Magnesium sulphate for neuroprotection Flashcards
Definition: cerebral palsy
Cerebral palsy describes a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain.
The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication, and behaviour, by epilepsy, and by secondary musculoskeletal problems.
Definition: Cognitive dysfunction
Poor mental function, such as, difficulties with lack of attention, memory and problem solving
Definition: Developmental delay
Any significant lag in a child’s physical, cognitive, behavioural, emotional, or social development, in comparison with norms.
Definition: intraventricular haemorrhage
Bleeding inside or around the ventricles, the spaces in the brain containing the cerebrospinal fluid.
Intraventricular haemorrhage can be graded based on the severity of the haemorrhage. Grades 3 and 4 represent more severe haemorrhage causing
ventriculomegaly or venous infarction of the brain respectively and are more likely to be associated with neurologic disability.
Definition: necrotising enterocolitis
A medical condition primarily seen in premature infants, where portions of the bowel undergo tissue death (necrosis).
Definition: periventricular leukomalacia
A form of brain injury characterised by the death of white matter near the cerebral ventricles in newborns due to damage and softening of the brain tissue.
When to use magnesium sulphate?
In women at risk of early preterm* imminent birth, use magnesium sulphate for neuroprotection of the fetus, infant and child:
- when gestational age is less than 30 weeks.
- when early preterm birth is planned or definitely expected within 24 hours. (When birth is planned, commence magnesium sulphate as close to four hours before birth as possible).
Regardless of:
- Reason for PTB
- MOD
- Plurality
- Parity
- whether steroids have been given
Dosage of magnesium sulphate?
IV 4 gram loading dose (slowly over 20-30
minutes) and 1 gram per hour maintenance dose via intravenous route, with no immediate repeat doses.
Continue regimen until birth or for 24 hours, whichever comes first.
In the event of urgent delivery:
In situations where urgent delivery is necessary because of actual or imminent maternal or fetal
compromise (e.g. severe fetal distress or antepartum haemorrhage), then birth should not be
delayed to administer magnesium sulphate.
If delivery hasn’t occured within 24 hours of administering MgSO4
In the event that birth does not occur after giving magnesium sulphate for neuroprotection of the
infant, and preterm birth (less than 30 weeks’ gestation) again appears imminent (planned or
definitely expected within 24 hours), a repeat dose of magnesium sulphate may be considered at the
discretion of the attending health professional
Monitoring of loading dose of MgSO4?
A minimum assessment:
- pulse,
- BP
- RR
- Patellar reflexes
before loading dose, 10 minutes after loading dose infusion has started and at the end of the loading dose infusion (20-30 minutes).
Stop infusion if respiratory rate <4 or >12 or
diastolic blood pressure decreases > 15 mm Hg below baseline level.
Monitoring of maintenance dose of MgSO4?
Observe for any adverse effects.
The minimum assessments:
- pulse,
- BP
- RR
- Patellar reflexes
- Urine output
Frequency: 4-hourly.
Stop infusion if respiratory rate < 12, if patellar
reflexes are absent, if hypotension occurs or if urine output is less than 100 mL over 4 hours.
Who is at increased risk of MgSO4 toxicity?
Women with abnormal renal function- in this case monitor magnesium levels
What to do in the event of MgSO4 toxicity?
- Stop infusion
- A-E resus - consider O2, breathing support, BP support
- Assess woman
- Administer calcuium gluconate e (1 g (10 mL of 10% solution) slowly via intravenous route over 10 minutes) if concern re respiratory depression
Results of 2009 cochrane review for MgSO4
Included 4 trials, >4000 children
Found:
- Reduction in CP (RR 0.71, NNT 63)
- NNTB for combined reduction in CP and death is 42
No statistically significant change in rates of PVH/leukomalacia
Trials mostly looked at babies born <30-32/40 therefore recommendation for MgSO4 is for <30/40
significant proportion of the women involved in the trial had PPROM
