Efficacy and airway complications of Parker Flex-Tip tubes and standard endotracheal tubes during airway manipulation: A meta-analysis and trial sequential analysis.

BACKGROUND: Despite reported superior intubation outcomes associated with Parker Flex-Tip (PFT) tubes compared with those associated with standard polyvinylchloride tubes, the efficacy and safety of PFT tubes remain uncertain. OBJECTIVES: To compare the intubation outcomes between PFT and conventional standard polyvinylchloride tubes. DESIGN: Meta-analysis of randomised controlled trials. DATA SOURCES: Embase, Medline, Google Scholar, PubMed and the Cochrane controlled trials register from inception until 3 January 2021. ELIGIBILITY CRITERIA: All randomised trials comparing intubation outcomes between PFT (PFT group) and standard polyvinylchloride (standard polyvinylchloride group) tubes. RESULTS: Analysis of the 13 eligible trials showed no significant difference in successful first-attempt intubation rate [risk ratio (RR) 1.20, 95% confidence interval (CI) 0.99 to 1.44] (6 trials, 568 participants), trauma risk (RR 0.83, 95% CI 0.67 to 1.03) (5 trials, 501 participants) as well as the overall risks of epistaxis (RR 0.58, 95% CI 0.26 to 1.31) (3 trials, 262 participants), sore throat (RR 0.90, 95% CI 0.70 to 1.17) (4 trials, 451 participants) and hoarseness (RR 0.71, 95% CI 0.44 to 1.14) (4 trials, 451 participants) between the two groups. However, the intubation time was slightly shorter (weighted mean difference -4.2 s, 95% CI -7.4 to -1.0 s) (8 trials, 759 participants) and the risks of severe epistaxis (RR 0.15, 95% CI 0.03 to 0.84) (3 trials, 262 participants) and overall difficulty in airway manipulation (RR 0.48, 95% CI 0.29 to 0.80) (8 trials, 647 participants) were lower in the PFT group than those in the standard polyvinylchloride group. Trial sequential analysis conclusively confirmed a shorter intubation time with PFT tubes than with standard polyvinylchloride tubes, whereas other intubation outcomes were inconclusive. CONCLUSION: The use of PFT tubes for airway manipulation was associated with a shorter intubation time compared with the standard polyvinylchloride tubes. The results of trial sequential analysis suggest the need for further trials and meta-analysis to compare other intubation outcomes associated with the two devices. TRIAL REGISTRATION: PROSPERO CRD42020197670.

Are Risk Factors for Postoperative Significant Hemorrhage following Total Knee Arthroplasty Potentially Modifiable? A Retrospective Cohort Study.

Total knee arthroplasty (TKA) is the treatment of choice for end-stage osteoarthritis (OA) of the knee, because it alleviates pain and restores function of the knee. However, TKA-associated hemorrhage and subsequent anemia remain a concern. Most previous studies have defined meaningful postoperative bleeding as blood loss > 500 mL or hemoglobin (Hb) drop > 20 g/L. Therefore, we defined significant hemorrhage as a postoperative Hb drop more than 20 g/L in this study, and we investigated possible risk factors related to significant hemorrhage in TKA and whether these risk factors are modifiable. This retrospective study was conducted through a comprehensive review of the perioperative records of patients with OA of the knee who underwent TKA between January 2009 and December 2015 at our hospital. Patients were allocated into two groups: patients in Group A had their Hb drop ≤ 20 g/L; patients in Group B had their Hb drop > 20 g/L. Factors analyzed included sex, age, body mass index (BMI), the American Society of Anesthesiologists (ASA) classification, comorbidities, preoperative platelet count, use of tranexamic acid (TXA), operation time, and type of anesthesia. A total of 3350 patients met the criteria for analysis, with 1782 patients allocated to Group A and 1568 patients to Group B. Five independent risk factors for significant hemorrhage were identified: male sex (odds ratio(OR), 1.29; 95% confidence interval(CI), 1.08−1.53; p = 0.005), age (OR, 1.02; 95% CI, 1.01−1.03; p = 0.001), use of TXA (OR, 0.39; 95% CI, 0.34−0.45; p < 0.001), spinal anesthesia versus general anesthesia (OR, 0.71; 95% CI, 0.56−0.90; p = 0.004), and preoperative platelet count (OR, 0.96; 95% CI, 0.93−0.98; p = 0.001). Of these identified risk factors, preoperative platelet count, use of TXA, and spinal anesthesia are modifiable. These potentially modifiable risk factors need to be taken into consideration when making both the perioperative care and anesthesia plan by surgeons and anesthesiologists, especially in patients at risk of significant hemorrhage.

