Size control of ropivacaine nano/micro-particles by soft-coating with peptide nanosheets for long-acting analgesia.

Rationale: To meet the need of long-acting analgesia in postoperative pain management, slow-releasing formulations of local anesthetics (LAs) have been extensively investigated. However, challenges still remain in obtaining such formulations in a facile and cost-effective way, and a mechanism for controlling the release rate to achieve an optimal duration is still missing. Methods: In this study, nanosheets formed by a self-assembling peptide were used to encapsulate ropivacaine in a soft-coating manner. By adjusting the ratio between the peptide and ropivacaine, ropivacaine particles with different size were prepared. Releasing profile of particles with different size were studied in vitro and in vivo. The influence of particle size and ropivacaine concentration on effective duration and toxicity were evaluated in rat models. Results: Our results showed that drug release rate became slower as the particle size increased, with particles of medium size (2.96 ± 0.04 µm) exhibiting a moderate release rate and generating an optimal anesthetic duration. Based on this size, formulations at different ropivacaine concentrations generated anesthetic effect with different durations in rat sciatic nerve block model, with the 6% formulation generated anesthetic duration of over 35 h. Long-acting analgesia up to 48 h of this formulation was also confirmed in a rat total knee arthroplasty model. Conclusion: This study provided a facile strategy to prepare LA particles of different size and revealed the relationship between particle size, release rate and anesthetic duration, which provided both technical and theoretical supports for developing long-acting LA formulations with promising clinical application.

Ultrasound-guided intersphincteric space block combined with spinal anesthesia for hemorrhoidectomy: a randomized clinical trial.

BACKGROUND: We aimed to compare the analgesic effects and incidence of urinary retention between ultrasound-guided intersphincteric space block combined with low-dose ropivacaine spinal anesthesia and conventional-dose ropivacaine spinal anesthesia post-hemorrhoidectomy. METHODS: Fifty patients aged 20-65 years who underwent elective hemorrhoidectomy were stochastically assigned to one of two groups. Spinal anesthesia was induced with 8 mg ropivacaine, combined with ultrasound-guided intersphincteric space block in the treatment group. Spinal anesthesia was induced with 12 mg ropivacaine in the control group. The primary outcome was the postoperative pain score, measured using the Visual Analog Scale (VAS) at 4, 8, 12, 24, and 48 hours and at the first defecation postoperatively. Secondary outcomes included urinary retention, extent of anal sphincter relaxation, and the time required to lift the lower limbs out of bed postoperatively. RESULTS: The treatment group showed markedly lower VAS scores than those of the control group at 8, 12, 24, and 48 h, and at the first postoperative defecation time (P<0.05). The incidence of urinary retention was considerably lower in the treatment group than in the control group (24% vs. 52%, P=0.04). No remarkable difference in the degree of anal sphincter relaxation was observed between the two groups (P=0.556). The time taken by the treatment group patients to lift their lower limbs off the bed was much shorter than that in the control group (1.3±0.6 h vs. 3.2±1.2 h, P<0.001). CONCLUSIONS: Ultrasound-guided intersphincteric space block combined with low-dose ropivacaine spinal anesthesia provides good anesthesia and analgesia for hemorrhoidectomy.

Effect of Perineural or Intravenous Betamethasone on Femoral Nerve Block Outcomes in Knee Arthroplasty: A Randomized, Controlled Study.

OBJECTIVES: Despite the use of multimodal analgesia, patients undergoing knee arthroplasty still encounter residual moderate pain. The addition of betamethasone to local anesthetic has been shown to improve postoperative pain. However, it remains uncertain whether the positive effects of perineural or intravenous administration of betamethasone on analgesia outcomes lead to better early mobility and postoperative recovery. METHODS: Between June 2022 and February 2023, a total of 159 patients who were undergoing knee arthroplasty were included in this study. These patients were allocated randomly into three groups: (i) the NS group, received ropivacaine 0.375% and intravenous 3mL 0.9% normal saline; (ii) the PNB group, received ropivacaine 0.375% plus perineural betamethasone (12mg) 3mL and intravenous 3mL 0.9% normal saline; and (iii) the IVB group, received ropivacaine 0.375% and intravenous betamethasone (12mg) 3mL. RESULTS: Both perineural and intravenous administration of betamethasone led to improved median (IQR) numeric rating scale (NRS) scores on the 6-meter walk test, with a score of 1.0 (1.0-2.0) for both groups, compared with 2.0 (1.0-2.0) for the NS group (p = 0.003). Compared to the NS group, both the PNB and IVB groups showed significant reductions in NRS scores at 24 and 36 h after surgery, along with a significant increase in ROM at 24, 36, and 48 h post-operation. Additionally, it exhibited lower levels of cytokine IL-1ß and TNF-α in fluid samples, as well as lower level of HS-CRP in blood samples in the PNB and IVB groups compared to the NS group. CONCLUSION: The administration of perineural and intravenous betamethasone demonstrated an enhanced analgesic effect following knee arthroplasty. Furthermore, it was associated with reduced levels of IL-1ß, TNF-α, and HS-CRP, as well as enhanced knee ROM, which is conducive to early ambulation and postoperative rehabilitation after knee arthroplasty.

