Gas gangrene

Disease Description (Causes and Symptoms)

Neonatal asphyxia is a hypoxic and hypoperfusion state that occurs when systemic circulation in the fetus or newborn is insufficient at any time before, during, or after delivery, impairing carbon dioxide elimination and oxygen supply. If it persists, ischemic injury and metabolic disturbances (metabolic acidosis, hypoglycemia, etc.) occur in multiple organs, including the brain, heart, kidneys, liver, lungs, and gastrointestinal tract.

Major causes

• Fetal factors: intrauterine growth restriction, prematurity/post-term birth, hemolytic disease, meconium aspiration
• Maternal/pregnancy factors: diabetes mellitus, eclampsia, hypotension/hypertension, bleeding, multiple pregnancy, drug or alcohol intoxication
• Delivery factors: difficult labor, umbilical cord compression or prolapse, placenta previa or placental abruption, indications for cesarean section, premature rupture of membranes, infection, etc.

Pathophysiology (summary) Initially, blood flow to the kidneys, gastrointestinal tract, skin, liver, muscles, and lungs decreases due to blood-flow redistribution. If the condition persists, cerebral and cardiac blood flow also decreases because of reduced cardiac output, progressing to multiple-organ injury. After primary apnea, newborns deteriorate to secondary apnea if appropriate stimulation and oxygen supply are not provided.

Major symptoms

• Respiratory: apnea, respiratory distress, cyanosis, respiratory failure
• Central nervous system: decreased consciousness, decreased muscle tone, pupillary changes, seizures
• Cardiovascular: shock, hypotension, arrhythmia
• Renal/gastrointestinal: oliguria, necrotizing enterocolitis
• Metabolic: hypothermia, metabolic acidosis, hypoglycemia, electrolyte abnormalities

Findings helpful for diagnosis: low Apgar score, severe acidosis in umbilical cord or neonatal arterial blood gases (decreased pH, increased base deficit), abnormal fetal heart rate, abnormal neurological findings, and exclusion of other causes.

Treatment Methods

Goal: Restore oxygen supply and blood flow through immediate resuscitation, preserve organ function, and prevent complications

Acute phase (immediately after birth)

• Immediate resuscitation (according to neonatal resuscitation guidelines): securing the airway, positive-pressure ventilation (artificial ventilation), chest compressions, and medications (such as epinephrine) if necessary
• Oxygen therapy: adjust the oxygen concentration appropriately (avoid hyperoxia)
• Mechanical ventilation and hemodynamic support (fluid therapy, vasoactive agents)
• Wound and airway suctioning (management of meconium aspiration if necessary)

Critical care

• Continuous monitoring and organ-specific supportive treatment in the neonatal intensive care unit (ventilator support; ECMO may be considered in severe cases)
• Metabolic correction: correction of acidosis, hypoglycemia, and electrolyte abnormalities
• Administration of anticonvulsants if seizures occur (e.g., phenobarbital, levetiracetam)
• Administration of antibiotics if infection is suspected

Specific treatment

• Therapeutic hypothermia: Usually considered for moderate to severe hypoxic-ischemic encephalopathy (HIE) in full-term or near-term newborns (≥36 weeks), and should be initiated within 6 hours after birth whenever possible. It has been shown to improve neurological outcomes in some cases, but it is not indicated for every patient.

Follow-up and rehabilitation

• Neurodevelopmental assessment and rehabilitation (physical, occupational, and speech therapy) are necessary
• Long-term examinations: hearing tests, vision tests, and monitoring of growth and development

Precautions (self-care and in-hospital)

• During the acute phase, the prognosis can rapidly worsen if emergency resuscitation is delayed.
• Therapeutic hypothermia has strict indications, contraindications, and implementation protocols and should be performed only at specialized institutions.
• Attention should be paid to infection control, maintaining body temperature, and blood glucose management.

Risk of complications

• Neurological sequelae (hypoxic encephalopathy, cerebral palsy, developmental delay)
• Kidney (acute renal failure), gastrointestinal tract (necrotizing enterocolitis), lungs (meconium aspiration syndrome, persistent pulmonary hypertension), coagulation disorders (disseminated coagulation disorder), liver dysfunction, etc.

Prognostic factors

• Severity and duration of hypoxia, gestational age, promptness of early postnatal treatment, and presence or absence of concurrent infection or metabolic disorders

Outpatient Visit Checklist (Including Example Questions)

Items to bring

• Birth records (delivery records), Apgar score, umbilical cord blood gas results (if available)
• Neonatal intensive care unit admission and discharge summary, medication records
• Current medications (including information on the mother’s medications if breastfeeding)
• Recent test results (blood tests, electroencephalogram (EEG), brain ultrasound/MRI, etc.)
• Records of observed changes in seizures, feeding, urination, bowel movements, and body temperature (by time of day)

Items to check in advance at the outpatient visit (examples)

• Current feeding amount/method (breast milk/formula) and weight changes
• Presence and type of seizures (time of seizure onset, duration, and response)
• Episodes of respiratory distress, cyanosis, or apnea
• Digestive symptoms such as decreased urine output, abdominal distension, or vomiting
• Changes in developmental milestones (smiling, head control, rolling over, etc.)

Example questions (for the patient’s guardian to prepare)

• Has there been a recent seizure? When and how did it occur?
• How have the feeding amount and weight changed recently?
• What are the frequency and color of the child’s urine and stool?

General Example Questions to Ask the Doctor

• How can you distinguish whether the child’s condition is the result of asphyxia or another cause?
• What do the current test findings (brain MRI/EEG, blood tests) mean?
• Does this child meet the indications for therapeutic hypothermia? What are its advantages and disadvantages?
• What complications are possible, and how high is the risk that they will occur?
• What is the plan for future follow-up tests and rehabilitation (when and how should they begin)?
• What should we watch for at home after discharge, and how should we respond in an emergency?

Disease-Specific Example Questions

• If therapeutic hypothermia was performed: "What neurological tests and follow-up schedule will you use after hypothermia treatment? How might the long-term prognosis change?"
• If seizures are present: "What medication do you plan to use to control the seizures? What side effects are expected, and when will the medication be discontinued?"