Interpectoral and Pectoserratus Plane Block vs. Local Anesthetic Infiltration for Partial Mastectomy: A Prospective Randomized Trial.

appears neither logical nor beneficial to patients.

Surgical procedures and anesthesia, while essential for treating patient conditions, often induce uncomfortable symptoms, such as nausea and vomiting.These symptoms manifest not only intraoperatively (i.e., intraoperative nausea and vomiting [IONV]), but also postoperatively (i.e., postoperative nausea and vomiting [PONV]), contributing to delayed recovery and increased healthcare costs [1].In this issue of the Korean Journal of Anesthesiology, we feature two studies that emphasize distinct approaches to reducing IONV during spinal anesthesia and PONV following general anesthesia.Nausea and vomiting are common complications of spinal anesthesia that stem from sympathetic blockade-induced hypotension and increased gastrointestinal peristalsis.Preventing IONV is essential not only for improving patient satisfaction with intraoperative anesthesia, but also for reducing the risk of aspiration.Benzodiazepines can reduce nausea and vomiting by decreasing the dopamine input at the chemoreceptor trigger zone in the central nervous system [2].In patients undergoing cesarean section under spinal anesthesia, IONV incidence rates have been reported to be as high as 80% [3]. Lee et al. [4] found that remimazolam, a benzodiazepine with rapid onset and offset characteristics, significantly decreased both the incidence and severity of IONV compared with midazolam.Remarkably, remimazolam demonstrated hemodynamic stability, with no significant differences in vital signs compared with midazolam, even while achieving deeper sedation.Furthermore, recent meta-analyses suggest that in total intravenous anesthesia, remimazolam does not increase PONV risk compared to propofol and reduces PONV incidence compared to volatile anesthetics [5], suggesting broader applicability of remimazolam in anesthesia.Opioids serve as an essential component of balanced anesthesia, contributing to the stabilization of vital signs and attenuation of surgical stimuli during general anesthesia.However, opioids are also well-known risk factors for PONV, particularly among women and non-smokers.According to the enhanced recovery after surgery (ERAS) guidelines, opioid-sparing strategies are strongly recommended to lower the incidence of PONV [6].The fourth consensus guidelines for PONV management also advocate minimizing both intraoperative and postoperative opioid use; however, most studies focus on the effects of postoperative opioid use [7].Nam et al. [8] demonstrated that opioid-sparing anesthesia reduces nausea in the post-anesthesia care unit after laparoscopic gynecological surgery.Their study distinguished patients who received continuous intraoperative opioid exposure from those who received opioids only at the time of induction.Additionally, postoperative pain control relies primarily on non-steroidal anti-inflammatory drugs and non-opioid rescue analgesics via intravenous patient-controlled analgesia, which allows for an objective assessment of the impact of intraoperative opioid use on PONV.The conclusions of this study were strengthened by a subgroup analysis that excluded patients

