2. www.freelivedoctor.com

3. www.freelivedoctor.com

4. D-tubocurarine pancuronium Vecuronium Decamethonium Succinylcholine Depolarizing Blockers Competitive Blockers www.freelivedoctor.com

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

8. G: gallamine; TC: tubocurarine; NEO: neostigmine; S: succinylcholine. Non-depolarizing Block www.freelivedoctor.com

9. Depolarizing Block C10: decamethonium TC: tubocurarine NEO: neostigmine S: succinylcholine 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

12. Depolarizing Blocker Competitive Blockade Competitive Blocker Noncompetitive Blockade (desensitization) (electrogenic Na pump) (direct channel block) Changing Nature of Neuromuscular Blockade www.freelivedoctor.com

13. Sequence of Paralysis Fingers, orbit (small muscles) limbs Trunk neck Intercostals Diaphragm Recovery in Reverse www.freelivedoctor.com

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

19. www.freelivedoctor.com