Medical surge takes place in a condition when the numbers of patients increase more than the capacity of the hospital infrastructure and resources. In such events, the medical surge helps in delivering more than its capacity.
Medical surge can be explained as the ability to provide proper medical evaluation and care during events such as emergencies that exceed the limits of the normal medical infrastructure of an affected.
The reason her grandfather might understand her father better than hers could be because it's his son. Her grandfather raised her father. Which could effect their communication.