Alternatives to remifentanil for the analgesic component of total intravenous anaesthesia: a narrative review.

Propfol-remifentanil-based total intravenous anaesthesia has dominated recent clinical practice due to its favourable pharmacokinetic profile. Interruption in remifentanil supply has presented an opportunity to diversify or even avoid the use of opioids and consider adjuncts to propofol-based total intravenous anaesthesia. Propofol, while a potent hypnotic, is not an effective analgesic. The administration of opioids, along with other adjuncts such as α-2 adrenoceptor agonists, magnesium, lidocaine, ketamine and nitrous oxide provide surgical anaesthesia and avoids large doses of propofol being required. We provide an overview of both target-control and manual infusion regimes for the alternative opioids: alfentanil, sufentanil and fentanyl. The optimal combination of hypnotic-opioid dose, titration sequence and anticipated additional postoperative analgesia required depend on the chosen combination. In addition, we include a brief discussion on the role of non-opioid adjuncts in total intravenous anaesthesia, suggested doses and expected reduction in propofol dose.

Different effects of intravenous and local anesthesia in patients undergoing ultrasound-guided radiofrequency ablation of thyroid nodules: a prospective cohort study.

PURPOSE: To compare the efficacy and safety of intravenous anesthesia (IV) with local anesthesia (LA) in patients undergoing ultrasound (US)-guided radiofrequency ablation (RFA) of thyroid nodules. METHODS: 50 patients with American Society of Anesthesiologists classification grades I-II undergoing US-guided thyroid RFA were enrolled and randomly (1:1) divided into IV (conscious sedation with Ramsay Sedation Scale [RSS] scores of 2-3 with an anesthesiologist) and LA (subcutaneous anesthesia with lidocaine without an anesthesiologist) groups. Pre-, intra- and post-procedural blood pressure (BP) (SBP0/DBP0, SBP1/DBP1, and SBP2/DBP2), intra- and post-procedural pain (NRS1 and NRS2), ablated area volume, treatment time and adverse events were analyzed and compared. RESULTS: Age, sex, weight, number, nature, volume of nodules, and SBP0/DBP0 showed no difference between both groups. 11 and 0 patients' SBP1/DBP1 were elevated in the LA and IV groups. NRS1 differed between both groups. 6 patients in the LA group had moderate or severe pain, but none in the IV group. No between-group difference in SBP2/DBP2, NRS2, ablation completion rate and ablated volume was noted. The median procedure duration differed from 1109 (176) s in IV group and 723 (227) s in LA groups. There was no increased incidence of adverse events in IV group. CONCLUSIONS: IV with RSS scores of 2-3 maintained intra-procedural BP and relieved intra-procedural pain better, without affecting the ablation efficacy and increasing complications. Despite increased treatment time, IV is a potential option for patients undergoing US-guided RFA of thyroid nodules.

WALANT versus intravenous regional anesthesia for carpal tunnel syndrome: a randomized clinical trial

ABSTRACT BACKGROUND: There are several anesthetic techniques for surgical treatment of carpal tunnel syndrome (CTS). Results from this surgery using the "wide awake local anesthesia no tourniquet" (WALANT) technique have been described. However, there is no conclusive evidence regarding the effectiveness of the WALANT technique, compared with the usual techniques. OBJECTIVE: To evaluate the effectiveness of the WALANT technique, compared with intravenous regional anesthesia (IVRA; Bier's block), for surgical treatment of CTS. DESIGN AND SETTING: Randomized clinical trial, conducted at Hospital Alvorada Moema and the Discipline of Hand Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo (SP), Brazil. METHODS: Seventy-eight patients were included. The primary outcome was measurement of perioperative pain through a visual analogue scale (VAS). The secondary outcomes were the Boston Questionnaire score, Hospital Anxiety and Depression Scale (HADS) score, need for use of analgesics, operating room times, remission of paresthesia, failures and complications. RESULTS: The WALANT technique (n = 40) proved to be superior to IVRA (n = 38), especially for controlling intraoperative pain (0.11 versus 3.7 cm; P < 0.001) and postoperative pain (0.6 versus 3.9 cm; P < 0.001). Patients spent more time in the operating room in the IVRA group (59.5 versus 46 minutes; P < 0.01) and needed to use more analgesics (10.8 versus 5.7 dipyrone tablets; P = 0.02). Five IVRA procedures failed (5 versus 0; P = 0.06). CONCLUSIONS: The WALANT technique is more effective than IVRA for CTS surgery.

