, against a reported risk as high as 6.1% without ultrasound monitoring; all of the anaesthetists involved in the complications had previously performed fewer than 20 blocks, although the authors were not able to confirm that an experience of 20 blocks or fewer is a significant risk factor.
Gauss A et al., Incidence of clinically symptomatic pneumothorax in ultrasound-guided infraclavicular and supraclavicular brachial plexus block, Anaesthesia 2014
recall · CA-2 · phrased by llm
A meta-analysis of 12 randomised trials compared supraclavicular with interscalene brachial plexus block for shoulder surgery. Describe what it found for analgesia and for the three adverse effects it examined, and say how firmly you can act on it.
Answer: Analgesia was comparable: 24-hour pain scores differed by -0.34 (95% CI -0.75 to 0.07) and morphine equivalent consumption by 1.84 mg per 24 hours (95% CI -0.00 to 3.69), neither reaching significance. On adverse effects the supraclavicular approach was better for two of the three — hemidiaphragmatic paresis risk ratio 0.56 (95% CI 0.39 to 0.82) and Horner's syndrome risk ratio 0.29 (95% CI 0.19 to 0.44) — with no significant difference in hoarseness (risk ratio 0.73, 95% CI 0.48 to 1.13). How firmly can you act on it? Not very: the authors' own wording is that the supraclavicular approach might be an efficient alternative, but that the available evidence is inadequate and prevents a firm conclusion. Read the numbers at their true strength — a risk ratio of 0.56 is a reduction in hemidiaphragmatic paresis, not abolition of it, and the meta-analysis reports no respiratory outcomes in patients with limited respiratory reserve, so it cannot tell you how the two blocks behave in the patient for whom that reduction would matter most.
"Fewer adverse effects, equal analgesia, inadequate evidence" is a common shape in regional anaesthesia meta-analyses. Read the reviewers' own confidence statement before you change practice on the point estimate.
Source claim: Pooling 12 randomised trials of shoulder surgery, the supraclavicular approach gave comparable 24-hour pain scores (mean difference -0.34, 95% CI -0.75 to 0.07) and morphine equivalent consumption (1.84 mg per 24 hours, 95% CI -0.00 to 3.69) to the interscalene block, with a lower rate of hemidiaphragmatic paresis (risk ratio 0.56, 95% CI 0.39-0.82) and Horner's syndrome (risk ratio 0.29, 95% CI 0.19-0.44) and no significant difference in hoarseness (risk ratio 0.73, 95% CI 0.48-1.13); the authors conclude that the supraclavicular approach might be an efficient alternative to the interscalene approach for shoulder surgery, but that the available evidence is inadequate and prevents a firm conclusion.
Schubert AK et al., Interscalene versus supraclavicular plexus block for the prevention of postoperative pain after shoulder surgery: A systematic review and meta-analysis, Eur J Anaesthesiol 2019
recall · CA-2 · phrased by llm
This meta-analysis found that a supraclavicular brachial plexus block reduced the incidence of hemidiaphragmatic paralysis by ___% compared with conventional interscalene blockade in adults undergoing shoulder surgery.
Answer: 46
This meta-analysis found that a supraclavicular brachial plexus block reduced the incidence of hemidiaphragmatic paralysis by 46% compared with conventional interscalene blockade in adults undergoing shoulder surgery.
Hemidiaphragmatic paralysis after ultrasound-guided brachial plexus blocks for shoulder surgery: A systematic review and meta-analysis of randomized clinical trials · PMID 40494113
recall · CA-2 · phrased by derived
This randomized controlled non-inferiority trial found that the intertruncal approach to supraclavicular block failed to prove non-inferiority to the classical approach for complete sensory blockade at ___ min, and was associated with inferior musculocutaneous blockade, longer performance time, and higher hemidiaphragmatic paresis incidence.
Answer: 20
This randomized controlled non-inferiority trial found that the intertruncal approach to supraclavicular block failed to prove non-inferiority to the classical approach for complete sensory blockade at 20 min, and was associated with inferior musculocutaneous blockade, longer performance time, and higher hemidiaphragmatic paresis incidence.
Intertruncal versus classical approach to supraclavicular brachial plexus block on sensory-motor blockade for upper extremity surgery: a randomized controlled non-inferiority trial · PMID 40740147
recall · CA-2 · phrased by derived
This meta-analysis found no significant difference between ultrasound-guided axillary and supraclavicular blocks in adequate surgical anesthesia at ___ minutes, block performance time, or onset time for distal upper limb surgery.
Answer: 30
This meta-analysis found no significant difference between ultrasound-guided axillary and supraclavicular blocks in adequate surgical anesthesia at 30 minutes, block performance time, or onset time for distal upper limb surgery.
Axillary Brachial Plexus Block Compared with Other Regional Anesthesia Techniques in Distal Upper Limb Surgery: A Systematic Review and Meta-Analysis · PMID 38892896
recall · CA-2 · phrased by derived
This meta-analysis of 18 RCTs found that supraclavicular blocks had a lower success rate than infraclavicular blocks (OR 0.61, ___% CI 0.41–0.91) and a higher rate of Horner's syndrome.
Answer: 95
This meta-analysis of 18 RCTs found that supraclavicular blocks had a lower success rate than infraclavicular blocks (OR 0.61, 95% CI 0.41–0.91) and a higher rate of Horner's syndrome.
Supraclavicular versus infraclavicular brachial plexus block in upper limb orthopaedic surgery: a systematic review and meta-analysis of randomised controlled trials · PMID 39287814
recall · CA-2 · phrased by derived
This randomized trial found that administering ___ mg/kg of intravenous dexamethasone before supraclavicular brachial plexus blockade for wrist and hand surgery reduced the incidence of rebound pain from 79% to 32% and decreased 24-hour cumulative opioid consumption.
Answer: 0.11
This randomized trial found that administering 0.11 mg/kg of intravenous dexamethasone before supraclavicular brachial plexus blockade for wrist and hand surgery reduced the incidence of rebound pain from 79% to 32% and decreased 24-hour cumulative opioid consumption.
The effect of intravenous dexamethasone on rebound pain after wrist and hand surgery under supraclavicular brachial plexus blockade: a randomized placebo-controlled trial · PMID 40542311
recall · CA-2 · phrased by derived
The point with one number taken out. No model wrote any of this: the stem is the sentence you reviewed, minus a digit, and the paper it came from is named beneath it.
Open prompts
How does your plan change if the patient is not optimised?
open · CA-2 · phrased by derived
What is the physiology behind what we just did?
open · CA-2 · phrased by derived
Talk me through the trade-off you made there.
open · CA-2 · phrased by derived
What would make you abandon this plan and do something else?
open · CA-2 · phrased by derived
Questions only — nothing here asserts anything, which is why a model is allowed to phrase them. Where no model was reachable these are the level defaults.