General Anesthetic Research Articles

Transabdominal motor evoked potential neuromonitoring of lumbosacral spine surgery

BACKGROUND CONTEXTTranscranial Motor Evoked Potentials (TcMEPs) can improve intraoperative detection of femoral plexus and nerve root injury during lumbosacral spine surgery. However, even under ideal conditions, TcMEPs are not completely free of false-positive alerts due to the immobilizing effect of general anesthetics, especially in the proximal musculature. The application of transcutaneous stimulation to activate ventral nerve roots directly at the level of the conus medularis (bypassing the brain and spinal cord) has emerged as a method to potentially monitor the motor component of the femoral plexus and lumbosacral nerves free from the blunting effects of general anesthesia. PURPOSETo evaluate the reliability and efficacy of transabdominal motor evoked potentials (TaMEPs) compared to TcMEPs during lumbosacral spine procedures. DESIGNWe present the findings of a single-center 12-month retrospective experience of all lumbosacral spine surgeries utilizing multimodality intraoperative neuromonitoring (IONM) consisting of TcMEPs, TaMEPs, somatosensory evoked potentials (SSEPs), electromyography (EMG), and electroencephalography. PATIENT SAMPLETwo hundred and twenty patients having one, or a combination of lumbosacral spine procedures, including anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), posterior spinal fusion (PSF), and/or transforaminal lumbar interbody fusion (TLIF). OUTCOME MEASURESIntraoperative neuromonitoring data was correlated to immediate postoperative neurologic examinations and chart review. METHODSBaseline reliability, false positive rate, true positive rate, false negative rate, area under the curve at baseline and at alerts, and detection of preoperative deficits of TcMEPs and TaMEPs were compared and analyzed for statistical significance. The relationship between transcutaneous stimulation voltage level and patient BMI was also examined. RESULTSTaMEPs were significantly more reliable than TcMEPs in all muscles except abductor hallucis. Of the 27 false positive alerts, 24 were TcMEPs alone, and 3 were TaMEPs alone. Of the 19 true positives, none were detected by TcMEPs alone, 3 were detected by TaMEPs alone (TcMEPs were not present), and the remaining 16 true positives involved TaMEPs and TcMEPs. TaMEPs had a significantly larger area under the curve (AUC) at baseline than TcMEPs in all muscles except abductor hallucis. The percent decrease in TcMEP and TaMEP AUC during LLIF alerts was not significantly different. Both TcMEPs and TaMEPs reflected three preexisting motor deficits. Patient BMI and TaMEP stimulation intensity were found to be moderately positively correlated. CONCLUSIONSThese findings demonstrate the high reliability and predictability of TaMEPs and the potential added value when TaMEPs are incorporated into multimodality IONM during lumbosacral spine surgery.

Comparative brain-wide mapping of ketamine- and isoflurane-activated nuclei and functional networks in the mouse brain.

Ketamine (KET) and isoflurane (ISO) are two widely used general anesthetics, yet their distinct and shared neurophysiological mechanisms remain elusive. In this study, we conducted a comparative analysis of the effects of KET and ISO on c-Fos expression across the mouse brain, utilizing hierarchical clustering and c-Fos-based functional network analysis to evaluate the responses of individual brain regions to each anesthetic. Our findings reveal that KET activates a wide range of brain regions, notably in the cortical and subcortical nuclei involved in sensory, motor, emotional, and reward processing, with the temporal association areas (TEa) as a strong hub, suggesting a top-down mechanism affecting consciousness by primarily targeting higher order cortical networks. In contrast, ISO predominantly influences brain regions in the hypothalamus, impacting neuroendocrine control, autonomic function, and homeostasis, with the locus coeruleus (LC) as a connector hub, indicating a bottom-up mechanism in anesthetic-induced unconsciousness. KET and ISO both activate brain areas involved in sensory processing, memory and cognition, reward and motivation, as well as autonomic and homeostatic control, highlighting their shared effects on various neural pathways. In conclusion, our results highlight the distinct but overlapping effects of KET and ISO, enriching our understanding of the mechanisms underlying general anesthesia.

