Neonatal Neuro Flashcards
Define neonatal encephalopathy
- Heterogeneous (diverse in character)
- Clinically defined syndrome characterized by disturbed neurologic function in an infant greater than 35 weeks of gestation
- Key features: Reduced level of consciousness or seizures, often accompanied by difficulty with initiating and maintaining respiration, and by depression of tone and reflexes
Causes of neonatal encephalopathy
- HIE
- Perinatal stroke (arterial ischemic stroke, cerebral sinovenothrombosis CSVT, hemorrhage stroke, Periventricular venous infarction PVI)
- Metabolic (hypoglycemia, inborn error of metabolism
- structural brain abnormalities
- maternal tox (opiates, barbs, etoh, tca, SSRI)
Types of perinatal strokes
Arterial Ischemia: Commonly arterial infarction in the distribution of the middle cerebral artery (cardiac, disorders of cerebral arteries, disturbed heomostasis, embolism, infection, trauma, primary thrombosis)
Thromoembolism: Secondary to possible placental vasculature thrombus, venous clots crossing PFO, R-L shunt secondary to CHD, emboli from indwelling catheters
Cerebral sinovenous thrombosis — Cerebral sinovenous thrombosis (CSVT) can cause venous infarction, often associated with hemorrhage (ie placental lesions casing an inflammatory process, or damage to cerebral sinus structures during a traumatic birth
Hemorrhagic stroke — neurologic syndromes resulting from intracranial hemorrhage of nontraumatic origin. It has two main forms: Hemmorhagic transformation of a ischemic infarct or primary cerebral hemorrhage
Periventricular hemorrhagic infarction — spectrum of germinal matrix and intraventricular hemorrhage. Most common in premature infants, but can also been seen in term and near-term infants. Occurs in approximately 15 to 20 percent of premature infants with intraventricular hemorrhage. Mechanism is obstruction of the medullary and terminal veins by the associated intraventricular hemorrhage, resulting in periventricular venous congestion, ischemia, and venous hemorrhagic infarction
HIE criteria
- < 6hrs (can consider up to 8hrs)
- > 35wks
Cord PH < 7 or BD > -16
OR
PH 7.01-7.15 or BD -10 - 15.9 (cord or in 1st hr)
+
Sentinal event AND APGAR <5 @ 10m or > 10mPPV
with
evidence of mod-severe encephalopathy (seizures or >3 in AET table)
Process of HIE initiation
- turn off warmer
- temps Q 15m or rectal temp (target 33.5 +/- 0.5)
- start D10W ASAP, measuring glue q 30min-1hr (goal BG 3-6mmol)
- consider morphine to inhibit shivering (0.1mg/kg loading, 10-20mcg/kg/hr infusion)
- reduce TFI (ie D10W day 1 50ml/kg/day)
- HR should decrease to 80-100 ( consider dobutamine as first line inotrope if required)
- micro-repositioning to avoid necrosis
- Important to report time to target temp. pt will be cooled for 72hrs total
- Assess CBC an lytes
- BG 3.3-6mmol (repeat q 6hrs)
- ical > 1
- platlets > 100
- Na > 130
- K > 3 < 6
- HgB (100 1st wk, 85 2nd, 70 3rd)
Complications of cooling
- bradycardia
- hypotension
- thrombocytopenia
- PPHN
- subcutaneous fat necrosis
- hypercalcemia
Risk factors for IVH
- pre-term
- instrument use at birth
- Large BP variations
- acidosis
- improper suctioning
- resp distress
- irritation
- anemia
- coagulopathy
- sinovenousthromus
- ECMO (mainly due to the hypothermia)
Most common location of IVH in neonates
- within the capillary network of the germinal matrix located between the caudate nucleus and the thalamus at the level of the foramen of Monro.
- IVH is due to infarction caused by impaired venous drainage of the medullary veins in the white matter
Neonatal maintenance fluid based on weight
< 1000 g - 80-100 ml/kg/day, + 15-20ml/kg/day up to 160 @ 1wk
1000-1500g- 80ml/kg/day, + 15-20ml/kg/day up to 150 @ 1wk
> 1500g 60ml/kg/day, + 15-20ml/kg/day up to 150 @ 1wk
Electrolyte requirements
first 24hr no electrolytes required due to immature kidneys ** pre-term may require Na due to high urinary losses
day 3-7 Na, K and Cl 2-3mEq/kg/day
> 1wk NA and Cl 2-3ml/kg/day for tissue development
what is automatism
cycling, lip smacking etc no stopped with pressure
Neonatal seizure management algorithm
1- Phenobarbital (loading 20mg/kg/dose IV over 20min)
2- Phenobarbital ( 10mg/kg/dose IV)
3- Phenobarbital ( 10mg/kg/dose IV)
4- Fosphenytoin (20mg/kg IV)
5- Levetiracetam (40-60 mg/kg IV Loading)
6- Midazolam (0.15-0.2 mg/kg + Infusion (starting 1-2mg/kg/hr))
Birth related traumas
- Intracranial (SD, SA, EPI)
- Extra-axial: Subgaleal, caput secundum, cephalopodslohematoma
- skull#s
- Branchial plexus injuries
What 2 seizure disorders cannot receive Na channel blockers (phenytoin)
- Dravet syndrome
- Lennox-Gastaut syndrome