WALANT versus intravenous regional anesthesia for carpal tunnel syndrome: a randomized clinical trial.

BACKGROUND: There are several anesthetic techniques for surgical treatment of carpal tunnel syndrome (CTS). Results from this surgery using the "wide awake local anesthesia no tourniquet" (WALANT) technique have been described. However, there is no conclusive evidence regarding the effectiveness of the WALANT technique, compared with the usual techniques. OBJECTIVE: To evaluate the effectiveness of the WALANT technique, compared with intravenous regional anesthesia (IVRA; Bier's block), for surgical treatment of CTS. DESIGN AND SETTING: Randomized clinical trial, conducted at Hospital Alvorada Moema and the Discipline of Hand Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo (SP), Brazil. METHODS: Seventy-eight patients were included. The primary outcome was measurement of perioperative pain through a visual analogue scale (VAS). The secondary outcomes were the Boston Questionnaire score, Hospital Anxiety and Depression Scale (HADS) score, need for use of analgesics, operating room times, remission of paresthesia, failures and complications. RESULTS: The WALANT technique (n = 40) proved to be superior to IVRA (n = 38), especially for controlling intraoperative pain (0.11 versus 3.7 cm; P < 0.001) and postoperative pain (0.6 versus 3.9 cm; P < 0.001). Patients spent more time in the operating room in the IVRA group (59.5 versus 46 minutes; P < 0.01) and needed to use more analgesics (10.8 versus 5.7 dipyrone tablets; P = 0.02). Five IVRA procedures failed (5 versus 0; P = 0.06). CONCLUSIONS: The WALANT technique is more effective than IVRA for CTS surgery.

Analgesic effect of magnesium sulfate during total intravenous anesthesia: randomized clinical study.

INTRODUCTION AND OBJECTIVE: Opioids have usually been used as intraoperative analgesic components, regardless of the many adverse effects they are associated with, such as nausea, vomiting, respiratory depression, and hyperalgesia. Several approaches have been investigated to reduce doses used, and magnesium sulfate has been shown to be a valuable analgesic adjunct. The main objective of the present trial was to evaluate the effectiveness of magnesium sulfate as the chief intraoperative analgesic, and the secondary objectives were to assess propofol consumption, postoperative analgesia, and intraoperative hemodynamic stability. METHODS: In this prospective, double-blind trial, 50 patients scheduled to undergo post-bariatric abdominoplasty under general intravenous anesthesia were divided into two groups, to receive remifentanil or magnesium sulfate as intraoperative analgesic. Fentanyl 1 µg kg-1 was the rescue analgesic. RESULTS: Among the patients in the group receiving Magnesium Sulfate (MSG), 64% did not need supplemental analgesia and none of the patients in the Remifentanil Group (RG) required fentanyl. MSG patients showed propofol consumption 36.6% higher (guided by the Bispectral Index - BIS). MSG patients consumed significantly less ephedrine (mean ± SD) than RG patients, respectively 1.52 ± 4.38 mg and 10 ± 10.39 mg, p < 0.001. Mean values of blood concentrations of magnesium were comparable to values previously described in the literature. CONCLUSION: Magnesium sulfate is a safe and effective option for intraoperative analgesia, when avoiding or decreasing opioid use is required.

The effect of wide-awake anesthesia, intravenous regional anesthesia, and infraclavicular brachial plexus block on cost and clinical scores of patients undergoing hand surgery.

The aim of our study was to compare the clinical results and costs of wide-awake local anesthesia no tourniquet (WALANT), intravenous regional anesthesia (IVRA), and infraclavicular brachial plexus block (IC-BPB). The patients were divided into WALANT, IVRA, IC-BPB groups, each with 50 patients. Demographic information, induction time, use of sedation, number of patients who were converted to general anesthesia, time in postanesthesia care unit (PACU), amount of bleeding during surgery, presence of tourniquet pain, hand motor function during surgery, time to onset of postanesthesia pain, discharge time, complications, and anesthesia costs were compared. Sedation was given to 12 IC-BPB patients, 9 IVRA patients and 5 WALANT patients. Of these patients, 6 undergoing IC-BPB, 5 undergoing IVRA and 4 undergoing WALANT were converted to general anesthesia (p = 0.80). PACU time and anesthesia costs were the least in the WALANT group, followed by the IVRA group (p < 0.001, p < 0.001). Intraoperative active voluntary movements were best preserved in the WALANT group; however, bleeding was highest in the WALANT group (p < 0.001, p < 0.001). Tourniquet pain was the higher in the IVRA groups, while postoperative pain in the surgical area developed the fastest in this same group (p = 0.029, p < 0.001). Time to discharge was similar in WALANT and IVRA groups, and the longest in the IC-BPB (p < 0.001) group. There was no difference among the groups in terms of patient satisfaction (p = 0.085, p = 0.242 for the first and second survey question). In the current study, WALANT appears to be a suitable alternative to IVRA and IC-BPB methods, with better preservation of active intraoperative movement, lower cost, and shorter time spent in PACU at the expense of higher bleeding.