Comparative brain-wide mapping of ketamine- and isoflurane-activated nuclei and functional networks in the mouse brain

Ketamine (KET) and isoflurane (ISO) are two widely used general anesthetics, yet their distinct and shared neurophysiological mechanisms remain elusive. In this study, we conducted a comparative analysis of the effects of KET and ISO on c-Fos expression across the mouse brain, utilizing hierarchical clustering and c-Fos-based functional network analysis to evaluate the responses of individual brain regions to each anesthetic. Our findings reveal that KET activates a wide range of brain regions, notably in the cortical and subcortical nuclei involved in sensory, motor, emotional, and reward processing, with the temporal association areas (TEa) as a strong hub, suggesting a top-down mechanism affecting consciousness by primarily targeting higher order cortical networks. In contrast, ISO predominantly influences brain regions in the hypothalamus, impacting neuroendocrine control, autonomic function, and homeostasis, with the locus coeruleus (LC) as a connector hub, indicating a bottom-up mechanism in anesthetic-induced unconsciousness. KET and ISO both activate brain areas involved in sensory processing, memory and cognition, reward and motivation, as well as autonomic and homeostatic control, highlighting their shared effects on various neural pathways. In conclusion, our results highlight the distinct but overlapping effects of KET and ISO, enriching our understanding of the mechanisms underlying general anesthesia.

Ferritinophagy-Mediated Hippocampus Ferroptosis is Involved in Cognitive Impairment in Immature Rats Induced by Hypoxia Combined with Propofol.

Propofol is a clinically common intravenous general anesthetic and is widely used for anesthesia induction, maintenance and intensive care unit (ICU) sedation in children. Hypoxemia is a common perioperative complication. In clinical work, we found that children with hypoxemia who received propofol anesthesia experienced significant postoperative cognitive changes. To explore the causes of this phenomenon, we conducted the study. In this study, our in vivo experiments found that immature rats exposed to hypoxia combined with propofol (HCWP) could develop cognitive impairment. We performed the RNA-seq analysis of its hippocampal tissues and found that autophagy and ferroptosis may play a role in our model. Next, we verified the participation of the two modes of death by detecting the expression of autophagy-related indexes Sequestosome 1 (SQSTM1) and Beclin1, and ferroptosis-related indicators Fe2+, reactive oxygen species (ROS) and glutathione peroxidase 4 (GPX4). Meanwhile, we found that ferrostatin-1 (Fer-1), an inhibitor of ferroptosis, could improve cognitive impairment in immature rats caused by HCWP. In addition, we found that nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy, which acted as a key junction between autophagy and ferroptosis, was also involved. Finally, our in vitro experiments concluded that autophagy activation was an upstream factor in HCWP-induced hippocampus ferroptosis through the intervention of autophagy inhibitor 3-methyladenine (3-MA). Our study was expected to provide an attractive therapeutic target for cognitive impairment that occurred after HCWP exposures.

Literature Review: Gambaran Monitoring Kedalaman Anestesi Pada Anestesi Umum

The term "depth of anesthesia" refers to the extent to which a general anesthetic agent anesthetizes the central nervous system with a specific concentration of force at the time the drug is administered. The depth level of anesthesia plays an important role in determining surgical complications, and it is very important to keep the depth level of anesthesia under control for the operation to be successful. The purpose of this study is to determine the Monitoring Picture of Anesthesia Depth in General Anesthesia. The literature search will be conducted between 2018 and 2023. The methodof journals and scientific articles contained in this study are national and international journals that have been accounted for their validity. Sources of information obtained from databases are Google Scholar, Science Direct, and PubMed. Anesthesia depth monitoring with the most popular modern technique in practice is the Bixpectral Index Score (BIS) monitor. Anesthesia depth monitoring using BIS is more accurate than traditional anesthesia depth monitoring. Objective assessment of the depth of sedation can use the BIS tool that provides the best prediction of the patient's degree of consciousness to] prevent the patient from waking up and remember actions, drug additions, and wake predictions more accurately by looking at changes in brain electrical activity depicted through EEG

Long-term Survival after Volatile or Propofol General Anesthesia for Bladder Cancer Surgery: A Retrospective National Registry Cohort Study.

