ASFIXIA PERINATAL /NEONATOLOGÍA ENAM 2020

Neonatology: Perinatal Asphyxia

The discussion delves into perinatal asphyxia, a condition characterized by a state of hypoxia affecting the entire body. Key points include the impact on vital organs like the kidneys and liver, as well as the neurological damage associated with perinatal asphyxia.

Understanding Perinatal Asphyxia

• Perinatal asphyxia can lead to damage in various organs such as the kidneys, liver, respiratory system, and neurological system.

• Neurological damage within perinatal asphyxia is referred to as hypoxic-ischemic encephalopathy, emphasizing its impact on the central nervous system.

• Perinatal asphyxia can occur before birth (antepartum), after birth (postpartum), but most commonly during labor (intrapartum).

Physiological Progression of Asphyxia

• The physiological progression of perinatal asphyxia involves irregular breathing patterns leading to primary apnea followed by secondary apnea if spontaneous breathing does not resume.

• Distinguishing between primary apnea (self-resolving irregular breathing) and secondary apnea (requiring intervention for resumption of breathing).

Differentiating Respiratory Pauses

• Understanding the difference between respiratory pauses lasting less than 20 seconds and true apnea lasting more than 20 seconds, considering associated symptoms like bradycardia or altered consciousness.

• Even if a pause in breathing is brief but accompanied by concerning symptoms like bradycardia or altered sensorium, it should be considered apnea.

Impact on Premature Infants

• Premature infants are more prone to respiratory pauses and apneas compared to full-term infants, with frequency decreasing as gestational age increases.

• The incidence of primary and secondary apneas decreases with increasing corrected gestational age in premature infants.

Physiological Consequences of Perinatal Asphyxia

This segment explores how perinatal asphyxia affects physiological parameters such as heart rate, cardiac output, blood pressure, and metabolic balance leading to metabolic disturbances like acidosis.

Physiological Cascade in Asphyxia

• Perinatal asphyxia leads to a decline in heart rate affecting cardiac output and blood pressure while compromising organ perfusion.

• Metabolic consequences include acidosis due to decreased oxygen levels and increased CO2 levels impacting pH balance—a triad known for patients with perinatal asphyxia: acidosis, hypoxemia, hypercapnia.

Neurological Damage Assessment

• Neurological damage becomes evident around the 10-minute mark post-asphyxial event necessitating close monitoring for signs of neurological impairment.

Diagnostic Criteria for Perinatal Asphyxia

• Diagnostic criteria according to American Academy of Pediatrics include Apgar score <3 at 5 minutes post-birth and cord pH <7 indicating acidosis—essential indicators for diagnosing perinatal asphyxia.

Understanding Perinatal Asphyxia and its Consequences

In this section, the speaker discusses perinatal asphyxia, highlighting its impact on various organs and systems in the body.

Perinatal Asphyxia Effects

• Perinatal asphyxia leads to a state of whole-body hypoxia, potentially causing lung damage and respiratory failure.

• Evidence of asphyxia damage includes renal failure, hepatic failure, and neurological manifestations like seizures.

• Primary apnea management involves stimulation to prompt breathing; however, secondary apnea requires neonatal resuscitation protocols.

• Neonatal resuscitation aims to improve respiratory patterns, cardiac function, blood pressure, and organ perfusion.

• Improvement in cardiac function precedes respiratory improvement during neonatal resuscitation.

Understanding Hypoxic-Ischemic Encephalopathy Classification

This segment delves into hypoxic-ischemic encephalopathy (HIE), detailing its association with perinatal asphyxia and introducing the Karnak classification system.

HIE Classification Parameters

• Perinatal asphyxia can lead to central nervous system damage known as hypoxic-ischemic encephalopathy.

• The Karnak classification categorizes HIE into three grades: mild (grade 1), moderate (grade 2), and severe (grade 3).

• Parameters for classifying HIE include sensorium status ranging from hyper-alertness in grade 1 to deep stupor or coma in grade 3.

• Suction ability decreases from active suction in grade 1 to absent suction in grade 3 with worsening HIE severity.

New Section

In this section, the speaker discusses the characteristics of low voltage programs and epileptic activity. They delve into the periodic nature of epileptic activity and its implications.

Characteristics of Epileptic Activity

• Low voltage programs or a decrease in voltage can indicate epileptic activity.

• Epileptic activity can manifest periodically or paroxysmally.

• The severity of epilepsy can be classified into different grades, with grade 3 indicating periodic activity.

New Section

This part focuses on the impact of neural damage on brain function and the importance of assessing severity in medical conditions.

Impact of Neural Damage

• Neural damage can lead to flattened waves, signifying severe neural damage.

• Assessing severity is crucial for understanding prognosis and mortality rates in medical conditions.

• Severity assessment helps determine appropriate treatment strategies based on consensus guidelines.

New Section

The discussion shifts towards treatment options for hypoxic-ischemic encephalopathy, emphasizing therapeutic hypothermia as an effective intervention.

Treatment for Hypoxic-Ischemic Encephalopathy

• Consensus guidelines recommend therapeutic hypothermia as the most effective treatment.

• Therapeutic hypothermia aims to halt detrimental metabolic pathways that exacerbate neurological damage.

• Early initiation of therapeutic hypothermia is vital for optimal outcomes in patients with hypoxic-ischemic encephalopathy.

New Section

Exploring the rationale behind therapeutic hypothermia, focusing on its role in mitigating neurological damage through metabolic pathway modulation.

Rationale for Therapeutic Hypothermia

• Therapeutic hypothermia targets metabolic pathways triggering neurological damage.

• By inhibiting these pathways, therapeutic hypothermia aims to reduce neurological harm.

• Effective application of therapeutic hypothermia hinges on early initiation and adherence to temperature control protocols.

New Section

Delving into the practical aspects of implementing therapeutic hypothermia, including timing considerations and target temperature ranges.

Implementation of Therapeutic Hypothermia

• Initiate therapeutic hypothermia within six hours post-birth to capitalize on the optimal treatment window.

• Maintain patient temperature between 33 to 34 degrees Celsius during therapy.