Age-related changes in intraoperative mean values of nociceptive response in patients undergoing non-cardiac surgery under general anesthesia: A retrospective cohort study

Intraoperative nociception is affected by preoperative factors, surgical invasiveness, and anesthesia. Although age-related changes in nociception in conscious humans have been well examined, those in intraoperative nociception in unconscious patients under general anesthesia are unknown. To clarify associations between age and intraoperative nociception under general anesthesia, we performed a retrospective cohort study in consecutive patients of all ages undergoing non-cardiac surgery under general anesthesia from January 2019 to July 2023. The intraoperative nociception value in each surgery was assessed by the averaged value of nociceptive response (mean NR) index during surgery. Patient characteristics, including age, sex, body mass index (BMI), emergent surgery, preoperative serum C-reactive protein (CRP) level, and comorbidities were also collected. After excluding patients with missing data of CRP and mean NR index, 22,061 patients were enrolled, and were divided into low, intermediate, and high surgical risk groups. Multivariable regression analysis showed a significant association between age and mean NR index in all three surgical procedure risk groups. The preoperative variables of CRP levels, BMI, emergent surgery, atrial fibrillation, renal failure, and long-term steroid use also showed significant associations with mean NR index in all three groups. Sensitivity analysis showed that intraoperative mean NR index was higher in younger children than that in both older children and younger adults, and it gradually increased again in older adults to the same level as in younger children. In conclusion, there is likely an association between age and intraoperative mean NR index in patients under general anesthesia.

The Impact of Nociception Monitor-Guided Multimodal General Anesthesia on Postoperative Outcomes in Patients Undergoing Laparoscopic Bowel Surgery: A Randomized Controlled Trial

BACKGROUND

Excess surgical stress responses, caused by heightened nociception, can lead to elevated levels of postoperative inflammation, resulting in an increased incidence of complications after surgery. We hypothesized that utilizing nociception monitor-guided multimodal general anesthesia would exert effects on postoperative outcomes (e.g., serum concentrations of C-reactive protein (CRP) after surgery, postoperative complications).

METHODS

This single-center, double-blinded, randomized trial enrolled ASA class I/II adult patients with normal preoperative CRP levels, scheduled for laparoscopic bowel surgery. Patients were randomized to receive either standard care (control group) or nociception monitor-guided multimodal general anesthesia using the nociceptive response (NR) index (NR group), where NR index was kept below 0.85 as possible. The co-primary endpoint was serum concentrations of CRP after surgery or rates of 30-day postoperative complications (defined as Clavien-Dindo grades ≥ II).

MAIN RESULTS

One hundred and four patients (control group, n = 52; NR group, n = 52) were enrolled for analysis. The serum CRP level on postoperative day (POD) 1 was significantly lower in the NR group (2.70 mg·dL-1 [95% confidence interval (CI), 2.19-3.20]) than in the control group (3.66 mg·dL-1 [95% CI, 2.98-4.34], p = 0.024). The postoperative complication rate was also significantly lower in the NR group (11.5% [95% CI, 5.4-23.0]) than in the control group (38.5% [95% CI, 26.5-52.0], p = 0.002).

CONCLUSIONS

Nociception monitor-guided multimodal general anesthesia, which suppressed intraoperative nociception, mitigated serum concentrations of CRP level, and decreased postoperative complications after laparoscopic bowel surgery.

Intraoperative nociception and postoperative inflammation associated with the suppression of major complications due to thoracic epidural block after pleurectomy/decortication for malignant pleural mesothelioma under general anesthesia: A retrospective observational study

A recent study showed that thoracic epidural block (TEB) suppressed the occurrence of major complications after pleurectomy/decortication (P/D) for malignant pleural mesothelioma (MPM) under general anesthesia. To investigate the mechanisms underlying the correlation, both acute inflammatory status and intraoperative nociception were evaluated in the present study. In a single-institutional observational study, consecutive adult patients undergoing P/D were enrolled from March 2019 to April 2022. Perioperative acute inflammatory status was evaluated using differential White blood cell (WBC) counts and serum concentration of C-reactive protein (CRP) both before and after the surgery on postoperative day (POD) 1. The averaged value of nociceptive response index during surgery (mean NR) was obtained to evaluate the level of intraoperative nociception. Multivariable logistic regression analysis was performed to determine the association between perioperative variables and major complications Postoperative major postoperative complication was defined as Clavien-Dindo grades ≥ III. We conducted this study with 97 patients. After logistic regression analysis showed that general anesthesia without TEB was a sole risk factor for major complications, patients were divided into 2 groups: general anesthesia with and without TEB. The incidence of major complications was significantly lower in patients with TEB (33.3%, n = 33) than in those without TEB (64.1%, n = 64, P < .01). Although there was no significant difference in the CRP level between 2 groups, the lymphocyte-to-monocyte ratio (LMR) on POD 1 in patients with TEB was significantly higher than that in patients without TEB (P = .04). The mean NR was significantly lower in patients with TEB than that in those without TEB (P = .02). Both lower mean NR during surgery and higher LMR on POD 1 are likely associated the suppression of major complications due to TEB after P/D under general anesthesia. Decreases in the postoperative acute inflammatory response, caused by the reduction of intraoperative nociception due to TEB, may help suppress major complications after P/D.

Association between averaged intraoperative nociceptive response index and postoperative complications after lung resection surgery

OBJECTIVES

Since postoperative complications, defined as Clavien-Dindo grade ≥II, correlate with long-term survival after lung resection surgery in patients with primary lung cancer, identification of intraoperative risk factors for postoperative complications is crucial for better perioperative management. In the present study, we investigated the possible association between intraoperative variables for use in anaesthetic management and Clavien-Dindo grade ≥II.

METHODS

In this multi-institutional observational study, consecutive adult patients undergoing video-assisted thoracic surgery for primary lung cancer under general anaesthesia from March 2019 to April 2021 were enrolled. All patients were divided into 2 groups with Clavien-Dindo grade <II and ≥II. Uni- and multivariable analyses were performed to identify intraoperative risk factors.

RESULTS

After univariable analysis between patients with Clavien-Dindo grade <II (n = 415) and ≥II (n = 121), multivariable analysis revealed higher averaged nociceptive response (NR) index during surgery (mean NR), male sex, lower body mass index, longer duration of surgery, higher blood loss and lower urine volume, as independent risk factors for postoperative complications. In sensitivity analysis, based on the cut-off value of mean NR for postoperative complications, all patients were divided into high and low mean NR groups. The incidence of postoperative complications was significantly higher in patients with high mean NR (n = 332) than in patients with low mean NR (n = 204; P < 0.001).

