Background: Endovascular embolization was successfully used in treatment of brain arteriovenous malformations (bAVM), respectively or in combination with surgical resection. Deliberate employment of post-operative hypotension was widely recommended by neurosurgeons. Researches on predictors of difficulties in deliberate postoperative hypotension remain scarce. This study aimed to analyze the potential risk factors of difficult cases of deliberate post-operative hypotension. Methods: We retrospectively reviewed all patients who received bAVM embolization between January 2010 and December 2015. Demographic features, clinical presentation, AVM characteristics, peri-operative medication, hemodynamic features, treatment-related information and outcome-related data were recorded. Univariate analysis and logistic regression were performed to find out associated risk factors. Results: Difficulty in deliberate postoperative hypotension was observed in 75 patients the first postoperative day. Logistic regression indicated that higher Sptzler-Martin (S-M) grade was an independent risk factor of difficult deliberate postoperative hypotension following embolization (OR=2.058; 95% CI, 1.364-3.105; P=0.001). While infra-operative dexmedetomidinc administration was a potential independent protective factor (OR=0.356; 95% CI, 0.133-0.956; P=0.040). Conclusions: Higher S-M grade was an independent risk factor of difficult cases of deliberate postoperative hypotension after endovascular embolization, while intra-operative dexmedetomidine administration was potential protective predictor.

Background: Dexmedetomidine (DEX) has been administered to patients during neurosurgery. Some studies have found that DEX could reduce perioperative opioid consumption and postoperative pain intensity. However, no firm conclusions have been reached. The purpose of this meta-analysis was to assess the efficacy of DEX for managing pain in neurosurgical patients. Materials and Methods: A comprehensive literature review was conducted to identify randomized controlled trials (RCTs) focusing on the effects of DEX on perioperative opioid consumption and postoperative pain intensity in patients undergoing neurosurgery. PubMed, the Web of science, the Cochrane Library, and Scopus were searched. The resulting data were combined to calculate the pooled mean differences (MDs), standard MDs or odds ratios (ORs), and 95% confidence intervals (CIs), as appropriate. Heterogeneity and potential publication bias were assessed. Furthermore, a trial sequential analysis was performed to improve the precision of our findings. Results: A total of 11 published RCTs involving 674 patients undergoing neurosurgery (335 patients, 339 controls) were included in this meta-analysis. There were significant differences in postanesthesia care unit (PACU) visual analog scale scores between the groups (MD=−1.54, 95% CI, −2.33 to 0.75, I 2 =87%, P =0.0001). In addition, there were significant differences in PACU opioid requirements between the treatment and control groups (standard MD=−0.88, 95% CI, −1.74 to 0.02, I 2 =91%, P =0.05). Furthermore, intraoperative opioid consumption was significantly reduced in the treatment group (MD=−127.75, 95% CI, −208.62 to 46.89, I 2 =98%, P =0.002). Conclusions: DEX could reduce perioperative and PACU opioid consumption as well as postoperative pain intensity.

