Obstructive Jaundice does not Change the Population Pharmacokinetics of Etomidate in Patients who Underwent Bile Duct Surgery.

BACKGROUND: Etomidate is commonly used in the induction of anesthesia. We have previously confirmed that etomidate requirements are significantly reduced in patients with obstructive jaundice and that etomidate anesthesia during Endoscopic Retrograde Cholangiopancreatography (ERCP) results in more stable hemodynamics compared to propofol. The aim of the present study is to investigate whether obstructive jaundice affects the pharmacokinetics of etomidate in patients who underwent bile duct surgery. METHODS: A total of 18 patients with obstructive jaundice and 12 non-jaundiced patients scheduled for bile duct surgery were enrolled in the study. Etomidate 0.333 mg/kg was administered by IV bolus for anesthetic induction. Arterial blood samples were drawn before, during, and up to 300 minutes after the bolus. Plasma etomidate concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A nonlinear mixed-effects population modeling approach was used to characterize etomidate pharmacokinetics. The covariates of age, gender, height, weight, Body Surface area (BSA), Body Mass Index (BMI), Lean Body Mass (LBM), Total Bilirubin (TBL), Alanine Aminotransferase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), creatinine (CR), and blood urea nitrogen (BUN) were tested for significant effects on parameters using a multiple forward selection approach. Covariate effects were judged based on changes in the Objective Function Value (OFV). RESULTS: A three-compartment disposition model adequately described the pharmacokinetics of etomidate. The model was further improved when height was a covariate of total clearance [Cl1=1.30+0.0232(HT-162), ΔOFV=-7.33; P<0.01)]. The introduction of any other covariates, including bilirubin and total bile acids, did not improve the model significantly (P>0.01). For the height of 162cm, the final pharmacokinetic parameter values were as follows: V1=1.42 (95% CI, 1.01-1.83, L), V2=5.52 (95% CI, 4.07-6.97, L), V3=63.9 (95% CI, 41.95-85.85, L),Cl1= 1.30 (95% CI, 1.19-1.41, L/min), Cl2= 1.21 (95%CI, 0.95-1.47, L/min), and Cl3=0.584 (95%CI, 0.95-1.21, L/min), respectively. CONCLUSION: A 3-compartment open model might best describe the concentration profile of etomidate after bolus infusion for anesthesia induction. The pharmacokinetics of etomidate did not change by the presence of obstructive jaundice.

Preemptive analgesic effectiveness of single dose intravenous ibuprofen in infants undergoing cleft palate repair: a randomized controlled trial.

BACKGROUND: Correction surgery for cleft palate is recommended between 9 and 18 months of age. Patients suffer from acute pain after palatoplasty. Clinicians are hesitant to use opioids for analgesia concerning the potential high risk of respiratory adverse events. Intravenous ibuprofen perhaps be a suitable adjuvant to pain relief. We try to assess whether preoperative administration of intravenous ibuprofen can decrease opioid requirements following cleft palate repair in infants. METHODS: This single center prospective randomized clinical trial was performed from February to April 2021 at Department of Anesthesiology in Shanghai Children's Medical Center. Forty patients ASA I-II, aged 9-24 months with isolated cleft palate and undergoing palatoplasty were randomized in a 1:1 ratio to receive either a single dose of 10 mg/kg ibuprofen intravenously or normal saline at induction. Children and infants postoperative pain scale (CHIPPS) was used for pain assessment. Those patients CHIPPS pain score equal or higher than 4 received analgesic rescue with titrating intravenous fentanyl 0.5 µg/kg and repeated in 10 min if required. The primary outcome was the amount of postoperative fentanyl used for rescue analgesia in postanesthesia care unit (PACU). RESULTS: Patients (n = 20 in each group) in IV-Ibuprofen group required less postoperative fentanyl than those in placebo group (p<0.001). There was no significant difference between two groups in first rescue analgesia time (p = 0.079) and surgical blood loss (p = 0.194). No incidence of obvious adverse events had been found within the first 24 h after surgery in both groups. CONCLUSIONS: Preemptive intravenous administration ibuprofen 10 mg/kg at induction had a significant opioid sparing effect in early postoperative period without obvious adverse effects in infants undergoing palatoplasty. TRIAL REGISTRATION: CHICTR, CTR2100043718, 27/02/2021 http://www.chictr.org.cn/showproj.aspx?proj=122187.

