Randomized crossover study assessing oropharyngeal leak pressure and fiber optic positioning : Laryngeal Mask Airway Supreme™ versus Laryngeal Tube LTS II™ size 2 in non-paralyzed anesthetized children.

BACKGROUND: As there are currently no data available comparing the practicability of the laryngeal mask airway (LMA) Supreme™ size 2 versus the laryngeal tube LTS II™ size 2 in children, this trial was conducted to quantify the differences between these two airway devices concerning leak pressure and fiber optic-controlled positioning in non-paralyzed, anesthetized pediatric patients. METHODS: A total of 56 children aged 1-6 years and weighing between 11 and 23 kg were enrolled in the study. Anesthesia was intravenously induced according to local standards using fentanyl and propofol. After induction of anesthesia both airway devices were inserted consecutively in accordance with the randomization protocol. RESULTS: The mean oropharyngeal leak pressure was significantly higher for the LTS II™ (33±8 cmH2O) than for the LMA Supreme™ (21±7 cmH2O, p < 0.0001). Fiber optic position monitoring was better when the LMA Supreme™ was used (p  < 0.001). The first attempt success rates for insertion (55Supreme LMA vs. 43LTSII, p < 0.001), the insertion time (25 s Supreme LMA vs. 34 s LTSII, p < 0.04) and the frequency of bloodstaining (0Supreme LMA vs 4LTSII, p < 0.04) for the initially used device were better for the LMA Supreme™ than the laryngeal tube LTS II™. CONCLUSION: We conclude that oropharyngeal leak pressure, fiber optic position, first attempt insertion success rate and bloodstaining differed between the LMA Supreme™ and the LTS II™ in children.

Astronomy. ASASSN-15lh: A highly super-luminous supernova.

We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of Mu ,AB = -23.5 ± 0.1 and bolometric luminosity Lbol = (2.2 ± 0.2) × 10(45) ergs s(-1), which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (MK ≈ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1 ± 0.2) × 10(52) ergs, challenging the magnetar model for its engine.

A randomised, non-crossover study of the GuardianCPV Laryngeal Mask versus the LMA Supreme in paralysed, anaesthetised female patients.

We investigated the hypothesis that the oropharyngeal leak pressure would differ between the GuardianCPV™ and the LMA Supreme™ in anaesthetised patients. We randomly assigned 120 patients to receive either the GuardianCPV or the LMA Supreme for airway management. Oropharyngeal leak pressure was measured during cuff inflation from 0 to 40 ml in 10-ml steps. In addition, intracuff pressure, fibreoptic position of the airway and drain tube, device insertion success, ventilation success, blood staining and airway morbidity were determined. Mean (SD) oropharyngeal leak pressures for clinically acceptable cuff volumes of 20-40 ml were 31 (7) cmH2O for the GuardianCPV and 27 (7) cmH2O for the LMA Supreme (p < 0.0001); mean (SD) intracuff pressures were 68 (33) cmH2O and 88 (43) cmH2O (p < 0.0001), respectively. We found no differences in device insertion success, ventilation success, fibreoptic position of the airway and drain tube, blood staining or airway morbidity. We conclude that the oropharyngeal leak pressure is better for the GuardianCPV than for the LMA Supreme in anaesthetised patients.

Archie Brain: celebrating 30 years of development in laryngeal mask airways.

The practice of anaesthesia was revolutionised by the ideas of Archie Brain. The routine use of a facemask to manage the airway was not a hands-free technique, despite the development of various harnesses, and made adequate record-keeping difficult. The tracheal tube was associated with some morbidity, which some felt was unsuitable for day surgery. Brain developed an airway management device that was less stressful to the patient than tracheal intubation, and was, however, as safe as using a facemask and airway. Brain also hoped his device would function for cases where mask ventilation was particularly difficult and thus give anaesthetists a safer alternative to a complex intubation, especially in emergency scenarios.

LMA ProSeal(TM) vs. i-Gel(TM) in ventilated children: a randomised, crossover study using the size 2 mask.

