Search Results (77)

Background: With renewed interest in long-duration space missions, there is growing exploration into synthetic torpor as a countermeasure to mitigate physiological stressors. Sedative agents, particularly those used in clinical anesthesia, have been proposed to replicate aspects of natural torpor, including reduced metabolic rate, core temperature, and brain activity. Objectives: This systematic review aims to evaluate the potential of sedative agents to induce torpor-like states suitable for extended spaceflight. The review specifically investigates their pharmacokinetics, pharmacodynamics, and performance under space-related stressors such as microgravity and ionizing radiation. Methods: We conducted a comprehensive search across multiple databases (e.g., PubMed, Scopus, Web of Science) for studies published from 1952 to 2024. Eligible studies included experimental, preclinical, and clinical investigations examining sedative agents (especially inhalation anesthetics) in the context of metabolic suppression or space-relevant conditions. Screening, selection, and data extraction followed PRISMA guidelines. Results: Out of the screened records, 141 studies met the inclusion criteria. These were thematically grouped into seven categories, including torpor physiology, anesthetic uptake, metabolism, and inhalation anesthetics. Sedative agents showed variable success in inducing torpor-like states, with inhalation anesthetics demonstrating promising metabolic effects. However, concerns remain regarding delivery methods, safety, rewarming, and the unknown effects of prolonged use in space environments. Conclusions: Sedative agents, particularly volatile anesthetics, hold potential as tools for inducing synthetic torpor in space. Nevertheless, significant knowledge gaps and technical challenges persist. Further targeted research is required to optimize these agents for safe, controlled use in spaceflight settings. Full article

Background and Objectives: Metabolic-flow (<0.35 L/min) anesthesia is practiced more often as manufacturers provide newer technologies, yet the benefits of metabolic-flow anesthesia have not been fully investigated. This study aimed to investigate the feasibility and safety of automated gas control (AGC^®) mode, which provides metabolic-flow anesthesia, in a pediatric population. Materials and Methods: Pediatric surgery patients between 1 and 10 years of age were included in this prospective observational trial. After intravenous induction and safe orotracheal intubation, AGC^® was initiated, and total sevoflurane consumption (mL) and wash-in speed-based sevoflurane consumption data were collected to measure feasibility. For safety, inspired (F_iO₂), alveolar (F_AO₂), and expired (F_EO₂) oxygen concentration data, and inspired and alveolar sevoflurane (F_iSevo and F_ASevo, respectively) concentration data, were recorded. Changes in fresh gas flow (FGF) throughout the procedure and postoperative recovery data were also compared. Results: A total of 130 patients were eligible for this study, and 121 patients were included in the analyses; 30 patients had a wash-in speed of 4 (WI4) and 91 patients had a wash-in speed of 8 (WI8) at follow-up. The total mean sevoflurane consumption was 9.35 ± 4.93 mL for a median surgery duration of 100 min. WI8 patients consumed more sevoflurane (9.92 ± 5.08 mL vs. 7.79 ± 4.19 mL, p = 0.04). At the 15th and 30th minutes, the FGF dropped under minimal flow and metabolic flow limits, respectively (p < 0.001). The times to extubation and obeying commands were shorter in WI8 patients (8 (5–10) vs. 11 (5–15) p = 0.03, and 9.5 (5–10.5) vs. 13 (9–17) p < 0.01). Conclusions: Maintenance with AGC^® may offer up to 40 h of anesthesia, considering that the volume of a sevoflurane bottle is 250 mL, reflecting exceptional savings compared to conventional anesthesia management. Metabolic flow anesthesia driven by AGC^® is feasible and safe in pediatric anesthesia practice. Full article

Anesthetic management of the pregnant patient undergoing non-obstetric surgery requires careful consideration of both maternal and fetal well-being. Key factors include appropriate drug selection to minimize fetal exposure, maintenance of uteroplacental perfusion, and management of physiological changes associated with pregnancy, such as altered respiratory function and increased blood volume. Regional anesthesia is often preferred to reduce the risks of general anesthesia, although considerations such as positioning, airway management, and monitoring are crucial. Multidisciplinary collaboration is essential to optimize outcomes, ensuring that both maternal health and fetal safety are prioritized throughout the perioperative period. Full article