Comparison of the ED50 propofol requirements during the insertion of laryngeal mask airway Ambu AuraFlex with Ambu AuraOnce in children undergoing strabismus surgery.

WHAT IS KNOWN AND OBJECTIVE: Optimal airway management is crucial in strabismus surgery due to the inaccessibility of the airway throughout the procedure. Laryngeal mask airway offers advantages over tracheal intubation in ophthalmic surgery as it does not increase the intraocular pressure. The purpose of this study was to determine the median effective dose of propofol required, when combined with 0.2 µg/kg of sufentanil, for smooth insertion of Ambu AuraFlex in the first attempt in children undergoing strabismus surgery, and to compare it with that for Ambu AuraOnce. METHODS: Forty-three paediatric patients undergoing strabismus surgery under general anaesthesia were recruited. For induction, the initial dosage of propofol was 2 mg/kg in the AuraOnce group or 3 mg/kg in the AuraFlex group. In accordance with Dixon's up-and-down method, the dose of propofol for consecutive patients in each group was adjusted in increments or decrements of 0.25 mg/kg based on the previous patient's "three-point, six-category scale" response to the first attempt of insertion of the randomized device. Insertion of the device was attempted when the bispectral index was ≤60 for 5 s after propofol administration without the use of neuromuscular blocking agents. RESULTS AND DISCUSSION: The median effective dose (95% confidence interval) of propofol was significantly lower in the Ambu AuraOnce group than in the Ambu AuraFlex group (1.92 [1.50-2.32] mg/kg vs. 2.98 [2.49-3.94] mg/kg; p = 0.002). The incidence of dislodgement of the device was significantly higher with the use of the Ambu AuraOnce than with the use of AuraFlex (p = 0.023), whereas insignificant differences were observed between the two groups in the incidence of other perioperative adverse events. WHAT IS NEW AND CONCLUSION: Ambu AuraFlex requires a significantly higher dose of propofol for insertion and provides more effective and stable airway management in strabismus surgery than AuraOnce.

Effect of recorded maternal voice on emergence agitation in children undergoing bilateral ophthalmic surgery: A randomised controlled trial.

AIM: This study was designed to investigate whether the playing-back of the recorded maternal voice through the headphones to children undergoing bilateral ophthalmic surgery has clinical effects on the incidence of emergence agitation, and the anaesthesia recovery course. METHODS: In this prospective, blinded and randomised study, 127 children, aged 2-8 years and undergoing bilateral ophthalmic surgery were randomly allocated to one of the two groups: group T (treatment group, listening to recorded mother's voice via headphones) or group C (control group, wearing headphones without auditory stimuli). The primary outcome was the incidence of emergence agitation, and the secondary outcomes were the awakening time, and the post-anaesthesia care unit (PACU) stay time. RESULTS: Children in the group of listening recorded mother's voice exhibited significantly low incidence of emergence agitation compared with those in the control group (32.8 vs. 55.6%; odds ratio (95% confidence interval): 0.39(0.19-0.80); P = 0.010). The awakening time was shorter in group T as compared to that in group C (22.9 (10.4) vs. 27.3 (13.7); P = 0.048). As results, the group T had significantly less PACU stay time with early discharge than the group C did (29.7 (12.1) vs. 34.8 (14.1); P = 0.031). CONCLUSIONS: Recorded mother's voice is an efficient method to reduce emergence agitation in children undergoing bilateral ophthalmic surgery with sevoflurane anaesthesia. Also, patients woke faster and PACU stay time was shorter in the mother's voice group as compared with the control group.

Dilation of the cystic duct confluence in laparoscopic common bile duct exploration and stone extraction in patients with secondary choledocholithiasis.