BACKGROUND: The Laryngeal Mask Airway (LMA) ProSeal(TM) and the i-Gel(TM) are two extraglottic devices with either an inflatable cuff or a non-inflatable cuff. AIM: We test the hypothesis that oropharyngeal leak pressure and fiberoptic position of the airway tube differ between the size 2 LMA ProSeal(TM) and the i-Gel(TM) in non-paralysed ventilated children. METHODS: Fifty-one children aged 1.5-6 years weighing 10-25 kg were studied using a crossover design. Anaesthesia was with remifentanil/propofol mixture. The LMA ProSeal(TM) and the i-Gel(TM) were inserted into each patient in random order. RESULTS: Oropharyngeal leak pressure for the LMA ProSeal(TM) and the i-Gel(TM) was similar at 22 (5) and 21 (5) cm H(2) O, respectively. Fiberoptic position of the airway tube for the LMA ProSeal(TM) and the i-Gel(TM) was similar, with the vocal cords visible from the distal airway tube in 94% and 96%, respectively. CONCLUSION: We conclude that oropharyngeal leak pressure and fiberoptic position of the airway tube are similar for the size 2 LMA ProSeal(TM) and i-Gel(TM) in non-paralysed ventilated children.

Similar oropharyngeal leak pressures during anaesthesia with i-gel, LMA-ProSeal and LMA-Supreme Laryngeal Masks.

INTRODUCTION: We test the hypothesis that there are differences in performance among three extra-glottic airway devices during spontaneous breathing anaesthesia. METHODS: One hundred and fifty consecutive patients (ASA Grade 1-2, aged 18-80 yr) were randomly allocated for airway management with the i-gel (Intersurgical Ltd, Wokingham, Berkshire UK), the LMA-ProSeal and the LMA-Supreme (The Laryngeal Mask Company Ltd, Wooburn Green, Bucks, UK). Anaesthesia was with fentanyl/propofol/sevoflurane mixture. A laryngoscope-guided, gastric tube-guided technique was used for insertion. The following primary variables were assessed: ease of insertion, effective airway time, anatomical position, oropharyngeal leak pressure among devices, and change in oropharyngeal leak pressure between 30 and 60 minutes for each device during the spontaneous breathing anaesthesia. RESULTS: Differences detected were that the LMA-Supreme was easier to insert and had a shorter effective airway time than the LMA-Proseal and i-gel. Anatomical position was better for the LMA-Supreme than for the i-gel. Oropharyngeal leak pressures were similar among devices during apnoea and spontaneous ventilation, but much higher than in the first generation classic type of laryngeal masks. There were no changes in oropharyngeal leak pressure for any device during the spontaneous breathing phase. There were no differences in performance for any variable between the LMA-ProSeal and i-gel. CONCLUSION: The LMA-Supreme is easier and quicker to insert than the LMA-ProSeal and i-gel using a laryngoscope-guided, gastric tube-guided technique and is associated with better anatomical positioning than the i-gel. Oropharyngeal leak pressures are similar among devices.

Directly measured mucosal pressures produced by the i-gel™ and Laryngeal Mask Airway Supreme™ in paralysed anaesthetised patients.

The i-gel™ and LMA Supreme™ are extraglottic airway devices with non-inflatable and inflatable cuffs, respectively. We hypothesised that directly measured mucosal pressures would differ between these devices in anesthetised paralysed patients. Thirty patients were randomly allocated to receive one of these two devices. Four pressure sensors were attached to all airway devices used to measure mucosal pressure at the base of the tongue, the distal oropharynx, the hypopharynx and the pyriform fossa. At these four places, median (IQR [range]) i-gel mucosal pressures were 8.0 (2.7-10.7 [0-26.7]), 5.0 (2.7-7 [1.0-37.3]), 9.3 (2.7-13.3 [0-22.7] and 8.0 (2.7-10.7 [0-25.3]) cmH(2)O, respectively, and for the LMA Supreme, these were 5.0 (0.5-8.0 [0-33]), 4.0 (1.3-9.3 [0-24]), 10.7 (4-17.3 [0-26.7]) and 8.0 (0-10.7 [0-36]) cmH(2)O, respectively. Mucosal pressures were low and similar for both devices. The LMA Supreme mucosal pressures were higher in the hypopharynx than in the distal oropharynx (p = 0.04) and base of the tongue (p = 0.011). There were no pressure differences between the locations for the i-gel.

