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One promising approach for the induction of transplant tolerance is the pre-treatment of transplant recipients with donor MHC-alloantigen. Our study focuses on the oral delivery of MHC-antigen encoding genes via chitosan-DNA nanoparticles to modulate the alloimmune response in order to reduce the development of transplant arteriosclerosis, the hallmark feature of chronic rejection after heart transplantation. Therefore, we performed fully allogeneic mouse abdominal aortic transplants using C57BL/6 (H2(b)) mice as donors and CBA.J (H2(k)) mice as recipients. Aortic grafts were analyzed by histology and morphometry on day 30 after transplantation, levels of circulating alloantibodies were detected by FACS analysis. Pre-treatment of recipient mice with chitosan-DNA nanoparticles encoding for K(b), one of the MHC-I molecules of the donor, resulted in a significant reduction of intimal proliferation compared to untreated controls. When Ovalbumin was fed instead of K(b) encoding nanoparticles (K(b)-NP) or Balb/c (H2(d)) grafts were used instead of C57BL/6 (H2(b)) grafts as antigen controls, both groups showed no reduction of intimal thickness indicating an antigen-specific mechanism. In addition, analysis of peripheral blood of the transplanted mice showed significant suppression of alloantibody formation in the K(b)-NP fed group compared to all other allogeneic transplanted groups suggesting modulation of the humoral immune response. These results demonstrate the potential of chitosan-DNA nanoparticles to induce K(b)-specific tolerance and to reduce the development of transplant arteriosclerosis., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Study Objective: To test the hypothesis that a virtual reality (VR) airway simulator (the AccuTouch Virtual Reality Bronchsocopy Simulator; Immersion Medical, Gaithersburg, MD) can be used to teach residents basic fiberoptic intubation (FOI) skills effectively., Design: Observational study., Setting: University anesthesiology department., Intervention: Supervised training was done using a VR airway simulator., Measurements: Time to intubation before and after a 4-day training period using an adult VR FOI scenario and time to intubation using a fresh human cadaver two weeks after the training experience were measured., Main Results: Residents were able to significantly improve time to intubation in the VR scenario (114 vs 75 seconds; P = 0.001). Novices differed from experienced attending anesthesiologists in time to intubation in the VR scenario, before but not after training (114 vs 79 seconds compared with 75 vs 72 seconds). Novices who had been trained with the simulator performed significantly faster in the cadaver than novices who had not (24 vs 86 seconds; P < 0.001). Furthermore, there was no difference in time to intubation in the cadaver between trained novices and experienced attending anesthesiologists (24 vs 23 seconds; P > 0.05)., Conclusion: Use of a VR airway simulator enables anesthesia residents to acquire basic FOI skills comparable to those of experienced anesthesiologists in a human cadaver.

Despite the use of alternative training methods and efforts to structure training, it remains a challenge to ensure that every anaesthesia trainee gains sufficient experience in the use of core techniques of airway management. As less time is spent in the operating room during training, it becomes less likely that trainees will be exposed to an adequate number of challenging airway cases that enable them to practise advanced techniques of airway management under supervision. Nowadays the only way to overcome this deficit in anaesthesia training is to prepare trainees as well as possible outside the operating room so that clinical training opportunities can be used most effectively when they arise. Sufficient training can only be ensured when the required equipment and time are provided. Therefore, particularly in the light of increasing economic pressures, it is necessary to address the responsibilities of everyone involved in the training process. Here, we critically review traditional and recent modalities of anaesthesia training, assess their value, and describe a multi-modal approach to airway management education.