Prospective interventional trials and retrospective observational analyses provide conflicting evidence regarding the relationship between propofol versus inhaled volatile general anesthesia and long-term survival after cancer surgery. Specifically, bladder cancer surgery lacks prospective clinical trial evidence. Data on bladder cancer surgery performed under general anesthesia between 2014 and 2021 from the National Quality Registry for Urinary Tract and Bladder Cancer and the Swedish Perioperative Registry were record-linked. Overall survival was compared between patients receiving propofol or inhaled volatile for anesthesia maintenance. The minimum clinically important difference was defined as a 5-percentage point difference in 5-yr survival. Of 7,571 subjects, 4,519 (59.7%) received an inhaled volatile anesthetic, and 3,052 (40.3%) received propofol for general anesthesia maintenance. The two groups were quite similar in most respects but differed in American Society of Anesthesiologists Physical Status and tumor stage. Propensity score matching was used to address treatment bias. Survival did not differ during follow-up (median, 45 months [interquartile range, 33 to 62 months]) in the full unmatched cohort nor after 1:1 propensity score matching (3,052 matched pairs). The Kaplan-Meier adjusted 5-yr survival rates in the matched cohort were 898 of 3,052, 67.5% (65.6 to 69.3%) for propofol and 852 of 3,052, 68.5% (66.7 to 70.4%) for inhaled volatile general anesthesia, respectively (hazard ratio, 1.05 [95% CI, 0.96 to 1.15]; P = 0.332). A sensitivity analysis restricted to 1,766 propensity score-matched pairs of patients who received only one general anesthetic during the study period did not demonstrate a difference in survival; Kaplan-Meier adjusted 5-yr survival rates were 521 of 1,766, 67.1% (64.7 to 69.7%) and 482 of 1,766, 68.9% (66.5 to 71.4%) for propofol and inhaled volatile general anesthesia, respectively (hazard ratio, 1.09 [95% CI, 0.97 to 1.23]; P = 0.139). Among patients undergoing bladder cancer surgery under general anesthesia, there was no statistically significant difference in long-term overall survival associated with the choice of propofol or an inhaled volatile maintenance.

A Common Neuronal Ensemble in the Lateral Habenula Regulates Ciprofol Anesthesia in Mice.

General anesthetics were first used over 170 years ago; however, the mechanisms of how general anesthetics induce loss of consciousness (LOC) remain unclear. Ciprofol, a novel intravenous anesthetic, has been developed by incorporating cyclopropyl into the chemical structure of propofol. This modification offers the benefits of rapid onset and minimal injection pain. Recent studies have revealed that the glutamatergic neurons of the lateral habenula (LHb) play a crucial role in modulating the LOC induced by propofol and sevoflurane. Nevertheless, the specific involvement of LHb in the anesthetic effects of ciprofol remains uncertain. Here, using targeted recombination in active populations (TRAP) combined with electroencephalogram/electromyography recordings and the righting reflex behavioral test, our study revealed that intravenous infusion of ciprofol for 1 h could lead to the induction of c-Fos expression in the LHb in mice. The combination of TRAP and gene ablation, aimed at selectively ablating ciprofol-activated neurons in the LHb, has been shown to facilitate the emergence of ciprofol anesthesia and decrease the proportion of delta waves during the emergence phase. Chemogenetic inhibition of these neurons produced a comparable effect, whereas chemogenetic activation resulted in the opposite outcome. Chemogenetic activation of ciprofol-activated neurons in the LHb delays the emergence of anesthesia and induces a deep hypnotic state during the emergence phase. Taken together, our findings suggest that LHb ciprofol-activated neurons modulate the state of consciousness and could potentially be targeted to manipulate consciousness during ciprofol anesthesia.

Acute and Persistent Postoperative Functional Decline in Children with Severe Neurological Impairment: A Qualitative, Exploratory Study.

