Pressure in the cuffs of tracheal tubes at altitude.
Smith R P R,McArdle B H
Anaesthesia
Pressures in the cuffs of three commonly used tracheal tubes (Portex Profile Softseal, Mallinckrodt Lo-Contour and Mallinckrodt Hi-Contour, size 8.0 mm and 9.0 mm internal diameter), inflated with air, were measured during simulated ascents in an altitude chamber to 10 000 ft. There was no detectable difference in performance between sizes for each type of tracheal tube. When averaged over the two sizes for each type of tube, cuff pressure reached the critical perfusion pressure 50 cmH2O (37 mmHg) for tracheal mucosa at a higher altitude in the Portex Profile Softseal (2837 ft, 95% CI 2488-3186 ft) than in the Mallinckrodt Lo-Contour (2128 ft, 95% CI 1779-2476 ft; p = 0.02) and Mallinckrodt Hi-Contour (1820 ft; 95% CI 1471-2168 ft; p = 0.002) tracheal tubes. When the cuffs of the 9.0-mm tracheal tubes were inflated with saline, much smaller increases in pressure were measured with increasing altitude, although inflation of the cuffs with saline was technically difficult. Commonly used tracheal tubes with air-inflated cuffs can be used for aeromedical retrieval, but air should be evacuated from the cuffs after increases in altitude of as little as 2000-3000 ft.
10.1046/j.1365-2044.2002.02464.x
Endotracheal tube intracuff pressure during helicopter transport.
Bassi Marco,Zuercher Mathias,Erne Jean-Jacques,Ummenhofer Wolfgang
Annals of emergency medicine
STUDY OBJECTIVE:We evaluate changes in endotracheal tube intracuff pressures among intubated patients during aeromedical transport. We determine whether intracuff pressures exceed 30 cm H(2)O during aeromedical transport. METHODS:During a 12-month period, a helicopter-based rescue team prospectively recorded intracuff pressures of mechanically ventilated patients before takeoff and as soon as the maximum flight level was reached. With a commercially available pressure manometer, intracuff pressure was adjusted to < or =25 cm H(2)O before loading of the patient. The endpoint of our investigation was the increase of endotracheal tube cuff pressure during helicopter transport. RESULTS:Among 114 intubated patients, mean altitude increase was 2,260 feet (95% confidence interval [CI] 2,040 to 2,481 feet; median 2,085 feet; interquartile range [IQR] 1,477.5 to 2,900 feet). Mean flight time was 14.8 minutes (95% CI 13.1 to 16.4 minutes; median 13.5 minutes; IQR 10 to 16.1 minutes). Intracuff pressure increased from 28.7 cm H(2)O (95% CI 27.0 to 30.4 cm H(2)O [median 25 cm H(2)O; IQR 25 to 30 cm H(2)O]) to 62.6 cm H(2)O (95% CI 58.8 to 66.5 cm H(2)O; median 58; IQR 48 to 72 cm H(2)O). At cruising altitude, 98% of patients had intracuff pressures > or =30 cm H(2)O, 72% had intracuff pressures > or =50 cm H(2)O, and 20% even had intracuff pressures > or =80 cm H(2)O. CONCLUSION:Endotracheal cuff pressure during transport frequently exceeded 30 cm H(2)O during aeromedical transport. Hospital and out-of-hospital practitioners should measure and adjust endotracheal cuff pressures before and during flight.
10.1016/j.annemergmed.2010.01.025
Inhalation of expiratory droplets in aircraft cabins.
