A randomized comparison of three intubation techniques/tube materials for nasotracheal intubation.

PURPOSE: We sought to compare three intubation methods using different intubation techniques/tube materials for tube advancement from the nasal cavity into the oral cavity during nasotracheal intubation. METHODS: We conducted a randomized clinical trial with adult patients scheduled to undergo elective surgery requiring nasotracheal intubation for general anesthesia. Participants were randomly allocated to a polyvinyl chloride (PVC) tube group (group P), PVC tube attached to a rubber catheter group (group PR), or velvet-soft PVC tube group (group V). Tracheal intubation was then performed based on group allocation. The primary outcome was the first-attempt success rate of tube advancement into the oral cavity; secondary outcomes included the time required for tube advancement into the oral cavity, total intubation time, and the incidence of epistaxis. RESULTS: A total of 149 patients were included in the study. The first-attempt success rate in group V (90%) was significantly higher than that in group P (58%) (odds ratio, 6.5; 95% confidence interval [CI], 2.2 to 19.2), but similar to that in group PR (100%). The mean (standard deviation) time required for tube advancement into the oral cavity was significantly shorter in group V (16 [13] sec) than in group PR [40 (10) sec; 95% CI of mean difference, 17 to 30] and group P (26 [16] sec; 95% CI of mean difference, 3 to 16). Total intubation time was longest in group PR. Epistaxis occurred the least in group V. CONCLUSIONS: Among the three intubation techniques/tube materials for nasotracheal intubation, the velvet-soft PVC tube provided the highest first-attempt success rate, most expeditious advancement into the oral cavity, and lowest incidence of epistaxis. STUDY REGISTRATION: ClinicalTrials.gov (NCT04695444); first submitted 30 December 2020.

RéSUMé: OBJECTIF: Nous avons cherché à comparer trois méthodes d'intubation utilisant différentes techniques d'intubation / matériaux de sondes pour l'avancement de la sonde de la cavité nasale dans la cavité buccale pendant l'intubation nasotrachéale. MéTHODE: Des patient·es devant recevoir une intubation nasotrachéale ont été réparti·es au hasard dans un groupe avec sondes en polychlorure de vinyle (PVC) (groupe P), un groupe avec sondes en PVC attachées à un cathéter en caoutchouc (groupe PR) ou un groupe avec sondes en PVC doux comme du velours (groupe V). L'intubation trachéale a ensuite été réalisée en fonction de l'affectation du groupe. Le critère d'évaluation principal était le taux de réussite de la première tentative d'avancement de la sonde dans la cavité buccale; les critères d'évaluation secondaires comprenaient le temps nécessaire à l'avancement de la sonde dans la cavité buccale, la durée totale de l'intubation et l'incidence d'épistaxis. RéSULTATS: Au total, 149 patient·es ont été inclus·es dans l'étude. Le taux de réussite de l'intubation à la première tentative était significativement plus élevé dans le groupe V (90 %) que dans le groupe P (58 %) (rapport de cotes, 6,5; intervalle de confiance à 95 % [IC], 2,2 à 19,2), mais similaire à celui du groupe PR (100 %). Le temps moyen (écart type) nécessaire pour l'avancement de la sonde dans la cavité buccale était significativement plus court dans le groupe V (16 [13] sec) que dans le groupe PR (40 [10] sec; IC 95 % de la différence moyenne, 17 à 30) et dans le groupe P (26 [16] sec; IC 95 % de la différence moyenne, 3 à 16). La durée totale d'intubation était la plus longue dans le groupe PR. C'est dans le groupe V que l'épistaxis a été la moins fréquente. CONCLUSION: Parmi les trois techniques d'intubation/matériaux de sonde pour l'intubation nasotrachéale, le tube en PVC doux comme du velours a fourni le taux de réussite de première tentative le plus élevé, l'avancement le plus rapide dans la cavité buccale et l'incidence d'épistaxis la plus faible. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT04695444); première soumission le 30 décembre 2020.

Utility of oxygen insufflation through working channel during fiberoptic intubation in apneic patients: a prospective randomized controlled study.

