Airway management by physicians wearing anti-chemical warfare gear: comparison between laryngeal mask airway and endotracheal intubation

Orotracheal tube versus supraglottic devices in biological, chemical and radiological disasters: meta-analysis in manikin-based studies

OBJECTIVE

To compare the mean time of orotracheal intubation and insertion of supraglottic airway devices, considering healthcare providers wearing waterproof overall, gloves, boots, eye protection and mask at the Chemical, Biological, Radiological and Nuclear context in simulation setting.

METHODS

Six databases were searched. The selected studies were put in a pool of results using a random-effects meta-analysis, with standardized mean differences and calculation of 95% confidence intervals.

RESULTS

Nine observational studies were included. Regarding reducing time to provide ventilatory support, subgroup analyses were made. The emergency setting subgroup: -12.97 [-16.11; -9.83]; I2 = 64%. The surgery setting subgroup: -14.96 [-18.65; -11.27]; I2 = 75%. Another analysis was made by reproductive methodology subgroups. Ophir's subgroup: -15.70 [-17.04; -14.37]; I2 = 0%. All meta-analyses had orotracheal tube as comparator.

CONCLUSION

Moderate level of evidence was in favor of insertion of supraglottic devices because of fast application.

Systematic review and meta-analysis comparing ventilatory support in chemical, biological and radiological emergencies

Objective:

to compare the mean development time of the techniques of direct laryngoscopy and insertion of supraglottic devices; and to evaluate the success rate in the first attempt of these techniques, considering health professionals wearing specific personal protective equipment (waterproof overalls; gloves; boots; eye protection; mask).

Method:

meta-analysis with studies from LILACS, MEDLINE, CINAHL, Cochrane, Scopus and Web of Science. The keywords were the following: personal protective equipment; airway management; intubation; laryngeal masks.

Results:

in the “reduction of the time of the procedures” outcome, the general analysis of the supraglottic devices in comparison with the orotracheal tube initially presented high heterogeneity of the data (I²= 97%). Subgroup analysis had an impact on reducing heterogeneity among the data. The “laryngeal mask as a guide for orotracheal intubation” subgroup showed moderate heterogeneity (I²= 74%). The “2^ndgeneration supraglottic devices” subgroup showed homogeneity (I²= 0%). All the meta-analyses favored supraglottic devices. In the “success in the first attempt” outcome, moderate homogeneity was found (I²= 52%), showing a higher proportion of correct answers for supraglottic devices.

Conclusion:

in the context of chemical, biological or radiological disaster, the insertion of the supraglottic device proved to be faster and more likely to be successful by health professionals. PROSPERO record (CRD42019136139).

Airway Management in Disaster Response: A Manikin Study Comparing Direct and Video Laryngoscopy for Endotracheal Intubation by Prehospital Providers in Level C Personal Protective Equipment

Introduction Airway management is one of many challenges that medical providers face in disaster response operations. The use of personal protective equipment (PPE), in particular, was found to be associated with higher failure rates and a prolonged time to achieve airway control. Hypothesis/Problem The objective of this study was to determine whether video laryngoscopy could facilitate the performance of endotracheal intubation by disaster responders wearing Level C PPE.

METHODS

In this prospective, randomized, crossover study, a convenience sample of practicing prehospital providers were recruited. Following standardized training in PPE use and specific training in the use of airway devices, subjects in Level C PPE were observed while performing endotracheal intubation on a stock airway in a Laerdal Resusci-Anne manikin system (Laerdal Medical; Stavanger, Norway) using one of three laryngoscopic devices in randomized order: a Macintosh direct laryngoscope (Welch Allyn Inc.; New York USA), a GlideScope Ranger video laryngoscope (Verathon Medical; Bothell, Washington USA), and a King Vision video laryngoscope (King Systems; Noblesville, Indiana USA). The primary outcome was time to intubation (TTI), and the secondary outcome was participant perception of the ease of use for each device.