Gupta J K,Lin C-H,Chen Q
Indoor air
UNLABELLED:Airliner cabins have high occupant density and long exposure time, so the risk of airborne infection transmission could be high if one or more passengers are infected with an airborne infectious disease. The droplets exhaled by an infected passenger may contain infectious agents. This study developed a method to predict the amount of expiratory droplets inhaled by the passengers in an airliner cabin for any flight duration. The spatial and temporal distribution of expiratory droplets for the first 3 min after the exhalation from the index passenger was obtained using the computational fluid dynamics simulations. The perfectly mixed model was used for beyond 3 min after the exhalation. For multiple exhalations, the droplet concentration in a zone can be obtained by adding the droplet concentrations for all the exhalations until the current time with a time shift via the superposition method. These methods were used to determine the amount of droplets inhaled by the susceptible passengers over a 4-h flight under three common scenarios. The method, if coupled with information on the viability and the amount of infectious agent in the droplet, can aid in evaluating the infection risk. PRACTICAL IMPLICATIONS:The distribution of the infectious agents contained in the expiratory droplets of an infected occupant in an indoor environment is transient and non-uniform. The risk of infection can thus vary with time and space. The investigations developed methods to predict the spatial and temporal distribution of expiratory droplets, and the inhalation of these droplets in an aircraft cabin. The methods can be used in other indoor environments to assess the relative risk of infection in different zones, and suitable measures to control the spread of infection can be adopted. Appropriate treatment can be implemented for the zone identified as high-risk zones.
10.1111/j.1600-0668.2011.00709.x
[Medical Emergency Preparedness in offshore wind farms : New challenges in the german north and baltic seas].
Stuhr M,Dethleff D,Weinrich N,Nielsen M,Hory D,Kowald B,Seide K,Kerner T,Nau C,Jürgens C
Der Anaesthesist
BACKGROUND:Offshore windfarms are constructed in the German North and Baltic Seas. The off-coast remoteness of the windfarms, particular environmental conditions, limitations in offshore structure access, working in heights and depths, and the vast extent of the offshore windfarms cause significant challenges for offshore rescue. Emergency response systems comparable to onshore procedures are not fully established yet. Further, rescue from offshore windfarms is not part of the duty of the German Maritime Search and Rescue Organization or SAR-Services due to statute and mandate reasons. Scientific recommendations or guidelines for rescue from offshore windfarms are not available yet. The present article reflects the current state of medical care and rescue from German offshore windfarms and related questions. The extended therapy-free interval until arrival of the rescue helicopter requires advanced first-aid measures as well as improved first-aider qualification. Rescue helicopters need to be equipped with a winch system in order to dispose rescue personnel on the wind turbines, and to hoist-up patients. For redundancy reasons and for conducting rendezvous procedures, adequate sea-bound rescue units need to be provided. In the light of experiences from the offshore oil and gas industry and first offshore wind analyses, the availability of professional medical personnel in offshore windfarms seems advisible. Operational air medical rescue services and specific offshore emergency reaction teams have established a powerful rescue chain. Besides the present development of medical standards, more studies are necessary in order to place the rescue chain on a long-term, evidence-based groundwork. A central medical offshore registry may help to make a significant contribution at this point.
10.1007/s00101-016-0154-7
Managing endotracheal tube cuff pressure at altitude: a comparison of four methods.
Britton Tyler,Blakeman Thomas C,Eggert John,Rodriquez Dario,Ortiz Heather,Branson Richard D
The journal of trauma and acute care surgery
BACKGROUND:Ascent to altitude results in the expansion of gases in closed spaces. The management of overinflation of the endotracheal tube (ETT) cuff at altitude is critical to prevent mucosal injury. METHODS:We continuously measured ETT cuff pressures during a Critical Care Air Transport Team training flight to 8,000-ft cabin pressure using four methods of cuff pressure management. ETTs were placed in a tracheal model, and mechanical ventilation was performed. In the control ETT, the cuff was inflated to 20 mm Hg to 22 mm Hg and not manipulated. The manual method used a pressure manometer to adjust pressure at cruising altitude and after landing. A PressureEasy device was connected to the pilot balloon of the third tube and set to a pressure of 20 mm Hg to 22 mm Hg. The final method filled the balloon with 10 mL of saline. Both size 8.0-mm and 7.5-mm ETT were studied during three flights. RESULTS:In the control tube, pressure exceeded 70 mm Hg at cruising altitude. Manual management corrected for pressure at altitude but resulted in low cuff pressures upon landing (<10 mm Hg). The PressureEasy reduced the pressure change to a maximum of 36 mm Hg, but on landing, cuff pressures were less than 15 mm Hg. Saline inflation ameliorated cuff pressure changes at altitude, but initial pressures were 40 mm Hg. CONCLUSION:None of the three methods using air inflation managed to maintain cuff pressures below those associated with tracheal damage at altitude or above pressures associated with secretion aspiration during descent. Saline inflation minimizes altitude-related alteration in cuff pressure but creates excessive pressures at sea level. New techniques need to be developed.