Comparative Analysis of Temperature-Responsive Hydrogel (PF 72) for Postoperative Pain After Bimaxillary Surgery: A Retro-spective Study.

Bimaxillary surgery is a painful invasive procedure in plastic surgery. Pain control is typically achieved using intravenous analgesics. We aimed to investigate the efficacy of a novel temperature-responsive hydrogel, PF72, mixed with ropivacaine, as a local pain management solution when applied directly to the surgical site following orthognathic surgery. The study was conducted from October 2022 to July 2023 and included a cohort of 40 candidates for orthognathic surgery, encompassing LeFort I maxillary ostectomy and sagittal split ramus osteotomy. The participants were divided into an Injection group (n = 20), where PF72 was administered at the surgical site before the orthognathic surgery, and a Control group (n = 20), which relied solely on intravenous analgesics. Pain was evaluated at 3, 6, 24, 48, and 72 h after surgery using a numerical rating scale (NRS). The mean NRS scores at 24 h were 6.35 and 4 for the Control and Injection groups, respectively. The mean NRS scores at 72 h were 3.4 and 2.55 for the Control and Injection groups, respectively. Patients who received PF72 experienced less pain than those who received intravenous analgesics. These findings underscore the potential of PF72 as an effective alternative for enhancing pain management in patients undergoing orthognathic surgery.Level of Evidence III Therapeutic study. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Dexamethasone and dexmedetomidine as adjuvants to ropivacaine do not prolong analgesia in wound infiltration for lumbar spinal fusion: a prospective randomized controlled study.

BACKGROUND AND OBJECTIVES: Local anesthetics (LAs) are widely used to infiltrate into surgical wounds for postoperative analgesia. Different adjuvants like dexamethasone and dexmedetomidine, when added to LA agents, could improve and prolong analgesia. The aim of this trial was to evaluate the analgesic efficacy and opioid-sparing properties of dexamethasone and dexmedetomidine when added to ropivacaine for wound infiltration in transforaminal lumbar interbody fusion (TLIF). METHODS: We conducted a controlled study among 68 adult patients undergoing TLIF, which was prospective, randomized and double-blind in nature. The participants were divided into four equal groups at random. Group R was given 150 mg of 1% ropivacaine (15 mL) and 15 mL of normal saline. Group R + DXM received 150 mg of 1% ropivacaine (15 mL) and 10 mg of dexamethasone (15 mL). Group R + DEX received 150 mg of 1% ropivacaine (15 mL) and 1 µg/kg of dexmedetomidine (15 mL). Lastly, group R + DXM + DEX was given 150 mg of 1% ropivacaine (15 mL), 10 mg of dexamethasone and 1 µg/kg of dexmedetomidine (15 mL). The primary focus was on the length of pain relief provided. Additionally, secondary evaluations included the amount of hydromorphone taken after surgery, the numerical rating scale and safety assessments within 48 h after the operation. RESULTS: Based on the p value (P > 0.05), there was no significant variance in the duration of pain relief or the total usage of hydromorphone after surgery across the four groups. Similarly, the numerical rating scale scores at rest and during activity at 6-, 12-, 24- and 48-h post-surgery for all four groups showed no difference (P > 0.05). However, the incidence of delayed anesthesia recovery was slightly higher in group R + DEX and group R + DXM + DEX when compared to group R or group R + DXM. Furthermore, there were no significant differences between the four groups in terms of vomiting, nausea, dizziness or delayed anesthesia recovery. CONCLUSION: For wound infiltration in TLIF, the addition of dexamethasone and dexmedetomidine to ropivacaine did not result in any clinically significant reduction in pain or opioid consumption and could prompt some side effects.

Comparison of Caudal Dexmedetomidine and Midazolam as an Adjuvant to Ropivacaine for Postoperative Pain Relief in Children Undergoing Infra-Umbilical Surgeries: A Randomized Controlled Trial.