BACKGROUND: Many options exist for the management of cholelithiasis and secondary choledocholithiasis. Among them, laparoscopic common bile duct exploration (LCBDE) with choledocotomy followed by laparoscopic cholecystectomy has gained popularity. However, efforts should be made to ensure minimally invasive or noninvasive management of the common bile duct (CBD). The purpose of this study was to explore the clinical experience of non-invasive surgical modality, i.e., laparoscopic transcystic dilation of the cystic duct confluence in CBD exploration (LTD-CBDE), including feasibility, safety, adverse events, and incidence. METHODS: In this retrospective analysis, 68 patients were offered the LTD-CBDE technique from December 2015 to April 2018 based on patient's own intention. During the surgery, the cystic duct confluence was dilated with separation forceps and/or a columnar dilation balloon. Subsequently, CBD exploration and stone extraction were performed with a choledochoscope. The entrance of the CBD was covered with a cystic duct stump wall and was subjected to primary closure at the end of surgery. RESULTS: Forty-nine females and 19 males with cholelithiasis and secondary choledocholithiasis were included. The mean age was 53 years old (18 to 72 year). Of these patients, 62 (91.2%) were successfully treated with the LTD-CBDE technique, and bile leakage was observed in 3 patients (4.4%). The mean operation time was 106 min, and the mean hospital stay was 5.9 days. Among the other 6 patients, 3 were converted to open cholecystectomy due to severe fibrosis, unclear anatomical structure at Calot's triangle (n = 2) or Mirizze syndrome (n = 1); LCBDE was performed in 3 patients due to cystic duct atresia (n = 2) and low level of flow from the gallbladder duct into the CBD (n = 1). These patients had a smooth postoperative course. In total, 43/68 of the patients presented no radiological evidence of retained CBD stones at the postoperative follow-up (40 patients treated with LTD-CBDE) 1 year later. CONCLUSIONS: The current work suggests that LTD-CBDE for the management of cholelithiasis and secondary choledocholithiasis is a feasible, safe and effective technique with a low complication rate. LTD-CBDE offers another alternative for surgeons to treat patients in similar scenarios. However, additional randomized, controlled studies are needed to demonstrate its efficacy, safety, and impact on CBD stenosis.

Population Pharmacokinetic Modeling of Remifentanil in Infants with Unrepaired Tetralogy of Fallot.

BACKGROUND: Although there is literature suggesting that pathophysiologic changes in children with congenital heart disease alter the pharmacokinetics of anesthetics and may result in dosage adjustment, limited information exists regarding the pharmacokinetics of remifentanil in infants with unrepaired tetralogy of Fallot (TOF). The objectives of the current analysis were to characterize the population pharmacokinetics of remifentanil in infants, and to evaluate the effects of TOF on remifentanil's pharmacokinetics. METHODS: Twenty-seven infants (16 with TOF and 11 with normal cardiac anatomy; aged 114-360 days) scheduled to undergo elective surgery under general anesthesia were recruited in the study. All children received remifentanil 1 µg/kg/min intravenously for anesthesia induction and early maintenance [until ~ 20 min before cardiopulmonary bypass (CPB) for patients with TOF]. Serial arterial blood samples were drawn and analyzed. Population pharmacokinetics of remifentanil was characterized using NONMEM software. The estimates were standardized to a 70-kg adult using a per-kilogram model. RESULTS: A two-compartment disposition model adequately described the pharmacokinetics of remifentanil. Besides body weight, the introduction of any other covariates, including TOF status, did not improve the model significantly (P > 0.05). The population parameter estimates for systemic clearance (Cl1) and inter-compartment clearances (Cl2) were 6.03 × (WT/70 kg) and 1.23 × (WT/70 kg) L/min, respectively, and central volume of distribution (V1) and peripheral volumes of distribution (V2) were 19.6 × (WT/70 kg) and 21.7 × (WT/70 kg) L, respectively. CONCLUSIONS: Unrepaired TOF does not change the pharmacokinetics of remifentanil, suggesting a similar dosage for infants with TOF compared to normal cardiac anatomy infants. CLINICAL TRIAL REGISTRATION: The patient enrollment in this study started at 2012, so we do not have clinic trial number, but we still think this is a valuable research and hope it could be considered for publication.