CONCLUSIONS

Higher mean NR, as intraoperative variables for use in anaesthetic management, is associated with the higher incidence of postoperative complications after primary lung cancer surgery.

Association between thoracic epidural block and major complications after pleurectomy/decortication for malignant pleural mesothelioma under general anesthesia

Introduction

A curative-intent surgical procedure, pleurectomy/decortication, for malignant pleural mesothelioma is accompanied by a high incidence of major postoperative complications. Although epidural block, which suppresses nociception during and after surgery, reportedly has both benefits and disadvantages in terms of outcomes after thoracic surgery for other diseases, the effects of epidural block on major complications after pleurectomy/decortication have not been evaluated. The aim of this study was to evaluate the association between epidural block and major postoperative complications following pleurectomy/decortication.

Methods

In a single-institutional observational study, consecutive adult patients undergoing pleurectomy/decortication under general anesthesia were enrolled from March 2019 to December 2021. Multivariable logistic regression analysis was performed to determine the association between perioperative variables and major complications. Next, patients were divided into two groups: general anesthesia with and without epidural block. Incidences of major postoperative complications, defined as Clavien-Dindo grades≥III, were compared between groups.

Results

In all patients enrolled with American Society of Anesthesiologists (ASA) physical status II or III (n=99), general anesthesia without epidural block was identified as a sole risk factor for major complications among perioperative variables. The incidence of major complications was 32.3% (95% CI 19.1% to 49.2%) in patients with epidural block (n=34), which was significantly lower than 63.1% (95% CI 50.9% to 73.8%) in patients without epidural block (n=65). In sensitivity analysis in patients with ASA physical status II alone, the same results were obtained.

Conclusion

Epidural block is likely associated with reduction of the incidence of major complications after pleurectomy/decortication for malignant pleural mesothelioma under general anesthesia.

Quantitative evaluation of the effects of interscalene block on physiological responses to the balance between nociception and anti-nociception among inpatients undergoing total shoulder arthroplasty under general anesthesia

Although the suppression of physiological responses to the balance between nociception caused by surgical trauma and anti-nociception due to anesthesia during total shoulder arthroplasty (TSA) is relevant for better perioperative managements, quantitative evaluations of the effects of ultrasound-guided interscalene brachial plexus block (ISB) on physiological responses have not been performed. Physiological responses were assessed using the nociceptive response (NR) index. In this multi-institutional observational study, associations between ISB and NR values were examined among inpatients undergoing TSA under general anesthesia between March 2019 and January 2021. The effects of ISB on acute postoperative pain and major complications within 30 days after surgery were also examined. NR values after skin incision clearly showed significant suppressions of physiological responses in patients undergoing TSA with ISB (n = 60), compared to those without ISB (n = 24). Acute postoperative pain on the day of surgery was also significantly less in patients with ISB than in those without ISB. Postoperative complications, classified by Clavien-Dindo grades, showed no significant differences between patients with and without ISB. A propensity score-matched sensitivity analysis confirmed the same results in patients with (n = 21) and without ISB (n = 21). In conclusion, suppression of physiological responses to the balance between nociception and anti-nociception by ISB can be quantitatively evaluated by NR index during TSA.

Intra-operative nociceptive responses and postoperative major complications after gastrointestinal surgery under general anaesthesia: A prospective cohort study

BACKGROUND

Surgical procedures stimulate nociception and induce physiological responses according to the balance between nociception and antinociception. The severity of surgical stimuli is associated with major postoperative complications. Although an intra-operative quantitative index representing surgical invasiveness would be useful for anaesthetic management to predict and prevent major complications, no such index is available.

OBJECTIVES

To identify associations between major complications after gastrointestinal surgery and intra-operative quantitative values from intra-operative nociception monitoring.

DESIGN

A multi-institutional observational study.

SETTING

Two university hospitals.

PATIENTS

Consecutive adult patients undergoing gastrointestinal surgery under general anaesthesia.

MAIN OUTCOME MEASURES

Averaged values of nociceptive response index from start to end of surgery (mean NR index) and risk scores of the Surgical Mortality Probability Model (S-MPM) were calculated. Pre and postoperative serum C-reactive protein (CRP) levels were obtained. After receiver-operating characteristic (ROC) curve analysis, all patients were divided into groups with high and low mean nociceptive response index. Associations between mean nociceptive response index and postoperative major complications, defined as Clavien-Dindo grade at least IIIa, were examined using logistic regression analysis.

RESULTS

ROC curve analysis showed a nociceptive response index cut-off value for major complications of 0.83, and we divided patients into two groups with mean nociceptive response index less than 0.83 and at least 0.83. The incidence of major complications was significantly higher in patients with mean nociceptive response index at least 0.83 (23.1%; n = 346) than in patients with mean nociceptive response index less than 0.83 (7.7%; n = 443; P < 0.001). Multivariate analysis revealed emergency surgery, S-MPM risk score, mean nociceptive response index and postoperative CRP levels as independent risk factors for major complications.

CONCLUSION

Mean nociceptive response index during surgery likely correlates with major complications after gastrointestinal surgery.

TRIAL REGISTRATION

The current observational study had no intervention, and was therefore, not registered.

Adrenal pheochromocytoma treated by combination of adrenal arterial embolization and radiofrequency ablation

Combined therapy with adrenal arterial embolization and RF ablation may represent a useful therapeutic option with curative properties in select patients with pheochromocytoma.

Systematic evaluation of magnetic sensitivities of anisotropic magnetoresistive sensors at liquid helium temperature for superconducting cavities

Trapped magnetic flux in bulk superconductors reduces the quality factor Q in superconducting radio-frequency (SRF) cavities. However, the mechanisms underlying flux trapping and radio-frequency loss are not well understood. Detailed observation of the magnetic distributions is important for understanding such phenomena. Magnetic field mapping is useful for observing the magnetic field distribution around SRF cavities. Measuring the change in the magnetic field around the cavity elucidates the flux trapping behavior. Anisotropic magnetoresistive (AMR) sensors are inexpensive and small devices that can detect magnetic flux density. The magnetic sensitivities of AMR sensors need to be evaluated at liquid helium temperature for the magnetic field mapping of SRF cavities. In this study, a test stand was constructed to calibrate the magnetic sensitivities of AMR sensors in liquid helium, and 110 AMR sensors were tested using this stand. The magnetic sensitivities were evaluated systematically. A solenoid coil was used to control the uniform external magnetic field and to measure the magnetic sensitivity at low temperatures. All AMR sensors exhibited suitable sensitivities to the magnetic field around the SRF cavity. The variation in these sensitivities in all AMR sensors was ∼1%. The AMR sensors were found to have sufficient sensitivity for mapping the magnetic field around the exterior surface of the SRF cavity.