Children with severe neurologic impairment (SNI) regularly require major surgery to manage their underlying conditions. Anecdotal evidence suggests that children with SNI experience unexpected and persistent postoperative functional changes long after the postoperative recovery period; however, evidence from the perspective of caregivers is limited. The purpose of the study was to explore the functional postoperative recovery process for children with SNI. Eligible participants were English-speaking caregivers of children with SNI between 6 months and 17 years who were nonverbal, Gross Motor Function Classification Scale level IV/V, and who had surgery/procedure requiring general anesthetic at a tertiary children's hospital between 2012 and 2022. Demographic and basic health information were collected via surveys and corroborated by a review of the child's electronic health record. Semi-structured interviews were conducted and a thematic content analysis was used to formulate results. Data from 12 primary caregiver interviews revealed four main themes: (1) functional changes and complications in the child; (2) feeling unprepared; (3) perioperative support; and (4) changes to caregiver roles. Postoperative functional decline in children with SNI was prevalent in our sample. Providing pre-operative information to families to describe this phenomenon should be a regular part of family-informed care.

Safety and efficacy comparison of remimazolam and propofol for intravenous anesthesia during gastroenteroscopic surgery of older patients: A meta-analysis

BACKGROUND Remimazolam is characterized by rapid action and inactive metabolites. It is used as the general anesthetic for many clinical surgeries. In this study, we performed a meta-analysis to evaluate whether remimazolam is superior to propofol for gastroenteroscopy in older patients. AIM To compare the adverse events and efficacy of remimazolam and propofol during gastroenteroscopy in older adults. METHODS The PubMed, Web of Science, the Cochrane Library databases were queried for the relevant key words "remimazolam,” "and propofol,” "and gastrointestinal endoscopy or gastroscopy.” The search scope was "Title and Abstract,” and the search was limited to human studies and publications in English. Seven studies wherein remimazolam and propofol were compared were included for the meta-analysis. RESULTS We selected seven randomized controlled trials involving 1445 cases for the analysis. Remimazolam reduced the hypotension (relative risk, RR = 0.44, 95%CI: 0.29-0.66, P = 0.000), respiratory depression (RR = 0.46, 95%CI: 0.30-0.70, P = 0.000), injection pain (RR = 0.12, 95%CI: 0.05-0.25, P = 0.000), bradycardia (RR = 0.37, 95%CI: 0.24-0.58, P = 0.000), and time to discharge [weighted mean difference (WMD) = -0.58, 95%CI: -0.97 to -0.18, P = 0.005], compared to those after propofol administration. No obvious differences were observed for postoperative nausea and vomiting (RR = 1.09, 95%CI: 0.97-1.24, P = 0.151), dizziness (RR = 0.77, 95%CI: 0.43-1.36, P = 0.361), successful sedation rate (RR = 0.96, 95%CI: 0.93-1.00, P = 0.083), or the time to become fully alert (WMD = 0.00, 95%CI: -1.08-1.08, P = 0.998). CONCLUSION Remimazolam appears to be safer than propofol for gastroenteroscopy in older adults. However, further studies are required to confirm these findings.

Etomidate enhances cerebellar CF-PC synaptic plasticity through CB1 receptor/PKA cascade in vitro in mice

Etomidate (ET) is a widely used intravenous imidazole general anesthetic, which depresses the cerebellar neuronal activity by modulating various receptors activity and synaptic transmission. In this study, we investigated the effects of ET on the cerebellar climbing fiber-Purkinje cells (CF-PC) plasticity in vitro in mice using whole-cell recording technique and pharmacological methods. Our results demonstrated that CF tetanic stimulation produced a mGluR1-dependent long-term depression (LTD) of CF-PC excitatory postsynaptic currents (EPSCs), which was enhanced by bath application of ET (10 µM). Blockade of mGluR1 receptor with JNJ16259685, ET triggered the tetanic stimulation to induce a CF-PC LTD accompanied with an increase in paired-pulse ratio (PPR). The ET-triggered CF-PC LTD was abolished by extracellular administration of an N-methyl-(D)-aspartate (NMDA) receptor antagonist, D-APV, as well as by intracellular blockade of NMDA receptors activity with MK801. Furthermore, blocking cannabinoids 1 (CB1) receptor with AM251 or chelating intracellular Ca2+ with BAPTA, ET failed to trigger the CF-PC LTD. Moreover, the ET-triggered CF-PC LTD was abolished by inhibition of protein kinase A (PKA), but not by inhibition of protein kinase C inhibiter. The present results suggest that ET acts on postsynaptic NMDA receptor resulting in an enhancement of the cerebellar CF-PC LTD through CB1 receptor/PKA cascade in vitro in mice. These results provide new evidence and possible mechanism for ET anesthesia to affect motor learning and motor coordination by regulating cerebellar CF-PC LTD.