In the recent article by Bohl et al [[1]Bohl D.D. Saltzman B.M. Sershon R.A. Darrith B. Okroj K.T. Della Valle C.J. Incidence, risk factors, and clinical implications of pneumonia following total hip and knee arthroplasty.J Arthroplasty. 2017; 32: 1991-1995.e1Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar] assessing the incidence, risk factors, and clinical implications of postoperative pneumonia in 171,200 patients undergoing total hip and knee arthroplasties, the multivariate analysis showed that diabetes mellitus, chronic obstructive pulmonary disease, dependent functional status, greater age (most notably ≥80 years), dyspnea on exertion, hypertension, lower body mass index, current smoker status, and male sex were the independent risk factors for postoperative pneumonia. The power of this study is its use of a large database from the American College of Surgeons National Surgical Quality Improvement Program, which includes most of known preoperative and intraoperative risk factors affecting postoperative complications and mortality of surgical patients. Moreover, the right statistical methods were used to identify the risk factors of postoperative pneumonia. However, we noted that several issues of this study were not well addressed. First, only anemia, functional status, the presence/absence of diabetes, dyspnea on exertion, hypertension, and chronic obstructive pulmonary disease were collected as preoperative comorbidities and used as confounding factors for statistical adjustment. This seems inability to provide overall comorbidity burden of patients at the time of surgery. The available evidence indicates that congestive heart failure, liver disease, chronic renal disease, and respiratory infection in the last month are the independent risk factors of postoperative pulmonary complications [[2]Canet J. Gallart L. Predicting postoperative pulmonary complications in the general population.Curr Opin Anaesthesiol. 2013; 26: 107-115Crossref PubMed Scopus (56) Google Scholar]. In fact, overall comorbidity burden of surgical patients at the time of surgery can be measured by the Charlson comorbidity index. Furthermore, the recent work shows that the preoperative overall comorbidity burden evaluated by the Charlson comorbidity index is a significant risk factor of pneumonia after total hip arthroplasty [[3]Glassou E.N. Hansen T.B. Pedersen A.B. Risk of pneumonia and urinary tract infection within the first week after total hip arthroplasty and the impact on survival.Clin Epidemiol. 2017; 9: 31-39Crossref PubMed Scopus (9) Google Scholar]. Second, the preoperative serum albumin levels were not included in demographic data of patients, although hypoalbuminemia (serum albumin <3.5 mg/dL) has been associated significantly with the development of pneumonia after total knee arthroplasty [[4]Kamath A.F. Nelson C.L. Elkassabany N. Guo Z. Liu J. Low albumin is a risk factor for complications after revision total knee arthroplasty.J Knee Surg. 2017; 30: 269-275PubMed Google Scholar]. The guideline of the American College of Physicians on risk assessment for and strategies to reduce perioperative pulmonary complications for patients undergoing noncardiothoracic surgery recommends that in all patients with a clinically suspected hypoalbuminemia and in those with one or more risk factors of postoperative pulmonary complications, serum albumin levels should be measured [[5]Qaseem A. Snow V. Fitterman N. hornbake E.R. Lawrence V.A. Smetana G.W. et al.Clinical Efficacy Assessment Subcommittee of the American College of Physicians: risk assessment for and strategies to reduce perioperative pulmonary complications for patients undergoing noncardiothoracic surgery: a guideline from the American College of Physicians.Ann Intern Med. 2006; 144: 575-580Crossref PubMed Scopus (497) Google Scholar]. Third, this study did not provide perioperative blood transfusion, despite it is frequently used in total hip and knee arthroplasties. In the available literature, perioperative blood transfusion has been significantly associated with increased risk of pneumonia after total hip arthroplasty [[6]Pedersen A.B. Mehnert F. Overgaard S. Johnsen S.P. Allogeneic blood transfusion and prognosis following total hip replacement: a population-based follow up study.BMC Musculoskelet Disord. 2009; 10: 167Crossref PubMed Scopus (95) Google Scholar]. Thus, we argue that in this study, not taking above risk factors into the model would have tampered with the inferences of multivariate analysis for risk factors of pneumonia after total hip and knee arthroplasties. Conflict of Interest Statement for XueView Large Image Figure ViewerDownload Hi-res image Download (PPT)Conflict of Interest Statement for YangView Large Image Figure ViewerDownload Hi-res image Download (PPT)Conflict of Interest Statement for Ya-Yang LiuView Large Image Figure ViewerDownload Hi-res image Download (PPT) Incidence, Risk Factors, and Clinical Implications of Pneumonia Following Total Hip and Knee ArthroplastyThe Journal of ArthroplastyVol. 32Issue 6PreviewThe purpose of this study is to determine the incidence, risk factors, and clinical implications of pneumonia following total joint arthroplasty (TJA). Full-Text PDF Response to Letter to the Editor on “Incidence, Risk Factors, and Clinical Implications of Pneumonia Following Total Hip and Knee Arthroplasty”The Journal of ArthroplastyVol. 33Issue 6PreviewWe would like to thank Liu et al for commenting on our manuscript entitled “Incidence, risk factors, and clinical implications of pneumonia following total hip and knee arthroplasty.” [1] This manuscript used the National Surgical Quality Improvement Program (NSQIP) to identify patients at greatest risk for developing pneumonia postoperatively. The authors had several thoughtful critiques of the manuscript's methods. Full-Text PDF

