Regional Anesthesia for Lumbar Spine Surgery: Can It Be a Standard in the Future?

This paper is an overview of various features of regional anesthesia (RA) and aims to introduce spine surgeons unfamiliar with RA. RA is commonly used for procedures that involve the lower extremities, perineum, pelvic girdle, or lower abdomen. However, general anesthesia (GA) is preferred and most commonly used for lumbar spine surgery. Spinal anesthesia (SA) and epidural anesthesia (EA) are the most commonly used RA methods, and a combined method of SA and EA (CSE). Compared to GA, RA offers numerous benefits including reduced intraoperative blood loss, arterial and venous thrombosis, pulmonary embolism, perioperative cardiac ischemic incidents, renal failure, hypoxic episodes in the postanesthetic care unit, postoperative morbidity and mortality, and decreased incidence of cognitive dysfunction. In spine surgery, RA is associated with lower pain scores, postoperative nausea and vomiting, positioning injuries, shorter anesthesia time, and higher patient satisfaction. Currently, RA is mostly used in short lumbar spine surgeries. However, recent findings illustrate the possibility of applying RA in spinal tumors and spinal fusion. Various researches reveal that SA is an effective alternative to GA with lower minor complications incidence. Comprehensive insight on RA will promote spine surgery under RA, thereby broadening the horizon of spine surgery under RA.

Thoracic fascial planes blocks in operative bed of modified radical mastectomy and their role in alleviating post-mastectomy pain: a prospective randomized study

Background: Proper pain management after modified radical mastectomy is crucial for improving postoperative outcomes, reducing tumor recurrence, enhancing anti-metastatic activity and achieving excellent patient`s satisfaction. Thoracic fascial planes (TFP) blocks are novel, and safe analgesia modalities to control postmastectomy pain. This study was designed to assess the efficacy and safety of intraoperative TFP blocks for providing postoperative analgesia after modified radical mastectomy.Methods: During the period from March 2020 to April 2021, 30 females (ages 25–67 years) were scheduled for elective MRM and selected randomly to one of two groups; group-A included 15 patients who underwent MRM and anesthetized with both general anesthesia and regional anesthesia (TFP blocks), group-B included 15 patients who underwent MRM and anesthetized with only general anesthesia.Results: The group-A had statistically significantly lower pain scores. The time of first rescue nalbuphine dose post-operatively was statistically significantly longer in group-A compared to group-B. The total 24h nalbuphine consumption and postoperative non-steroidal ketorolac requirements/48h were significantly lower in group-A compared to group-B. Satisfaction score in group-A was statistically significantly better than that in group-B.Conclusions: Intraoperative thoracic fascial planes blocks are simple, safe, and highly effective analgesic modalities after breast surgery.

The association of sex with pain scores and perioperative opioid administration following laparoscopic sleeve gastrectomy

Aim: We investigated whether sex is associated with pain scores and opioid administration after laparoscopic sleeve gastrectomy. Materials & methods: We performed a single-center, retrospective analysis of laparoscopic sleeve gastrectomy patients from December 2016–July 2018. Multivariable linear regressions were performed to investigate the association of sex with pain scores and opioid administration. Results: Baseline pain scores were similar between women and men (n = 266; 78% women). Men reported lower pain scores in all phases of care and received more opioids during their hospitalization (ß = 25.48; 95% CI: 5.77–45.20; p = 0.01), compared with women. Conclusion: Our data suggest that women self-report greater postoperative pain scores, while men received more opioids during their hospitalization. Further studies are needed to understand the reasons for such differences in postoperative pain management.

Drug-Drug Interaction Between Orally Administered Hydrocodone-Acetaminophen and Inhalation of Cannabis Smoke: A Case Report

Objective: To determine if a 2-day protocol measuring pharmacokinetic and pharmacodynamic characteristics can demonstrate drug-drug interactions when smoked cannabis is added to orally administered hydrocodone/acetaminophen combination products. Case Summary: A 51-year-old non-Hispanic white male with chronic pain diagnoses participated in a 2-day pilot protocol. The participant attended two 7-hour in-lab days where he received 10 blood draws each day and completed self-administered pain and anxiety surveys. For both days, the participant took his prescribed dose of hydrocodone/acetaminophen (1/2 tablet of 7.5 mg/325 mg combination product) with the addition of 1 smoked pre-rolled marijuana cigarette (labeled as 0.5 g; 22.17% Δ9-tetrahydrocannabinol; 0.12% cannabidiol) on Day 2. Blood specimens were analyzed using mass spectrometry to quantify the difference of plasma hydrocodone levels between Day 1 and Day 2. Results: Compared to Day 1, lower levels of pain and anxiety were reported during Day 2 with the addition of cannabis to oral hydrocodone/acetaminophen. Day 2 pharmacokinetic analysis also revealed more rapid absorption and overall lower levels of hydrocodone in plasma. Discussion: Lower hydrocodone plasma levels in Day 2 may indicate cannabis’s effect on metabolism and reduce the risk of opioid toxicity. The quicker absorption rate of hydrocodone could explain lower pain and anxiety scores reported on the second day. Conclusion and Relevance: A 2-day protocol was able to capture differences across time in pharmacokinetic and pharmacodynamic measurements. Larger studies can be designed to better characterize the potential drug-drug interaction of cannabis and opioids.