Three-day tracheal intubation manikin training for novice doctors using Macintosh laryngoscope, McGRATH MAC videolaryngoscope and Pentax AirwayScope

BACKGROUND

We compared the intubation skills obtained by novice doctors following training using 3 instruments, the conventional Macintosh laryngoscope (Mac) and 2 types of indirect video-laryngoscopes (McGrathTM-MAC: McGrath (McG) and AirwayScope (AWS)), to determine the most appropriate instrument for novice doctors to acquire intubation skills, especially focusing on visual confirmation of vocal cords, during a 3-day intensive manikin training program.

METHODS

Fifteen novice doctors who did not have sufficient experience in endotracheal intubation (ETI) and consented to participate in this study were included. We used AirSim and AMT (Airway management Trainer) manikins. First, an experienced anesthesiologist instructed the trainees on using the 3 instruments for a few minutes. Then, after familiarizing themselves with each device for 10 minutes, the participants attempted ETI on the 2 manikins with the 3 devices used in random order. Intubations with each device were practiced and performed for 3 successive days. We assessed the percentage of glottic opening (POGO) score, successful intubation rate and tracheal intubation time for each participant, with each device, and on each day.

RESULTS

In the first manikin, AirSim, POGO scores in the McG and AWS groups were significantly higher than those in the Mac group on all 3 days (P < .0001). The number of intubation failures in the Mac group decreased from 2 cases on day 1, to 1 case on day 2 and zero cases on day 3. There were no failures in the McG and AWS groups on any of the days. With the second manikin, AMT, POGO scores in the Mac group were significantly lower than those in the McG and AWS groups on all 3 days. There were no intubation failures in the AWS group on all 3 days. In the Mac group, the number of intubation failures decreased from 3 on day 1, to 2 on day 2 and zero failures on day 3. In the McG group, there were only 3 failures on day 1.

CONCLUSION

The 2 types of indirect video-laryngoscopes (McGRATH and AirwayScope) were demonstrated to be suitable instruments for novice doctors to achieve higher POGO scores in a 3-day intensive ETI training.

Modified model for predicting early C-reactive protein levels after gastrointestinal surgery: A prospective cohort study

Background

Postoperative serum concentration of C-reactive protein (CRP) is one of the objective quantitative indices integrating the effects of preoperative and intraoperative variables. Higher levels of CRP after gastrointestinal surgery are associated with major postoperative complications. To develop a model for predicting CRP levels on postoperative day (POD) 1 in surgical patients both with and without serious conditions and comorbidities, we modified the previous formula for prediction of CRP levels on POD1, and assessed the accuracy of our modified predictive formula for CRP levels.

Material and methods

Consecutive patients of all ages undergoing gastrointestinal surgery under general anesthesia were enrolled in this single-institution prospective cohort study. We developed a modified predictive formula in a calculation cohort. Next, associations between measured CRP levels on POD1, predicted CRP levels on POD1 using the previous and modified models, and major complications after surgery were examined in a validation cohort.

Results

We obtained the following model in the calculation cohort (n = 222): Modified model for predicting CRP levels on POD1 (mg•dL^-1) = -10.13 + 0.0025 Duration of surgery (min) + 15.9 Mean Nociceptive Response (NR) + 0.66 Preoperative CRP level (mg•dL^-1). In the validation cohort (n = 440), there was a significant association between measured and predicted CRP levels on POD1 (P < 0.001) No significant difference between the measured and predicted CRP levels using the modified model was observed (P = 0.847). There were also significant associations between the predicted CRP levels and major complications after surgery.

Conclusion

CRP levels predicted using duration of surgery, mean NR, and preoperative CRP levels are likely identical to measured CRP levels on POD1, being associated with major complications after gastrointestinal surgery.

Association between intraoperative nociception and surgical invasiveness in patients undergoing non-cardiac surgery under general anesthesia: a retrospective cohort study

There are several indexes of intraoperative nociception during surgery under general anesthesia. Although a higher degree of surgical invasiveness increases intraoperative nociception, an association between the index of intraoperative nociception and severity of surgical invasiveness has not been reported. We hypothesized that there is associations between averaged values of nociceptive response (NR) throughout surgery (mean NR), as the index of intraoperative nociception, and surgical severity codes in the Surgical outcome risk tool (SORT) or procedure risk codes in the Surgical mortality probability model (S-MPM). The primary outcome was the association between mean NR and severity scores of surgical procedure. Hence, a single institutional retrospective cohort study was performed in consecutive patients undergoing non-cardiac surgery under general anesthesia from June 2018 to May 2019. There were significant increases in the three categories of procedure risk in the S-MPM corresponding to the increase in mean NR values in 5090 patients. In the SORT, the highest intensity in the four categories of surgical severity also significantly correlated with the increase in mean NR values. Increasing intensity of intraoperative nociception is likely associated with higher severity codes of surgical invasiveness in prediction models for postoperative morbidity and mortality.

Acute and chronic neuropathic pain profiles after video-assisted thoracic surgery: A prospective study

Acute postsurgical pain, probably including acute neuropathic pain (ANeP), starts at the early postoperative period, and chronic postsurgical pain including chronic neuropathic pain (CNeP) persists at least 3 months after surgery. Although it must be important for prevention and treatment of acute and chronic postoperative pain to reveal the time course of postoperative neuropathic characteristics, a neuropathic pain profile after surgery has not been evaluated.Pain status at the surgical site in adult patients who underwent video-assisted thoracic surgery (VATS) for lung cancer was prospectively assessed until 12 months after surgery. Neuropathic characteristics were assessed using the Douleur Neuropathique 4 (DN4) questionnaire until 6 days after surgery and the DN2 questionnaire throughout the study.Twenty-seven patients were enrolled in this study. Pain intensity at surgical sites were significantly higher at 1 and 6 days after surgery during resting state, and were also significantly higher at 3, 6, and 12 months after surgery during movement than those before surgery. The incidence of ANeP was 33.3% at 1 day, and 18.5% at 6 days after surgery. The incidence of CNeP decreased to 12.5% at 3 months, 5.0% at 6 months, and 0.0% at 12 months after surgery. The number of neuropathic characteristics, assessed by DN2 scores, significantly increased at 1 and 6 days after surgery, compared to those before surgery. DN2 scores at 3, 6, and 12 months after surgery, however, showed no significant differences compared to those before surgery.In patients with acute postsurgical pain, 20% to 30% of patients show ANeP characteristics, and the incidence of CNeP gradually decreases after VATS in patients with chronic postsurgical pain.

Effects of Simulation Study of High Neuraxial Block During Epidural Analgesia for Labor Pain on Pre/Posttest Evaluation in Junior Clinical Trainees

Background

Since a high neuraxial block is one of the serious complications in obstetric anesthesia, simulation training is required for the education of rapid diagnosis and treatment of this complication.