RESULTS

A total of 20 prehospital providers participated in the study: 18 (90%) paramedics and two (10%) Emergency Medical Technicians-Cardiac. Participants took significantly longer when using the GlideScope Ranger [35.82 seconds (95% CI, 32.24-39.80)] to achieve successful intubation than with the Macintosh laryngoscope [25.69 seconds (95% CI, 22.42-29.42); adj. P<.0001] or the King Vision [29.87 seconds (95% CI, 26.08-34.21); adj. P=.033], which did not significantly differ from each other (adj. P=.1017). Self-reported measures of satisfaction evaluated on a 0% to 100% visual analog scale (VAS) identified marginally greater subject satisfaction with the King Vision [86.7% (SD=76.4-92.9%)] over the GlideScope Ranger [73.0% (SD=61.9-81.8%); P=.04] and the Macintosh laryngoscope [69.9% (SD=57.9-79.7%); P=.05] prior to adjustment for multiplicity. The GlideScope Ranger and the Macintosh laryngoscope did not differ themselves (P=.65), and the differences were not statistically significant after adjustment for multiplicity (adj. P=.12 for both comparisons).

CONCLUSION

Use of video laryngoscopes by prehospital providers in Level C PPE did not result in faster endotracheal intubation than use of a Macintosh laryngoscope. The King Vision video laryngoscope, in particular, performed at least as well as the Macintosh laryngoscope and was reported to be easier to use. Yousif S , Machan JT , Alaska Y , Suner S . Airway management in disaster response: a manikin study comparing direct and video laryngoscopy for endotracheal intubation by prehospital providers in Level C personal protective equipment. Prehosp Disaster Med. 2017;32(4):352-356.

Intubation performance using different laryngoscopes while wearing chemical protective equipment: a manikin study

OBJECTIVES

This study aimed to compare visualisation of the vocal cords and performance of intubation by anaesthetists using four different laryngoscopes while wearing full chemical protective equipment.

SETTING

Medical simulation center of a university hospital, department of anaesthesiology.

PARTICIPANTS

42 anaesthetists (15 females and 27 males) completed the trial. The participants were grouped according to their professional education as anaesthesiology residents with experience of <2 years or <5 years, or as anaesthesiology specialists with experience of >5 years.

INTERVENTIONS

In a manikin scenario, participants performed endotracheal intubations with four different direct and indirect laryngoscopes (Macintosh (MAC), Airtraq (ATQ), Glidescope (GLS) and AP Advance (APA)), while wearing chemical protective gear, including a body suit, rubber gloves, a fire helmet and breathing apparatus.

PRIMARY AND SECONDARY OUTCOME MEASURES

With respect to the manikin, setting time to complete 'endotracheal intubation' was defined as primary end point. Glottis visualisation (according to the Cormack-Lehane score (CLS) and impairments caused by the protective equipment, were defined as secondary outcome measures.

RESULTS

The times to tracheal intubation were calculated using the MAC (31.4 s; 95% CI 26.6 to 36.8), ATQ (37.1 s; 95% CI 28.3 to 45.9), GLS (35.4 s; 95% CI 28.7 to 42.1) and APA (23.6 s; 95% CI 19.1 to 28.1), respectively. Intubation with the APA was significantly faster than with all the other devices examined among the total study population (p<0.05). A significant improvement in visualisation of the vocal cords was reported for the APA compared with the GLS.

CONCLUSIONS

Despite the restrictions caused by the equipment, the anaesthetists intubated the manikin successfully within adequate time. The APA outperformed the other devices in the time to intubation, and it has been evaluated as an easily manageable device for anaesthetists with varying degrees of experience (low to high), providing good visualisation in scenarios that require the use of chemical protective equipment.