Comparison of guided insertion of the LMA ProSeal vs the i-gel.

In a randomised, non-crossover study, we tested the hypothesis that the ease of insertion using a duodenal tube guided insertion technique and the oropharyngeal leak pressure differ between the LMA ProSeal and the i-gel in non-paralysed, anesthetised female subjects. One hundred and fifty-two females aged 19-70 years were studied. Insertion success rate, insertion time and oropharyngeal leak pressure were measured. First attempt and overall insertion success were similar (LMA ProSeal, 75/76 (99%) and 76/76 (100%); i-gel 73/75 (97%) and 75 (100%), respectively). Mean (SD) insertion times were similar (LMA ProSeal, 40 (16) s; i-gel 43 (21) s). Mean oropharyngeal leak pressure was 7 cmH(2) O higher with the LMA ProSeal (p < 0.0001). Insertion of the LMA ProSeal and i-gel is similarly easy using a duodenal tube guided technique, but the LMA ProSeal forms a more effective seal for ventilation.

Size and albedo of Kuiper belt object 55636 from a stellar occultation.

The Kuiper belt is a collection of small bodies (Kuiper belt objects, KBOs) that lie beyond the orbit of Neptune and which are believed to have formed contemporaneously with the planets. Their small size and great distance make them difficult to study. KBO 55636 (2002 TX(300)) is a member of the water-ice-rich Haumea KBO collisional family. The Haumea family are among the most highly reflective objects in the Solar System. Dynamical calculations indicate that the collision that created KBO 55636 occurred at least 1 Gyr ago. Here we report observations of a multi-chord stellar occultation by KBO 55636, which occurred on 9 October 2009 ut. We find that it has a mean radius of 143 +/- 5 km (assuming a circular solution). Allowing for possible elliptical shapes, we find a geometric albedo of in the V photometric band, which establishes that KBO 55636 is smaller than previously thought and that, like its parent body, it is highly reflective. The dynamical age implies either that KBO 55636 has an active resurfacing mechanism, or that fresh water-ice in the outer Solar System can persist for gigayear timescales.

Insertion and use of the LMA Supreme in the prone position.

We investigated whether insertion of an LMA Supreme and its use for maintenance of anaesthesia is feasible in the prone position. Forty adult patients positioned themselves prone and were given propofol until the Bispectral Index was < 50. A size-4 LMA Supreme was inserted by experienced anaesthetists. Ease of insertion, ease of ventilation, efficacy of seal, ease of gastric tube insertion, blood staining, postoperative sore throat, and other complications were recorded. Insertion was successful at the first and second attempt in 37 (92.5%) and 3 (7.5%) patients, respectively. The mean (SD) insertion time was 21 (15) s. Oropharyngeal leak pressure was greater in females than males (29 (4) vs 25 (4) cmH(2)O, respectively, p = 0.01). Adequate ventilation was achieved in all patients. Gastric tube placement was successful in all patients. The frequency of blood staining and sore throat was 7.5% each. No other complications were noted. We conclude that use of the LMA Supreme in the prone position by experienced users is feasible.

The laryngeal mask airway Supreme--a single use laryngeal mask airway with an oesophageal vent. A randomised, cross-over study with the laryngeal mask airway ProSeal in paralysed, anaesthetised patients.