BACKGROUND: Airway management is a part of routine anesthetic procedures; however, serious complications, including hypoxia and death, are known to occur in cases of difficult airways. Therefore, alternative techniques such as fiberoptic bronchoscope-assisted intubation (FOB intubation) should be considered, although this method requires more time and offers a limited visual field than does intubation with a direct laryngoscope. Oxygen insufflation through the working channel during FOB intubation could minimize the risk of desaturation and improve the visual field. Therefore, the aim of this prospective randomized controlled study was to evaluate the utility and safety of oxygen insufflation through the working channel during FOB intubation in apneic patients. METHODS: Thirty-six patients were randomly allocated to an N group (no oxygen insufflation) or an O group (oxygen insufflation). After preoxygenation, FOB intubation was performed with (O group) or without (N group) oxygen insufflation in apneic patients. The primary outcome was the velocity of decrease in the partial pressure of oxygen (PaO2) during FOB intubation (VPaO2, mmHg/sec) defined as the difference of PaO2 before and after intubation divided by the time to intubation. The secondary outcomes included the success rate for FOB intubation, time to intubation, visual field during FOB intubation, findings of arterial blood gas analysis, and occurrence of FOB intubation-related complications. RESULTS: We found that VPaO2 was significantly greater in the N group than in the O group (1.0 ± 0.4 vs. 0.4 ± 0.4; p < 0.001), while the visual field was similar between groups. There were no significant intergroup differences in the secondary outcomes. CONCLUSIONS: These findings suggest that oxygen insufflation through the working channel during FOB intubation aids in extending the apneic window during the procedure. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02625194 , registered at December 9, 2015.

Efficacy of Single-Dose Dexmedetomidine Combined with Low-Dose Remifentanil Infusion for Cough Suppression Compared to High-Dose Remifentanil Infusion: A Randomized, Controlled, Non-Inferiority Trial.

Background: Combination of dexmedetomidine and opioid may be an alternative to high-dose opioid in attenuating cough during emergence from anesthesia, while also reducing the adverse effects of high-dose opioid. We tested the hypothesis that a single-dose of dexmedetomidine combined with low-dose remifentanil infusion during emergence would not be inferior to high-dose remifentanil infusion alone in attenuating cough after thyroidectomy. Methods: One hundred sixty-nine patients undergoing thyroidectomy were enrolled and randomized in a 1:1 ratio into group DR or group R. Each patient received an infusion of dexmedetomidine (0.5 µg/kg) and low-dose remifentanil infusion of effect-site concentration (Ce) at 1 ng/mL or normal saline and high-dose remifentanil infusion of Ce at 2 ng/mL for 10 min at the end of surgery. Remifentanil was maintained until tracheal extubation. Primary endpoint was the severity of coughing, which was assessed for non-inferiority using a four-point scale at the time of extubation. For comparison of coughing incidence during emergence, coughing grade was also measured at three times: before extubation, at extubation, and after extubation. Time to awakening, hemodynamic and respiratory profile, pain, and postoperative nausea and vomiting were also evaluated for superiority. Results: The 95% confidence intervals for differences in cough grade during tracheal extubation were <0.9, indicating non-inferiority of the single dose of dexmedetomidine combined with low-dose remifentanil infusion. The incidence of coughing was similar in the two groups. Hemodynamic changes during tracheal extubation were attenuated, but emergence from anesthesia was delayed, in group DR. Use of rescue antiemetic was similar in both groups, but the incidence of vomiting was less in group DR. Conclusion: A single-dose of dexmedetomidine (0.5 µg/kg) combined with low-dose remifentanil infusion at 1 ng/mL of Ce during emergence from sevoflurane-remifentanil anesthesia was not inferior to high-dose remifentanil infusion alone at 2 ng/mL of Ce with regard to suppressing cough.

Comparison of the efficacy of dexmedetomidine plus fentanyl patient-controlled analgesia with fentanyl patient-controlled analgesia for pain control in uterine artery embolization for symptomatic fibroid tumors or adenomyosis: a prospective, randomized study.