Selection of cuffed endotracheal tube for children with congenital heart disease based on an ultrasound-based linear regression formula.

It remains to be discovered whether a formula predicting the subglottic transverse diameter measured by ultrasound (SGDformula) for the selection of an appropriate endotracheal tube (ETT) for children without congenital heart disease (CHD) is useful for children with CHD. A formula for predicting SGD was established after assessing 60 children ≤ 8 years without CHD and validated on 60 children with CHD. We selected the cuffed ETT size based on the SGD by ultrasound (SGDultra). Subsequently, the fit of the ETT cuff in 60 children with CHD was examined via air-leak test. The maximum allowed difference between the SGDformula and the ETT size that fit was 0.2 mm. The agreement among and accuracy of SGDultra, SGDformula, and the ETT used in children was analyzed. For children without CHD, we adopted a linear formula, given by SGDformula (mm) = 0.4 × age + 5.3. For children with CHD, allometric formula was adopted, given by SGDformula (mm) = 5.4 × age0.18. A stronger agreement exists between SGDultra and ETT size compared to that between SGDformula and ETT size. And the mean bias (SGDformula-ETT size and SGDultra-ETT size) was 0.21 mm (95% confidence interval, - 0.59 to 1.01 mm) and 0.00 mm (- 0.79 to 0.84 mm). For the CHD group, the ultrasound-based method yielded a 78% success rate of ETT size choice, while the formula-based method permitted an appropriate ETT size in only 32% of subjects (P < 0.001). Our analysis showed that measuring the SGDultra was more accurate in predicting the correct OD of the ETT in children with CHD undergoing cardiovascular surgery, based on the correlation and agreement with ETT OD.

The pharmacokinetics of dexmedetomidine in patients with obstructive jaundice: A clinical trial.

OBJECTIVES: Dexmedetomidine, a highly selective central α2-agonist, undergoes mainly biotransformation in the liver. The pharmacokinetics of dexmedetomidine were significantly affected by hepatic insufficiency. The clearance of dexmedetomidine in patients with severe hepatic failure decreased by 50% compared with controls. We tested the hypothesis that the pharmacokinetics of dexmedetomidine would be affected by obstructive jaundice. The prospective registration number of clinical trial is ChiCTR-IPR-15007572. METHODS: 18 patients with obstructive jaundice and 12 non-jaundiced patient controls received dexmedetomidine, 1 µg/kg, over 10 min. Arterial blood samples were drawn before, during, and up to 5 h after the infusion. Plasma dexmedetomidine concentrations were determined by 1290 infinity high performance liquid chromatography coupled with 6470 tandem mass spectrometry. The relevant pharmacokinetic parameters were calculated by non-compartmental analysis using Phoenix WinNonlin 7.0. RESULTS: Plasma clearance of dexmedetomidine was decreased by 33.3% in the obstructive jaundice group as compared with the control group (0.0068±0.0017 vs. 0.0102±0.0033 L/kg/min; P = 0.002). Volume of distribution was decreased by 29.2% in the obstructive jaundice group as compared with the control group (1.43±0.58 vs. 2.02±0.84 L/kg; P = 0.041). CONCLUSIONS: This study demonstrates that the clearance and distribution volume of dexmedetomidine were decreased in patients with obstructive jaundice. It may be advisable to adjust the dose of dexmedetomidine in those patients.

Differential Inhibition of Nav1.7 and Neuropathic Pain by Hybridoma-Produced and Recombinant Monoclonal Antibodies that Target Nav1.7 : Differential activities of Nav1.7-targeting monoclonal antibodies.

The voltage-gated Na+ channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na+ currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na+ currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na+ currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.

The prediction probabilities for emergence from sevoflurane anesthesia in children: A comparison of the perfusion index and the bispectral index.