10.1097/TA.0000000000000339
Endotracheal tube cuff pressure before, during, and after fixed-wing air medical retrieval.
Brendt Peter,Schnekenburger Marc,Paxton Karen,Brown Anthony,Mendis Kumara
Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors
Abstract Background. Increased endotracheal tube (ETT) cuff pressure is associated with compromised tracheal mucosal perfusion and injuries. No published data are available for Australia on pressures in the fixed-wing air medical retrieval setting. Objective. After introduction of a cuff pressure manometer (Mallinckrodt, Hennef, Germany) at the Royal Flying Doctor Service (RFDS) Base in Dubbo, New South Wales (NSW), Australia, we assessed the prevalence of increased cuff pressures before, during, and after air medical retrieval. Methods. This was a retrospective audit in 35 ventilated patients during fixed-wing retrievals by the RFDS in NSW, Australia. Explicit chart review of ventilated patients was performed for cuff pressures and changes during medical retrievals with pressurized aircrafts. Pearson correlation was calculated to determine the relation of ascent and ETT cuff pressure change from ground to flight level. Results. The mean (± standard deviation) of the first ETT cuff pressure measurement on the ground was 44 ± 20 cmH2O. Prior to retrieval in 11 patients, the ETT cuff pressure was >30 cmH2O and in 11 patients >50 cmH2O. After ascent to cruising altitude, the cuff pressure was >30 cmH2O in 22 patients and >50 cmH2O in eight patients. The cuff pressure was reduced 1) in 72% of cases prior to take off and 2) in 85% of cases during flight, and 3) after landing, the cuff pressure increased in 85% of cases. The correlation between ascent in cabin altitude and ETT cuff pressure was r = 0.3901, p = 0.0205. Conclusions. The high prevalence of excessive cuff pressures during air medical retrieval can be avoided by the use of cuff pressure manometers. Key words: cuff pressure; air medical retrieval; prehospital.
10.3109/10903127.2012.744787
Advanced airway management in an anaesthesiologist-staffed Helicopter Emergency Medical Service (HEMS): A retrospective analysis of 1047 out-of-hospital intubations.
Piegeler Tobias,Neth Philippe,Schlaepfer Martin,Sulser Simon,Albrecht Roland,Seifert Burkhardt,Spahn Donat R,Ruetzler Kurt
Resuscitation
INTRODUCTION:Airway management in the out-of-hospital emergency setting is challenging. Failed and even prolonged airway management is associated with serious clinical consequences, such as desaturation, bradycardia, airway injuries, or aspiration. The overall success rate of tracheal intubation ranges between 77% and 99%, depending on the level of experience of the provider. Therefore, advanced airway management should only be performed by highly-skilled and experienced providers. METHODS:9765 patients were treated in the out-of-hospital emergency setting by the anaesthesiologist-staffed Helicopter Emergency Medical Services (HEMS) between 2002 and 2014. Patients successfully intubated upon the first attempt were compared to patients who required more than one intubation attempts regarding several potential confounding factors such as age, gender, on-going CPR, NACA Score, initial GCS, prior administration of anaesthetic drugs, neuromuscular blocking agents, and vasopressors. RESULTS:1573 out of 9765 patients (16.1%) required advanced airway management. 459 patients had already been intubated upon arrival of the HEMS, whereas 1114 patients (11.4%) underwent advanced airway management by the HEMS physician. 67 patients had to be excluded. Data for the remaining 1047 patients (790 males and 257 females) were analyzed further. Primary use of an alternative airway device was reported in 59 patients (5.6%), whereas 988 patients (94.4%) underwent laryngoscopy-guided tracheal intubation. 952 patients (96.4%) could be intubated upon the first attempt and overall intubation success was 99.5% (983 out of 988). CONCLUSION:Our study demonstrates that HEMS physicians performed airway management frequently and that both the first attempt as well as the overall success rate of tracheal intubation was high. Together with the fact that all failed and difficult intubations were successfully recognized and handled and that no surgical airway had to be established, the current study once more underlines the importance of proper training of HEMS care providers regarding airway management.