Intubation Efficiency and Perceived Ease of Use of Video Laryngoscopy vs Direct Laryngoscopy While Wearing HazMat PPE: A Preliminary High-fidelity Mannequin Study

INTRODUCTION

Management of contaminated patients in the decontamination corridor requires the use of hazardous material (HazMat) personal protective equipment (PPE). Previous studies have demonstrated that HazMat PPE may increase the difficulty of airway management. This study compared the efficiency of video laryngoscopy (VL) with traditional direct laryngoscopy (DL) during endotracheal intubation (ETI) while wearing HazMat PPE.

METHODS

Post-graduate year (PGY) 1-3 Emergency Medicine residents were randomized to VL or DL while wearing encapsulating PPE. Video laryngoscopy was performed using the GlideScope Cobalt AVL video laryngoscope. The primary outcome measure was time to successful ETI in a high-fidelity simulation mannequin. Three time points were utilized in the analysis: Time 0 (blade at lips), Time 1 (blade removed from lips after endotracheal tube placement), and Time 2 (bag valve mask [BVM] attached to endotracheal tube). Secondary outcome measures were perceived ease of use and feasibility of VL and DL ETI modalities.

RESULTS

Twenty-one of 23 (91.3%) eligible residents participated. Mean time to ETI was 10.0 seconds (SD=5.3 seconds) in the DL group and 7.8 seconds (SD=3.0 seconds) in the VL group (P=.081). Mean times from blade insertion until BVM attachment were 17.4 seconds (SD=6.0 seconds) and 15.6 seconds (SD=4.6 seconds), respectively (P=.30). There were no unsuccessful intubation attempts. Seventeen out of 20 participants (85.0%) perceived VL to be easier to use when performing ETI in PPE. Twelve out of 20 participants (60%) perceived DL to be more feasible in an actual HazMat scenario.

CONCLUSION

The time to successful ETI was not significantly different between VL and DL. Video laryngoscopy had a greater perceived ease of use, but DL was perceived to be more feasible for use in actual HazMat situations. These findings suggest that both DL and VL are reasonable modalities for use in HazMat situations, and the choice of modality could be based on the clinical situation and provider experience.

Airway control in case of a mass toxicological event: superiority of second-generation supraglottic airway devices

INTRODUCTION

Early respiratory support and airway (AW) control with endotracheal intubation (ETI) are crucial in mass toxicology events and must be performed while wearing chemical personal protective equipment (C-PPE).

AIM

The aim of this study is to evaluate the efficiency of AW control by using second-generation supraglottic AW devices (SADs) as compared with ETI and first-generation SAD while wearing C-PPE.

METHODS

This is a randomized crossover trial involving 117 medical practitioners. Four AW management devices were examined: endotracheal tube, the first-generation SAD, laryngeal mask AW unique and 2 second-generation SAD, the laryngeal tube suction disposable, and supreme laryngeal mask AW (SLMA). Primary end point measured were success or failure, number of attempts, and time needed to achieve successful device insertion. Secondary end point was a subjective appraisal of the AW devices by study population.

RESULTS

More attempts were required to achieve AW control with endotracheal tube, with and without C-PPE (P<.001). Time to achieve AW control with ETI was, on average, 88% longer than required with other devices and improved with practice. The mean times to achieve an AW were longer when operators were equipped with C-PPE as compared with standard clothing. Subjectively, difficulty levels were significantly higher for ETI than for all other devices (P<.0001).

CONCLUSIONS

When compared with ETI, the use of SADs significantly shortened the time for AW control while wearing C-PPE. Second-generation SAD were superior to laryngeal mask AW unique. These finding suggest that SADs may be used in a mass toxicology event as a bridge, until definite AW control is achieved.

Utility of the Pentax-AWS in performing tracheal intubation while wearing chemical, biological, radiation and nuclear personal protective equipment: a randomised crossover trial using a manikin

INTRODUCTION

Following a chemical, biological, radiation and nuclear (CBRN) incident, prompt establishment of an advanced airway is required for patients with respiratory failure within the warm zone, while wearing personal protective equipment (PPE). Previous studies reported that intubation attempts were prolonged, and incidence of esophageal intubation was increased with conventional Macintosh laryngoscope (McL), while wearing CBRN-PPE. Pentax-AWS (AWS), a recently introduced portable video laryngoscope, was compared with the McL to test its utility for tracheal intubation while wearing CBRN-PPE.

