Jiwon An

Venous air embolism during total laparoscopic hysterectomy: comparison to total abdominal hysterectomy.

Background:Total laparoscopic hysterectomy (TLH) has become a widely accepted alternative to total abdominal hysterectomy (TAH). The aim of this study was to compare the incidence and grade of venous air embolism (VAE) in TLH to those in TAH using transesophageal echocardiography. Methods:Eighty-two American Society of Anesthesiologists physical status I patients scheduled for either TLH or TAH were enrolled. After induction of general anesthesia, a multiplane transesophageal echocardiography probe was inserted. The midesophageal four-chamber or bicaval view was continuously monitored. An independent transesophageal echocardiography–certified anesthesiologist graded VAE. Results:All patients undergoing TLH showed VAE, and 37.5% of patients had VAE grade higher than III. Fifteen percent of patients undergoing TAH showed VAE, and all of them were grade I. No patient in this study showed hemodynamic instability or electrocardiogram changes at the time of VAE occurrence. Most instances of VAE during TLH occurred during transection of the round ligament and dissection of the broad ligament. Conclusion:The incidence of VAE in patients undergoing TLH was 100%. VAE grade in TLH was higher compared to that in TAH, especially during transection of the round ligament and dissection of the broad ligament. Although the hemodynamic instability associated with VAE during TLH was not observed in this study, anesthesiologists must be vigilant for detection of VAE during TLH.

Comparison of volume-controlled and pressure-controlled ventilation in steep Trendelenburg position for robot-assisted laparoscopic radical prostatectomy ☆

STUDY OBJECTIVE To compare the effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) on respiratory mechanics and hemodynamics in steep Trendelenburg position. DESIGN Prospective, randomized clinical trial. SETTING University hospital. PATIENTS 34 ASA physical status 1 and 2 patients undergoing RLRP. INTERVENTIONS Patients were randomly allocated to either the VCV (n = 17) or the PCV group (n = 17). After induction of anesthesia, each patients lungs were ventilated in constant-flow VCV mode with 50% O(2) and tidal volume of 8 mL/kg; a pulmonary artery catheter was then inserted. After establishment of 30° Trendelenburg position and pneumoperitoneum, VCV mode was switched to PCV mode in the PCV group. MEASUREMENTS Respiratory and hemodynamic variables were measured at baseline supine position (T1), post-Trendelenburg and pneumoperitoneum 60 minutes (T2) and 120 minutes (T3), and return to baseline after skin closure (T4). MAIN RESULTS The PCV group had lower peak airway pressure (AP(peak)) and greater dynamic compliance (C(dyn)) than the VCV group at T2 and T3 (P < 0.05). However, no other variables differed between the groups. Pulmonary arterial pressure and central venous pressure increased at T2 and T3 (P < 0.05). Cardiac output and right ventricular ejection fraction were unchanged in both groups. CONCLUSIONS PCV offered greater C(dyn) and lower AP(peak) than VCV, but no advantages over VCV in respiratory mechanics or hemodynamics.

Site symmetry of Er3+ in In0.5Ga0.5P

The site and site symmetry of Er3+ in LPE grown In0.5Ga0.5P have been investigated for the first time through Raman and polarized luminescence spectroscopic techniques. The Er3+ site was found to be ErIn in In0.5Ga0.5P. The site symmetry of Er3+ in In0.5Ga0.5P was positively confirmed asC2v.

Ultrasonographic assessment of optic nerve sheath diameter during pediatric laparoscopy.

