The excitatory transmission from basolateral nuclues of amygdala to nucleus accumbens shell regulates propofol self-administration through AMPA receptors.

Propofol addictive properties have been demonstrated in humans and rats. The glutamatergic transmission from basolateral nucleus of amygdala (BLA) to the nucleus accumbens (NAc) modulates reward-seeking behaviour; especially, NAc shell (NAsh) is implicated in reward-seeking response. Previous studies indicated the interactions between AMPA receptors (AMPARs) and dopamine D1 receptor (D1R) in NAc mediated drug addiction, but whether the circuit of BLA-to-NAsh and AMPARs regulate propofol addiction remains unclear. We trained adult male Sprague-Dawley rats for propofol self-administration to examine the changes of action potentials (APs) and spontaneous excitatory postsynaptic currents (sEPSCs) in the NAsh. Thereafter, optogenetic stimulation with adeno-associated viral vectors microinjections in BLA was used to explore the effect of BLA-to-NAsh on propofol self-administration behaviour (1.7 mg/kg/injection). The pretreatment effects with NBQX (0.25-1.0 µg/0.3 µl/site) or vehicle in the NAsh on propofol self-administration behaviour, the expressions of AMPARs subunits and D1R/ERK/CREB signalling pathway in the NAc were detected. The results showed that the number of APs, amplitude and frequency of sEPSCs were enhanced in propofol self-administrated rats. Propofol self-administration was inhibited in the NpHR3.0-EYFP group, but in the ChR2-EYFP group, there was a promoting effect, which could be weakened by NBQX pretreatment. NBQX pretreatment also significantly decreased the expressions of GluA2 subunit and D1R in the NAc but did not change the expressions of GluA1 and ERK/CREB signalling pathway. The evidence supports a vital role of BLA-to-NAsh circuit in regulating propofol self-administration and suggests this central reward processing may function through the interaction between AMPARs and D1R in the NAsh.

The effect of lidocaine intraoperative infusion on quality of postoperative sleep in patients undergoing thyroidectomy: a randomized controlled trial.

BACKGROUND: The incidence of thyroid nodules has increased significantly in recent years, and surgical removal is a common treatment. Postoperative sleep disturbance is still a serious problem in the current surgical environment. In this study, we explored whether intraoperative lidocaine infusion could improve the quality of sleep over 7 days and 30 days after surgery and postoperative recovery for patients undergoing thyroid surgery. METHODS: Seventy patients who underwent thyroid surgery from October 2020 to June 2021 were randomly assigned to the lidocaine or the normal saline group, 35 cases in each group. Patients enrolled in this study were randomized to receive either system lidocaine (a bolus of 1.5 mg·kg- 1, followed by an infusion of 2 mg·kg- 1·h- 1 until the end of the surgical procedure) or identical volumes and rates of normal saline. The primary endpoint was the Pittsburgh Sleep Quality Index (PSQI) scores. Secondary endpoints included intraoperative remifentanil consumption, whether there was a cough within 5 min after extubation and the cough scores, postoperative pain scores, the incidence of postoperative nausea and vomiting (PONV). RESULTS: Totally seventy cases were enrolled and eventually sixty-eight cases were analyzed. PSQI scores did not change significantly over time (F = 2.799, P = 0.069); also, there was no significant difference in PSQI scores between two groups in the entire 30 days follow-up period (F = 0.174, P = 0.678). Further, there was no interaction between the time points and the intervention (F = 0.649, P = 0.513). Similarly, intraoperative remifentanil consumption, the incidence of cough and postoperative pain scores, were comparable between the two groups (all P > 0.05); while patients in the lidocaine group showed significantly lower cough scores (P = 0.042) and lower incidence of PONV (P = 0.015). CONCLUSIONS: Systemic lidocaine infusion might not improve the sleep quality and reduce postoperative pain over 7 days or 30 days after the operation of patients who underwent thyroid surgery, but it can reduce postoperative complications and improve the quality of recovery. Furthermore, sleep quality of patients wasn't impaired significantly in the entire 30 days follow-up period after thyroid surgery compared with baseline values. TRIAL REGISTRATION: Registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn , identifier: ChiCTR2000039764, date: 08/11/2020).

Intravenous lidocaine simultaneously infused with sufentanil to accelerate gastrointestinal function recovery in patients after thoracolumbar surgery: a prospective, randomized, double-blind controlled study.