Comparison of Back-Propagation Neural Network, LACE Index and HOSPITAL Score in Predicting All-Cause Risk of 30-Day Readmission.

BACKGROUND: The main purpose of this study is to predict the all-cause risk of 30-day readmission by employing the back-propagation neural network (BPNN) in comparison with traditional risk assessment tools of LACE index and HOSPITAL scores. METHODS: This was a retrospective cohort study from January 1st, 2018 to December 31st, 2019. A total of 55,688 hospitalizations from a medical center in Taiwan were examined. The LACE index (length of stay, acute admission, Charlson comorbidity index score, emergency department visits in previous 6 months) and HOSPITAL score (hemoglobin level at discharge, discharge from an Oncology service, sodium level at discharge, procedure during hospital stay, Index admission type, number of hospital admissions during the previous year, length of stay) are calculated. We employed variables from LACE index and HOSPITAL score as the input vector of BPNN for comparison purposes. RESULTS: The BPNN constructed in the current study has a considerably better ability with a C statistics achieved 0.74 (95% CI 0.73 to 0.75), which is statistically significant larger than that of the other two models using DeLong's test. Also, it was possible to achieve higher sensitivity (70.32%) without penalizing the specificity (71.76%) and accuracy (71.68%) at its optimal threshold, which is at the 20% of patients with the highest predicted risk. Moreover, it is much more informative than the other two methods because of a considerably higher LR+ and a lower LR-. CONCLUSION: Our findings suggest that more attention should be paid to methods based on non-linear classification systems, as they lead to substantial differences in risk-scores.

Is There an Optimal Timing of Adductor Canal Block for Total Knee Arthroplasty?-A Retrospective Cohort Study.

Adductor canal block (ACB) has gained popularity for postoperative pain control after total knee arthroplasty (TKA). However, its role in TKA has been questioned recently. Our study aimed to clarify the role of ACB in reducing postoperative pain after TKA and to elucidate an optimal timing to perform ACB for better outcomes. We conducted a comprehensive review of the perioperative records of 652 patients undergoing primary TKA from January 2019 to December 2019. Patients were divided into three groups: Group A received general anesthesia without ACB, Group B received ACB before inducing general anesthesia, and Group C received ACB at the post-anesthesia recovery unit (PACU). Patients in Groups B and C had lower pain visual analogue scale (VAS) scores than patients in Group A at the PACU. Opioid consumption was similar among the three groups; however, a slightly higher dose was required by Group A patients. Higher VAS scores were recorded in the ward in Group A than in Groups B and C with the leg at rest. In addition, higher VAS scores were recorded in Group A than in Groups B and C with the leg in continuous passive motion (CPM) training. More patients in Group A (34.9%) quit their first CPM training after a few cycles than those in Groups B (27.0%) and C (20.1%). Group A patients required a higher per kg dose of opioids in the ward than Groups B and C patients. Additionally, the hourly consumption of sevoflurane was similar among the three groups of patients, while Group A and C patients required a higher hourly per kg dose of intraoperative opioids than Group B patients. More patients in Group A (67.6%) and C (61.7%) developed intraoperative hypertension than patients in Group B (52.7%). There was no significant difference in PON (postoperative nausea), POV (postoperative vomiting), postoperative dizziness, or patient satisfaction among the three groups of patients. Group A patients had a longer length of hospital stay compared to Group B and C patients. In conclusion, preoperative ACB could be a better choice for patients undergoing TKA as it decreases intraoperative opioid consumption and facilitates a stable hemodynamic state during surgery.