This prospective, non-blinded study assessed the performance of a portable anesthesia machine with an oxygen concentrator (PAM_OC) across various oxygen flow rates and vaporizer settings, incorporating both in vitro and in vivo experiments. The oxygen delivery test measured the time required to reach 90% fraction of inspired oxygen (FIO₂) at various flow rates. The vaporizer test assessed the time to stabilize maximum fraction of inspired isoflurane (FIIso) concentration at various oxygen flow rate and vaporizer settings. In the in vivo test, six adult male Beagle dogs (11.4 ± 1.4 kg) were evaluated. The in vivo evaluation included monitoring physiological parameters during isoflurane anesthesia. The higher flow rates significantly reduced the time to plateau for FIO₂ (p < 0.001). Maximum FIIso values were lower than the vaporizer dial settings, and increased oxygen flow rates significantly reduced the time required to reach target values (p < 0.001). Physiological parameters remained stable throughout anesthesia, confirming adequate oxygenation and anesthetic maintenance. The PAMoc, despite its lower pounds per square inch, yielded predictable outcomes consistent with those obtained in conventional anesthesia systems. These results demonstrated the viability of the PAMoc for anesthesia administration in the field and other challenging environments. Full article

The occurrence of triplication in the deciduous teeth is rare. However, it can cause several problems in primary dentition, alteration of development, and eruption of permanent successors. Case Presentation: A three-year-old boy presented with an exuberant acute periapical abscess in the left front teeth region of the upper jaw. Examination revealed a presence of a triple tooth involving the central and lateral left primary incisors and a supernumerary tooth. Radiographs showed that the fused teeth had separate roots, pulp chambers and root canals. The implemented treatment was extraction under local anesthesia. After 2 years of observation, surgical exposure of the crowns of the permanent maxillary central incisor was performed. After seven years, the permanent dentition was completed without any sequelae. Discussion: Triple tooth, as observed in this case report, results from the union of three tooth germs, potentially influenced by physical, hereditary, or environmental factors, leading to esthetic and functional issues and increased susceptibility to caries. Treatment is challenging, requiring preventive care, complex endodontic procedures, and, in some cases, extraction with space maintenance to avoid future orthodontic complications. Conclusion: Early diagnosis, an adequate treatment plan and clinical monitoring should be performed, aiming at preventing the possible disturbances. Full article

Background and Objectives: Remifentanil is a member of the fentanyl family and a short-acting, esterase-metabolized opioid that offers potential advantages over fentanyl in ophthalmic surgeries characterized by rapid patient turnover. This study aimed to compare two different analgesia induction regimes, remifentanil or fentanyl, with respect to intraoperative hypotensive events and perioperative process times in patients undergoing ophthalmic surgery under general anesthesia. Materials and Methods: Clinical data of 500 patients either receiving remifentanil infusion (R group, 0.4–0.5 μg/kg/min at induction, and then 0.1 µg/kg/min maintenance dose) or fentanyl bolus (F group, 1 μg/kg for induction followed by 0.1 μg/kg/min remifentanil maintenance dose) were analyzed in this retrospective study. All patients received a propofol injection as part of the induction and sevoflurane for the maintenance of anesthesia. We investigated hemodynamic events as defined by the administration of vasopressors, atropine and Akrinor (Theodrenaline and Cafedrine), as well as procedural times in the two groups. Results: There was no difference in hypotensive events between the two groups. However, there was a relationship between preoperative ASA (American Society of Anesthesiologists) status and vasopressor administration. The amount of propofol for the induction of anesthesia exhibited a significant correlation to the age of the patients (p < 0.05). The time from the end of anesthesia to discharge from the recovery room was significantly reduced by approximately 6 min per patient in the remifentanil group (p < 0.01). In conclusion, the induction of anesthesia with high-dose remifentanil combined with propofol can significantly shorten the time span to discharge from the recovery ward compared to fentanyl bolus administration, without an increase in the administration of vasopressors in patients undergoing ophthalmic surgery in general anesthesia. Conclusions: These findings suggest that remifentanil may be a more effective choice for anesthesia management in settings with high patient turnover. Full article