PURPOSE: Postoperative gastrointestinal dysfunction is one of the common complications of surgery, especially after surgery for a thoracolumbar spinal fracture. Intravenous lidocaine is a potential method to improve postoperative gastrointestinal function in surgical patients, reduce opioid use and shorten hospital stays. The purpose of this study is to explore the effect of intravenous lidocaine on the recovery of gastrointestinal function in patients after thoracolumbar surgery. METHODS: In this study, 48 eligible patients undergoing elective thoracolumbar spine fractures resection and internal fixation surgery were enrolled to receive intravenous injections of lidocaine in different concentrations during the perioperative period. Patients were randomly divided into three groups: control group (group A), low concentration of lidocaine group (group B) and high concentration of lidocaine group (group C), 16 patients in each group. First postoperative exhaust time, numbers of bowel sound at preoperative and postoperative 3, 6, 12, 24 h, pain scores at postoperative 0, 3, 6, 12, 24, 48 h, total sufentanil use in PACU and perioperative periods, postoperative hospital stay and analgesic remedy within postoperative 48 h were recorded and compared. The primary endpoints include: the time of first flatus passage after the operation, the number of bowel sounds per minute counted with stethoscope at 30 min before anesthesia induction and at 3, 6, 12 and 24 h postoperative. The secondary endpoints included: the pain scores at PACU (after entering into PACU), 3, 6, 12, 24 and 48 h postoperative, the amount of sufentanil administrated by intravenous push during operation and the numbers of patients needed rescuing sufentanil in PACU, and the numbers of patients needed administration of gastric motility drugs or non-steroidal analgesics at ward within 48 h postoperation, length of hospital stay (from the first day after surgery to discharge from hospital) and the incidence of adverse reactions. RESULTS: Compared with group A, the first postoperative exhaust time in group B and C occurred much earlier (23.3 ± 11.0 h vs. 16.0 ± 6.6 h, 16.6 ± 5.1 h, P < 0.05). Compared with preoperation, the numbers of bowel sound significantly increased at 24 h postoperatively in group B, while group B at 6 h and group C at 6 and 24 h postoperatively had significantly more active bowel sounds compared to group A (P < 0.05). There were no remarkable differences in VAS scores within 12 h postoperatively among three groups, and however, significantly lower VAS scores were found at 12, 24 and 48 h postoperatively in group C when comparing to Group A (p < 0.05). There was no statistical significance in the incidence of postoperative flatulence and nausea and vomiting, the number of patients needed rescuing sufentanil in PACU, the length of postoperative hospital stay and the number of patients requiring non-steroidal analgesics at ward within 48 h postoperation. CONCLUSIONS: Intravenous lidocaine infusion together with patient-controlled analgesia of sufentanil expedited the early recovery of gastrointestinal function and improved analgesic quality of sefentanyl in patients undergoing thoracolumbar surgeries.

Efficacy and safety of ciprofol vs. propofol for the induction and maintenance of general anaesthesia: A multicentre, single-blind, randomised, parallel-group, phase 3 clinical trial.

BACKGROUND: HSK3486 (ciprofol) is a 2,6-disubstituted phenol derivative that acts like propofol as an agonist at the gamma-aminobutyric acid-A (GABA A ) receptor. OBJECTIVE: To investigate the efficacy and safety of HSK3486 for general anaesthesia induction and maintenance. DESIGN: A single-blinded, randomised, parallel-group, phase 3 trial. SETTING: Involving 10 study centres, from November 24, 2020 to January 25, 2021. PATIENTS: A total of 129 patients undergoing nonemergency, noncardiothoracic, and nonneurosurgical elective surgery. INTERVENTION: Patients were randomly assigned at a 2:1 ratio into HSK3486 or propofol groups, to receive HSK3486 (0.4 mg kg -1 ) or propofol (2.0 mg kg -1 ) for induction before a maintenance infusion at initial rates of 0.8 and 5.0 mg kg -1 h -1 , and were adjusted to maintain a bispectral index (BIS) of 40-60 until the end of surgery. MAIN OUTCOME MEASURES: Noninferiority between the drugs was evaluated as the lower limit of the 95% confidence interval (CI) for the between-group difference in the success rate of anesthetic maintenance (primary outcome) >-8%. Secondary outcomes included successful anaesthetic induction, full alertness and spontaneous breathing recovery, time until leaving the postanaesthesia care unit and changes in BIS. Safety profiles were also measured. RESULTS: Of 129 enrolled patients, 128 completed the trial, with 86 in the HSK3486 group and 42 in the propofol group. The success rate for the maintenance of general anaesthesia was 100% for both groups, and noninferiority of HSK3486 was confirmed (95% CI -4.28% to 8.38%). No significant differences were found between the two groups of patients with regard to secondary outcomes (all P  > 0.05). There appeared to be a comparable incidence of treatment for emergency adverse events (TEAEs) (80.2% vs. 81.0%, P  = 1.000) and drug-related TEAEs (57.0% vs. 64.3%, P  = 0.451) in the HSK3486 and propofol groups. CONCLUSION: HSK3486 had a noninferior efficacy profile compared to propofol, exhibiting excellent tolerance. TRIAL REGISTRATION: Clinicaltrials.gov, identifier: NCT04511728.