A triple-blind randomized clinical trial of different associations between dexamethasone and non-steroids anti-inflammatories for preemptive action in third molar extractions

The aim of this study is to evaluate the preemptive analgesic effects of dexamethasone (DEX) alone or combined with non-steroidal anti-inflammatory drugs (NSAIDs) in third molar surgeries. The subjects were divided into five groups (n = 20 teeth/group); subjects received only 8 mg of dexamethasone 1 h before the surgical procedure (DEX group), or in combination with etodolac (DEX + ETO), ketorolac (DEX + KET), ibuprofen (DEX + IBU), loxoprofen (DEX + LOX). Paracetamol 750 mg was provided as the number of rescue analgesics (NRA). Salivary PGE2 expression was measured preoperatively and at 48 h. Edema and Maximum mouth opening (MMO) were measured postoperatively at 48 h and 7 days. A visual analog scale (VAS) was performed postoperatively at 6, 12, 24, 48, 72 h, and 7 days. Salivary expression of PGE2 showed a decrease only for the DEX group. Edema and MMO and NRA consumption showed no significant differences among the groups (P > 0.05). The VAS showed a significantly lower pain perception at 6 h after the surgery for the DEX + ETO and DEX + KET groups (P < 0.05). The combination of DEX and NSAIDS should be considered for preemptive acute postsurgical pain management in third molar surgery. In some drug associations such as dexamethasone 8 mg + NSAIDS (ETO and KET) in the pre-operative time, only a few rescue analgesics are necessary.

The association of postoperative dexmedetomidine with pain, opiate utilization, and hospital length of stay in children post–Chiari malformation decompression

OBJECTIVE The aim of this study was to determine the association of postoperative dexmedetomidine with markers of pain in children undergoing Chiari malformation decompression. The authors hypothesized that patients receiving dexmedetomidine postoperatively would have decreased cumulative opiate use. They further hypothesized that there would be no difference in median pain scores, outcomes, or medication adverse events. METHODS An IRB-approved retrospective cohort study of patients undergoing Chiari malformation decompression from December 1, 2015, to December 31, 2018, was performed. Patients aged 0–21 years who underwent intradural Chiari malformation decompression at a single institution were included. Data for those who used dexmedetomidine postoperatively were compared with those who did not use dexmedetomidine. The primary outcome was cumulative opiate use throughout hospitalization. Secondary outcomes included pain scores, ancillary medication use, adverse events, hospital and ICU length of stay, readmission rates, and hospital cost. RESULTS The authors reviewed the records of 172 patients who underwent Chiari malformation decompression. Of those patients, 86 received dexmedetomidine postoperatively and 86 did not. Demographics were not different between the groups. Patients who received dexmedetomidine postoperatively received more doses of dexamethasone and were also more frequently exposed to dexmedetomidine intraoperatively (p = 0.028). Patients who received dexmedetomidine postoperatively used fewer morphine equivalents during their admission (1.02 mg/kg vs 1.43 mg/kg, p = 0.003). The patients who received dexmedetomidine postoperatively also had lower median pain scores on postoperative day 0 (0 vs 2, p < 0.001), lower median pain scores throughout the entire admission (1 vs 2, p < 0.001), and lower maximum pain scores recorded (6 vs 8, p = 0.005). Adjusting for steroid dose number and intraoperative dexmedetomidine exposure, postoperative dexmedetomidine remained associated with lower opiate dosing, lower pain scores on postoperative day 0, lower scores throughout hospital stay, and lower maximum pain scores. Patients who received dexmedetomidine had shorter hospital lengths of stay by 19 hours (p < 0.001). There were no statistically significant differences in medication adverse events or hospital costs between the two groups. CONCLUSIONS Postoperative dexmedetomidine use was associated with decreased opiate use, lower pain scores, and shorter hospital length of stay in this cohort. Dexmedetomidine may be considered as a safe adjuvant medication that may have opiate-sparing effects for this patient population.

Standardized Stimulation Protocols Are Needed for Comparable Analysis of Pain-related Evoked Potentials (PREP)

Objective: Pain-related evoked potentials (PREP) are increasingly used to investigate nociception and small-fibre function. Due to lack of a standard stimulation protocol, it is unclear whether results from studies using different protocols are comparable. Aim of the study was to assess the influence of different stimulation parameters on N1P1-amplitudes, N1-latencies and PREP-induced pain intensity. Methods: In a cross-over design we examined 31 healthy volunteers using four different stimulation protocols (number of stimulation electrodes 1 vs. 3, stimulus durations 200 µs vs. 500 µs) in a randomized order. Statistics: paired t-test, ANOVA, correlation analyses. Results: Longer stimulus duration induced higher N1P1-amplitudes (p<0.05) and higher pain intensity (p<0.001). Stimulation with 3 electrodes lead to a lower pain intensity (p<0.01), whereas the N1P1-amplitude and stimulus intensity at twofold of individual pain remained unaffected by the number of electrodes. Also, there was no relation between stimulus intensities and N1P1-amplitudes (one electrode: r=0.079; p=0.646, three electrodes: r=-0.10, p=0.70) was observed. N1-latencies remained comparable between the four protocols.Conclusions and Significance: The use of different stimulation protocols for PREP is limited by relevant differences in the N1P1-amplitudes and evoked pain intensities. Standard consented stimulation protocols are needed to allow data comparison between different labs and studies.

