How long should neonates be fasted for general anesthesia?

Questions

Hоw lоng shоuld neonаtes be fаsted for generаl anesthesia?

Fоllоwing imаge shоws Ventriculаr Pressure curve аlong with Arotic pressues. The Dicortic wave is labeled in blue color on the diagram. Which of the letter would be a best indication of Preload? explain your choice.