demographic and surgical variables were comparable between the two series.Furthermore, the small sample size of this study may not exclude a high risk of α statistical error.Because of these limitations, it is difficult to differentiate whether the improved renal function parameters obtained in this study are attributable to the natural recovery process of AKI or the efficiency of fenoldopam.To address this issue, multicentre randomized controlled trials with a large sample size are still needed. Compliance with ethical standards

2010 to October 2010. The clinical history mentioned on the request card was noted and confirmed through ED notes on all patients undergoing CT head scan. Patients presenting with acute sudden onset headache with or without associated clinical symptoms were included. Patients who had acute head trauma, those who had chronic confusion and those who did not have headache were excluded. All scans were double reported by a trainee and a qualified FRCR radiologist. Intracranial haemorrhage, mass and abscess on CT scan were taken as positive findings.

1. Heme oxygenase 1 (HO-1) has been shown to play a pivotal role in the maintenance of cellular homeostasis when the liver undergoes sublethal stress, such as ischaemia-reperfusion (I/R) injury. In the present study, we investigated the protective role of HO-1 in hyperbaric oxygen (HBO) preconditioning against liver injury after I/R. 2. A total hepatic ischaemia (30 min) and reperfusion (60 min) injury model in rats was used in the present study. Preconditioned groups were exposed to HBO 24 h prior to the induction of I/R injury. Other groups were injected with zinc protoporphyrin IX (ZnPP) intraperitoneally 1 h before I/R to inhibit HO-1 activity. At the end of the reperfusion period, blood and liver samples were collected for the analysis of liver injury markers, morphological changes, and HO-1 expression and activity in the liver. 3. In untreated rats, I/R induced an increase in hepatic injury markers, such as plasma transaminases, inflammatory cytokines (tumour necrosis factor-α and interleukin-1β), and tissue malondialdehyde. However, HBO preconditioning attenuated the I/R-induced increases in these hepatic injury markers, and prevented both the necrosis and apoptosis of hepatocytes induced by I/R injury. Furthermore, HBO preconditioning significantly increased HO-1 mRNA and protein levels in the liver. In rats in which HO-1 activity had been inhibited with ZnPP pretreatment, the protective effects of HBO preconditioning against I/R injury were abolished. 4. In conclusion, HBO preconditioning can protect the liver against I/R injury and it appears that this effect might be mediated by the induction of HO-1.

Background and objective The present randomized controlled study was designed to compare the efficacy of remifentanil 2 μg kg−1 and sufentanil 0.2 μg kg−1 by bolus injection on the cardiovascular response to intubation in healthy children. Methods One hundred and five children, ASA 1–2 and scheduled for elective plastic surgery under general anaesthesia, were randomly divided into one of two study groups to receive the following treatments in a double-blind manner: remifentanil 2 μg kg−1 (group R) and sufentanil 0.2 μg kg−1 (group S). Blood pressure and heart rate (HR) were recorded before anaesthesia induction (baseline values), immediately before intubation (postinduction values), at intubation and every minute for 5 min after intubation. The percentage changes in systolic blood pressure (SBP) and HR relative to baseline values were calculated. The incidences of SBP and HR percentage changes of more than 30% of baseline values during the observation were recorded. Results As compared with baseline values, blood pressure and HR at intubation and their maximum values during the observation increased significantly in group S, but decreased significantly in group R. Blood pressure and HR at intubation and their maximum values during the observation were significantly different between the groups. There were significant differences between the groups in the percentage changes of SBP and HR relative to baseline values and their maximum percentage changes during the observation. The incidences of SBP and HR percentage increases of more than 30% of baseline values were not significantly different between the groups, but the incidences of SBP and HR percentage decreases of more than 30% of baseline values were significantly higher in group R than in group S. Conclusion In combination with propofol for anaesthesia induction in children, sufentanil 0.2 μg kg−1 by bolus injection fails to depress the cardiovascular intubation response. Remifentanil 2 μg kg−1 by bolus injection can completely abolish the cardiovascular intubation response, but causes more adverse cardiovascular depression.