Earlier Is Better? Timing of Adductor Canal Block for Arthroscopic Knee Surgery under General Anesthesia: A Retrospective Cohort Study.

The adductor canal block (ACB) is effective for treating postoperative pain during arthroscopic knee surgery, but its impact on anesthesia course and the optimal administration timing are unknown. This retrospective study addressed these questions. The aim of this study was to compare the effects of preoperative ACB and postoperative ACB on anesthesia course and postoperative recovery. We allocated 215 adult patients who underwent arthroscopic knee surgery under sevoflurane anesthesia between January 2019 and December 2019 to three groups. Group A received general anesthesia without ACB, Group B received ACB before general anesthesia induction, and Group C received ACB in the post-anesthesia recovery unit (PACU). Group B consumed significantly less sevoflurane (0.19 mL/kg/h) and milligram morphine equivalents (0.08 MME) intraoperatively than Groups A (0.22 mL/kg/h; 0.10 MME, respectively) and C (0.22 mL/kg/h; 0.09 MME, respectively). Groups B and C had lower visual analogue scale (VAS) scores upon PACU discharge than Group A. Dynamic, but not at-rest VAS scores, were significantly higher in Group A. Opioid consumption was similar in the ward, but Group A requested more intravenous parecoxib for pain relief. Length of hospital stay was similar. Thus, preoperative ACB reduced the amount of volatile anesthetic required and maintained stable hemodynamics intraoperatively. Preoperative or postoperative ACB improved postoperative pain control. Consequently, preoperative ACB is optimal for intraoperative stress suppression and postoperative pain control.

Risk Factors of Postoperative Vomiting in the Eye of "Real-World Evidence"-Modifiable and Clinical Setting-Dependent Risk Factors in Surgical Trauma Patients.

Numerous studies on postoperative nausea and vomiting (PONV) have been carried out since the early days of contemporary surgery. The incidence of PONV has been greatly reduced in recent years and new drugs for PONV keep evolving in the market; however, a substantial number of patients are still under the threat of PONV. Female gender, non-smokers, a history of PONV/motion sickness, and postoperative opioid use are four well-recognized risk factors of PONV. Many potential risk factors reported in previous studies were not consistently presented as predictors for PONV. Two questions then arise; are risk factors clinical setting dependent and are risk factors modifiable? We attempted to answer the questions through a comprehensive review of perioperative records of surgical patients from the Trauma Department of our hospital. As nausea is subjective and no standard is applicable for its measurement, postoperative vomiting (POV) was used as an endpoint in this study. To the best of our knowledge, this is the first study to address the POV issue in surgical trauma patients. A total of 855 patients were enrolled in this study after excluding age below 20 years old, total intravenous anesthesia, desflurane anesthesia, or records with missing data. Our results showed that female gender (OR 4.89) is the strongest predicting factor, followed by a less potent predicting factor-more intraoperative opioid consumption (OR 1.07)-which favor more POV. More intraoperative crystalloid supply (OR 0.71) and a higher body weight (OR 0.9) favor less POV. Other potential risk factors did not reach statistical significance in this study as independent risk factors. Our results also showed that when the intraoperative crystalloid infusion rate is greater than 4 mL/kg/h (OR 0.20), it favors a lower rate of POV; when intraoperative opioid consumption is greater than 12 mg morphine equivalents, MME (OR 1.87), it favors a higher rate of POV. We concluded that dominance of any independent risk factor over other risk factors depends on how individual factors interact with the clinical setting. Some risk factors could be modified, and a cut-off value could be derived to facilitate a better plan for POV prevention.

Sevoflurane versus desflurane for early postoperative vomiting after general anesthesia in hospitalized adults: A systematic review and meta-analysis of randomized controlled trials.