Background: Tracheal intubation and positive end-expiratory pressure (PEEP) are frequently used in children to avoid airway closure and atelectasis during general anaesthesia. Also, the laryngeal mask airway (LMA(dagger)) is frequently used. However, one of the limitations with its use in children is that its low-pressure seal is often inadequate for positive pressure ventilation with PEEP. The ProSeal LMA (PLMA) has been shown to form a more effective seal than the Classic LMA. The ability to apply PEEP with the PLMA might improve gas exchange during positive pressure ventilation in children when the LMA is used., Methods: Twenty anaesthetized, non-paralysed children aged 55 (range 27-89) months, weighing 18 (sd 3) kg, were randomly allocated into two groups. Anaesthesia management and positive pressure ventilation were standardized. Size 2 and 2(1/2) PLMA were used. Artificial ventilation in Group I was with pressure controlled ventilation (PCV) and PEEP=5 cm H(2)O, in Group II with PCV without PEEP. A Fi(o(2)) = 1.0 was used for 20 min during induction of anaesthesia. Sixty minutes after induction of anaesthesia an arterial blood gas sample was taken under a Fi(o(2)) = 0.3., Results: Groups were comparable with respect to demographic data. Pa(o(2)) in Group I [22.1 (1.6) kPa] was significantly (P=0.001) higher than in Group II [19.2 (1.7) kPa]., Conclusions: The PLMA can be used for PCV with PEEP in paediatric patients. Application of PEEP improves gas exchange.

Objective: Evaluation of the LMA-ProSeal for positive pressure ventilation (PPV) in the pig., Study Design: Prospective observational study., Animals: Twelve German country pigs, weighing 25-62 kg., Method: Lungs of pigs were mechanically ventilated under general anaesthesia using the LMA-ProSeal. The ease of insertion, number of attempts and total time until placement of the LMA-ProSeal and gastric tube were recorded. Bronchoscopy was performed to determine the position of the LMA-ProSeal and to detect signs of aspiration. Ventilation variables and the leak airway pressure (P(leak)) were measured. An arterial blood gas sample was taken to determine the adequacy of ventilation., Results: The airway was secured in all pigs within 39 +/- 19 seconds (27-51). Different sizes of LMA-ProSeal were used; up to 30 kg: size 3, up to 43 kg: size 4; and above 43 kg: size 5. In all but one animal the P-LMA and gastric tube were inserted at the first attempt. In nine animals gastric fluid was drained through the gastric tube. There was no evidence of aspiration in any animal. The mean [+/-SD (95%CI)]P(leak) was 28.8 +/- 7.5 cm H(2)O (24.06-33.60) and normal ventilation was achieved in all animals., Conclusions: The results of this study indicate that the airway of pigs weighing 25-62 kg can be secured safely and reliably with the sizes 3, 4 and 5 LMA-ProSeal., Clinical Relevance: Endotracheal intubation in pigs can be difficult so there is a risk of hypoxemia in the apnoeic animal. With the LMA-ProSeal the airway can be secured rapidly, safely and reliably. Use of the Standard-LMA under PPV can be associated with gas leakage into the stomach and the subsequent risk of gastric distension and regurgitation. Both the ability to drain the stomach and the high P(leak) of the LMA-ProSeal could contribute to improved protection against aspiration under PPV.

Background: One of the main concerns with the use of the standard laryngeal mask airway (SLMA) in small infants is that its low-pressure seal might be inadequate for positive pressure ventilation so that there is a risk of gas leakage into the stomach with the subsequent risk of regurgitation. The new ProSeal LMA (PLMA) has been shown to form a more effective seal than the SLMA and to facilitate gastric tube placement in adults. The first paediatric size PLMA became available recently., Methods: Thirty anaesthetized, non-paralysed children aged 46 (19) months, weighing 16 (10-21) kg, were studied. The SLMA and PLMA were inserted in random order into each patient. Airway leak pressure and maximum tidal volume were measured. Ease of insertion, quality of initial airway and fibreoptic position were also determined. Gastric tube placement was assessed for the PLMA., Results: The airway leak pressure and maximum tidal volume were significantly higher for the PLMA (P=0.001). Ease of insertion and quality of initial airway were similar for both devices. Air entry into the stomach occurred more frequently with the SLMA (P=0.005). Gastric tube placement was possible in all patients., Conclusions: The size 2 PLMA offered some advantages over the same size of SLMA in this crossover investigation. The high reliability of gastric tube placement and the significantly increased airway leak pressure might have important implications for use of this device for positive pressure ventilation in infants.