Labour analgesia: update and literature review.

Pain relief is an important component of modern obstetric care and can be produced by neuraxial, systemic, or inhalational analgesia or various physical techniques. We review the most recent evidence on the efficacy and safety of these techniques. Over the past decade, the availability of safer local anaesthetics, ultra-short acting opioids, combined spinal-epidural needles, patient-controlled analgesic devices, and ultrasound have revolutionised obstetric regional analgesia. Recent meta-analyses have supported epidural analgesia as the most efficacious technique, as it leads to higher maternal satisfaction and good maternal and fetal safety profiles. We examine the controversies and myths concerning the initiation, maintenance, and discontinuation of epidural analgesia. Recent evidence will also be reviewed to address concerns about the effects of epidural analgesia on the rates of instrumental and operative delivery, lower back pain, and breastfeeding. New developments in labour analgesia are also discussed.

Pharmacokinetic and pharmacodynamic study of intranasal and intravenous dexmedetomidine.

BACKGROUND: Intranasal dexmedetomidine produces safe, effective sedation in children and adults. It may be administered by drops from a syringe or by nasal mucosal atomisation (MAD NasalTM). METHODS: This prospective, three-period, crossover, double-blind study compared the pharmacokinetic (PK) and pharmacodynamic (PD) profile of i.v. administration with these two different modes of administration. In each session each subject received 1 µg kg-1 dexmedetomidine, either i.v., intranasal with the atomiser or intranasal by drops. Dexmedetomidine plasma concentration and Ramsay sedation score were used for PK/PD modelling by NONMEM. RESULTS: The i.v. route had a significantly faster onset (15 min, 95% CI 15-20 min) compared to intranasal routes by atomiser (47.5 min, 95% CI 25-135 min), and by drops (60 min, 95%CI 30-75 min), (P<0.001). There was no significant difference in sedation duration across the three treatment groups (P=0.88) nor in the median onset time between the two modes of intranasal administration (P=0.94). A 2-compartment disposition model, with transit intranasal absorption and clearance driven by cardiac output using the well-stirred liver model, was the final PK model. Intranasal bioavailability was estimated to be 40.6% (95% CI 34.7-54.4%) and 40.7% (95% CI 36.5-53.2%) for atomisation and drops respectively. Sedation score was modelled via a sigmoidal Emax model driven by an effect compartment. The effect compartment had an equilibration half time 3.3 (95% CI 1.8-4.7) min-1, and the EC50 was estimated to be 903 (95% CI 450-2344) pg ml-1. CONCLUSIONS: There is no difference in bioavailability with atomisation or nasal drops. A similar degree of sedation can be achieved by either method. CLINICAL TRIAL REGISTRATION: HKUCTR-1617.

A randomised controlled trial of oral chloral hydrate vs. intranasal dexmedetomidine before computerised tomography in children.

Chloral hydrate is commonly used to sedate children for painless procedures. Children may recover more quickly after sedation with dexmedetomidine, which has a shorter half-life. We randomly allocated 196 children to chloral hydrate syrup 50 mg.kg-1 and intranasal saline spray, or placebo syrup and intranasal dexmedetomidine spray 3 µg.kg-1 , 30 min before computerised tomography studies. More children resisted or cried after drinking chloral hydrate syrup than placebo syrup, 72 of 107 (67%) vs. 42 of 87 (48%), p = 0.009, but there was no difference after intranasal saline vs. dexmedetomidine, 49 of 107 (46%) vs. 40 of 87 (46%), p = 0.98. Sedation was satisfactory in 81 of 107 (76%) children after chloral hydrate and 64 of 87 (74%) children after dexmedetomidine, p = 0.74. Of the 173 children followed up for at least 4 h after discharge, 38 of 97 (39%) had recovered normal function after chloral hydrate and 32 of 76 (42%) after dexmedetomidine, p = 0.76. Six children vomited after chloral hydrate syrup and placebo spray vs. none after placebo syrup and dexmedetomidine spray, p = 0.03.

Efficacy of birth ball exercises on labour pain management.

OBJECTIVES: To evaluate the efficacy of a birth ball exercise programme conducted by physiotherapists on pain relief, psychological care, and facilitation of the labour process at a labour ward in a regional hospital. DESIGN: Case series with before-after comparisons. SETTING: Kwong Wah Hospital, Hong Kong. PARTICIPANTS: Chinese women admitted to the labour ward for spontaneous vaginal delivery between April and August 2012 were recruited. Physiotherapists taught birth ball exercises in groups or individually for 30 minutes. Labour pain intensity, back pain intensity, frequency of labour pain, stress and anxiety levels, and subjective pressure level over the lower abdomen were captured before and after birth ball exercises. Most of the parameters were measured using self-reported visual analogue scales. After the exercise session, physiotherapists measured the women's satisfaction level. Midwives recorded pethidine usage. RESULTS: A total of 203 pregnant women participated in this programme; 181 were in the latent phase group, whereas 22 were categorised into the no-labour-pain group. In both groups, there were statistically and clinically significant differences in back pain level, stress and anxiety levels, as well as pressure level over the lower abdomen before and after the exercise (P<0.05). In the latent phase group, significant decreases in labour pain and frequency of labour pain were demonstrated. Mean satisfaction scores were high, with visual analogue scale scores higher than 8.2 in both groups. Pethidine usage showed a further decreasing trend (6.4%) compared with the past 2 years. CONCLUSION: Birth ball exercise could be an alternative means of relieving back pain and labour pain in the labour ward, and could decrease pethidine consumption in labouring women.