STUDY OBJECTIVE: This systematic review and meta-analysis aimed at assessing the effects of two commonly used anesthetics in general anesthesia (GA), sevoflurane and desflurane, on early postoperative vomiting (POV) in hospitalized adults. DESIGN: Systematic review and meta-analysis of randomized controlled trials (RCTs). SETTING: Early postoperative vomiting after GA. PATIENTS: A total of 266 adult patients receiving inpatient surgeries under GA maintained with sevoflurane or desflurane. INTERVENTIONS: We searched PubMed, Medline, Cochrane Central Register of Controlled Trials, ScienceDirect, and Embase for eligible RCTs comparing postoperative outcomes following sevoflurane- or desflurane-maintained anesthesia. MEASUREMENTS: The primary outcome was early POV. Secondary outcomes included late POV, early and late postoperative nausea (PON), time to extubation, and emergence time. MAIN RESULTS: Eight trials were included. There was no significant difference in the risk of early POV (risk ratio [RR] 1.03, 95% confidence interval [CI] 0.64-1.64, p = 0.91). No significant difference in early PON was observed (RR 1.09; 95% CI, 0.77-1.56; p = 0.62). Nevertheless, the incidence of late POV and late PON were significantly lower in the sevoflurane group than that in the desflurane group (RR 0.47, 95% CI 0.23-0.94, p = 0.03; RR 0.45, 95% CI 0.24-0.84, p = 0.01, respectively). The extubation time was longer in the sevoflurane group than in the desflurane group (standardized mean difference [SMD] 0.56, 95% CI 0.14-0.97, p = 0.009). The emergence time of patients in the sevoflurane group was longer than that in those receiving desflurane (SMD 0.76, 95% CI 0.1-1.42, p = 0.02). CONCLUSIONS: Desflurane had the same effects on early POV and early PON as sevoflurane. However, the association between late POV and late PON with desflurane was stronger than that with sevoflurane if the effects of opioids were not considered. The desflurane group had shorter time to extubation and emergence time than the sevoflurane group. PROSPERO registration number: CRD42020218988.

Implementation of an Anaesthesia Quality Improvement Programme to Reduce Fibreoptic Bronchoscope Repair Incidents.

BACKGROUND: This study was aimed at investigating the effectiveness of the implementation of a comprehensive quality improvement programme (QIP) for reducing the repair rate of the fibreoptic bronchoscope (FOB). METHODS: A three-stage improvement strategy was implemented between January 2013 and December 2016. Stage one is the acquisition of information on violations of practice guidelines, repair rate, cost of repair, and incidence of unavailability of FOB during anaesthesia induction of the previous year through auditing. Stage two is the implementation of a quality improvement campaign (QIC) based on the results of stage one. Stage three is the programme perpetuation through monitoring compliance with policy on FOB use by regular internal audits. The effectiveness was retrospectively analyzed on a yearly basis. RESULTS: The annual repair rate, repair cost, and incidence of FOB unavailability before the QIP implementation were 1%, 18,757 USD, and 1.4%, respectively. After QIC, the repair rate in 2013 dropped by 81% (from 1% in 2012 to 0.19% in 2013, p < 0.05). The annual repair cost fell by 32% from 18,758 USD (2012) to 12,820 USD (2013). Besides, the incidence of FOB unavailability plummeted by 71% from 1.4% to 0.4% during the same period. The annual repair rates and incidence of FOB unavailability remained lower in subsequent three years than those before QIP implementation. CONCLUSION: Implementation of a quality improvement programme was effective for reducing the rate and cost of FOB repair as well as unavailability rate, highlighting its beneficial impact on cost-effectiveness and patient safety in a tertiary referral center setting.

"A real-world evidence" in reduction of volatile anesthetics by BIS-guided anesthesia.

