Eitan Halley and his friends were looking forward to the Nova Festival last fall, in part because the tickets were affordable.

“We were all looking for jobs, so we didn’t really have a bunch of money,” said Halley, 28. “The second the Nova tickets came out, they were really cheap. We all liked going to parties, and it seemed like a perfect thing to do right before the [school] year started.”

Halley and his friends didn’t know the exact location of the festival ahead of time — part of its mystique — but they planned to drive south to Be’er Shiva, a kibbutz in the general area, a few days early to get supplies. 

“I remember driving and looking out the window and seeing Gaza and just thinking about my time in the army, and how I used to just guard a couple of kilometers away from where I was at the moment,” Halley said. “You grow up in Israel and you feel, in a way, very safe. Even though every year or two you hear sirens and you see rockets exploding over your head, you feel like you have a very stable army and government. And then this kind of thing happens.”

When the Nova Festival location was announced, the group was excited. They went to the site, set up their tents, and started enjoying themselves. There were trance DJs playing, and lots of people drinking, dancing and doing drugs. People stayed up all night, with the party set to crescendo at sunrise.

But the dancing and fun gave way quickly to violence and fear.

On the morning of Oct. 7, Hamas militants broke through the border fence of Gaza at 60 different locations. Israel says some 1,200 people were murdered and more than 251 taken hostage in the Hamas assault, according to Israel.

The attack would trigger an Israeli military response that has caused a humanitarian catastrophe in Gaza that has killed more than 41,000 Palestinians so far, according to the Health Ministry in the Hamas-run enclave. Israeli airstrikes in Gaza are still ongoing.

The first sign people at the Nova Festival had that something was wrong were lights from a barrage of rocket fire.

“I look up and I see the largest — the most rockets I’ve ever seen in my life. And I want to remind you guys, I was on the border of Gaza in other wars, so I’ve seen rockets going over my head, but I’ve never seen it at this volume,” Halley said

The group ran back to their car and began driving towards the festival entrance they had used to come in. They soon got stuck in bumper-to-bumper traffic.

“There was nowhere to move. Everyone was panicking. Rockets were exploding over our heads. We didn’t understand if we’re safe or we’re not safe, we just knew we had to get out of there. And all of a sudden some guy screams to us: ‘There’s another entrance over there.’ So we, the second he said that, we turn around our car and we start driving the other way.”

The group made it to the main road and turned right to return to Be’er Shiva, where they had been staying the last couple days. Many others turned left, toward Tel Aviv.

“All the people that took a left hit the terrorists, and a lot of them didn’t make it out,” Halley said.

The group drove for a few minutes, with rockets whizzing overhead, until they passed a small, roadside shelter. A makeshift structure to protect members of the public who might be caught driving during rocket attacks, it didn’t have a door that closed, just a wall that blocked the entrance from flying debris.

The group pulled over and ran inside to find the shelter already crowded. People continued to squeeze in, including Aner Shapira and Hersh Goldberg-Polin, until a final group of three entered and said they had fled terrorists shooting at their car.

“And at that point, my heart jumped a beat, and I realized that something bad is about to happen,” Halley said. “I remember a few seconds after that happened, we heard cars pull up, a group of people jump out screaming in Arabic, and they started firing at the entrance.”

Halley said everyone in the shelter was trying to call for help — phoning the police, the army — but no matter who they spoke with, they couldn’t get anyone to come to their rescue.

“I’m talking to them, and telling them they’re shooting at us and they’re going to try to kidnap us or kill us, and we’re not getting any reactions,” Halley said.

Then his phone was blasted out of his hand, and he realized the terrorists were throwing grenades into the shelter.

Shapira, who had entered earlier with Goldberg-Polin, immediately jumped into action, picking the live grenades up off the floor and throwing them back out through the shelter entrance.

“He was focused. He understood that he had a mission and he wasn’t willing to do anything else but stay there. He wasn’t looking to hide or to get away or anything. All he was looking for was to fight, to stay alive,” Halley said.