The LMA Supreme is a new extraglottic airway device which brings together features of the LMA ProSeal, Fastrach and Unique. We test the hypothesis that ease of insertion, oropharyngeal leak pressure, fibreoptic position and ease of gastric tube placement differ between the LMA ProSeal and the LMA Supreme in paralysed anesthetised patients. Ninety-three females aged 19-71 years were studied. Both devices were inserted into each patient in random order. Two attempts were allowed. Digital insertion was used for the first attempt and guided insertion for the second attempt. Oropharyngeal leak pressure and fibreoptic position were determined during cuff inflation from 0 to 40 ml in 10 ml increments. Gastric tube insertion was attempted if there was no gas leak from the drain tube. First attempt and overall insertion success were similar (LMA ProSeal, 92% and 100%; LMA Supreme 95% and 100%). Guided insertion was always successful following failed digital insertion. Oropharyngeal leak pressure was 4-8 ml higher for the LMA ProSeal over the inflation range (p < 0.001). Intracuff pressure was 16-35 cm higher for the LMA ProSeal when the cuff volume was 20-40 ml (p < 0.001). There was an increase in oropharyngeal leak pressure with increasing cuff volume from 10 to 30 ml for both devices, but no change from 0 to 10 ml and 30-40 ml. There were no differences in the fibreoptic position of the airway or drain tube. The first attempt and overall insertion success for the gastric tube was similar (LMA ProSeal 91% and 100%; LMA Supreme 92% and 100%). We conclude that ease of insertion, gastric tube placement and fibreoptic position are similar for the LMA ProSeal and LMA Supreme in paralysed, anaesthetised females, but oropharyngeal leak pressure and intracuff pressure are higher for the LMA ProSeal.

Determinants of patellar tracking in total knee arthroplasty.

BACKGROUND: Optimizing patellar tracking in total knee arthroplasty is a surgical priority. Despite this, a comparison of the effects of different component placements on patellar tracking is not available; the biomechanical impact of the patellar resection angle has not been studied; and the similarity between intraoperative and postoperative effects, fundamental to improving patellar tracking, is unknown. Our objective was to compare the impact of the major controllable femoral, tibial and patellar component positions on patellar kinematics during both passive and loaded flexion. METHODS: We tested eight cadaveric knee specimens in two rigs, simulating intraoperative and weightbearing flexion. Optoelectronic marker arrays were attached to the femur, tibia and patella to record kinematics throughout the range of motion. We modified posterior-stabilized fixed-bearing knee components to allow for five types of variations in component placement in addition to the neutral position: femoral component rotation, tibial component rotation, patellar resection angle, patellar component medialization and additional patellar thickness, for a total of 11 individual variations. FINDINGS: The major determinants of patellar tilt and shift were patellar component medialization, patellar resection angle and femoral component rotation. The relative order of these variables depended on the structure (bone or component), kinematic parameter (tilt or shift) and flexion angle (early or late flexion). Effects of component changes were consistent between the intraoperative and weightbearing rigs. INTERPRETATION: To improve patellar tracking, and thereby the clinical outcome, surgeons should focus on patellar component medialization, patellar resection angle and femoral component rotation. These have been linked with anterior knee pain as well. Neither tibial component rotation nor patellar thickness should be adjusted to improve patellar tracking.

ProSeal laryngeal mask airway for cardiac surgery after airway rescue.

We present the case of the successful use of a ProSeal laryngeal mask airway in a severe obese 41-year-old women with a difficult airway, scheduled to undergo cardiac surgery (off-pump coronary artery bypass). Two intubation attempts failed and face mask ventilation became impossible with rapidly falling peripheral oxygen saturation. A ProSeal laryngeal airway was railroaded over a tracheal tube guide, a gastric tube was inserted along the drain tube and the patient underwent positive pressure ventilation, resulting in normal gas exchange and an oropharyngeal leak pressure > 40 cm H2O. The decision was taken to proceed with the ProSeal as the airway during the surgical intervention. Surgery was uneventful and the ProSeal was removed on the ICU three hours later. This case reports illustrates the successful use of a guided insertion of the ProSeal laryngeal mask for airway rescue in cardiac surgery.