BACKGROUND: We explored the analgesic efficacy of two non-opioid adjuvants (midazolam and dexmedetomidine) with ropivacaine in children undergoing infraumbilical surgeries. METHODS: In this parallel group randomized controlled trial, 135 children aged between 2 and 8 years were recruited. Children were randomly allocated to one of three groups: RD received 1 mL/kg of ropivacaine (0.2%) with dexmedetomidine 1 µg/kg, RM received 1 mL/kg of ropivacaine (0.2%) with midazolam 30 µg/kg, and R received 1 mL/kg of ropivacaine (0.2%) with 1 mL normal saline. The primary outcome of the present study was to determine the duration of postoperative analgesia. Secondary outcomes were assessing postoperative face, leg, activity, cry, consolability (FLACC) pain score, rescue analgesics, hemodynamics, sedation scores, and adverse effects. RESULTS: The analgesia duration was significantly prolonged in the RD and RM group (600.0 [480.0-720.0] minutes and 600.0 [480.0-720.0] minutes, respectively) compared to the R group 360.0 (300.0-480.0) minutes (P < 0.001). The FLACC score was comparatively higher in the R group compared to the RD and RM groups postoperatively. Time for the first rescue analgesia was more prolonged in RD and RM groups when compared with the R group. Postoperative sedation was higher in the RM group up to 120 minutes postoperatively compared to the RD and R groups. CONCLUSION: The combination of dexmedetomidine or midazolam with local anesthetics significantly increases the analgesia duration while minimizing adverse effects.

Adductor Canal Block Combined with General Analgesia for Patients with Recurrent Patellar Dislocation Undergoing "3-in-1" Procedure Surgery: A Prospective Randomized Controlled Trial.

OBJECTIVE: Patellar dislocation is a common injury in sports medicine. While surgical treatment is an important option, pain is severe after surgery. This study compared the analgesic effect and early rehabilitation quality between adductor canal block combined with general analgesia (ACB + GA) and single general analgesia (SGA) after recurrent patellar dislocation (RPD) for "3-in-1" procedure surgery. METHODS: From July 2018 to January 2020, a prospective randomized controlled trial was conducted in analgesia management after RPD for "3-in-1" procedure surgery. The 40 patients in the experimental group received ACB (0.3% ropivacaine 30 mL) + GA, while the 38 patients in the control group received SGA. Patients in both groups received "3-in-1" procedure surgery, standardized anesthesia, and analgesia during hospitalization. The outcomes included the visual analog scale (VAS), quadriceps strength, Inpatient Satisfaction Questionnaire (IPSQ), Lysholm scores, and Kujala scores. Total rescue analgesic consumption and adverse events were also recorded. One-way analysis of variance (ANOVA) was used to compare continuous variables between groups and chi-square or Fisher's exact tests were used to compare count data. Nonparametric Kruskal-Wallis H tests evaluated ranked data. RESULTS: No significant differences in resting VAS scores were observed at 8, 12, and 24 h postoperatively. However, the flexion and moving VAS scores of the ACB + GA group were significantly lower than those of the SGA group (p < 0.05). Meanwhile, the first triggering of rescue analgesics was advanced in the SGA group (p < 0.0001), and the dose of opioid analgesics was significantly higher (p < 0.0001). The quadriceps strength of the ACB + GA group was higher than that of the SGA group at 8 h postoperatively. The IPSQ of the ACB + GA group was significantly higher 24 h postoperatively. We observed no significant differences in Lysholm and Kujala scores between the two groups at 3 months after surgery. CONCLUSIONS: Early analgesia management of ACB + GA showed excellent analgesia effectiveness and a positive hospitalization experience for RPD patients undergoing "3-in-1" procedure surgery. Moreover, this management was good for early rehabilitation.

Determination of the Dose-Response Relationship of Epidural Dexmedetomidine Combined with Ropivacaine for Labor Analgesia.

Background: The safety and efficacy of dexmedetomidine for epidural labor analgesia have been reported in numerous literatures, but the optimal dose has not been fully determined. The objective of this study was to determine the dose-response relationship of epidural dexmedetomidine (combined with ropivacaine) for labor analgesia. Methods: A total of 120 full-term laboring parturients requesting epidural labor analgesia were enrolled in the study from July 5, 2020 to September 22, 2021. The parturients were randomly assigned to receive 0, 0.1, 0.2, 0.3, 0.4 or 0.5 µg/mL dexmedetomidine combined with 0.075% ropivacaine epidurally. An effective dose was defined as numerical rating scale (NRS) pain score ≤3 at 30-minutes of epidural drug injection. The dose-response relationship of dexmedetomidine (with ropivacaine) for epidural labor analgesia was performed using probit regression. The median effective dose (ED50) and the 95% effective dose (ED95) values for epidural dexmedetomidine combined with 0.075% ropivacaine with 95% confidence intervals (CIs) were derived by interpolation. Results: The estimated values of ED50 and ED95 with 95% CIs for epidural dexmedetomidine (combined with 0.075% ropivacaine) were 0.085 (0.015 to 0.133) µg/mL and 0.357 (0.287 to 0.493) µg/mL, respectively. No differences were found among groups for sensory block level, number of parturients with Bromage score >0, total dosage of analgesics, cesarean delivery rate, fetal birth weight, Apgar score at 1-minute, Apgar score at 5-minutes and adverse effects. Compared with other groups, group dexmedetomidine 0.5 µg/mL had a longer duration of the first stage of labor. Conclusion: The ED50 and ED95 values of dexmedetomidine for epidural labor analgesia was 0.085 and 0.357 µg/mL under the conditions of this study. Dexmedetomidine is a suitable adjuvant for epidural labor analgesia.

