Richard Schalk

Out-of-hospital airway management by paramedics and emergency physicians using laryngeal tubes

CONCEPT Endotracheal intubation (ETI) is considered to be the gold standard of prehospital airway management. However, ETI requires substantial technical skills and ongoing experience. Because failed prehospital ETI is common and associated with a higher mortality, reliable airway devices are needed to be used by rescuers less experienced in ETI. We prospectively evaluated the feasibility of laryngeal tubes used by paramedics and emergency physicians for out-of-hospital airway management. MATERIAL AND METHODS During a 24-month period, all cases of prehospital use of the laryngeal tube disposable (LT-D) and laryngeal tube suction disposable (LTS-D) within five operational areas of emergency medical services were recorded by a standardised questionnaire. We determined indications for laryngeal tube use, placement success, number of placement attempts, placement time and personal level of experience. RESULTS Of 157 prehospital intubation attempts with the LT-D/LTS-D, 152 (96.8%) were successfully performed by paramedics (n=70) or emergency physicians (n=87). The device was used as initial airway (n=87) or rescue device after failed ETI (n=70). The placement time was < or =45s (n=120), 46-90s (n=20) and >90s (n=7). In five cases the time needed was not specified. The number of placement attempts was one (n=123), two (n=25), three (n=2) and more than three (n=2). The majority of users (61.1%) were relative novices with no more than five previous laryngeal tube placements. CONCLUSION The LT-D/LTS-D represents a reliable tool for prehospital airway management in the hands of both paramedics and emergency physicians. It can be used as an initial tool to secure the airway until ETI is prepared, as a definitive airway by rescuers less experienced with ETI or as a rescue device when ETI has failed.

Complications associated with the prehospital use of laryngeal tubes—A systematic analysis of risk factors and strategies for prevention

OBJECTIVE With the increasing spread of laryngeal tubes (LT) in emergency medicine, complications and side-effects are observed. We sought to identify complications associated with the use of LTs in emergency medicine, and to develop strategies to prevent these incidents. METHODS In a prospective clinical study, all patients who had their airways managed in the field with a LT and who were admitted through the emergency department of the Frankfurt University Hospital during a 6 year period were evaluated using anonymised data collection sheets. A team of experts was available 24/7 and was requested whenever a patient was admitted with a LT in place. This team evaluated the condition of the patients with respect to prehospital airway management and was responsible for further advanced airway management. All complications were analysed, and strategies for prevention developed. RESULTS One hundred eighty nine patients were included and analysed. The initial cuff pressure of the LTs was 10 0 cm H₂O on the median. Complications consisted of significant tongue swelling (n=73; 38.6%), resulting in life-threatening cannot ventilate, cannot intubate scenarios in two patients (1.0%) and the need for surgical tracheostomy in another patient, massive distension of the stomach (n=20, 10.6%) with ventilation difficulties when LTs without gastric drainage were used; malposition of the LT in the piriform sinus (n=1, 0.5%) and significant bleeding from soft tissue injuries (n=4, 2.1%). CONCLUSIONS The prehospital use of LTs may result in severe and even life-threatening complications. Likely, such complications could have been prevented by using gastric drainage and cuff pressure adjustment. Both, prehospital health care providers and emergency department staff should develop a greater awareness of such complications to best avoid them in the future.

Emergency Airway Management in Trauma Patients Using Laryngeal Tube Suction

Abstract Background. Endotracheal intubation (ETI) is considered to be the “gold standard” of prehospital airway management of trauma patients. However, ETI requires substantial technical skills and ongoing experience. Because failed prehospital ETI is common and associated with a higher mortality, reliable airway devices are needed to be used by rescuers who are less experienced in ETI. Objective. To prospectively evaluate the feasibility of the use of laryngeal tubes by paramedics and emergency physicians for out-of-hospital airway management in trauma patients. Methods. During a 40-month period, data for all cases of prehospital use of the laryngeal tube suction disposable (LTS-D) within a large metropolitan area were recorded by a standardized questionnaire. We determined indications for laryngeal tube use, placement success, number of placement attempts, placement time, and personal level of experience. All patients admitted to our institution also underwent in-hospital follow-up. Results. Fifty-six of 57 prehospital intubations attempts with the LTS-D were successfully performed by paramedics (n = 19) or emergency physicians (n = 37) within one (n = 50) or two (n = 6) placement attempts. The device was used as initial airway (n = 27) or rescue device after failed ETI (n = 30). The placement time was ≤45 seconds (n = 42), 46–90 seconds (n = 13), and >90 seconds (n = 1). The majority of users (n = 44) were relative novices with no more than 10 previous laryngeal tube placements on actual patients. Of 33 patients eligible for follow-up, one underwent urgent LTS-D removal and subsequent ETI upon hospital admission, six underwent ETI after primary survey, and 26 underwent both primary and secondary survey or even damage-control surgery with the LTS-D. Conclusion. The LTS-D represents a promising alternative to ETI in the hands of both paramedics and emergency physicians. It can be used as an initial tool to secure the airway until ETI is prepared, as a definitive airway by rescuers less experienced in ETI, or as a rescue device when ETI has failed.