AS part of the effort to develop mechanisms-based approaches to pain therapy, renewed interest has focused on the use of ketamine for treatment of acute and chronic pain. In particular, the role of N -methyl-d-aspartate (NMDA) excitatory glutamate receptors in nociceptive transmission has been established in humans.1–3NMDA receptors participate in the development and maintenance of what can be called “pathologic pain” after tissue injury: increased pain perception as a result of pain sensitization, in part from synaptic plasticity.1–3Ketamine binds noncompetitively to the phencyclidine binding site of NMDA receptors4but also modifies them via allosteric mechanisms.5When studied at subanesthetic doses, its analgesic efficacy correlates well with its inhibiting action on NMDA receptor-mediated pain facilitation4,6and a decrease in activity of brain structures that respond to noxious stimuli.7Ketamine therefore represents a promising modality in several perioperative strategies to prevent pathologic pain.Another reason for the renewed interest in ketamine is the availability of S(+) ketamine. Ketamine has a chiral center at the carbon-2 atom of the cyclohexanone ring, and therefore exists as the optical stereoisomers S(+) and R(-) ketamine.4Until recently, ketamine was marketed as a racemate, containing equimolar amounts of the enantiomers. S(+) ketamine has a fourfold greater affinity for NMDA receptors than does R(-) ketamine.4This difference results in a clinical analgesic potency of S(+) ketamine approximately two times greater than that of racemic and four times greater than that of R(-) ketamine, whereas S(+) ketamine has a shorter duration of action.4,6,8We discuss the perioperative use of ketamine as an adjunct to general and regional anesthesia and to postoperative pain therapy. Focus will be on the administration of the drug at subanesthetic concentrations; we will refer to this as “subanesthetic ketamine.”Intravenous subanesthetic ketamine, when added as an adjunct to general anesthesia, reduced postoperative pain and opioid requirements in a variety of settings, from outpatient surgery to major abdominal procedures (level II evidence) (table 1).9–16However, some studies did not show this benefit (level II evidence) (table 1).17,18Two factors may explain these failures. First, beneficial effects of ketamine may be masked when the drug is used in small doses (<0.15 mg/kg) against the background of multimodal or epidural analgesia.17Second, the dosing schedule may be inadequate. Studies have compared the effects of ketamine administration before surgery with those of one ketamine administration at the end of surgery to test its “preemptive” analgesic properties. However, nociceptive and inflammatory signals are generated throughout surgery and after the procedure. A single injection of a short-acting drug such as ketamine either before or after incision will therefore not provide analgesia that lasts far into the postoperative period.18To prevent pathologic pain, ketamine needs to be applied at least throughout the operation and likely for a period of time into the postoperative phase, in an attempt to reduce sensitization of central and peripheral pain pathways. Thus, the adequacy of the ketamine administration schedule is a crucial component for pain prevention (fig. 1).Dosing of ketamine when used for this purpose is affected by variety of factors, including the expected amount of pain, whether general or epidural anesthesia will be used, and whether ketamine will be applied intraoperatively or intraoperatively and postoperatively (level II evidence) (table 1). In a long-term outcome trial on adenocarcinoma surgery with general or epidural anesthesia, racemic ketamine injected as a 0.5 mg/kg preincisional bolus followed by an infusion of 0.25 mg·kg−1·h−1reduced postoperative morphine needs and the incidence of residual pain until the sixth postoperative month.13However, this was not the case when the drug was used at half the dose. After gastrectomy12or major renal surgery14with general or epidural anesthesia, ketamine improved postoperative pain relief after an intraoperative infusion of 500 μg·kg−1·h−1preceded by a preincisional bolus of 1 mg/kg14or 0.5 mg/kg.12In patients undergoing major pelvic visceral procedures with general or epidural anesthesia, we found less postoperative pain when 0.5 mg/kg preincisional S(+) ketamine was followed by repeated 0.2 mg/kg boluses, as compared with preincisional S(+) ketamine alone.16After radical prostatectomy with general anesthesia, opiate needs and pain at rest were reduced after a 0.1 mg/kg preoperative S(+) ketamine bolus and an intraoperative infusion of 120 μg·kg−1·h−1, followed by patient-controlled analgesia (PCA) with boluses of 1 mg morphine and 0.5 mg S(+) ketamine.15In less painful surgery such as nephrectomy, a preincisional bolus of 0.5 mg racemic ketamine followed by a 24 h-infusion of 120 μg·kg−1·h−1and then of 60 μg·kg−1·h−1for 48 h reduced hyperalgesia surrounding the incision.11The following dosing schedule can therefore be proposed: In painful procedures, a 0.5 mg/kg slow bolus injection of ketamine before or after induction of general anesthesia, but before incision, may be used; this may be followed by repeated injections of 0.25 mg/kg ketamine at 30-min time intervals or a continuous infusion of 500 μg·kg−1·h−1. For procedures lasting longer than 2 h, drug administration ends at least 60 min before surgery to prevent prolonged recovery. In procedures expected to be less painful, a 0.25 mg/kg ketamine bolus before incision may be injected; this may be followed by 30-min injections of 0.125 mg/kg ketamine or an infusion of 250 μg·kg−1·h−1. With S(+) ketamine, doses can be reduced to approximately 70% of the dose of racemic ketamine when continuously administered; its use ends 30 min before wound closure (table 2). It is advisable to administer the first bolus doses or the first 20 min of an infusion under careful monitoring of patient hemodynamic response. With reduced nociception, many patients show declines in blood pressure and heart rate. Further doses are then titrated according to the individual response. Under general anesthesia, less anesthetic will be required when ketamine is used in this manner. After administration of subanesthetic ketamine as suggested, ketamine-treated versus control patients did not show an increase in postoperative adverse psychic effects, sedation, or nausea and vomiting.9–16,18Nevertheless, for premedication, a benzodiazepine such as 3.75–7.5 mg oral midazolam or 5–10 mg oral diazepam has been recommended.19To continue pain relief in the postoperative period, PCA with an analgesic plus ketamine combination may be beneficial (table 2).The addition of ketamine to a local anesthetic or other analgesics in peripheral or neuraxial anesthesia and analgesia improves or prolongs pain relief (level II evidence) (table 3).20–24A decrease in drug-related side effects (sedation, pruritus, or adverse psychological reactions) has also been found, mainly because the required drug doses could be reduced.25,26These effects may relate to blockade of central and peripheral NMDA receptors and/or an antinociceptive action complementary to that of the other drugs used. Central and peripheral sensitization may thus be prevented.Although peripheral human NMDA receptors have been identified1,2and ketamine shows local anesthetic-like properties, its peripheral effects at small doses (<0.15 mg/kg) do not provide profound local analgesia when used alone.27At neuraxial sites, ketamine exerts analgesia when used as a sole agent at higher doses, but its utility is limited by psychotomimetic reactions, at least in awake patients.28The resorption and uptake of peripheral or neuraxial ketamine has not yet been systematically analyzed. Based on data from epidural and caudal use, ketamine gains rapid access to the systemic circulation with high bioavailability (level III evidence).29–31After preoperative use in children, caudal S(+) ketamine reduced postoperative pain better than intramuscular29or intravenous S(+) ketamine.30As plasma concentrations are mostly similar after caudal and intramuscular ketamine,29this benefit likely resulted from neuroaxial rather than systemic action. When 0.5 mg/kg epidural versus 0.5 mg/kg intravenous racemic ketamine were compared in adults undergoing gastrectomy, less postoperative pain was also found after epidural use.31Higher plasma concentrations and a longer elimination half-life but decreased maximum plasma concentrations were reported for 48 h after epidural as compared with intravenous ketamine.Trials investigating intraoperative ketamine as an analgesic additive to epidural regimens have reported improved analgesia and a local anesthetic or opioid-sparing effect that lasts into the postoperative period (level II evidence) (table 3).21,22Psychotomimetic effects and postoperative nausea and vomiting were similar in ketamine-treated and control patients. When epidural subanesthetic S(+) ketamine combined with a local anesthetic was injected preincisionally in orthopaedic surgery, beneficial effects over 48 h were reported,22suggesting that a single injection of epidural or local S(+) ketamine may reduce pain beyond the intraoperative period. However, administration of epidural subanesthetic racemic ketamine and morphine before surgical incision did not result in a relevant postoperative effect as compared to use of morphine (although patients treated with ketamine received less intraoperative opioids).32When racemic ketamine was added to a local anesthetic in an interscalene brachial plexus block, no increase in postoperative analgesia was reported.33Thus, the concept that pain prevention requires repeated or continuous intraoperative drug use to counteract ongoing peripheral and spinal noxious stimulation appears to be as valid for regional anesthesia as for general anesthesia.Caudal analgesia added to general anesthesia is an effective regimen for pediatric surgery, but it may be associated with prolonged motor blockade and complications such as systemic toxicity after accidental intravascular injection of local anesthetics or with respiratory depression after opiate use. Studies assessing caudal ketamine have shown efficient analgesia for both intraoperative and postoperative periods (level II evidence) (table 3). Racemic ketamine provided improved pain relief of prolonged duration when added to local anesthetics,24and 0.5–1 mg/kg S(+) ketamine produced analgesia when administered alone or in combination with other anesthetics.23,29,30Postoperatively, no increase in psychotomimetic effects were reported after racemic ketamine ≤0.5 mg/kg or S(+) ketamine ≤1 mg/kg. This may be related to the fact that the children received general anesthesia during the time when systemic drug concentrations were high enough to cause undesired effects. Nevertheless, although there may be advantages over traditionally used caudal anesthetics, further data are needed to assure the safety of caudal ketamine in children at these young ages.Toxic reactions after prolonged neuraxial exposure to racemic ketamine formulations with preservatives (benzethonium chloride or chlorobutanol) have been reported in animal species. A case of spinal neurotoxicity after continuous intrathecal racemic ketamine infused over 3 weeks has been reported.34Despite controversy about the risk-benefit ratio of neuraxial use of ketamine in humans, several facts may help to reach a practical standpoint in this issue. First, chemical cytotoxicity from preservatives unrelated to ketamine has long been known. Only preservative-free preparations must therefore be employed for neuraxial use. Second, the risk of spinal toxicity is generally increased after extended drug exposure. However, dose-response studies in pigs did not reveal neurotoxicity after prolonged epidural preservative-free ketamine,35and patients with terminal cancer pain did not show signs of toxicity after repeated spinal preservative-free subanesthetic ketamine.36Third, physiologic NMDA receptor activity is necessary for cell survival and cerebral function, and rodent data suggest harmful consequences of profound NMDA receptor blockade.37Programmed death occurred in central neurons of the immature rat brain and vacuolization selectively developed in the cingulate and retrosplenial cortex of adult rats after high ketamine doses.37Importantly, coadministration of a gamma-aminobutyric acid receptor agonist prevented these effects. At this time, we think that lack of detailed toxicity data in noncancer patients only allows for preservative-free epidural ketamine use in smaller, subanesthetic doses and within the setting of clinical trials.In addition to inhibition of sensitization in nociceptive pathways, prevention of opiate-related activation of pronociceptive systems and opiate tolerance may be another mechanism of pain prevention by ketamine. The development of rapid tolerance and delayed hyperalgesia after intraoperative and postoperative use of different opioids has been reported in surgical patients.38–40Although the mechanisms that allow ketamine to be an analgesic and opiate-sparing agent after opiate exposure remain poorly understood, two emerging concepts may be important (fig. 2). First, at neuronal synapses, scaffolding proteins such as postsynaptic density protein-95 (PSD-95) and postsynaptic density protein-93 (PSD-93) connect NMDA receptors to the cytoskeleton and to key signaling systems, such as neuronal nitric oxide synthase.1Recent rodent data show obligatory involvement of PSD-95 and PSD-93 in NMDA receptor-mediated neuropathic and chronic pain41and critical roles for PSD-95 and neuronal nitric oxide synthase in opioid tolerance.42Second, in sensitization or developing tolerance, activated protein kinase C and tyrosine kinase cascades facilitate association of key signaling molecules with PSD proteins and NMDA receptors.1,43This activates protein kinases, resulting in NMDA receptor phosphorylation and up-regulation. Enhanced downstream signaling potentiates NMDA function and thus pain sensation. Rat studies in brain ischemia indicate that ketamine decreases injury-triggered increases in interactions between NMDA receptor, PSD-95, and protein kinases. This reduces nitric oxide-related neurotoxicity and finally brain damage.44Thus, a ketamine-induced decrease in unfavourable PSD interaction with protein kinases and pain signaling systems may represent a common mechanism underlying reduced pain sensitization and opiate tolerance phenomena.In the clinical situation, supplementing remifentanil-based anesthesia with preoperative subanesthetic ketamine reduced the need for both intraoperative remifentanil and postoperative opioid analgesia in abdominal surgery.45However, in another study,46a preincisional bolus of 0.5 mg/kg S(+) ketamine followed by an infusion of 120 μg·kg−1·h−1until 2 h after emergence from higher-dose remifentanil anesthesia did not decrease pain after cruciate ligament repair (level II evidence) (table 4). S(+) ketamine, however, was started after general anesthesia was induced with remifentanil. Therefore, it has to be clarified whether ketamine should be administered before or after first opioid use and whether ketamine doses must be adapted to opioid concentrations or the duration of opioid infusion.Perioperative management of opioid-resistant or severe chronic pain is a major clinical problem. Although there has been limited formal research on this topic, a recent study in postoperative surgical patients with morphine-resistant pain found that intravenous subanesthetic ketamine combined with morphine improved pain relief at smaller morphine doses than did morphine alone (table 4).40Moreover, ketamine-treated patients showed better oxygen saturation and greater wakefulness. Ketamine may also be used for pain therapy in the chronic opioid-tolerant patient, especially when other options have failed (level IV evidence).43Although controlled trials are lacking, a “challenge” with subanesthetic ketamine may even be attempted in opioid-addicted patients.47If pain is reduced, ketamine can be titrated to provide analgesia and prevent escalating opioid/analgesic needs. However, two recent reviews on ketamine as an analgesic adjunct in chronic pain patients conclude that further data are needed before routine use can be recommended (level I evidence).48,49After surgery, the combined use of ketamine and an opiate analgesic for intravenous PCA has been tested on general wards and in the intensive care unit. Although several studies reported less pain and decreases in analgesic need and adverse effects such as postoperative nausea and vomiting, sedation, or respiratory insufficiency,15,49–52some did not find remarkable benefits after ketamine (level II evidence) (table 4).53,54Although this has been explained by the nature of the insult (with less painful surgery requiring less postoperative pain therapy), two issues complicate the interpretation of the data. First, most of the drugs applied were chosen on purely empirical grounds with little knowledge of analgesic efficacy of ketamine-opiate combinations. Sometimes dosages were based on body surface area, ketamine bolus applications and background infusions were compared, or doses less than those known to be analgesic were used.54However, the dose of ketamine combined with morphine for PCA depends on the morphine dosing scheme, and interindividual variability in opiate drug requirement is well known. Second, patients were studied with rather global assessment tools such as pain ratings or immediate analgesic need after surgery. To identify long-term effects, parameters such as long-lasting hyperalgesia, patient convalescence, and outcome variables such as length of hospital stay need to be studied. The first issue has been approached with optimization models restricted by side effects for morphine combined with ketamine.51For lumbar spine and hip surgery, the model converged to a morphine:ketamine ratio of 1:1 and a lockout interval of 8 min for postoperative intravenous PCA. Very low pain scores and a negligible incidence of sedation, bradypnea, postoperative nausea and vomiting, pruritus, and psychotomimetic effects suggest that such combinations should be studied further. Nevertheless, after “painful” procedures, an infusion of low-dose (<150 μg·kg−1·h−1) intravenous ketamine combined with PCA appears to be the most promising analgesic technique11,50(level II evidence) (table 4).The most common concerns about ketamine as an analgesic agent are related to its mind-altering effects. This is of special relevance when the compound is to be used in conscious patients. Quiet, relaxed surroundings contribute to a reduced incidence of these side effects, and when ketamine is administered alone, the prophylactic use of a sedative agent such as 3.75–7.5 mg oral midazolam has generally decreased their incidence and severity.19In the setting of postoperative PCA, most trials did not find a difference in adverse psychotomimetic effects (level II evidence).11,50–52,54Effects were dose-dependent and less likely with small doses (<0.15 mg/kg). When ketamine was used as an infusion at less than 10 mg/h, cognitive impairment was negligible.11,50Side effects appear to be similar after S(+) versus racemic ketamine, but volunteers who received equianalgesic doses of both reported less tiredness and impaired cognitive capacity after S(+) ketamine.55In the recovery period, improved mood was found in patients who received intraoperative S(+) ketamine16or propofol and racemic ketamine.56Pain therapy can be improved using intraoperative and postoperative ketamine in a variety of surgical procedures and anesthetic techniques. In particular, the intraoperative use of intravenous subanesthetic ketamine in general anesthesia provides pain prevention in the postoperative period. The most important limitation to the available studies is the lack of evaluation of long-term outcome measures. We do not know whether ketamine use will translate into better recovery profiles or improved functional outcome. There is also insufficient evidence to show a clear benefit of S(+) ketamine as compared with racemic ketamine. For future study, the evaluation of intravenous ketamine as an adjunct to general anesthesia appears to be a priority given the promising results and the ease with which such a regimen could be implemented.