METHODS

31 participants performed unsuited and suited intubations on an advanced life support simulator. The sequence of intubating devices and PPE wearing were randomised. Time to complete tracheal intubation (primary end point), time to see the vocal cords, overall success rate, percentage of glottic opening, dental compression and ease of intubation were measured.

RESULTS

Suited intubations required significantly longer time to complete intubation than unsuited intubations, in both McL and AWS (22.2 vs 26.4 s, 14.2 vs 18.2 s, respectively). However, suited AWS intubations required shorter time to complete tracheal intubation than unsuited McL intubations (18.2 vs 22.2 s). In secondary outcomes, moreover, suited intubations using the AWS compared favourably with unsuited intubations using the McL.

CONCLUSIONS

Although the CBRN-PPE adversely affected time required to complete tracheal intubation with the AWS, suited intubations using the AWS were even superior to unsuited intubations using the McL. The AWS should be a promising device to perform tracheal intubation while wearing the CBRN-PPE.

Emergency Airway Placement by EMS Providers: Comparison between the King LT Supralaryngeal Airway and Endotracheal Intubation

Introduction:

The ever-present risk of mass casualties and disaster situations may result in airway management situations that overwhelm local emergency medical services (EMS) resources. Endotracheal intubation requires significant user education/training and carries the risk of malposition. Furthermore, personal protective equipment (PPE) required in hazardous environments may decrease dexterity and hinder timely airway placement. Alternative airway devices may be beneficial in these situations.

Objective:

The objective of this study was to evaluate the time needed to place the King LT Supralaryngeal Airway compared to endotracheal intubation when performed by community EMS personnel with and without PPE.

Methods:

Following training, 47 EMS personnel were timed placing both endotracheal tubes and the King LT supralaryngeal airway in a simulator mannikin. The study participants then repeated this exercise wearing PPE.

Results:

The EMS personnel wearing PPE took significantly longer to place an endotracheal tube than they did without protective equipment (53.4 seconds and 39.5 seconds, p <0.002). The time to place the King LT was significantly faster than the placement of the endotracheal tube without protective equipment (18.4 seconds and 39.5 seconds, respectively, p<0.00003). There also were statistically significant differences between the time required to place the King LT and endotracheal tube in EMS personnel wearing protective equipment (19.7 seconds and 53.4 seconds, p <0.000007).

Conclusions:

The King LT Supralaryngeal Airway device may be advantageous in prehospital airway management situations involving multiple patients or hazardous environments. In this study, its insertion was faster than endotracheal intubation when performed by community EMS providers.

Insertion of six different supraglottic airway devices whilst wearing chemical, biological, radiation, nuclear-personal protective equipment: a manikin study

Six different supraglottic airway devices: Combitube™, laryngeal mask airway, intubating laryngeal mask airway (Fastrach™), i-gel™, Laryngeal Tube™ and Pro-Seal™ laryngeal mask airway were assessed by 58 paramedic students for speed and ease of insertion in a manikin, whilst wearing either chemical, biological, radiation, nuclear-personal protective equipment (CBRN-PPE) or a standard uniform. All devices took significantly longer to insert when wearing CBRN-PPE compared with standard uniform (p < 0.001). In standard uniform, insertion time was shorter than 45 s in 90% of attempts for all devices except the Combitube, for which 90% of attempts were completed by 53 s. Whilst wearing CBRN-PPE the i-gel was the fastest device to insert with a mean (SD (95% CI)) insertion time of 19 (8 (17-21))s, p < 0.001, with the Combitube the slowest with mean (65 (23 (59-71))s. Wearing of CBRN-PPE has a negative impact on supraglottic airway insertion time.

Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.