Many well-controlled clinical studies have shown that BIS-guided anesthesia could prevent intraoperative awareness and improve postoperative morbidity and mortality, by optimizing the amount of volatile anesthetics administered to patients. However, we questioned if the previously reported advantages of BIS-guided anesthesia in controlled studies would still apply in real-world settings. This retrospective study based on real-world settings clarified the role of BIS-guided anesthesia in reducing anesthetic consumption. We obtained anesthesia records from an electronic database of a medical center in southern Taiwan. A total of 6,713 cases were enrolled, where 1,324 cases receiving sevoflurane underwent BIS-guided anesthesia and 378 received desflurane; further, 3,819 receiving sevoflurane underwent standard anesthesia practice and 1,192 cases received desflurane. The median (25-75% interquartile values) of the average hourly consumption of sevoflurane or desflurane decreased significantly under BIS-guided anesthesia [10.5 (8.7-13.0) mL/h and 17.4 (13.7-21.1) mL/h, respectively] compared to that under standard anesthesia practice [11.4 (9.0-14.5) mL/h, and 20.2 (15.8-25.0), mL/h, respectively]. Furthermore, the average hourly consumption of these two volatile anesthetics varied inversely with age and anesthesia time in both groups. A significant reduction was found in the hourly consumption of volatile anesthetics in patients under BIS-guided anesthesia compared to standard anesthesia practice in different age groups or different anesthesia time. We concluded that BIS-guided anesthesia could reduce consumption of volatile anesthetics in real-world settings as well.

Malignant lymphoepithelial lesions of the salivary gland.

OBJECTIVES: To describe a relatively large series of patients with uncommon malignant lymphoepithelial lesions (MLEL) in the salivary glands, to present treatment-outcome data to support therapeutic decision-making, and to evaluate the incidence of co-occurrence of MLEL and Epstein-Barr virus (EBV). STUDY DESIGN AND SETTING: Ten patients with MLEL were treated between 1987 and 2002. All lesions were surgically removed, with or without neck dissection, and the patients treated with radiotherapy or radiotherapy and chemotherapy. Histopathology and in situ hybridization studies for EBV-encoded RNA (EBER1) were performed. RESULTS: With aggressive treatment, outcomes were good, regardless of the presenting stage, except when distal metastases were present. All 10 patients tested positive for EBV. CONCLUSION AND SIGNIFICANCE: This and previous investigations support the use of aggressive surgical excision of the tumor and local metastases and radiotherapy or radiotherapy and chemotherapy, as optimal treatment for MLEL. The EBV finding may indicate a role for EBV in the pathogenesis of MLEL. EBM RATING: C-4.

Young age, male sex, and end-stage renal disease with secondary hyperparathyroidism as risk factors for intraoperative hyperkalemia during parathyroidectomy.

STUDY OBJECTIVE: The aim of this study was to investigate the risk factors of intraoperative hyperkalemia in end-stage renal disease patients undergoing parathyroidectomy (PTx) with autotransplantation (AT). DESIGN: Prospective observational study. SETTING: Operating room of a tertiary care medical center. PATIENTS: Thirty-two adult, American Society of Anesthesiologists physical status 2 and 3 patients with secondary hyperparathyroidism aged between 31 and 72 years scheduled for PTx with AT. MEASUREMENTS: Laboratory chemistries (intact parathyroid hormone, Na, K, Ca, P, arterial blood gas) were obtained before surgery and at 2 time points during surgery. The first chemistry levels during surgery were checked after the first 2 parathyroid glands had been removed, and the second levels were checked after wound closure. Statistical analysis was performed using t test, Fisher exact test, the receiver operating characteristic curve method, as appropriate. MAIN RESULTS: Eight patients (25%) developed hyperkalemia during surgery. The hyperkalemia patients had younger age (42±11.44 years vs 52.58±11.83 years, P=.044) and a male dominance (odds ratio, 11.4; P=.01; 95% confidence interval, 1.74-74.65). The cutoff for age was 40.5 years, according to the highest value for sensitivity plus specificity of the receiver operating characteristic curve. There was a higher incidence of intraoperative hyperkalemia in younger patients than in older patients (odds ratio, 8.33; P=.023; 95% confidence interval, 1.39-49.87) as well as a significant increase in potassium level during surgery in younger male patients (P=.005 and .002, respectively). CONCLUSIONS: The anesthesiologist should be aware of the complications of intraoperative hyperkalemia during PTx with AT, especially in male end-stage renal disease patients younger than 40 years.