The effect of ketamine on depth of hypnosis indices during total intravenous anesthesia-a comparative study using a novel electroencephalography case replay system.

Ketamine may affect the reliability of electroencephalographic (EEG) depth-of-hypnosis indices as it affects power in high-frequency EEG components. The purpose of this study was to compare the effects of ketamine on three commonly-used depth-of-hypnosis indices by extending our EEG simulator to allow replay of previously-recorded EEG. Secondary analysis of previously-collected data from a randomized controlled trial of intravenous anesthesia with ketamine: Group 0.5 [ketamine, 0.5 mg kg-1 bolus followed by a 10 mcg kg-1 min-1 infusion], Group 0.25 [ketamine, 0.25 mg kg-1 bolus, 5 mcg kg-1 min-1 infusion], and Control [no ketamine]. EEG data were replayed to three monitors: NeuroSENSE (WAV), Bispectral Index (BIS), and Entropy (SE). Differences in depth-of-hypnosis indices during the initial 15 min after induction of anesthesia were compared between monitors, and between groups. Monitor agreement was evaluated using Bland-Altman analysis. Available data included 45.6 h of EEG recordings from 27 cases. Ketamine was associated with higher depth-of-hypnosis index values measured at 10 min (BIS, χ2 = 8.01, p = 0.018; SE, χ2 = 11.44, p = 0.003; WAV, χ2 = 9.19, p = 0.010), and a higher proportion of index values > 60 for both ketamine groups compared to the control group. Significant differences between monitors were not observed, except between BIS and SE in the control group. Ketamine did not change agreement between monitors. The ketamine-induced increase in depth-of-hypnosis indices was observed consistently across the three EEG monitoring algorithms evaluated. The observed increase was likely caused by a power increase in the beta and gamma bands. However, there were no lasting differences in depth-of-hypnosis reported between the three compared indices.

Patients' Perspective on Carpal Tunnel Release with WALANT or Intravenous Regional Anesthesia.

BACKGROUND: The authors conducted a prospective study to compare patients' intraoperative experience of open carpal tunnel release under "wide awake, local anesthesia, no tourniquet" (WALANT) on the one hand and intravenous regional anesthesia on the other. The authors hypothesized that WALANT would offer a better intraoperative experience than intravenous regional anesthesia. METHODS: Twenty-four patients with bilateral carpal tunnel syndrome had one hand operated on using WALANT and the contralateral hand with the intravenous regional anesthesia method. At the postoperative second hour, patients completed a questionnaire to quantify their pain levels on a numerical rating scale and compare the operation with dental procedures. They were also asked about their expectations and feelings about reoperation with the anesthesia methods. The results were compared for the two anesthesia methods. RESULTS: There were no significant differences between numerical rating scale pain values during anesthetic administration or for surgical site pain on the WALANT and intravenous regional anesthesia sides. Patients reported moderate tourniquet pain for intravenous regional anesthesia sides. For WALANT sides, a significantly higher number of patients reported carpal tunnel release to be an easier procedure than dental procedures (91.6 percent WALANT and 37.5 percent intravenous regional anesthesia). For WALANT sides, a significantly higher number of patients reported carpal tunnel release to be an easier procedure than they expected (91.6 percent WALANT and 50 percent intravenous regional anesthesia). For the reoperation, 83.3 percent of patients preferred WALANT, 8.3 percent preferred intravenous regional anesthesia, and 8.3 percent reported no preference. CONCLUSIONS: WALANT offered a better intraoperative experience. Tourniquet pain, preoperative preparation basics, and the extended anesthesia duration are likely the major drawbacks of the intravenous regional anesthesia method.