Background: Midazolam is widely used in clinical anesthesia, but its effects on the Bispectral Index (BIS) and propofol concentration at the effector site (CeP) are underexplored. This study investigates the pharmacodynamic interaction between midazolam and propofol in total intravenous anesthesia (TIVA) with target-controlled infusion (TCI), focusing on Schnider and Eleveld models. Methods: This prospective study included breast surgery patients receiving TIVA-TCI. BIS and CeP were assessed at loss of responsiveness (LoR), during maintenance (MA), and at return of responsiveness (RoR). Incidences of unwanted spontaneous responsiveness (USRE), burst suppression episodes (BSuppE), and postoperative delirium (POD) were recorded. Results: Midazolam premedication significantly reduced propofol doses and CeP at LoR and during MA, without affecting CeP at RoR. In the Schnider model, midazolam reduced total propofol dose, while in the Eleveld model, it lowered BIS at LoR. Unwanted anesthesia events occurred in 36.2% of patients, including USRE (10%), BSuppE (26.2%), and POD (1.2%). BSuppE rates were lower in the Schnider model and reduced in the midazolam group in the Eleveld model. Conclusions: Midazolam premedication influences CeP and BIS in TIVA-TCI, with model-specific variations, optimizing propofol management and improving patient outcomes. Full article

Background and Objectives: The aim of our study is to determine the effects of analgesia nociception index (ANI) monitoring on intraoperative opioid consumption, postoperative analgesia, and the recovery unit length of stay in patients with a preoperative femoral nerve block (FNB) undergoing total knee arthroplasty (TKA) surgery under general anesthesia. Materials and Methods: Seventy-four patients in the American Society of Anesthesiologists Physical Status (ASA-PS) I-III scheduled for TKA under general anesthesia were included in this study. After FNB, the patients were divided into two groups (control group (n = 35)–ANI group (n = 35)). After standard anesthesia induction in both groups, maintenance was conducted using sevoflurane and remifentanil infusion with a bispectral index (BIS) between 40 and 60. In the control group, the intraoperative remifentanil infusion dose was adjusted using conventional methods, and in the ANI group, the dose was adjusted using ANI values of 50–70. The duration of operation, duration of surgery, extubation time, tourniquet duration and pressure, and the amount of remifentanil consumed intraoperatively were recorded. Results: Intraoperative remifentanil consumption was lower in the ANI group compared to the control group (p = 0.001). The time to reach a Modified Aldrete Scale score (MAS) ≥ 9 was shorter in the ANI group (p < 0.001). NRS scores in the recovery unit and 4, 8, 12, and 24 h postoperatively were lower in the ANI group compared to the control group (p = 0.006, p < 0.05). There was a weak significant inverse relationship between the last ANI values measured before extubation and NRS scores in the postoperative recovery unit (r: −0.070–0.079, p: 0.698–0.661). No difference was observed between the groups in other data. Conclusions: In patients undergoing TKA with FNB under general anesthesia, ANI monitoring decreased the amount of opioids consumed intraoperatively and postoperative pain scores and shortened the length of stay in the recovery unit. We suggest that ANI monitoring in intraoperative analgesia management may be helpful in determining the dose of opioid needed by the patient and individualized analgesia management. Full article

Formosan serows are an endemic species in Taiwan. Alfaxalone, a γ-aminobutyric acid_A agonist, induces or maintains anesthesia in various veterinary species with reported potential adverse effects of respiratory depression and tachycardia. α2-Adrenoceptor agonists exert sedative and muscle relaxation effects, along with substantial cardiovascular adverse effects. Here, we aimed to evaluate the anesthetic effects of alfaxalone combined with xylazine or dexmedetomidine (AX vs. AD, respectively) in Formosan serows. In this randomized, masked study, AX was administered to four serows, and AD was administered to five serows intramuscularly via blow dart. The time and score of induction and recovery were recorded. Post-intubation, isoflurane was administered for maintenance anesthesia. Heart rate (HR), respiratory rate (RR), peripheral saturation of oxygenation (SpO₂), rectal temperature (RT), and end-tidal CO₂ (EtCO₂) were recorded every five to eight minutes. Atipamezole and tolazoline were administered to antagonize dexmedetomidine and xylazine post-procedure, respectively. Both combinations allowed smooth induction and recovery. The AD group exhibited significantly lower HR and SpO₂ and significantly higher RT and EtCO₂ than the AX group (both p < 0.01). The AD-treated serows exhibited notable muscle rigidity after induction and significant hypoventilation and hypoxemia during the procedure. Although alfaxalone combined with dexmedetomidine or xylazine can produce satisfactory induction and recovery in Formosa serows, notable hypoxemia and hypoventilation are induced by the alfaxalone–dexmedetomidine combination compared to the alfaxalone–xylazine combination. Full article