Objectives

This study aimed to evaluate the effects of a simulation study of the high neuraxial block during epidural analgesia for labor pain on pre- and post-simulation tests in junior clinical trainees, who had graduated a medical school within one or two years and being under a two-month program for anesthesia during the Japanese Postgraduate Medical Education.

Methods

Twenty-two junior clinical trainees participated in this study from September 2016 to May 2017. Before the simulation training, the participants answered a pretest, providing written responses on “how to approach and treat the rapid spread of anesthesia (high neuraxial block) in painless epidural delivery” in a bullet-point form. The number of correct answers to 12 items was counted for each participant. These items were as follows: mask ventilation, preparation for tracheal intubation, oxygenation, supraglottic airway placement, checking the breathing, checking oxygen saturation using pulse oximetry, checking blood pressure, ephedrine injection, checking epidural tube, assessing the level of sensory block, assessing the level of consciousness, and left uterine displacement. After performing our original training, all participants were debriefed and written responses were obtained to a posttest containing the same content as the pretest.

Results

The percentage of correct answers significantly increased from 8.3 to 16.7% (P = 0.041) after training. The response rates for “mask ventilation” and “check epidural tube” significantly increased from 13.6 to 54.5% (P = 0.004) and from 4.5 to 27.3% (P = 0.039), respectively, after training.

Conclusions

Simulation training is likely an effective method for junior clinical trainees on studying diagnosis and treatment of high neuraxial block during epidural analgesia in parturient patients.

The Basic Study of the Mechanism of Propofol-Related Infusion Syndrome Using a Murine Skeletal Muscle Injury Model

Background

The pathophysiological mechanism of propofol-related infusion syndrome (PRIS) is believed to be due to the injury to the mitochondrial electron transport chain and the resultant metabolic disorders that are caused by both propofol agents and the lipid solvent. However, the mechanisms and causative factors of PRIS have not been fully elucidated.

Objectives

The aim of this study was to evaluate the possibility of a research model using the culture of differentiated C2C12 cells for fundamental research of PRIS.

Methods

First, differentiated C2C12 cells were cultured accompanied by several concentrations of chemical reagents of 2,6-diisopropylphenol (2,6 DIP) or dimethyl sulfoxide (DMSO) for 60 hours and the cell death rate was examined by trypan blue staining. Second, The cells were incubated with a commercially available propofol reagent or lipid reagent for 48 hours. The supernatant fluid of the cell culture medium was gathered and the numbers of floating cells were measured by cell counter. To investigate the mitochondrial disorder by the propofol preparation, JC-1, an experiment using fluorescent reagent, was performed for the 48 hours with 100 µg/mL propofol incubation.

Results

The rate of cell death was increased with elevating concentrations both of chemical reagents of 2,6 DIP group and dimethyl sulfoxide group. The rates of cell death were significantly higher in the 2,6 DIP group than DMSO group. The numbers of floating cells were increased with elevating concentrations both commercially available propofol reagent and lipid reagent groups. The decreased red/green fluorescence ratio by JC-1 staining in the propofol 100µg/mL group proved an attenuated mitochondrial membrane potential.

Conclusions

The dose-dependent cell damage induced by the propofol reagents and a lipid solvent may provide a proposed model as a basic experimental model for further investigations into PRIS.

Association between intraoperative nociception and postoperative complications in patients undergoing laparoscopic gastrointestinal surgery

A higher degree of surgical invasiveness, which increases intraoperative nociception, might induce postoperative complications. Although several nociceptive indices for use during surgery are available in clinical practice, association between intraoperative nociception and postoperative complications has not been reported. An index representing intraoperative nociception, which is the averaged value of Nociceptive Response throughout the surgery (mean NR) was applied to examine the association in the present study. The retrospective study evaluated consecutive adult patients undergoing laparoscopic gastrointestinal surgery, American Society of Anesthesiologists-physical status (ASA-PS) I or II, whose preoperative C-reactive protein level was < 0.3 mg dL^-1. We first used ordinal logistic analysis to examine the association between preoperative and intraoperative risk factors and complications graded by the Clavien-Dindo classification. Next, we performed propensity score matched analysis to evaluate the effects of mean NR throughout surgery on postoperative complications. Ordinal logistic analysis (n = 158) revealed that duration of surgery (P < 0.001), mean NR during surgery (P = 0.002), and ASA-PS (P = 0.016) were risk factors for postoperative complications. Then all patients were divided into two propensity score matched groups, based on a mean NR of < 0.85 and ≥ 0.85, with matching for age, ASA-PS, body mass index and duration of surgery. The severity of postoperative complications was significantly higher in the high NR group than in the low NR group (P = 0.005). In conclusion, there was likely an association between intraoperative nociception and postoperative complications in patients without serious preoperative conditions and comorbidities.

Effects of Thoracic Paravertebral Block on Nociceptive Levels After Skin Incision During Video-Assisted Thoracoscopic Surgery

Background

Regional anesthesia provides excellent analgesic effects after surgery. However, the effects of regional anesthesia on nociceptive levels during surgery under general anesthesia have not been quantitatively evaluated. To reveal the effects of thoracic paravertebral block (PVB) on nociceptive levels after skin incision during general anesthesia, we performed a retrospective cohort study in patients without serious preoperative conditions or comorbidities undergoing elective video-assisted thoracoscopic surgery (VATS). Nociceptive levels during general anesthesia were calculated using our previously determined Nociceptive Response (NR) equation, which utilizes common hemodynamic parameters.

Material/Methods

Data on 77 adult patients who underwent VATS from May 2018 to August 2018 were retrospectively obtained from our institutional database. We then performed propensity score matching between patients who received thoracic PVB (PVB group: n=29) and those who did not (Control group: n=48). The averaged values of systolic blood pressure (SBP), heart rate (HR), perfusion index (PI), bispectral index (BIS), and NR from 10 to 5 minutes before skin incision (T0), 5 to 10 minutes (T1), 10 to 15 minutes (T2), 15 to 20 minutes (T3), and 20 to 25 minutes after skin incision (T4), were calculated.

Results

Twenty-four propensity score-matched patients in each group were analyzed. Mean NR values at T1 and T2 in the PVB group were significantly lower than those in the Control group. SBP, HR, PI, and BIS, however, showed no significant differences between the 2 groups, except for SBP at T2.

Conclusions

Thoracic PVB prevented an increase in NR values, which quantitatively represent nociceptive levels under general anesthesia, in patients undergoing VATS.