Cellular Mechanisms Associated with Neurodevelopmental Alterations Produced by General Anesthetics

: There is concern about neurodevelopmental disturbances associated with exposure to general anesthesia during early childhood. In 2016, the U.S. Food and Drug Administration released a safety alert regarding the use of gamma-aminobutyric acid (GABA) agonists and N-methyl-D-aspartate (NMDA) receptor antagonists in pediatric anesthesia, warning about the risks of their use during the last trimester of pregnancy and in children under 3 years for neurodevelopment. Animal and in vitro studies demonstrate worrisome morphological and functional alterations in young neurons and glia induced by different anesthetic drugs. These drugs can induce changes in various neuronal transmission systems, alter dendritic growth and brain connectivity, and initiate processes leading to cell demise, such as aberrant cell cycle reentry, mitochondrial dysfunction, excitotoxicity, neuroapoptosis, disruption of cytoskeletal assembly, and dysregulation of brain-derived neurotrophic factor (BNDF). Additionally, they can generate epigenetic changes that can be transmitted intergenerationally. These effects are related to age, dose, number of anesthetics received, and duration of exposure to said drugs and can be reversible or permanent, caused by direct or indirect perturbations on neurons. These disturbances may manifest as neurodevelopmental disorders later in life. This work aimed to review the cellular mechanisms involved in these alterations.

A neurophysiological basis for aperiodic EEG and the background spectral trend

Electroencephalograms (EEGs) display a mixture of rhythmic and broadband fluctuations, the latter manifesting as an apparent 1/f spectral trend. While network oscillations are known to generate rhythmic EEG, the neural basis of broadband EEG remains unexplained. Here, we use biophysical modelling to show that aperiodic neural activity can generate detectable scalp potentials and shape broadband EEG features, but that these aperiodic signals do not significantly perturb brain rhythm quantification. Further model analysis demonstrated that rhythmic EEG signals are profoundly corrupted by shifts in synapse properties. To examine this scenario, we recorded EEGs of human subjects being administered propofol, a general anesthetic and GABA receptor agonist. Drug administration caused broadband EEG changes that quantitatively matched propofol’s known effects on GABA receptors. We used our model to correct for these confounding broadband changes, which revealed that delta power, uniquely, increased within seconds of individuals losing consciousness. Altogether, this work details how EEG signals are shaped by neurophysiological factors other than brain rhythms and elucidates how these signals can undermine traditional EEG interpretation.

Dispensing a non-verbal child on the autistic spectrum

Former hospital dispensing optician Stephen Golding shares one of his more challenging and rewarding cases, a child that could only be refracted and dispensed under general anaesthetic

Time to Wake Up! The Ongoing Search for General Anesthetic Reversal Agents.

How general anesthetics work remains a topic of ongoing study. A parallel field of research has sought to identify methods to reverse general anesthesia. Reversal agents could shorten patients' recovery time and potentially reduce the risk of postoperative complications. An incomplete understanding of the mechanisms of general anesthesia has hampered the pursuit for reversal agents. Nevertheless, the search for reversal agents has furthered understanding of the mechanisms underlying general anesthesia. The study of potential reversal agents has highlighted the importance of rigorous criteria to assess recovery from general anesthesia in animal models, and has helped identify key arousal systems (e.g., cholinergic, dopaminergic, and orexinergic systems) relevant to emergence from general anesthesia. Furthermore, the effects of reversal agents have been found to be inconsistent across different general anesthetics, revealing differences in mechanisms among these drugs. The presynapse and glia probably also contribute to general anesthesia recovery alongside postsynaptic receptors. The next stage in the search for reversal agents will have to consider alternate mechanisms encompassing the tripartite synapse.

General anaesthetics reduce acute lymphoblastic leukaemia malignancies in vitro and in vivovia CXCR4 and osteopontin mediated mechanisms.

