Evaluation of Two Different Doses of Pre-Emptive Intravenous Magnesium Sulphate as Post- Operative Adjunct Analgesia after Gynaecological Surgery
Analgesic Effects of Magnesium Sulphate
Abstract
This study compared the analgesic effects of pre-emptive intravenous magnesium sulphate of different dosages in patients undergoing lower abdominal gynaecological surgery. Fifty-six patients with Body Mass Index (BMI) <35 kg/m2 who underwent lower abdominal gynaecological surgery were randomly recruited into two groups. Group I received one ampoule (2.47 g) of magnesium sulphate and Group II received 50 mg/kg magnesium sulphate (based on body weight), pre-operatively. Pain score and patient controlled analgesia (PCA) morphine requirement were compared at 30 minutes, 12 hours and 24 hours post-operatively. The pain score was comparable at all intervals between the two groups (30 minutes, p = 0.450; 12 hours, p = 0.402; and 24 hours, p = 1.000). Post-operative PCA morphine requirement was not statistically significant between the two groups at 30 minutes, 12 hours, and 24 hours (2.7 vs 2.4 mg, p = 0.545; 12.5 vs 9.8 mg, p = 0.154; 7.7 vs 6.4 mg, p = 0.323). The side-effects of magnesium sulphate on blood pressure, heart rate and sedation were not statistically significant between the two groups. In conclusion, the analgesic effects of pre-emptively administered intravenous MgSO4 of 2.47 g (one ampule) was comparable to 50 mg/kg in patients with BMI less than 35 kg/m2 following lower abdominal gynaecological surgery under general anaesthesia with negligible side effects.
Keywords :
gynecologic surgical procedure,
magnesium sulphate,
morphine usage,
post-operative pain,
pre-emptive analgesia,
Abstrak
Kajian ini dilaksanakan untuk membandingkan keberkesanan analgesia pre-emptif intravena magnesium sulfat menggunakan dos yang berbeza terhadap kesan pengawalan kesakitan berikutan pembedahan ginekologi. Seramai 56 orang pesakit dengan Indeks Jisim Badan (BMI) <35 kg/m2 yang menjalani pembedahan ginekologi direkrut kepada dua kumpulan secara rawak. Kumpulan I menerima magnesium sulfat satu ampul 2.47 g dan Kumpulan II menerima magnesium sulfat 50 mg/kg (berdasarkan berat badan) sebaik sahaja sebelum pembedahan. Tahap kesakitan dan penggunaan analgesia kawalan pesakit (PCA) morfin dibandingkan pada 30 minit, 12 jam, dan 24 jam selepas pembedahan. Tidak terdapat perbezaan tahap kesakitan yang ketara antara dua kumpulan (30 minit, p = 0.450; 12 jam, p = 0.402; and 24 jam, p = 1.000). Penggunaan PCA morfin antara dua kumpulan pada 30 minit, 12 jam, dan 24 jam selepas pembedahan juga tidak menunjukkan perbezaan yang nyata (2.7 vs 2.4 mg, p = 0.545; 12.5 vs 9.8 mg, p = 0.154; 7.7 vs 6.4 mg, p = 0.323). Kesan sampingan magnesium sulfat terhadap tekanan darah, denyutan jantung dan tahap kesedaran juga tidak menunjukkan perbezaan yang nyata di antara kedua-dua kumpulan. Kesimpulannya, kawalan kesakitan berikutan pembedahan ginekologi dengan bius umum di kalangan pesakit yang menerima samada suntikan magnesium sulfat satu ampul (2.47 g) atau 50 mg/kg secara pre-emptif untuk pesakit-pesakit BMI <35 kg/m2 adalah setara dengan kesan sampingan yang minima.
Kata Kunci :
analgesia pre-emptif,
magnesium sulfat,
pembedahan ginekologi,
penggunaan morfin,
tahap kesakitan,
Correspondance Address
Professor Dr. Joanna Ooi Su Min. Department of Anaesthesiology and Intensive Care, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia. Tel: +6019-3207265 Email: ooi.joanna@yahoo.com
