Tube tip and cuff position using different strategies for placement of currently available paediatric tracheal tubes.

BACKGROUND: Tracheal tube tip and cuff positions of different cuffed paediatric tracheal tube brands in the trachea can vary with design. METHODS: Data from three clinical studies with measured tracheal lengths were pooled in a database including 422 children aged from birth to 16 yr. Dimensional data of seven cuffed paediatric tracheal tube brands (ID 3.0-7.0 mm) were recorded. Positions of tracheal tube tip and upper cuff border were calculated for each of the 422 tracheas using depth mark based tracheal tube placement, placement of the tracheal tube tip at a calculated safety distance above the carina, and mid-tracheal tube placement. Percentage of accidental bronchial intubations and tracheal tube cuff positions in the subglottic or supraglottic region were calculated. RESULTS: Depth mark based tracheal tube placement resulted in accidental bronchial intubation of up to 18% of cases and tracheal tube cuffs being placed in the subglottic region in up to 91%. Tracheal tube tip placement at a calculated safety distance resulted in up to 54% of tube cuffs placed too high. Mid-tracheal tube placement led to 100% subglottic or supraglottic tracheal tube cuff positions. CONCLUSIONS: All studied cuffed paediatric tracheal tubes have major design flaws potentially leading to airway complications. Tracheal tube manufacturers are urgently asked to improve the design of cuffed paediatric tracheal tubes. Alternative strategies for tracheal tube placement can allow safe tracheal tube placement of uncuffed but not of cuffed tracheal tubes.

Patency of paediatric endotracheal tubes for airway instrumentation.

BACKGROUND: Airway exchange catheters (AEC) and fiberoptic bronchoscopes (FOB) for tracheal intubation are selected so that there is only a minimal gap between their outer and inner diameter of endotracheal tube (ETT) to minimize the risk of impingement during airway instrumentation. This study aimed to test the ease of passage of FOBs and AECs through paediatric ETT of different sizes and from different manufacturers when using current recommendations for dimensional equipment compatibility taken from text books and manufacturers information. METHODS: Twelve different brands of cuffed and uncuffed ETT sized ID 2.5 to 5.0 mm were evaluated in an in vitro set-up. Ease of device passage as well as the locations of an impaired passage within the ETT were assessed. Redundant samples were used for same sized ETT and all measurements were triple-checked in randomized order. RESULTS: In total, 51 paired samples of uncuffed as well as cuffed paediatric ETT were tested. There were substantial differences in the ease of ETT passage concordantly for FOBs and AECs among different manufacturers, but also among the product lines from the same manufacturer for a given ID size. Restriction to passage most frequently was found near the endotracheal tube tip or as a gradually increasing resistance along the ETT shaft. CONCLUSIONS: Current recommendations for dimensional equipment compatibility AECs and FOBs with ETTs do not appear to be completely accurate for all ETT brands available. We recommend that specific equipment combinations always must be tested carefully together before attempting to use them in a patient.

[Better apprehension of errors in the early clinical treatment of the severely injured]. / Fehler in der frühklinischen Schwerverletztenversorgung besser begreifen.

BACKGROUND: Every year preventable adverse events endanger a considerable number of patients. Current guidelines of the Federal Joint Committee require clinical quality management to provide amongst others an independent clinical risk management and a critical incident reporting system (CIRS). Such guidelines increase the pressure to actively deal with errors, even in emergency medicine. Human error is considered to be the main cause of preventable adverse events in high-risk industries, such as aviation. This observation is gladly directly transferred to clinical medicine. OBJECTIVES: This study investigated where the true causes for preventable adverse events during the resuscitation of severely injured patients can be found. METHODS: A non-systematic literature search of the PubMed database was performed. RESULTS: The search identified three recent studies addressing these objectives that revealed human error as the most important cause of preventable adverse events during emergency room resuscitation (88-97%). Errors during resuscitation in the emergency room occur in approximately 10 %. It is striking that such data do not differ greatly from findings described in studies undertaken 20 years ago. One possible explanation might be that the systematic evaluation of medical errors in the emergency room is a weak spot and that too few lessons can be learnt from such incidents. Therefore, this article describes models of error development and outlines methods to collect data for root cause analysis and for clinical risk management. Thus, this review aims at a better understanding of how errors originate and to allow development of strategies to prevent errors from happening again. CONCLUSION: Human error is the most important cause of preventable adverse events during emergency room resuscitation. Presumably, errors occur unintentionally and as a result of situational misjudgment. As such errors have marked consequences on mortality and morbidity of severely injured patients, an extensive risk management is mandatory for the improvement of quality and safety. Appropriate methods to record errors in order to allow a correct root cause analysis according to well-established protocols is a basic prerequisite.

[Comparison of five video laryngoscopes and conventional direct laryngoscopy : Investigations on simple and simulated difficult airways on the intubation trainer]. / Vergleich von fünf Videolaryngoskopen und direkter konventioneller Laryngoskopie : Untersuchung des einfachen und simulierten schwierigen Atemweg am Intubationstrainer.