Background: A PBPK model allows the prediction of the concentration of drug amounts in different tissues and organs over time and can be used to simulate and optimize different therapeutic protocols in healthy and sick individuals. The objective of this work was to create a PBPK model to predict propofol doses for healthy canines and canines with hepatic impairment. Methods: The study methodology was divided into two major phases, in which the first phase consisted of creating the PBPK model for healthy canines, and in the second phase, this model was adjusted for canines with hepatic impairment. The model for healthy canines presented good predictive performance, evidenced by the value of the performance measure of the geometric mean fold error that ranged from 0.8 to 1.25, meeting the double error criterion. The simulated regimen for healthy canines, i.e., of 5 mg/kg (administered as a bolus) followed by a continuous infusion at a rate of 0.13 mg/kg/min, was sufficient and ensured that all simulated subjects achieved the target plasma concentration. Canines with 60% and 40% liver function had infusion rate adjustments to ensure that individuals did not exceed the therapeutic window for maintenance of anesthesia. Results: The results presented in this manuscript are suggestive of the effectiveness and practicality of a PBPK model for propofol in canines, with a particular focus on hepatic impairment. Full article

Background/Objectives: Postoperative delirium is a frequent complication in children undergoing general anesthesia. It has been suggested that inflammation and oxidative stress contribute to the pathophysiology of delirium. The aim of our study was to investigate the relationship between inflammatory markers and delirium. Methods: A total of 221 children in the ASA 1–3 risk group who underwent adenoidectomy, tonsillectomy, and/or ventilation tube application were included in our single-center, prospective, and observational study approved by the Ethics Committee, numbered E1-23-3197. Patients whose parental consent was obtained were either premedicated with oral midazolam preoperatively or taken to surgery without premedication, depending on the anesthesiologist’s preference. After induction with sevoflurane, rocuronium and fentanyl were administered intravenously. Sevoflurane and infusion of remifentanil were administered for maintenance. At the end of the operation, patients were transferred to the recovery unit and followed up for 30 min. They were evaluated with the Face, Legs, Activity, Cry, and Consolability (FLACC) Scale and Pediatric Anesthesia Emergence Delirium (PAED) Scale. Results: Delirium was observed in 80 patients. There was no significant difference between patients with and without delirium in terms of neutrophil/lymphocyte ratio, mean platelet volume, or platelet distribution volume. Lymphocyte count, PAED score, and FLACC score were statistically higher in patients with delirium (W = 4407.5, p-value = 0.006997; W = 0, p-value < 2.2 × 10⁻¹⁶; W = 9489, p-value < 2.2 × 10⁻¹⁶, respectively). Conclusions: No statistically significant relationship was found between hematologic inflammatory markers and delirium. Controlled studies with larger sample sizes are needed to determine whether these markers have strong predictive value. Full article

Objectives: Laparoscopic gynecological surgeries are commonly performed under general anesthesia and can induce cardiovascular depression and hypotension, requiring vasopressor support. Remimazolam, a novel ultra-short-acting benzodiazepine, is used to treat minimal cardiovascular depression. This study compared the hemodynamic effects of remimazolam and sevoflurane anesthesia in patients undergoing laparoscopic gynecological surgery. Methods: A retrospective analysis was conducted on 474 patients who underwent laparoscopic gynecological surgery at Korea University Anam Hospital between September 2021 and December 2022. The patients were categorized into two groups based on the anesthetic agent used: remimazolam or sevoflurane. Hemodynamic parameters, vasopressor use, and intraoperative variables were compared between anesthetic agents. Propensity score matching was applied to account for potential confounders, and logistic regression was utilized to assess the relationship between anesthesia type and outcomes. Results: Remimazolam anesthesia was linked to a significantly lower incidence of vasopressor use compared to sevoflurane-based anesthesia (3.7% vs. 19.5%, p < 0.0001). The odds of requiring vasopressor support were significantly lower during the post-induction and maintenance phases in the remimazolam group. Furthermore, hemodynamic stability, particularly systolic and mean arterial pressures, was better maintained with remimazolam than sevoflurane. Conclusions: Remimazolam provides superior hemodynamic stability and reduces the need for vasopressor support during laparoscopic gynecological surgery compared with sevoflurane. Full article