Comparison of the TruView infant EVO2 PCD™ and C-MAC video laryngoscopes with direct Macintosh laryngoscopy for routine tracheal intubation in infants with normal airways.

OBJECTIVE: Videolaryngoscopy has mainly been developed to facilitate difficult airway intubation. However, there is a lack of studies demonstrating this methods efficacy in pediatric patients. The aim of the present study was to compare the TruView infant EVO2 and the C-MAC videolaryngoscope with conventional direct Macintosh laryngoscopy in children with a bodyweight ≤10 kg in terms of intubation conditions and the time to intubation. METHODS: In total, 65 children with a bodyweight ≤10 kg (0-22 months) who had undergone elective surgery requiring endotracheal intubation were retrospectively analyzed. Our database was screened for intubations with the TruView infant EVO2, the C-MAC videolaryngoscope, and conventional direct Macintosh laryngoscopy. The intubation conditions, the time to intubation, and the oxygen saturation before and after intubation were monitored, and demographic data were recorded. Only children with a bodyweight ≤10 kg were included in the analysis. RESULTS: A total of 23 children were intubated using the C-MAC videolaryngoscope, and 22 children were intubated using the TruView EVO2. Additionally, 20 children were intubated using a standard Macintosh blade. The time required for tracheal intubation was significantly longer using the TruView EVO2 (52 sec vs. 28 sec for C-MAC vs. 26 sec for direct LG). However, no significant difference in oxygen saturation was found after intubation. CONCLUSION: All devices allowed excellent visualization of the vocal cords, but the time to intubation was prolonged when the TruView EVO2 was used. The absence of a decline in oxygen saturation may be due to apneic oxygenation via the TruView scope and may provide a margin of safety. In sum, the use of the TruView by a well-trained anesthetist may be an alternative for difficult airway management in pediatric patients.

Disposable laryngeal tube suction: Standard insertion technique versus two modified insertion techniques for patients with a simulated difficult airway

OBJECTIVE The disposable laryngeal tube suction (LTS-D) is a supraglottic airway device that can be used as an alternative to tracheal tube to provide ventilation. We tested the hypothesis that, with a frontal jaw thrust insertion technique (FIT/JT), the rate of correct placement attempts in patients with a simulated difficult airway by means of a rigid cervical immobilization collar could be significantly increased compared to the standard insertion technique (SIT) recommended by the manufacturer. METHODS 70 adult patients undergoing trauma surgery under general anaesthesia had an LTS-D inserted, randomly assigned to the SIT or FIT/JT. In the FIT/JT, the operator was standing in front of the patients head, and forced chin lift to create sufficient retropharyngeal space was performed. The rate of successful tube placements within 180s and with a maximum of two attempts was the main outcome variable. To distinguish between the effects of the frontal approach and the jaw thrust manoeuvre, a third group was studied after completion of the SIT and FIT/JT groups. The standard insertion technique, but with a jaw thrust manoeuvre (SIT/JT), was employed in another 35 consecutive patients. RESULTS Overall placement success was 49% (SIT, 17/35 patients, P<0.001), 91% (SIT/JT, 32/35 patients) and 100% (FIT/JT). The time required for successful insertion was shortest in the FIT/JT group (23±6s), and significantly longer in the SIT/JT (42±29s, P<0.001) and SIT groups (51±29s, P<0.0001). CONCLUSION In anaesthetised patients with a simulated difficult airway created with a rigid cervical collar, the overall LTS-D placement success was significantly higher when a jaw thrust manoeuvre was performed, regardless of the particular technique used to introduce the LTS-D. Therefore, an intense jaw thrust manoeuvre should be performed whenever an LTS-D is being inserted.

A radiographic comparison of human airway anatomy and airway manikins--Implications for manikin-based testing of artificial airways.