Effect of lidocaine perioperative infusion on chronic postsurgical pain in patients undergoing thoracoscopic radical pneumonectomy.

BACKGROUND: Thoracoscopic radical pneumonectomy is associated with a high incidence of postoperative chronic pain. Studies on the benefits of lidocaine intravenous infusion during the perioperative period were still controversial in thoracoscopic surgery. METHODS: Sixty-four lung cancer patients scheduled for thoracoscopic radical pneumonectomy were randomly divided into two groups: normal saline group (control group) or lidocaine group. In the lidocaine group, 1.5 mg/kg lidocaine was administered during the anesthesia induction, and 2 mg·kg-1·h-1 lidocaine was continuously intravenous infused until the end of the surgery. After the surgery, a mixture of 2 µg/kg sufentanil and 10 mg/kg lidocaine was continuously intravenous infused by postoperative patient-controlled intravenous analgesia pump (100 ml). In the control group, the same volume of normal saline was administered according to the calculation of lidocaine during anesthesia induction, maintenance and postoperative patient-controlled intravenous analgesia. The primary outcome was the incidence of chronic postoperative pain at 3 months after the surgery. The secondary outcomes include the incidence of chronic postoperative pain at 6 months after the surgery; the effect of lidocaine on postoperative pain within the first 24 and 48 h; total amount of sufentanil administered during entire procedure and the number of PCA triggers within 48 h after surgery. RESULTS: Compared with the control group, the incidence of chronic pain at 3 months after the surgery was significantly lower (13 cases, 46.4% vs. 6 cases, 20.7%, p < 0.05), but no significant difference at 6 months between two group. The cumulative dosage of sufentanil in perioperative period was significantly lower (149.64 ± 18.20 µg vs. 139.47 ± 16.75 µg) (p < 0.05), and the number of PCA triggers (8.21 ± 4.37 vs. 5.83 ± 4.12, p < 0.05) was significantly greater in the control group. The NRS pain scores at 24 h (1.68 ± 0.72 vs. 1.90 ± 0.86) and 48 h (1.21 ± 0.42 vs. 1.20 ± 0.41) after the operation were no significant difference. CONCLUSION: Perioperative infusion lidocaine significantly reduced the number of PCA triggers and the incidence of chronic postoperative pain at 3 months after the thoracoscopic radical pneumonectomy. TRIAL REGISTRATION: http://www.chictr.org.cn : ChiCTR1900024759, frist registration date 26/07/2019.

Pruritus after continuous administration of epidural morphine for post-cesarean delivery analgesia: a case control study.

BACKGROUND: Pruritus is one of the most common side effects of epidural morphine administered for post-surgery analgesia, and pregnant women tend to be highly susceptible. The relative contributions of morphine concentration, local anesthetics, and level of pain to pruritus after epidural morphine for post-cesarean delivery analgesia remain unclear. Accordingly, the present study aimed to identify risk factors for pruritus after continuous administration of epidural morphine for post-cesarean delivery analgesia. METHODS: This case control study was based on routinely collected clinical data. Participants included women who had undergone cesarean section and adopted a patient-controlled analgesia pump for postoperative analgesia. A series of logistic regression analyses were performed. Interaction terms were added to explore the moderation effects of combined local anesthetics and pain level on associations between morphine concentration and pruritus. Robustness of the results was checked through sensitivity analysis using propensity scores matching approach. RESULTS: Higher morphine concentration, assisted reproductive treatment, and multipara and cesarean section history were significantly more prevalent in the pruritus group than in the control group. The probabilities of pruritus at morphine concentrations of 10, 15, 20, 25, 30 and 40 µg/mL increased sequentially from 0.05, 0.1, 0.2, 0.35, 0.54 to 0.84, respectively. The trend remained steep in the ropivacaine stratum and became flatter when combined with levobupivacaine. At mild pain combined with levobupivacaine, the incidence of pruritus increased from 0.33 (95% confidence interval [CI] 0.1-0.68) in the 10 µg/mL morphine group to 0.48 (95% CI 0.1-0.88) in the 40 µg/mL morphine group. In the stratum of moderate pain combined with levobupivacaine, the incidence increased from 0.4 (95% CI 0.04-0.92) to 0.56 (95% CI 0.03-0.98). The results in the sensitivity analysis were in consistent with above findings. CONCLUSIONS: Higher concentrations of morphine, multipara, and assisted reproductive treatment were factors associated with a higher probability of pruritus. Pain level or combined local anesthetics could moderate the association between morphine concentration and pruritus.

Effect of intravenous administration of lidocaine on the ED50 of propofol induction dose during gastroscopy in adult patients: A randomized, controlled study.