Influence of air-purifying respirators on the simulated first response emergency treatment of CBRN victims

AIM

Medical first responders and emergency room personnel potentially are threatened by exposure to primary or secondary intoxication by chemical, biological, radiological or nuclear (CBRN) substances. The impact of personal respiratory protection by air-purifying respirators on the performance of resuscitation requires evaluation. This will help to improve major incident planning and measures for protecting medical staff.

METHODS

We investigated the influence of two air-purifying respirator designs on the resuscitation of simulated CBRN victims. Fourteen UK paramedics followed a standardised resuscitation algorithm, either unprotected or wearing a bi-ocular and a panoramic visor respirator in a randomised crossover design. Treatment times and wearer comfort was determined and compared.

RESULTS

We did not find any difference in treatment times between the groups wearing respiratory protection and the controls (189+/-8.3s for the controls, 191+/-9.5s for the panoramic visor mask and 206+/-9.1s for the bi-ocular respirator [mean+/-S.E.M.]). Tracheal intubation appeared to be the most time consuming task. In a questionnaire, volunteers were of the opinion that orientation whilst wearing the respirator with the panoramic visor was better compared to the bi-ocular one (85% versus 15%). With respect to the fit, the majority (79%) rated the bi-ocular respirator as more comfortable.

CONCLUSIONS

Modern personal respiratory protection has only a negligible effect in the delay on the short term treatment during well defined simulated scenarios with a single CBRN casualty. Furthermore, air-purifying respirators with panoramic visors seem to allow a better orientation for medical first responders during simulated resuscitation.

Emergency department personal protective equipment requirements following out-of-hospital chemical biological or radiological events in Australasia

Recent events have led to a revision in ED equipment, preparedness and training for disasters. However, clinicians must still decide when, and what level of personal protection is required when a toxic threat exists. If possible, clear, simple and achievable protocols are required in such situations. Following an off‐site Australasian chemical biological or radiological incident, current evidence indicates that the initial receiving ED staff will be adequately protected from all known chemical biological and radiological inhalational threats by wearing a properly fitted P2 (N95) mask, or its equivalent. Protection from serious contact injury is offered by wearing double gloves, disposable fluid‐repellent coveralls or gown, eye protection, surgical mask, and ideally, a cap and shoe covers; in conjunction with universal precautions and procedures.

Nonconventional terror--the anesthesiologist's role in a nerve agent event

The structure and biologic action of nerve agents is similar to organophosphates, commonly used as insecticides. Acetylcholine accumulation and binding to the cholinergic receptor site stimulates the affected organs producing a predictable set of clinical symptoms. Treatment of the affected patients will include decontamination, respiratory and hemodynamic support, as well as specific antidotes. The multiple casualties that may be expected present additional logistical and organizational problems. The specific skills of anesthesiologists will make them invaluable members of the care team in such a chemical mass casualty event.

Role of the anaesthetist in developing and implementing readiness of hospital to mass casualty incidents

PURPOSE OF REVIEW

A mass casualty incident is usually short and resolves itself. To minimize the risks to patients during mass casualty incidents, planning is essential. We hereby provide our experience with a recent literature review of the steps to provide the hospital with an efficient plan to overcome mass casualty situations of a traumatic nature, with special implications for the anaesthetist's role.

RECENT FINDINGS

Preparation of the hospital starts with an accepting master plan and guidelines for creating local standing orders for this scenario. The hospital should work step by step in adjusting the master plan to its local requirements and infrastructure. During this work, one will find that it is not only technical or logistic but should address medical issues, with pertinent information from clinicians of different specialities. After authorization of the preparedness plan, it should be tested in limited scale drills, and then implemented in the hope that it will never need to be used. Periodic adjustments according to threats and new concepts and equipment should be made.

SUMMARY

As a result of recent events, a major effort is considered to improve the preparedness plan of the hospital for mass casualty incidents. However, common surveyors report their unease with the current ability to cope with disasters. The involvement of medical teams in the process is mandatory to lessen the effects of the first wave of casualties and to be able to cope with the second wave.