BACKGROUND:The authors found no study to compare the efficacy of bolus dose fentanyl and remifentanil blunting the cardiovascular intubation response in children, so they designed this randomized, double-blind clinical study to assess the effects of remifentanil 2 microg/kg and fentanyl 2 microg/kg by bolus injection on the cardiovascular intubation response in healthy children.METHODS:One hundred and two children, the American Society of Anesthesiologists (ASA) physical status 1-2 and scheduled for elective plastic surgery under general anesthesia, were randomly divided into one of two groups to receive the following treatments in a double blind manner: remifentanil 2 microg/kg (Group R) and fentanyl 2 microg/kg (Group F) when anesthesia was induced with propofol and vecuronium. The orotracheal intubation was performed using a direct laryngoscope. Blood pressure (BP) and heart rate (HR) were recorded before anesthesia induction (baseline values), immediately before intubation, at intubation and every minute for 5 minutes after intubation. The percent changes of systolic blood pressure (SBP) and HR relative to baseline values and the rate pressure product (RPP) at every observing point were calculated. The incidences of SBP and HR percent changes >30% of baseline values and RPP >22,000 during the observation were recorded.RESULTS:There were no significant differences between groups in the demographic data, baseline values of BP and HR and the intubation time. As compared to baseline values, BP, HR and RPP at intubation and their maximum values during observation increased significantly in Group F, but they all decreased significantly in Group R. BP, HR and RPP at all observed points, and their maximum values during the observation, were significantly different between groups. There were also significant differences between groups in the percent change of SBP and HR relative to baseline values at all observed points and their maximum percent changes during the observation. The incidences of SBP and HR percent increased >30% of the baseline values and RPP >22,000 during the observation, were significantly higher in Group F than in Group R, but the incidences of SBP and HR percent decreased >30% of baseline values were significantly lower in Group F compared with Group R.CONCLUSIONS:When used as part of routine anesthesia induction with propofol and vecuronium in children, fentanyl 2 microg/kg by bolus injection fails to effectively depress the cardiovascular intubation response. Remifentanil 2 microg/kg by bolus injection can completely abolish the cardiovascular intubation response, but also cause more adverse complications of temporary significant cardiovascular depression.

Summary Midazolam is a common fast‐acting GABAA receptor agonist. Recent data suggest that exposure to midazolam in early life may cause long‐term effects on brain function through stable epigenetic reprogramming. The aim of the present study was to determine whether the administration of midazolam to infant mice would affect their learning and memory in adulthood. An open‐field test was conducted before and then 3, 24, 48 and 72 h after administration of midazolam (50 mg/kg, i.p.) to infant mice. Saline control mice received an equal volume of saline i.p. 3 h before the open‐field test. Total movements, total movement time, total movement distance and velocity were analysed. Novel object recognition (NOR), Morris water‐maze and passive avoidance tests were performed when the treated mice grew to adulthood (105 days of age). The results of open‐field test showed that midazolam significantly reduced locomotor activity (total movements, total movement time, total movement distance and velocity) in infant mice 3 and 24 h after drug administration and that these effects had disappeared by 72 h after drug administration. The results of the water‐maze, NOR and passive avoidance tests in adulthood (at 105 days of age) indicated that administration of midazolam in infancy had no long‐term effects on the learning and memory behaviours of adult mice compared with the saline control. Acute midazolam administration to infant mice affected spontaneous locomotor activity for approximately 2 days, but did not seem to have any significant impact on cognitive functioning that lasted into adulthood.