PURPOSE: To investigate whether dexmedetomidine infusion could reduce opioid consumption and opioid-related side effects after uterine artery embolization (UAE). MATERIALS AND METHODS: Fifty patients undergoing UAE for symptomatic leiomyomas or adenomyosis were randomized into two groups. In 25 patients, dexmedetomidine infusion was started at 0.2 µg/kg/h at 30 minutes before the procedure, followed by 0.4 µg/kg/h for 6 hours after the procedure. In another 25 patients (control group), volume-matched normal saline solution was administered. Both groups received fentanyl-based intravenous patient-controlled analgesia (PCA; fentanyl 10 µg/h with a bolus dose of 20 µg) during the 24 hours after the procedure. Nonspherical polyvinyl alcohol particles were used. Pain scores, fentanyl consumption, need for additional analgesics, and side effects were assessed for 24 hours after UAE. RESULTS: Compared with the control group, patients in the dexmedetomidine group required 28% less PCA fentanyl during the 24 hours after UAE (P = .006). Numeric rating scale scores for pain (5.0±2.4 vs 7.0±2.2; P = .026) and the need for additional analgesics (two of 25 vs 17 of 25; P<.001) were lower in the dexmedetomidine group than in the control group during the first 1 hour after UAE. The incidence and severity of nausea and vomiting during the 24 hours after UAE were lower in the dexmedetomidine group than in the control group (P < .05). CONCLUSIONS: The addition of dexmedetomidine infusion to fentanyl PCA provides better analgesia, fentanyl-sparing effect, and less nausea and vomiting, without significant hemodynamic instability.

Effects of flashlight guidance on chest compression performance in cardiopulmonary resuscitation in a noisy environment.

BACKGROUND: In real cardiopulmonary resuscitation (CPR), noise can arise from instructional voices and environmental sounds in places such as a battlefield and industrial and high-traffic areas. A feedback device using a flashing light was designed to overcome noise-induced stimulus saturation during CPR. This study was conducted to determine whether 'flashlight' guidance influences CPR performance in a simulated noisy setting. MATERIALS AND METHODS: We recruited 30 senior medical students with no previous experience of using flashlight-guided CPR to participate in this prospective, simulation-based, crossover study. The experiment was conducted in a simulated noisy situation using a cardiac arrest model without ventilation. Noise such as patrol car and fire engine sirens was artificially generated. The flashlight guidance device emitted light pulses at the rate of 100 flashes/min. Participants also received instructions to achieve the desired rate of 100 compressions/min. CPR performances were recorded with a Resusci Anne mannequin with a computer skill-reporting system. RESULTS: There were significant differences between the control and flashlight groups in mean compression rate (MCR), MCR/min and visual analogue scale. However, there were no significant differences in correct compression depth, mean compression depth, correct hand position, and correctly released compression. The flashlight group constantly maintained the pace at the desired 100 compressions/min. Furthermore, the flashlight group had a tendency to keep the MCR constant, whereas the control group had a tendency to decrease it after 60 s. CONCLUSION: Flashlight-guided CPR is particularly advantageous for maintaining a desired MCR during hands-only CPR in noisy environments, where metronome pacing might not be clearly heard.

Effect of analgesia nociception index monitor-based nociception control on perioperative stress responses during laparoscopic surgery in Trendelenburg position: a randomized controlled trial.

Introduction: The analgesia nociception index (ANI) monitor is a nociception monitoring device based on heart rate variability. We aimed to determine the effect of ANI monitor-based intraoperative nociception control on the perioperative stress response during laparoscopic surgery in the Trendelenburg position. Methods: Altogether, 72 female patients who underwent total laparoscopic hysterectomy were randomized to either the control or ANI group. Intraoperative nociception was controlled by remifentanil administration in a conventional manner (based on blood pressure and heart rate) in the control group and by ANI monitoring in the ANI group. Perioperative stress responses were estimated by measuring the levels of serum catecholamines and catabolic stress hormones at three timepoints: after loss of consciousness, at the end of surgery, and 1 h after the end of surgery. Results: The serum cortisol level at the end of surgery was significantly higher in the ANI group than in the control group (p < 0.001), although more remifentanil was administered in the ANI group than in the control group (p < 0.001). Changes in the other estimators' levels were comparable between groups during the perioperative period. The hemodynamic profiles during surgery were also significantly different between the two groups. Phenylephrine use to treat hypotension was more common in the ANI group than in the control group (p = 0.005). However, postoperative clinical outcomes such as pain and nausea/vomiting did not differ between groups. Conclusion: ANI monitor-based nociception control in laparoscopic surgery in the Trendelenburg position did not improve perioperative stress responses, intraoperative opioid consumption, or postoperative clinical outcomes.Clinical trial registration: ClinicalTrials.gov (NCT04343638).

