During filming, Robin Williams and the rest of the cast and crew worked closely with the Make-A-Wish Foundation to fulfill the fantasies of several children who were at the time undergoing cancer treatment. The children appeared with Williams in scenes at the pediatric ward.
When Dean Walcott is walking down the hall, right before he enters the room where Patch is playing with the hospital bed, there is a page that comes over the intercom for Dr. Maslow to dial 214. Dr. Abraham Maslow, noted psychologist, developed the "Hierarchy of Needs" that explains how the personality reacts to environmental factors and needs.
When Patch is bothering his classmates with the anatomical skeleton he makes a joke about the "Donner Party." This is a historical reference to the Donner Party, a group of wagon train pioneers who left for California in 1846 and became stuck in the Sierra Nevada mountain range during the winter after an early November snow fall made the trip through impossible until the spring. When food supplies ran out, some of the group resorted to cannibalism to make it through the winter. Of the original 87 members, only 48 survived and reached California.