Intravenous Anaesthesia Regimen Research Articles

Roadmap for Motor Evoked Potential (MEP) Monitoring for Patients Undergoing Lumbar and Lumbosacral Spinal Fusion Procedures

ABSTRACT MEPs are recommended for patients undergoing lumbar and lumbosacral procedures in which intraoperative neuromonitoring (IONM) is being utilized. While electromyography (EMG) provides critical nerve root proximity information, spontaneous EMG discharges are relatively poor at reliably diagnosing spinal nerve root dysfunction. In contrast, research indicates that MEPs are both sensitive and specific in diagnosing evolving spinal nerve root dysfunction. There is conflicting evidence, however, and it must be emphasized that the value of adding MEPs is only realized when practices and techniques are optimized. The ideal anesthetic plan is an optimized total intravenous anesthetic (TIVA) regimen. Selection of appropriate anesthetics and dosing is important for optimizing baseline response amplitudes and promoting diagnostic confidence in analyzing signal changes. An adaptive set of alert criteria that account for baseline amplitude and morphology fluctuations should guide the determination of significant signal change. The therapeutic impact of accurate diagnostic information depends on the timeliness of diagnosis and intervention. Prior to the start of surgery, a plan to obtain MEPs at least once every 10 minutes during the active part of the procedure and after every significant surgical maneuver should be agreed upon, and the intervention plan should include but not be limited to possible removal of hardware and release of retraction or distractive forces. In summary, MEPs can improve monitoring of at-risk nerve root function, but the accuracy and therapeutic impact of such monitoring depend on perioperative planning and communication that optimize use of this modality.

Depth of anesthesia by Narcotrend® and postoperative characteristics in children undergoing cardiac surgery under extracorporeal circulation: a retrospective comparison of two anesthetic regimens.

Depth of anesthesia may be insufficient in pediatric cardiac anesthesia if a total intravenous anesthetic regimen with opioids and midazolam is used during cardiopulmonary bypass. The advantages of sevoflurane-based balanced anesthesia may be (1) a more graduated regulation of the depth of anesthesia during cardiopulmonary bypass and (2) a reduction in postoperative ventilation time for children in comparison with total intravenous anesthesia. To evaluate a possibly positive effect of sevoflurane-based balanced anesthesia in children undergoing cardiac surgery we analyzed whether this anesthetic regimen had a significant effect related to (1) depth of anesthesia, (2) the need for opioids during cardiopulmonary bypass as well as on postoperative characteristics such as (3) time of postoperative ventilation, and (4) duration of stay in the intensive care unit in comparison with total intravenous anesthesia. In a retrospective analysis, data from heart-lung machine protocols from 2013 to 2016 were compared according to anesthetic regimen (sevoflurane-balanced anesthesia, n = 70 vs. total intravenous anesthesia, n = 65). Children (age: 8 weeks to 14 years) undergoing cardiac surgery with cardiopulmonary bypass were included. As a primary outcome measure, we compared Narcotrend® system-extracted data to detect insufficient phases of anesthetic depth during extracorporeal circulation under moderate hypothermia. Postoperatively, we measured the postoperative ventilation time and the number of days in the intensive care unit. Furthermore, we analyzed patients' specific characteristics such as opioid consumption during cardiopulmonary bypass. Regression analysis relating primary objectives was done using the following variables: anesthetic regimen, age, severity of illness/surgery, and cumulative dosage of opiates during cardiopulmonary bypass. No significant differences were observed in descriptive patient characteristics (age, body weight, height, and body temperature) between the two groups. Further, no significant differences were found in depth of anesthesia by analyzing phases of superficial B1-C2-electroencephalography Narcotrend® data. No marked difference between the groups was observed for the duration of postoperative intensive care unit stay. However, the postoperative ventilation time (median (95% CI, hours)) was significantly lower in the sevoflurane-based balanced anesthesia group (6.0 (2.0-15.0)) than in the total intravenous anesthesia group (13.5 (7.0-25)). A higher dosage of opioids and midazolam was required in the total intravenous anesthesia group to maintain adequate anesthesia during cardiopulmonary bypass. Regression analysis showed an additional, significant impact of the following factors: severity of illness and severity grade of cardiac surgery (according to Aristotle) on the primary endpoint. In children undergoing cardiac surgery in our department, the use of sevoflurane-balanced anesthesia during cardiopulmonary bypass showed no superiority of inhalational agents over total intravenous anesthesia with opioids and benzodiazepines preventing phases of superficial anesthesia, but a marked advantage for the postoperative ventilation time compared with total intravenous anesthesia.

