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O C T O B E R 2 0 1 5 | O U T P A T I E N TS U R G E R Y. N E T
The reality: The consensus of data suggests that we should be reversing
all patients who are dosed with non-depolarizing muscle relaxant. TOF
ratios of less than 0.9 are associated with post-op residual paralysis
complications. But in a meta-analysis, Naguib, et al., (osmag.net/MtkZ6K)
discovered providers' estimates of the rate of residual paralysis based
on a TOF ratio of less than 0.9 was 34.8%, meaning that 65.2% were at
risk for complications had they been extubated.
Another study (osmag.net/nQ5HGk) found that only 37% of anesthesia
providers could detect fade visually, and only 57% could detect it manu-
ally. Clearly, TOF assessments are unreliable, which suggests that resid-
ual blockade is probably a common cause of respiratory difficulties in
the PACU. The only accurate way to determine 0.9 or higher TOF ratio
is with objective EMG, MMG or acceleromyography (AMG), but some
patients above 0.9 will still display residual paralysis (osmag.net/VTjm2K).
Many believe that if a case goes a certain number of hours, there's no
reason to reverse. But the available data doesn't support this assump-
tion either. Caldwell, et al., (osmag.net/Jx9VZr) assessed the degree of
neuromuscular blockade (NMBD) for up to 4 hours after a single dose
of vecuronium (0.1 mg/kg). The TOF ratio was less than 0.75 in
• 4 of 20 patients at 2 hours,
• 3 of 10 patients at 3 hours, and
• 1 of 20 patients at 4 hours.
A large clinical study
(osmag.net/EWqpE6) examined the inci-
dence of residual paralysis after a single
intubating dose of an intermediate-acting
NMBD and no reversal. Among patients
arriving in the PACU, TOF ratios of 0.7
and 0.9 were observed in 16% and 45%, respectively. In patients tested 2
hours after the NMBD administration, TOF ratios of 0.7 and 0.9 were
z DON'T TEST Even a tiny
dose of cephalosporins
could bring on anaphylaxis.
Mike
MacKinnon,
CRNA