Lipid emulsions attenuate the inhibition of carnitine acylcarnitine translocase induced by toxic doses of local anesthetics in rat cardiomyoblasts.

The aim of this study was to examine the effects of lipid emulsions on carnitine palmitoyltransferase I (CPT-I), carnitine acylcarnitine translocase (CACT), carnitine palmitoyltransferase II (CPT-II), and the mitochondrial dysfunctions induced by toxic doses of local anesthetics in H9c2 rat cardiomyoblasts. The effects of local anesthetics and lipid emulsions on the activities of CPT-I, CACT, and CPT-II, and concentrations of local anesthetics were examined. The effects of lipid emulsions, N-acetyl-L-cysteine (NAC), and mitotempo on the bupivacaine-induced changes in cell viability, reactive oxygen species (ROS) levels, mitochondrial membrane potential (MMP), and intracellular calcium levels were examined. CACT, without significantly altering CPT-I and CPT-II, was inhibited by toxic concentration of local anesthetics. The levobupivacaine- and bupivacaine-induced inhibition of CACT was attenuated by all concentrations of lipid emulsion, whereas the ropivacaine-induced inhibition of CACT was attenuated by medium and high concentrations of lipid emulsion. The concentration of levobupivacaine was slightly attenuated by lipid emulsion. The bupivacaine-induced increase of ROS and calcium and the bupivacaine-induced decrease of MMP were attenuated by ROS scavengers NAC and mitotempo, and the lipid emulsion. Collectively, these results suggested that the lipid emulsion attenuated the levobupivacaine-induced inhibition of CACT, probably through the lipid emulsion-mediated sequestration of levobupivacaine.

Analgesic effects of different concentrations of ropivacaine in transversalis fascia plane block during laparotomy.

OBJECTIVE: To explore the analgesic effects of different concentrations of ropivacaine in transversalis fascia plane (TFP) block during laparotomy. METHODS: Ninety patients who underwent laparotomy admitted to our hospital from March 2019 to March 2020 were selected as the study subjects and were divided equally into a low concentration group, a medium concentration group, and a high concentration group according to the randomized grouping method. The low concentration group adopted 0.4% ropivacaine 40 ml, the medium concentration group was given 0.5% ropivacaine 40 ml, and the high concentration group was given 0.6% ropivacaine 40 ml. The hemodynamic indexes and the incidence of adverse reactions in the two groups were compared. The Numerical Rating Scale (NRS) was used to assess the postoperative pain in the three groups, the Bruggrmann comfort scale (BCS) was used to assess the comfort level in the three groups, and the Mini-mental State Examination (MMSE) was used to evaluate the postoperative cognitive function of the three groups of patients. RESULTS: The mean artery pressure (MAP) and heart rate (HR) levels at T1 and T2 were significantly lower in the medium concentration group than in the other two groups (P < 0.05). The low concentration group had a significantly higher NRS score at T2 than the medium concentration group and the high concentration group (P < 0.05). A significantly higher BCS score was observed in the high concentration group than the other two groups (P < 0.05). There were significantly higher Ramsay scores and MMSE scores in the medium concentration group than in the low concentration and high concentration groups (P < 0.05). The overall incidence of adverse reactions of the high concentration group was significantly higher than that of the low concentration group (P < 0.05), but showed similar results with the medium concentration group. CONCLUSION: The medium concentration group exhibits a better analgesic effect than the low concentration group and higher safety than the high concentration group. Therefore, the use of medium concentration ropivacaine in TFP block may provide a referential basis for clinical treatment.

Glucocorticoid minimizes local anesthetic infusion requirement through adductor canal block and improves perioperative prosthetic joint range of motion in total knee arthroplasty.