To the Editor, Recent meta-analyses show that lidocaine infusions during open abdominal surgery reduce opioid consumption, postoperative ileus, and hospital length of stay; however, results in other surgeries have been conflicting. We conducted a single-centre double-blind randomized controlled trial to investigate whether intravenous lidocaine for video-assisted thoracoscopic surgery (VATS) would lower postoperative opioid requirements. Secondary outcomes included pain scores and side effects such as nausea, vomiting, pruritis, constipation, and symptoms of lidocaine toxicity, including lightheadedness, tinnitus, oral numbness, arrhythmias, altered mental status, or seizures. This trial is registered at ClinicalTrials.gov NCT01277835. After approval from the Biomedical Research Ethics Board at the University of Saskatchewan on February 3, 2010, informed consent was obtained from adults aged 18-75 yr, American Society of Anesthesiologists physical status I-III, and scheduled for VATS from April 2010 to February 2013. Computer randomization allocated patients into two groups according to a 1:1 ratio. The lidocaine treatment group received a 1.5 mg kg bolus of intravenous lidocaine on induction, followed by an infusion of 3 mg min for patients weighing[70 kg or 2 mg min for patients weighing 70 kg. The placebo group received a normal saline bolus and an infusion to simulate the study drug. Anesthetic induction was standardized. Postanesthesia care unit (PACU) nurses administered morphine to keep the patients’ numerical rating scale 4. All surgical team members (anesthesiologist, surgeon, and nurses) were blinded to the treatment groups. Forty-eight patients were enrolled in the study. Complete data were available for 36 patients (19 lidocaine group; 17 control group) in this per-protocol analysis. Reasons for attrition of 12 patients included: surgical procedure converted to an open procedure (seven patients), failure to connect the lidocaine infusion (one), no data collected on the ward (one), and personal reasons (three). Demographic characteristics were similar between groups (Table). The Table also includes a summary of all study results with a comparison between groups for up to 48 hr postoperatively. We found no statistically significant difference in intraoperative fentanyl use or morphine use in recovery. Postoperative morphine requirements and pain scores were low in both groups and not significantly different at any time. There was no difference in occurrence of side effects, most of which were opioid related: nausea, constipation, urinary retention, and pruritis. One patient in the control group experienced respiratory depression not requiring invasive ventilation. In the PACU, one patient experienced blurry vision and lightheadedness and another experienced hypotension, both in the control group. There were no symptoms of lidocaine toxicity. This trial suggests that an infusion of intravenous lidocaine during VATS procedures does not reduce opioid consumption in the operating room or postoperatively and does not reduce postoperative pain scores. This may be due in part to the relatively low consumption of morphine noted among our patients. Postoperative morphine consumption among VATS M. Slovack, MD (&) B. Taylor, MD D. Ong, MD Department of Anesthesiology, Royal University Hospital, Saskatoon, SK, Canada e-mail: mark.slovack@usask.ca