Intraoperative vs. weightbearing patellar kinematics in total knee arthroplasty: a cadaveric study.

BACKGROUND: During knee replacement surgery, surgeons optimize intraoperative patellar tracking with the aim of optimizing postoperative tracking. This link has not been investigated to date. Our research questions were: (1) How well do patellar kinematics correlate between passive and weightbearing flexion across numerous changes in component placement? (2) How do the kinematics differ between the two loading configurations? METHODS: Eight cadaveric knee joints with modified knee components that allowed 11 different femoral, tibial and patellar placements were tested in two experimental rigs simulating intraoperative and weightbearing dynamic flexion. Baseline placement had all components in neutral position. Pearson correlation coefficients were calculated for absolute baseline kinematics and for relative kinematics due to changes in component position (i.e., the 10 altered positions vs. baseline). FINDINGS: Correlations between intraoperative and weightbearing rigs for absolute baseline kinematics were unpredictable, ranging from poor to excellent (mean 0.56 for tilt and mean 0.50 for shift). Correlations between rigs for changes in tilt and shift, i.e. relative kinematics, were strong (>0.8) or very strong (>0.9), with the exception of shift in early flexion (0.54). Differences in relative kinematics, which averaged 2.2 degrees in tilt (standard deviation 1.8 degrees ) and 1.6mm in shift (standard deviation 1.7mm), were notably smaller and less variable than differences in absolute kinematics, which averaged 4.2 degrees in tilt (standard deviation 3.6 degrees ) and 4.3mm in shift (standard deviation 3.9mm). INTERPRETATION: The results of this study suggest that, while absolute kinematics may differ between conditions, if a surgeon adjusts a component position to improve patellar kinematics intraoperatively, the effects of such a geometric change will likely carry through to the postoperative joint.

A study of airway management using the ProSeal LMA laryngeal mask airway compared with the tracheal tube on postoperative analgesia requirements following gynaecological laparoscopic surgery.

In a randomised double blind prospective study, we tested the hypothesis that postoperative pain is lower in patients who receive an ProSeal LMA laryngeal mask airway compared with a tracheal tube. One hundred consecutive female patients (ASA I-II, 18-75 years) undergoing laparoscopic gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. Anaesthesia management was identical for both groups and included induction of anaesthesia using propofol/fentanyl, and maintenance with propofol/remifentanil, muscle relaxation with rocuronium, positive pressure ventilation, gastric tube insertion, dexamethasone/tropisetron for anti-emetic prophylaxis, and diclofenac for pain prophylaxis. All types of postoperative pain were treated using intravenous patient-controlled analgesia (PCA) morphine. Patients and postoperative staff were unaware of the airway device used. Data were collected by a single blinded observer. We found that pain scores were lower for the ProSeal LMA at 2 h and 6 h but not at 24 h. Morphine requirements were lower for the ProSeal LMA by 30.4%, 30.6% and 23.3% at 2, 6 and 24 h, respectively. Nausea was less common with the ProSeal LMA than with the tracheal tube at 2 h and 6 h but not at 24 h. There were no differences in the frequency of vomiting, sore throat, dysphonia or dysphagia. We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery.

Postoperative nausea, vomiting, airway morbidity, and analgesic requirements are lower for the ProSeal laryngeal mask airway than the tracheal tube in females undergoing breast and gynaecological surgery.