Lidocaine: the optimal timing of intravenous administration in attenuation of increase of intraocular pressure during tracheal intubation.

BACKGROUND: This study was designed to examine the optimal timing of intravenous lidocaine in attenuation of increase of intraocular pressure in response to laryngoscopy and tracheal intubation during induction of anesthesia. METHODS: One hundred and thirty five adult patients of ASA class I, aged between 20-35 years, undergoing surgical procedures irrelevant to ophthalmology were enrolled for study. Patients were randomly assigned to one of five groups. In group II, III, IV and V the patients received intravenous injection of lidocaine (2 mg/kg), 1, 3, 5, 10 min before tracheal intubation, respectively. Group I in which patients did not receive lidocaine served as the control group. RESULTS: In patients of groups I, IV and V, the intraocular pressure increased significantly after intubation, whereas in those of groups II and III, the intraocular pressure did not. All patients in the five groups showed concomitantly a surge of blood pressure, but the magnitude of increase was smallest in group III in comparison with the other groups. The values of systolic and diastolic pressures 1 min after intubation were significantly less in groups III and IV than in the control group. CONCLUSIONS: In healthy patients aged between 20 and 35 the most optimal time of administration of intravenous lidocaine to attenuate the increase of intraocular pressure seemed to be the space between 1 to 3 min before laryngoscopy and tracheal intubation.

The hemodynamic effect of an intravenous antispasmodic on propofol requirements during colonoscopy: A randomized clinical trial.

PURPOSE: Hemodynamic status during induction of anesthesia may modify the amount of propofol needed to induce loss of consciousness (LOC). This study was aimed to evaluate the effect of antispasmodic-induced tachycardia on the concentration of propofol at the effect-site for inducing LOC when deep sedation was executed for colonoscopy. METHODS: One hundred and sixteen adult patients were randomly assigned to receive either 20 mg of the antispasmodic Buscopan intravenously (Buscopan group; n = 58) or normal saline (control group; n = 58) for colonoscopy. After administration of Buscopan, the antispasmodic or normal saline, propofol was given by means of target-controlled infusion to induce LOC. We recorded patient characteristics, hemodynamic profiles, effect-site propofol concentration upon LOC, total propofol dosage for colonoscopy, and colonoscopy outcomes. RESULTS: There were no significant differences in the characteristics between the two groups. Although the patients receiving Buscopan had a higher heart rate than those of the control group (101 ± 15 beats/minute vs. 77 ± 13 beats/minute; p < 0.001), we found no significant difference between two groups in the effect-site propofol concentration for inducing LOC (3.9 ± 0.6 µg/mL vs. 3.8 ± 0.6 µg/mL; p = 0.261) nor total propofol dosage required for colonoscopy (3.2 ± 1.4 mg/kg vs. 3.1 ± 1.1 mg/kg; p = 0.698). Both groups had comparable colonoscopy outcomes, including percentage of patients completing the procedure and total procedure time. CONCLUSION: The hemodynamic responses to intravenous Buscopan neither affected the effect-site propofol concentration needed to induce LOC, nor the total propofol dosage required for colonoscopy in this study. There is no need to modify the dosage of propofol in patients subject to Buscopan premedication in colonoscopy.

Acute coronary syndrome in cisatracurium-induced anaphylactic shock: Kounis syndrome.