BACKGROUND:Although there have been numerous favorable reports on the uses of the GlideScope videolaryngoscope (GSVL) in oral and nasal intubations, no study has compared the hemodynamic responses to oral and nasal intubations with the GSVL in a single clinical trial. The purpose of this randomized clinical study was to determine whether there was a clinically relevant difference between the hemodynamic responses to oral and nasal intubations with the GSVL.METHODS:A total of 71 patients, ASA physical status I, aged 18-50 years, scheduled for elective plastic surgery under general anesthesia, were randomly allocated to the oral intubation group (OI group) and the nasal intubation group (NI group). Noninvasive blood pressure (BP) and heart rate (HR) were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation and every minute for a further 5 minutes. Maximum values of BP and HR during the observation were noted. The product of HR and systolic blood pressure (rate pressure product, RPP), the percent changes of systolic blood pressure (SBP) and HR relative to the baseline values at every measuring point, and the areas under the SBP and HR versus time curves were calculated.RESULTS:The intubation time was significantly longer in the NI group than in the OI group. The total incidence of difficulties encountered during laryngoscopy and intubation were higher in the OI group than in the NI group (29% vs. 6%, p < 0.05). BP at all measuring points, the maximum values of BP, the area under the SBP versus time curve, and the incidence of SBP percent increase more than 30% of baseline value did not differ significantly between the two groups. However, HR and RPP at intubation and their maximum values during the observation, the area under the HR versus time curve, and the incidence of HR percent increase more than 30% of baseline value were significantly higher in the OI group than in the NI group (p < 0.05). As compared with the NI group, the times required to reach the maximum values of SBP and HR were significantly shorter and the times required for recovery of SBP and HR to postinduction values were significantly longer in the OI group (p < 0.05).CONCLUSION:In anesthetized adult patients, oral and nasal intubations with the GSVL can result in a similar pressor response. However, the tachycardic response to nasal intubation using a GSVL is smaller and of shorter duration than that to oral intubation using a GSVL.

ObjectiveTo compare the effects of equipotent small-dose remifentanil and fentanyl on hemodynamic response to orotracheal intubation in children.MethodsOne hundred children,American Society of Anesthesiologists(ASA) physical status Ⅰ or Ⅱ and scheduled for elective plastic surgery under general anesthesia,were randomly divided into 2 groups to receive the following treatments in a double blind manner:remifentanil 2 μg/kg(group R) or fentanyl 2 μg/kg(group F)(50 cases each group)when anesthesia was induced with propofol.The orotracheal intubation was performed by the direct laryngoscope.Blood pressure(BP) and heart rate(HR) were recorded before anesthesia induction(baseline values),immediately before intubation,on intubation each minute for 5 minutes after intubation.Percent changes of systolic blood pressure(SBP) and HR relative to baseline values at each observing point were calculated.The rate pressure product(RPP) at each time point was also calculated.ResultsThere were no significant differences between 2 groups in demographic data,baseline values of BP and HR and the intubation time.In group F,tracheal intubation caused significant increases in BP,HR and RPP compared with baseline values.In group R,BP,HR and RPP on intubation and their maximum values during the observation decreased significantly compared with baseline values.BP,HR and RPP at all observing points and their maximum values during the observation were significantly different between 2 groups.There were also significant differences between 2 groups in the percent changes of SBP and HR relative to baseline values at all observing points and their maximum percent changes during the observation.The incidences of SBP and HR percent increases 30% of baseline values were significantly higher in group F than those in group R,but the incidences of SBP and HR percent decreases 30% of baseline values were significantly higher in group R compared with group F.ConclusionsWhen anesthesia was induced with propofol in children,co-adminiatration of equipotent small-dose remifentanil is more effective in attenuating the hemodynamic responses to orotracheal intubation than co-adminiatration of equipotent small-dose fentanyl.Fentanyl 2 μg/kg fails to completely depress the hemodynamic response to orotracheal intubation in children.Remifentanil 2 μg/kg can completely abolish the hemodynamics response to orotracheal intubation,but may cause more adverse cardiovascular depression.