C-reactive Protein Level on Postoperative Day One is Associated with Chronic Postsurgical Pain After Mastectomy

Background

C-reactive protein (CRP) is an acute phase reactant released in response to inflammation or tissue injury. Inflammation is one of the pathogenic factors related to transition from acute postsurgical pain (APSP) to chronic postsurgical pain (CPSP). Although several risk factors are reportedly associated with CPSP, the effects of CRP levels on CPSP have not been examined.

Objectives

The present study investigated the relationship between perioperative risk factors, including CRP levels on postoperative day one and CPSP, in patients undergoing mastectomy.

Methods

Preoperative anxiety and depression levels were evaluated in female patients undergoing mastectomy under general anesthesia, with or without peripheral nerve block. Patients with chronic preoperative pain and/or preoperative breast pain were excluded. The intensity of postoperative pain was prospectively examined one and six days, and three and twelve months after surgery using a numerical rating scale (NRS).

Results

The current researchers conducted univariate and multivariate linear regression analyses to explore risk factors for CPSP in 36 patients. Patient demographics, preoperative psychological states, and anesthetic managements showed no relationship with CPSP. On the other hand, pain intensity of APSP and CRP levels on postoperative day one was significantly associated with the pain intensity of CPSP.

Conclusions

Postoperative CRP level is likely to be associated with the development of CPSP after mastectomy.

Development of a Hemodynamic Model Using Routine Monitoring Parameters for Nociceptive Responses Evaluation During Surgery Under General Anesthesia

BACKGROUND Routine hemodynamic monitoring parameters under general anesthesia, such as heart rate (HR), systolic blood pressure (SBP), and perfusion index (PI), do not solely reflect intraoperative nociceptive levels. We developed a hemodynamic model combining these 3 parameters for nociceptive responses during general anesthesia, and evaluated nociceptive responses to surgical skin incision. MATERIAL AND METHODS We first retrospectively performed discriminant analysis using 3 values - HR, SBP, and PI - to assess response to skin incision during tympanoplasty, laparoscopic cholecystectomy, and open gastrectomy to determine if combined use of these parameters differentiates nociceptive levels among these 3 surgeries. Secondly, ordinal logistic regression analysis was applied using the 3 parameters to develop an equation representing nociceptive response during general anesthesia, and then evaluated its utility to discern nociceptive responses to skin incision. RESULTS We developed the following hemodynamic model as calculated nociceptive response= -1+2/(1+ exp(-0.01 HR -0.02 SBP +0.17 PI)), and prospectively determined that calculated nociceptive responses to small skin incision for laparoscopic surgery were significantly lower than responses to large skin incision for laparotomy. CONCLUSIONS Our hemodynamic model using HR, SBP, and PI likely reflects nociceptive levels at skin incision during general anesthesia, and quantitatively discerned the difference in nociceptive responses to skin incision between laparoscopy and laparotomy. This model could be applicable to assess either real-time nociceptive responses or averaged nociceptive responses throughout surgery without using special equipment.

Role of Elevated Fibrinogen in Burn-Induced Mitochondrial Dysfunction: Protective Effects of Glycyrrhizin

INTRODUCTION

Skeletal muscle wasting and weakness with mitochondrial dysfunction (MD) are major pathological problems in burn injury (BI) patients. Fibrinogen levels elevated in plasma is an accepted risk factor for poor prognosis in many human diseases, and is also designated one of damage-associated molecular pattern (DAMPs) proteins. The roles of upregulated fibrinogen on muscle changes of critical illness including BI are unknown. The hypothesis tested was that BI-upregulated fibrinogen plays a pivotal role in the inflammatory responses and MD in muscles, and that DAMPs inhibitor, glycyrrhizin mitigates the muscle changes.

METHODS

After third degree BI to mice, fibrinogen levels in the plasma and at skeletal muscles were compared between BI and sham-burn (SB) mice. Fibrinogen effects on inflammatory responses and mitochondrial membrane potential (MMP) loss were analyzed in C2C12 myotubes. In addition to survival, the anti-inflammatory and mitochondrial protective effects of glycyrrhizin were tested using in vivo microscopy of skeletal muscles of BI and SB mice.

RESULTS

Fibrinogen in plasma and its extravasation to muscles significantly increased in BI versus SB mice. Fibrinogen applied to myotubes evoked inflammatory responses (increased MCP-1 and TNF-α; 32.6 and 3.9-fold, respectively) and reduced MMP; these changes were ameliorated by glycyrrhizin treatment. In vivo MMP loss and superoxide production in skeletal muscles of BI mice were significantly attenuated by glycyrrhizin treatment, together with improvement of BI survival rate.

CONCLUSIONS

Inflammatory responses and MMP loss in myotubes induced by fibrinogen were reversed by glycyrrhizin. Anti-inflammatory and mitochondrial protective effect of glycyrrhizin in vivo leads to amelioration of muscle MD and improvement of BI survival rate.

Bacterial-excreted small volatile molecule 2-aminoacetophenone induces oxidative stress and apoptosis in murine skeletal muscle

Oxidative stress induces mitochondrial dysfunction and facilitates apoptosis, tissue damage or metabolic alterations following infection. We have previously discovered that the Pseudomonas aeruginosa (PA) quorum sensing (QS)-excreted small volatile molecule, 2-aminoacetophenone (2-AA), which is produced in infected human tissue, promotes bacterial phenotypes that favor chronic infection, while also compromising muscle function and dampens the pathogen-induced innate immune response, promoting host tolerance to infection. In this study, murine whole-genome expression data have demonstrated that 2-AA affects the expression of genes involved in reactive oxygen species (ROS) homeostasis, thus producing an oxidative stress signature in skeletal muscle. The results of the present study demonstrated that the expression levels of genes involved in apoptosis signaling pathways were upregulated in the skeletal muscle of 2-AA-treated mice. To confirm the results of our transcriptome analysis, we used a novel high-resolution magic-angle-spinning (HRMAS), proton (¹H) nuclear magnetic resonance (NMR) method and observed increased levels of bisallylic methylene fatty acyl protons and vinyl protons, suggesting that 2-AA induces skeletal muscle cell apoptosis. This effect was corroborated by our results demonstrating the downregulation of mitochondrial membrane potential in vivo in response to 2-AA. The findings of the present study indicate that the bacterial infochemical, 2-AA, disrupts mitochondrial functions by inducing oxidative stress and apoptosis signaling and likely promotes skeletal muscle dysfunction, which may favor chronic/persistent infection.

[Change in Perioperative Hemostatic Function in Patients Undergoing Hepatic Resection for Primary and Metastatic Liver Cancer]

BACKGROUND

Patients undergoing primary hepatic resection often develop hemostatic dysfunction associated with cirrhosis.