10.1016/j.resuscitation.2016.04.020
Efficacy of topical agents for prevention of postoperative sore throat after single lumen tracheal intubation: a Bayesian network meta-analysis.
Canadian journal of anaesthesia = Journal canadien d'anesthesie
BACKGROUND:The optimal choice of prophylactic drugs to decrease postoperative sore throat is unclear. The objective of this network meta-analysis (NMA) was to compare and rank 11 topical agents used to prevent postoperative sore throat. METHODS:Various databases were searched independently for randomized-controlled trials (RCTs) comparing topical agents used for the prevention of postoperative sore throat. Inclusion criteria were parallel group studies comparing intervention with active or inactive control and reporting postoperative sore throat. The primary outcome was postoperative sore throat at 24 hr. Secondary outcomes were early sore throat at 4-6 hr, cough, and hoarseness at 24 hr. RESULTS:Evidence was synthesized from 70 RCTs reporting 7,141 patients. Topical application of lidocaine, corticosteroids, ketamine, magnesium, benzydamine, water-based lubricant, and liquorice applied along the tracheal tube, to the tracheal tube cuff, gargled or sprayed were compared with intracuff air and each other. Bayesian NMA showed that magnesium (odds ratio [OR], 0.10; 95% credible interval [CrI], 0.03 to 0.26), liquorice (OR, 0.14; 95% CrI, 0.03 to 0.55), and steroid application (OR, 0.11; 95% CrI, 0.06 to 0.22) most effectively prevented postoperative sore throat at 24 hr. Topical lidocaine was the least effective intervention. CONCLUSION:Topical application of magnesium followed by liquorice and corticosteroids most effectively prevented postoperative sore throat 24 hr after endotracheal intubation.
10.1007/s12630-020-01792-4
Battlefield tracheal intubation training using virtual simulation: a multi center operational assessment of video laryngoscope technology.
Boedeker Ben H,Boedeker Kirsten A,Bernhagen Mary A,Miller David J,Lacy Timothy
Studies in health technology and informatics
Airway management is an essential skill in providing care in trauma situations. The video laryngoscope is a tool which offers improvement in teaching airway management skills and in managing airways of trauma patients on the far forward battlefield. An Operational Assessment (OA) of videolaryngoscope technology for medical training and airway management was conducted by the Center for Advanced Technology and Telemedicine (at the University of Nebraska Medical Center, Omaha, NE) for the US Air Force Modernization Command to validate this technology in the provision of Out of OR airway management and airway management training in military simulation centers. The value for both the training and performance of intubations was highly rated and the majority of respondents indicated interest in having a video laryngoscope in their facility.
First-pass intubation success rate during rapid sequence induction of prehospital anaesthesia by physicians versus paramedics.
