Questions · Local Anesthetic Systemic Toxicity
7 questions, 0 approved. Approve them one at a time — a quiz shows nothing you have not.
Recall — derived from a kept point
Forty minutes after an uneventful interscalene block with ropivacaine, a patient becomes progressively hypotensive and bradycardic on the ward. There were no neurologic symptoms at any point. Your colleague says this cannot be LAST because it is too late and there was no seizure. How do you answer, using the published case series?
Answer: Each feature on its own is within the reported spectrum. In the 1979-2009 review of 93 cases, roughly 40% did not follow the classic picture: symptoms were either substantially delayed after injection, or consisted only of cardiovascular compromise with no CNS toxicity. So neither the delay nor the absence of a seizure is evidence against LAST, and the LAST protocol including lipid emulsion stays on the table.
Timing and the absence of seizure do not exclude LAST. Anchoring on the classic sequence is the specific error this case series was written to correct.
Source claim: In the remainder of 93 reviewed local anaesthetic systemic toxicity cases, symptoms were substantially delayed after injection of local anaesthetic, or involved only signs of cardiovascular compromise with no evidence of central nervous system toxicity.
Di Gregorio et al., Clinical presentation of local anesthetic systemic toxicity: a review of published cases 1979-2009, Reg Anesth Pain Med 2010
recall · CA-2 · phrased by llm
What is the main methodological limitation of the 1979-2009 LAST case review, and what does that mean for how you use its numbers when teaching?
Answer: It is a retrospective review of published case reports, so it cannot establish incidence, outcomes, or the comparative efficacy of any treatment. It can only characterise the clinical spectrum of reported cases. The authors themselves argue this makes the case for a prospective registry. So the 60/40 split is a statement about what LAST can look like, not about how often LAST happens or what works.
Publication bias runs through every number in a case-report series. Use it to widen your differential, never to quote a rate.
Source claim: The authors state that information gained from retrospective case review cannot establish incidence, outcomes, or comparative efficacies of treatment for local anaesthetic systemic toxicity.
Di Gregorio et al., Clinical presentation of local anesthetic systemic toxicity: a review of published cases 1979-2009, Reg Anesth Pain Med 2010
recall · CA-3 · phrased by llm
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.