Manikin-based Study Research Articles

The understandability and quality of telephone-guided bystander cardiopulmonary resuscitation in the Western Cape province of South Africa: A manikin-based study

BackgroundThe incidence of cardiovascular disease is on the increase in Africa and with it, an increase in the incidence of out-of-hospital cardiac arrest (OHCA). OHCA carries a high mortality, especially in low-resource settings. Interventions to treat OHCA, such as mass cardiopulmonary resuscitation (CPR) training campaigns are costly. One cost-effective and scalable intervention is telephone-guided bystander CPR (tCPR). Little data exists regarding the quality of tCPR. This study aimed to determine quality of tCPR in untrained members of the public. Participants were also asked to provide their views on the understandability of the tCPR instructions. MethodsThis study followed a prospective, simulation-based observational study design. Adult laypeople who have not had previous CPR training were recruited at public CPR training events and asked to perform CPR on a manikin. Quality was assessed in terms of hand placement, compression rate, compression depth, chest recoil, and chest exposure. tCPR instructions were provided by a trained medical provider, via loudspeaker. Participants were also asked to complete a short questionnaire afterwards, detailing the understandability of the tCPR instructions. Data were analysed descriptively and compared to recommended quality guidance. ResultsFifty participants were enrolled. Hand placement was accurate in 74 % (n = 37) of participants, while compression depth and chest recoil only had compliance in 20 % (n = 10) and 24 % (n = 12) of participants, respectively. The mean compression rate was within guidelines in just under half (48 %, n = 24) of all participants. Only 20 (40 %) participants exposed the manikin's chest. Only 46 % (n = 23) of participants felt that the overall descriptions offered during the tCPR guidance were understandable, while 80 % (n = 40) and 36 % (n = 18) felt that the instructions on hand placement and compression rate were understandable, respectively. Lastly, 94 % (n = 47) of participants agreed that they would be more likely to perform bystander CPR if they were provided with tCPR. ConclusionThe quality of CPR performed by laypersons is generally suboptimal and this may affect patient outcomes. There is an urgent need to develop more understandable tCPR algorithms that may encourage bystanders to start CPR and optimise its quality.

Comparison of the Effectiveness of Two Types of Commercial Endotracheal Tube Holders, with the Conventional Method in a Manikin Model.

Endotracheal intubation is employed to create a safe airway in patients requiring mechanical ventilation. The relatively high prevalence rate of unplanned displacement of the endotracheal tube (ETT) can be associated with serious complications. This study was conducted to evaluate the effectiveness of a newly designed tube holder in Iran (Irafit), the Thomas ETT holder and the traditional method using adhesive tape. The present manikin-based study was performed on the human mannequin. For this purpose, the mannequin was first subjected to oral intubation by a skilled emergency medicine specialist. Then, three methods of adhesive tape, Irafit-ETT holder, and Thomas-ETT holder were used. The mean of displacement in width of the mouth, length of the ETT, and depth as well as ETT removal was recorded. The results of the present study revealed that the displacement in depth was significantly less in the Irafit-ETT holder as compared with the other two groups following the application of a tug (P < 0.001). The displacement in the length of the ETT with and without the application of a tug was significantly less in the Irafit-ETT holder and Thomas-ETT holder groups as compared with the adhesive tape group (P < 0.001). According to the results of the present study, it can be stated that both ETT holder devices (Thomas vs. Irafit) were not distinct in terms of displacements in length and width; however, the Iranian model was more successful in minimizing the displacement in depth.

