Earnings season has revealed surprises, excitement, and disappointment through the past few weeks. Many of health care's biggest names still have yet to report quarterly data, but a number of the sector's top companies have done so -- and have revealed some key storylines to watch.

From Abbott Labs' (NYSE:ABT) thriving nutritionals division to intensifying worries around a big robotic surgical maker, Motley Fool contributor Dan Carroll takes you through three of the top earnings reports from the health-care sector so far and reveals what you'll need to look out for from these companies going forward.