Effect of subcutaneous sterile water injections vs normal saline injections for relief of continuous back pain in Labour at Kenyatta National Hospital. a randomised, double blind, placebo controlled trial

Abstract

Background: Sterile Water Injections (SWI) are ideal for managing continuous labour back pain in the active stage. However, their effectiveness on African parturient and acceptability in African settings is poorly understood. To fill this gap a double blind, placebo controlled, randomised control trial (RCT) was done in an urban hospital setting in Nairobi, Kenya. Objectives: We evaluated the analgesic effect of SWI on continuous back pain in labour among parturients in the active stage of labour. It also determined the effect of SWI for continuous labor back pains on maternal and neonatal outcomes and its acceptability in the African setting. Methodology: Parturients confirmed to be admitted in the active stage of labour were recruited and randomly allocated to study groups. A total of 60 parturients (30 in the intervention group and 30 in the control group) were recruited after provision of an informed consent. Parturients in the intervention arm received 0.5ml injections of subcutaneous SWI injections at the four points bordering the Michaelis Rhomboid on the sacral region of the back. The procedure was the same for parturients in the control arm, but using 0.5 ml of 0.9% normal saline solution. Socio-demographic data were recorded. Baseline data on pain perception of parturient was also recorded using a visual analogue scale (VAS) before the administration of injections and 10, 30, 60, 90, and 120 minutes after injections. After delivery, data on adverse maternal and neonatal outcomes were recorded. Mother to baby interaction was evaluated by measuring the time the mother initiated breastfeeding after delivery. The satisfaction of parturients with treatments and whether they might use treatments in future deliveries or recommend them to other parturients was documented. To analyze data, the Statistical Package for Social Scientists (SPSS) software was used. Continuous data were tested for normality using the Shapiro Wilks test and frequency distributions computed. The categorical data were visualized in tables as percentages and mean differences for VAS scores between study groups determined at 10, 30, 60, 90, and 120 minutes using the t test. The t test and Chi-square test were used to compare occurrence of maternal and neonatal outcomes between groups and satisfaction of mothers with SWI or NSI. Statistical significance were interpreted by analysis of P values at the 95% level of confidence (p<0.05). Results: Demographic and reproductive characteristics of parturients were comparable in study groups. At baseline, pain perception, as interpreted by self-reported VAS scores, were similar between the SWI (90 cm) and normal saline (87 cm) groups (P=0.102). However, VAS scores at 10 minutes, 30 minutes, 60 minutes, 90 minutes, and 120 minutes were significantly different with women who received SWI for the management of labour back pair reporting significantly less pain perception. SWI did not influence the occurrence of adverse maternal and neonatal outcomes and was viewed as a good mode of pain relief, with 73% more patients in SWI group reporting to be very satisfied with and highly likely to reuse SWI during pregnancies (P<0.001) Conclusion: We have demonstrated the suitability of using SWI for management of continuous labour back pain in African parturient. Administered on the Michaelis Rhomboid on the sacral region of the back, it induces fast and lasting pain relief without adverse pregnancy outcomes.