Background: Transversus abdominis plane (TAP) block is a relatively newer block that provides analgesia to the parietal peritoneum, skin and muscles of the anterior abdominal wall. Aims: To determine the effectiveness of the TAP block over wound infiltration for hernia repair. Settings and Design: Randomized, double-blinded, prospective study in an academic teaching hospital. Methods: Sixty patients were divided into two groups of 30 each. In Group T, patients received ultrasound-guided TAP block for inguinal hernia repair whereas in Group I, local anesthetic infiltration at the wound site was done. Primary outcome measure was pain relief as assessed by a numeric rating scale (NRS) whereas secondary outcome measures were duration (from the time at which TAP block or local anesthetic infiltration is given to the time at which patient first requests for rescue analgesic) of post-operative analgesia, patient satisfaction score, and complications, if any. Results: Mean NRS score at 0hr for a group I was 0.88±0.74 and for group T was 0.68±0.70 with a p-value of 0.28 and the mean NRS score at 24hr for the group I was 4.47±0.66 and for group T was 4.54±0.62 with a p-value of 0.68 but at 2hr, 6hr and 12hr, the NRS was significantly more in group I (p &lt; 0.05). Mean time of 1st analgesic request in group I was 403.73 minutes as compared to group T where it was 711.33 mins (P&lt;0.001). The post-operative nausea and vomiting (PONV) and sedation in group I was significantly more than group T. Conclusion: Ultrasound-guided TAP block provides better postoperative analgesia both in quality and duration. TAP block reduces the opioid demand and opioid-related side effects like sedation and postoperative nausea vomiting and thus, improves overall patient satisfaction.

