Download Magnesium Sulphate for Fetal Neuroprotection

Title of Guideline (must include the word “Guideline” (not protocol, policy, procedure
etc)
Antenatal Magnesium Sulphate for Fetal
Neuroprotection Guideline
Author: Contact Name and Job Title
Directorate & Speciality
Dr. Suma Devi Kodiathodi, Post CCT Fellow,
Obstetrics and Gynaecology
Nottingham University Hospitals NHS Trust
Dr . H. Kok, ST1, Obstetrics and Gynaecology.
Nottingham University Hospitals NHS Trust
Prof. Jim Thornton, Professor, Obstetrics and
Gynaecology, Nottingham University Hospitals
NHS Trust
Family Health
Obstetrics and Gynaecology
Date of submission
October 2015
Explicit definition of patient group to which it applies (e.g. inclusion and exclusion
criteria, diagnosis)
Women at 30 weeks gestation or less where
delivery is planned or definitely expected within
24 hrs
Version
2
If this version supersedes another clinical guideline please be explicit about which
guideline it replaces including version number.
Version 1
Statement of the evidence base of the guideline – has the guideline been peer
reviewed by colleagues?
2a
Evidence base: (1-6)
1
NICE Guidance, Royal College Guideline, SIGN (please state
which source).
2a
2b
3a
meta analysis of randomised controlled trials
at least one randomised controlled trial
at least one well-designed controlled study without
randomisation
3b
at least one other type of well-designed quasi-experimental
study
4
well –designed non-experimental descriptive studies (ie
comparative / correlation and case studies)
5
expert committee reports or opinions and / or clinical
experiences of respected authorities
6
recommended best practise based on the clinical experience of
the guideline developer
Consultation Process
Obstetricians, midwives and neonatologist.
Ratified by:
Maternity guideline Group
Date:
5 October 2015
Target audience
Midwives
Obstetricians
Neonatologists
th
Review Date: (to be applied by the Integrated Governance Team)
October 2020
A review date of 5 years will be applied by the Trust. Directorates can choose to
apply a shorter review date, however this must be managed through Directorate
Governance processes.
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This guideline has been registered with the trust. However, clinical guidelines are guidelines only. The
interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If
in doubt contact a senior colleague or expert. Caution is advised when using guidelines after the review
date.
NHS Nottingham City and Nottingham University Hospitals NHS Trust are committed to ensuring that, as far
as is reasonably practicable, the way we provide services to the public and the way we treat our staff reflects
their individual needs and does not discriminate against individuals or groups on the basis of their ethnic
origin, physical or mental abilities, gender, age, religious beliefs or sexual orientation.
The Trusts are committed to ensuring that the public and staff are given information in a clear and concise
way and in a manner that people understand. In situations where there are concerns about an individual’s
ability to understand information or consent to treatment because a medical condition has affected their
cognitive functioning and mental capacity please refer to the Mental Capacity Act intra-agency guidance and
complete appropriate documentation.
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ANTENATAL MAGNESIUM SULPHATE FOR FETAL
NEUROPROTECTION
Objectives:
There is evolving body of evidence to support the role of
magnesium sulphate in reducing the risk of cerebral palsy. This
guideline aims to assist clinicians caring for women presenting with
preterm labour in deciding on when and how to administer
magnesium sulphate (MgSO4) prior to preterm birth for fetal
neuroprotection.
Clinical indications for use of MgSO4 in preterm labour for
neuroprotection of the fetus
MgSO4 for neuroprotection of the fetus should be considered in
women at 30 weeks’ gestation or less where a viable outcome is
anticipated and where delivery is planned or definitely expected
within 24 hours. MgSO4 should be considered regardless of:




Singleton or multiple pregnancy
The risk factor for preterm birth
The expected mode of delivery
Whether antenatal corticosteroids
administered.
have
already
been
Decision
The final decision on MgSO4 administration should be made by
either the Consultant on call or senior registrar.
Administration
Magnesium sulphate regimen
Loading dose:
 Give 4g MgSO4 intravenously over 20 minutes via an
infusion pump. (as per severe pre-eclampsia and eclampsia
guidelines, NUH)
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Maintenance dose:
 Continue to infuse MgSO4 intravenously at 1g/hr (as per
severe pre-eclampsia and eclampsia guidelines, NUH)
 Continue regimen until birth or for 24 hours, whichever
comes first
Maternal Monitoring
Loading
 Pulse rate, blood pressure, respiratory rate and patellar
reflex before loading dose
 Repeat after 10 min
 Repeat at the end of loading dose infusion (20 min)
Discontinue MgSO4 loading infusion if:
 Respiratory rate decreases by more than 4 breaths/min
below baseline or is less than 12 breaths/min
 Diastolic BP decreases more than 15mm Hg below baseline
During MgSO4 therapy:
 Urine output should be monitored hourly
 Respiratory rate should be monitored hourly
 Blood pressure should be monitored 2 hourly
 Reflexes and mental status monitored 4-6 hourly
Discontinue MgSO4 if:
 The woman becomes hypotensive with mother or baby
becoming symptomatic
 Respiratory rate decreases below 12/min
 Urine output < 100mls/4hrs
 Tendon reflexes are not elicited (see MgSO4 over dosage
section below)
In this case, stop the infusion and check magnesium levels
urgently. Remember to assess elbow (rather than knee) jerks in
someone with an epidural analgesia.