BACKGROUND Because patients with scar contracture of the neck are at a high risk of loss of the airway control after anesthesia induction, awake intubation is usually recommended. This retrospective clinical study was designed to evaluate the possibility, safety and efficacy of airway management and tracheal intubation under general anesthesia in such patients. METHODS This retrospective study included 1683 patients from January 1994 to December 2006 with scar contracture of the neck, aged 1.5 - 67.0 years, who were scheduled for elective plastic surgery under general anesthesia in Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Based on the results of the preoperative airway assessment, the patients were classified into group 1 (including 1375 patients with the atlanto-occipital extension of > 20 degrees and the Mallampatti's grade I or II) and group 2 (containing 308 patients with the atlanto-occipital extension of < 20 degrees and the Mallampatti's grade III or IV. In group 1, the intravenous induction and maintenance of anesthesia and succinylcholine for muscle relaxation were used. The intubation was done using a modified Macintosh technique. In group 2, the total intravenous anesthesia (TIVA) or the sevoflurane inhalation anesthesia was chosen and the spontaneous breathing was reserved during anesthesia. The intubation was performed by a fiberoptic stylet laryngoscope (FOSL). The number of intubation attempts, intubation time and relative complications were observed and recorded in all patients. RESULTS In group 1, the intubation was accomplished during the first attempt in 1279 cases (93%) and the intubation time was < 3 minutes in 1304 cases (95%). In group 2, the intubation was completed by the first attempt in 114 patients (37%) and 123 patients had an intubation time of < 3 minutes (40%). Tracheal intubation was successful by the second or third attempt in 96 patients in group 1 and 156 patients in group 2. Thirty-eight patients required four or more attempts which only occurred in group 2. The incidence of traumatic complication was 2.6% and 9.7% with one intubation attempt in groups 1 and 2, respectively, 12.5% and 17.0% with multiple intubation attempts (one vs multiple attempts in both groups, P < 0.001). All non-traumatic complications occurred in group 2 and laryngospasm and hypoxemia were more common in patients using the TIVA compared to those using the sevoflurane inhalational anesthesia (P < 0.001). CONCLUSIONS This study demonstrated that with a precise airway evaluation, an adequate preoperative preparation and a pre-planned failed intubation strategy, the anesthetist who was experienced in the difficult airway management could safely perform airway control and tracheal intubation under general anesthesia in patients with scar contracture of the neck. We believe that this technique may be very valuable for the management of a known difficult airway because it is comfortable for the patient and saves time for the anesthetist.

BACKGROUND: We designed this prospective self-controlled study to assess whether cricoid pressure hampers placement of and ventilation through the ProSeal laryngeal mask airway (ProSeal LMA) in anesthetized, paralyzed adult patients.METHODS: After induction of anesthesia, the ProSeal LMA was inserted using the introducer tool with cricoid pressure advanced as far as possible, and the cuff, pressure was set at 60 cm H2O. Ventilation adequacy and anatomic position were scored using measures previously described for ProSeal LMA assessment. Airway., seal pressure was recorded. Cricoid pressure was then released, the ProSeal LMA further advanced and reseated, and the assessment repeated.RESULTS: Lung ventilation scores, anatomic position scores, and airway seal pressure were significantly better after release of cricoid pressure and reseating of the ProSeal LMA than in the first position, where the ProSeal LMA was seated with cricoid pressure (P < 0.05). Expiratory tidal volume during intermittent positive pressure ventilation was similar with and without cricoid pressure, but peak inspiratory pressure decreased from 28 cm H2O with cricoid pressure to 14 cm H2O without cricoid pressure (P < 0.05).CONCLUSIONS: Cricoid pressure applied before insertion hampered proper placement of the ProSeal LMA. Temporary cricoid pressure release during insertion allowed the device to be advanced to the proper position. After correct placement of the ProSeal LMA, application of cricoid pressure did not change tidal volume, but produced a significant increase in peak inspiratory pressure.