METHODS

We retrospectively surveyed pre- and postoperative prothrombin time (PT) and the PT expressed as international normalized ratio (PT-INR) in 39 patients undergoing primary liver resection. We also compared PT changes between primary and metastatic cancer cases (8 cases).

RESULTS

Postoperative PT-INR was 1.40 ± 0.38, which was significantly prolonged compared to preoperative PT-INR of 1.08 ± 0.07. Preoperative PT was over 70% in all 39 patients undergoing primary liver resection, whereas postoperative PT was less than 60% in 13 of 39 patients. No significant difference was found in preoperative PT-INR between primary and metastatic cancer cases, but postoperative PT-INR was significantly prolonged in primary cancer cases.

CONCLUSIONS

Patients undergoing primary liver resection are susceptible to hemostatic dysfunction, even with preoperative PT levels within normal limits.

Comparison of the Miller Laryngoscope and Videolaryngoscope for Tracheal Intubation by Novice Doctors during Neonatal Cardiopulmonary Resuscitation: A Randomized Crossover Simulation Trial

OBJECTIVE

Recent guidelines for neonatal cardiopulmonary resuscitation emphasize the importance of adequate ventilation. In cases of failed resuscitation with positive pressure ventilation, tracheal intubation and chest compressions are recommended. The present study compared the utility of the Miller laryngoscope (Mil) and the videolaryngoscope Pentax-AWS Airway Scope (AWS; Hoya, Tokyo, Japan) with an infant or neonatal-sized Intlock (AWS-N; Pentax) during chest compressions on a neonatal manikin.

STUDY DESIGN

A total of 23 novice doctors performed tracheal intubation on a neonatal manikin using the Mil and AWS-N, with or without chest compressions.

RESULTS

In the Mil trials, all participants secured the airway without chest compressions, but nine failed with compressions (p < 0.001). In AWS-N trials, all participants succeeded regardless of whether chest compressions were performed or not. Intubation time was significantly longer with chest compressions with the Mil (p < 0.001), but not with the AWS-N. Laryngoscopy difficulty, as assessed by a visual analog scale (VAS), increased significantly with chest compressions with the Mil, but not with the AWS-N, while the VAS for tube passage through the glottis increased with compressions with the Mil, but not with the AWS-N.

CONCLUSION

The AWS-N is an effective device for endotracheal intubation during chest compressions in neonatal simulations performed by novice doctors.

A DNA aptamer to c-Met inhibits cancer cell migration

The HGF/c-Met pathway is known to play a key role in cancer metastasis. CLN0003_SL1, a 50-mer DNA aptamer that binds to the c-Met protein, was found to inhibit HGF-induced c-Met activation. This aptamer could suppress cancer cell motility in vitro.

Simulation analysis of three intubating supraglottic devices during infant chest compression

Current guidelines for pediatric cardiopulmonary resuscitation suggest that supraglottic devices are alternatives for tracheal intubation with minimal interruption of chest compression. We examined the utility of three intubating supraglottic devices, air-Q® (air-Q), Ambu® aura-i (aura-i), and i-gel® (i-gel), utilizing manikin simulation. Twenty-two novice physicians performed securing of airway on an infant manikin with the three devices. We measured the rate of success on ventilation and the insertion time with or without chest compression. Successful ventilation rate did not significantly decrease with chest compression in the three devices (without chest compression: air-Q, 21/22; aura-i, 20/22; i-gel, 20/22, during chest compression: air-Q, 20/22; aura-i, 20/22; i-gel, 18/22). The insertion time with air-Q and aura-i did not extend significantly for chest compression. In contrast, the insertion time with i-gel was significantly extended in chest compression (P < 0.05). Air-Q and aura-i are more useful for airway management during chest compression than i-gel.

Comparison of insertion of the modified i-gel airway for oral surgery with the LMA Flexible: a manikin study

We previously modified the i-gel airway to enable its use in the field of oral and maxillofacial surgery and reported its fabrication methods. In general, the standard i-gel airway is quick to insert and has a high success rate, but the modified i-gel airway has yet to be assessed for these attributes. We, therefore, set out to compare the ease of insertion of the modified i-gel airway with the LMA Flexible to investigate the usefulness of the modified i-gel airway. The study participants, who included 20 new interns with no experience using either the LMA Flexible or the modified i-gel airway, inserted each device 3 times into an intubation practice manikin. The variables measured in this study were insertion time and rate of successful insertions. Mean insertion time over 3 attempts was significantly shorter for the modified i-gel™ airway (18.9 ± 4.7 seconds) than the LMA Flexible (24.9 ± 5.1 seconds, P < .001). The rate of successful insertions as a total of all 3 attempts was significantly higher for the modified i-gel airway (56/60 times, 93.3%) than the LMA Flexible (45/60 times, 75%; P = .012). When used by an inexperienced operator, the modified i-gel™ airway is faster and has a higher success rate than the LMA Flexible, suggesting that it can be easily manipulated during insertion.

Significance of debriefing methods in simulation-based sedation training courses for medical safety improvement in Japan

Based on the American Society of Anesthesiologists' Practice Guidelines for Sedation and Analgesia by Non-Anesthesiologists (ASA-SED), a sedation training course aimed at improving medical safety was developed by the Japanese Association for Medical Simulation in 2011. This study evaluated the effect of debriefing on participants' perceptions of the essential points of the ASA-SED. A total of 38 novice doctors participated in the sedation training course during the research period. Of these doctors, 18 participated in the debriefing group, and 20 participated in non-debriefing group. Scoring of participants' guideline perceptions was conducted using an evaluation sheet (nine items, 16 points) created based on the ASA-SED. The debriefing group showed a greater perception of the ASA-SED, as reflected in the significantly higher scores on the evaluation sheet (median, 16 points) than the control group (median, 13 points; p < 0.05). No significant differences were identified before or during sedation, but the difference after sedation was significant (p < 0.05). Debriefing after sedation training courses may contribute to better perception of the ASA-SED, and may lead to enhanced attitudes toward medical safety during sedation and analgesia.

[Refinement of the simulation-based sedation training course based on sedation and analgesia guidelines for non-anesthesiologists by American Society of Anesthesiologists]

We report the refinement of the simulation-based sedation training course (SEDTC) hosted by the Japanese Association of Medical Simulation, and the drafting and development of an learning goal and instructor course. In basic airway management training, we highlighted the importance of the "call for help" and oxygen supply. In card-based simulation training sessions, we posted a picture detailing recommended amounts of oxygen and the duration of its use. We set the time of preplanning of sedation strategy in the simulation-training. Twenty-seven SEDTCs were conducted between August 2011 and March 2013 at several locations in Japan. A total of 395 medical staffs affiliated with various medical departments participated in the courses. SEDTCs may serve as a vehicle to improve the safety of sedation and analgesia.