Reducing preoperative anxiety with Child Life preparation prior to intravenous induction of anesthesia: A randomized controlled trial.

BACKGROUND: Induction of anesthesia can be stressful: Up to 60% of children suffer significant anxiety immediately before surgery. Anxiety is associated with higher postoperative analgesia requirements, higher incidence of emergence delirium, and detrimental effects on sleep and behavior. Child Life preparation includes role-play, expectation-setting, and teaching coping strategies. AIM : The aim of this trial was to determine whether preoperative Child Life preparation reduces anxiety prior to intravenous induction of anesthesia. METHODS: Children aged 3-10 years, with no known preexisting anxiety and no preoperative anxiolytics, undergoing elective day surgery lasting ≤ 2 hours, were enrolled in a randomized controlled trial. Each child's baseline anxiety was assessed in the anesthetic care unit, using the modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF, observational scores from 22.9, minimal anxiety, to 100, maximal anxiety) as the primary outcome. The child was randomly assigned to intervention (minimum 15 minutes Child Life preparation) or control (standard practice without Child Life preparation). Participants entered the operating room with one parent. A researcher (blinded to group allocation) scored the child's operating room anxiety using mYPAS-SF, up to the first attempt at intravenous cannulation. RESULTS: Fifty-nine children completed the study, aged median [interquartile range] 5 [3-7] years. Baseline mYPAS-SF anxiety was 29.2 [22.9-37.5] for all children, and operating room anxiety was 29.2 [22.9-49.0]. Operating room anxiety was higher than baseline in 16/31 (52%) children in the control group and 6/28 (21%) in the Child Life preparation group. ANCOVA revealed a significant effect of baseline mYPAS-SF anxiety and group on operating room anxiety (F = 10.31, P < .001, adjusted R2  = .24); individual parameter estimates indicated that Child Life preparation reduced operating room anxiety by 13.8 (95% CI 4.4-23.1) points compared to control, P = .005. CONCLUSION: A brief, targeted Child Life preparation session had a statistically significant effect on reducing preoperative anxiety prior to intravenous induction of anesthesia in young children, with no known preexisting anxiety. This effect may be clinically important and suggests that Child Life can be a valuable component of pediatric surgical care. Further research is required in specific populations.

Surgical Treatment of Distal Radius Fractures under the Ultrasound-Guided Brachial Plexus Block Performed by Surgeons.

Background: The upper limb surgery under the ultrasound-guided brachial plexus block is becoming popular due to its safety, effectiveness, and convenience. However, the uneven distribution of anesthesiologists become a social problem. Ultrasound-guided brachial plexus block by surgeons has been widespread especially in hand surgeons. We report the surgical treatment of distal radius fractures under the ultrasound-guided brachial plexus block performed by surgeons in our hospital. Methods: The subjects were 101 patients (41 males and 60 females, average age 61.6 years) who underwent surgery for distal radius fractures under ultrasound-guided brachial plexus block administered by orthopedists at our university or related facilities between January 2014 and June 2016. Brachial plexus block was administered through the supraclavicular approach. The time from initiation of anesthesia to initiation of surgery, mean operative time, the presence or absence of additional anesthesia (local infiltration anesthesia, intravenous anesthesia, and general anesthesia), and complications were evaluated. Results: The mean time from brachial plexus block to initiation of surgery was 35.7 (20-68) minutes, and the mean operative time was 90.5 (35-217) minutes. Surgery was completed with brachial plexus block alone in 62 patients (61.4%), and additional anesthesia was necessary in 39 patients (38.6%). Furthermore, general anesthesia was employed in 6 patients (5.9%). No serious complications occurred. Conclusions: According to our results, the operation could be completed with brachial plexus block alone and additional local infiltration anesthesia or intravenous anesthesia in 94.1% (95 cases). However, 6 cases (5.9%) shifted to general anesthesia. Although it needs training, we consider that hand surgery including distal radius fractures treatment under the ultrasound-guided brachial plexus block is possible. On the other hand, cooperation or a cooperative system with anesthesiologists is necessary for surgeons to administer this anesthesia.

Feasibility of Fully Automated Hypnosis, Analgesia, and Fluid Management Using 2 Independent Closed-Loop Systems During Major Vascular Surgery: A Pilot Study.