This study investigated the extent of the raised intracranial pressure resulting from carbon dioxide (CO2) pneumoperitoneum by ultrasonographically measuring optic nerve sheath diameter (ONSD) in children undergoing laparoscopic surgery. Twenty-five children aged less than 9 y (53.1 ± 23.3 mo, mean ± standard deviation) and scheduled for an elective laparoscopic surgery participated. ONSD was assessed using ocular ultrasonography 10 min after induction of anesthesia (T0), 10 min after induction of CO2 pneumoperitoneum at 10 mm Hg intra-abdominal pressure (T1) and in an anesthetized state without CO2 pneumoperitoneum at the conclusion of the surgery (T2). During CO2 pneumoperitoneum, ONSD increased significantly compared with ONSD after anesthesia induction (T0: 4.3 ± 0.3 mm, T1: 4.6 ± 0.3 mm, p < 0.05). In all enrolled patients, any neurologic complications were not observed during the intra-operative or post-operative period. In children undergoing laparoscopic surgery, an increase in ONSD was ascertained during CO2 pneumoperitoneum, and thus the corresponding increase in intracranial pressure could be predicted.

Laryngeal Mask Airway Insertion in Adults: Comparison between Fully Deflated and Partially Inflated Technique

Purpose The laryngeal mask airway (LMA) is a supraglottic airway device designed to seal around the laryngeal inlet. A controlled study was designed to compare the effectiveness and complications in inserting the LMA when the cuff is fully deflated and partially inflated. Materials and Methods American Society of Anesthesiologists physical status I or II 172 female patients scheduled for gynecologic procedures were included in this study. Patients were randomly allocated into one of the two groups; fully deflated (n=86) and partially inflated group (n=86). A size #4 LMA was inserted. The number of attempts, time taken for successful insertion, grade of leak, grade of fiberoptic view, and complications were evaluated. Results All 172 patients completed the study protocol. The number of attempts, time taken for successful insertion, and grade of leak were not significantly different between the two groups. The grade of fiberoptic view and complications were lower in the fully deflated group. Conclusion The fully deflated method is more accurate and safe because of better fiberoptic view and lesser complications than the partially inflated group.

Comparison of the i-gel and other supraglottic airways in adult manikin studies: Systematic review and meta-analysis

Background: The i-gel has a gel-like cuff composed of thermoplastic elastomer that does not require cuff inflation. As the elimination of cuff inflation may shorten insertion time, the i-gel might be a useful tool in emergency situations requiring prompt airway care. This systematic review and meta-analysis of previous adult manikin studies for inexperienced personnel was performed to compare the i-gel with other supraglottic airways. Methods: We searched PubMed, the Cochrane Library, and EMBASE for eligible randomized controlled trials (RCTs) published before June 2015, including with a crossover design, using the following search terms: “i-gel,” “igel,” “simulation,” “manikin,” “manikins,” “mannequin,” and “mannequins.” The primary outcomes of this review were device insertion time and the first-attempt success rate of insertion. Results: A total of 14 RCTs were included. At the initial assessment without difficult circumstances, the i-gel had a significantly shorter insertion time than the LMA Classic, LMA Fastrach, LMA Proseal, LMA Unique, laryngeal tube, Combitube, and EasyTube. However, a faster insertion time of the i-gel was not observed in comparisons with the LMA Supreme, aura-i, and air-Q. In addition, the i-gel did not show the better results for the insertion success rate when compared to other devices. Conclusion: The findings of this meta-analysis indicated that inexperienced volunteers placed the i-gel more rapidly than other supraglottic airways with the exception of the LMA Supreme, aura-i, and air-Q in manikin studies. However, the quicker insertion time is clinically not relevant. The unapparent advantage regarding the insertion success rate and the inherent limitations of the simulation setting indicated that additional evidence is necessary to confirm these advantages of the i-gel in an emergency setting.

Incidence of Venous Air Embolism during Myomectomy: The Effect of Patient Position

