Central Respiratary Depression Produced by Myoneural Blocking Agents

The occurrence of prolonged apneas following the anesthetic use of myoneural blocking agents has been of sufficient magnitude to warrant a substantial number of case reports in the literature.* Suggestion of central respiratory depression by these drugs has been made in clinical observations³ and in laboratory investigation,† in spite of the now classic report of Scott Smith⁶ discounting the possibility of central effects of curare, and in spite of the theoretical postulate proposed by Riker,⁷ that quaternary compounds with "onium" charges are of such a critical molecular size that they cannot penetrate the cell barriers of the central nervous system.

Over a period of 36 months, we observed in a series of approximately 3800 patients who received some form of myoneural blocking agent 13 patients whose clinical picture strongly suggested the presence of central respiratory depression. An attempt has been made to carefully evaluate these cases to