Securing the prehospital airway: a comparison of laryngeal mask insertion and endotracheal intubation by UK paramedics

OBJECTIVES

The recent introduction of a disposable laryngeal mask airway has provided paramedics with an alternative to endotracheal intubation. Time taken to secure the airway with each device was compared in patients undergoing elective surgery.

METHODS

Patients undergoing general anaesthesia were studied. Paramedics trained in laryngeal mask use and endotracheal intubation participated in the study. A Portex disposable laryngeal mask was inserted and removed, followed by a Portex endotracheal tube. Time taken from beginning of the procedure to ventilation of the patient was recorded.

RESULTS

Laryngeal mask insertion and endotracheal intubation was attempted on 52 patients. Median age was 63.5 years (range 39-83). Laryngeal mask insertion was successful in 88.5% (46 of 52) patients; endotracheal intubation was successful in 71.2% (37 of 52) patients (after no more than two attempts), p = 0.049. Intubation success was related to laryngoscopic view (87.5% grade 1, 56.3% grade 2, 0.0% grade 3. p<0.0001). When laryngeal mask/endotracheal tube insertion were both successful (n = 35 of 52), there was no significant difference in median time to secure the airway (laryngeal mask 47.0 seconds (range 24-126) compared with endotracheal tube 52.0 seconds (range 27-148) p = 0.22). Laryngeal mask insertion was successful in 80.0% (12 of 15) patients in whom endotracheal intubation had failed.

CONCLUSIONS

Even under optimal conditions, 30% of attempts at intubation by paramedics were unsuccessful. A disposable laryngeal mask has a higher success rate in securing the airway and overall, secures the airway more reliably than endotracheal intubation.

Laryngeal mask airway control versus endotracheal intubation by medical personnel wearing protective gear

The purpose of this study was to evaluate the rates of successful airway control using endotracheal tubes (ETs) or laryngeal mask airways (LMAs) and compare them between anesthetists and non-anesthetists wearing full antichemical protective gear. Anesthetists and non-anesthetists (n = 10 per group) twice attempted inserting ETs and LMAs on a mannequin model of airway management in a crossover, prospective manner. Times to successful insertion and failure rates were recorded. Non-anesthetists had a slightly higher failure rate inserting ETs compared with anesthetists (P = not significant). Respective mean times to successfully inserting ETs were 38 +/- 7.1 and 26.4 +/- 7.5 seconds (P < .05). Both groups inserted LMAs more rapidly than ETs (P < .05) and their failure rates in ET use were higher. In view of the relative rapidity by which LMAs were inserted as compared with ETs, by fully protected caregivers, the incorporation of LMA in algorithms dealing with emergency airway management in a nonconventional mass casualty scenario deserves further evaluation.

Application of a cuirass and institution of biphasic extra-thoracic ventilation by gear-protected physicians

OBJECTIVES

To evaluate the speed by which cuirass application, followed by biphasic extra-thoracic ventilation, can be instituted by full anti-chemical protective gear-wearing physicians.

MATERIALS AND METHODS

Ten physicians of variable subspecialties applied a cuirass on an adult volunteer and instituted biphasic extra-thoracic ventilation, using the RTX respirator (Medivent, London, UK). Endotracheal (ET) intubation and manual ventilation of a mannequin and its ventilation was comparatively assessed. Performances were conducted in a prospective, crossover, randomized manner. Times to successful applications as well as failure rates were recorded.

RESULTS

Cuirass application was performed more rapidly (102 +/- 9 s, 177 +/- 31 s, respectively, P <.01) and with a slightly lower failure rate than ET intubation.

CONCLUSIONS

Physicians wearing full anti-chemical protective gear applied the cuirass and instituted biphasic extra-thoracic ventilation faster than ET intubation and manual positive pressure ventilation. Extra-thoracic ventilation should be further evaluated as an option for emergent respiratory support during toxic mass casualty events.