General obstetrics
DOI: 10.1111/1471-0528.12535 www.bjog.org
Maternal adverse effects with different loading infusion rates of antenatal magnesium sulphate for preterm fetal neuroprotection: the IRIS randomised trial ES Bain,a PF Middleton,a LN Yelland,a PJ Ashwood,a CA Crowthera,b a
Australian Research Centre for Health of Women and Babies, Robinson Institute, School of Paediatrics and Reproductive Health, The University of Adelaide, Adelaide, Australia b The Liggins Institute, The University of Auckland, Auckland, New Zealand Correspondence: Ms ES Bain, Australian Research Centre for Health of Women and Babies, Robinson Institute, School of Paediatrics and Reproductive Health, The University of Adelaide, Women’s and Children’s Hospital, 72 King William Road, North Adelaide 5006, SA, Australia. Email [email protected] Accepted 14 September 2013. Published Online 6 January 2014.
Objective To evaluate a slower (compared with a standard)
infusion rate of the loading dose of magnesium sulphate for preterm fetal neuroprotection as a strategy to reduce maternal adverse effects. Design Randomised controlled trial. Setting South Australian maternity hospital. Population Fifty-one women at 15 mmHg from
Table 1. Any maternal adverse effects of the magnesium sulphate infusion (primary outcome) Outcome
Any adverse effects Adverse effects over time 20 minutes 60 minutes
60-minute loading n = 25
20-minute loading n = 26
RR (95% CI)
P
15 (60.0)
21 (80.8)
0.74 (0.51–1.08)
0.12
14 (56.0) 14 (56.0)
20 (76.9) 11 (42.3)
0.73 (0.48–1.09) 1.32 (0.75–2.34)
0.13 0.33
Interaction P*
0.01
Values are n and %. *Treatment by time interaction P-value.
598
ª 2014 Royal College of Obstetricians and Gynaecologists
Magnesium sulphate infusion adverse effects
Table 2. Secondary maternal outcomes assessed during treatment Outcome
Cardiac arrest Respiratory arrest Death Any respiratory rate of 15 mmHg Loading infusion ceased for adverse effects Any warmth over body Any arm discomfort Any mouth dryness Any mild nausea Any sleepiness Any sweating Any blurred vision Any palpitations Any headache Any dizziness Any muscle weakness Any respiratory depression*** Any maternal tachycardia***
60-minute loading n = 25 0 0 0 0 1 1 9 13 3 3 2 2 0 0 2 1 1 1 1
(0.0) (0.0) (0.0) (0.0) (4.0) (4.0) (36.0) (52.0) (12.0) (12.0) (8.0) (8.0) (0.0) (0.0) (8.0) (4.0) (4.0) (4.3) (4.3)
20-minute loading n = 26 0 0 0 3 2 2 16 17 8 7 5 4 2 2 1 1 1 0 2
(0.0) (0.0) (0.0) (13.6) (7.7) (7.7) (61.5) (65.4) (30.8) (26.9) (19.2) (15.4) (7.7) (7.7) (3.8) (3.8) (3.8) (0.0) (9.5)
RR (95% CI)
P
Not Estimable Not Estimable Not Estimable Not Estimable* 0.52 (0.05–5.38) 0.52 (0.05–5.38) 0.59 (0.32–1.07) 0.80 (0.50–1.27) 0.39 (0.12–1.31) 0.45 (0.13–1.53) 0.42 (0.09–1.95) 0.52 (0.10–2.59) Not Estimable* Not Estimable* 2.08 (0.20–21.52) 1.04 (0.07–15.74) 1.04 (0.07–15.74) Not Estimable* 0.46 (0.04–4.68)
0.11 0.58 0.58 0.08 0.34 0.13 0.20 0.27 0.42 0.49 0.49 0.54 0.98 0.98 1.00 0.51
Values are n and %, unless stated otherwise. *P-value based on Fisher’s exact test. **n = 23, 60-minute loading; n = 22, 20-minute loading. ***n = 23, 60-minute loading; n = 21 20-minute loading.