PurposeNon-intubated video-assisted thoracic surgery (NIVATS) reduces airway trauma but may lead to postoperative hyperalgesia and opioid dependence, contradicting enhanced recovery after surgery (ERAS) principles. We hypothesized that combining low-dose esketamine with a paravertebral block (PVB) may mitigate hyperalgesia, decrease opioid requirements, and improve recovery quality in NIVATS.Patients and MethodsThis prospective single-center, double-blind randomized controlled trial (RCT) enrolled 82 patients undergoing uniportal NIVATS. Patients were randomized into two groups: esketamine (0.25 mg/kg pre-induction + 0.15 mg/kg/h intraoperatively) and control. Both groups received ultrasound-guided T4 and T6 PVB (with 0.375% ropivacaine). The primary outcome was mechanical pain threshold (MPT; central/peripheral), quantified preoperatively and at 0.5–48 h postoperatively using pressure algometry after laryngeal mask airway (LMA) removal. Secondary outcomes included quality of recovery-40 (QoR-40) scores, intraoperative sufentanil/norepinephrine use, postoperative rescue analgesia use, and other related complications.ResultsCompared to controls, the esketamine group exhibited significantly higher MPT at 6 h postoperatively (central: 2.77 ± 0.80 vs 2.17 ± 0.59 kgf/cm², P < 0.001; and peripheral: 2.95 ± 0.89 vs 2.17 ± 0.62 kgf/cm², P < 0.001). It also showed markedly improved QoR-40 scores (POD1: 182.3 ± 6.0 vs 175.8 ± 7.2, P < 0.001; and POD3: 190.3 ± 2.9 vs 186.8 ± 3.6, P < 0.001). Compared to controls, the esketamine group also showed significantly lower intraoperative sufentanil consumption (median 5.0 vs 17.5 μg) and norepinephrine requirement (219.1 ± 124.7 vs 393.7 ± 182.3 μg), as well as postoperative rescue analgesia use (P < 0.05). Except for postoperative nausea and vomiting (PONV) incidence (P < 0.05), both groups had similar profiles in other adverse events.ConclusionLow-dose esketamine combined with PVB attenuates postoperative hyperalgesia, reduces intraoperative opioid use by 71.4%, and enhances recovery in NIVATS, offering a clinically effective opioid-sparing strategy for ERAS protocols.