Effect of caudal block on sevoflurane requirement for lower limb surgery in children with cerebral palsy.

BACKGROUND: Caudal block is a widely used technique for providing perioperative pain management in children. In this randomized double-blinded study, we evaluated the effects of preoperative caudal block on sevoflurane requirements in children with cerebral palsy (CP) undergoing lower limb surgery while bispectral index (BIS) values were maintained between 45 and 55. METHODS: 52 children undergoing Achilles-tendon lengthening were randomized to receive combined general-caudal anesthesia (caudal group, n = 27) or general anesthesia alone (control group, n = 25). Caudal block was performed with a single dose of 0.7 ml·kg(-1) of 1.0% lidocaine containing epinephrine at 5 µg·ml(-1). The control group received no preoperative caudal block. The endtidal sevoflurane concentrations (ET(sev)) were adjusted every minute to maintain the BIS values between 45 and 55. RESULTS: The ET(sev) required to maintain the BIS values were not significantly different between the control and caudal groups after induction of anesthesia [2.1 (0.2) vs 2.2 (0.4); P = 0.773]. However, significantly higher ET(sev) was observed in the control group before surgical incision [2.0 (0.2) vs 1.8 (0.3); P = 0.013] and during the first 20 min after surgical incision [2.2 (0.3) vs 1.4 (0.3); P < 0.001]. There was no significant difference in BIS values between the control and caudal groups throughout the study period (P > 0.05). In the caudal group, the caudal block was successful in 25 of 27 (92.6%) patients. CONCLUSIONS: Caudal block effectively reduced sevoflurane requirements by 36% compared to general anesthesia alone in children with CP undergoing lower limb surgery while BIS values were maintained between 45 and 55.

Equal Ratio Ventilation Reduces Blood Loss During Posterior Lumbar Interbody Fusion Surgery.

STUDY DESIGN: A prospective randomized double-blinded study. OBJECTIVE: The aim of this study was to compare the effect of two different ventilator modes (inspiratory to expiratory ratio [I:E ratio] of 1:1 and 1:2) on intraoperative surgical bleeding in patients undergoing posterior lumbar interbody fusion (PLIF) surgery. SUMMARY OF BACKGROUND DATA: During PLIF surgery, a considerable amount of blood loss is anticipated. In the prone position, engorgement of the vertebral vein increases surgical bleeding. We hypothesized that equal ratio ventilation (ERV) with I:E ratio of 1:1 would lower peak inspiratory pressure (PIP) in the prone position and consequentially decrease surgical bleeding. METHODS: Twenty-eight patients were randomly assigned to receive either ERV (ERV group, n = 14) or conventional ventilation with I:E ratio of 1:2 (control group, n = 14). Hemodynamic and respiratory parameters were measured at 5 minutes after anesthesia induction, at 5 minutes after the prone position, at the time of skin closure, and at 5 minutes after turning to the supine position. RESULTS: The amount of intraoperative surgical bleeding in the ERV group was significantly less than that in the control group (975.7 ±â€Š349.9 mL vs. 1757.1 ±â€Š1172.7 mL, P = 0.030). Among other hemodynamic and respiratory parameters, PIP and plateau inspiratory pressure (Pplat) were significantly lower and dynamic lung compliance (Cdyn) was significantly higher in the ERV group than those of the control group throughout the study period, respectively (all P < 0.05). CONCLUSION: Compared to conventional ratio ventilation, ERV provided lower PIP and reduced intraoperative surgical blood loss in patients undergoing PLIF surgery.Level of Evidence: 2.

The displacement of the tracheal tube during robot-assisted radical prostatectomy.