INTRODUCTION: The use of glucocorticoid as local anesthetic adjuvant in single-injection adductor canal block (ACB) is well-documented but its effects in the presence of an indwelling catheter is unclear. The purpose of this study was to determine the impacts of one-time perineural glucocorticoid injection on continuous adductor canal block in patients undergoing total knee arthroplasty. METHODS: A single center retrospective study of 95 patients undergoing unilateral total knee arthroplasty (TKA) was performed. Patients were divided into three groups based on adjuvant received through ACB before continuous catheter placement: a control group with no adjuvant (N = 41), a treatment group with dexamethasone (DEX) as adjuvant (N = 33) and another treatment group with DEX/ Methylprednisolone acetate (MPA) as adjuvant (N = 21). The primary outcome was the amount of ropivacaine administered via patient controlled ACB catheter. Secondary outcomes included numeric pain score, perioperative opioid usage, immediately postoperative prosthetic knee joint active range of motion (AROM), opioid usage at 6 weeks and 3 months, length of stay and discharge disposition. RESULTS: Patients in both treatment groups demonstrated a statistically significant decrease in the requirement of self-administered ropivacaine than the control group on postoperative day (POD) 1 (p<0.001) and POD 2 (p<0.001). There was no significant difference in opioid consumption and pain scores between either treatment group vs. control. Compared to control (66%), more home disposition was observed in the DEX (88%, p = 0.028) and DEX/MPA group (95%, p = 0.011). CONCLUSION: This study suggested that single dose perineural glucocorticoid injection with DEX or DEX/MPA significantly decreased the dose of local anesthetic ropivacaine infusion required through continuous ACB for TKA while maintaining comparable level of pain score and opioid consumption, and significantly more patients were discharged home.

Combination anesthetic therapy: co-delivery of ropivacaine and meloxicam using transcriptional transactivator peptide modified nanostructured lipid carriers in vitro and in vivo.

Combination therapy combining two drugs in one modified drug delivery system is used to achieve synergistic analgesic effect, and bring effective control of pain management, especially postoperative pain management. In the present study, a combination of drug delivery technologies was utilized. Transcriptional transactivator (TAT) peptide modified, transdermal nanocarriers were designed to co-deliver ropivacaine (RVC) and meloxicam (MLX) and anticipated to achieve longer analgesic effect and lower side effect. TAT modified nanostructured lipid carriers (TAT-NLCs) were used to co-deliver RVC and MLX. RVC and MLX co-loaded TAT-NLCs (TAT-NLCs-RVC/MLX) were evaluated through in vitro skin permeation and in vivo treatment studies. NLCs-RVC/MLX showed uniform and spherical morphology, with a size of 133.4 ± 4.6 nm and a zeta potential of 20.6 ± 1.8 mV. The results illustrated the anesthetic pain relief ability of the present constructed system was significantly improved by the TAT modification through the enhanced skin permeation efficiency and the co-delivery of MLX along with RVC that improved pain management by reducing inflammation at the injured area. This study provides an efficient and facile method for preparing TAT-NLCs-RVC/MLX as a promising system to achieve synergistic analgesic effect.

Dexmedetomidine Combined with Femoral Nerve Block Provides Effective Analgesia Similar to Femoral Nerve Combined with Sciatic Nerve Block in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Study.

BACKGROUND: Total knee arthroplasty (TKA) is a severe traumatic procedure, and femoral nerve block (FNB) combined with a sciatic nerve block (SNB) is widely used in TKA. However, injury of the sciatic nerve is clinically reported. Dexmedetomidine (DEX) could reduce stress and inflammation, as well as improve pain in TKA. This study aims to observe the analgesic impact of DEX combined with FNB in TKA. METHODS: Eighty-eight patients undergoing TKA were included and randomly divided into two groups: DF group (FNB combined with DEX 0.6µg/kg before surgery, followed by DEX 0.2-0.4µg/kg/h until articular closure) and SF group (FNB combined with SNB). Each nerve was blocked with 0.375% ropivacaine 20mL, and all patients received general anesthesia routinely. The primary endpoint was the pain visual analog scale (VAS) score during activities at postoperative 24 hours. RESULTS: There was no statistical difference in the pain VAS scores at any time point. The mean duration of analgesia for patients with rescue analgesic requests was comparable between the two groups: 25.4 ± 6.3 hours in the DF group vs 24.8 ± 6.4 hours in the SF group (two-sample t-test, p=0.738). The total dose of sufentanil was similar between groups (P=0.355). The maintenance dose of propofol and dose of rescue analgesics were comparable (all P>0.05). There were no statistical differences in the incidence of adverse events. However, the time to extubate in the DF group was significantly longer than those in the SF group (P<0.001). CONCLUSION: DEX combined with FNB could provide effective analgesia similar to SNB combined with FNB in TKA. CLINICAL TRIAL REGISTRATION: The trial was registered at the Chinese Clinical Trial Registry on November 17, 2019 (identifier: ChiCTR1900027552).

Saddle block anesthetic technique for benign outpatient anorectal surgery.