baseline. In the 20-minute loading group, two (8%) women experienced a decrease in diastolic blood pressure of >15 mmHg from baseline, and three (14%) women experienced a respiratory rate of
DOI: 10.1111/1471-0528.12535 www.bjog.org
Maternal adverse effects with different loading infusion rates of antenatal magnesium sulphate for preterm fetal neuroprotection: the IRIS randomised trial ES Bain,a PF Middleton,a LN Yelland,a PJ Ashwood,a CA Crowthera,b a
Australian Research Centre for Health of Women and Babies, Robinson Institute, School of Paediatrics and Reproductive Health, The University of Adelaide, Adelaide, Australia b The Liggins Institute, The University of Auckland, Auckland, New Zealand Correspondence: Ms ES Bain, Australian Research Centre for Health of Women and Babies, Robinson Institute, School of Paediatrics and Reproductive Health, The University of Adelaide, Women’s and Children’s Hospital, 72 King William Road, North Adelaide 5006, SA, Australia. Email [email protected] Accepted 14 September 2013. Published Online 6 January 2014.
Objective To evaluate a slower (compared with a standard)
infusion rate of the loading dose of magnesium sulphate for preterm fetal neuroprotection as a strategy to reduce maternal adverse effects. Design Randomised controlled trial. Setting South Australian maternity hospital. Population Fifty-one women at 15 mmHg from
Table 1. Any maternal adverse effects of the magnesium sulphate infusion (primary outcome) Outcome
Any adverse effects Adverse effects over time 20 minutes 60 minutes
60-minute loading n = 25
20-minute loading n = 26
RR (95% CI)
P
15 (60.0)
21 (80.8)
0.74 (0.51–1.08)
0.12
14 (56.0) 14 (56.0)
20 (76.9) 11 (42.3)
0.73 (0.48–1.09) 1.32 (0.75–2.34)
0.13 0.33
Interaction P*
0.01
Values are n and %. *Treatment by time interaction P-value.
598
ª 2014 Royal College of Obstetricians and Gynaecologists
Magnesium sulphate infusion adverse effects
Table 2. Secondary maternal outcomes assessed during treatment Outcome
Cardiac arrest Respiratory arrest Death Any respiratory rate of 15 mmHg Loading infusion ceased for adverse effects Any warmth over body Any arm discomfort Any mouth dryness Any mild nausea Any sleepiness Any sweating Any blurred vision Any palpitations Any headache Any dizziness Any muscle weakness Any respiratory depression*** Any maternal tachycardia***
60-minute loading n = 25 0 0 0 0 1 1 9 13 3 3 2 2 0 0 2 1 1 1 1
(0.0) (0.0) (0.0) (0.0) (4.0) (4.0) (36.0) (52.0) (12.0) (12.0) (8.0) (8.0) (0.0) (0.0) (8.0) (4.0) (4.0) (4.3) (4.3)
20-minute loading n = 26 0 0 0 3 2 2 16 17 8 7 5 4 2 2 1 1 1 0 2
(0.0) (0.0) (0.0) (13.6) (7.7) (7.7) (61.5) (65.4) (30.8) (26.9) (19.2) (15.4) (7.7) (7.7) (3.8) (3.8) (3.8) (0.0) (9.5)
RR (95% CI)
P
Not Estimable Not Estimable Not Estimable Not Estimable* 0.52 (0.05–5.38) 0.52 (0.05–5.38) 0.59 (0.32–1.07) 0.80 (0.50–1.27) 0.39 (0.12–1.31) 0.45 (0.13–1.53) 0.42 (0.09–1.95) 0.52 (0.10–2.59) Not Estimable* Not Estimable* 2.08 (0.20–21.52) 1.04 (0.07–15.74) 1.04 (0.07–15.74) Not Estimable* 0.46 (0.04–4.68)
0.11 0.58 0.58 0.08 0.34 0.13 0.20 0.27 0.42 0.49 0.49 0.54 0.98 0.98 1.00 0.51
Values are n and %, unless stated otherwise. *P-value based on Fisher’s exact test. **n = 23, 60-minute loading; n = 22, 20-minute loading. ***n = 23, 60-minute loading; n = 21 20-minute loading.
baseline. In the 20-minute loading group, two (8%) women experienced a decrease in diastolic blood pressure of >15 mmHg from baseline, and three (14%) women experienced a respiratory rate of