BACKGROUND AND OBJECTIVE: Robot-assisted prostatectomy requires pneumoperitoneum in a steep Trendelenburg position, which may induce endobronchial intubation or accidental extubation. The aim of the study was to evaluate the effect of pneumoperitoneum in 30 degrees Trendelenburg position on the displacement of the tracheal tube and to measure the changes in trachea length using fiberoptic bronchoscope. METHODS: Thirty male patients scheduled for robot-assisted radical prostatectomy were enrolled. After induction of general anaesthesia, the distance between the vocal cords and the tracheal tube tip (DeltaVE), between the tracheal tube tip and the carina (DeltaEC) and between the vocal cords and the carina (DeltaVC) was measured using a fiberoptic bronchoscope before and 10 min after pneumoperitoneum in neutral position (T1 and T2, respectively), and 2 h after pneumoperitoneum in 30 degrees Trendelenburg position (T3). RESULTS: The DeltaVC and DeltaEC decreased significantly 10 min after pneumoperitoneum in neutral position (T2) and 2 h after pneumoperitoneum in Trendelenburg position (T3) compared with those before pneumoperitoneum in neutral position (T1) (all P < 0.001). The changes in DeltaVE were not statistically significant. CONCLUSION: The confirmation of the tracheal tube position is recommended after pneumoperitoneum in steep Trendelenburg position during robot-assisted prostatectomy because the displacement of the tracheal tube may result in endobronchial intubation due to shortening of the carina-to-tube tip distance.

The usefulness of the laryngeal mask airway Fastrach for laryngeal surgery.

BACKGROUND AND OBJECTIVE: Suspension laryngoscopy under general anaesthesia with a tracheal tube has been widely used for laryngeal microsurgery, but it has some limitations such as intense cardiovascular stimulation during anaesthesia of short duration, occasionally a poor surgical field, and the possibility of a mass being hampered by the tracheal tube. The aim of this study was to compare the usefulness of the laryngeal mask airway (LMA) Fastrach and fibreoptic bronchoscope with a conventional suspension laryngoscope in laryngeal microsurgery. METHODS: Forty patients scheduled for laryngeal microsurgery were enrolled in this prospective randomized study consecutively. After general anaesthesia was induced, laryngeal microsurgery was performed with a fibreoptic bronchoscope through the LMA Fastrach or conventional suspension laryngoscope. The best view of the surgical field, evaluated by percentage of glottic opening score, was obtained by the up-down manipulations of the LMA Fastrach or repositioning the suspension laryngoscope. Blood pressure and heart rate changes at the baseline, preinsertion, and postinsertion were recorded. RESULTS: Percentage of glottic opening score of the LMA Fastrach group was 100 and that of the suspension laryngoscope group was 80 (P < 0.05). The LMA Fastrach insertion was performed without remarkable systolic or diastolic blood pressure or heart rate changes, but systolic, diastolic blood pressure or heart rate were increased after intubation in the suspension laryngoscope group. CONCLUSION: The LMA Fastrach during fibreoptic bronchoscope-guided laryngeal surgery provided a good surgical field and haemodynamic stability without additional risk compared with the conventional suspension laryngoscope.

Optimal conditions for Laryngeal Mask Airway insertion in children can be determined by the trapezius squeezing test.

STUDY OBJECTIVE: To evaluate the trapezius squeezing test as a criterion of adequate anesthetic depth for Laryngeal Mask Airway (LMA) insertion in children without neuromuscular blocking agents. DESIGN: Prospective, randomized clinical trial. SETTING: Operating room of a university hospital. PATIENTS: 45 ASA physical status I and II children, aged one to 6 years, undergoing minor surgical procedures. INTERVENTIONS: An LMA was inserted in each child after the trapezius squeezing test turned to be negative. MEASUREMENTS: Presence of coughing, gagging, gross purposeful movements, breath holding, laryngospasm, or desaturation during or within one minute of LMA insertion were recorded. Elapsed time of LMA insertion, end-tidal sevoflurane concentration, blood pressure, and heart rate values were also noted. MAIN RESULTS: LMA insertion was successful in 41 patients. Elapsed time to complete insertion was 5.7 +/- 1.9 minutes, and end-tidal sevoflurane concentration was 3.6 +/- 1.1 vol%. No marked hemodynamic changes occurred in any child. CONCLUSIONS: The trapezius squeezing test is a reliable clinical indicator to assess adequate anesthetic depth for LMA insertion in children without neuromuscular blocking agents.

