Major incidents and complications in otherwise healthy patients undergoing elective procedures: results based on 1.37 million anaesthetic procedures.

BACKGROUND: Improved anaesthesia safety has made severe anaesthesia-related incidents, complications, and deaths rare events, but concern about morbidity and mortality in anaesthesia continues. This study examines possible severe adverse outcomes or death recorded in a large national surveillance system based on a core data set (CDS). METHODS: Cases from 1999 to 2010 were filtered from the CDS database. Cases were defined as elective patients classified as ASA physical status grades I and II (without relevant risk factors) resulting in death or serious complication. Four experts reviewed the cases to determine anaesthetic involvement. RESULTS: Of 1 374 678 otherwise healthy, ASA I and II patients in the CDS database, 36 met the study inclusion criteria resulting in a death or serious complication rate of 26.2 per million [95% confidence interval (CI), 19.4-34.6] procedures, and for those with possible direct anaesthetic involvement, 7.3 per million cases (95% CI, 3.9-12.3). CONCLUSIONS: This is the first study assessing severe incidents and complications from a national outcome-tracking database. Annual identification and review of cases, perhaps with standardized database queries in the respective departments, might provide more detailed information about the cascades that lead to unfortunate outcomes.

SBAR 'flattens the hierarchy' among caregivers.

As a young ensign in the US Navy on a nuclear submarine, Doug Bonacum had to brief the captain of the ship following his night-time shift, reporting about potentially dangerous situations that might emerge. He described the "situation, background, assessment, and recommendation". This nascent SBAR communication tool served temporarily to flatten the hierarchy between the ensign and the ship's captain. Years later at KP, Bonacum developed SBAR for facilitating effective conversations between obstetricians and nurses. SBAR has been implemented in "real-world" environments with excellent results. We are implementing SBAR to facilitate communication in CliniSpace among caregivers in this 3D immersive, virtual learning environment.

CliniSpace: a multiperson 3D online immersive training environment accessible through a browser.

Immersive online medical environments, with dynamic virtual patients, have been shown to be effective for scenario-based learning (1). However, ease of use and ease of access have been barriers to their use. We used feedback from prior evaluation of these projects to design and develop CliniSpace. To improve usability, we retained the richness of prior virtual environments but modified the user interface. To improve access, we used a Software-as-a-Service (SaaS) approach to present a richly immersive 3D environment within a web browser.

[New perspectives in laparoscopic simulation: from students' skills lab to stress evaluation]. / Neue Perspektiven der laparoskopischen Simulation: Vom Studententrainingslabor bis zur Stressevaluation.

BACKGROUND: Application of a LapSim-training model in the Students' Skills Lab as well as the objective evaluation of stress in a virtual operating room scenario offer new perspectives in laparoscopic simulation. METHODS: In a Students' Skills Lab , assessment of learning curves of laparoscopic basic skills and complex tasks was carried out with 28 individuals at a LapSim Virtual Reality (VR)-simulator in a training curriculum consisting of 9 units. In addition, in a virtual operating room scenario, stress evaluation was performed with 18 surgeons by means of a sympathicograph and, in that way, the laparoscopic error and complication rate were recorded. Three different stress reactions (SR 1-3) could be identified. RESULTS: In the Students' Skills Lab, at the beginning of the curriculum (unit 1), the best learning effects together with the improvement of the laparoscopic performance could be presented for the two parameters: Extent of movement of the laparoscopic instruments (length of path as well as degree of deviation from the "optimal course") and duration of the procedure. In the virtual stress scenario, the intraoperative error rate of surgeons with a stress reaction without recovery (SR-1) was lower than of those with recovery (SR-2) or without stress reaction (SR-3). CONCLUSION: Application of the LapSim Virtual Reality (VR)-simulator in the Students' Skills Lab and for stress and crisis simulation represents a new perspective in laparoscopic simulation, which will have to be further evaluated in the future. The transfer to the "real" operating room will have to be continued as a training and scientific validation paradigm.

Three different types of surgeon-specific stress reactions identified by laparoscopic simulation in a virtual scenario.