OBJECTIVE The aim of this prospective, single-center, observational study was to investigate the accuracy of modeling and reproduction of human anatomical dimensions in manikins by comparing radiographic upper airway measurements of 13 different models with humans. METHODS 13 commonly used airway manikins (male or female anatomy based) and 47 controls (adult humans, 37 male, 10 female) were investigated using a mediosagittal and axial cervical spine CT scan. For anatomical comparison six human upper airway target structures, the following were measured: Oblique diameter of the tongue through the center, horizontal distance between the center point of the tongue and the posterior pharyngeal wall, horizontal distance between the vallecula and the posterior pharyngeal wall, distance of the upper oesophageal orifice length of epiglottis distance at the narrowest part of the trachea. Furthermore, the cross-section of the trachea in axial view and the cross-section of the upper oesophageal orifice in the same section was calculated. All measurements were compared gender specific, if the gender was non-specified with the whole sample. RESULTS None of the included 13 different airway manikins matched anatomy in human controls (n = 47) in all of the six measurements. The Laerdal Airway Management Trainer, however, replicated human airway anatomy at least satisfactorily. CONCLUSION This investigation showed that all of the examined manikins did not replicate human anatomy. Manikins should therefore be selected cautiously, depending on the type of airway securing procedure. Their widespread use as a replacement for in vivo trials in the field of airway management needs to be reconsidered.

Comparative quality analysis of hands-off time in simulated basic and advanced life support following European Resuscitation Council 2000 and 2005 guidelines

Aim To compare hands-off time (HOT) in simulated advanced life support (ALS) following European Resuscitation Council (ERC) 2005 guidelines and ERC 2000 and to provide quantitative data on workflow. Subjects and Methods Observations with 18 professional paramedics, performing 39 megacodes (mega-code training; MCT) were videotaped during ALS re-certification. Teams were randomly assigned to train according to ERC 2000 or ERC 2005. HOT, hands-off intervals (HOI) and other variables describing interventions and workflow were analysed. Results In group ERC 2000 17±3 HOI appeared with a mean duration of 17.5±10.8 s (mean±SD). Overall HOT was 382±47 s, equivalent to a mean hands-off fraction (HOF) of 0.45±0.05. 15±5 ventilation-free intervals (VFI) were observed, with a mean duration of 21±10 s. In contrast after ERC 2005 variables resulted in 18±3 HOI with a mean duration of 10.0±4.0 s (p<0.001 vs ERC 2000), overall HOT 196±33 s (HOF 0.23±0.04; p<0.001), 24±12 VFI with a duration of 24±7 s (p<0.05). The first HOI lasted for 60.4±33.1 s in ERC 2000 and 17.6±4.3 s in ERC 2005 (p<0.001). In ERC 2000 6.1±2.6 interruptions for two bag/mask ventilations (BMV) lasted for 5.4±0.8 s, whereas in ERC 2005 9.6±3.1 interruptions for two BMV took 6.5±2.2 s (p<0.001). In both groups HOI were used thoroughly for basic life support/ALS-based interventions. Conclusion The application of ERC guidelines of 2005 markedly reduced the first HOI and mean duration of HOI at the cost of delayed secure airway management and ECG analysis in this MCT model.

Laryngeal tube suction for airway management during in-hospital emergencies

OBJECTIVE: The role of supraglottic airway devices in emergency airway management is highlighted in international airway management guidelines. We evaluated the application of the new generation laryngeal tube suction (LTS-II/LTS-D) in the management of in-hospital unexpected difficult airway and cardiopulmonary resuscitation. METHODS: During a seven-year period, patients treated with a laryngeal tube who received routine anesthesia and had an unexpected difficult airway (Cormack Lehane Grade 3-4), who underwent cardiopulmonary resuscitation, or who underwent cardiopulmonary resuscitation outside the operating room and had a difficult airway were evaluated. Successful placement of the LTS II/LTS-D, sufficient ventilation, time to placement, number of placement attempts, stomach content, peripheral oxygen saturation/end-tidal carbon dioxide development (SpO2/etCO2) over 5 minutes, subjective overall assessment and complications were recorded. RESULTS: In total, 106 adult patients were treated using an LTS-II/LTS-D. The main indication for placement was a difficult airway (75%, n=80), followed by cardiopulmonary resuscitation (25%, n=26) or an overlap between both (18%, n=19). In 94% of patients (n=100), users placed the laryngeal tube during the first attempt. In 93% of patients (n=98), the tube was placed within 30 seconds. A significant increase in SpO2 from 97% (0-100) to 99% (5-100) was observed in the whole population and in cardiopulmonary resuscitation patients. The average initial etCO2 of 39.5 mmHg (0-100 mmHg) decreased significantly to an average of 38.4 mmHg (10-62 mmHg) after 5 minutes. A comparison of cardiopulmonary resuscitation patients with non-cardiopulmonary resuscitation patients regarding gastric contents showed no significant difference. CONCLUSIONS: LTS-D/LTS-II use for in-hospital unexpected difficult airway management provides a secure method for primary airway management until other options such as video laryngoscopy or fiber optic intubation become available.