Office brought to halt from power failure and thought I was prepared

Today in the operating room, my laptop stopped communicating with my Electronic Medical Record. There I was without access to my patient records to enter a chart note for the surgery I just performed and review my office notes for the next patient. After restarting the EMR program and still not able to find the server, I realized that my server is down. No answer when I called the office because the phones were off-line, but my Office Manager sends me a text message: "Do you have a power failure there too?"

Despite having installed Uninterruptible Power Supplies on each workstation and my servers, all systems failed. The servers have an APC UPS attached to 4 additional battery packs externally that take up more room than the two main servers. They are designed to last for more than 24 hours. My Office Manager had just a few minutes of power on an APC UPS that is rated as lasting for 95 minutes. Although I regularly replace the batteries in the UPSs, clearly some key ones were past their prime.

The hospital operating room was spared because of back-up generators, but no such luck for the medical building next door in which I practice. All systems were on hold therefore in a busy medical practice. Although I was able to continue performing surgery in the operating room, my office team could not perform the visual fields, nerve scans, and pre-operative tests that keep them busy full time, even when I'm away.

What went wrong and how will I prevent this from happening again? Has anyone else had a similar experience? Do you have stringent measures in place to be able to keep your practice running in the event of a power failure?