Low dose sux, subtherapeutic or good idea?

  1. One anesthesia provider suggested using low dose sux for induction (20-40mg) saying "all you need is vocal cord paralysis". While another refused saying "this is dangerous as you increase risk of aspiration on DL secondary to a half-paralyzed diaghragm"?
    I've never used low dose sux, but if someone has, what is your experience is the onset the same, duration the same...etc? any thoughts? thanks
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  2. 11 Comments

  3. by   gotosleep
    Quote from miloisstinky
    One anesthesia provider suggested using low dose sux for induction (20-40mg) saying "all you need is vocal cord paralysis". While another refused saying "this is dangerous as you increase risk of aspiration on DL secondary to a half-paralyzed diaghragm"?
    I've never used low dose sux, but if someone has, what is your experience is the onset the same, duration the same...etc? any thoughts? thanks
    20-40mg is just absurd. what is the point of this? Either you give the drug or you don't. I can imagine the plaintiff's expert having a lot of fun with you after your patient aspirates.
  4. by   JJRN
    According to Mass General, induction ED95 for succs is 0.25mg/kg so in theory a 20-40 mg dose of succs would be adequate...
  5. by   yoga crna
    Years ago, we used the lower doses you mention. Actually, it worked pretty well, except it could be marginal when you need more profound relaxation. I changed to higher doses and would use that now if I intubate with succinylcholine. I would rather use cisatracrium (Nimbex) for elective intubations--have probably done 2 RSI's in the last 20 years, so it is not an isssue in my current practice.

    What I do think is interesting, is that you don't need a large dose of succinylcholine to break up a laryngospasm, 10 mg works well and does not give the patient the side-effects of muscle pain.

    yoga
  6. by   jewelcutt
    According to Larson, the laryngospasm expert, a sub-therapeutic dose of succs can be used to treat a laryngospasm, .1-.2mg/kg. As I was thinking of this question I was remembering the order of muscles relaxing after being given a relaxant. Yoga, have you used these doses on laryngospasms, and have they worked?
  7. by   gotosleep
    Quote from JJRN
    According to Mass General, induction ED95 for succs is 0.25mg/kg so in theory a 20-40 mg dose of succs would be adequate...
    i'm aware of that. there is a reason the RECOMMENDED dose is 1mg-1.5mg/kg for RSI though.
  8. by   mwbeah
    optimal dose of succinylcholine revisited.
    anesthesiology. 99(5):1045-1049, november 2003.
    naguib, mohamed m.b., b.ch., m.sc., f.f.a.r.c.s.i., m.d. *; samarkandi, abdulhamid m.b., b.s., k.s.u.f., f.f.a.r.c.s.i. +; riad, waleed m.b., b.ch., m.sc., a.b., m.d. ++; alharby, saleh w. m.b., b.s., f.r.c.s. (glas) [s]


    abstract:
    background: the authors reappraised the conventional wisdom that the intubating dose of succinylcholine must be 1.0 mg/kg and attempted to define the lower range of succinylcholine doses that provide acceptable intubation conditions in 95% of patients within 60 s.

    methods: this prospective, randomized, double-blind study involved 200 patients. anesthesia was induced with 2 [mu]g/kg fentanyl and 2 mg/kg propofol. after loss of consciousness, patients were randomly allocated to receive 0.3, 0.5, or 1.0 mg/kg succinylcholine or saline (control group). tracheal intubation was performed 60 s later. a blinded investigator performed all laryngoscopies and also graded intubating conditions.

    results: intubating conditions were acceptable (excellent plus good grade combined) in 30%, 92%, 94%, and 98% of patients after 0.0, 0.3, 0.5, and 1.0 mg/kg succinylcholine, respectively. the incidence of acceptable intubating conditions was significantly greater (p < 0.05) in patients receiving succinylcholine compared with those in the control group but was not different among the different succinylcholine dose groups. the calculated doses of succinylcholine (and their 95% confidence intervals) that were required to achieve acceptable intubating conditions in 90% and 95% of patients at 60 s were 0.24 (0.19-0.31) mg/kg and 0.56 (0.43-0.73) mg/kg, respectively. conclusions: the use of 1.0 mg/kg of succinylcholine may be excessive if the goal is to achieve acceptable intubating conditions within 60 s. comparable intubating conditions were achieved after 0.3, 0.5, or 1.0 mg/kg succinylcholine. in a rapid-sequence induction, 95% of patients with normal airway anatomy anesthetized with 2 [mu]g/kg fentanyl and 2 mg/kg propofol should have acceptable intubating conditions at 60 s after 0.56 mg/kg succinylcholine. reducing the dose of succinylcholine should allow a more rapid return of spontaneous respiration and airway reflexes.
  9. by   DreamMatrix
    I've used 40-60 mg of Sux many, many times. Never had a problem doing it.
    Last edit by DreamMatrix on Oct 9, '05
  10. by   DreamMatrix
    Quote from gotosleep
    20-40mg is just absurd. what is the point of this? Either you give the drug or you don't. I can imagine the plaintiff's expert having a lot of fun with you after your patient aspirates.
    I've used 40-60 mg of Sux many, many times. Never had a problem doing it. Absurd! Not at all!! Never use more than 100 mg EVER.
  11. by   louloubell1
    Quote from DreamMatrix
    I've used 40-60 mg of Sux many, many times. Never had a problem doing it. Absurd! Not at all!! Never use more than 100 mg EVER.
    I have heard the max of 100 mg thing from a couple different CRNAs in my clinical rotations, but haven't found that in any literature. Can you tell me what the rationale for 100 mg max is?
    Thanks,
    Lou
  12. by   DreamMatrix
    Quote from RNLou
    I have heard the max of 100 mg thing from a couple different CRNAs in my clinical rotations, but haven't found that in any literature. Can you tell me what the rationale for 100 mg max is?
    Thanks,
    Lou
    It is not a max dose...it is simply all I have ever needed to use...ever...and I've done anesthesia for quite a few years, so if it works then I see no reason to use any more. I guess that is the "art" part of anesthesia that comes with experience.
  13. by   mwbeah
    Quote from rnlou
    i have heard the max of 100 mg thing from a couple different crnas in my clinical rotations, but haven't found that in any literature. can you tell me what the rationale for 100 mg max is?
    thanks,
    lou
    "the average dose required to produce neuromuscular blockade and to facilitate tracheal intubation is 0.6 mg/kg anectine injection given intravenously. the optimum dose will vary among individuals and may be from 0.3 to 1.1 mg/kg for adults. following administration of doses in this range, neuromuscular blockade develops in about 1 minute; maximum blockade may persist for about 2 minutes, after which recovery takes place within 4 to 6 minutes. however, very large doses may result in more prolonged blockade. a 5- to 10-mg test dose may be used to determine the sensitivity of the patient and the individual recovery time"

    fyi dosing variations

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