Two competing ideas here. On the one hand, a small number of patients given rocuronium will have prolonged blockade, so you need to reverse all patients to make sure you catch the ones with minimal residual blockade. However, the second paper shows that patients whose rocuronium has nearly worn off can actually be paradoxically *weakened* by a dose of reversal. So you're between a rock and a hard place.
Reversal of residual neuromuscular block with neostigmine at one to four hours after a single intubating dose of vecuronium.
Caldwell JE. Anesth Analg. 1995.
The purpose of this study was to measure the degree of residual neuromuscular block at different times after a single dose of vecuronium, and to evaluate the effectiveness of two different doses of neostigmine in antagonizing this residual block. Train-of-four (TOF) ratios were examined for up to 4 h after a single dose of vecuronium, 0.1 mg/kg, in 60 patients during nitrous oxide/isoflurane/fentanyl anesthesia. The effect of neostigmine, 40 micrograms/kg, was studied at 1,2,3, or 4 h. The effect of neostigmine, 20 micrograms/kg, was studied at 2 or 4 h after the vecuronium. Before neostigmine administration, the TOF ratio was less than 0.75 in 17 patients (including one patient at 4 h). Neostigmine produced an increase in TOF ratio in 52 patients and a decrease in 8. The TOF ratio decreased after neostigmine only, at 2,3, or 4 h after vecuronium, when the TOF ratio was > or = 0.9 and when neostigmine 40 micrograms/kg was administered. One patient, at 1 h, had a TOF ratio of 0.00 and this did not reach 0.75 until 57 min after neostigmine, 40 micrograms/kg. There was a high incidence (50%) of adverse cardiovascular effects after both doses of neostigmine. In making the decision as to whether neostigmine should be administered, the risk to the patient of residual neuromuscular block must be balanced against the adverse cardiovascular effects of the neostigmine.
PMID 7762847
http://www.ncbi.nlm.nih.gov/pubmed/7762847
Neostigmine/glycopyrrolate administered after recovery from neuromuscular block increases upper airway collapsibility by decreasing genioglossus muscle activity in response to negative pharyngeal pressure.
Herbstreit F, et al. Anesthesiology. 2010.
BACKGROUND: Reversal of residual neuromuscular blockade by acetylcholinesterase inhibitors (e.g., neostigmine) improves respiratory function. However, neostigmine may also impair muscle strength. We hypothesized that neostigmine administered after recovery of the train-of-four (TOF) ratio impairs upper airway integrity and genioglossus muscle function.
METHODS: We measured, in 10 healthy male volunteers, epiglottic and nasal mask pressures, genioglossus electromyogram, air flow, respiratory timing, and changes in lung volume before, during (TOF ratio: 0.5), and after recovery of the TOF ratio to unity, and after administration of neostigmine 0.03 mg/kg IV (with glycopyrrolate 0.0075 mg/kg). Upper airway critical closing pressure (Pcrit) was calculated from flow-limited breaths during random pharyngeal negative pressure challenges.
RESULTS: Pcrit increased significantly after administration of neostigmine/glycopyrrolate compared with both TOF recovery (mean ± SD, by 27 ± 21%; P = 0.02) and baseline (by 38 ± 17%; P = 0.002). In parallel, phasic genioglossus activity evoked by negative pharyngeal pressure decreased (by 37 ± 29%, P = 0.005) compared with recovery, almost to a level observed at a TOF ratio of 0.5. Lung volume, respiratory timing, tidal volume, and minute ventilation remained unchanged after neostigmine/glycopyrrolate injection.
CONCLUSION: Neostigmine/glycopyrrolate, when administered after recovery from neuromuscular block, increases upper airway collapsibility and impairs genioglossus muscle activation in response to negative pharyngeal pressure. Reversal with acetylcholinesterase inhibitors may be undesirable in the absence of neuromuscular blockade.
PMID 20980910
http://www.ncbi.nlm.nih.gov/pubmed/20980910
--> Reversal of residual neuromuscular block with neostigmine at one to four hours after a single intubating dose of vecuronium.
Caldwell JE. Anesth Analg. 1995.
The purpose of this study was to measure the degree of residual neuromuscular block at different times after a single dose of vecuronium, and to evaluate the effectiveness of two different doses of neostigmine in antagonizing this residual block. Train-of-four (TOF) ratios were examined for up to 4 h after a single dose of vecuronium, 0.1 mg/kg, in 60 patients during nitrous oxide/isoflurane/fentanyl anesthesia. The effect of neostigmine, 40 micrograms/kg, was studied at 1,2,3, or 4 h. The effect of neostigmine, 20 micrograms/kg, was studied at 2 or 4 h after the vecuronium. Before neostigmine administration, the TOF ratio was less than 0.75 in 17 patients (including one patient at 4 h). Neostigmine produced an increase in TOF ratio in 52 patients and a decrease in 8. The TOF ratio decreased after neostigmine only, at 2,3, or 4 h after vecuronium, when the TOF ratio was > or = 0.9 and when neostigmine 40 micrograms/kg was administered. One patient, at 1 h, had a TOF ratio of 0.00 and this did not reach 0.75 until 57 min after neostigmine, 40 micrograms/kg. There was a high incidence (50%) of adverse cardiovascular effects after both doses of neostigmine. In making the decision as to whether neostigmine should be administered, the risk to the patient of residual neuromuscular block must be balanced against the adverse cardiovascular effects of the neostigmine.
PMID 7762847
http://www.ncbi.nlm.nih.gov/pubmed/7762847
Neostigmine/glycopyrrolate administered after recovery from neuromuscular block increases upper airway collapsibility by decreasing genioglossus muscle activity in response to negative pharyngeal pressure.
Herbstreit F, et al. Anesthesiology. 2010.
BACKGROUND: Reversal of residual neuromuscular blockade by acetylcholinesterase inhibitors (e.g., neostigmine) improves respiratory function. However, neostigmine may also impair muscle strength. We hypothesized that neostigmine administered after recovery of the train-of-four (TOF) ratio impairs upper airway integrity and genioglossus muscle function.
METHODS: We measured, in 10 healthy male volunteers, epiglottic and nasal mask pressures, genioglossus electromyogram, air flow, respiratory timing, and changes in lung volume before, during (TOF ratio: 0.5), and after recovery of the TOF ratio to unity, and after administration of neostigmine 0.03 mg/kg IV (with glycopyrrolate 0.0075 mg/kg). Upper airway critical closing pressure (Pcrit) was calculated from flow-limited breaths during random pharyngeal negative pressure challenges.
RESULTS: Pcrit increased significantly after administration of neostigmine/glycopyrrolate compared with both TOF recovery (mean ± SD, by 27 ± 21%; P = 0.02) and baseline (by 38 ± 17%; P = 0.002). In parallel, phasic genioglossus activity evoked by negative pharyngeal pressure decreased (by 37 ± 29%, P = 0.005) compared with recovery, almost to a level observed at a TOF ratio of 0.5. Lung volume, respiratory timing, tidal volume, and minute ventilation remained unchanged after neostigmine/glycopyrrolate injection.
CONCLUSION: Neostigmine/glycopyrrolate, when administered after recovery from neuromuscular block, increases upper airway collapsibility and impairs genioglossus muscle activation in response to negative pharyngeal pressure. Reversal with acetylcholinesterase inhibitors may be undesirable in the absence of neuromuscular blockade.
PMID 20980910
http://www.ncbi.nlm.nih.gov/pubmed/20980910
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