In this case report, we describe a 70-year-old male patient who sustained Kounis syndrome induced by cisatracurium administration immediately following induction of general anesthesia. Acute coronary syndrome combined with anaphylactic shock, termed Kounis syndrome, should be investigated in percutaneous coronary intervention to solve this complex and life-threatening condition. A team effort by cardiologist and anesthesiologist is essential for successful resuscitation. In general, the incidence of an anaphylactic reaction to cisatracurium is low, but a high serum IgE level in combination with a positive skin prick test in our patient was strongly suggestive of cisatracurium-induced Kounis syndrome. In addition, a cross-reaction between cisatracurium and rocuronium is reported.

Intrathecal midazolam combined with low-dose bupivacaine improves postoperative recovery in diabetic mellitus patients undergoing foot debridement.

BACKGROUND: Intrathecal midazolam acts synergically with other anesthetics to relieve surgical pain, and the drug combination may decrease complications attributable to each component drug. This prospective study was to determine the spinal effects of low-dose of bupivacaine (5 mg) combined with intrathecal midazolam (2 mg) in diabetes mellitus (DM) patients undergoing foot debridement. METHODS: Sixty diabetic patients were admitted for foot debridement under spinal anesthesia were equally divided into two groups. Group 1 (M) received 7.5 mg of hyperbaric bupivacaine; group 2 (M+M) received 5 mg of hyperbaric bupivacaine combined with 2 mg of midazolam intrathecally. The intensity of motor block was assessed with modified Bromage scale 20 minutes after injection, and at 0, 30, 60, 90 and 120 min after arriving at the post anesthesia care unit (PACU). Pain score was assessed with a 10 cm visual analog scale (VAS, 0 = no pain and 10 = intolerable pain) at 0, 1, 2, 6 h and 24 h postoperatively. RESULTS: Anesthesia was smooth in all patients except one in group M, whose analgesia was inadequate and general anesthesia was given to complete the surgery. The number of patients who sustained moderate to severe pain (VAS > 5) was significantly less in the M+M group than in M group as accessed 6 and 24 h postoperatively. The requirement of additional analgesic as reinforcement was significantly less in the M+M group than in the M group within the space of 24 h postoperatively. Recovery of motor function was significantly faster in the M+M group. CONCLUSIONS: The combination of intrathecal midazolam and bupivacaine was a safe and effective anesthetic technique, and it also provided early recovery of motor function and reduced the requirement of analgesics postoperatively.

Immunoneutralization of c-Fos using intrathecal antibody electroporation attenuates chronic constrictive injury-induced hyperalgesia and regulates preprodynorphin expression in rats.

BACKGROUND: In vivo electroporation has been successfully used for the introduction of DNA, RNA, oligonucleotides, and proteins into cells for experimental and therapeutic purposes. The authors evaluated the efficacy of electroporation-mediated c-Fos antibody therapy for neuropathic pain in vitro and in vivo. METHODS: First, the authors studied the inhibitory effects of intrathecal c-Fos antibody electroporation on the activating protein (AP-1) promoter activity in cultured spinal neuronal cells transfected with p-AP-Luc plasmid and activated with 100 microm glutamate. The inhibitory effect of c-Fos antibody electroporation in the regulation of AP-1 promoter activity was assessed according to the relative luciferase activity. Second, rats with chronic constrictive injury underwent electroporation treatment for neuropathic pain using c-Fos antibody. Thermal nociceptive thresholds were measured before chronic constrictive injury and then on even-numbered days, up to and including day 14, to assess and compare the therapeutic effects of intrathecal electroporation. The time course was assessed by Western blot analysis and by immunohistochemical analysis. Pronociceptive gene expression was measured by assessing prodynorphin mRNA and dynorphin peptides on days 2 and 10 after intrathecal c-Fos electroporation. RESULTS: Cotransfection of c-Fos antibody significantly decreased glutamate-induced AP-1 activity. Intrathecal electrotransfer of c-Fos antibody attenuated spinal dynorphin levels, as manifested by significantly elevated pain thresholds in the chronic constrictive injury-affected limbs. CONCLUSION: This study shows that transfer of antibody into rat spinal cords by intrathecal electroporation is a useful method to study the function of endogenous factors of spinal-related disorders.