My healthcare organization uses Break The Glass with our EMR. I work on the IT side of things so I'm not sure how it applies to the clinicians, but for us it is setup so that if we access any patient record we are required to Break The Glass. In doing so we are forced to enter a comment as to why we need access to the record.
It's a good feature - with the introduction of the HITECH act, and of course with HIPAA, it is important to document why you went into a patient's chart.
As a patient, you have the right to request the names of all of the employees who accessed your medical record and you also have the right to know why they needed to see your chart. By forcing the Break the Glass feature, we as employees are forced to create this documentation. If we didn't have this documentation and a lawsuit was brought against my organization, the individuals who accessed the chart could be held liable if they cannot produce sufficient reason for entering the chart.
So in short, no it is not required, but it is an excellent way to mitigate risk - not only for your organization but for the individuals who can be held liable by HITECH and HIPAA.