Predicting Post-operative Pain in Lung Cancer Patients using Pre-operative Peak Alpha Frequency

Aims and Objectives: Experimental models of neuropathic pain suggest that individual peak alpha frequency (PAF), measured using electroencephalography (EEG), can predict future pain sensitivity in experimental settings. Here, we tested whether PAF could predict future pain severity in a clinical setting in patients undergoing thoracotomy. Methods: Recorded using wearable around the ear electrodes (cEEGrids), the feasibility and efficacy of pre-operative PAF as a neuro-marker for post-operative pain was assessed in 16 patients undergoing thoracic surgery for lung cancer (age = 67.53 +/- 4.38 [SD]). Patients also provided numerical ratings (0-10) of current, average, and worst pain pre-operatively as well as within three days post-operatively Results and Significance: Pre-operative PAF of less than 9 Hz was highly sensitive (1.0) and specific (0.86) in identifying patients who would go on to experience severe (>7/10) worst pain. Moreover, PAF was negatively correlated with a patients' current, average, and worst post-operative pain. PAF was significantly higher for those reporting lower pain severity compared to those reporting higher pain severity in the immediate post-operative period. This suggests that PAF is a promising neuro-marker to pre-operatively assess individual susceptibility to severe pain in the immediate post-operative period, possibly enabling a more informed assessment of an individual's suitability for surgery.

Effect of Anti-Inflammatory Diets on Pain in Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

Various nutritional therapies have been proposed in rheumatoid arthritis, particularly diets rich in ω-3 fatty acids, which may lead to eicosanoid reduction. Our aim was to investigate the effect of potentially anti-inflammatory diets (Mediterranean, vegetarian, vegan, ketogenic) on pain. The primary outcome was pain on a 10 cm visual analogue scale. Secondary outcomes were C-reactive protein levels, erythrocyte sedimentation rate, health assessment questionnaire, disease activity score 28, tender/swollen joint counts, weight, and body mass index. We searched MEDLINE (OVID), Embase (Elsevier), and CINAHL for studies published from database inception to 12 November 2021. Two authors independently assessed studies for inclusion, extracted study data, and assessed the risk of bias. We performed a meta-analysis with all eligible randomized controlled trials using RevMan 5. We used mean differences or standardized mean differences and the inverse variance method of pooling using a random-effects model. The search retrieved 564 unique publications, of which we included 12 in the systematic review and 7 in the meta-analysis. All studies had a high risk of bias and the evidence was very low. The main conclusion is that anti-inflammatory diets resulted in significantly lower pain than ordinary diets (−9.22 mm; 95% CI −14.15 to −4.29; p = 0.0002; 7 RCTs, 326 participants).

Circadian Variation in the Median Effective Dose of Epidural Ropivacaine for Labor Analgesia

Background: Labor pain perception has been demonstrated to exhibit a circadian rhythm with lower pain scores during the day compared with the night. This study aimed to determine and compare the median effective dose (ED50) of ropivacaine in parturients having epidural labor analgesia during the day vs. during the night.Methods: The study group consisted of 60 nulliparous healthy parturients who were assigned to one of two groups according to the time they requested labor analgesia: Day Group (7:01 am to 7:00 pm) and Night Group (7:01 pm to 7:00 am). A bolus of.15% ropivacaine was administered epidurally and effective analgesia was defined as the attainment of a visual analog scale (VAS) pain score ≤ 10 mm within 30 min. The dose of ropivacaine for the first parturient in each group was 18 mg. The dose for each subsequent parturient was varied with increments or decrements of 3 mg based on the response of the previous subject. The ED50 was calculated using up-down sequential analysis. Probit regression was used to estimate the relative mean potency of ropivacaine between groups.Results: The ED50 (mean [95% CI]) of ropivacaine was lower in the Day Group (17.9 [16.5–19.4] mg) than in the Night Group (20.9 [19.2–22.7] mg) (P = 0.003). The estimate of relative potency for ropivacaine for the Night Group vs. the Day Group was 0.85 (95% CI:0.56–0.98).Conclusions: Under the conditions of this study, the dose requirement for epidural ropivacaine for labor analgesia was ~ 15% greater during the night than during the day.Clinical Trials Registration: Chinese Clinical Trial Registry (No.: ChiCTR1900025269. http://www.chictr.org.cn/showprojen.aspx?proj=36993).