The grenades kept coming. Shapira caught and threw back around eight until, “at one point, there was a really big explosion, and I flew back. Someone flew on me, and when I finally got up, I remember Aner wasn’t standing anymore. He wasn’t with us. Hersh lost his hand up to, I think, right under his elbow,” Halley said.

The attackers threw more grenades, and Halley says he took up the job of throwing them back until they threw in two at once, and one of them exploded. He was knocked unconscious, eventually waking up to see a masked attacker walking over him inside the shelter, carrying an AK-47 and wearing a bandana with the symbol of Hamas.

“I remember you could see his mouth through the mask. He had a little opening and he was smiling, like it was a game that they won, and I was able to keep my eyes open for a second before I passed back out,” Halley said.

The attackers started taking hostages, including Goldberg-Polin, an Israeli-American who was among six hostages killed in September shortly before Israeli forces found them. Goldberg-Polin’s body was found in a tunnel beneath the southern Gaza city of Rafah.

In the shelter, Halley had survived the grenade blast.

“They checked if I was still alive. I don’t know how I remember this because I was out. I was 100% out. I remember I was trying to open my eyes to see what was happening and I just couldn’t, and they just passed me over,” he said.

The attackers sprayed the remaining bodies with bullets, and when Halley woke up, they’d left the shelter.

“I realized that I was sitting in a pile of bodies, and I think we were seven survivors. There were another two or three people that were critically injured. They were trying to be as quiet as possible, because they knew that if they made noise, the terrorists might just walk in and throw another grenade and we wouldn’t be able to do anything. And this haunts me till this day,” Halley said. “They couldn’t be quiet anymore, and they started screaming, because they had gun bullet wounds or shrapnel from the grenades… At some point, they just stopped screaming, and I’m almost sure that they passed away at that moment or they passed away a little bit after that, and from that moment on, we were there for another six hours.”

Halley and the others were eventually found by the father of a festival-goer who’d gotten a frantic phone call from his son from inside the shelter. Upon receiving the call, he grabbed a pistol and drove to the scene.

He managed to call in some army support, and Halley was eventually put into a jeep and driven toward Be’er Shiva.

“I remember seeing on the side of the road — I don’t even know how many, but so many cars just, that looked shot up. A lot of the cars had passengers in it that you could see that they were dead,” Halley said.

Of the more than 3,000 people who went to the Nova Music Festival, 364 were murdered and 44 others were taken as hostages back into Gaza. Hundreds more were wounded, and thousands are still receiving psychological counseling. Some have taken their own lives.

Halley is among the survivors left with both physical and psychological scars.

“I can find myself crying in the middle of the day for no reason,” he said. “It’s very, very tough.”

“I still have headaches from the explosions and from passing out, I think. Dizziness, nausea, I lose my balance, I think, because of my eardrums. My hearing was damaged. Obviously, sleeping is all of a sudden a lot tougher,” he said. “I still do have shrapnel  in most of my body. I can still feel, at times, my skin burning.”

Halley said he tries to avoid things that trigger memories about the attack.

“I haven’t really listened to trance music ever since the 7th of October, and I’m not really willing to listen to it today either,” he said. “One day, I hope that I will be able to go back to parties and dance again and enjoy myself the way I used to.”

Halley is one of several festival-goers who told their stories of survival in “We Will Dance Again,” a See It Now Studios documentary. Stream it now on Paramount+.

Oakland, California — The patient was in his 60s, an African American man with emphysema. The oximeter placed on his fingertip registered well above the 88% blood oxygen saturation level that signals an urgent risk of organ failure and death.

Yet his doctor, Noha Aboelata, believed the patient was sicker than the device showed. So she sent him for a lab test, which confirmed her suspicion that he needed supplemental oxygen at home.

