Post cardiac surgery delirium symptoms are worsened by:

- Anticholinergics blocks the actions of ACh on autonomic receptors and in the CNS exeed through muscarinic receptors. Atropine has an overall CNS stimulant action. At low doses these effects are not appreciable, it only produces peripheral effects because of restricted entry into the brain. High doses causes coical excitation, restlessness, disorientation, hallucinations and delirium can occur which is followed by respiratory depression and coma.