BACKGROUND: We test the hypothesis that the frequency of postoperative nausea and vomiting is similar for the ProSeal laryngeal mask airway (LMA) and the tracheal tube. METHODS: Two hundred consecutive female patients (ASA I-II, 18-75 yr) undergoing routine breast and gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. RESULTS: Ventilation was better and airway trauma less frequent for the ProSeal LMA. For the ProSeal group, the time spent in the post-anaesthesia care unit was shorter (69 vs 88 min, P < 0.0001); fewer doses of tropisetron were required in the post-anaesthesia care unit (P < or = 0.001) and ward (P = 0.004); morphine requirements were lower in the post-anaesthesia care unit (6.0 vs 8.1 mg, P = 0.005) and ward (6.1 vs 8.9, P = 0.004); nausea was less frequent at all times (overall: 13% vs 53%, P < 0.0001); vomiting was less frequent at 2 h (4% vs 18%, P = 0.003) and 24 h (5% vs 19%, P = 0.004); and sore throat was less frequent at all times (overall: 12% vs 38%, P < 0.0001). CONCLUSIONS: The ProSeal LMA reduced the absolute risk of postoperative nausea and vomiting by 40% (53-13%). In patients without the need for morphine, the ProSeal LMA reduced the absolute risk of postoperative nausea and vomiting by 23% (37-14%). We conclude that the frequency of postoperative nausea, vomiting, airway morbidity, and analgesic requirements is lower for the ProSeal LMA than the tracheal tube in females undergoing breast and gynaecological surgery.

The effect of high concentration potassium permanganate on protein contamination from metallic and synthetic rubber airway equipment.

We tested the hypothesis that supplementary cleaning using potassium permanganate 8 mg.l(-1) eliminates protein deposits from the reusable metallic and synthetic rubber airway equipment. Twenty Macintosh laryngoscope blades (surgical steel), 20 pairs of Magill's forceps (surgical steel) and 20 Guedel airways (synthetic rubber) were allocated to two groups for supplementary cleaning. In group A, the device was immersed in potassium permanganate 8 mg.l(-1). In group B (controls), the device was immersed in sterile water. The devices were then immersed in a protein staining solution, rinsed and the severity of staining was scored. In addition, the devices were inspected for tissue and then tested for occult blood. Protein contamination was lower in the potassium permanganate group for all devices (each device: p < 0.0001). There was no staining detected in the permanganate group. In the permanganate group, dried tissue was detected in the teeth of one pair of forceps, which was not detected following supplementary cleaning. Additionally, occult blood was detected on two pairs of forceps and a laryngoscope blade, which was not detected following supplementary cleaning. In the control group, no tissue was detected but one pair of forceps and two laryngoscope blades tested positive for occult blood before and after supplementary cleaning. We conclude that supplementary cleaning using potassium permanganate 8 mg.l(-1) eliminates protein deposits from re-usable metallic and synthetic rubber airway equipment.

The proseal laryngeal mask airway in prone patients: a retrospective audit of 245 patients.

The use of the classic laryngeal mask airway (classic LMA) in the prone position is controversial, but the ProSeal laryngeal mask airway (ProSeal LMA) may be more suitable as it forms a better seal and provides access to the stomach. In the following retrospective audit, we describe our experience with the insertion of and maintenance of anaesthesia with, the ProSeal LMA in 245 healthy adults in the prone position by experienced users. The technique involved (1) the patient adopting the prone position with the head to the side and the table tilted laterally; (2) pre-oxygenation to end-tidal oxygen >90%; (3) induction of anaesthesia with midazolam/alfentanil/propofol; (4) facemask ventilation (5) a single attempt at digital insertion and if unsuccessful a single attempt at laryngoscope-guided, gum elastic bougie-guided insertion; (6) gastric tube insertion; (7) maintenance of anaesthesia with sevoflurane/O/N2O; (8) volume controlled ventilation at 8-12 ml/kg; (9) emergence from anaesthesia in the supine position; and (10) removal ofthe ProSeal LMA when awake. Facemask ventilation was always successful. ProSealLMA insertion was successful in all patients: 237 with digital insertion and eight with bougie-guided insertion. Ventilation was successful in all patients. Gastric tube insertion was successful in all patients. Correctable partial airway obstruction occurred in three patients, but there was no hypoxia, hypercapnoea, displacement, regurgitation, gastric insufflation or airway reflex activation. Our findings suggest that the insertion of and maintenance of anaesthesia with the ProSeal LMA is feasible in the prone position by experienced users.