While the practice of titrating oxygen to resuscitate struggling newborns has led to better outcomes, there is a disagreement within the medical community about what concentration of oxygen should be given to vulnerable preterm babies born before 29 weeks of gestation.
University of Alberta neonatologist Georg Schmölzer said what complicates this knowledge gap is that, until fairly recently, researchers even disagreed on the optimal concentration of oxygen to resuscitate an otherwise healthy full-term baby.
"When I started training in the early 2000s, it was customary that you give 100 per cent oxygen to a baby to get the baby 'pinked up' as fast as possible, because babies come out blue as the womb is a low-oxygen environment."
Though 100 per cent oxygen got full-term babies pink faster, researchers noticed rates of leukemia and mortality were lower when babies were resuscitated with regular air, which contains 21 per cent oxygen.
"They found giving 100 per cent oxygen can actually prevent a baby from starting to breathe at birth and can create apnea for a brief period of time," said Schmölzer, who holds the Heart and Stroke Foundation/University of Alberta Professorship in Neonatal Resuscitation.
In 2010, guidelines for resuscitating full-term babies changed to the use of air only. But what about babies born extremely prematurely?
Schmölzer explained that at the gestational age of 29 weeks or earlier, the lungs are not fully developed and it is common for infants to have problems breathing at birth.
"We started at 100 per cent, but given that we know 100 per cent isn't perfect in term infants, a lot of experts around the world are suggesting maybe we should give less as well," he said.
He noted there are a number of problems associated with having too much oxygen in the system. Once in the body, oxygen atoms split into free radicals, which are thought to play a role in a host of ailments including chronic lung disease and retinopathy of prematurity, a condition caused by abnormal development of blood vessels in the retinas of premature babies that can lead to blindness. The body fights the destruction to cells caused by free radicals using antioxidants, which preterm babies lack. An increase in the oxygen concentration can also lead to damage to the brain.
It turns out, however, using just air to resuscitate preterm babies led to higher mortality.
In an effort to pin down the precise oxygen concentration needed to resuscitate preterm babies, Schmölzer and his international research team received $2.2 million from the Canadian Institutes of Health Research. The researchers will compare outcomes at 18 to 24 months of preterm babies born between 23 and 28 weeks premature who were administered either 30 per cent or 60 per cent oxygen.
"We hope that the 60 per cent oxygen will improve long-term outcomes, including (lower rates of) mortality and cerebral palsy, less babies who have visual issues, less babies who have hearing impairments, less babies who have major developmental delays," said Schmölzer, who also receives funding and support from the Stollery Children's Hospital Foundation through the Women and Children's Health Research Institute.
Overall, the U of A will receive $26 million in CIHR funding for 32 projects as part of the federal funding body's fall project grant round.
CIHR grant recipients from U of A
Barbara Ballermann (medicine and dentistry)
Podocyte remodeling in hypertension and diabetic nephropathy: role of CLIC5A, $745,876
David Bennett, Keith Fenrich, Karim Fouad and Jaynie Yang (rehabilitation medicine)
Targeting pericytes to restore sensorimotor function after spinal cord injury, $1,105,425
David Brindley (medicine and dentistry)
Targeting lysophosphatidate signaling to improve therapeutic outcomes for breast cancer patients, $937,125
Robin Clugston (medicine and dentistry)
Altered vitamin A homeostasis and retinoic acid signaling in the development of congenital diaphragmatic hernia, $569,925
Emmanuelle Cordat (medicine and dentistry)
Physiological and pathophysiological roles of renal intercalated cells, $826,200
Greta Cummings (nursing), Gillian Harvey (arts) and Christy Raymond (nursing)
Contextually appropriate nurse staffing models: a realist review, $313,649
Ratmir Derda (science)
Development of small macrocyclic antibody-like scaffolds for therapeutic inhibition of Nodal, $841,500
Ayman El-Kadi (pharmacy and pharmaceutical sciences)
Role of cytochrome P450 enzymes in pathogenesis of cardiac hypertrophy in different sexes, $738,225
Mark Glover (medicine and dentistry)
Role of BRCT proteins in DNA damage signaling $826,200
Donald Gross (medicine and dentistry)
Using advanced imaging techniques to demonstrate hippocampal subfield pathology and predict surgical outcome in temporal lobe epilepsy, $852,975
James Hammond (medicine and dentistry)
Regulation of SLC43A3 expression and function, and its impact on 6-mercaptopurine cytotoxicity and resistance in the treatment of leukemia, $642,600
Michael Houghton (medicine and dentistry)
Designing a component in prophylactic vaccine to induce broad cross-genotype neutralization against heterogeneous clades of HCV, $761,175
Jesse Jackson (medicine and dentistry)
Dissecting the role of the claustrum in anxiety, $730,575
Dina Kao (medicine and dentistry)
A multicentre, double blind, randomized trial comparing lyophilized fecal filtrate to lyophilized stool in treating recurrent Clostridiodes difficile infection, $1,314,115
Padma Kaul (medicine and dentistry)
Pregnancy complications and long-term risk of cardiovascular disease, $470,475
Kirst King-Jones (science)
Characterization of the transcriptional and post-transcriptional iron regulome, $963,900
Kirst King-Jones (science)
Novel roles for iron regulatory protein 1, $901,170
Todd McMullen (medicine and dentistry)
An immuno-PET-PDGFRa conjugate to identify metastases and predict outcomes for papillary thyroid cancer, $818,550
Margaret McNeely (rehabilitation medicine) and Puneeta Tandon (medicine and dentistry)
HEAL-ME ACE: An interactive eHealth network delivering personalized exercise, physiotherapy and nutrition programming and support to rural and remote breast cancer survivors, $100,000
Marek Michalak (medicine and dentistry)
Molecular mechanisms that promote cardiac cell survival and heart health, $970,785
David Olson (medicine and dentistry)
The role of interleukin-1 beta in preterm birth diagnosis and treatment, $1,067,175
Maria Ospina (medicine and dentistry)
Understanding health and well-being trajectories of Métis children in Alberta, $650,252
Hanna Ostergaard (medicine and dentistry)
Role of the cytoskeletal adaptor protein leupaxin in immune response regulation, $100,000
Gavin Oudit (medicine and dentistry)
Novel interplay between the apelin pathway and neutral endopeptidase in heart disease, $761,175
Georg Schmölzer (medicine and dentistry)
Does the use of higher versus lower oxygen concentration improve neurodevelopmental outcomes at 18-24 months in very low birthweight infants?-The HiLo-Trial, $2,222,325
Lorne Tyrrell (medicine and dentistry)
The critical role of the nuclear pore complex during the life cycle of RNA viruses that replicate in the cytoplasm, $849,150
Michael Weinfeld (medicine and dentistry)
Polynucleotide kinase/phosphatase: its role in DNA strand break repair and a potential therapeutic target to enhance radio- and chemotherapy, $940,950
Eytan Wine (medicine and dentistry)
Microbial causes of ulcerative colitis: looking outside the involved region, $895,050
Stephanie Yanow (public health)
Exploiting a cross-reactive epitope in plasmodium vivax PvDBP to develop a vaccine against falciparum placental malaria, $795,600
Toshifumi Yokota (medicine and dentistry)
Targeting RNA splicing for the treatment of Duchenne muscular dystrophy, $692,325
Roger Zemp (engineering)
Photoacoustic remote sensing virtual histology for tumour margin assessment, $551,542
Douglas Zochodne (medicine and dentistry)
Rewiring diabetic axons: rescue, regrowth and repurposing insulin, $803,250