BACKGROUND: Predicting recovery of consciousness is one of the most essential functions of anesthesia depth monitors in anesthesia practice. Perfusion index and bispectral index are 2 indicators of the anesthesia depth monitoring with different working principles. The progression of the anesthesia emergence stages reflected by those monitors has not been well understood, especially in pediatric patients. The goals of this study were to compare the prediction probabilities of perfusion index and bispectral index in predicting awakening and in differentiating the different levels of arousal during emergence after sevoflurane anesthesia in children undergoing open inguinal hernia repairs. METHODS: Forty-five patients, aged 1 to 5 years, ASA Status I or II and scheduled for elective open inguinal hernia repairs under general anesthesia were enrolled. The perfusion index and bispectral index were monitored simultaneously during anesthesia recovery. The University of Michigan Sedation Scale was applied to evaluate the clinical arousal levels during emergence. The prediction probability was used to assess the performance of perfusion index and bispectral index in predicting awakening and distinguishing different levels of arousal corresponding to the University of Michigan Sedation Scale during recovery. RESULTS: The prediction probability of perfusion index (PkPI-Awakening  = .81, 95% CI 0.73-0.89) in differentiating full consciousness from unconsciousness during recovery was comparable to that of bispectral index (PkBIS- Awakening  = .86, 95% CI 0.79-0.92) (P = .47). The prediction probability for perfusion index (PkPI-UMSS  = .61, 95% CI 0.55-0.73) and bispectral index (PkBIS-UMSS  = .64, 95% CI 0.53-0.69) had similar performance in distinguishing different University of Michigan Sedation Scale levels. CONCLUSION: Both the perfusion index and bispectral index performed comparably well in predicting awakening and different arousal levels when emerging from sevoflurane anesthesia in children.

Cyclic stretch induced IL-33 production through HMGB1/TLR-4 signaling pathway in murine respiratory epithelial cells.

Interleukin 33 (IL-33), an inflammatory and mechanically responsive cytokine, is an important component of a TLR4-dependent innate immune process in mucosal epithelium. Although TLR4 also plays a role in sensing biomechanical stretch, a pathway of stretch-induced TLR4-dependent IL-33 biosynthesis has not been revealed. In the current study, we show that short term (6 h) cyclic stretch (CS) of cultured murine respiratory epithelial cells (MLE-12) increased intracellular IL-33 expression in a TLR4 dependent fashion. There was no detectable IL-33 in conditioned media in this interval. CS, however, increased release of the notable alarmin, HMGB1, and a neutralizing antibody (2G7) to HMGB1 completely abolished the CS mediated increase in IL-33. rHMGB1 increased IL-33 synthesis and this was partially abrogated by silencing TLR4 suggesting additional receptors for HMGB1 are involved in its regulation of IL-33. Collectively, these data reveal a HMGB1/TLR4/IL-33 pathway in the response of respiratory epithelium to mechanical stretch.

Dezocine exhibits antihypersensitivity activities in neuropathy through spinal µ-opioid receptor activation and norepinephrine reuptake inhibition.

Dezocine is the number one opioid painkiller prescribed and sold in China, occupying 44% of the nation's opioid analgesics market today and far ahead of the gold-standard morphine. We discovered the mechanisms underlying dezocine antihypersensitivity activity and assessed their implications to antihypersensitivity tolerance. Dezocine, given subcutaneously in spinal nerve-ligated neuropathic rats, time- and dose-dependently produced mechanical antiallodynia and thermal antihyperalgesia, significantly increased ipsilateral spinal norepinephrine and serotonin levels, and induced less antiallodynic tolerance than morphine. Its mechanical antiallodynia was partially (40% or 60%) and completely (100%) attenuated by spinal µ-opioid receptor (MOR) antagonism or norepinephrine depletion/α2-adrenoceptor antagonism and combined antagonism of MORs and α2-adenoceptors, respectively. In contrast, antagonism of spinal κ-opioid receptors (KORs) and δ-opioid receptors (DORs) or depletion of spinal serotonin did not significantly alter dezocine antiallodynia. In addition, dezocine-delayed antiallodynic tolerance was accelerated by spinal norepinephrine depletion/α2-adenoceptor antagonism. Thus dezocine produces antihypersensitivity activity through spinal MOR activation and norepinephrine reuptake inhibition (NRI), but apparently not through spinal KOR and DOR activation, serotonin reuptake inhibition or other mechanisms. Our findings reclassify dezocine as the first analgesic of the recently proposed MOR-NRI, and reveal its potential as an alternative to as well as concurrent use with morphine in treating pain.