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Magnesium Sulphate over dosage
If this is suspected, stop the MgSO4 infusion. MgSO4 is excreted
by the kidneys. Attention must be paid to urine output and
magnesium levels. Patients with a normal urine output are unlikely
to exceed therapeutic levels, but in oliguric or anuric patients there
is a real danger. Nifedipine and muscle relaxants used in
association with MGSO4 can potentiate hypotension leading to
oliguria.
With MgSO4 overdosage, vital functions are lost in the following
sequence:
 Loss of tendon reflexes
 Somnolence
 Respiratory depression
 Paralysis
 Cardiac arrest.
In case of overdosage warranting immediate reversal (discuss with
consultant/senior registrar), the antidote is 10mL calcium gluconate
10% (1g) intravenously over 3 minutes.
Fetal monitoring
In the absence of complications, fetal monitoring from 26+0 weeks
gestation should be performed as per the fetal monitoring
guideline.
Place of administration
Because of the potential for respiratory depression, hypotension
leading to maternal and fetal compromise, MgSO4 should be
administered where there is appropriate staff and resources for
adequate maternal and fetal monitoring, on the labour suite or in
theatre (Walker 2010).
Drug precautions
No significant side effects have been demonstrated, apart from
minor side effects including maternal flushing, hypotension and
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tachycardia (Walker 2010). Other side effects include nausea,
vomiting, headache, palpitations and rarely pulmonary oedema.
Timing
Even if delivery is imminent consider magnesium sulphate as there
is benefit likely in women at risk of preterm birth
Urgent delivery
In situations where urgent delivery is necessary because of actual
or imminent maternal or fetal compromise (e.g. severe fetal
compromise or antepartum haemorrhage), then birth should not be
delayed to administer magnesium sulphate.
Repeat doses
In the event that birth does not occur after giving MgSO4 for fetal
neuroprotection, and preterm birth less than 30 weeks’ gestation
again appears imminent (planned or definitely expected within 24
hours), a repeat dose of MGSO4 may be considered at the
discretion of the attending health professional.
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Flowchart
Less than 30+0 weeks gestation with preterm delivery imminent or planned within 24 hrs
Is urgent delivery is necessary because of actual or imminent maternal or fetal compromise (e.g.
severe fetal compromise or antepartum haemorrhage)?
No
Yes
EXPEDITE DELIVERY.
Do NOT delay delivery to administer MgSO4
Discuss with Senior Registrar / Consultant and
counsel patient about MgSO4 administration and
fetal neuroprotection
If preterm delivery is anticipated within 4hrs:
Administration of MgSO4 still offers some benefit to
the preterm fetus and therefore should still be
given
Administer MgSO4 infusion
Irrespective of:
 Singleton or multiple pregnancy
 Mode of delivery
 Reason of preterm birth
 Whether or not antenatal steroids have been administered
MATERNAL MONITORING: During MgSO4 therapy:
 Urine output, respiratory rate should be monitored hourly
 Blood pressure should be monitored 2 hourly
 Reflexes and mental status monitored 4-6 hourly
FETAL MONITORING:
 In the absence of complications, fetal monitoring after 26+0weeks gestation should
be performed as per fetal monitoring guideline
Continue MgSO4 for 24 hours or up to delivery of fetus unless:
 The women becomes hypotensive
 Respiratory rate decreases below 12/min
 Urine output < 100 mls/4hrs or tendon reflexes are not elicited
If MgSO4 overdosage suspected:
 Stop infusion
 Contact senior registrar or Consultant
 Reversal with 10mL calcium gluconate 10% (1g) intravenously over 3 minutes may
be needed
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References:
1. The Antenatal Magnesium Sulphate for Neuroprotection
Guideline Development Panel. Antenatal magnesium
sulphate prior to preterm birth for neuroprotection of the
fetus, infant and child: National clinical practice guidelines.
Adelaide: The University of Adelaide, 2010.
2. Crowther CA, Hiller JE, Doyle LW, Haslam RR for the
Australasian Collaborative trial of Magnesium Sulphate
(ACTOMgSO4) Collaborative Group. Effect of magnesium
sulphate given for neuroprotection before preterm birth.
JAMA 2003:290(20):2669-76.
3. Doyle, LW, CA Crowther, P Middleton, S Marret, and D
Rouse. ”Magnesium sulphate for women at risk of preterm
birth for neuroproctection of the fetus.” Cochrane Database
of Systematic Reviews, no. 1 (2009).
4. Himpens, E, C Van der Broeck, A Oostra, P Calders, and P
Vanhaesebrouck. ”Prevalence, type, distribution and severity
of cerebral palsy in relation to gestational age: a metaanalytic review.” Dev Med Child Neurol 50, no. 5 (May
2008): 334-40.
5. Kuban KC, Leviton A, Pagano M, Fenton T, Strassfeld R,
Wolff M. “Maternal toxemia is associated with reduced
incidence of germinal matrix hemorrhage in premature
babies.” J Child Neurol. 1992 Jan;7(1):70-6.
6. National Health Service. Cerebral palsy - Introduction. June
29,2010.http://www.nhsinform.co.uk/healthlibrary/articles/c/
cerebral- palsy/introduction.aspx (accessed August 25,
2010).
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7. Rouse, DJ. ”Magnesium sulphate for the prevention of
cerebral palsy.” Am J Obstet Gynecol 200 (2009): 610-2.
8. Walker, S. “Magnesium sulphate in women at risk of preterm
birth for neuroprotection of the fetus.” O&G Magazine 12, no.
2 (Winter 2010): 1-4.
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