Intranasal dexmedetomidine induced satisfactory rescue sedation in 1- to 6-month-old infants during MRI study, and appears to cause sedation in a dose-dependent manner.

Background The median effective dose (ED50) of intranasal dexmedetomidine after failed chloral hydrate sedation has not been described for children. This study aims to determine the ED50 of intranasal dexmedetomidine for rescue sedation in children aged 1 to 36 months, who were inadequately sedated by chloral hydrate administration during magnetic resonance imaging (MRI). Methods This study was performed on 120 children, who were 1 to 36 months old and underwent MRI scanning. Intranasal dexmedetomidine was administered as a rescue sedative to children not adequately sedated after the initial oral dose of chloral hydrate (50 mg/kg). Children were stratified into four age groups. ED50 values were estimated from the up-and-down method of Dixon and Massey and probit regression. Other variables included induction time, time to wake up, vital signs, oxygen saturation, MRI scanning time, and recovery characteristics. Results ED50 of intranasal dexmedetomidine for rescue sedation was 0.4 μg/kg (95% CI, 0.34 to 0.50) in children aged 1 to 6 months, 0.5 μg/kg (95% CI, 0.48 to 0.56) in children aged 7 to 12 months, 0.9 μg/kg (95% CI, 0.83 to 0.89) in children aged 13 to 24 months, and 1.0 μg/kg (95% CI, 0.94 to 1.07) in children aged 25 to 36 months. There were no significant differences in sedation induction time or time to wake up between the different age groups. Additionally, no significant adverse hemodynamic or hypoxemic effects were noted. Conclusions The authors determined the ED50 for rescue sedation using intranasal dexmedetomidine after failed chloral hydrate sedation in children. It was found that ED50 increases with advancing age during the first 3 yr of life.

Background This study is to investigate if non‐intubated anaesthesia combined with paravertebral nerve block (PVNB) can enhance recovery in children undergoing video‐assisted thoracic surgery (VATS). Methods A randomized controlled trial including 60 patients aged 3 to 8 years old who underwent elective VATS was performed. They were randomly assigned to receive non‐intubated anaesthesia combined with PVNB or general anaesthesia with tracheal intubation (1:1 ratio). The primary outcome was the length of postoperative in‐hospital stay. The secondary outcomes included emergence time, the incidence of emergence delirium, time to first feeding, time to first out‐of‐bed activity, pain score and in‐hospital complications. Results The non‐intubated group had shorter postoperative in‐hospital stay than the control group (4 days [IQR, 4‐6] vs 5 days [IQR, 5‐8], 95% CI 0‐2; P = .013). When compared to the control group, the incidence of emergence delirium (odds ratio [OR] 3.39, 95% CI 1.01‐11.41; P = .043), emergence time, duration in the PACU, time to first eating food, first out‐of‐bed activity, pain score and consumption of sufentanil (at 6 and 12 hours after surgery) were decreased in the intervention group. In contrast, the incidence of airway complications was higher in the control than the intervention group (27.6% vs 6.9%, P = .037). There was no statistical significance in the occurrence of PONV, pneumothorax and other complications between the two groups. Conclusions Non‐intubated anaesthesia combined with PVNB enhances recovery in paediatric patients for video‐assisted thoracic surgery although further multi‐centre study is needed.

BackgroundThe effect of body mass index (BMI) on the spread of spinal anesthesia is not completely clear. The aim of this study was to determine the dose requirements of ropivacaine and the incidence of hypotension in pregnant women with different BMIs during cesarean delivery.Material/MethodsIn this double-blind study, 405 women undergoing elective cesarean delivery were allocated to group S (BMI <25), group M (25 ≤BMI <30), or group L (BMI ≥30). Women in each group were further assigned to receive 7, 8, 9, 10, 11, 12, 13, 14, or 15 mg of spinal ropivacaine.ResultsThe ED50 and ED95 values of ropivacaine were 9.487 mg and 13.239 mg in Group S, 9.984 mg and 13.737 mg in Group M, and 9.067 mg and 12.819 mg in Group L. There were no significant differences among the 3 groups (p=0.915). Group L had a higher incidence of hypotension and a greater change in MAP after spinal anesthesia compared to the other 2 groups, and also required more doses of ephedrine than the other 2 groups when a dose of 15 mg ropivacaine was used. The incidence of hypotension had a positive correlation with the dose of ropivacaine (OR=1.453, p<0.001) and gestational age (OR=1.894, p<0.001).ConclusionsSpinal ropivacaine dose requirements were similar in the normal BMI range. However, higher doses of spinal ropivacaine were associated with an increased incidence and severity of hypotension in obese patients compared with that in non-obese patients.