Providing adequate analgesia perioperatively during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation can be a challenge. The objective of our study was to assess the efficacy and safety of the erector spinae plane (ESP) block technique in providing analgesia and minimizing the risk of opioid use in high-risk patient populations. We enrolled consecutive patients >18 years of age undergoing S-ICD implantation from February 2020 to February 2022 at our center prospectively. Patients were randomly assigned to receive the ESP block or traditional wound infiltration. A total of 24 patients were enrolled, including 13 patients randomized to ESP block and 11 patients as controls who received only wound infiltration. The primary outcome assessed was the overall use of perioperative analgesic medications in the ESP block group versus the surgical wound infiltration group. A significant reduction in intraoperative fentanyl use was observed [median ([interquartile range]) in the ESP block group (0 [0-50] μg) compared to the wound infiltration block group (75 [50-100] μg) (P = .001). The overall postoperative day (POD) 0 fentanyl use was also significantly decreased (75 [50-100] μg) in the ESP block group compared to the surgical wound infiltration group (100 [87.5-150] μg) (P = .049). There was also a trend of decreased POD 0 oxycodone-acetaminophen use. Finally, the number of days to discharge was less in the ESP block group. These results indicate that ESP block is an innovative, safe, and effective technique that decreases intraoperative and postoperative opioid consumption and may be a useful adjunct pain-management technique in these high-risk patients. Larger studies are needed to further validate its use.

Knowledge of postoperative nausea and vomiting (PONV) risk factors allows anesthesiologists to optimize the use of prophylactic regimens. Modern PONV risk research began in the 1990s with publication of studies using logistic regression analysis to simultaneously identify multiple independent PONV predictors and publication of meta-analyses and systematic reviews. This literature shows that female gender post-puberty, nonsmoking status, history of PONV or motion sickness, childhood after infancy and younger adulthood, increasing duration of surgery, and use of volatile anesthetics, nitrous oxide, large-dose neostigmine, or intraoperative or postoperative opioids are well established PONV risk factors. Possible risk factors include history of migraine, history of PONV or motion sickness in a child's parent or sibling, better ASA physical status, intense preoperative anxiety, certain ethnicities or surgery types, decreased perioperative fluids, crystalloid versus colloid administration, increasing duration of anesthesia, general versus regional anesthesia or sedation, balanced versus total IV anesthesia, and use of longer-acting versus shorter-acting opioids. Early-phase menstruation, obesity and lack of supplemental oxygen are disproved risk factors. Current risk scoring systems have approximately 55%-80% accuracy in predicting which patient groups will suffer PONV. Further research examining genetic and under-investigated clinical patient characteristics as potential risk factors, and involving outpatients and children, should improve predictive systems.

Post-operative nausea and vomiting (PONV) is an event of multifactorial origin with an incidence of 30% in the general population. Opioids such as fentanyl are being used as adjuvant to local anesthetic for its antiemetic effect. In this context, with this study we aimed to evaluate the impact of spinal fentanyl as an adjuvant on the incidence of PONV compared with a placebo, and shivering. A systematic search of randomized controlled trials that evaluated the use of spinal fentanyl in the prevention of PONV and shivering was conducted in different databases, of which 32 studies met the inclusion criteria. A total of 2116 patients scheduled for various surgeries, including cesarean section, orthopedic surgery in the lower limb, hysterectomy, and transurethral resection of the prostate, were included in the final analysis. The meta-analysis estimated the relative risk of incidence of PONV in the first 24 hours after surgery and secondary outcomes included the shivering symptom. The use of intrathecal fentanyl was associated with lower incidence of PONV, but not statistically significant when compared to the placebo (RR: 0.74 CI95%: 0.55-1.01 P = 0.06). Subgroup analysis showed a statistically significant reduction in PONV incidences with lower doses between 10 and 15 μg (RR: 0.44 CI95%: 0.35–0.55 P < 0.00001, I2 = 0%) but not with higher doses 20–25 μg. Secondary outcomes showed a decrease in incidence with the use of fentanyl vs the placebo (RR: 0.49, CI95% 0.33-0.72 P = 0.0003). Current evidence shows that the use of spinal fentanyl decreases the incidence of PONV, an effect favored using low doses.

