She was in the water for 15 minutes

PETER DOCKRILL
19 JUL 2017

Researchers in the US have reported what they believe is a first-of-its-kind reversal of brain damage, after treating a drowned and resuscitated toddler with a combination of oxygen therapies.

The little girl, whose heart didn't beat on her own for 2 hours after drowning, showed deep grey matter injury and cerebral atrophy with grey and white matter loss after the incident, and could no longer speak, walk, or respond to voices – but would uncontrollably squirm around and shake her head.

Amazingly, thanks to a course of oxygen treatments – including hyperbaric oxygen therapy (HBOT) – administered by a team from LSU Health New Orleans and the University of North Dakota, doctors were able to significantly reverse the brain damage experienced by the toddler.

"The startling regrowth of tissue in this case occurred because we were able to intervene early in a growing child, before long-term tissue degeneration," says hyperbaric specialist Paul Harch from the LSU Health New Orleans School of Medicine.

The drowning occurred in February of last year, when two-year-old Eden Carlson slipped through a baby gate while her mother took a shower, then made it past a heavy door, before eventually falling into the family swimming pool.

She was in the water for 15 minutes before being discovered and had experienced cardiac arrest, and while her mother immediately began CPR, Eden wasn't successfully resuscitated for 2 hours, being eventually revived by doctors at Washington Regional Medical Centre in Fayetteville, Arkansas.

After receiving critical care in hospital for 48 days, the little girl was discharged, but due to the extent of her brain injuries and their physical side effects, Harch proposed treatment with oxygen therapies in an attempt to "wake up" Eden's damaged brain.

Hyperbaric oxygen therapy works by administering oxygen to a patient at an ambient pressure higher than atmospheric pressure, through the use of a sealed, pressurised chamber.

By doing this, the amount of oxygen in a patient's blood supply is increased, which can restore normal levels of blood gases and repair damaged tissue.

In this case, Eden wasn't located close enough to a hyperbaric oxygen therapy chamber, so the team began a bridging course of normobaric oxygen treatments – delivered at sea level pressure – at fifty-five days after the drowning.

The treatments, given for 45 minutes twice a day through a nasal cannula, saw Eden recover alertness and reduced her squirming, giving her back increased movement of her arms and hands.

She also regained part of her ability to eat orally, and could speak short sequences – and laugh.
About three weeks later, the researchers moved Eden and family to New Orleans, where she began a round of new treatments in a hyperbaric chamber.

After just 10 sessions, Eden's mother observed that the toddler was back to "near normal, except for gross motor function", and so the little girl began physical therapy in addition to the hyperbaric treatment.

Once 39 hyperbaric sessions were completed, Eden's walking had improved, and her speech level was assessed to be now greater than it was at the time of the drowning. She demonstrated improvements on all neurological abnormality tests, and showed near normal motor function and cognition.

At the conclusion of the treatment, some 162 days after she drowned, MRI scans revealed that Eden still bore a mild residual injury to her brain, but had experienced a near-complete reversal of cortical and white matter atrophy.

The team studying her recovery say that to their knowledge, this kind of reversal is "unreported with any therapy".

And while they don't fully understand the exact breakdown of this amazing revival in Eden's fortunes, it's clear that normobaric and hyperbaric oxygen treatments combined to reduce inflammation and promote brain cell survival.

"Although it's impossible to conclude from this single case if the sequential application of normobaric oxygen then HBOT would be more effective than HBOT alone, in the absence of HBOT therapy, short duration, repetitive normobaric oxygen therapy may be an option until HBOT is available," Harch says.

"Such low-risk medical treatment may have a profound effect on recovery of function in similar patients who are neurologically devastated by drowning."