WHAT IS KNOWN AND OBJECTIVE: Propofol provides a prominent sedation effect in gastroscopy. However, sedation with propofol alone during gastroscopy might result in circulatory and respiratory depression. This study aimed to test the hypothesis that the addition of intravenous lidocaine to propofol-based sedation could decrease the ED50 of propofol induction dose during gastroscopy in adult patients while the respiratory and haemodynamic stability were not compromised. METHODS: Patients undergoing gastroscopy were randomly enrolled into lidocaine + propofol (L + P) group or normal saline + propofol (NS + P) group. Subjects were initially administered intravenous bolus of 1.5 mg/kg lidocaine in L + P group or equivalent volume of 0.9% saline in NS + P group. Anaesthesia was then induced with a single bolus of 1.0 µg sufentanil followed by injection of propofol in all patients. The induction dose of propofol for each individual patient was determined by the protocol of Dixon "up-and-down" method for both groups. The primary end point was the ED50 of propofol induction dose. RESULTS: Totally, 48 patients were enrolled and completed this study. Compared with the NS + P group, the ED50 of propofol induction dose was significantly reduced in the L + P group (2.01 mg/kg vs. 1.69 mg/kg) (U = 61.5, p < 0.001). WHAT IS NEW AND CONCLUSION: The addition of intravenous lidocaine significantly reduced the ED50 of propofol induction dose during gastroscopy in adult patients. TRIAL REGISTRATION: The present clinical trial was registered at http://www.chictr.org.cn/ (registration No. ChiCTR1900024025, 23 June 2019).

The propofol-sparing effect of intravenous lidocaine in elderly patients undergoing colonoscopy: a randomized, double-blinded, controlled study.

BACKGROUND: Propofol provides a prominent sedation effect in colonoscopy. However, anesthesia and sedation induced with propofol in the elderly might result in cardiopulmonary complications, especially when it is combined with opoids in the regimen. This study aimed to test the hypothesis that the addition of intravenous lidocaine to propofol-based sedation could decrease the overall propofol requirement in elderly patients during colonoscopy while the procedural sedation satisfaction and the hemodynamic stability were not compromised. METHODS: Ninety-two patients undergoing colonoscopy were randomly enrolled into lidocaine+propofol (L + P) group or normal saline+propofol (NS + P) groups. Subjects received intravenous bolus of 1.5 mg/kg lidocaine followed by 4 mg kg- 1 h- 1 lidocaine continuous infusion in L + P group or equivalent volumes of normal saline for boluses and infusion in NS + P group. Anesthesia was induced with 2.5 µg sufentanil followed by injection of 1.2 mg kg- 1 propofol in all patients. A single supplemental bolus of 0.6 mg kg- 1 propofol was administered whenever MOAA/S score > 1 or had body movement during the colonoscopy. The recorded primary endpoints included: the total amount of propofol administered during entire procedure, the supplemental amount of propofol after induction, and the frequencies of boluses of supplemental propofol. RESULTS: A total of 79 patients were included in the final analysis. Compared with NS + P group, the total amounts of propofol (induction plus supplemental) were no significant differences in L + P group; however, the required supplemental propofol was less (69.9 ± 39.2 mg vs. 51.5 ± 38.6 mg) (P = 0.039); the average frequencies of boluses of supplemental propofol given after induction were lower (2.1 ± 1.1 vs. 1.4 ± 0.9) (P = 0.003); the calculated "unit propofol" infusion rate was lower (0.18 ± 0.05 vs. 0.14 ± 0.04 mg kg- 1 min- 1) (P = 0.002). CONCLUSIONS: The addition of intravenous lidocaine to propofol-based sedation resulted in a remarked reduction of supplemental propofol in the elderly during colonoscopy. TRIAL REGISTRATION: The present clinical trial was registered at http://www.chictr.org.cn on 11th March 2019 (registration No. ChiCTR1900021818).

Warming efficacy of Ranger™ and FT2800 fluid warmer under different room temperatures and flow rates.

The comparison of the heating capabilities with different warming system between 3M™ Ranger™ warmer (3M) and FT2800 fluid warmer (FT) under different room temperatures and infusion rates, has been rarely reported previously. The study was then aimed to compare the warming efficacies of dry heat technology (3M) and coaxial warming system (FT) under different room temperatures and infusion rates, the advantages and disadvantages of both infusion systems would be compared to provide reference for clinical infusion practice. In the study, both target warming temperatures of 3M and FT warmer were set at 41 °C, fluid was administrated under 20, 22 and 24 °C room temperatures and drip rates of 60, 80, 100, 120, 140, 160, 200, 350 drops min-1. The fluid temperature at the outlet of the infusion tube (Toutlet) was measured and compared. The Toutlet of FT was higher than that of 3 M (P < 0.001) under different room temperatures. The Toutlet of FT increased with the room temperature raised (P < 0.05). As for 3M, Toutlet was lowest at 20 °C (P < 0.001) and no statistical difference of Toutlet was found between 22 and 24 °C (P = 0.667). Linear regression showed that the Toutlet of 3M increased with the speed up of drip rate, while the Toutlet of FT was decreased. The relationship between Toutlet & room temperature & drip rate for both 3M and FT warmers was calculated by a formula. 3M Ranger™ and FT2800 show different heating capabilities under different room temperatures and drip rates. 3M is more efficient at high flow rate while FT is more efficient at low flow rate. There is a formula relationship between Toutlet & room temperature & drip rate for both 3M and FT warmers.