Few data are available on TAP block in laparoscopic colorectal surgery and ERAS program. The aim of this prospective study was to evaluate local wound infiltration plus TAP block compared to local wound infiltration in the management of postoperative pain, nausea and vomiting, ileus and use of opioids in the context of laparoscopic colorectal surgery and ERAS program. From March 2014 to March 2015, 48 patients were treated by laparoscopic resection and ERAS program for colorectal cancer and diverticular disease at the Division of General and Hepatobiliary Surgery, University of Verona Hospital Trust. Among these, 24 patients received local wound infiltration plus TAP block (TAP block group) and 24 patients received local wound infiltration (control group). No differences were observed in baseline patient characteristics, clinical variables and surgical procedures between the two groups. Local wound infiltration plus TAP block allowed to achieve pain control despite a reduced use of opioid analgesics (P=0.009). The adoption of TAP block resulted beneficial on the prevention of postoperative nausea (P=0.002) and improvement of essential outcomes of ERAS program as recovery of bowel function (P=0.005), urinary catheter removal (P=0.003) and capability to tolerate oral diet (P=0.027). TAP block plus local wound infiltration in the setting of laparoscopic colorectal surgery and ERAS program guarantees a reduced use of opioid analgesics and good pain control allowing the improvement of essential items of enhanced recovery pathways.

Objective To observe the effects of dexamethasone on ultrasound-guided transversus abdominis plane block (TAPB) for laparoscopic-assisted radical operation of colorectal cancer. Methods Ninety patients scheduled laparoscopic-assisted surgeries for colorectal cancer were randomly divided into 3 groups. Patients in group C only received general anesthesia. Patients in group T were given ultrasound-guided TAPB after the induction of anesthesia. Patients in group TD were administrated with 10 mg dexamethasone intravenously before the induction of anesthesia, and then received TAPB. Pethidine was given when numerical rating scale(NRS) pain score was higher than 3, a sign for the requirement of postoperative rescue-analgesia. In this study, we assessed the total consumption of remifentanil and sevoflurane during operation. NRS pain scores were assessed at 2, 6, 12, 24, 48 h after the operation. The first-time administration and consumption of pethidine were recorded. We also recorded incidence of adverse reactions. Results Compared with group C, the consumption of remifentanil and postoperative NRS pain scores at all time points were significantly less in group T and group TD(P<0.05), the first-time administration of pethidine was delayed and the consumption of pethidine was also less(P<0.05) in group T and TD. Incidence of postoperative nausea and vomiting(PONV) in group T and TD was declined(P<0.05). Compared with group T, group TD had lower NRS scores at 6, 12 h after the operation, delayed first-time administration of pethidine, and less consumption of pethidine(P<0.05). Conclusions TAPB combined with dexamethasone intravenously will prolong the time of blockade. Reduction of the total consumption of opioids in laparoscopic-assisted surgery for colorectal cancer was also significant. Key words: Dexamethasone; Transversus abdominis plane block; Ropivacaine; Therapeutic laparoscope; Colorectal cancer

BackgroundPostoperative nausea and vomiting (PONV) is significantly associated with intraoperative opioid use. Oliceridine, a μ-opioid receptor agonist with G protein bias, exhibits fewer opioid-related adverse events (ORAEs) than morphine. This study aims to evaluate the effect of oliceridine versus fentanyl on the incidence of PONV in female patients undergoing laparoscopic cholecystectomy.MethodsThis is a single-center, randomized controlled trial conducted at Changshu No. 2 People's Hospital in China. A total of 228 female patients scheduled for elective laparoscopic cholecystectomy will be enrolled in this trial and randomly assigned in a 1:1 ratio to receive either oliceridine (Group O) or fentanyl (Group F) for intraoperative analgesia. The primary endpoint is the incidence of PONV during the first 24 h postoperatively. The secondary endpoints consist of the severity and timing of the initial occurrence of PONV, the requirement for antiemetics and rescue analgesia, postoperative pain assessments, time to first flatus and extubation, postoperative sleep quality, intraoperative consumption of anesthetics and vasopressors, and perioperative adverse effects.DiscussionWe hypothesize that oliceridine may offer effective analgesia and a lower incidence of PONV than fentanyl in intraoperative pain management for this high-risk group. The findings may provide valuable insights into optimizing perioperative pain management strategies and enhancing patient recovery.Trial registrationChinese Clinical Trial Registry ChiCTR2500096538. Registered on 26 January 2025