Novel Mapping Method for the Intraoperative Neurophysiologic Monitoring of Sexual Function During Prostate Surgery

The occurrence of urinary incontinence and erectile dysfunction after surgical treatment for prostate cancer is a significant and lingering problem. The aim of this study is to revise and improve older techniques of intraoperative cavernous nerve mapping already in use to improve accuracy and reliability. We prospectively studied this technique in 12 patients suffering from prostate cancer. Inhalation or intravenous anesthetic regimen was used with nondepolarizing muscle relaxants. Stimulation protocol was 30 Hz, 0.2 ms, 10 to 20 mA intensity and a maximum duration of 30 seconds. Recording was performed with a system for measuring pressure changes using a stainless steel needle electrode inside the cavernous bodies. Stimulation was systematically performed at three distinct moments during the surgery at various points. An increase or decrease in pressure of 4 cm of H20 in the cavernous bodies was considered a positive result and negative response when no changes occurred after 30 seconds of continuous stimulation. Of patients, 91.6% had positive responses to initial stimulation. The anesthetic regimen did not appear to significantly influence the responses in our series. In light of the results of this study, the stimulation of the cavernous nerves may be a viable technique in the right context, which includes good patient selection (young patients with a localized tumor and with preserved potency). The major limitation is that mapping techniques are useful to localize functional nerves, but not to monitor function in a continuous manner.

The anesthetic effects of small dose of midazolam or ketamine used for intemperants′ endoscopy

Objective To explore the safe and effective intravenous anesthetic regimen for intemperants′ painless endoscopy. Methods 120 cases of intemperants, aged 25-65 years old, ASA grade Ⅰ or Ⅱ , were randomly divided into 3 groups (n=40): sulfentanyl group (group S), midazolam and sulfentanyl group(group MS), ketamine and sulfentanyl group (group KS). Group S were intravenous injected with sufentanil 0.1 μg/kg, propofol 1-2 mg/kg, etomidate 0.1 mg/kg. Group MS and group KS were additional intravenous injected with midazolam 0.01 mg/kg and ketamine 0.1 mg/kg on the basis of Group S respectively. The occurrence of hypoxia, cough, body movement and blood pressure were recorded, the use of vasoactive drugs and the recovery time were also recorded. Results There are no statistical significant difference of age, gender, and testing time among the three groups (P>0.05). Compared with the group S, the total dose of propofol, the incidence of hypoxemia and hypotension, the incidence of body movement and cough reaction in group MS and group KS were all lower (P 0.05). Conclusions Small doses of midazolam or ketamine combined with sulfentanyl, propofol and etomidate are safe and effective in the process of anesthesia during endoscopic diagnosis and treatment of intemperants. Key words: Midazolam/AD; Ketamine/AD; Sufentanil/AD; Gastroscopy; Anesthesia; Alcoholics

Comparison of two intravenous anesthetic infusion regimens for alfaxalone in cats

ObjectiveTo compare the performance of an alfaxalone constant rate intravenous (IV) infusion versus a 3-step IV infusion, both following a loading dose, for the maintenance of a target plasma alfaxalone concentration of 7.6 mg L–1 (effective plasma alfaxalone concentration for immobility in 99% of the population) in cats. Study designProspective randomized crossover study. AnimalsA group of six healthy, adult male neutered cats. MethodsCatheters were placed in a jugular vein for blood sampling and in a medial saphenous vein for drug administration. An IV bolus of alfaxalone (2 mg kg–1) was administered, followed by either 0.2 mg kg−1 minute−1 for 240 minutes (single infusion; SI) or 0.4 mg kg−1 minute−1 for 10 minutes, then 0.3 mg kg−1 minute−1 for 30 minutes, and then 0.2 mg kg−1 minute−1 for 200 minutes (3-step infusion; 3-step). Plasma alfaxalone concentration was measured at six time points during the infusions. Measures of performance were calculated for each infusion regimen and compared using the paired Wilcoxon signed-rank test. ResultsMedian (range) absolute performance error, divergence, median prediction error and wobble were 15 (8–19)%, −8 (−12 to −6)% hour−1, −12 (−19 to −7)% and 10 (8–19)%, respectively, in the SI treatment, and 6 (2–16)%, 0 (−13 to 2)% hour−1, 1 (−16 to 4)% and 4 (3–6)% respectively, in the 3-step treatment and were significantly smaller in the 3-step treatment than in the SI treatment. Conclusion and clinical relevanceAfter IV administration of a bolus dose, a 3-step infusion regimen can better maintain stable plasma alfaxalone concentrations close to the target concentration than a single constant rate infusion.