Acute lymphoblastic leukaemia (ALL) is a common type of cancer in children. General anaesthetics are often used on patients undergoing painful procedures during ALL treatments but their effects on ALL malignancy remain unknown. Herein, we aim to study the effect of propofol and sevoflurane on the migration, homing and chemoresistance of ALL cells. NALM-6 and Reh cells were treated with propofol (5 and 10 μg/ml) or sevoflurane (3.6%) in vitro for six hours. Then, cells were harvested for adhesion assay and migration assay in vitro. In in vivo experiments, GFP-NALM-6 cells were pre-treated with propofol (10 μg/ml) or sevoflurane (3.6%) for six hours. Then, cells were injected intravenously to C57BL/6 female mice followed by intravital microscopy. For chemoresistance study, cells were treated with rising concentrations of Ara-c (0.05-50 nM) plus 10μg/ml of propofol or Ara-C plus 3.6% of sevoflurane for 4 hours, followed by the assessment of cell viability via CCK-8 assay and detection of autophagy via flow cytometry. Both anaesthetics reduced in vivo migration and in vivo homing as exemplified by 1) the reduction in the number of cells entering the bone marrow and 2) the disturbance in homing location in relation to endosteal surface. Our results indicated that general anaesthetics reduced the surface CXCR4 expression and the adhesion of leukaemia cells to thrombin cleaved osteopontin (OPN) was reduced. Those changes might result in the alterations in migration and homing. In addition, both anaesthetics sensitised ALL cells to Ara-c possibly through CXCR4 mediated mechanisms. Propofol but not sevoflurane enhanced chemo-related cell death via inducing cytotoxic autophagy. Together, our data suggest that both propofol and sevoflurane could reduce ALL migration, and homing in vivo and in vitro via CXCR4 and OPN mediated mechanisms. Both anaesthetics could sensitise ALL cells to chemotherapy possibly via CXCR4 mediated mechanisms.

(167) Penile Plication is Well Tolerated Under Conscious Sedation: A Prospective Comparison of Deep Intravenous Vs. Nursing Administered Conscious Sedation

Abstract Introduction Penile plication is a common and effective surgical treatment for Peyronie's Disease. Although generally performed under general or spinal anesthesia, patient tolerability of penile plication under conscious sedation (CS) has several advantages: reduced anesthetic risk, health care cost savings, decrease wait times, and the ability conduct in outpatient facilities. While CS would provide significant potential benefit, there have been no evaluations of patient-reported tolerability to penile plication completed under conscious sedation nor comparisons with varying administrations. Objective To evaluate and compare patient-reported tolerability of penile plication performed under two CS sedation approaches: (1) deep intravenous conscious sedation (IVCS) administered by anesthesiologists and (2) nursing administered conscious sedation (NACS). Methods We evaluated procedure tolerability in a prospective cohort of 40 adult patients (23 IVCS; 17 NACS) undergoing primary penile plication between August 2022 and May 2023. Revision surgeries, and those with hourglass or hinge deformities were excluded. IVCS patients were administered midazolam (5mg) and ketamine (20mg) along with a continuous infusion of propofol (25-50 mcg/kg/min) and remifentanil (0.05 mcg/kg/min). NACS sedation protocol consisted of midazolam (1-2 mg) and fentanyl (50-100 ug). Patient baseline characteristics, procedure information, pain assessments (Likert scale; 0 [no pain]-10[most pain]) made by the patient and surgeon before during and after the procedure were collected. Following a post-surgical healing period, patients were contacted and administered an evaluated standardized patient tolerability questionnaire. Overall patient tolerability, pain assessments, and complication rates were compared descriptively, and using Wilcoxon sign-rank tests and McNemar tests. Results Baseline characteristics were similar between IVSC and NACS groups. Median pre-operative curvature of the IVCS cohort was 55 degrees (IQR=43.75-76.25) whereas the NACS curvature was 45 degrees (IQR=45-60). There was a 100% procedural success rate with no intra-operative concerns leading to the abortion of the procedure or conversion to general anesthetic. At six-week post-operative follow up, all patients had functional curvature. 100% of patients in the IVCS and NACS cohorts reported that they would recommend CS to others. Additionally, 95% (19/20; CI95=75.3%-99.0%) of those undergoing IVCS and 93.3% (14/15; CI95=70.2-98.8%) of the NACS cohort would choose CS over general anesthetic if they had to undergo the same surgery again. Sedation choice did not differ between CS groups (p=1.0). Most patients reported no pain pre-operatively (IVCS:[18/20]; NACS:[13/15]; p=1.0), peri-operatively (IVCS:[16/20]; NACS:[13/15]; p=0.68), or immediately post-operatively (IVCS:[14/20]; NACS:[14/15]; p=0.20). Two-hour post-operative pain did not differ between groups (p=0.89). Median two-hour post-operative IVCS pain was 2.5 (IQR=0-5.0) whereas median NACS pain was 3.0 (IQR=1.5-3.0). Conclusions Penile plication is exceptionally well tolerated when completed under either anesthesiologist administered intravenous conscious sedation or nursing administered conscious sedation. Most patients would choose conscious sedation over general anesthetic for the procedure in the future and all would recommend conscious sedation to others. Self-reported pain did not differ between groups and most patients reported no pain pre-, peri-, or immediately post-operatively. These results suggest that penile plication surgery can be completed in an outpatient setting under conscious sedation administered by trained nursing staff, which is expected to decrease costs, risks and wait-times of the procedure. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Boston Scientific.