Effects of a simulation-based sedation training course on non-anesthesiologists' attitudes toward sedation and analgesia

The purpose of this study was to conduct a survey of emergency or complication during sedation and change of attitude toward sedation by simulation-based sedation training course (SEDTC) hosted by the Japanese Association of Medical Simulation. We used a questionnaire survey to non-anesthesiologists who participated in the 1st to 13th SEDTCs from 2011 to 2012. Survey contents included emergencies or complications during sedation and impressions of the Sedation and Analgesia guidelines for non-anesthesia doctors developed by the American Society of Anesthesiologists. Of 84 non-anesthesiologists, 81 have encountered patient respiratory suppression. More than 70% non-anesthesiologists have encountered patient respiratory arrest. All non-anesthesiologists have encountered patient cardiac suppression; 20-30% of non-anesthesiologists have encountered patient anaphylaxis, asthma attack, and cardiac arrest; and all non-anesthesiologists have encountered patient vomiting and about 80% aspiration. Non-anesthesiologists largely accepted the guidelines. SEDTC attendance improved significantly 13 points of 18 important suggestions. As non-anesthesiologists experience several complications during sedation, SEDTC may be useful for the improvement of their attitude toward the safety management of sedation.

Effect of decreased fetal perfusion on placental clearance of volatile anesthetics in a dual perfused human placental cotyledon model

Placental transfer of volatile anesthetics is a critical issue in managing fetal distress during cesarean section under general anesthesia. Using dual perfused human placental cotyledons obtained from parturients undergoing elective cesarean section (n = 5), we investigated the effect of decreased fetal perfusion on placental clearance of sevoflurane and isoflurane. Keeping the maternal flow rate fixed, fetal flow rate was consecutively decreased from 3 ml/min (control perfusion) to 2 ml/min (intermediate perfusion) and to 1 ml/min (hypoperfusion). Placental transfer was assessed by the clearance of anesthetics by the placenta, defined by the ratio of anesthetic concentration in fetal vein and maternal artery, multiplied by fetal flow rate. Placental clearance was compared between different fetal perfusion states and anesthetics. Hypoperfusion resulted in a lower clearance of sevoflurane and isoflurane compared with control (P = 0.002, P < 0.001) and intermediate (P = 0.04, P = 0.018) perfusion. Clearances of sevoflurane and isoflurane were comparable during control perfusion (P = 0.93), intermediate perfusion (P = 1.00), and hypoperfusion (P = 0.88). Thus, maintenance of volatile anesthetics at a marginally low concentration may not be necessary when fetal distress is observed during emergency cesarean delivery because placental transfer of volatile anesthetics decreases with decreasing fetal perfusion.

Utility of the Aintree Intubation Catheter in fiberoptic tracheal intubation through the three types of intubating supraglottic airways: a manikin simulation study

Purpose

The purpose of this study was to examine the utility of the Aintree Intubation Catheter (AIC) with three types of supraglottic airway devices for tracheal intubation (ISGAs) using a manikin.

Methods

Participants were 21 anesthesiologists with more than 2 years of experience in clinical anesthesia. Three types of ISGAs were passed through the glottis: Fastrack-Single Use (FSU; size 4), air-Q (size 3.5), and i-gel (size 4). Participants attempted fiberoptic tracheal intubation with the ISGAs in random order. Success rate of tracheal intubation, intubation time, and collision with the glottis were recorded. Participants also evaluated the subjective difficulty of the entire intubation process and passing the tracheal tube through the glottis using a Visual Analogue Scale.

Results

The FSU required a significantly longer time for intubation compared with the other two ISGAs (p < 0.05). AIC use did not significantly improve the success rate of intubation or shorten intubation times for any of the ISGAs. However, there were significantly more collisions with the glottis without AIC use for the FSU and air-Q compared to when they were used with the AIC (FSU, p = 0.015; air-Q, p = 0.025).

Conclusion

Among the ISGAs tested, intubation took longer with the FSU, and the FSU had a higher failure rate than the other ISGAs. AIC significantly decreased the number of collisions with the FSU and air-Q. These findings suggest that the AIC is effective in reducing collisions with the tracheal tube and thus will reduce the risk of mechanical injury to the airway.

[Application of air-Q laryngeal airway and gum elastic bougie in a case of anticipated difficult. Mask ventilation and tracheal intubation in a man with morbid obesity]

A 46-year-old man was diagnosed with descending colon cancer and was planned to undergo left hemicolectomy under general anesthesia. His body mass index was 42.6 and due to his small mouth and jaw, we anticipated difficult mask ventilation and tracheal intubation. To avoid 'can't ventilate, can't intubate', we first inserted a size 3.5 air-Q laryngeal airway under moderate sedation, maintaining spontaneous ventilation. After confirming sufficient assisted ventilation, we used a bronchofiberscope to visualize placement of a gum elastic bougie in the trachea via the air-Q. Then, we replaced the air-Q with an outside diameter 8.5 mm tracheal tube. This case was a successful use of the air-Q under moderate sedation for airway management in the setting of anticipated difficult mask ventilation and tracheal intubation.

Comparison of Pentax-AWS Airwayscope, Airtraq and Miller laryngoscope for tracheal intubation by novice doctors during infant cardiopulmonary resuscitation simulation: a randomized crossover trial

Recent guidelines for infant cardiopulmonary resuscitation emphasize that all rescuers should minimize interruption of chest compressions, even for endotracheal intubation. We compared the utility of the Pentax-AWS Airway Scope (AWS) with an infant-sized Intlock (AWS-I), Airtraq laryngoscope (ATQ) and Miller laryngoscope during chest compressions on an infant manikin. Twenty-three novice doctors performed tracheal intubation on an infant manikin using the AWS-I, ATQ and Miller laryngoscope, with or without chest compressions. In Miller laryngoscope trials, one participant failed to secure the airway without chest compressions, while nine failed with compressions (P < 0.05). In ATQ trials, none of the participants failed without compressions, while six failed with compressions (P < 0.05). In AWS-I trials, all participants succeeded regardless of chest compressions. Intubation time was significantly longer with chest compressions with the Miller laryngoscope and ATQ, but not with the AWS-I. The AWS-I is an effective device for endotracheal intubation during chest compressions in infant simulations managed by novice doctors.

[A case of awake intubation using the Pentax-AWS airwayscope in a patient with a difficult airway combined with severe hemorrhagic shock]

We report a case of awake intubation in a patient with a difficult airway combined with severe hemorrhagic shock using the Pentax-AWS Airwayscope (AWS). A 65-year-old man experienced severe hemorrhagic shock due to diaphragmatic hernia after extrapleural pneumonectomy and was scheduled for emergent exploratory thoracotomy under general anesthesia. Blood pressure was maintained with dopamine-noradrenaline support, and rapid transfusion. We anticipated difficult ventilation due to a swollen face and tongue. The patient underwent awake intubation with the AWS under dexmedetomidine sedation and lidocaine spray for laryngotracheal anesthesia. The patient did not buck during intubation and hemodynamic changes were minimal.