BACKGROUND: Current American Society of Colorectal Surgery Clinical Practice Guidelines for Ambulatory Anorectal Surgery endorse use of monitored anesthesia care, general anesthesia, or spinal anesthesia based on physician and patient preference. Although several studies support the use of monitored anesthesia care over general anesthesia, the literature regarding spinal anesthesia is limited and heterogenous due to small sample sizes and disparate spinal anesthesia techniques. Saddle block anesthesia is a form of spinal anesthesia that localizes to the lowermost sacral spinal segments allowing for preservation of lower extremity motor function and faster recovery. We accrued one of the largest reported cohort of anorectal procedures using saddle block anesthesia, as such, we sought to evaluate our institutional 12-year experience. METHODS: Patients who underwent a benign anorectal procedure at our outpatient surgery center between July 2008-2020 were retrospectively reviewed. Demographics, surgical factors, perioperative times, and adverse events were collected from the electronic medical records. Saddle block anesthesia was generally performed in the preoperative area using a spinal needle (25-27 gauge) and a single injection technique of a 1:1 ratio local anesthetic mixed with 10% dextrose solution. Between 2.5-5 mg of hyperbaric anesthetic was injected intrathecally in the sitting position and the patient remained upright for 3-10 minutes. This technique of saddle block anesthesia provides analgesia for approximately 1-3 hours. RESULTS: In the study, 859 saddle block anesthesia patients were identified, with a mean age of 44.6 years and American Society of Anesthesia score of 1.9; 609 (70.9%) were male. Surgical indications included lesion removal (27.1%), anal fistula (25.8%), hemorrhoidectomy (24.7%), pilonidal disease (6.3%), anal fissure (5.8%), and a combination of prior (10.2%). Prone jackknife positioning was used in 91.6% of procedures. Saddle block anesthesia most often was performed with bupivacaine (48.9%) or ropivacaine (41.7%). The median procedural saddle block anesthesia time was 11 minutes, surgery time was 17 minutes, anesthesia time was 42 minutes, and recovery time was 91 minutes. Patients spent a median of 3 hours and 53 minutes in the facility. Adverse events included urinary retention (1.9%), conversion to general anesthesia (1.8%), spinal headache (1.5%), hemodynamic instability (0.9%), and injection site reaction (0.3%). CONCLUSION: Demonstrated using the largest known cohort of anorectal patients with saddle block anesthesia, saddle block anesthesia provides an effective method of analgesia to avoid general anesthesia with a low rate of adverse events.

Successful vaginal delivery in a parturient with long QT syndrome type 2 using double-catheter epidural analgesia: A CARE-compliant case report.

RATIONALE: Congenital long QT syndrome (LQTS) can cause syncope or sudden death due to ventricular arrhythmia. Congenital LQTS has 3 major types, 1, 2, and 3. Life-threatening arrhythmias are triggered by emotion in patients with LQTS type 2. As patients with LQTS type 2 have a higher incidence of postnatal cardiac events, careful perinatal management especially during delivery is required. To the best of our knowledge, perinatal management of a patient with LQTS type 2 has not been properly described with consideration to its type-specific risk factors for ventricular tachyarrhythmia. PATIENT CONCERNS: A 36-year-old pregnant woman, gravida 1, para 0, with LQTS type 2 was scheduled to undergo vaginal delivery under epidural labor analgesia in the 38th week of pregnancy. No fainting episodes were reported since she began to take 40 mg of propranolol once daily at the age of 25. Despite this, we instituted maximum preventive measures for the safety of both the parturient and the fetus to minimize the risk of maternal cardiac events throughout the perinatal period. DIAGNOSES: She was diagnosed with LQTS type 2 by genetic testing at the age of 25. INTERVENTIONS: Two epidural catheters were placed at levels T11-T12 and L5-S1. Injection of 0.2% ropivacaine and subsequent infusion of ropivacaine 0.1% with fentanyl (2 µg/mL) was directed through each catheter according to the stage of labor. Concurrently, landiolol, a selective and short-acting ß1 receptor antagonist, was infused intravenously at a dose of 1 to 7 µg/kg/min. OUTCOMES: The delivery proceeded uneventfully without pain. No adverse cardiac events were observed during the perinatal period. LESSONS: Vaginal delivery under epidural labor analgesia using 2 catheters might be a viable option for maternal perinatal care and delivery of patients with LQTS type 2.

Effect of Ropivacaine-Loaded Magnetic Nanoparticles on Ankle Nerve Block in Rats.

AIM: Our study is to determine the influence of ropivacaine-loaded magnetic nanoparticles (MNP/Rop) on ankle nerve block in rats. MATERIALS AND METHODS: MNP/Rop was prepared and then injected intravenously into rats to evaluate its anesthetic effect on rat limbs. Mechanical pain thresholds paw withdrawal threshold (PWT) and paw withdrawal thermal latency (PWL) were employed for the assessment of ankle nerve block in rats. RESULTS: PWT increased from T1 to T4 in each group (P < 0.05). The intergroup comparison determined no distinct difference in the PWT value among the three series at T1 (P > 0.05); however, PWT values at T2-T4 were higher in nerve block control group (NBCG) and MNP/Rop group than in blank group (BG), and they remained slightly higher in MNP/Rop group than in NBCG. The intragroup comparison revealed that from T1 to T4, PWL in each group showed a rising trend. The PWL at T1 showed no evident difference among the three series (P > 0.05); however, PWL values at T2-T4 were higher in NBCG and MNP/Rop group than in BG, and they remained slightly higher in MNP/Rop group than in NBCG. In MNP/Rop group, both PWT and PWL increased with the increase of Fe3O4 load in MNP/Rop (P < 0.05), while PWT and PWL remained unchanged when the load was 2.189%; moreover, PWT and PWL elevated as Rop concentration increased in MNP/Rop (P < 0.05), while they kept unaltered under 40 µL 1% Rop. CONCLUSION: Intravenous injection of MNP/Rop into rats and inhalation of MNP into the ankle joint can effectively block ankle nerve conduction in rats.