(040) Local Anesthesia Only for Penile and Scrotal Procedures: A Prospective Analysis of Patient Tolerability as an Alternative to Sedation

Abstract Introduction Traditionally, urological procedures utilize general or spinal anesthesia (GA) in an operating room (OR) to achieve adequate periprocedural pain relief. However, this approach presents various obstacles, including high OR related expenses, difficulties in accessing healthcare in rural areas, higher risk of anesthetic related complications and long wait times for patients due to limited OR space. This is particularly evident in penile and scrotal procedures, which often receive non-urgent treatment and result in wait times exceeding six months in Canada. The use of local anesthesia (LA) only is an appealing approach that has been gaining more traction in recent literature – however, no study to date has evaluated patient-reported tolerability to procedures conducted in this manner. Objective To investigate the surgical outcomes and patient-reported tolerability of penile and scrotal urologic procedures performed solely under LA. Additionally, information regarding complications is collected to provide data regarding the safety of this method, offering a viable alternative without the need for sedation. Methods This prospective study is registered as a clinical trial NCT05617261. Adult patients undergoing penile or scrotal surgery under LA only have been enrolled since August 2022, and is ongoing until August 2023. Procedures of interest include hydrocelectomies, spermatocelectomies, epididymectomies, testicular biopsies, circumcisions and frenulectomies. For scrotal procedures LA is administered along the median raphe along with a spermatic cord block, and for penile procedures a subcutaneous ring and dorsal penile block is utilized. Demographics, surgeon- and patient-reported visual analogue pain scores (VAS), and surgical variables are collected. Patient tolerability to the procedure and future anesthetic choice for a hypothetical repeat procedure are assessed at a follow-up appointment as our primary outcome. Complication data is also collected including recurrence (if applicable), emergency room visits, excess pain, hematoma & infection. Statistical tests include analyses to determine associations between demographic or surgical variables and patient-reported outcomes. Results Thus far, 215 patients are enrolled with complete follow-up data and statistical analysis on 72 patients. The mean age ± SD is 42.2 ± 16.4 years and there has been a 100% success rate with no perioperative complications or conversions to sedation or general anesthetic. Table 1 highlights the current patient demographic differences between those who do or do not recommend LA. Table 2 describes VAS at each point in time. On follow-up, 93.1% of patients indicated they would opt for LA for a hypothetical repeat procedure, with Figure 1 illustrating this by procedure type. Of the minority opting for GA, only 2 patients did so due to excess pain – highlighting that patient tolerability is not a limiting factor; instead, a desire to have no memory of the procedure is prevalent in this small cohort. Conclusions LA only is a promising technique for various scrotal and penile urologic procedures with high levels of patient tolerability. As we continue our analysis, we anticipate minimal complication rates similar to existing literature and data highlighting cost savings to our public health care system with a substantial reduction in patient wait times and surgical and recovery times – allowing for increased surgical efficiency and accessibility. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Boston Scientific.