Peters Joost,van Wageningen Bas,Hendriks Ilze,Eijk Ruud,Edwards Michael,Hoogerwerf Nico,Biert Jan
European journal of emergency medicine : official journal of the European Society for Emergency Medicine
INTRODUCTION:Endotracheal intubation is a frequently performed procedure for securing the airway in critically injured or ill patients. Performing prehospital intubation may be challenging and intubation skills vary. We reviewed the first-attempt tracheal intubation success rate in a Dutch prehospital setting. PATIENTS AND METHODS:We studied our database for all intubations performed by helicopter emergency medical services (HEMS) physicians, HEMS nurse and ambulance paramedics under HEMS supervision between January 2007 and July 2012. The primary outcome was success rate, number of intubation attempts and alternative airway procedures. RESULTS:In all, 1399 patients were in need of a secured airway. In 571 (40.8%) of these cases, ambulance paramedics made a first intubation attempt under HEMS supervision. If necessary, rapid sequence induction medication was administered. In comparable patient groups, the first intubation success rate was significantly lower in ambulance paramedics compared with helicopter physicians (46.4 vs. 84.5%, P<0.0001). The overall physician intubation success rate was 98.4% after one or more intubation attempts. In 19 cases, a surgical airway was created and in three cases an alternative ventilation method was used. CONCLUSION:Prehospital intubations had a significantly higher success rate when performed by helicopter physicians. We promote a low threshold for HEMS deployment in cases of a potentially compromised airway.
10.1097/MEJ.0000000000000161
Difficult Intubation Factors in Prehospital Rapid Sequence Intubation by an Australian Helicopter Emergency Medical Service.
Burns Brian,Habig Karel,Eason Hilary,Ware Sandra
Air medical journal
OBJECTIVE:Prehospital rapid sequence intubation (RSI) of critically ill trauma patients is a high-risk procedure that may be associated with an increased rate of severe complications such as failed intubation, failure of oxygenation, hypoxia, hypotension, or need for surgical airway. The objective of this study was to describe the factors associated with difficult intubation in prehospital RSI as defined by more than a single look at laryngoscopy to achieve tracheal intubation. METHODS:This is an observational study using prospectively collected data. RESULTS:Four hundred forty-three RSIs were performed. Paramedics were the initial laryngoscopist in 290 (65.5%). First-look laryngoscopy resulted in successful tracheal intubation (TI) in 372 (84.0%) (95% confidence interval, 80.3%-87.1%). Intubation was achieved on second look at laryngoscopy in 58 (13.1%). "First-pass" TI was achieved in 394 (88.9%). Overall, successful TI was achieved in 438 (98.9%) (95% confidence interval, 97.4%-99.5%). Complications occurred in 116 (26.2%), with desaturation the commonest in 77 (17.4%). CONCLUSION:Factors associated with more than 1 look at laryngoscopy before TI included paramedic laryngoscopist and the presence of at least 1 of the following indicators: blood/vomitus in the airway, limited mouth opening, and limited neck movement. Trauma to face/neck, obese body habitus, C-spine precautions, cricoid pressure, midline stabilization, and intubation on the ground did not influence the level of difficulty encountered.
10.1016/j.amj.2015.10.002
Intubation Success in Critical Care Transport: A Multicenter Study.