Within biomedical engineering, there has been significant collaboration among clinicians, control engineers, and researchers to tailor treatments to individual patients. Anesthesia is integral to numerous medical procedures, necessitating precise management of hypnosis, analgesia, neuromuscular blockade, and hemodynamic variables. Recent attention has focused on computer-controlled anesthesia and hemodynamic stabilization. This research proposes the integration of a decentralized control strategy for the induction phase with a decoupled control approach for the maintenance phase, aimed at mitigating interactions within the multivariable human system. The proposed strategy is based on fractional-order controllers. The solution is validated using an open-source patient simulator featuring data from 24 virtual patients, demonstrating the efficiency of the proposed approach with respect to decentralized control. Full article

Background/Objectives: Anesthesia plays a very important role in the successful management of intraoperative neuromonitoring (IONM). The aim of our study was to investigate the impact of anesthesia induction and maintenance on the quality of signals during surgeries on the thyroid and parathyroid glands using neuromonitoring. Methods: The study included 72 patients who underwent surgery with IONM for one year. All the patients were intubated using a Glidescope videolaryngoscope with a hyperangulated blade. Two different approaches were used to facilitate intubation: succinylcholine-1 mg/kg and rocuronium bromide-0.3 mg/kg. For anesthesia maintenance, total intravenous anesthesia (TIVA) or combined anesthesia was used. Patients’ body movements during operations, as well as electromyography signals from the vagus and recurrent laryngeal nerves before resection, were recorded as V1 and R1. Results: Intraoperative unwanted movements were recorded in 25% of patients. Undesired movements were more frequently recorded in the TIVA group compared to the combined anesthesia group (p < 0.001) as well as in patients who received succinylcholine compared to patients who received rocuronium bromide (p = 0.028). Type of anesthesia maintenance as well as type of muscle relaxant did not affect the quality of recorded nerve signals. (p = 0.169 and p = 0.894, respectively). Conclusions: The type of muscle relaxant used significantly affects the occurrence of undesirable movements during thyroid surgery with IONM, while the type of anesthesia maintenance did not influence either the quality of the obtained signal or the occurrence of undesirable movements. Full article

Background/Objectives: Previous preclinical studies have shown that desflurane might have the most significant cardioprotective effect of all volatile anesthetics. However, data regarding the cardioprotective effects of desflurane versus sevoflurane are lacking. Therefore, we evaluated the effect of the maintenance of anesthesia using desflurane versus sevoflurane on the postoperative maximum concentrations of cardiac biomarkers in older adults undergoing low- to moderate-risk noncardiac surgery. Methods: In this secondary analysis of a prospective randomized trial, we included all 190 older adults undergoing low- to moderate-risk noncardiac surgery. Patients were randomized to receive desflurane or sevoflurane for the maintenance of anesthesia. We administered desflurane or sevoflurane, aiming at a BIS value of 50 ± 5. The cardiac-specific biomarkers included troponin T, NT-proBNP, and copeptin, which were measured preoperatively, within one hour after surgery, and on the second postoperative day. Results: There were no significant differences between the desflurane and sevoflurane groups in the postoperative maximum concentrations of troponin T (11 ng.L⁻¹ [8; 16] versus 13 ng.L⁻¹ [9; 18]; p = 0.595), NT-proBNP (196 pg.mL⁻¹ [90; 686] versus 253 pg.mL⁻¹ [134; 499]; p = 0.288), or copeptin (19 pmol.L⁻¹ [7; 58] versus 12 pmol.L⁻¹ [6; 41]; p = 0.096). We also observed no significant differences in the troponin T, NT-proBNP, or copeptin concentrations between the desflurane and sevoflurane groups at any measured timepoint (all p > 0.05). Conclusions: In contrast to preclinical studies, we did not observe a significant difference in the postoperative maximum concentrations of cardiac biomarkers. It seems likely that desflurane does not exert significant clinical meaningful cardioprotective effects in older adults. Thus, our results do not support the use of desflurane in patients undergoing low- to moderate-risk noncardiac surgery. Full article