Hypoxic Ischemic Encephalopathy Lawyers
A brain injury caused by oxygen loss can change a family's life in minutes. When HIE follows a preventable medical error - at birth, in the operating room, or in the emergency department - families across Canada turn to Diamond and Diamond.
When the brain is starved of oxygen, every minute counts
Hypoxic ischemic encephalopathy - HIE for short - is a brain injury caused by reduced oxygen and blood flow to the brain. The damage can affect a newborn during labour and delivery, or an adult during a cardiac arrest, anaesthesia complication, surgical emergency, or other acute event.
HIE is graded by severity, from mild cases that resolve within days to severe cases that result in lasting cognitive disability, cerebral palsy, seizure disorders, or death. What survivors and their families share is a long, costly recovery and a hard question: could this have been prevented?
When the answer points to a missed warning sign, a delayed intervention, or a failure to meet the standard of care, Canadian families have legal options. Diamond and Diamond Lawyers have experience handling HIE claims for newborns and adults across Toronto, Halifax, Calgary, and throughout Alberta.
Get Your Free Case Evaluation
HIE affects newborns and adults differently
The mechanism - oxygen deprivation followed by reperfusion injury - is similar across ages, but the causes, treatment, and long-term consequences look very different in babies versus adults.
HIE in Newborns
Most often called neonatal HIE or perinatal asphyxia, this form of brain injury happens before, during, or shortly after birth - usually because the baby's oxygen supply was interrupted during labour and delivery. It is one of the leading causes of cerebral palsy and long-term neurological disability in children.
Severity is graded using the Sarnat staging score, which guides treatment and offers a window into prognosis. Therapeutic hypothermia (cooling) within the first six hours of life can meaningfully reduce the damage in moderate and severe cases.
HIE in Adults
In adults, HIE most often follows an acute event that briefly cuts off oxygen and blood flow to the brain - cardiac arrest, respiratory failure, severe blood loss, an overdose, or an anaesthesia emergency. Studies show cardiovascular causes account for roughly a third of adult HIE cases, with overdose a distant second.
The clinical picture ranges from brief confusion through to coma. Targeted temperature management, early CPR, and rapid defibrillation are the difference between recovery and a permanent disorder of consciousness. When that response is delayed or mishandled, the question of negligence often follows.
The Three Stages of HIE
In newborns, severity is measured using the modified Sarnat staging score. In adults, similar grading is used to guide treatment and predict recovery. Both rely on the same broad framework: mild, moderate, and severe.
Mild HIE
Best PrognosisNewborns: Hyperalert, normal muscle tone, exaggerated reflexes. Symptoms typically resolve within 24-48 hours.
Adults: Brief confusion, agitation, or short-term memory disturbance. Most patients recover fully.
Moderate HIE
Cooling WindowNewborns: Lethargy, reduced muscle tone, weak suck reflex, and frequently seizures within the first 24 hours.
Adults: Prolonged altered consciousness, motor deficits, possible seizures. Rehabilitation is usually required.
Severe HIE
High RiskNewborns: Stuporous or comatose, flaccid tone, absent reflexes, and difficulty breathing without support. Often associated with prolonged seizures.
Adults: Coma, vegetative state, or minimally conscious state following the initial event.
What causes hypoxic ischemic encephalopathy?
The triggering events differ between newborns and adults, but the underlying injury - oxygen deprivation followed by reperfusion damage - is the same.
- Umbilical cord problemsCord prolapse, a true knot, or cord compression can interrupt the oxygen supply mid-labour.
- Placental abruptionPremature separation of the placenta from the uterine wall cuts off the baby's oxygen and nutrient supply.
- Uterine ruptureA rare but catastrophic event, particularly in attempted vaginal birth after Caesarean section.
- Shoulder dystociaWhen the baby's shoulder lodges behind the mother's pubic bone, oxygen flow can be compromised within minutes.
- Failure to monitor fetal heart rateMissed signs of fetal distress on the monitor strip are one of the most common allegations in birth injury claims.
- Delayed Caesarean sectionWhen fetal distress is recognized but the decision to deliver is not made quickly enough.
- Improper use of vacuum or forcepsInstrument-assisted deliveries that prolong oxygen deprivation rather than relieve it.
- Maternal hemorrhage or shockSevere blood loss in the mother reduces the oxygen reaching the placenta - and the baby.
Did clinicians miss the warning signs?
Many cases of newborn HIE involve a pattern of warning signs that were either not recognized, not communicated between staff, or not acted on in time. Common red flags in a chart review include:
- Non-reassuring fetal heart rate tracings left unaddressed
- Prolonged second stage of labour without intervention
- Meconium staining with no follow-up monitoring
- Delays between deciding on C-section and delivery
- Failure to offer therapeutic cooling within six hours
- Cardiac arrestThe leading cause of adult HIE. Outcomes depend heavily on how quickly CPR and defibrillation are started.