Study objective The purpose of this study is to investigate the analgesic efficacy of ultrasound-guided fascial plane blocks (FPBs) versus local infiltration in patients undergoing laparoscopic non-donor nephrectomy. This study specifically compares the efficacy of FPBs with liposomal bupivacaine (LB) versus FPBs with dexamethasone sodium phosphate (DXP) and methylprednisolone acetate (MPA) versus surgical site local anesthetic infiltration without FPBs. Design This is a retrospective cohort study conducted over a five-year period (January 2018-December 2022). Setting The study was conducted in a tertiary care, academic, multi-hospital healthcare system. Participants Patients who underwent elective radical or partial laparoscopic non-donor nephrectomy were included in the study. Intervention Patients either received preoperative FPBs without intraoperative surgical site local anesthetic infiltration or received surgical site local anesthetic infiltration without FPBs (n = 141) at participating hospitals. Measurements The primary endpoint of this study was postoperative opioid use, measured as oral milligram morphine equivalents (MME). Secondary endpoints included postoperative pain scores, length of hospital stays, and significant adverse events within 30 days. The impact of medications utilized in FPBs was determined by univariate and multivariable analyses with covariates balancing propensity score weighting. Main results Patients undergoing non-donor laparoscopic radical or partial nephrectomy who received FPBs with bupivacaine or ropivacaine plus glucocorticoids DXP and MPA were more likely to be opioid-free 24-48 hours postoperatively compared to those who received FPBs with LB or surgical site local anesthetic infiltration without FPBs (40.5% vs. 30% vs. 13.9%, respectively; p = 0.017). Patients who received FPBs with glucocorticoids also reported the lowest pain scores at rest and with activity 0-12 hours postoperatively as compared to patients who received LB or local infiltration (p = 0.006 and p = 0.014, respectively). Additionally, patients who received FPBs with glucocorticoids received over 30% fewer opioids during the first 48 hours postoperatively compared to patients who received surgical site local anesthetic infiltration alone (30 MME vs. 44 MME, respectively). However, there was no significant difference in total opioid use during the first 48 hours postoperatively between patients who received FPBs with bupivacaine plus glucocorticoids and those who received FPBs with bupivacaine plus LB (mean ratio: 0.91, (95% CI: 0.05 ~ 15.97); p = 0.948). There was also no difference in the length of hospital stays or rate of adverse events between the groups. Conclusion Perioperative FPBs for non-donor laparoscopic nephrectomy using glucocorticoids as an adjuvant to long-acting local anesthetics may decrease postoperative opioid use and reduce pain scores as compared to FPBs with LB or surgical site local anesthetic infiltration. Bupivacaine or ropivacaine combined with DXP and MPA is a safe and effective alternative to LB for FPBs in laparoscopic nephrectomy.

In clinical practice, using different opioid analgesics is common during the induction and maintenance of general anesthesia and for postoperative analgesia. However, if the opioid analgesic could be limited to a single drug, we hypothesized that the risk of adverse drug interactions could be reduced, with fewer adverse effects. We examined the use of oxycodone as a single opioid in a well-defined cohort of orthopedic patients undergoing general anesthesia. In this retrolective, monocentric investigation, we reviewed data from 83 patients who underwent general anesthesia and received intravenous oxycodone as the sole analgesic (0.075 mg/kg during induction and 0.05 mg/kg during maintenance). The use of oxycodone during general anesthesia and the postoperative pain scores were recorded. Safety was evaluated by the measurement of hemodynamic changes (blood pressure, heart rate), the detection of pathologic changes in the electrocardiogram, changes of the peripheral oxygen saturation, and by the assessment of adverse effects. There was no significant change in peripheral oxygen saturation or the electrocardiogram during or while recovering from general anesthesia. Heart rate changed only slightly from reversal to recovery (73.3/min versus 78.3/min, p < 0.05) and from prior intubation to recovery (72.5/min versus 78.3/min, p < 0.05). Systolic and diastolic blood pressure did not change significantly from the time points "after intubation" to "after incision," and "during recovery." Fifty-nine percent (n = 49) of patients' records revealed pain scores with a maximum of 3 on a numeric rating scale (NRS) of 0 to10 during the postoperative period. In 45 percent of patients (n = 37), further analgesics such as acetaminophen, dipyrone, or additional doses of oxycodone were used. No severe adverse events were recorded. According to data from 93 percent of patients (n = 77), nausea scores were less than 3 on a NRS of 0 to 10. Oxycodone can be used as the sole opioid in orthopedic surgery with good intra- and postoperative efficacy and safety; ie, without clinically relevant changes in hemodynamic and respiratory parameters.

Pediatric craniofacial reconstruction surgery is associated with significant perioperative analgesic requirements. As dexmedetomidine mediates central nervous system sympathetic activity and pain modulation, its intraoperative use could be beneficial in craniofacial surgery. We hypothesized that intraoperative administration of dexmedetomidine in children undergoing craniofacial reconstructive surgery would result in reduced opioid requirements, pain, sedation scores, and opioid-induced side effects compared to patients who did not receive dexmedetomidine. All patients who underwent craniofacial reconstructive surgery at our institution from July 2013 to June 2017 were retrospectively evaluated. The primary outcome measure was mean postoperative morphine equivalent requirements. Secondary outcome measures included incidence of opioid-related side effects, pain scores, and hospital length of stay. Thirty-nine patients received dexmedetomidine intraoperatively while 41 patients did not. There was no difference in postoperative opioid requirements or pain scores between the two cohorts. However, patients who received higher doses of dexmedetomidine (4.7 mcg/kg) intraoperatively exhibited significantly lower rescue medication requirements for nausea and vomiting postoperatively. Contrary to the hypothesis, dexmedetomidine was not associated with reduced postoperative opioid requirements or pain scores in children undergoing craniofacial reconstructive surgery. However, our findings do suggest that dexmedetomidine may be beneficial in reducing side effects such as postoperative nausea and vomiting. A randomized controlled trial would be necessary to verify these findings.