Purpose Venous air embolism (VAE) is characterized by the entrainment of air or exogenous gases from broken venous vasculature into the central venous system. No study exists regarding the effect of patient positioning on the incidence of VAE during abdominal myomectomy. The purpose of this study was to assess the incidence and grade of VAE during abdominal myomectomy in the supine position in comparison to those in the head-up tilt position using transesophageal echocardiography. Materials and Methods In this study, 84 female patients of American Society of Anesthesiologist physical status I or II who were scheduled for myomectomy under general anesthesia were included. Patients were randomly divided into two groups: supine group and head-up tilt group. Transesophageal echocardiography images were videotaped throughout the surgery. The tapes were then reviewed for VAE grading. Results In the supine group, 10% of the patients showed no VAE. Moreover, 10% of the patients were classified as grade I VAE, while 50% were categorized as grade II, 22.5% as grade III, and 7.5% as grade IV. In the head-up tilt group, no VAE was detected in 43.2% of the patients. In addition, 18.2% of the patients were classified as grade I VAE, 31.8% as grade II, and 6.8% as grade III; no patients showed grade IV. VAE grade in the head-up tilt group was significantly lower than that in the supine group (p<0.001). Conclusion The incidence and grade of VAE in the head-up tilt group were significantly lower than those in the supine group during abdominal myomectomy.

Suxamethonium induces a prompt increase in the bispectral index

Abstract Upon inducting general anesthesia in the operating room, we have observed a prompt increase in the bispectral index (BIS) after the intravenous injection of suxamethonium. We hypothesized that the cause of this BIS increase is muscle hyperactivity owing to fasciculation. However, no reports have been published regarding this abrupt increase in the BIS upon the induction of general anesthesia by suxamethonium. To investigate the degree of change in the BIS in patients receiving anesthesia with suxamethonium, we performed a prospective observational study of 63 participants who underwent closed reduction for nasal bone fracture. Anesthesia was induced by the total intravenous administration of anesthetics and 1.5 mg kg−1 of suxamethonium was injected intravenously upon achieving BIS between 45 and 55. Intubation was performed after fasciculation. Electromyograms and BIS values were recorded from the induction of suxamethonium until 15 minutes after intubation. The mean BIS values were 95.4, 48.5, and 69.3 before induction, before the intravenous injection of suxamethonium, and immediately after fasciculation, respectively. The BIS value immediately after fasciculation (69.3 ± 10.6) was significantly higher than the cutoff BIS value of 60 (P < .001). Although fasciculation after the intravenous injection of suxamethonium resulted in the prompt increase of the BIS to values over 60, none of the participants was awake during surgery. In conclusion, the administration of suxamethonium resulted in the postfasciculation increase of the BIS to an average value of 69.3 without affecting the patients state of consciousness.

Diagnostic Accuracy of the Neck Tornado Test as a New Screening Test in Cervical Radiculopathy

Background: The Spurling test, although a highly specific provocative test of the cervical spine in cervical radiculopathy (CR), has low to moderate sensitivity. Thus, we introduced the neck tornado test (NTT) to examine the neck and the cervical spine in CR. Objectives: The aim of this study was to introduce a new provocative test, the NTT, and compare the diagnostic accuracy with a widely accepted provocative test, the Spurling test. Design: Retrospective study. Methods: Medical records of 135 subjects with neck pain (CR, n = 67; without CR, n = 68) who had undergone cervical spine magnetic resonance imaging and been referred to the pain clinic between September 2014 and August 2015 were reviewed. Both the Spurling test and NTT were performed in all patients by expert examiners. Sensitivity, specificity, and accuracy were compared for both the Spurling test and the NTT. Results: The sensitivity of the Spurling test and the NTT was 55.22% and 85.07% (P < 0.0001); specificity, 98.53% and 86.76% (P = 0.0026); accuracy, 77.04% and 85.93% (P = 0.0423), respectively. Conclusions: The NTT is more sensitive with superior diagnostic accuracy for CR diagnosed by magnetic resonance imaging than the Spurling test.

Site symmetry of Yb3+ in In0.5Ga0.5P

Abstract The site symmetry of Yb 3+ in In 0.5 Ga 0.5 P grown by liquid phase epitaxy has been investigated using a polarized luminescence spectroscopic technique. The site symmetry of indium in In 0.5 Ga 0.5 P was lowered from T d to C 2v resulting from substitution of indium by ytterbium. The lowering symmetry was confirmed by the spectroscopic observation of the splits of Γ 8 levels of T d in C 2v symmetry. The substitutional site symmetry of Yb 3+ in In 0.5 Ga 0.5 P, i.e. Yb ln 3+ , was revealed as C 2v .