Purpose Quadratus lumborum block (QLB) is shown to be effective on analgesia following cesarean section. This study aimed to compare the effects of three practical QLB approaches and classic epidural analgesia (EA) for cesarean section under spinal anesthesia. Patients and methods Parturients undergoing elective cesarean section were randomized as group 1 (QLB type 2), group 2 (QLB type 3), group 3 (QLB type 2+3) and group 4 (EA). The block was performed at the end of the operation, and the epidural group was given a single epidural bolus. All subjects were provided with intravenous patient-controlled analgesia under identical settings. In addition, the postoperative pain severity was assessed by the VAS, which together with the morphine consumption at specific time intervals, was recorded within 48 hrs after surgery. Data were collected from December 2017 to June 2018. Results A total of 94 parturients had completed the study. At almost all postoperative time points, the VAS scores at rest and with movement in QLB type 2+3 group were lower than those in QLB type 2 or 3 group. The mean additional morphine consumption in QLB type 2+3 group (2.7 mg) was lower than that in QLB type 2 or 3 group (6.1 mg and 5.7 mg, respectively) within 48 h after surgery ( P <0.001). Besides, the total morphine consumption in EA group (1.3 mg) was lower than that in any other QLB group ( P <0.001). Conclusions The analgesic effect of QLB is highly dependent on the injection position of local anesthetic. Besides, the ultrasound-guided QLB type 2+3 can provide superior analgesic effect following cesarean section to that of QLB type 2 or 3 block. However, it remains to be further validated about whether the combination of QLB type 2 and 3 is the best approach.

BackgroundFemoral nerve block (FNB) has been considered as an excellent analgesic modality in total knee arthroplasty (TKA) pain control. However, relatively high concentration of ropivacaine could lead to quadriceps muscle weakness and increase the risk of postoperative falls.ObjectiveThis double-blinded randomized controlled study was designed to investigate the effect of a combination of dexmedetomidine with a lower concentration of ropivacaine on quadriceps muscle strength and analgesic effect in FNB.MethodsA total of 90 patients scheduled for TKA were randomized to receive continuous FNB postoperatively using 0.2% ropivacaine (H group), 0.1% ropivacaine (L group) or 0.1% ropivacaine combined with 2 μg/kg dexmedetomidine (LD group). Meanwhile, intravenous patient-controlled analgesia with morphine was administered to patients. The primary endpoint was the strength of quadriceps muscle evaluated by manual muscle testing (MMT) and Timed Up and Go test (TUG). The secondary endpoint was the pain scores and morphine consumption among different groups.ResultsFor MMT, LD group showed higher quadriceps muscle strength than the other two groups (P<0.05) at 12 hrs postoperatively. TUG test was conducted to measure the walking ability, and showed that scores were significantly better in LD group than those in H group and L group (P<0.05) at 24 and 48 hrs postoperatively. There was no significant difference between H and LD group in the numeric rating scales (NRS) scores both at rest and at 45° flexion. The total morphine consumption in L group was significantly higher than in H or LD group (P<0.001).ConclusionCollectively, the addition of dexmedetomidine 2 μg/kg to 0.1% ropivacaine preoperatively would preserve quadriceps muscle strength with satisfactory analgesia in patients undergoing TKA. (This study was registered at ClinicalTrials.gov, identifier NCT03658421).

The increasing usage of general anesthetics on young children and infants has drawn extensive attention to the effects of these drugs on cognitive function later in life. Recent animal studies have revealed improvement in hippocampus-dependent performance after lower concentrations of sevoflurane exposure. However, the long-term effects of low-dose sevoflurane on the developing brain remain elusive. On postnatal day (P) 7, rats were treated with 1.2% sevoflurane (1.2% sevo group), 2.4% sevoflurane (2.4% sevo group), and air control (C group) for 6 h. On P35-40, rats' hippocampus-dependent learning and memory was tested using the Morris water maze. Cognition-related and synapse-related proteins in the hippocampus were measured using Western blotting on P35. On the same day, neurogenesis and synapse ultrastructure were evaluated using immunofluorescence and transmission electron microscopy (TEM). On P35, the rats neonatally exposed to 1.2% sevoflurane showed better behavioral results than control rats, but not in the 2.4% sevo group. Exposure to 1.2% sevoflurane increased the number of 5'-bromo-2-deoxyuridine (BrdU)-positive cells in the dentate gyrus and improved both synaptic number and ultrastructure in the hippocampus. The expression levels of BDNF, TrkB, postsynaptic density (PSD)-95, and synaptophysin in the hippocampus were also increased in the 1.2% sevo group. In contrast, no significant changes in neurogenesis or synaptic plasticity were observed between the C group and the 2.4% sevo group on P35. These results showed that exposure of the developing brain to a low concentration of sevoflurane for 6 h could promote spatial learning and memory function, along with increased hippocampal neurogenesis and synaptic plasticity, in later life.

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