Summary Background: The authors found no study assessing the efficacy of small‐dose narcotics on the cardiovascular response from intubation in children, so they observed the effects of fentanyl 2 μ g·kg −1 and sufentanil 0.2 μ g·kg −1 on the cardiovascular changes during laryngoscopy and intubation in children. Methods: Ninety‐three children aged 3–9 years were randomized to one of three groups to receive the following treatments in a double‐blind manner: normal saline (group C), fentanyl 2 μ g·kg −1 (group F) and sufentanil 0.2 μ g·kg −1 (group S) 2 min before induction. Noninvasive blood pressure (BP) and heart rate (HR) were recorded before anesthesia induction (baseline value), immediately before intubation (postinduction values), at intubation and 5 min after intubation at 1‐min interval. Results: Tracheal intubation caused significant increases in BP and HR in the three groups compared with baseline values. BP and HR at intubation and after intubation and their maximum values during observation were significantly lower in groups F and S than in group C ( P < 0.05). The mean percent increases of systolic blood pressure (SBP) and HR at intubation were significantly lower in group S, 7% and 10%, than in group F, 17% and 25% ( P < 0.05). The increases in SBP and HR of more than 30% of baseline values during the observation period were significantly higher in group F, 27% and 43%, than in group S, 0% and 3% ( P < 0.05). Conclusions: When used as part of anesthesia induction with propofol in children, sufentanil 0.2 μ g·kg −1 2 min before induction is more effective in attenuating the cardiovascular intubation response than fentanyl 2 μ g·kg −1 .

OBJECTIVE:To compare the ProSeal laryngeal mask airway (PLMA) and the standard laryngeal mask airway (SLMA) for intermittent positive pressure ventilation (IPPV) in a randomized auto control design. METHODS:Fifty adult patients with American Society of Anesthesiologists (ASA) physical status 1-2, scheduled for elective plastic surgery under general anesthesia were recruited. After the routine intravenous anesthesia induction, the PLMA and the SLMA were inserted randomly in sequence into each patient and inflated to an intracuff pressure of 60 cm H(2)O (1 cm H(2)O=0.098 kPa), airway seal pressure and lung ventilation satisfaction were evaluated, and fiberoptic (FOB) scores of the cuff anatomic position were measured. The mean expired volume and the mean peak inspiratory pressure of five continuous breaths were calculated after IPPV with 10 ml/kg tidal volume was performed. RESULTS:Without cuff inflation, airway seal pressure was higher with the PLMA than with the SLMA (P<0.05), and adequate or acceptable lung ventilation was obtained in 46 (92%) patients with the PLMA, but only 22 (44%) patients with the SLMA. When the air volume required to obtain an intracuff pressure of 60 cm H(2)O, adequate lung ventilation was obtained in 50 patients with the PLMA, but only 28 patients with the SLMA, and the inflation volume and sequential airway seal pressure were higher with the PLMA than with the SLMA (both P<0.05), and the airway seal pressure with the PLMA was not less than with the SLMA in each patient. The ventilation volume was higher with the PLMA than with the SLMA, except in 2 patients. The FOB score of the cuff position was lower with the PLMA than with the SLMA (P<0.05). The mean expired tidal volume and the mean peak inspiratory pressure were not significantly different between 29 patients with the PLMA and 21 patients with the SLMA for airway maintenance during operation (both P>0.05). CONCLUSION:Compared with SLMA, PLMA can achieve a higher airway seal pressure and potentially isolate the glottis and the upper esophagus, and is safer and more effective for positive pressure ventilation.

BACKGROUNDThe authors found no study comparing potency and duration of action of vecuronium and atracurium in healthy Chinese, so they compared the dose-response relations of vecuronium and atracurium in anesthetized Chinese adult patients and evaluated the time-course of action of two drugs following administration of equipotent doses.METHODSSixty patients, ASA grade 1, aged from 17 to 50 yr, scheduled for elective plastic surgery were randomly distributed to either the vecuronium or the atracurium group. General anesthesia was maintained with 60% nitrous oxide in oxygen (N2O-O2), thiopental and fentanyl. Neuromuscular function was assessed using a accelerometer with train-of-four (TOF) stimulation at the wrist every 12 sec, and the percentage of depression of first twitch (T1) was used as the study parameter. The dose-response relations of vecuronium and atracurium were determined using the cumulative dose-response technique.RESULTSThe cumulative dose-response curve of vecuronium was shifted to the left in a parallel fashion compared with that of atracurium. As assessed by linear regression, the potency ratio of vecuronium:atracurium was 6:1. There were significant differences in the ED50, ED90, and ED95 between the two drugs. After the intravenous administration of equipotent doses of both drugs (1.5 x ED95), the duration of peak effect, clinical duration, recovery index, and total duration were not significantly different between the two drugs.CONCLUSIONSThe neuromuscular blocking potency of atracurium is approximately 17% that of vecuronium in anesthetized Chinese adult patients. Following equipotent doses, the time course of action of atracurium is similar to that of vecuronium.