INTRODUCTION: Securing the airway with a tracheal tube is essential in emergency situations, in the intensive care setting as well as during anesthesia for surgery and other interventions. Current methods of airway assessment are poor screening tests for predicting difficult direct laryngoscopy due to a generally low positive predictive value; therefore, successful endotracheal intubation requires a high level of expertise, regular training and practice and sometimes additional tools. Currently, several video laryngoscopes (VL) with different designs are commercially available and have been investigated in a wide variety of settings. To our knowledge there is no prospective study evaluating and comparing performance among these three groups of VL; therefore, the aim of this study was to compare performance of five VL and conventional direct laryngoscopy in an intubation manikin model, both in a normal and simulated difficult intubation setting. METHODS: In this study 10 residents, 12 senior staff physicians and 5 anesthesia nurses, all experienced in conventional direct laryngoscopy and inexperienced with VL underwent theoretical and hands-on training with all VL lasting 60 min. Afterwards participants performed intubation with all 5 VL and conventional direct laryngoscopy in a randomized sequence using an intubation manikin with normal intubation settings. Thereafter participants performed intubation in a simulated difficult intubation setting using the same intubation manikin with a neck collar to immobilize the cervical spine. In this study, the C-MAC(®) with Macintosh blade size 3, GlideScope(®) size 3, McGrath(®) series 5, King Vision(®) and Airtraq(®) size 2 were used. Time to intubation served as primary outcome and time to glottis visualization, number of intubation attempts, success rate and subjective evaluation of difficulty served as secondary outcomes. RESULTS: In the normal intubation setting, time to intubation ranged from 16.0 s (conventional direct laryngoscopy) to 34.3 s (McGrath). GlideScope and conventional direct laryngoscopy were successful in 100 % followed by C-MAC (96.7 %), Airtraq (88.9 %), King Vision (77.8 %) and McGrath VL (44.4 %). In the simulated difficult intubation setting, time to intubation ranged between 20.3 s (Airtraq) and 26.7 s (McGrath). Success rate with C-MAC was 100 %, followed by GlideScope (96.7 %), Airtraq (85.2 %), conventional direct laryngoscopy (85.2 %), King Vision (81.5 %) and McGrath VL (70.4 %). CONCLUSION: In the manikin with normal intubation setting, conventional direct laryngoscopy using a Macintosh blade was convincing and superior to any VL used in this study. During simulated difficult intubation, a blade with video transmission, such as C-MAC and the GlideScope were superior compared to conventional direct laryngoscopy and any other VL tested.

[Intubation with a tube exchanger on an intubation trainer. Influence of tube tip position on successful intubation]. / Intubation über den Tubuswechsler an einem Intubationstrainer. Einfluss der Tubusspitzenposition auf den Intubationserfolg.

BACKGROUND: Securing the airway using a tube exchanger catheter is an important and useful technique in anesthesia. Its success is mainly hampered by tube tip impingement of laryngeal structures. Advancing the tracheal tube along its normal curvature via a tube exchanger catheter has a high risk of tube tip impingement mainly of right laryngeal structures. The authors achieved successful clinical experience by rotating the tracheal tube 90° anticlockwise (ventral tube tip position) before railroading the tube via a tube exchanger catheter or a fiber optic bronchoscope through the larynx. AIM: The aim of the study was to investigate the influence of the tracheal tube tip position while intubating an airway trainer over a tube exchange catheter. MATERIAL AND METHODS: Volunteer anesthetists with varying years of professional experience were asked to intubate an intubation mannequin (Laerdal Airway Management Trainer) using the orotracheal route with an established tube exchange catheter (Cook Airway Exchange Catheter, 11F). Two different brands of tracheal tubes (Rüsch and Covidien, ID 7.0 mm) were used in a randomized order, each with the tracheal tube tip at first positioned right (90°), then ventrally (0°), left (270°) and finally dorsally (180°), resulting in eight intubation attempts for each participant. To ensure the correct tube tip position the tube was withdrawn before every intubation attempt until the tube tip position was visualized. The oropharnyx, larynx, trachea and tube were sufficiently lubricated with silicon spray (Rüsch Silikospray). The tube and airway exchange catheter size selection were made according to the clinical trial of Loudermilk et al. Successful endotracheal intubation without resistance was recorded for each tube tip position and tracheal tube brand. RESULTS: In total 20 anesthetists (13 consultants and 7 residents) with a median of 9.5 years (range 3-37 years) of professional experience participated in the study. Overall 160 intubation attempts were performed, 2 participants showed no successful intubation attempts at all and 38 out of 160 intubation attempts (23.8 %) were successful. Intubation success with the tracheal tube tip placed ventrally (0°) was 60 % followed by the left (270°) and right (90°) tracheal tube tip positions with 27.5 % and 7.5 % intubation success, respectively. With the tube tip placed dorsally (180°) none of the 40 intubation attempts were successful. Intubation attempts with the Rüsch tube were more successful (28.8 %) than those with the Covidien tube (18.8 %). Placing the tracheal tube tip ventrally, the Rüsch tube was twice as successful as the Covidien tube with 16 (80 %) versus 8 attempts (40 %, p = 0.011). There was no correlation between professional experience and intubation success (p = 0.362). CONCLUSION: Tube insertion via an airway exchange catheter or a fiberoptic bronchoscope is a basic technique in anesthesia. Knowledge about the difficulties and their prevention are essential for every anesthetist. The gap between the airway exchange catheter, the fiber bronchoscope and the tube diameters is one of the major reasons for tube tip impingement. This investigation showed that intubation success via a tube exchange catheter, as investigated in an intubation mannequin, is considerably influenced by the tracheal tube tip position. A 90° anticlockwise rotation, placing the tracheal tube tip ventrally, considerably increased intubation success. This is of particular importance if an anesthesia department has no appropriately sized tube exchange catheters or fiber bronchoscope for every age group of patients.