Anterior Quadratus Lumborum block area comparison in the three different volumes of Ropivacaine: a double-blind, randomized controlled trial in healthy volunteers.

BACKGROUND: In abdominal surgery, ultrasound-guided anterior quadratus lumborum blocks (QLB) are performed to induce analgesia. However, no study reported suitable volumes of the anterior QLB for the different postoperative analgesia regions. Therefore, this prospective randomized controlled study assessed the dermatomal spread and analgesic effects of the three different volumes of a local anesthetic for anterior QLB. METHODS: Ultrasound-guided anterior QLB was performed at the L2 level on 30 healthy volunteers. The volunteers were randomized to receive 20 ml (n = 10), 30 ml (n = 10), and 40 mL (n = 10) of 0.375% ropivacaine. The cutaneous sensory blocked area (CSBA), the number of block dermatomes, and the block duration time were measured by determining the extent of the cold sensation. RESULTS: The CSBA was significantly larger in the 40 ml group than in the 30 (P = 0.001; 1350.6 ± 234.4 vs. 1009.5 ± 151.6 cm2) and 20 ml groups (P < 0.001; 1350.6 ± 234.4 vs. 808.1 ± 120.5 cm2). Similarly, the number of blocked dermatomes was significantly higher in the 40 ml group than in the 30- and 20-ml groups. However, no significant difference was observed in block duration among the groups. CONCLUSIONS: No difference was observed in block duration with the various volumes of 0.375% ropivacaine. However, the larger volume for anterior QLB contributed to a larger area of cutaneous sensory blockade. Appropriate volumes in anterior QLB can create suitable postoperative analgesia levels for the different operative sites. TRIAL REGISTRATION: The study was registered in the Chinese Clinical Trial Registration Center on www.chictr.org.cn on 27th April 2018 (registration number: ChiCTR-IOR-17010853).

Transmuscular quadratus lumborum block versus oblique subcostal transversus abdominis plane block for analgesia in laparoscopic hysterectomy: a randomised single-blind trial.

OBJECTIVE: The transmuscular quadratus lumborum (TQL) block and the oblique subcostal transversus abdominis plane (OSTAP) block both contribute to multimodal analgesia after laparoscopic surgery. The objective of this study was to compare the analgesic effects of the TQL block versus OSTAP block after laparoscopic hysterectomy. DESIGN: Prospective single-centre randomised single-blind trial. SETTING: University-affiliated hospital. PARTICIPANTS: Patients aged between 18 and 65 years scheduled for laparoscopic hysterectomy. INTERVENTIONS: Patients were randomised into two groups (1:1 ratio) and received bilateral TQL block or bilateral OSTAP block with 0.375% ropivacaine 20 mL on each side before surgery. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure was the cumulative morphine dose in the first 24 hours. The secondary outcome measures were the morphine consumption at each time interval after surgery, the time from the end of surgery to the first need for morphine, the Numerical Rating Scale (NRS) scores for visceral and incisional pain intensity, and the incidence of adverse events. RESULTS: The cumulative morphine dose was significantly lower in the TQL group than in the OSTAP group (17.2 (12.5) vs 26.1 (13.3) mg, p=0.010). Compared with the OSTAP group, the morphine doses from 6 to 12, 12 to 18, and 18 to 24 hours were significantly lower, the time of first need for morphine was significantly longer and the NRS scores for visceral pain intensity were significantly lower in the TQL group. CONCLUSION: Compared with the OSTAP block, the TQL block reduced morphine consumption and provided better visceral pain relief with a longer duration of effect after laparoscopic hysterectomy. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry (ChiCTR1800017995); pre-results.

Comparison of ED95 of Butorphanol and Sufentanil for gastrointestinal endoscopy sedation: a randomized controlled trial.