Anaesthetic and cardiopulmonary evaluation following xylazine-Diazepam-ketamine-propofol administration with or without local infiltration analgesia using mepivacaine during inguinal castration in Donkeys

The present study was performed to investigate the cardiopulmonary responses and hypoalgesic efficacy of diazepam/ketamine anaesthesia induction followed by xylazine-propofol infusion alone (XDKP) or with a local infiltration of mepivacaine (XDKPM) for inguinal castration in donkeys. A 10 male adult donkeys were assigned to two groups (XDKP and XDKPM). Donkeys were sedated by xylazine then anaesthesia was inducted with followed by diazepam/ketamine. Anaesthesia was maintained by propofol infusion 0.1 mg/kg/h. XDKPM group, mepivacaine 2% were locally infiltrated on each side and two min before surgical incision. Both group got smooth induction and recovery. The pain scale scores showed a significant higher compared to baseline in both groups. In conclusion, a combination of XDKP is balanced total intravenous anaesthesia regimen with cardiopulmonary stability in donkeys undergoing inguinal castration. Keywords: xylazine, propofol, mepivacaine, inguinal castration, donkey

How to design intravenous anesthetic dose regimens based on pharmacokinetics and pharmacodynamics principles

How to design intravenous anesthetic dose regimens based on pharmacokinetics and pharmacodynamics principles

Organ Protection by Volatile Anesthetics in Non-Coronary Artery Bypass Grafting Surgery

The cardioprotective properties of volatile anesthetics have been widely demonstrated by numerous randomized studies and meta-analyses in the setting of cardiac surgery, above of all during coronary artery bypass grafting procedures. Recently, conflicting results have been presented in cardiac non-coronary artery bypass grafting surgery. Unfortunately, despite the existence of a great number of studies comparing a total intravenous anesthetic regimen with an inhalational regimen, at present there are no randomized studies presenting data regarding mortality and important outcomes, such as myocardial infarction, in non-cardiac surgery. In this review we analyze and present the results of the most recent and important studies regarding anesthetic preconditioning in cardiac and in noncardiac surgery. Furthermore, we focus on the emerging data from animal experiments, discussing in particular the molecular mechanisms underlying anesthetic preconditioning.

A comparison of volatile and non volatile agents for cardioprotection during on‐pump coronary surgery

A randomised study of 414 patients undergoing coronary artery surgery with cardiopulmonary bypass was conducted to compare the effects of a volatile anaesthetic regimen with either deesflurane or sevoflurane, and a total intravenous anaesthesia (TIVA) regimen on postoperative troponin T release. The primary outcome variable was postoperative troponin T release, secondary outcome variables were hospital length of stay and 1-year mortality. Maximal postoperative troponin T values did not differ between groups (TIVA: 0.30 [0.00-4.79] ng x ml(-1) (median [range]), sevoflurane: 0.33 [0.02-3.68] ng x ml(-1), and desflurane: 0.39 [0.08-3.74] ng x ml(-1)). The independent predictors of hospital length of stay were the EuroSCORE (p < 0.001), female gender (p = 0.042) and the group assignment (p < 0.001). The one-year mortality was 12.3% in the TIVA group, 3.3% in the sevoflurane group, and 6.7% in the desflurane group. The EuroSCORE (p = 0.003) was the only significant independent predictor of 1-year mortality.

QS397. Comparison of Inhaled and Intravenous Anesthetic Regimens on Hemodynamics and Inflammation in a Porcine Model of Goal-Directed Resuscitation of Hemorrhagic Shock

Introduction: Previous studies have suggested that a ketamine-based total intravenous anesthetic (TIVA) regimen is superior to an inhaled anesthetic by producing fewer adverse effects. While the use of TIVA has been documented in elective operations, there is limited data on its performance during traumatic shock. The purpose of this study was to evaluate the differential effects of an inhalational anesthetic with a TIVA regimen in the setting of uncontrolled hemorrhagic shock secondary to an induced Grade V liver injury.

Successful Intraoperative Spinal Cord Monitoring During Scoliosis Surgery Using a Total Intravenous Anesthetic Regimen Including Dexmedetomidine

Intraoperative neurophysiological monitoring (IONM) during corrective spinal surgery is widely used. Because of the possible interference with the recording of evoked potentials by inhalational anesthetics, total intravenous anesthetic (TIVA) regimens have been advocated. TIVA regimens may be difficult to use in pediatric populations due to metabolic factors. We report on the results of multimodality IONM during 18 cases in which a TIVA regimen incorporating dexmedetomidine (Precedex, Hespira, Lake Forest, IL) was used. Monitoring techniques included sensory (SSEP) and motor evoked potentials (MEP), as well as pedicle screw stimulation. SSEPs were maintained within an acceptable range of baseline amplitude (50%) and latency (10%), and MEPs remained elicitable throughout each case. We therefore found that the anesthetic regimen did not significantly interfere with any of the monitoring modalities used and conclude that IONM in the presence of dexmedetomidine is feasible under appropriate conditions.