Nicardipine Effects on Renal Function During Spine Surgery.

STUDY DESIGN: Single-center, prospective, randomized, and single-blinded clinical trial was conducted in patients (n=64) undergoing anterior or posterior spinal interbody fusion. OBJECTIVE: To investigate the renal protective effect of nicardipine during deliberate hypotension for spine surgery by measuring creatinine clearance (Ccr), serum cystatin C, urine output, and fractional excretion of sodium (FENa). SUMMARY OF BACKGROUND DATA: Deliberate hypotension during spine surgery may result in ischemic tissue damage of the kidney. Nicardipine is reported to dilate the renal artery and increase glomerular filtration rate. Previous studies reported the renal protective effect of nicardipine during cardiac surgery under cardiopulmonary bypass and robot-assisted laparoscopic surgery. MATERIALS AND METHODS: Patients were randomized to receive nicardipine (nicardipine group, n=32) or normal saline (control group, n=32). Deliberate hypotension of mean arterial pressure at 50-65 mm Hg was maintained during surgery. Ccr, serum cystatin C, urine output, and FENa were measured before surgery, after surgery, and postoperative day 1 (POD1). The RIFLE (risk, injury, failure, loss, and end stage renal disease) criteria of the patients were evaluated. RESULTS: In the nicardipine group, Ccr at POD1 was increased compared with that after surgery. In both groups, serum cystatin C at POD1 was decreased compared with that before surgery and urine output at POD1 was decreased compared with that after surgery. FENa at POD1 in the control group was higher than that in the nicardipine group and was increased compared with that after surgery. Using RIFLE criteria, 6 patients in the control group and 2 patients in the nicardipine group were classified as having acute kidney injury. CONCLUSIONS: Nicardipine increased Ccr and attenuated the increase in FENa at POD1 in patients undergoing spine surgery under deliberate hypotension.

Liquid heparin anticoagulant produces more negative bias in the determination of ionized magnesium than ionized calcium.

The ionized calcium level in blood is known to be falsely decreased when self-prepared liquid heparin anticoagulant is used, due to dilution and binding effects. The effect of liquid heparin on the determination of ionized magnesium is not as well understood. We compared the effect of liquid sodium heparin on the determination of ionized calcium and magnesium in 44 clinical samples using two types of user-prepared heparin syringes which differed in the amount of residual heparin from the BD Preset reference syringe. With the type 1 syringe, the liquid heparin was expelled once or twice such that some heparin could be left in the dead space at the syringe hub, while the liquid sodium heparin was thoroughly expelled from the type 2 syringe. The ionized magnesium levels obtained with the type 1 syringe were significantly lower than the reference value (by 0.068 mmol/L) (p < 0.0001), while the value obtained with the type 2 syringe differed less from the reference, by only 0.014 mmol/L (p < 0.0001). The heparin binding effect resulted in more negative bias in ionized magnesium (- 0.026 +/- 0.032 mmol/L) than in ionized calcium (- 0.009 +/- 0.042 mmol/L, p < 0.0001). In conclusion, we recommend using lyophilized, calcium-balanced, heparinized syringes for the determination of ionized magnesium and ionized calcium due to the increased negative bias in ionized magnesium determinations. When user-prepared syringes are used, the thorough evacuation of heparin solution should be strictly prescribed.

Does the tibial and sural nerve transection model represent sympathetically independent pain?

Neuropathic pain can be divided into sympathetically maintained pain (SMP) and sympathetically independent pain (SIP). Rats with tibial and sural nerve transection (TST) produce neuropathic pain behaviors, including spontaneous pain, tactile allodynia, and cold allodynia. The present study was undertaken to examine whether rats with TST would represent SMP- or SIP-dominant neuropathic pain by lumbar surgical sympathectomy. The TST model was generated by transecting the tibial and sural nerves, leaving the common peroneal nerve intact. Animals were divided into the sympathectomy group and the sham group. For the sympathectomy group, the sympathetic chain was removed bilaterally from L2 to L6 one week after nerve transection. The success of the sympathectomy was verified by measuring skin temperature on the hind paw and by infra red thermography. Tactile allodynia was assessed using von Frey filaments, and cold allodynia was assessed using acetone drops. A majority of the rats exhibited withdrawal behaviors in response to tactile and cold stimulations after nerve stimulation. Neither tactile allodynia nor cold allodynia improved after successful sympathectomy, and there were no differences in the threshold of tactile and cold allodynia between the sympathectomy and sham groups. Tactile allodynia and cold allodynia in the neuropathic pain model of TST are not dependent on the sympathetic nervous system, and this model can be used to investigate SIP syndromes.