- Respiratory failureAcute lung events, severe asthma, pneumonia, or post-operative respiratory compromise.
- Anaesthesia complicationsFailed intubation, undetected oxygen desaturation during surgery, or post-operative monitoring lapses.
- Severe blood lossHemorrhagic shock during surgery, trauma, or postpartum complications.
- Drug overdoseOpioid and sedative overdoses are a growing cause of adult HIE across Canada.
- Near-drowningSubmersion injuries can cause profound hypoxia in minutes, especially when bystander CPR is delayed.
- StrokeAn ischemic stroke that interrupts blood flow to large regions of the brain.
- Carbon monoxide poisoningCarbon monoxide binds to hemoglobin and displaces oxygen, starving brain tissue even without circulatory failure.
Was care delayed or mismanaged?
Adult HIE claims often turn on the quality and speed of the emergency response. Issues that frequently appear in medical reviews include:
- Delayed recognition of a cardiac event in hospital
- Slow code blue response times
- Inadequate post-resuscitation care or temperature management
- Failure to monitor oxygen levels during or after anaesthesia
- Missed early signs of respiratory compromise on the ward
The six-hour window
For newborns diagnosed with moderate to severe HIE, the most effective treatment is therapeutic hypothermia - cooling the baby's body temperature to roughly 33.5C for 72 hours. Research has shown that cooling started within six hours of birth can meaningfully reduce death and long-term disability.
For adults following cardiac arrest, targeted temperature management serves a similar purpose: limiting the cascade of secondary brain injury that follows reperfusion.
When a hospital fails to identify HIE in time, fails to offer cooling, or delays transferring a baby to a regional centre with cooling capability, the family may have grounds for a medical malpractice claim. The same is true when an adult's targeted temperature management is delayed or skipped after a cardiac event.
The first six hours after a hypoxic event represent the brain's best chance at limiting permanent damage. Therapeutic hypothermia outside this window is far less effective.
A delay in diagnosis, transfer, or treatment within this window is one of the most consequential allegations in HIE litigation across Canada.
Long-term consequences of HIE
The lasting effects of HIE depend on which areas of the brain were affected, how long the oxygen interruption lasted, and how quickly treatment began.
Cerebral Palsy
HIE is among the leading causes of cerebral palsy in children, particularly the spastic and dyskinetic types.
Cognitive Disability
Learning difficulties, intellectual disability, and challenges with memory or executive function can persist into adulthood.
Seizure Disorders
Epilepsy and other seizure conditions are common consequences for both children and adults who survive moderate to severe HIE.
Motor Impairment
Difficulty with fine and gross motor skills, muscle stiffness or weakness, and challenges with balance and coordination.
Vision & Hearing Loss
Cortical visual impairment and sensorineural hearing loss are well-documented consequences of severe HIE.
Behavioural & Learning Challenges
ADHD, autism spectrum traits, and difficulty with social communication appear more frequently in children with a history of HIE.
Disorders of Consciousness
In severe adult cases, patients may emerge with a persistent vegetative or minimally conscious state requiring ongoing care.
Lifelong Care Needs
Many people with moderate or severe HIE require lifelong support: therapy, mobility aids, home modifications, and personal care.
Family & Emotional Impact
Families face enormous emotional, practical, and financial pressure. The cost of recovery extends far beyond the hospital bill.
When does HIE involve medical negligence?
Not every case of HIE involves negligence. Some are unavoidable, even with attentive care. But many are not. The legal question is whether a reasonable health care provider, in the same circumstances, would have acted differently - and whether that difference would have changed the outcome.
Medical malpractice claims for HIE typically focus on one or more of the following patterns. If any of these sound familiar from your experience, it may be worth a confidential conversation with a lawyer.
Speak to a lawyerFailure to monitor and respond
Fetal distress, oxygen desaturation, or early signs of cardiac compromise that should have triggered intervention but did not.
Delayed diagnosis or treatment
A delay between recognizing a problem and acting on it - whether that means ordering an emergency C-section or calling a code blue.
Missed cooling window
Failure to identify a newborn as a candidate for therapeutic hypothermia, or to transfer that baby to a regional centre in time.
Anaesthesia and airway errors
Failed intubation, missed disconnection, or inadequate monitoring of oxygenation during surgery.
Communication breakdown
Critical information about a deteriorating patient that was not communicated between nursing staff, residents, and attending physicians.
Inadequate post-event care
Failure to manage temperature, blood pressure, oxygenation, or seizures in the critical hours after a hypoxic event.