Anatomical dimensions of the lumbar dural sac predict the sensory block level of continuous epidural analgesia during labor.

BACKGROUND: The anatomical dimensions of the lumbar dural sac determine the sensory block level of spinal anesthesia; however, whether they show the same predictive value during continuous epidural anesthesia (CEA) remains undetermined. We designed the present study to verify the efficacy of the anatomical dimensions of the lumbar dural sac in predicting the sensory block level during labor analgesia. METHODS: A total of 122 parturients with singleton pregnancies requesting labor analgesia were included in this study. The lumbar dural sac diameter (DSD), lumbar dural sac length (DSL), lumbar dural sac surface area (DSA), and lumbar dural sac volume (DSV) were measured with an ultrasound color Doppler diagnostic apparatus. CEA was performed at the L2-L3 interspace. After epidural cannulation, an electronic infusion pump containing 0.08% ropivacaine and sufentanil 0.4 µg/ml was connected. The sensory block level was determined with alcohol-soaked cotton, a cotton swab, and a pinprick. The analgesic efficacy of CEA was determined with a visual analog scale (VAS). The parturients were divided into two groups, "ideal analgesia" and "nonideal analgesia," and the groups were compared by t test. Pearson's correlation was performed to evaluate the association between the anatomical dimensions of the lumbar dural sac and sensory block level. Multiple linear regression analysis was used to create a model for predicting the sensory block level. RESULTS: In the ideal analgesia group, the height, DSL, DSA, DSV and DSD were significantly smaller, and the body mass index (BMI) was significantly larger (P < 0.05). In addition, the DSL demonstrated the strongest correlation with the peak level of pain block (r = - 0.816, P < 0.0001; Fig. 2A), temperature block (r = - 0.874, P < 0.0001; Fig. 3A) and tactile block (r = - 0.727, P < 0.0001; Fig. 4A). Finally, the multiple linear regression analysis revealed that DSL and BMI contributed to predicting the peak sensory block level. CONCLUSION: In conclusion, our study shows that the sensory block level of CEA is higher when the DSL, DSA, DSV and DSD of puerperae are lower. DSL and BMI can be treated as predictors of the peak sensory block level in CEA during labor analgesia.

Optimum dose of spinal ropivacaine with or without single intravenous bolus of S-ketamine during elective cesarean delivery: a randomized, double-blind, sequential dose-finding study.

BACKGROUND: Maternal hypotension after spinal anaesthesia occurs at a high rate during caesarean delivery and can lead to adverse maternal or foetal outcomes. The aim of this study was to determine the optimal dose of spinal ropivacaine for caesarean section with or without intravenous single bolus of S-ketamine and to observe the rates of hypotension associated with both methods. METHODS: Eighty women undergoing elective caesarean delivery were randomly allocated into either a ropivacaine only or ropivacaine with intravenous S-ketamine group. If the upper sensory level of the patient reached T6 and the visual analogue scale (VAS) scores remained below 3 points before delivery, the next patient had a 1/9th chance of receiving a lower dose or an 8/9th chance of receiving the same dose as the previous patient. If the patient had VAS scores of more than 2 points or needed an extra epidural rescue bolus before delivery, a higher dose was used for the next patient. The primary outcome was the successful use of spinal ropivacaine to maintain patient VAS score of < 3 points before delivery and the incidence of post-spinal hypotension in both groups. Secondary outcomes included the rates of hypotension-related symptoms and interventions, upper sensory level of anaesthesia, level of sedation, neonatal outcomes, Edinburgh Postnatal Depression Scale scores at admission and discharge, and post-operative analgesic effect. The 90% effective dose (ED90) and 95% confidence interval (95% CI) were estimated by isotonic regression. RESULTS: The estimated ED90 of ropivacaine was 11.8 mg (95% CI: 11.7-12.7) with and 14.7 mg (95% CI: 14.6-16.0) without intravenous S-ketamine, using biased coin up-down sequential dose-finding method. The rates of hypotension and associated symptoms were significantly lower in S-ketamine group than in the ropivacaine only group. CONCLUSIONS: A spinal dose of ropivacaine 12 mg with a single intravenous 0.15 mg/kg bolus dose of S-ketamine may significantly reduce the risk of hypotension and induce sedation before delivery. This method may be used with appropriate caution for women undergoing elective caesarean delivery and at a high risk of hypotension or experiencing extreme nervousness. TRIAL REGISTRATION: http://www.chictr.org.cn ( ChiCTR2000040375 ; 28/11/2020).