BACKGROUND: Minimally invasive surgery causes higher mental strain for surgeons than conventional surgery and is significantly more stressful in consecutive cases. This study aimed to investigate whether individual stress responses are associated with intraoperative alterations of manual surgical skills and technical errors of the laparoscopic surgeon. METHODS: The LapSim virtual reality simulator was used. Stress measurement was carried out for 18 surgeons performing a virtual cholecystectomy using the LapSim simulator in the context of the patient simulator provided by the METI Corporation. In the course of the study, the surgeons were exposed to different external stressors (S1-S4) in defined intervals. The activity of the sympathetic nervous system was evaluated by skin resistance with the help of a sympathicograph. RESULTS: Three different surgeon-specific stress reactions (SSR) could be identified. The first, SSR-1, with significant stress reactions during the study without recovery, showed larger laparoscopic extensions of movement but fewer intraoperative complications than SSR-2 (recovery after the stress reactions) or SSR-3 (without significant stress reactions). CONCLUSIONS: The mental load of the laparoscopic surgeon might be highly optimized by continuous activity of the sympathetic nervous system. The question of what extent or quality of stress produces adverse effects remains unclear.

Virtual worlds and team training.

An important component of all emergency medicine residency programs is managing trauma effectively as a member of an emergency medicine team, but practice on live patients is often impractical and mannequin-based simulators are expensive and require all trainees to be physically present at the same location. This article describes a project to develop and evaluate a computer-based simulator (the Virtual Emergency Department) for distance training in teamwork and leadership in trauma management. The virtual environment provides repeated practice opportunities with life-threatening trauma cases in a safe and reproducible setting.

Virtual patient model for multi-person virtual medical environments.

We describe the architecture of a virtual patient model, the Virtual ED Patient, for scenarios in emergency medicine. The model is rule-based, and uses four vital signs as a representation of its state. The model is used in a multi-person learning environment based on online gaming technology. The efficacy of the model and the Virtual ED learning environment is evaluated in a study where advanced medical students and first year residents manage six trauma cases. Pre and post-test performance results show significant learning, with results comparable to those obtained in human manikin simulators. Some future directions for development of the model are also presented.

[Combined simulation training: a new concept and workshop is useful for crisis management in gastrointestinal endoscopy]. / Kombiniertes Simulationstraining: Ein neues Kurskonzept trainiert und verbessert das Krisenmanagement der gastroenterologischen Endoskopie.

INTRODUCTION: Crisis management as well as realistic emergency situations can be trained in the new developed simulation workshop "Gastrointestinal Endoscopy and Crisis Resource Management" by combining a full-scale simulator and the Erlanger Endoscopy Trainer. The aim of the current study was to evaluate the efficiency of the newly developed simulation workshop. METHODS: Endoscopists with more than 12 months experience can train their endoscopic skills and crisis resource management with the help of different simulators. In addition, two different scenarios (GI bleeding with significant blood loss and sedation overdoses) embedded in a realistic surrounding (emergency room) have to be managed by the participants. Vital parameters, endoscopic skills, as well as personal interactions were recorded and graded. RESULTS: 100 participants took part in the newly developed workshop (between June and December 2003). The participants showed a significantly better endoscopic performance and a significantly better crisis management after the standardized training program. CONCLUSIONS: Simulation training plays an essential role in aviation and minimizes the risk for human errors. In the current study it is clearly shown that simulation training is also useful in gastrointestinal endoscopy. The newly developed workshop may thus be of crucial importance to improve personal crisis management. Simulation also leads to an improvement of endoscopic and emergency skills. Accordingly, simulation training should be recommended or offered as an education option in gastrointestinal endoscopy.

High-frequency oscillatory ventilation and an interventional lung assist device to treat hypoxaemia and hypercapnia.