Automated titration of intravenous anesthesia and analgesia using processed electroencephalography monitoring is no longer a novel concept. Closed-loop control of fluid administration to provide goal-directed fluid therapy has also been increasingly described. However, simultaneously combining 2 independent closed-loop systems together in patients undergoing major vascular surgery has not been previously detailed. The aim of this pilot study was to evaluate the clinical performance of fully automated hypnosis, analgesia, and fluid management using 2 independent closed-loop controllers in patients undergoing major vascular surgery before implementation within a larger study evaluating true patient outcomes.

Adaptive smith predictor controller for total intravenous anesthesia automation

Anesthetic agent propofol needs to be administered at an appropriate rate to prevent hypotension and postoperative adverse reactions. To comprehend more suitable anesthetic drug rate during surgery is a crucial aspect. The main objective of this proposal is to design robust automated control system that work effi ciently in most of the patients with smooth BIS and minimum variations of propofol during surgery to avoid adverse post reactions and instability of anesthetic parameters. And also, to design advanced computer control system that improves the health of patient with short recovery time and less clinical expenditures. Unlike existing research work, this system administrates propofol as a hypnotic drug to regulate BIS, with fast bolus infusion in induction phase and slow continuous infusion in maintenance phase of anesthesia. The novelty of the paper lies in possibility to simplify the drug sensitivity-based adaption with infusion delay approach to achieve closedloop control of hypnosis during surgery. Proposed work uses a brain concentration as a feedback signal in place of the BIS signal. Regression model based estimated sensitivity parameters are used for adaption to avoid BIS signal based frequent adaption procedure and large off set error. Adaptive smith predictor with lead–lag fi lter approach is applied on 22 diff erent patients' model identifi ed by actual clinical data. The actual BIS and propofol infusion signals recorded during clinical trials were used to estimate patient's sensitivity parameters EC50 and λ. Simulation results indicate that patient's drug sensitivity parameters based adaptive strategy facilitates optimal controller performance in most of the patients. Results are obtained with proposed scheme having less settling time, BIS oscillations and small off set error leads to adequate depth of anesthesia. A comparison with manual control mode and previously reported system shows that proposed system achieves reduction in the total variations of the propofol dose. Proposed adaptive scheme provides better performance with less oscillation in spite of computation delay, surgical stimulations and patient variability. Proposed scheme also provides improvement in robustness and may be suitable for clinical practices.

Dreaming and awareness during dexmedetomidine- and propofol-induced unresponsiveness.

BACKGROUND: Experiences during anaesthetic-induced unresponsiveness have previously been investigated by interviews after recovery. To explore whether experiences occur during drug administration, we interviewed participants during target-controlled infusion (TCI) of dexmedetomidine or propofol and after recovery. METHODS: Healthy participants received dexmedetomidine (n=23) or propofol (n=24) in stepwise increments until loss of responsiveness (LOR1). During TCI we attempted to arouse them for interview (return of responsiveness, ROR1). After the interview, if unresponsiveness ensued with the same dose (LOR2), the procedure was repeated (ROR2). Finally, the concentration was increased 1.5-fold to achieve presumable loss of consciousness (LOC), infusion terminated, and the participants interviewed upon recovery (ROR3). An emotional sound stimulus was presented during LORs and LOC, and memory for stimuli was assessed with recognition task after recovery. Interview transcripts were content analysed. RESULTS: Of participants receiving dexmedetomidine, 18/23 were arousable from LOR1 and LOR2. Of participants receiving propofol, 10/24 were arousable from LOR1 and two of four were arousable from LOR2. Of 93 interviews performed, 84% included experiences from periods of unresponsiveness (dexmedetomidine 90%, propofol 74%). Internally generated experiences (dreaming) were present in 86% of reports from unresponsive periods, while externally generated experiences (awareness) were rare and linked to brief arousals. No within drug differences in the prevalence or content of experiences during infusion vs after recovery were observed, but participants receiving dexmedetomidine reported dreaming and awareness more often. Participants receiving dexmedetomidine recognised the emotional sounds better than participants receiving propofol (42% vs 15%), but none reported references to sounds spontaneously. CONCLUSION: Anaesthetic-induced unresponsiveness does not induce unconsciousness or necessarily even disconnectedness. CLINICAL TRIAL REGISTRATION: NCT01889004.

[Effect of ear point embedding on plasma and effect site concentrations of propofol-remifentanil in elderly patients after target-controlled induction].

