Lung surfactant is extracted for distribution to hospitals around the world
By Eric Boodman, STAT
LONDON – Few meat processing plants bother with the foamy liquid inside a cow’s lungs. It’s just another fluid in the fluid-filled business of turning an animal into a side of beef. But this foam has near-magical properties for premature babies.
That’s why every Tuesday morning a team from London-based BLES Biochemicals lugs its equipment – hoses, straps, conical tanks, and a valve-laden contraption that looks like it might come in handy for siphoning off the contents of pipes – into an abattoir owned by the Canadian branch of Cargill. The team’s goal is to extract the off-white foam from cows’ lungs so it can later be turned into a product that helps save the lives of babies born prematurely.
Preemies’ lungs, like the rest of them, aren’t quite ready for birth and almost all babies born very early haven’t started producing this foam themselves. It’s called pulmonary surfactant, and without it, their air sacs could collapse, something that happened to then-President John F. Kennedy’s third son, Patrick Bouvier Kennedy, who died in 1963 two days after he was born five and a half weeks early.
In the 1980s, doctors had tried squirting surfactant collected from other creatures into the tiny nostrils and mouths of babies with respiratory distress syndrome while also putting them on ventilators. The transformation was immediate: Newborns went from blue to pink. Their chests filled with air.
The arrival of surfactants in the neonatal intensive care unit in the 1980s was “huge,” said Dr. Paul Jarris, chief medical officer of the March of Dimes. “It was an absolutely major groundbreaking development.” Newborns went from blue to pink, and their chests filled with air.
It also led to a global trade in foam – an odd corner of the pharmaceutical industry whose existence depends on the whims of the livestock business.
Some companies that sell this fluid, called pulmonary surfactant, get it from animal lungs they buy and transport to their labs. BLES gets it directly from the source, embedding within the Cargill production line. BLES then purifies the liquid and ships vials of it across Canada to countries around the world where it is shot into the lungs of struggling premature infants.
The terms are all business – BLES pays Cargill for each lung from which foam is extracted, and its presence has been approved by Canadian food inspectors. But Fraser Taylor and his team envision their Tuesdays in the slaughterhouse as if they were guests. “My main job when I get to the abattoir is to not negatively impact anybody’s day at any time,” explained Taylor. “To not even be noticed would be great.” They set up their equipment while Cargill employees are still trickling in, and they don’t leave until after Cargill’s employees’ day is done. When Cargill breaks for lunch, the BLES workers do too – they try to sit in exactly the same spot in the cafeteria, to be as unobtrusive as possible – and if Cargill does overtime, so does BLES.
The extraction is a four-person job: Once a cow has been dispatched and comes down the line, one of the team members uses a knife to make a vertical slit in the trachea about six or seven inches long. The next person pushes a tube into the opening. It can be a tight fit, “like trying to put your foot in a shoe that’s two sizes too small,” Taylor said.
Once the tube is in place, a third team member manages the machines that do the extraction. One sends about 20 liters of salt water into the lungs. As the water comes flowing back, there’s a head of foam floating on top, a few inches high. That’s what the team is after. A single set of cow lungs usually provides enough surfactant to get two preemies breathing. Once the tube is removed, it’s on to the next cow.
It’s a flurry of movement: tubes being sanitized in scalding hot water, slits being made, tubes inserted and removed, adjustments to the machines. The team has about 28 seconds for each cow, which doesn’t leave much time to think.
Of the 1,500 or so head of cattle that the Cargill facility deals with every day, the BLES team usually manages to do extractions on about 700. If it didn’t break down the foam with solvents and machines, there would be enough of it to fill a good-sized room.
At the end of the day, the small tank that holds the foam – it looks like a silver R2-D2 on wheels – contains enough to make surfactant for about 1,400 babies.
Once back at the BLES facility, the foam is centrifuged then dried down in rotary evaporators. Solvent is added, and then it’s dried down again. Over the course of a few days, the color changes from milky white to a clarified golden brown – like maple syrup, but less viscous. As it gets purified, it turns into a waxy solid, only to be liquefied again. By the time it goes to quality control for double-checking, it is baby-safe.
In the neonatal intensive care unit at the London Health Sciences Center, about a 20-minute drive from the lab where BLES does its purification, a neonatologist pulls back a rocket-ship blanket to show off a baby in the half-light of an isolette. He’d been born a few days before, at just over 26 weeks. He was a deep reddish-pink, and tiny, his chest fluttering with the rapid artificial breaths of a ventilator.
His parents sat by in pajamas, their faces covered in masks. They weren’t thinking about the abattoir an hour and a half drive to the east. Nor could they know about the BLES team and its long road to a partnership with Cargill.
You could still see the traces of the surfactant therapy he had gotten – a colorful tube that lay next to him on the bed. The respiratory therapist had taken a vial from the fridge with what looked like sour milk inside. He’d gently rolled the vial in his hands to warm it, and had then drawn the stuff up into a syringe. He’d attached the syringe to the end of a catheter and nudged the tube down the baby’s throat. Then, counting one Mississippi, two Mississippi, three Mississippi, he’d pushed the foam as far as it would go into the lungs.
This article was adapted from Eric Boodman’s story for STAT, “How an inconspicuous slaughterhouse keeps the world’s premature babies alive.” You can read the full story here: https://www.statnews.com/2018/03/12/cow-surfactant-premature-babies/