Reichert Ryan J,Gothard Megan,Gothard M David,Schwartz Hamilton P,Bigham Michael T
Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors
INTRODUCTION:Tracheal intubation (TI) is a lifesaving critical care skill. Failed TI attempts, however, can harm patients. Critical care transport (CCT) teams function as the first point of critical care contact for patients being transported to tertiary medical centers for specialized surgical, medical, and trauma care. The Ground and Air Medical qUality in Transport (GAMUT) Quality Improvement Collaborative uses a quality metric database to track CCT quality metric performance, including TI. We sought to describe TI among GAMUT participants with the hypothesis that CCT would perform better than other prehospital TI reports and similarly to hospital TI success. METHODS:The GAMUT Database is a global, voluntary database for tracking consensus quality metric performance among CCT programs performing neonatal, pediatric, and adult transports. The TI-specific quality metrics are "first attempt TI success" and "definitive airway sans hypoxia/hypotension on first attempt (DASH-1A)." The 2015 GAMUT Database was queried and analysis included patient age, program type, and intubation success rate. Analysis included simple statistics and Pearson chi-square with Bonferroni-adjusted post hoc z tests (significance = p < 0.05 via two-sided testing). RESULTS:Overall, 85,704 patient contacts (neonatal n [%] = 12,664 [14.8%], pediatric n [%] = 28,992 [33.8%], adult n [%] = 44,048 [51.4%]) were included, with 4,036 (4.7%) TI attempts. First attempt TI success was lowest in neonates (59.3%, 617 attempts), better in pediatrics (81.7%, 519 attempts), and best in adults (87%, 2900 attempts), p < 0.001. Adult-focused CCT teams had higher overall first attempt TI success versus pediatric- and neonatal-focused teams (86.9% vs. 63.5%, p < 0.001) and also in pediatric first attempt TI success (86.5% vs. 75.3%, p < 0.001). DASH-1A rates were lower across all patient types (neonatal = 51.9%, pediatric = 74.3%, adult = 79.8%). CONCLUSIONS:CCT TI is not uncommon, and rates of TI and DASH-1A success are higher in adult patients and adult-focused CCT teams. TI success rates are higher in CCT than other prehospital settings, but lower than in-hospital success TI rates. Identifying factors influencing TI success among high performers should influence best practice strategies for TI.
10.1080/10903127.2017.1419324
Comparing the McGrath Mac Video Laryngoscope and Direct Laryngoscopy for Prehospital Emergency Intubation in Air Rescue Patients: A Multicenter, Randomized, Controlled Trial.
Kreutziger Janett,Hornung Sonja,Harrer Clemens,Urschl Wilhelm,Doppler Reinhard,Voelckel Wolfgang G,Trimmel Helmut
Critical care medicine
OBJECTIVES:Tracheal intubation in prehospital emergency care is challenging. The McGrath Mac Video Laryngoscope (Medtronic, Minneapolis, MN) has been proven to be a reliable alternative for in-hospital airway management. This trial compared the McGrath Mac Video Laryngoscope and direct laryngoscopy for the prehospital setting. DESIGN:Multicenter, prospective, randomized, controlled equivalence trial. SETTING:Oesterreichischer Automobil- und Touring Club (OEAMTC) Helicopter Emergency Medical Service in Austria, 18-month study period. PATIENTS:Five-hundred fourteen adult emergency patients (≥ 18 yr old). INTERVENTIONS:Helicopter Emergency Medical Service physicians followed the institutional algorithm, comprising a maximum of two tracheal intubation attempts with each device, followed by supraglottic, then surgical airway access in case of tracheal intubation failure. No restrictions were given for tracheal intubation indication. MEASUREMENTS MAIN RESULTS:The Primary outcome was the rate of successful tracheal intubation; equivalence range was ± 6.5% of success rates. Secondary outcomes were the number of attempts to successful tracheal intubation, time to glottis passage and first end-tidal CO2 measurement, degree of glottis visualization, and number of problems. The success rate for the two devices was equivalent: direct laryngoscopy 98.5% (254/258), McGrath Mac Video Laryngoscope 98.1% (251/256) (difference, 0.4%; 99% CI, -2.58 to 3.39). There was no statistically significant difference with regard to tracheal intubation times, number of attempts or difficulty. The view to the glottis was significantly better, but the number of technical problems was increased with the McGrath Mac Video Laryngoscope. After a failed first tracheal intubation attempt, immediate switching of the device was significantly more successful than after the second attempt (90.5% vs 57.1%; p = 0.0003), regardless of the method. CONCLUSIONS:Both devices are equivalently well suited for use in prehospital emergency tracheal intubation of adult patients. Switching the device following a failed first tracheal intubation attempt was more successful than a second attempt with the same device.
10.1097/CCM.0000000000003918