Months later, in December 2020, Aboelata thought back to her patient as she read a New England Journal of Medicine article showing that pulse oximeters were three times as likely to miss dangerously low blood oxygen levels in Black patients as in white ones. At a time when Black Americans were dying of COVID at high rates and hospitals struggled to find beds and oxygen for those needing them, the finding exposed one of the most blatant examples of institutional racism in American health care.

“I was like, ‘Were there other patients I missed?” said Aboelata, a family physician and the CEO of Oakland-based Roots Community Health. As she shared the article with colleagues, “there was so much anger and frustration because we had every reason to believe we could rely on this device, and it was systematically not working in the population that we served.”

State attorneys general and U.S. senators have pressed the FDA to take steps to eliminate pulse oximetry’s racial bias, which has caused delays in treatment and worse health outcomes, and more recently has raised concern about the reliability of hospital AI tools to draw on reams of data from the devices.

Aboelata’s clinic has sued producers and stores that sell oximeters, demanding they pull the devices or add safety warnings to the labels. Many of her patients rely on home oxygen, which requires accurate readings for Medicare to cover.

But getting rid of the devices, central to care for heart and lung diseases, sleep apnea and other conditions, isn’t an option.

Since the 1990s, the convenient fingertip clamps have come to stand in for many uses of arterial blood gas readings, which are the gold standard for determining oxygen levels but dangerous if not done carefully. Makers of oximeters will sell around $3 billion of them this year because they are used in nearly every hospital, clinic and long-term care facility. During the pandemic, hundreds of thousands of Americans bought them for home use.

One of them was Walter Wilson, a 70-year-old businessman in San Jose, California, who has had two kidney transplants since 2000. Wilson contracted covid last December but delayed visiting a doctor because his home pulse oximetry readings were in the normal range.

“I’m a dark-complected Black guy. I was very sick. Had the oximeter picked that up I would have gotten to the hospital sooner,” he said.

Wilson ended up back on dialysis after several years of good health. Now he’s looking to join a class action lawsuit against the device manufacturers.

“They’ve known for years that people with darker skin get bad readings,” he said, “but they tested them on healthy white people.”

After years of little action on the issue, the FDA in 2021 sent a safety warning to doctors about oximeters. It has also funded research to improve the devices and promised to issue new guidelines for how to make them.

But as the FDA polishes draft guidelines it had hoped to publish by Oct. 1, clinicians and scientists are unsure what to expect. The agency has indicated it will recommend that manufacturers test new oximeters on more people, including a large percentage with dark-pigmented skin.

Because of industry pushback, however, the guidance isn’t expected to ask device makers to test oximeters under real-world conditions, said Michael Lipnick, a University of California-San Francisco anesthesiologist and researcher.

Hospitalized people are often dehydrated, with restricted blood flow to their extremities. This condition, known as low perfusion — essentially, poor circulation — is particularly common with cardiovascular disease, which is more prevalent in Black patients.

Pigmentation and poor perfusion “work together to degrade pulse oximetry performance,” said Philip Bickler, who directs the Hypoxia Research Lab at UCSF. “During covid, Black patients showed up sicker because of all the barriers those patients face in accessing health care. They’re showing up on death’s door, and their perfusion is lower.”

The FDA guidance isn’t expected to require manufacturers to measure how well their devices perform in patients with poor perfusion. All this means that the FDA’s efforts could lead to devices that work in healthy dark-skinned adults but do “not fix the problem,” said Hugh Cassiere, who chairs a panel for the FDA’s Medical Devices Advisory Committee, at its February meeting.

A history of inaction

Although some recent industry-sponsored studies have shown that certain devices work across skin tones, research dating to the 1980s has found discrepancies in pulse oximetry. In 2005, Bickler and other scientists at the Hypoxia Lab published evidence that three leading devices consistently failed to detect hypoxemia in darkly pigmented patients — especially those who were severely oxygen-depleted. Noting that these readings could be crucial to directing treatment, the authors called for oximeters to carry warnings.