Incidence and risk factors of postoperative nausea and vomiting in patients with fentanyl-based intravenous patient-controlled analgesia and single antiemetic prophylaxis.

PURPOSE: We evaluated the incidence and risk factors of postoperative nausea and vomiting (PONV) in patients with fentanyl-based intravenous patient-controlled analgesia (IV-PCA) and single antiemetic prophylaxis of 5-hydroxytryptamine type 3 (5 HT3)-receptor antagonist after the general anesthesia. MATERIALS AND METHODS: In this retrospective study, incidence and risk factors for PONV were evaluated with fentanyl IV-PCA during postoperative 48 hours after various surgeries. RESULTS: Four hundred-forty patients (23%) of 1878 had showed PONV. PCA was discontinued temporarily in 268 patients (14%), mostly due to PONV (88% of 268 patients). In multivariate analysis, female, non-smoker, history of motion sickness or PONV, long duration of anesthesia (>180 min), use of desflurane and intraoperative remifentanil infusion were independent risk factors for PONV. If one, two, three, four, five, or six of these risk factors were present, the incidences of PONV were 18%, 19%, 22%, 31%, 42%, or 50%. Laparoscopic surgery and higher dose of fentanyl were not risk factors for PONV. CONCLUSION: Despite antiemetic prophylaxis with 5 HT3-receptor antagonist, 23% of patients with fentanyl-based IV-PCA after general anesthesia showed PONV. Long duration of anesthesia and use of desflurane were identified as risk factors, in addition to risk factors of Apfel's score (female, non-smoker, history of motion sickness or PONV). Also, intraoperative remifentanil infusion was risk factor independent of postoperative opioid use. As the incidence of PONV was up to 50% according to the number of risk factors, risk-adapted, multimodal or combination therapy should be applied.

Medical simulation is needed in anesthesia training to achieve patient's safety.

Many medical schools and hospitals throughout the world are equipped with a simulation center for the purpose of training anesthesiologists to perform both technical and non-technical skills. Because induction, maintenance, and emergence of general anesthesia are critical to patient welfare, various simulation mannequins and tools are utilized for the purpose of training anesthesiologists for safer patient care. Traditionally, anesthesia residency training mostly consisted of didactic lectures and observations. After completion of "traditional" training, anesthesia residents were allowed to perform procedures on patients under supervision. However, simulation would be a more effective training tool for which to teach anesthesiologists the skills necessary to perform invasive procedures, such as endotracheal intubation, central venous catheter insertion, and epidural catheter insertion. Recently, non-technical skills, such as the Anesthesia Non-Technical Skills developed by anesthesiologists from Aberdeen University, have been emphasized as an important training resource. Technical skills and non-technical skills can be learned by anesthesiology residents through a standardized and organized simulation program. Such programs would be beneficial in training anesthesia residents to work efficiently as a team in the operation room.

Increase in airway pressure resulting from prone position patient placing may predict intraoperative surgical blood loss.

STUDY DESIGN: Prospective study on intraoperative blood loss during lumbar spine surgery. OBJECTIVE: To evaluate the relationship between airway pressure change due to the patient's prone position and intraoperative blood loss during lumbar spine surgery. SUMMARY OF BACKGROUND DATA: A prone position may increase abdominal pressure. Changes in abdominal pressure may influence airway pressure and cause intraoperative blood loss as a result of epidural venous congestion. METHODS: Patients undergoing lumbar spine surgery were placed in a prone position after the administration of general anesthesia. Peak airway pressure, plateau pressure, mean blood pressure, and heart rate were measured 5 minutes after anesthesia induction and 15 minutes after being placed in a prone position. Intraoperative blood loss was measured at the end of surgery. RESULTS: Mean peak airway pressure was 13.7 ± 1.8 mm Hg while in a supine position and increased to 15.1 ± 2.5 mm Hg after placement in the prone position (P = 0.002). Plateau pressure was 12.6 ± 2.5 mm Hg while in a supine position and increased to 14.1 ± 1.9 mm Hg after placement in a prone position (P = 0.0002). Intraoperative blood loss was correlated with peak (R2 = 0.405) and plateau (R2 = 0.489) airway pressure changes. CONCLUSION: Increase in airway pressure resulting from placement into a prone position may predict intraoperative surgical blood loss.