A male patient accidentally aspirated paraffin oil when performing as a fire-eater. Severe acute respiratory distress syndrome (Pa(o(2))/Fi(o(2)) ratio 10.7 kPa) developed within 24 h. Conventional pressure-controlled ventilation (PCV) with high airway pressures and low tidal volumes failed to improve oxygenation. Hypercapnia (Pa(co(2)) 12 kPa) with severe acidosis (pH<7.20) ensued. Treatment with high-frequency oscillatory ventilation (HFOV) and a higher adjusted airway pressure (35 cm H(2)O) improved the Pa(o(2))/Fi(o(2)) ratio within 1 h from 10.7 to 22.9 kPa, but the hypercapnia and acidosis continued. Stepwise reduction of the mean airway pressure (26 cm H(2)O), and oscillating frequencies (3.5 Hz), as well as increasing the oscillating amplitudes (95 cm H(2)O) resulted in an unchanged Pa(co(2)), but oxygenation worsened. The new pumpless extracorporeal interventional lung assist device (ILA, NovaLung, Hechingen, Germany) was therefore used for carbon dioxide elimination to enable a less aggressive ventilation strategy. Pa(co(2)) normalized after initiation of ILA. HFOV with a mean airway pressure of 32 cm H(2)O was maintained, but with a higher oscillatory frequency (9 Hz) and very low oscillatory amplitude (25 cm H(2)O). After 6 days, the patient was transferred to a conventional ventilator, and ILA was discontinued after 13 days without complications.

Gastric insufflation pressure, air leakage and respiratory mechanics in the use of the laryngeal mask airway (LMA) in children.

BACKGROUND: The objective of the present study was to evaluate the prelaryngeal position of the laryngeal mask airway (LMA(TM)) in children, and to determine the influence of mask positioning on gastric insufflation and oropharyngeal air leakage. METHODS: A total of 100 children, 3-11 years old, scheduled for surgical procedures in the supine position under general anaesthesia were studied. After clinically satisfactory LMA placement, tidal volumes were increased stepwise until air entered the stomach, airway pressure exceeded 30 cmH(2)O, or air leakage from the mask seal prevented further increases in tidal volume. LMA position in relation to the laryngeal entrance was verified using a flexible bronchoscope. RESULTS: The insertion of the LMA with a clinically satisfactory position was achieved in all patients at the first attempt. Gastric air insufflation occurred in five of 49 patients with malpositioned LMA. No incident of gastric air insufflation was observed in 51 patients with correctly positioned LMA. The minimum inspiratory pressure leading to mask leakage was 17 cmH(2)O for incorrectly positioned LMA, and 25 cmH(2)O for correctly positioned LMA. Clinically unrecognized LMA malposition was associated with a significantly increased incidence of either oropharyngeal leakage (r = 0.59; P = 0.0001) or gastric insufflation (r = 0.25; P = 0.01). CONCLUSIONS: Clinically undetected LMA malpositioning is a significant risk factor for gastric air insufflation in children between 3 and 11 years, undergoing positive pressure ventilation, especially at inspiratory airway pressures above 17 cmH(2)O.

Initial evaluation of a shoulder arthroscopy simulator: establishing construct validity.

Formal evaluation of surgical simulators is essential before their introduction into training programs. We report our assessment of the Mentice Corp Procedicus shoulder arthroscopy simulator. This study tests the hypothesis of construct validity that experienced surgeons will score better on the simulator than individuals with minimal to no experience with the technique. Thirty-five subjects were stratified into three groups (novice, intermediate, and expert) based on their past 5 years' experience with shoulder arthroscopies. Each subject had an identical session on the simulator and completed anatomic identification, hook manipulations, and scope navigation exercises. We found statistically significant differences among the three groups in hook manipulation and scope navigation exercises, with the expert group performing the exercises more quickly (P =.013) and more accurately (P =.002) than the other two groups. No statistically significant differences were found among the groups in the identification of anatomic landmarks. Experts rated the simulator as an effective teaching tool, giving it a mean score of 4.22 and 4.44 (maximum, 5) for teaching instrument control and triangulation, respectively.

Simulated medical learning environments on the Internet.

Learning anatomy and surgical procedures requires both a conceptual understanding of three-dimensional anatomy and a hands-on manipulation of tools and tissue. Such virtual resources are not available widely, are expensive, and may be culturally disallowed. Simulation technology, using high-performance computers and graphics, permits realistic real-time display of anatomy. Haptics technology supports the ability to probe and feel this virtual anatomy through the use of virtual tools. The Internet permits world-wide access to resources. We have brought together high-performance servers and high-bandwidth communication using the Next Generation Internet and complex bimanual haptics to simulate a tool-based learning environment for wide use. This article presents the technologic basis of this environment and some evaluation of its use in the gross anatomy course at Stanford University.