What a successful HIE claim may cover
The financial cost of an HIE injury is not measured by the first hospital bill. It is measured across a lifetime - therapy, equipment, lost income, and the cost of round-the-clock care.
A successful claim is built around hard numbers: medical reports, life-care plans, and economic projections that capture what recovery and ongoing support will actually cost.
Past Medical Expenses
Hospitalization, surgery, NICU stays, medications, imaging, and out-of-pocket costs already paid by the family.
Future Care Costs
Physiotherapy, occupational therapy, speech therapy, mental health support, and ongoing medical follow-up.
Specialized Equipment
Wheelchairs, communication devices, feeding equipment, and home or vehicle modifications.
Attendant & Personal Care
Costs of in-home care, respite care, and the value of unpaid family caregiving over a lifetime.
Loss of Future Earnings
For a child, the projected income they would have earned as an adult. For an adult survivor, lost wages and reduced earning capacity.
Pain & Suffering
Non-economic damages reflecting the physical pain, emotional distress, and loss of enjoyment of life.
HIE lawyers serving families across Canada
Diamond and Diamond Lawyers represent families in HIE and birth injury claims across Ontario, Alberta, and the Maritime provinces. Each province has its own limitation periods and procedural rules - here is what families in our key markets should know.
Toronto
Ontario, Canada
The Limitations Act, 2002 sets a general two-year period for civil claims. For a child injured at birth, the clock generally does not start until the child turns 18 - though earlier action almost always strengthens the case.
Halifax
Nova Scotia, Canada
The Nova Scotia Limitations Act sets a two-year limitation period, with similar tolling rules for minors and people under disability. Maritime families pursuing HIE claims should connect early to preserve evidence.
Calgary
Alberta, Canada
Alberta's Limitations Act sets a two-year discoverability period, with a fifteen-year ultimate limitation. For minors, the clock is paused. Our team handles HIE claims across Calgary and the broader province.
Edmonton & Region
Alberta, Canada
Beyond Calgary, our Alberta practice represents families in Edmonton, Red Deer, Lethbridge, and rural communities - including cases that involve transfers between regional and tertiary hospitals.
Frequently asked questions about HIE claims
The starting point is a careful review of the labour and delivery records, the fetal monitoring strips, the post-delivery course, and any imaging done in the days that followed. A medical malpractice lawyer will usually involve an independent medical reviewer - commonly an obstetrician or neonatologist - to assess whether the care provided fell below the standard expected. Families rarely have access to this analysis on their own, which is why the first call is often the most important step.
The limitation period in Ontario, Alberta, Saskatchewan, and Nova Scotia is generally two years from the date the harm was discovered or reasonably should have been discovered. For children injured at birth, the limitation period is typically paused until the child turns 18. Even with that pause, evidence becomes harder to recover the longer you wait - monitor strips can be lost, witnesses' memories fade, and records may be archived or destroyed. Acting early protects both the case and the family's options.
HIE is a brain injury caused by oxygen deprivation, usually identified in the hours or days after birth. Cerebral palsy is a lifelong motor disorder that can develop as a result of that injury - it is one of several possible outcomes of moderate or severe HIE. A child can be diagnosed with HIE shortly after birth and later receive a diagnosis of cerebral palsy as the long-term effects become clear, often around 18 to 24 months of age.
Yes, when there is evidence that the hospital's response fell below the standard of care. Common allegations include slow code blue response, missed early warning signs of cardiac compromise, errors in resuscitation, failed intubation, or inadequate post-resuscitation care. Adult HIE cases often turn on small windows of time - the difference between a defibrillation at two minutes versus six minutes is the difference between a likely recovery and a likely long-term disability.
Therapeutic cooling is the standard of care for newborns with moderate or severe HIE, when started within six hours of birth. In Canada, it is offered at tertiary neonatal intensive care units. Babies born at smaller hospitals are typically transferred for cooling, and the speed of that transfer matters. A failure to identify a baby as a cooling candidate, or a delay in transferring them, is a common allegation in HIE claims.
Diamond and Diamond Lawyers handle HIE and birth injury claims on a contingency basis. The initial consultation is free, and there are no upfront legal fees. We are paid a percentage of the settlement only if the case is resolved successfully. Medical malpractice litigation is long and document-heavy, but families do not need to fund it out of pocket while the case moves forward.
Keep everything: hospital discharge summaries, NICU notes, imaging reports, follow-up appointment records, therapy reports, and any correspondence from the hospital's patient relations office. Also keep a personal record of dates, names of staff involved, and your own recollection of what was said and when. The more contemporaneous the records, the more useful they are when a case is reviewed.
© 2025 Diamond and Diamond Lawyers LLP. All Rights Reserved.