Factors associated with unintended perianesthesia hypothermia

Background Our hypothesis was that total intravenous anesthesia (TIVA) is associated with an increase in hypothermia. Methods Inclusion criteria were patients from the National Anesthesia Clinical Outcomes Registry undergoing a general anesthetic during 2019. Data collected included patient age, sex, American Society of Anesthesiologists physical status classification system score (ASAPS), duration of anesthetic, use of TIVA, type of procedure, and hypothermia. Continuous variables were compared using Student’s t test or Mann Whitney rank sum as appropriate. Mixed effects multiple logistic regression was performed to determine the association between independent variables and hypothermia. Results There was a low incidence of hypothermia (1.2%). Patients who became hypothermic were older, had a higher median ASAPS, and had a higher rate of TIVA. TIVA patients had a significantly increased odds for hypothermia when controlling for covariates. Patients undergoing obstetrical, thoracic, or radiological procedures had increased odds for hypothermia. In a matched cohort subset, TIVA was associated with a greater rate and increased odds for hypothermia. Conclusions The novel and noteworthy finding was the association between TIVA and perianesthesia hypothermia. Thoracic, radiologic, and obstetrical procedures were associated with greater rates of and odds for hypothermia. Other identified factors can help to stratify patients for risk for hypothermia.

Effect of general and spinal anaesthesia on post-operative wound healing during laparoscopic totally extraperitoneal inguinal hernia repair: A meta-analysis.

Totally extraperitoneal prosthetic (TEP) is a surgical technique for the treatment of hernia. The purpose of this research is to compare the efficacy of both general anaesthesia and spine anaesthesia for TEP herniorrhaphy. The number of patients who received TEP operations related to the injury from 2008 to 2022 was counted in this study. Patients with TEP operation were classified into general anaesthesia and spine anaesthesia. In this research, 186 related articles were found in the data base, and in the end, 8 were analysed. This study involved 2452 cases of hernia. The data of the operation time, the infection of the wound and the bleeding of the wound were analysed. The analysis of the data was done with RevMan 5.3. Results indicated that there was no significant difference between general anaesthesia and spinal anaesthesia in post-surgical rates for post-operative wound infection (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.49-1.83; p = 0.86); In general anaesthesia, there was no difference in the risk of post-operative wound haematoma when compared with those treated with spinal anaesthesia (OR, 2.96; 95% CI, 0.37-23.69; p = 0.31). In the seven trials, there was no difference in the duration of the surgery between the general anaesthetic and the spinal anaesthesia group (mean difference, -1.44; 95% CI, -4.11 to 1.22; p = 0.29). Data from the available meta-analysis indicate that there is no difference in the risk of post-operative wound infection or wound haematoma when treated with TEP.

Demonstrating the safety profile of ketamine as procedural conscious sedation in infants; a prospective cohort study of 904 cases

Background: Conscious sedation has both a sedative and an analgesic effect. Ketamine is an increasingly popular choice for procedural conscious sedation in a paediatric day surgery. Ketamine is also cheaper than general anaesthetic. The objective of our study is to investigate the number of adverse events when using ketamine for procedural conscious sedation and demonstrate its safety profile for use in paediatric day surgery in a community setting in infants. Methods: A single-centre, single surgeon, single procedure 5-year longitudinal prospective review of 904 infants undergoing elective day-care surgery using ketamine for procedural conscious sedation between 2016 and 2020. Patients were stratified for pre-anaesthetic co-morbidities based on the American Society of Anesthesiologists (ASA) classification system. Results: All patients were between 4 weeks and 1 year and 98.7% were ASA Class 1. Most children received ketamine intramuscularly and only one child required additional ketamine to maintain procedural conscious sedation. There were no serious adverse events and there were 27 mild adverse events in 26 patients (2.88% patients). The most common adverse event was hypersalivation, which occurred in 11 infants. Conclusions: Ketamine is a safe drug for procedural conscious sedation and should be considered more for infants undergoing elective day-care surgery provided that all staff conducting procedures have advanced training in paediatric and neonatal airway management and resuscitation.