Analyzing Electroencephalography (EEG) Waves Provides a Reliable Tool to Assess the Depth of Sevoflurane Anesthesia in Pediatric Patients.

BACKGROUND Studies have reported that BIS is unreliable in children because its algorithm provides misleading information about the actual depth of anesthesia. Raw EEG analysis provides direct neurophysiologic measurement of cerebral activity. The relationship between age and EEG has rarely been reported, thus the aim of the present study was to compare raw electroencephalography (EEG) among different age groups of surgical patients under general anesthesia with 1.0 MAC sevoflurane. MATERIAL AND METHODS We enrolled 135 patients aged 0-80 years old (ASA physical status I or II) undergoing surgery, who were divided into 6 groups: 1-12 months old (group 1), 1-3 years old (group 2), 3-6 years old (group 3), 6-18 years old (group 4), 18-65 years old (group 5), and 65-80 years old (group 6). Different raw EEG waves (alpha, delta, and theta) were compared for all subjects. RESULTS The BIS values in groups 1 to 6 were 52.2±12.7, 55.0±8.0, 44.5±7.3, 43.8±7.3, 44.2±6.2, and 49.1±6.2 respectively. Compared with groups 1 and 2 (52.2±12.7, 55.0±8.0), BIS values of groups 3, 4, and 5 (44.5±7.3, 43.8±7.3, 44.2±6.2, respectively) were lower (P<0.05). Theta frequency was observed in the 6 groups. The EEG frequencies in groups 1 to 6 were 6.0 (5.5-6.0), 6.0 (5.5-6.0), 6.0 (5.5-6.0), 6.0 (6.0-7.0), 6.3 (6.0-7.0), and 6.0 (5.1-6.0), respectively. Compared with group 6, EEG frequencies in groups 4 and 5 were higher (P<0.05). BIS value was significantly correlated with EEG frequency (R²=0.063, P<0.01). CONCLUSIONS Analyzing raw EEG waves provides more accurate judgement of depth of anesthesia, especially in pediatric cases in which monitors often provide misleading values.

Intravenous dexmedetomidine pre-medication reduces the required minimum alveolar concentration of sevoflurane for smooth tracheal extubation in anesthetized children: a randomized clinical trial.

BACKGROUND: It has been known that Dexmedetomidine pre-medication enhances the effects of volatile anesthetics, reduces the need of sevoflurane, and facilitates smooth extubation in anesthetized children. This present study was designed to determine the effects of different doses of intravenous dexmedetomidine pre-medication on minimum alveolar concentration of sevoflurane for smooth tracheal extubation (MACEX) in anesthetized children. METHODS: A total of seventy-five pediatric patients, aged 3-7 years, ASA physical status I and II, and undergoing tonsillectomy were randomized to receive intravenous saline (Group D0), dexmedetomidine 1 µg∙kg-1 (Group D1), or dexmedetomidine 2 µg∙kg-1 (Group D2) approximately 10 min before anesthesia start. Sevoflurane was used for anesthesia induction and anesthesia maintenance. At the end of surgery, the initial concentration of sevoflurane for smooth tracheal extubation was determined according to the modified Dixon's "up-and-down" method. The starting sevoflurane for the first patient was 1.5% in Group D0, 1.0% in Group D1, and 0.8% in Group D2, with subsequent 0.1% up or down in next patient based on whether smooth extubation had been achieved or not in current patient. The endotreacheal tube was removed after the predetermined concentration had been maintained constant for ten minutes. All responses ("smooth" or "not smooth") to tracheal extubation and respiratory complications were assessed. RESULTS: MACEX values of sevoflurane in Group D2 (0.51 ± 0.13%) was significantly lower than in Group D1 (0.83 ± 0.10%; P < 0.001), the latter being significantly lower than in Group D0 (1.40 ± 0.12%; P < 0.001). EC95 values of sevoflurane were 0.83%, 1.07%, and 1.73% in Group D2, Group D1, and Group D0, respectively. No patient in the current study had laryngospasm. CONCLUSION: Dexmedetomidine decreased the required MACEX values of sevoflurane to achieve smooth extubation in a dose-dependent manner. Intravenous dexmedetomidine 1 µg∙kg-1 and 2 µg∙kg-1 pre-medication decreased MACEX by 41% and 64%, respectively. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR): ChiCTR-IOD-17011601 , date of registration: 09 Jun 2017, retrospectively registered.

