Background: Ultrasound-guided erector spine plane (ESP) block is widely used in perioperative analgesia for back, chest and abdominal surgery. The extent and distribution of this block remain controversial. This study was performed to assess the analgesia range of an ultrasound-guided ESP block. Methods: This prospective observational volunteer study consisted of 12 healthy volunteers. All volunteers received an erector spinae plane block at the left T5 transverse process using real-time ultrasound guidance. Measured the cutaneous sensory loss area (CSLA) and cutaneous sensory declination area (CSDA) using cold stimulation at different time points after blockade until its disappearance. The CSLA and CSDA were mapped and then calculated. The block range was described by spinous process level and lateral extension. The effective block duration for each volunteer was determined and recorded. Results: The cold sensory loss concentrates at T6-T9. The decline concentrates primarily at T4-T11. The lateral diffusion of block to the left side did not cross the posterior axillary line, and reached the posterior median line on the right. The area of cutaneous sensory loss was (172 ± 57) cm 2 , and the area of cutaneous sensory decline was (414 ± 143) cm 2. The duration of cutaneous sensory decline was (586 ± 28) minutes. Conclusion: Ultrasound-guided erector spine plane block with 20 mL of 0. 5% ropivacaine provided a widespread cutaneous sensory block in the posterior thorax, but did not reach the anterior chest, lateral chest, or abdominal walls. The range of the blockade suggested that the dorsal branch of spinal nerve was blocked.
Canagliflozin is an antidiabetic medicine that inhibits sodium-glucose cotransporter 2 (SGLT2) in proximal tubules. Recently, it was reported to have several noncanonical effects other than SGLT2 inhibiting. However, the effects of canagliflozin on skeletal muscle regeneration remain largely unexplored. Thus, in vivo muscle contractile properties recovery in mice ischemic lower limbs following gliflozins treatment was evaluated. The C2C12 myoblast differentiation after gliflozins treatment was also assessed in vitro. As a result, both in vivo and in vitro data indicate that canagliflozin impairs intrinsic myogenic regeneration, thus hindering ischemic limb muscle contractile properties, fatigue resistance recovery, and tissue regeneration. Mitochondrial structure and activity are both disrupted by canagliflozin in myoblasts. Single-cell RNA sequencing of ischemic tibialis anterior reveals a decrease in leucyl-tRNA synthetase 2 (LARS2) in muscle stem cells attributable to canagliflozin. Further investigation explicates the noncanonical function of LARS2, which plays pivotal roles in regulating myoblast differentiation and muscle regeneration by affecting mitochondrial structure and activity. Enhanced expression of LARS2 restores the differentiation of canagliflozin-treated myoblasts, and accelerates ischemic skeletal muscle regeneration in canagliflozin-treated mice. Our data suggest that canagliflozin directly impairs ischemic skeletal muscle recovery in mice by downregulating LARS2 expression in muscle stem cells, and that LARS2 may be a promising therapeutic target for injured skeletal muscle regeneration.
ObjectiveTo explore whether an ultrasound-guided pudendal nerve block (PNB) could decrease anaesthetic use, thereby shortening the length of the second stage of labour in women undergoing epidural analgesia.DesignProspective, single-centre, randomised, double-blind, controlled trial.SettingAn obstetric centre in a general hospital in China.Participants72 nulliparous women were randomised, and 71 women completed the study.InterventionAn ultrasound-guided bilateral PNB was administered to all study participants; the PNB group were given 0.25% ropivacaine 10 mL, while the control group were given 10 mL saline.Main outcome measureThe primary outcome measure was the duration of the second stage of labour. Secondary outcomes included additional bolus administration, total hourly bupivacaine consumption, difference in thickness between the contracted and relaxed rectus abdominis muscle before (DRAM1) and 30 min after (DRAM2) PNB, urge to defecate, maternal cooperation, preservation of the lower limb motor function, tightness of the perineum, and Numeric Rating Scale (NRS) score for pain.ResultsThe duration of the second stage of labour was shorter in the PNB group than in the control group (difference of 33.8 min (95% CI 15.6 to 52.0), p<0.001). Additional bolus administration and total hourly bupivacaine consumption were lower in the PNB group than in the control group (p<0.001). DRAM2 was greater (p<0.001), rate of parturient women with the urge to defecate was higher (p=0.014), maternal cooperation was superior (p=0.002), and lower limb motor function preservation was greater (p=0.004) in the PNB group relative to the control group. Tightness of the perineum was eliminated from the results due to the inconsistent application of the criteria by the nursing staff. There was no significant difference in NRS scores between the groups.ConclusionsNulliparous women with epidural analgesia who received an ultrasound-guided bilateral PNB may reduce their need for bupivacaine and consequently shorten the length of the second stage of labour, therein indicating that a bilateral PNB may serve as an additional effective adjunct method of labour analgesia.Trial registration numberChiCTR-IOR-16009121.
Background
To study the respective peripheral and systemic mechanisms of action of dexmedetomidine, as adjuvant to regional anesthesia, we compared dexmedetomidine added to ropivacaine for mid-forearm nerve blocks, to either systemic-only dexmedetomidine, and to a control with no dexmedetomidine.
Methods
Sixty patients undergoing hand surgery were randomly divided into three groups (n = 20 per group). Each group underwent a triple-nerve (median, radial and ulnar) mid-forearm blocks with 0.75% ropivacaine. In the DexP group, 60 µg of dexmedetomidine were added to the anesthetic mixture, while in the DexIV group, they were intravenously infused. Normal saline as a placebo was used, either as adjuvant, or intravenously. All patients underwent also a supraclavicular block with 1.5% lidocaine for tourniquet pain. The main outcomes were the duration of analgesia and the duration of sensory blockade separately for each nerve termination of the upper limb, and the duration of motor blockade of the upper limb. Tolerance was assessed by blood pressure and heart rate, and the report of adverse events.
Results
Duration of analgesia was longer in the DexP group, in comparison to the two other groups (P < 0.001), while it was similar in the DexIV and the control group. For cutaneous territories targeted by the three mid-forearm blocks, the between-group differences behaved similarly. For the other cutaneous territories (musculocutaneous and posterior brachial cutaneous nerves), duration of sensory blockade was shorter in the control group than in the two dexmedetomidine groups. For duration of motor blockade, the between-group differences behaved similarly. Both blood pressure and heart rate were reduced in the DexP and the DexIV groups, compared to the control.
Conclusions
Dexmedetomidine used as an adjuvant to regional anesthesia may act mostly though a perineural mechanism, especially for the sensory aspects of anesthesia. A systemic action might however explain other clinical effects.
Trial registration
ChiCTR-IOR-17011149, date of registration: 16/04/2017
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