[Anesthesia for tracheal metal stent management utilizing venovenous extracorporeal life support]

We report a successful case of metal stent replacement utilizing venovenous extracorporeal life support (VV-ECLS). A 71-year-old woman, who had previously undergone tracheal metal stent placement, encountered dyspnea associated with inversion of the stent. Metal stent replacement was planned under general anesthesia. After securing the VV-ECLS in the right and left femoral vein, anesthesia was induced with propofol and remifentanil. Metal stent replacement was conducted under rigid and flexible bronchoscope through the tracheal tube. Oxygenation and carbon dioxide excretion were achieved uneventfully. VV-ECLS was considered useful for the management of subglottic difficult airway such as complex tracheal stenosis.

Cesium-ion selective electrodes based on calix[4]arene dibenzocrown ethers

Four calix[4]arene dibenzocrown ether compounds have been prepared and evaluated as Cs(+)-selective ligands in solvent polymeric membrane electrodes. The ionophores include 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-6 1, 25,27-bis(1-alkyloxy)calix[4]arene dibenzocrown-7s 2 and 3, and 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-8 4. For an ion-selective electrode (ISE) based on 1, the linear response concentration range is 1x10(-1) to 1x10(-6) M of Cs(+). Potentiometric selectivities of ISEs based on 1-4 for Cs(+) over other alkali metal cations, alkaline earth metal cations, and NH(4)(+) have been assessed. For 1-ISE, a remarkably high Cs(+)/Na(+) selectivity was observed, the selectivity coefficient (K(Cs,Na)(Pot)) being ca. 10(-5). As the size of crown ether ring is enlarged from crown-6 (1) to crown-7 (2 and 3) to crown-8 (4), the Cs(+) selectivity over other alkali metal cations, such as Na(+) and K(+), is reduced successively. Effects of membrane composition and pH in the aqueous solution upon the electrode properties are also discussed.

[Use of the air-Q laryngeal airway and tube exchanger in a case of difficult tracheal extubation after maxillectomy]

A 79-year-old man was diagnosed with maxillary cancer and underwent total maxillectomy under general anesthesia. The oropharyngeal airway was needed for efficient mask ventilation during anesthesia induction. The maxilla was totally resected and reconstructed with skin from a femoral flap. Tracheal extubation was considered to be difficult given that mask ventilation was contraindicated due to reconstruction of the maxilla. After inserting a tube exchanger (TE) into the trachea, the tracheal tube was exchanged with an air-Q laryngeal airway through the TE. After confirming effective ventilation with the air-Q mask, the patient was awakened from anesthesia. We confirmed sufficient spontaneous breathing and no active bleeding in the pharynx. After re-inserting the TE thorough air-Q, the air-Q was removed, followed by removal of the TE. These findings suggest that the air-Q and TE were effective in a case of difficult extubation after maxillectomy.

[A case of cardiac arrests before and after emergent exploratory laparotomy for panperitonitis]

We report a case of cardiac arrest before and after emergent exploratory laparotomy for panperitonitis in an 84-year-old woman with a history of hypertension, gastric ulcer, uterine myoma and dementia. She complained of lower abdominal pain, and suffered from septic shock and DIC. The first cardiac arrest occurred after anesthesia induction. Following resuscitation, a left hemicolectomy and colostomy were performed. The second cardiac arrest occurred immediately after the operation. Cardiac arrest in this case may have been due to preexisting cardiac dysfunction enhanced by septic shock. Prompt preoperative evaluation of cardiac function is necessary for successful circulatory management during anesthesia induction for surgical patients in septic shock.

[Emergent thoracic endovascular aortic repair in a patient with hemoptysis due to bronchial fistula: a case for airway management]

Bronchial fistula due to bronchial compression is a rare complication following both open surgical and endovascular repair of thoracic aortic aneurysms. We report on the airway management for a case of emergent thoracic endovascular aortic repair (TEVAR) in a patient with left bronchial obstruction due to hemoptysis. A 68-year-old man had undergone total arch replacement 8 years before, and was preoperatively diagnosed with aortobronchial fistula in the left lung. To prevent obstruction of the right lung by rebleeding in the left bronchus, we planned to exchange the single lumen endotracheal tube placed following hemoptysis to a double lumen tube prior to the operation. With assisted spontaneous breathing, bronchoscopy performed before replacing of the endotracheal tube showed obstruction of the left bronchus with many clots. With bronchoscopic assistance, clots were removed from the left bronchus and oxygenation improved significantly. We found a blue nylon suture penetrating the bronchial wall, most likely from a previous operation. However, bronchoscopy did not disclose aortobronchial fistula. Following TEVAR, the patient was diagnosed with bronchopleural fistula induced by bronchial compression due to blood vessel prosthesis and surrounding felt strips. Cooperation from surgeons and careful airway management were required to prevent life-threatening oxygenation insufficiency.

Comparison of air-Q(®) and Soft Seal(®) laryngeal mask for airway management by novice doctors during infant chest compression: a manikin study

BACKGROUND

Recent resuscitation guidelines for infant cardiopulmonary resuscitation (CPR) emphasise that rescuers should minimise the interruption of chest compressions. To that end, supraglottic devices such as laryngeal mask airways (LMAs) are suggested as a backup for airway management during infant CPR. We therefore compared the utility of the air-Q(®) LMA (air-Q) with that of the Soft Seal(®) LMA (Soft Seal) for infant CPR in an infant manikin.

METHODS

Twenty-four novice doctors in the anaesthesia department performed insertion and ventilation with air-Q and Soft Seal on an infant manikin with or without chest compression.

RESULTS

Two doctors failed to insert the Soft Seal without chest compression, while nine failed during chest compression (P<0.05). However, only one doctor failed to insert the air-Q without chest compression, and two doctors failed during chest compression. Insertion time was not significantly increased with chest compression using either device. Insertion time during chest compression was significantly shorter for the air-Q than for the Soft Seal (P<0.05). The visual analogue scale (VAS) was used to evaluate difficulty of use (0mm (extremely easy) to 100mm (extremely difficult)). VAS scores did not change significantly by the addition of chest compression with either device; however, VAS scores during chest compression were significantly higher with Soft Seal than with the air-Q device.

CONCLUSION

We conclude that novice doctors find the air-Q easier to use than Soft Seal for emergency airway management during chest compression in infants, in an infant manikin.