6. Classification of Blockers www.freelivedoctor.com Agent Pharmacological Properties Onset time (min) Duration (min) Elimination Succinylcholine Ultrashort acting; Depolarizing 1-1.5 6-8 Plasma cholinesterase D-tubocurarine Long duration; Competitive 4-6 80-120 Renal and liver Atracurium Intermediate duration; Competitive 2-4 30-40 Plasma cholinesterase Mivacurium Short duration; Competitive 2-4 12-18 Plasma cholinesterase Pancuronium Long duration; Competitive 4-6 4-6 Renal and liver Rocuronium Intermediate duration; competitive 1-2 1-2 Renal and liver
7. Muscle AP Nerve AP Left Leg Muscle Stimulation Right Leg Nerve Stimulation Right Leg Muscle Stimulation Site of Action of d-Tubocurarine www.freelivedoctor.com
10. Comparison of Competitive and Depolarizing Blocking Agents www.freelivedoctor.com Competitive Depolarizing Effect of previous d-tubocurarine Additive Antagonistic Effect of previous decamethonium None/antagonistic May be additive Efect of cholinesterase inhibitors Reverse No antagonism Effect on motor end plate Elevated threshold to Ach; no depolarization Partial, persisting depolarization Initial excitatory effect None Transient fasciculations Effect of KCl or tetatnus on block Transient reversal No antagonism
11. Dual Block by Depolarizing Agents C10: decamethonium; NEO: neostigmine; TC: tubocurarine NEO reversed the blockade by C10. www.freelivedoctor.com
13. Sequence of Paralysis Fingers, orbit (small muscles) limbs Trunk neck Intercostals Diaphragm Recovery in Reverse www.freelivedoctor.com
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16. Systolic BP Systolic BP % Change in Systolic BP with d-Tubocurarine as a Function of Dose and Depth of Anesthesia Increasing Dose of d-tubocurarine Increasing Depth (% Halothane) 0.25% 0.5% 0.75% 6 mg/m 2 12 mg/m 2 18 mg/m 2 www.freelivedoctor.com
17. Influence of Type of Anesthetic on Enhancement of Neuromuscular Blockade By d-Tubocurarine www.freelivedoctor.com
18. HR CO SVR MAP Hemodynamic Effects of d-Tubocurarine and Pancuronium www.freelivedoctor.com
![Neuromuscular Blockers ,[object Object],[object Object],[object Object],[object Object],www.freelivedoctor.com](https://image.slidesharecdn.com/neuromuscular-blockers-100420022059-phpapp01/85/Neuro-muscular-blockers-1-320.jpg)