Tracheal extubation in deeply anesthetized pediatric patients after tonsillectomy: a comparison of high-concentration sevoflurane alone and low-concentration sevoflurane in combination with dexmedetomidine pre-medication.

BACKGROUND: Dexmedetomidine can facilitate a smooth extubation process and reduce the requirement of sevoflurane and emergence agitation when administrated perioperatively. We aimed to observe the extubation process and the recovery characteristics in pediatric patients undergoing tonsillectomy while anesthetized with either high-concentration sevoflurane alone or low-concentration sevoflurane combined with pre-medication of single dose of intravenous dexmedetomidine. METHODS: Seventy-five patients (ASA I or II, aged 3-7 years) undergoing tonsillectomy were randomized into three equal groups: to receive intravenous saline (Group D0), dexmedetomidine 1 µg/kg (Group D1), or dexmedetomidine 2 µg/kg (Group D2) approximately 10 min before anesthesia. Before the end of surgery, sevoflurane were adjusted to 1.5 times, 1.0 time and 0.8 times the minimal effective concentration in groups D0, D1 and D2, respectively. The sevoflurane concentration for each group was maintained for at least 10 min before the tracheal deep-extubation was performed. The extubation event, recovery characteristics and post-op respiratory complications were recorded. RESULTS: All tracheal tubes in three groups were removed successfully during deep anesthesia. Nine patients in Group D0, three patients in Group D1, and two patients in Group D2 required oral airway to maintain a patent airway after extubation. The frequency of oral airway usage in groups D1 and D2 were significantly lower than that in Group D0. The percentages of patients with ED and the requirements of fentanyl in groups D1 and D2 were also significantly lower than those in Group D0. The time from extubation to spontaneous eye opening in Group D2 was longer than that in groups D0 and D1. The times of post-anesthesia care unit discharge in groups D0 and D2 were longer than that in Group D1. No other respiratory complications and vomiting were observed. CONCLUSION: A single dose of intravenous dexmedetomidine as pre-medication in combination with low-concentration sevoflurane at the end of surgery provided safe and smooth deep extubation condition and it also lowered the emergence agitation in sevoflurane-anaesthetized children undergoing tonsillectomy. Preoperative dexmedetomidine at 1 µg/kg did not prolong postoperative recovery time. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR): ChiCTR-IOR-16008423 , date of registration: 06 may 2016.

The efficacy and safety of mivacurium in pediatric patients.

BACKGROUND: Mivacurium is the shortest acting nondepolarizing muscle relaxant currently available; however, the effect of different dosages and injection times of intravenous mivacurium administration in children of different ages has rarely been reported. This study was aimed to evaluate the muscle relaxant effects and safety of different mivacurium dosages administered over different injection times in pediatric patients. METHODS: Six hundred forty cases of pediatric patients, aged 2 m-14 years, ASA I or II, were divided into four groups (Groups A, B, C, D) according to the age class (2-12 m, 13-35 m, 3-6 years and 7-14 years) respectively, also each group were divided into four subgroups by induction dose (0.15, 0.2 mg/kg in 2-12 m age class; 0.2, 0.25 mg/kg in other three age classes), and mivacurium injection time (20 s, 40 s), totally 16 subgroups. Neuromuscular transmission was monitored with supramaximal train-of-four stimulation of the ulnar nerve. Radial artery blood (1 ml) was sampled to quantify plasma histamine concentrations before and 1, 4, and 7 min after mivacurium injection (P0, P1, P2 and P3). RESULTS: Five hundred sixty-two cases completed the study. There were no demographic differences within the four groups. The onset time of 0.2 mg/kg groups in 2-12 m aged patients were shorter than those of 0.15 mg/kg groups (189 ± 64 s vs. 220 ± 73 s, 181 ± 60 s vs. 213 ± 71 s, P <0.05), and the recovery times were no statistical differences. The T1 25% recovery time of 0.2 mg/kg in 3-6 years aged patients was shorter than that of 0.25 mg/kg group (693 ± 188 s vs. 800 ± 206 s, P <0.05). The onset and recovery times of mivacurium were not different in 13-35 m and 7-14 years aged patients. The plasma concentrations of histamine at P0, P1, P2 and P3 were not different within four groups. CONCLUSIONS: The induction dose and injection time of mivacurium had mostly insignificant effects on onset and recovery times. The main exception to this was that in 2-12 m aged patients, increasing the dose of mivacurium from 0.15 to 0.2 mg/kg accelerated the onset time by about 30 s. Mivacurium produced no significant release of histamine in any age group at the doses studied. TRIAL REGISTRATION: ClinicalTrials.gov Identifier- NCT02117401 , July 14, 2014. (Retrospectively registered).

Anatomic variations of neck vessels and the course of pediatric internal jugular veins.