Effect-site concentration of remifentanil to prevent cough after laryngomicrosurgery.

OBJECTIVES/HYPOTHESIS: The aim of this study was to discover the optimal effect-site concentration of remifentanil for cough prevention that does not delay awakening or cause respiratory depression during emergence from anesthesia with propofol and remifentanil in laryngomicrosurgery patients. STUDY DESIGN: Prospective, randomized, controlled trial. METHODS: One hundred five patients were randomly assigned to maintain an effect-site concentration (Ce) of remifentanil at a predetermined value of 1 (R1), 1.5 (R1.5), and 2 (R2) ng/mL during emergence. The incidence and grade (0, no coughing; 1, single cough; 2, more than one episode of nonsustained coughing; 3, sustained and repetitive coughing with head lift) of cough, emergence time, blood pressure (MAP), heart rate (HR), spontaneous respiratory rate, oxygen saturation, and postoperative nausea and vomiting (PONV) were recorded during emergence and recovery. RESULTS: The total number of patients with coughing during emergence was lower in groups R1.5 and R2 than in group R1. The cough grade during tracheal extubation was lower in groups R1.5 and R2 than in group R1. In group R2, emergence time was longer and postanesthesia care unit score was lower than in groups R1 and R1.5. Also in group R2, transient hypoventilation and PONV were more frequent compared to group R1. There were no differences in MAP and HR among the three groups during emergence and recovery. CONCLUSIONS: Maintenance of remifentanil at Ce 1.5 and 2 ng/mL suppressed coughing without serious adverse events during emergence from anesthesia with propofol and remifentanil in patients undergoing laryngomicrosurgery.

Stress-induced cardiomyopathy after negative pressure pulmonary edema during emergence from anesthesia -A case report-.

Stress-induced cardiomyopathy (SICM) presenting as an acute myocardial dysfunction is characterized by transient left ventricular wall motion abnormality, which has been known to be associated with excessive catecholamine production caused due to various types of stress. Sympathetic hyperactivity is common during the perioperative period, and reports of SICM occurring during this period have actually increased. We present a case of SICM following negative pressure pulmonary edema due to upper airway obstruction during emergence from anesthesia. Excessive catecholamine release in response to respiratory difficulty could have been the underlying inciting factor.

Comparison of the trapezius squeezing test and jaw thrust as indicators for laryngeal mask airway insertion in adults.

BACKGROUND: The purpose of this study was to compare the effectiveness of the trapezius squeezing test with that of the jaw thrust maneuver as clinical indicators of adequate conditions for laryngeal mask airway (LMA) insertion in adults under sevoflurane anesthesia. METHODS: One hundred adult patients of ASA physical status 1 or 2 undergoing minor surgical procedures were randomly allocated to the T (trapezius squeezing, n = 50) group or the J (jaw thrust, n = 50) group. The LMA was inserted immediately after the loss of response to trapezius squeezing or jaw thrust. Successful and unsuccessful attempts were recorded. An unsuccessful attempt was defined as the occurrence of coughing, gagging, gross purposeful movements, breath-holding, laryngospasm, or an SpO(2) < 90% during LMA insertion. Insertion time, end-tidal sevoflurane concentration, mean arterial pressure, and heart rate were recorded. RESULTS: The incidence of successful attempts was significantly higher in the T than in the J group (48/50 vs. 36/50, respectively). CONCLUSIONS: The trapezius squeezing test is a superior indicator of an adequate condition for LMA insertion compared to the jaw thrust maneuver in adults under sevoflurane anesthesia.