The agreement between oscillometric and intra-arterial technique for blood pressure monitoring in the lower extremities for infants and toddlers undergoing aortic coarctation repair.

OBJECTIVE: Anesthetic management for patients undergoing surgical repair of aortic coarctation (CoA) should include constant blood pressure monitoring of the right upper extremity and a lower extremity. The delayed or absent pulse in the lower limbs often leads to unsuccessful arterial cannulation in infants and the oscillometric technique used for blood pressure measurement. The aim of this study was to evaluate the agreement between the oscillometric method and intra-arterial technique for blood pressure monitoring in the lower limbs of infants undergoing CoA. METHODS: A total of 45 infants diagnosed with isolated CoA were initially enrolled in this study and five were excluded because of cannulation failure. Thus, 40 patients had their blood pressure measured simultaneously by both oscillometric technique on the thigh and femoral artery catheterization. After induction and intubation, five pairs of blood pressure readings from each patient were collected in an interval of 3 min. Statistical analysis was accomplished by revised Bland-Altman analysis. RESULTS: There was a strong correlation between oscillometric and invasive blood pressure measurements [systolic blood pressure (SBP) r = 0.771, diastolic blood pressure (DBP) r = 0.704 and mean artery pressure (MAP) r = 0.850]. The mean difference and 95% limits of agreement (95% LOA) between oscillometric and femoral artery blood pressure readings was 3.830 mmHg (-19.297, 26.957) for SBP, -8.725 mmHg (-26.236, 8.786) for DBP, and -3.235 mmHg (-18.842, 12.372) for MAP. There were only one pair of MAP (1/40) and two pairs of SBP readings (2/40) out of range (95% LOA), and all of paired DBP readings were within 95% LOA. CONCLUSION: There was a good agreement between oscillometric and invasive blood pressure measurements of lower extremities in infants with isolated CoA statistically. However, the oscillometry-measured SBP showed a tendency to overestimate the intra-arterial blood pressure reference, while oscillometry-measured DBP underestimated its reference. MAP measurement provided the most accurate and reliable results in this study.

Unrepaired Tetralogy of Fallot-related Pathophysiologic Changes Reduce Systemic Clearance of Etomidate in Children.

BACKGROUND: Pathophysiologic changes in children with congenital heart disease may alter the effect of drugs by influencing the pharmacokinetics (PK). Considering the limited literature that describes the PK of etomidate in pediatric patients, especially in those with tetralogy of Fallot (TOF), our aim was to characterize the PK of etomidate and explore the effects of TOF. METHODS: Twenty-nine pediatric patients (15 with TOF and 14 with normal cardiac anatomy) scheduled to undergo elective surgery under general anesthesia were recruited in the study. All children received etomidate 60 µg/kg/min intravenously until a bispectral index of ≤50 was reached for 5 seconds during anesthesia induction. Arterial blood samples were drawn and analyzed. Population analysis was performed by using NONMEM to define PK characteristics. The estimates were standardized to a 70-kg adult using a per-kilogram model. RESULTS: Data consisting of 244 samples from 29 children with a mean age of 236 days (range, 86-360 days) were used, including a TOF group with a mean age of 250 days (range, 165-360 days) and a normal cardiac anatomy group with a mean age of 221 days (range, 86-360 days). A 3-compartment disposition model was best fitted to describe the PK of etomidate. The introduction of TOF as a covariate for systemic clearance (Cl1) improved the model and resulted in a significant reduction of objective function (Δobjective function = -7.33; P = .0068), which means that TOF was a significant covariate of Cl1, and the etomidate Cl1 in children with TOF (1.67 × (weight [WT]/70 kg) L/min) was lower than those with normal cardiac anatomy (2.28 × (WT/70 kg) L/min). Other PK parameter values were as follows: V1 = 8.05 × (WT/70 kg) L; V2 = 13.7 × (WT/70 kg) L; V3 = 41.3 × (WT/70 kg) L; Cl2 = 3.35 × (WT/70 kg) L/min; Cl3 = 0.563 × (WT/70 kg) L/min. CONCLUSIONS: A decreased systemic clearance for etomidate in children with TOF resulted in a lower required infusion rate and variation with time to achieve the same plasma concentration and maintain an equivalent target concentration or have longer sedation and recovery times after bolus or continuous infusion than normal children.