BACKGROUND: Butorphanol, a synthetic opioid partial agonist analgesic, has been widely used to control perioperative pain. However, the ideal dose and availability of butorphanol for gastrointestinal (GI) endoscopy are not well known. The aim of this study was to evaluated the 95% effective dose (ED95) of butorphanol and sufentanil in GI endoscopy and compared their clinical efficacy, especially regarding the recovery time. METHODS: The study was divided into two parts. For the first part, voluntary patients who needed GI endoscopy anesthesia were recruited to measure the ED95 of butorphanol and sufentanil needed to achieve successful sedation before GI endoscopy using the sequential method (the Dixon up-and-down method). The second part was a double-blind, randomized study. Two hundred cases of painless GI endoscopy patients were randomly divided into two groups (n = 100), including group B (butorphanol at the ED95 dose) and group S (sufentanil at the ED95 dose). Propofol was infused intravenously as the sedative in both groups. The recovery time, visual analogue scale (VAS) score, hand grip strength, fatigue severity scores, incidence of nausea and vomiting, and incidence of dizziness were recorded. RESULTS: The ED95 of butorphanol for painless GI endoscopy was 9.07 µg/kg (95% confidence interval: 7.81-19.66 µg/kg). The ED95 of sufentanil was 0.1 µg/kg (95% CI, 0.079-0.422 µg/kg). Both butorphanol and sufentanil provided a good analgesic effect for GI endoscopy. However, the recovery time for butorphanol was significantly shorter than that for sufentanil (P < 0.05, group B vs. group S:21.26 ± 7.70 vs. 24.03 ± 7.80 min). CONCLUSIONS: Butorphanol at 9.07 µg/kg was more effective than sufentanil for GI endoscopy sedation and notably reduced the recovery time. TRIAL REGISTRATION: Chinese Clinical Trail Registry (Registration number # ChiCTR1900022780; Date of Registration on April 25rd, 2019).

Dexmedetomidine enhances tolerance to bupivacaine cardiotoxicity in the isolated rat hearts: alpha 2 adrenoceptors were not involved.

BACKGROUND: Dexmedetomidine was proved to mitigate bupivacaine-induced cardiotoxicity but mechanism of this ability is still unclear. This study was designed to investigate the direct effects of dexmedetomidine on cardiotoxicity induced by bupivacaine on Langendorff rat heart preparation and the role of alpha 2 adrenoceptors in this process was explored. METHODS: Hearts of rat were isolated, mounted on a Langendorff system. Five experimental groups were assessed after 10 min Krebs-Henseleit buffer (KHB) infusions as follow: (1) Group Con, only KHB was perfused; (2) Group Dex, KHB was perfused for 5 min, then dexmedetomidine (10 nmol/L) was added; (3) Group Bupi, KHB was perfused for 25 min, then bupivacaine (50 µmol/L) was added; (4) Group Bupi + Dex, KHB was perfused for 5 min, then the dexmedetomidine (10 nmol/L) was added for 20 min, at last a mixture of KHB + dexmedetomidine + bupivacaine were perfused; (5) Group Bupi + Dex + Yoh, a combination of KHB + yohimbine (alpha 2 adrenoceptor antagonists, 1 µmol/L) was perfusion for 5 min, then dexmedetomidine (10 nmol/L) was added for 20 min, at last a mixture of KHB + yohimbine + dexmedetomidine + bupivacaine was perfused. The experimental perfusion was maintained for 35 min in group Con and group Dex, and the experimental perfusion was sustained until asystole in the other three groups. RESULTS: Compared with group Bupi, dexmedetomidine significantly increased the time to first arrhythmia (P <  0.001) and time to asystole (P <  0.001) in group Bupi + Dex. In addition, dexmedetomidine also significantly increased the time to 25, 50 and 75% reductions in heart rate (P <  0.001) and the time to 25, 50 and 75% reductions in rate-pressure product (P <  0.001) in group Bupi + Dex. Dexmedetomidine increased the cardiac tissue bupivacaine content when asystole (Bupi + Dex vs. Bupi, 58.5 ± 6.3 vs. 46.8 ± 5.6 nmol/g, P = 0.003). The benefit of dexmedetomidine on bupivacaine-induced cardiotoxicity were not eliminated by yohimbine. CONCLUSIONS: Dexmedetomidine could delay the occurrence of bupivacaine-induced arrhythmia and asystole in the isolated rat hearts, but the alpha 2 adrenoceptors were not involved in this process.

Supplement of levosimendan to epinephrine improves initial resuscitation outcomes from asphyxial cardiac arrest.