The FDA’s response was modest. Its regulatory pathway for pulse oximeters clears them for sale as long as they show “substantial equivalence” to devices already on the market. In a 2007 draft guidance document, the FDA suggested that tests of new oximeters could “include a sufficient number of subjects with dark skin pigmentation, e.g., 30%.” However, the final guidance, issued in 2013, recommended “at least 2 darkly pigmented subjects or 15% of your subject pool, whichever is larger.” The studies were required to have only 10 subjects. And the agency did not define “dark-pigmented.”

Testing the devices involves fitting patients with masks that control the gases they breathe, while simultaneously taking pulse oximetry readings and samples of arterial blood that are fed into a highly accurate measuring device, invented by the Hypoxia Lab’s late founder, John Severinghaus.

Bickler, who evinces the bemused skepticism of a seasoned car mechanic when discussing the scores of devices his lab has tested, said “you can’t always trust what the manufacturers say.”

Their data, he said, ranges from “completely inaccurate” to “obtained under absolutely ideal conditions, nothing like a real-world performance.”

During the pandemic, a medical charity approached the lab about donating thousands of oximeters to poor countries. The oximeters it had chosen “weren’t very good,” he said. After that, the lab set up its own ratings page, a kind of Consumer Reports for pulse oximeters.

According to its tests, some expensive devices don’t work; a few of the $35 gadgets are more effective than competitors costing $350. Over a third of the marketed devices the lab has tested don’t meet current FDA standards, according to the site.

To investigate whether real-world tests of oximeters are feasible, the FDA funded a UCSF study that has recruited about 200 intensive care unit patients. The data from the study is being prepared to undergo peer review for publication, Bickler said.

He said the lab did not warm the hands of patients in the study, which is the customary practice of manufacturers when they test their devices. Warming assures better circulation in the finger the device is attached to.

“It affects the signal-to-noise ratio,” Bickler said. “Remember when car radios had AM stations, and you’d get a lot of static? That’s what poor perfusion does — it causes noise, or static that can obscure a clear signal from the device.”

Hypoxia Lab scientists — and doctors in the real world — don’t warm patients’ hands. But “the industry people can’t agree on how to handle it,” he said.

Masimo, a company that says it has the most accurate pulse oximeters on the market, would happily comply with any FDA guidance, Daniel Cantillon, Masimo’s chief medical officer, said in an interview.

How much to fix the problem?

The very best devices, according to the Hypoxia Lab, cost $6,000 or more. That points to another problem.

With better accuracy, “you are going to reduce patient access to devices for a large proportion of the world that simply can’t afford them,” Lipnick said.

Even if the FDA can’t please everyone, its anticipated call for more people with darker skin in oximetry tests will “assure there’s real diversity in the development and testing of those devices before they come to market,” Lipnick said. “That bar has been too low for decades.”

It is difficult to assess harm to individuals from faulty oximeter readings, because these errors are often one factor in a chain of events. But studies at Johns Hopkins University and elsewhere indicated that patients whose oxygen depletion wasn’t noticed — possibly thousands of them — had delayed treatment and worse outcomes.

Already, Aboelata said, a few manufacturers — Zewa Medical Technology, Veridian Healthcare and Gurin Products — have responded to the Roots Community Health lawsuit by including warnings about their devices’ limitations.

There’s not much she and other clinicians can do in daily practice, she said, other than establish a baseline reading with each new patient and be on the lookout for notable drops. Hospitals have other tools to check oxygen levels, but correct readings are critical for outpatient care, she said. In 2022, Connecticut enacted a law banning insurers from denying home oxygen or other services based solely on pulse oximetry readings.

But “adapting around the crappy device isn’t the solution,” said Theodore Iwashyna, the Johns Hopkins Bloomberg School of Public Health professor who co-authored the New England Journal of Medicine article. “A less crappy device is the solution.”

This article was produced by KFF Health News, a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF — the independent source for health policy research, polling and journalism. KFF Health News is the publisher of California Healthline, an editorially independent service of the California Health Care Foundation.