Effect of intraperitoneal local anesthesia on enhanced recovery outcomes after bariatric surgery: a randomized controlled pilot study.

BACKGROUND: Patients with extreme obesity are at high risk for adverse perioperative events, especially when opioid-centric analgesic protocols are used, and perioperative pain management interventions in bariatric surgery could improve safety, outcomes and satisfaction. We aimed to evaluate the impact of intraperitoneal local anesthesia (IPLA) on enhanced recovery after bariatric surgery (ERABS) outcomes. METHODS: We conducted a prospective double-blind randomized controlled pilot study in adherence to an a priori peer-reviewed protocol. Patients undergoing laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) with an established ERABS protocol between July 2014 and February 2015 were randomly allocated to receive either IPLA with 0.2% ropivacaine (intervention group) or normal saline (control group). We measured pain scores, analgesic consumption and adverse effects. Functional prehabilitation outcomes, including peak expiratory flow (PEF) and the Six Minute Walk Test (6MWT) and Quality of Recovery Survey-40 (QoR-40) scores, were assessed before surgery, and 1 day and 7 days postoperatively. RESULTS: One hundred patients were randomly allocated to the study groups, of whom 92 completed the study, 46 in each group. There were no statistically significant differences between the 2 groups in baseline characteristics or any primary or secondary outcomes. Pain scores and analgesic consumption were low in both groups. There were no adverse events. Significant declines in PEF and 6MWT and QoR-40 scores were noted on postoperative day 1 in both groups; the values returned to baseline on postoperative day 7 in both groups. CONCLUSION: Intraperitoneal local anesthesia with ropivacaine did not reduce postoperative pain or analgesic consumption when administered intraoperatively to patients undergoing LRYGB. Standardization of the ERABS protocol benefited patients, with functional prehabilitation outcomes returning to baseline postoperatively. Trial registration: ClinicalTrials.gov no. NCT02154763.

Comparison of the analgesic effect of ultrasound-guided paravertebral block and ultrasound-guided retrolaminar block in Uniportal video-assisted Thoracoscopic surgery: a prospective, randomized study.

BACKGROUND: The optimal modality for postoperative analgesia after uniportal video-assisted thoracoscopic surgery (UVATS) for the treatment of lung cancer has not yet been determined. Both ultrasound-guided paravertebral block (PVB) and retrolaminar block (RLB) have been reported to be successful in providing analgesia after UVATS. However, which block technique provides superior analgesia after UVATS is still unclear. This randomized study was designed to compare the postoperative analgesic effects and adverse events associated with ultrasound-guided PVB and RLB after UVATS. METHODS: Sixty patients with lung cancer were randomized to undergo ultrasound-guided PVB (group P) or ultrasound-guided RLB (group R). In group P, 30 mL of 0.5% ropivacaine was injected at the T3 and T5 levels via ultrasound-guided PVB (15 mL at each level on the operative side). In group R, 30 mL of 0.5% ropivacaine was injected at the T3 and T5 levels via ultrasound-guided RLB (15 mL at each level on the operative side). The primary outcome was the numerical rating scale (NRS) score within 48 h after surgery. The secondary outcomes were total postoperative sufentanil consumption, time to first analgesic request and adverse events. RESULTS: At 3, 6, 12, 24, 36 and 48 h postoperatively, the NRS score at rest in group P was lower than that in group R (p < 0.05). At 3, 6, 12, 24 and 36 h postoperatively, the NRS score while coughing in group P was lower than that in group R (p < 0.05). The total postoperative sufentanil consumption in group P was significantly lower than that in group R (p < 0.001). Additionally, the time to first analgesic request was longer in group R than in group P (p < 0.0001). The incidence of nausea in group R was higher than that in group P (p < 0.05). CONCLUSIONS: In patients with lung cancer undergoing UVATS, ultrasound-guided PVB with 0.5% ropivacaine provides better analgesia and results in less nausea than ultrasound-guided RLB. Compared with ultrasound-guided RLB, ultrasound-guided PVB seems to be a better technique for analgesia in UVATS. TRIAL REGISTRATION: The name of this study is the Effect And Mechanism Of Ultrasound-guided Multimodal Regional Nerve Block On Acute And Chronic Pain After Thoracic Surgery. This study was registered in the Chinese Clinical Trial Registry ( ChiCTR2100044060 ). The date of registration was March 9, 2021.