OBJECTIVE: To observe the clinical effect of ear point embedding on plasma and effect site concentrations of propofol-remifentanil in elderly patients who underwent abdominal external hernia surgery at the time of consciousness and pain disappearing by target-controlled infusion (TCI) and bispectral index (BIS). METHODS: Fifty patients who underwent elective abdominal hernia surgery were randomly assigned into an observation group and a control group, 25 cases in each one. In the observation group, 30 minutes before anesthesia induction, Fugugou (Extra), Gan (CO12), Pizhixia (AT4), and Shenmen (TF4) were embedded by auricular needles until the end of surgery, 10 times of counter press each point. In the control group, the same amount of auricular tape was applied until the end of surgery at the same points without stimulation 30 minutes before anesthesia induction. Patients in the two groups were given total intravenous anesthesia, and BIS was monitored by BIS anesthesia depth monitor. Propofol was infused by TCI at a beginning concentration of 1.5µg/L and increased by 0.3µg/L every 30s until the patients lost their consciousness. After that, remifentanil was infused by TCI at a beginning concentration of 2.0µg/L and increased by 0.3µg/L every 30s until the patients had no body reaction to pain stimulation (orbital reflex). Indices were recorded, including mean arterial pressure (MAP), heart rate (HR) and the BIS values, at the time of T0 (entering into the operation room), T1 (losing consciousness) and T2 (pain relief), the plasma and effect site concentrations of propofol at T1, the plasma and effect site concentrations of remifentanil at T2. After surgery we recorded the total amounts of propofol and remifentanil, surgery time and anesthesia time. RESULTS: At T1 and T2, MAP and HR of the observation group were higher than those of the control group (P<0.05, P<0.01). At T1, the plasma and effect site concentrations of propofol in the observation group were significantly lower than those in the control group (P<0.05, P<0.01). At T2, the plasma and effect site concentrations of remifentanil in the observation group were significantly lower than those in the control group (P<0.05, P<0.01). There was no significant difference in BIS values at T1 and T2 between the two groups (bothP>0.05). There was no significant difference in operation time and anesthesia time between the two groups (bothP>0.05). The total amount of remifentanil in the observation group was significantly lower than that in the control group (P<0.01). There was no significant difference in the total amount of propofol between the two groups (P>0.05). CONCLUSIONS: Ear points embedding combined with propofol-remifentanil TCI could reduce the plasma and effect site concentrations of propofol and remifentanil and the total amount of remifentanil in elderly patients with extra-abdominal hernia surgery, and had the effect of assisting sedation and analgesia.

[Mechanism of acupoint transcutaneous electric stimulation on analgesic anesthesia in the patients undergoing general anesthesia anorectal operation].

OBJECTIVE: To observe the regulatory effects of acupoint electric stimulation on the analgesic substances and the relevant indices of nerve-immunity-endocrine system in the patients undergoing general anesthesia anorectal operation. METHODS: One hundred and fifty-six patients undergoing hemorrhoids and anal fistula operation were randomized into three groups, 146 cases were included in the analysis. In the No.1 group (48 cases), the conventional intravenous general anesthesia was applied. In the No.2 group (50 cases), besides the conventional intravenous general anesthesia, the acupoint transcutaneous electric stimulation was combined at Neiguan (PC 6), Shenmen (HT 7), Shangliao (BL 31) and Ciliao (BL 32). operation in the No.2 and No.3 groups were lower apparently than that in the No.1 group (P<0.05, P<0.01). CONCLUSIONS: During the general anesthesia anorectal operation, the acupoint transcutaneous electric stimulation achieves analgesic anesthesia through effectively promoting the release of body analgesic substance and reducing the stress level in the operation. With the comprehensive acupoint selection as Neiguan (PC 6) and Shenmen (HT 7) and the local acupoints, the therapeutic effects are better in comparison with the simple selection of local acupoints. In the No.3 group (48 cases), besides the conventional intravenous general anesthesia, the acupoint transcutaneous electric stimulation was combined at Shangliao (BL 31) and Ciliao (BL 32). The electric stimulation was maintained till the end of operation. The patients' saliva was collected 0.5 h before operation and 1 h after operation separately. The indices that reflect the body pain regulation and nerve-immune-endocrine secretion were detected, such as opiophin protein (OPI), secretory immunoglobulin A (SIgA), saliva amylase (sAA), cortisol (Cor) and tumor necrosis factor α (TNF-α). The pain degree was observed 1 h after operation. RESULTS: In the No.2 group, OPI after operation was higher than that before operation (P<0.05). The difference value of OPI in the No.2 group was higher apparently than that in the No.1 group and the No.3 group (both P<0.05). SIgA after operation was higher than that before operation in the No.1 group (P<0.05). The difference values of SIgA, sAA, Cor in the No.2 group were lower apparently than those in the No.1 group (P<0.05, P<0.01). TNF-αbefore and after operation and its difference value among the groups were not significant statistically (all P>0.05). The pain degrees in 1 h after.