BACKGROUND: Landmark-guided internal jugular vein cannulation is difficult for pediatric patients but useful, especially when ultrasound equipment is unavailable. Therefore, it is important to define the adjacent anatomic characteristics of the pediatric internal jugular vein. METHODS: In 210 children the course of the internal jugular vein, and common carotid and vertebral arteries was measured from the level of the cricoid cartilage to the supraclavicular area using ultrasound. RESULTS: From the level of the cricoid cartilage to the supraclavicular area, vessel diameter increased with internal jugular vein increasing by 12%, and common carotid and vertebral arteries increasing by 5% each. From the level of the cricoid cartilage to the supraclavicular area, the number of patients with a medial common carotid artery position relative to the internal jugular vein increased, whereas those with a lateral position decreased; the number of patients with nonoverlapped common carotid artery-internal jugular vein increased, and those with totally overlapped decreased. In contrast, the overlapping status of vertebral artery-internal jugular vein changes oppositely. More than 97.14% of the vertebral artery lies lateral to the internal jugular vein at these levels. The minimal vertebral artery-internal jugular vein depth decreased from 0.46±0.20 to 0.37±0.19 cm. The angle from the internal jugular vein line to the horizontal line of the body was 83.35±9.04 degrees. CONCLUSION: The common carotid artery and internal jugular vein are farther apart as one moves down the neck, whereas the vertebral artery and internal jugular vein are getting together. Additionally, the diameter of the internal jugular vein increased.

Can noninvasive hemoglobin measurement reduce the need for preoperative venipuncture in pediatric outpatient surgery?

BACKGROUND: Noninvasive measurements of hemoglobin in the pediatric perioperative setting could be helpful to avoid venipunctures in children. The present study aims to evaluate this by using a noninvasive device for hemoglobin determination. We compared noninvasively obtained hemoglobin with laboratory hemoglobin concentrations in children during their preoperative assessment. METHODS: In an observational study, 122 nonanemic children (age 4.2 ± 1.6 years) who were scheduled to undergo different surgical procedures under general anesthesia were included. In their preoperative preparations, single invasive blood samples for laboratory hemoglobin concentrations were routinely taken following hospital policy and compared to simultaneous noninvasive determinations of hemoglobin. A preoperative invasive value ≤9 g/dL would have caused cancelation of surgery and implied further investigations. RESULTS: A Bland-Altman plot showed that the average difference between noninvasively obtained hemoglobin and laboratory hemoglobin concentration was -0.44 g/dL (bias) with a standard deviation of the mean bias of 1.04 g/dL. A hemoglobin error grid showed that the noninvasive device could identify almost all invasive hemoglobin values >9 g/dL. In total, there were 4 false-positive values where noninvasively obtained hemoglobin observations were below while the paired invasive values were above 9 g/dL. CONCLUSION: The data in this pediatric setting suggest that the device may eliminate the need for venipuncture in nonanemic children.

The use of a noninvasive hemoglobin monitor for determining fluid distribution and elimination in pediatric patients undergoing minor surgery.

In pediatric fluid therapy it would be preferable to describe distribution and elimination a fluid bolus based on repetitive hemoglobin (Hb) according to kinetic principles. Pulse CO-Oximetry is a recent advancement in patient monitoring that allows for the continuous noninvasive measurement of Hb (SpHb). The aim of this study was to describe the distribution and elimination of hydroxyethylstarch (HES) 130/0.4 in combination with crystalloids using a noninvasive Hb monitor in two cohorts of young children undergoing minor surgeries under general anesthesia. Two cohorts, 16 children aged 1-3 years and 12 aged 4-6 years, were investigated during anesthesia and minor surgical procedures. They were given a maintenance solution of lactated Ringer's and a fluid bolus of HES 130/0.4, 6 mL/kg over a period of 20 min. The whole procedure lasted 120 min, and SpHb values were measured every 10 min. The SpHb values were used to calculate plasma dilution, net volume, and mean residence time (MRT) of the infused fluid. A total of 377 measured SpHbs generated individual dilution plots that showed variability, particularly for the older cohort. Distribution and elimination rates of the infused fluid were calculated. Mean dilution plots were generated. There were no significant differences in dilution, net volume or MRT between groups. A non invasive Hb analyzer could be used to calculate fluid distribution. The variability in the data can probably be explained by reactions to anesthetic drugs, variability in measurement technique, variability in generating the complex capillary signals, and individual variability in baseline fluid status. The latter finding is important because this is a prerequisite for perioperative fluid planning for each individual.

The effect of propofol on intrathecal morphine-induced pruritus and its mechanism.