Objective:To describe the use of the GlideScope in comparison with direct laryngoscopy for elective surgical patients requiring tracheal intubation. Methods:Two hundred patients. ASA I - I scheduled for elective surgery under general anesthesia requiring orotracheal intubation were selected. Information was collected identifying the patient demographics and airway assessment features （Mallampati oropharyngeal scale, thyromenta distance and mouth opening）. In a random crossover design, after induction of anesthesia and neuromuscular block, the laryngoscopes were inserted in turn, and the views of the glottis at laryngoscopy （Cormack and Lehane scores） were compared. The tracchea was intubated using either the standard Macintosh laryngoscope or GlideScope after the second grading at laryngoscopy was done. Complications associated with intubating were recorded. Results: There were 200 patients including 107 males and 93 females, with mean age being 52±13 years, height 164. 8±11. 3 cm, weight 64. 0±11. 5 kg, thyromental distance 6. 9±1. 1 cm, and mouth opening 5. 7±0. 5 cm. There was a significant association between the preoperative view of the oropharynx （Mallampati score） and the view of the glottis at laryngoscopy for both the direct Macintosh laryngoscope （P＜0. 001） and the GlideScope （P＜0. 001）. A-mong 200 patients, 106 patients had the same C＆L grade, 91 of remaining patients showed improvement in the C＆L grade （P＜0. 001） obtained with GlideScope compared with the direct Macintosh laryngoscope. 3 of remaining patients showed better view of the glottis（C＆L grade） with the direct Macintosh laryngoscope （grade 1） than with GlideScope （grade 2）. There were no cases of failure to be intubated. There were no cases of dental or mucosal injury in all patients. Conclusion: GlideScope videolaryngoscope yielded comparable or superior laryngeal view compared with Macintosh laryngoscope. The new type of laryngoscope may have potential advantages for managing the difficult airway.

BACKGROUND:Previous studies have demonstrated a significant difference in the circulatory responses in adults to fiberoptic nasotracheal intubation (FNI) and fiberoptic orotracheal intubation (FOI). But, it is unknown whether there is a clinically relevant difference in the circulatory responses in children to these two intubation methods. METHODS:In this randomized clinical study, we compared the arterial blood pressure and heart rate changes during FNI and FOI in 66 children, ASA physical status I-II, aged 3-9 yr scheduled for elective plastic surgery. After anesthesia induction with fentanyl-propofol and vecuronium, fiberoptic intubation was performed. Noninvasive arterial blood pressure and heart rate were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation, and every minute for the first 5 min after intubation. The maximum values of arterial blood pressure and heart rate during the observation were also recorded. RESULTS:The total intubation time was significantly longer in the FNI group than in the FOI group. Both FOI and FNI caused significant increases in arterial blood pressure and heart rate compared with the baseline and postinduction values. Arterial blood pressure and heart rate at intubation and after intubation, and their maximum values during the observed periods were significantly lower in the FNI group compared with the FOI group. The times required to reach the maximum values of systolic blood pressure and heart rate were significantly longer in the FNI group than in the FOI group, but the times required for recovery of systolic blood pressure and heart rate to postinduction values were significantly shorter in the FNI group than in the FOI group. After the intubation, the times required to reach the peak levels of systolic blood pressure and heart rate were not significantly different between the two groups. CONCLUSIONS:Both FOI and FNI can cause significant circulatory responses in healthy anesthetized children, and the circulatory responses to FNI are fewer and of a shorter duration than those to FOI.