IL-33 Signaling in Lung Injury.

Interleukin (IL)-33, a member of the IL-1 cytokine super-family, acts as both a traditional cytokine and an intracellular nuclear factor. It is generally released from damaged immune cells and signals through its receptor ST2 in an autocrine and paracrine fashion, plays important roles in type-2 innate immunity, and functions as an "alarmin" or a danger signal for cellular damage or cellular stress. Here, we review recent advances of the role of IL-33 in lung injury and explore its potential significance as an attractive therapeutic target.

Post-Exposure Exercise Fails to Ameliorate Memory Impairment Induced by Propofol and Ketamine in Developing Rats.

BACKGROUND: This aim of this study was to determine the effects of ketamine-propofol combination on learning and memory, as well as exercise, on anesthetic neurotoxicity. MATERIAL/METHODS: A ketamine-propofol combination was administered once (group SKP, Single Ketamine Propofol) on P7 (postnatal day 7) or in 3 treatments on P6, P8, and P10 (group MKP, Multiple Ketamine Propofol). Rat pups in group C (Control) received equivalent volumes of normal saline in 3 injections on P6, P8, and P10. Rats designated MKPR (Multiple Ketamine Propofol and running) and CR (Control and running) began running exercise on P21 on wheels. Learning and memory was assessed by Morris water maze and fear conditioning tests. Hippocampal neurogenesis of rats was detected by BrdU immunofluorescence. RESULTS: MKP rats had longer latency to platform than group C during training in the Morris water maze; SKP rats stayed in the target quadrant longer than MKP rats during testing (P<0.05). Rats in running groups had shorter latency than non-running rats, but running had no interaction with anesthesia exposure. CONCLUSIONS: Repeat ketamine-propofol combination doses increase risk of memory impairment in developing rats. Running has no impact on anesthetic neurotoxicity.

Comparison of dexmedetomidine and chloral hydrate sedation for transthoracic echocardiography in infants and toddlers: a randomized clinical trial.

BACKGROUND: Procedural sedation using chloral hydrate is used in many institutions to improve the quality of transthoracic echocardiograms (TTE) in infants and young children. Chloral hydrate has limited availability in some countries, creating the need for alternative effective sedatives. OBJECTIVE: The aim of our study was to compare the effectiveness of two doses of intranasal dexmedetomidine vs oral chloral hydrate sedation for transthoracic echocardiography. METHODS: This is a randomized, prospective study of 150 children under the age of 3 years with known or suspected congenital heart disease scheduled for transthoracic echocardiography with sedation. Group CH received oral chloral hydrate 70 mg · kg(-1), group DEX2 received 2 µg · kg(-1) intranasal dexmedetomidine, and group DEX3 received 3 µg · kg(-1) intranasal dexmedetomidine. Acceptance of drug administration, sedation onset and duration, heart rate, and oxygen saturation, sonographer and parent satisfaction were recorded. RESULTS: All patients were successfully sedated for TTE. A second sedative dose (rescue) for failed single-dose sedation was required for 4% of patients after CH, none of the patients after DEX2, and 4% of patients after DEX3. Patients in group CH had an average heart rate decline of 22% during sedation, while group DEX2 decreased 27%, and group DEX3 23% (P = 0.2180). Mean time from administration of the sedative to final patient discharge was 96 min after CH, 83 min after DEX2, and 94 min after DEX3 (P = 0.1826). CONCLUSION: Intranasal dexmedetomidine 2 and 3 µg · kg(-1) were found to be as effective for TTE sedation as oral chloral hydrate with similar sedation onset and recovery time and heart rate changes in this study population.

