In Philadelphia, Penn Medicine had to act fast. Dr. Mitchell Schnall, senior vice president for data and technology, found out about it with a 2 a.m. text.
He says it didn't take long to realize it was a global issue with Crowdstrike, which Penn Medicine uses to prevent cyber attacks.
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"We understood the problem relatively early, but it was a challenging problem to resolve," said Schnall. "The first thing we had to do is early on make some decisions about what are we going to do about elective care?"
Penn Medicine officials opted to cancel elective surgeries and appointments to free up resources for essential surgeries and emergencies.
"We have patients that are in life-and-death situations in ICUs. We have patients in emergency rooms to operate," said Schnall of the need for the hospital to continue operating even during a global computer outage.
Penn Medicine also went to what's known as "downtime procedures."
"(They) include old-fashioned paper documentation," said Schnall. "It included people having to transfer by hand things from one location to another. Imaging was interesting because we could take a CT scan on the scanner but it couldn't go anywhere else, so we had to take the radiologist to the CT scanner to be able to read the images off the scanner."
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Schnall says Penn Medicine is still working through rescheduling the last of the appointments and surgeries that had to be canceled on Friday, but staff members have gotten the majority of them rescheduled.
In a new blog post, Crowdstrike blames the system failure on a bug in a program that was supposed to catch software issues before updates.
"Because of the way Crowdstrike gets into all these computers, we had to touch each computer individually to bring it up," he said, noting that it took a group effort to keep the hospital up and running for the public during the outage.
"I would say (it was) a heroic effort by all of our staff in order to pull something like that off," he said.
As Penn Medicine officials continue to go over what worked, they'll also continue to discuss Crowdstrike and whether the hospital will keep using it in the future.