Questions · Scalp Blocks
11 questions, 0 approved. Approve them one at a time — a quiz shows nothing you have not.
Recall — derived from a kept point
In the randomised, placebo-controlled trial that compared scalp block, local infiltration at the pin sites, and routine anaesthesia alone for skull-pin insertion, name the nerves the scalp block covered and state what the trial measured beyond blood pressure and heart rate.
Answer: The block covered the supraorbital, supratrochlear, auriculotemporal, occipital and postauricular branches of the greater auricular nerves, using 20 ml of 0.5% bupivacaine. Beyond haemodynamics the trial measured the endocrine stress response — plasma cortisol and adrenocorticotropic hormone, sampled 5 minutes before induction and 5 and 60 minutes after the pin holder went on. Heart rate and mean arterial pressure rose during pinning in the infiltration and control groups but not in the scalp block group, and cortisol and ACTH at both post-pinning time points were significantly lower after the scalp block than after either infiltration or routine anaesthesia.
Infiltration at the pin sites was not equivalent to the block: on both haemodynamics and stress hormones the block did better, and that is what the authors conclude. Why it did better is not something this trial tested. The familiar account — that a field block of the named nerves is less dependent on each pin landing exactly where you infiltrated — is an explanation offered for the result rather than a finding of it.
Source claim: In 45 ASA I-II patients randomised to scalp block with 20 ml of 0.5% bupivacaine blocking the supraorbital, supratrochlear, auriculotemporal, occipital and postauricular branches of the greater auricular nerves, to pin-site infiltration, or to routine anaesthesia, heart rate and mean arterial pressure rose significantly during head pinning in the infiltration and control groups but not the scalp block group; plasma cortisol and adrenocorticotropic hormone, sampled 5 minutes before induction and 5 and 60 minutes after pin-holder insertion, were significantly lower after the scalp block at both post-pinning time points, and the authors conclude that scalp block blunts the haemodynamic and stress responses to head pinning better than routine anaesthesia or scalp infiltration.
Geze S et al., The effect of scalp block and local infiltration on the haemodynamic and stress response to skull-pin placement for craniotomy, Eur J Anaesthesiol 2009
recall · CA-2 · phrased by llm
A systematic review and meta-analysis of 23 randomised trials in 1532 patients examined scalp block for postoperative pain and opioid use after craniotomy. Give the size of the analgesic and opioid-sparing effects, and say how you would present those numbers when arguing for the block on a neurosurgical pathway.
Answer: Scalp block reduced postoperative visual analogue pain scores from 2 through 72 hours, by mean differences of 0.79 to 1.40 points, and reduced opioid requirement by 16.52 morphine milligram equivalents at 24 hours and 15.63 at 48 hours. Overall risk of bias across the trials was low. The honest presentation is that these are modest absolute reductions — around one point of pain and about 16 morphine milligram equivalents — and that is how the authors themselves ask them to be read: the clinical utility of the differences should be interpreted in the context of the modest absolute size, of overall care optimisation, and of the patient population. Note the limits of what you can quote from this paper: it measured pain and opioid consumption, so it will support an argument that the block is a real if small addition to an opioid-sparing pathway, but it did not measure the block's cost, its procedure time or its complication rate, and an argument resting on those has to be sourced elsewhere.
This is the largest randomised evidence base for the block, and the authors themselves ask that the differences be read against the modest absolute size and against the population being treated. Whether a one-point pain reduction and about 16 morphine milligram equivalents matter more in a neurosurgical patient than elsewhere is a judgement this review invites and does not make.
Source claim: Pooling 23 randomised trials with 1532 patients undergoing craniotomy, scalp block reduced postoperative visual analogue pain scores from 2 through 72 hours with mean differences of 0.79 to 1.40, and reduced opioid requirements by 16.52 morphine milligram equivalents at 24 hours and 15.63 morphine milligram equivalents at 48 hours, with overall low risk of bias.
Duda T et al., Systematic Review and Meta-Analysis of Randomized Controlled Trials for Scalp Block in Craniotomy, Neurosurgery 2023
recall · CA-2 · phrased by llm
This meta-analysis found that adding dexmedetomidine to local anaesthetic for scalp nerve blocks in craniotomy patients reduced heart rate by ___ bpm and mean arterial pressure by 8.5 mmHg at pin fixation, and prolonged time to first rescue analgesia by 215 minutes.
Answer: 8.1
This meta-analysis found that adding dexmedetomidine to local anaesthetic for scalp nerve blocks in craniotomy patients reduced heart rate by 8.1 bpm and mean arterial pressure by 8.5 mmHg at pin fixation, and prolonged time to first rescue analgesia by 215 minutes.
The efficacy and safety of dexmedetomidine as an adjuvant to local anaesthetics in scalp nerve blocks in patients undergoing craniotomy: A systematic review and meta-analysis of randomized controlled trials · PMID 41138510
recall · CA-2 · phrased by derived
This randomized trial found that adding dexmedetomidine ___ mcg/kg instead of dexamethasone 8 mg to 0.5% ropivacaine for scalp nerve blocks in awake craniotomy prolongs time to first rescue analgesia to 14 hours and better attenuates the hemodynamic response to skull pin fixation.
Answer: 1
This randomized trial found that adding dexmedetomidine 1 mcg/kg instead of dexamethasone 8 mg to 0.5% ropivacaine for scalp nerve blocks in awake craniotomy prolongs time to first rescue analgesia to 14 hours and better attenuates the hemodynamic response to skull pin fixation.
Comparison of the efficacy of dexmedetomidine and dexamethasone as adjuvants to ropivacaine for scalp nerve block in patients undergoing awake craniotomy: A randomized controlled trial · PMID 41197576
recall · CA-2 · phrased by derived
This review recommends minimizing opioids to facilitate prompt postoperative neurosurgical assessment and found that scalp nerve blocks lower pain and opioid consumption for the first ___ hours while significantly decreasing postoperative nausea and vomiting.
Answer: 48
This review recommends minimizing opioids to facilitate prompt postoperative neurosurgical assessment and found that scalp nerve blocks lower pain and opioid consumption for the first 48 hours while significantly decreasing postoperative nausea and vomiting.
Nerve Blocks for Craniotomy · PMID 38472617
recall · CA-2 · phrased by derived
This randomized trial found that a multimodal protocol including a postoperative bupivacaine scalp block, gabapentin, dexmedetomidine, acetaminophen, and ketorolac significantly reduced VAS pain scores at 1, 2, and ___ hours after elective supratentorial craniotomy compared to IV morphine.
Answer: 4
This randomized trial found that a multimodal protocol including a postoperative bupivacaine scalp block, gabapentin, dexmedetomidine, acetaminophen, and ketorolac significantly reduced VAS pain scores at 1, 2, and 4 hours after elective supratentorial craniotomy compared to IV morphine.
Opioid-sparing multimodal analgesia for post-craniotomy pain: a randomized, double-blind, placebo-controlled trial · PMID 40883667
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.