Noninvasive cardiac output monitoring using bioreactance-based technique in pediatric patients with or without ventricular septal defect during anesthesia: in comparison with echocardiography.

BACKGROUND: We evaluated the use of bioreactance-based noninvasive cardiac output (CO) monitoring technique (NICOM(™), CO(NICOM)) in pediatric patients with or without ventricular septal defect (VSD) during anesthesia induction to determine its agreement with the measurements assessed by echocardiography (echo, CO(ECHO)). METHODS: Twenty-eight pediatric patients with normal heart anatomy (group NHA) and 32 with isolated ventricular septal defects (group VSD) were included in this study. The cardiac output was measured simultaneously in minute-by-minute using NICOM and echo (Simpson's rule) during anesthesia induction and intubation. Linear regression and revised Bland-Altman analyses were performed to evaluate the agreement by comparing the paired CO results. The mean percent error ((CO(ECHO)-CO(NICOM))/CO(ECHO) × 100%) was used to assess the impact of congenital heart disease on the agreement. RESULTS: The measurements of CO by NICOM and echo techniques were highly correlated in group NHA (γ = 0.96, P < 0.005) and VSD (γ = 0.84, P < 0.005). The mean bias (CO(ECHO) - CO(NICOM)) between the two methods was 0.03 and 0.31 l·min(-1) with the limits of agreement (LOA) -0.29 to +0.35 l·min(-1) and -0.44 to +1.05 l·min(-1), which include 96.9% (31/32) and 89.3% (25/28) of all patients' different data in group NHA and VSD, respectively. The median percent errors were significantly lower at all time points in group NHA than those in group VSD (all P < 0.05). CONCLUSION: In children without heart defects, the CO measured by NICOM shows a good agreement with the echo during anesthesia induction. The NICOM technique underestimates echo although a strong correlation exists between two methods in children with ventricular septal defect.

The sedative effects and the attenuation of cardiovascular and arousal responses during anesthesia induction and intubation in pediatric patients: a randomized comparison between two different doses of preoperative intranasal dexmedetomidine.

OBJECTIVE: Premedication with intranasal dexmedetomidine (DEX) has shown to be an effective sedative in pediatric patients. This prospective, randomized, and controlled investigation was designed to evaluate whether the difference in intranasal DEX dosing would produce different beneficial effects on the attenuation of cardiovascular and arousal responses during anesthesia induction and intubation. METHODS: Forty children, aged from 3 to 6 years, of American Society of Anesthesiologists physical status I or II and scheduled for elective adenotonsillectomy randomly received intranasal DEX 1 µg·kg(-1) (group D1) or 2 µg·kg(-1) (group D2) 30 min before anesthesia induction. Anesthesia was induced with sevoflurane in oxygen flow. Mean arterial pressure (MAP) and heart rate (HR) as measurements of cardiovascular response and bispectral index (BIS) as an index of arousal response were recorded every 5 min after intranasal DEX administration and measured every 1 min for 5 min after intubation. Sedation status, behavior scores, and mask induction scores were also assessed. RESULTS: Mean arterial pressure did not show statistical differences during the anesthesia induction, but did demonstrate significantly milder responses to laryngoscopy and intubation in group D2 compared with group D1. Change in HR was consistent with MAP during laryngoscopy and intubation. Patients who received 2 µg·kg(-1) DEX presented with deeper sedation and less anxiety by the assessments of the alertness scale, behavior score, and BIS scores. Group D2 dosing achieved more favorable scores in children undergoing mask induction. CONCLUSION: Intranasal DEX 2 µg·kg(-1) administered 30 min before anesthesia induction provides considerable effect to attenuate the increase in MAP caused by intubation response. Changes in HR and BIS also demonstrate that this kind of premedication provides effective attenuation of intubation response. And preoperative intranasal DEX 2 µg·kg(-1) produces optimal-sedation, more favorable anesthesia induction course in pediatric patients. Premedication of intranasal DEX is a considerable way to blunt cardiovascular and arousal responses to endotracheal intubation.