BACKGROUND: Levosimendan exerted favorable effects on the initial outcome in the treatment of ventricular fibrillation cardiac arrest. This study investigated the efficacy of levosimendan in the treatment of asphyxia-induced cardiac arrest in rats. METHODS: Animals underwent asphyxial cardiac arrest/cardiopulmonary resuscitation, randomized to three treatment groups: epinephrine (10 µg/kg) supplemented with levosimendan (bolus 12 µg/kg and infusion for 1 h, EL group); epinephrine only (10 µg/kg, E group), or levosimendan only (bolus 12 µg/kg and infusion for 1 h, L group). The resuscitation success rate, wet-to-dry ratio of lung, and rate of alveolar and blood gas analysis were recorded. RESULTS: 10 rats in the EL group, 8 in the E group, and 2 in the L group showed an initial return of spontaneous circulation (P < 0.001); among them, 10, 4, and 2 rats survived at the end of a 60-min observation period from each group, respectively (P = 0.001). The coronary perfusion pressure in the EL group was higher than that of either the E or L group (P < 0.05). The lung wet-to-dry weight ratio and rate of damaged alveoli were lower in the EL group than the E group (P < 0.05). CONCLUSIONS: In the early stage of resuscitation for asphyxia-induced cardiac arrest in rats, levosimendan supplemented with epinephrine can significantly increase coronary perfusion pressure, reduce lung injury, and ultimately enhance the survival rate.

Giving Priority to Lipid Administration Can Reduce Lung Injury Caused by Epinephrine in Bupivacaine-Induced Cardiac Depression.

BACKGROUND AND OBJECTIVES: Epinephrine is usually administered in concert with a lipid emulsion during local anesthetic toxicity. However, the timing and role of epinephrine administration in combination with a lipid emulsion remain unclear. Specifically, the temporal association of epinephrine and lipid emulsion administration with related changes in pulmonary vascular pressures that may lead to pulmonary edema and hemorrhage needs to be determined. METHODS: This study consisted of 2 parts, experiments A and B. In experiment A, 24 adult male Sprague-Dawley rats were randomly divided into 3 groups (n = 8) to receive 1 of 3 treatments. All rats were anesthetized with an intraperitoneal injection of chloral hydrate, and anesthesia was maintained by sevoflurane. Each treatment group was initially given an infusion of bupivacaine (15 mg/kg) in order to produce cardiac depression. Group 1 (A-LEN) received a 30% lipid infusion (3 mL/kg) followed by a rapid epinephrine bolus (10 µg/kg), which was then followed by a normal saline infusion (3 mL/kg). Group 2 (A-NEL) first received a normal saline infusion (3 mL/kg) followed by a rapid epinephrine bolus, which was then followed by a 30% lipid emulsion. Group 3 (A-NEN, considered a control group) first received a normal saline infusion (3 mL/kg) followed by a rapid epinephrine bolus (10 µg/kg), which was then followed by another normal saline infusion (3 mL/kg). Lipid and normal saline infusions were administered over 1 minute, whereas epinephrine was injected rapidly. The continuous monitoring of blood pressure, heart rate, pulmonary arterial pressure, and pulmonary venous pressure occurred for 30 minutes. After the 30-minute monitoring period, lung tissue was sampled, and bronchoalveolar lavage fluid was collected. In experiment B, the experimental model and resuscitation protocol were similar to experiment A (B-LEN and B-NEL groups). In this arm of the experiment, bupivacaine concentrations of cardiac tissue were determined after the second minute of normal saline infusion. RESULTS: The A-LEN group produced the best rate pressure product when compared with the A-NEL or A-NEN group (P = 0.045, P = 0.011, respectively). In regard to pulmonary venous pressure, the A-LEN group was lower than the A-NEL or A-NEN group (P = 0.031, P = 0.006, respectively). Animals in the A-NEL and A-NEN groups rapidly developed pulmonary edema after infusion of epinephrine. The wet-to-dry ratio of the lungs in the A-LEN group was lower than that of the lungs in the A-NEL group (P = 0.024).The lung permeability index of the A-LEN group was lower than that of the A-NEL group (P = 0.011). In experiment B, concentrations of bupivacaine in cardiac tissue and plasma of the B-LEN group were lower than those of the B-NEL group (P = 0.001, P = 0.03, respectively). CONCLUSIONS: Giving priority to the administration of a lipid emulsion before the administration of epinephrine can reduce lung injury in bupivacaine-induced cardiac depression in rats.