Intraoperative Motor-evoked Potential Monitoring in Scoliosis Surgery: Comparison of Desflurane/Nitrous Oxide With Propofol Total Intravenous Anesthetic Regimens

A prospective, randomized study in a large general hospital setting. During spinal surgery, monitoring motor-evoked potentials (MEPs) is a means of assessing the intraoperative integrity of corticospinal pathways. However, MEPs are known to be sensitive to the effects of anesthetic agents. To compare the use of desflurane or total intravenous anesthetic regimens (TIVA) with multipulse cortical stimulation for intraoperative monitoring (IOM). Twenty consecutive patients (10 in each arm) undergoing scoliosis correction surgery were randomly assigned to 2 equal groups receiving desflurane or TIVA. Inhalational anesthesia was maintained using 66% nitrous oxide in oxygen and a mean end-tidal desflurane concentration of 3.4%. For TIVA, continuous intravenous infusion of propofol was used. For analgesia, fentanyl and morphine were given when required for both groups. Cortical stimulation was achieved with 2 bipolar direct current stimulators connected in parallel by jumper cables. Five equivalent pulses 0.5 ms in duration at 4 ms intervals were delivered at C1C2 positions. MEP recordings were made in the abductor hallucis (AH) and tibialis anterior (TA) with needle electrodes. Reproducible MEPs were obtained throughout the operation in all 20 cases, with up to 80 mA per stimulator. Before insertion of pedicle screws, mean MEP amplitudes (SD) obtained were 85 (19) and 21.7 (10.8) mV for AH and TA, respectively, using desflurane. With TIVA, amplitudes were 56.7 (28.4) and 59.1 (24.5) mV, respectively. Both muscle MEP amplitudes were significantly different using different anesthetic regimens (P < 0.05 for all). AH MEP amplitudes obtained with desflurane were significantly larger than TA amplitudes (P < 0.0001). No complications were reported intraoperatively and postoperatively. This is the first study comparing the use of desflurane and TIVA showing that both anesthetic regimens allowed successful intraoperative monitoring useage throughout the procedures. For MEP recording, the AH was the preferred muscle with a desflurane anesthetic regimen.

THIS ARTICLE HAS BEEN RETRACTED: Early recovery, cognitive function and costs of a desflurane inhalational vs. a total intravenous anaesthesia regimen in long‐term surgery

Background: The purpose of the study was to compare time of recovery, return of cognitive function, post‐anaesthetic care unit (PACU) stay and costs of a propofol/remifentanil (TIVA) with a desflurane/fentanyl‐based anaesthesia (desflurane group) in surgical procedures lasting more than 150 min.Methods: Forty‐nine patients undergoing elective abdominal prostatectomy were allocated randomly to receive bispectal index (BIS)‐controlled desflurane/fentanyl (n = 24) or propofol/remifentanil (n = 25). Awakening, clinical recovery, direct drug acquisition and post‐operative pain treatment were documented. Cognitive skills were tested using the Mini‐Mental Status (MMST) test.Results: Extubation was significantly faster with desflurane (6.9 ± 3.5 min) than with TIVA (11.2 ± 4.0 min) as well as times for stating name and date of birth (desflurane: 6.1 ± 3.9 and 6.6 ± 4.0 min; TIVA: 12.4 ± 11.5 min and 13.4 ± 11.3 min). There were no significant differences in PACU discharge times or MMS scores between the groups. Significantly more patients suffered post‐operative nausea and vomiting (PONV) in the desflurane (33% vs. 0%) than the TIVA group. Overall costs were significantly higher in the TIVA (58.8 ± 11.6 €) than in the desflurane group (35.0 ± 5.7 €).Conclusion: Patients undergoing prolonged surgical procedures showed a faster early recovery after desflurane/fentanyl than using TIVA, whereas stay in the PACU and recovery of cognitive function were similar in both groups. Costs of a TIVA regimen were significantly higher than using a desflurane‐based anaesthesia technique.

This Month in Anesthesiology

This Month in Anesthesiology

Pharmacologic and physiologic influences affecting sensory evoked potentials: implications for perioperative monitoring.

Pharmacologic and physiologic influences affecting sensory evoked potentials: implications for perioperative monitoring.

Textbook of Intravenous Anesthesia

Textbook of Intravenous Anesthesia