Volumetric virtual body structures.

Understanding the visuospatial aspects of anatomic structures is one of the most important goals of gross anatomy. Creation of realistic three-dimensional structures of human anatomy has thus been a goal of medical doctors and computer scientists. In this paper, we describe a PC/NT based system in which a user can easily select anatomical structures to be created, along with the chosen connected structures. The system then constructs a three-dimensional volumetric model, a virtual body structure, slice-by-slide. Once the virtual structure is assembled it is possible to "walk" through the volume with coronal, sagittal, and transverse views, or at any angle. The dynamic nature of the system is unique in that it allows for real time choice of volumetric body structures to be created, their rapid generation, and the ability to manipulate the resulting visualization.

Simulated learning environments in anatomy and surgery delivered via the next generation internet.

The Next Generation Internet (NGI) will provide high bandwidth, guaranteed Quality of Service, collaboration and security, features that are not available in today's Internet. Applications that take advantage of these features will need to build them into their pedagogic requirements. We present the Anatomy Workbench and the Surgery Workbench, two applications that require most of these features of the NGI. We used pedagogic need and NGI features to define a set of applications that would be difficult to operate on the current Internet, and that would require the features of the NGI. These applications require rich graphics and visualization, and extensive haptic interaction with biomechanical models that represent bony and soft tissue. We are in the process of implementing these applications, and some examples are presented here. An additional feature that we required was that the applications be scalable such that they could run on either on a low-end desktop device with minimal manipulation tools or on a fully outfitted high-end graphic computer with a realistic set of surgical tools. The Anatomy and Surgery Workbenches will be used to test the features of the NGI, and to show the importance of these new features for innovative educational applications.

Temporal dynamics of lung aeration determined by dynamic CT in a porcine model of ARDS.

We used dynamic CT to identify two different time constants of lung aeration and their individual contribution to the total increase in cross-sectional lung area in healthy and experimentally damaged lungs. In five healthy pigs, inflation and deflation between 0 and 50 cm H2O was imposed during dynamic (250 ms/image) CT acquisition, and repeated after experimental lung injury by saline lavage. The fractional areas of density ranges, which represent aerated lung parenchyma, were determined planimetrically, and their time for expansion during the manoeuvre was fitted using a bi-exponential model. Thus, two compartments, their sizes, i.e. their relative contributions to lung area aerated by the manoeuvre, and their specific time constants (tau) were sought. Healthy lungs were characterized best by a one-compartmental behaviour with one tau only, both during inflation (median tau=0.5 s; range 0.4-0.6 s) and deflation (1.2 s; 1.1-1.3 s). In damaged lungs two compartments were found both during inspiration and expiration, with 86% (78-87%) of the recruitable lung area following a short tau of 0.5 s (0.5-0.6), and 14% (13-22%) following a longer tau of 9.1 s (8-16.8 s) during inflation. During expiration, damaged lungs had a short tau of 0.8 s (0.5-1.0 s) for 94% (84-100%) of deflated lung area, and a longer tau of 26.5 s (7.1-34.3 s) for 6% (0-16%). We conclude that dynamic CT indicates the relative size and temporal behaviour of functional compartments in normal and abnormal lungs. Our findings suggest that after lung damage, cyclic ventilation with inspiratory periods of <10 s duration will not achieve maximum recruitment for a chosen inspiratory pressure. In ARDS, the short expiratory tau predisposes to atelectasis formation if expiratory times are >1 s.

Intention tremor, parkinsonism, and generalized brain atrophy in male carriers of fragile X.

The authors report five elderly men with the fragile X premutation who had a progressive action tremor associated with executive function deficits and generalized brain atrophy. These individuals had elevated fragile X mental retardation 1 gene (FMR1) messenger RNA and normal or borderline levels of FMR1 protein. The authors propose that elevations of FMR1 messenger RNA may be causative for a neurodegenerative syndrome in a subgroup of elderly men with the FMR1 premutation.