BACKGROUND: Previous studies have shown that a low dose of propofol IV bolus had a beneficial effect on intrathecal morphine-induced pruritus in humans. However, its exact mechanism has not been fully understood. In this study, we hypothesized that propofol relieved intrathecal morphine-induced pruritus in rats by upregulating the expression of cannabinoid-1 (CB[1]) receptors in anterior cingulate cortex (ACC). METHODS: Twenty-four Sprague-Dawley rats were divided into a control group and 20, 40, 80 µg/kg morphine groups to create an intrathecal morphine-induced scratching model. The effects of propofol on intrathecal 40 µg/kg morphine-induced scratching responses were then evaluated. Sixty rats were randomly assigned to control, normal saline, intralipid, and propofol groups, with pruritus behavior observation or killed 8 minutes after venous injection of normal saline, intralipid, or propofol, and brain tissues were then collected for assay. Immunohistochemistry was then performed to identify the expression of CB (1) receptor in ACC, and the concentration of CB(1) receptor in ACC was determined by Western blot analysis. RESULTS: Compared with the control group, rats in the 20, 40, 80 µg/kg morphine groups had higher mean scratching response rates after intrathecal morphine injection (P =0.020, 0.005, and 0.002, respectively). There was a statistical difference between 20 and 40 µg/kg morphine groups at 10 to 15 and 15 to 20 timepoints after intrathecal morphine injection (P = 0.049 and 0.017, respectively). Propofol almost abolished the scratching response that was induced by 40 µg/kg intrathecal morphine injection (F[2, 15] = 46.87, P < 0.001; F[22, 165] = 2.37, P = 0.001). Compared with the intralipid and normal saline groups, the scratching behavior was significantly attenuated in the propofol group (P < 0.001). Compared with control, normal saline, and intralipid groups, the protein expression of CB(1) receptor in ACC (Western blot) in the propofol group increased (0.86 ± 0.21, 0.94 ± 0.18, 0.86 ± 0.13, and 1.34 ± 0.32, respectively, P < 0.001). There was no significant difference among control, normal saline, and intralipid groups. Compared with the control, normal saline, and intralipid groups, the average number of neurons of CB(1) receptor in the ACC area were higher in the propofol group (21.0 ± 1.4, 19.3 ± 1.8, 24.8 ± 7.7, and 37.2 ± 3.3, respectively, P < 0.001). CONCLUSIONS: Morphine elicits dose-independent scratching responses after intrathecal injection in rats. Morphine 40 µg/kg intrathecal injection-induced scratching responses can be prevented by propofol. Increased protein expression of CB(1) receptors in ACC may contribute to the reversal of intrathecal morphine-induced scratching.

[Effect of single-dose dexmedetomidine on recovery profiles after sevoflurane anesthesia with spontaneous respiration in pediatric patients undergoing cleft lip and palate repair].

OBJECTIVE: To explore the effect of single-dose dexmedetomidine on recovery period after sevoflurane anesthesia with spontaneous respiration in pediatric patients undergoing cleft lip and palate repair. METHODS: A total of 60 American Society of Anesthesiologists (ASA) I-II pediatric patients undergoing cleft lip and palate repair from October to December 2013 were randomly divided into groups D and C (n = 30 each) . Dexmedetomidine 0.5 µg/kg (group D) or an equal volume of normal saline (group C) was ad ministered intravenously over a period of 10 min at 30 min before the end of surgery. Anesthesia was induced and maintained with sevoflurane under spontaneous ventilation. Heart rate, mean arterial pressure (MAP), hemoglobin oxygen saturation (SpO2), respiratory rate, tidal volume (VT) and pressure of end-tidal carbon dioxide (PETCO2) were recorded at the time before induction (T0), 30 min before the end of surgery (T1) , 20 min before the end of surgery (T2), 15 min before the end of surgery (T3), 10 min before the end of surgery (T4), the end of surgery (T5), extubation (T6), 5 min after transferal into post-anesthesia care unit (PACU) (T7) , 1 h after surgery (T8) , extubation time, length of PACU stay, fentanyl consumption and adverse events were all recorded. The incidence and severity of coughing and emergence agitation were assessed. RESULTS: Compared to T0, MAP and heart rate at T1 to T5 all decreased in two groups (P < 0.05). MAP and heart rate at T6 both increased in two groups and group C was higher than group D (P < 0.05). No inter-group differences existed in SpO2, respiratory rate, VT or PETCO2. The incidence of coughing and emergence agitation (30% and 13.3%), fentanyl consumption of group D (0.8 ± 2.1 µg) were all significantly lower than that of group C [(66.7% vs 56.7%) and (4.9 ± 6.50) µg, P < 0.05]. Length of PACU stay in group D was shorter than that in group C [(15 ± 6) vs (23 ± 19) min, P < 0.05]. No inter-group difference existed in extubation time or adverse events. CONCLUSION: A single intravenous dose of dexmedetomidine is effective in reducing emergence agitation and coughing, shortening length of PACU stay and improving the quality of recovery period after sevoflurane anesthesia in pediatric patients undergoing cleft lip and palate repair.