[Influence of electroacupuncture pretreatment on intestinal function in the patients of colorectal cancer surgery].

OBJECTIVE: To observe the effects of electroacupuncture (EA) pretreatment on the intestinal function, inflammatory reaction and blood lactic acid in the patients of colorectal cancer surgery. METHODS: Sixty patients of colorectal cancer laparotomy at selective period, aged from 18 to 59 years old were selected. According toⅠ-Ⅲ grade of American Society of Anesthesiologists (ASA), the patients were randomized into group A (total intravenous anesthesia), group B[total intravenous anesthesia combined with EA pretreatment at Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39) on the right side] and group C[total intravenous anesthesia combined with EA pretreatment at Zhongwan (CV 12), Tianshu (ST 25), Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39) on the right side], 20 cases in each one. The total intravenous anesthesia was applied to all of the three groups. EA pretreatment was used one day before surgery and 30 min before surgery at corresponding acupoints in the group B and group C separately, 30 min each time. After surgery, the recovery time of bowel sound, the recovery time of flatus, the recovery time of defecation, the duration of diet fasting, the time of peritoneal drainage tube withdrawal and the total peritoneal drainage volume were observed in the three groups. The venous blood was collected to determine white blood cell count (WBC) and neutrophil count (NEUT) before surgery (T0), 24 h after surgery (T1) and on the 5th day after surgery (T2) separately. The arterial blood was collected to determine the level of lactic acid before surgery (TⅠ), after peritoneal douching (TⅡ) and 24 h after surgery (TⅢ)separately. RESULTS: The recovery time of bowel sound, the recovery time of flatus, the duration of diet fasting and the time of peritoneal drainage tube withdrawal in the group C were apparently earlier than those in the group A (all P<0.05). WBC and NEUT at T1 in the group C were apparently less than those in the group A (both P<0.05). The differences in lactic acid at TⅠ, TⅡ and TⅢ were not significant statistically in comparison of the three groups (all P>0.05). CONCLUSIONS: The total intravenous anesthesia combined with EA pretreatment at Zusanli (ST 36), Shangjuxu (ST 37), Xiajuxu (ST 39), Tianshu (ST 25) and Zhongwan (CV 12) reduce the recovery time of bowel sound, the recovery time of flatus, the duration of diet fasting and the time of peritoneal drainage tube withdrawal so as to improve the recovery of intestinal function, reduce WBC in 24 h after surgery and alleviate inflammatory reaction. This therapy has no influence on blood lactic acid.

A Review of Modern Control Strategies for Clinical Evaluation of Propofol Anesthesia Administration Employing Hypnosis Level Regulation.

Regulating the depth of hypnosis during surgery is one of the major objectives of an anesthesia infusion system. Continuous administration of Propofol infusion during surgical procedures is essential but it unduly increases the load of an anesthetist working in a multitasking scenario in the operation theatre. Manual and target controlled infusion systems are not appropriate to handle instabilities like blood pressure and heart rate changes arising due to interpatient and intrapatient variability. Patient safety, large interindividual variability, and less postoperative effects are the main factors motivating automation in anesthesia administration. The idea of automated system for Propofol infusion excites control engineers to come up with more sophisticated systems that can handle optimum delivery of anesthetic drugs during surgery and avoid postoperative effects. A linear control technique is applied initially using three compartmental pharmacokinetic and pharmacodynamic models. Later on, sliding mode control and model predicative control achieve considerable results with nonlinear sigmoid model. Chattering and uncertainties are further improved by employing adaptive fuzzy control and H∞ control. The proposed sliding mode control scheme can easily handle the nonlinearities and achieve an optimum hypnosis level as compared to linear control schemes, hence preventing mishaps such as underdosing and overdosing of anesthesia.