Borescope assisted intubation through Fekry intubating airway; a prospective observational study

Objectives: Airway management starts from the use of a nasal prong for oxygenation to successful endotracheal intubation for the ventilation. Intubation has been one of the most studied subject in anesthesiology. Various methods and gadgets have been advocated for its success. We aimed to evaluate the rate of successful intubations using the ordinary borescope and a stylet through Fekry Oral Intubating Airway (FOIA) in a manikin.&#x0D; Methodology: This manikin-based study enrolled 35 trainees, who performed endotracheal intubation guided by the borescope and used FOIA as a conduit. Every trainee was allowed two attempts. The primary outcome was to assess the success rate of intubation. Secondary outcomes included the precise time to intubate, number of attempts, and the need for external manipulations.&#x0D; Results: Our results revealed that 62.9% of the participants performed the intubation successfully (success rate) and 51.43% succeeded to intubate the manikin in the first attempt. External manipulation was needed by 71.4% of the participants in the form of cricoid pressure or laryngeal movement to visualize the glottic view. The time needed for a successful intubation ranged from 16 to 120 sec with a median of 50 sec and a mean of 69.37 ± 42.26 sec.&#x0D; Conclusion: A combination of Fekry Oral Intubating Airway, a borescope and an intubating stylet can be used for endotracheal intubation in remote areas, where advanced airway management aids are not available.. Future studies are warranted to optimize this technique.&#x0D; Trial registration: The ethical approval was obtained from the Research Ethics Committee of Cairo University (Code: MD-79-2019), and registration of the trial was performed on www.clinicaltrials.gov with a registration number (NCT05094453).&#x0D; Key words: Visually assisted intubation, Borescope, Fekry Oral Intubating Airway.&#x0D; Citation: Youssef MMI, Kamel OY, Asswa AR, Kassem SM, Abdelhalim RA, Inas Farouk I. Borescope assisted intubation through Fekry intubating airway; a prospective observational study. Anaesth. pain intensive care 2022;26(6):799−802.&#x0D; DOI: 10.35975/apic.v26i6.2050

Intubation during spinal motion restriction using the LuboTM cervical collar - a manikin simulation study.

IntroductionThe LuboTM collar is a cervical motion restriction device featuring a unique external jaw-thrust mechanism designed to provide non-invasive airway patency. In addition, tracheal intubation is facilitated by releasing an anterior chin strap; this allows better mouth opening than the previous generation of semi-rigid cervical collars. This study aimed to compare tracheal intubation using the LuboTM collar combined with manual in-line stabilization (MILS) to intubation with MILS alone. The primary outcome was the time to successful intubation. Secondary outcomes compared intubation success rate, Cormack-Lehane grade, ease of intubation and dental trauma.MethodsA randomized, cross-over, equivalence study was performed. Eighty full-time physician anaesthesia providers were recruited. Participants performed tracheal intubation using direct laryngoscopy on a manikin under two different scenarios: with the LuboTM collar and MILS applied, and with MILS and no cervical collar. The time to successful intubation was measured and compared using two-one-sided and paired t-tests.ResultsIntubation times fell well within the a priori equivalence limits of 10 seconds, with a mean difference (95% CI) of 0.52 seconds (-1.30 to 2.56). There was no significant difference in intubation time with the LuboTM collar (mean [SD] 19.2 [4.5] seconds) compared to the MILS alone group (19.7 [5.2] seconds). The overall success rate was 98.7% in the Lubo group and 100% in the MILS group. Adequate laryngoscopy views (Cormack-Lehane grades I to IIb) were equivalent between groups (Lubo 92.5% versus MILS alone 93.7%).ConclusionIn this manikin-based study, the time to intubation with the LuboTM collar and MILS applied was equivalent to time to intubation with MILS alone, with similar intubating conditions. Thus, the LuboTM collar and MILS may simplify airway management by reducing the number of steps required to perform intubation in patients requiring cervical motion restriction.

Comparison between C-MAC and King Vision video laryngoscope (channelled blade) for tracheal intubation in aerosol-prevention intubation box for COVID-19 patients: A manikin-based study.

Background and Aims:The risk of contracting infection while intubating a coronavirus disease 2019 (COVID-19)-positive patient can be reduced by the use of personal protective equipment (PPE), video laryngoscope (VL) and aerosol-preventing intubation box. We compared two VLs (C-MAC and King Vision laryngoscope [KVL]) for ease of intubation and time taken to intubate the manikin using an intubation box.Methods:This randomised study involved healthcare workers having experience in using both C-MAC and KVL. After explaining the study and five practice sessions, a total of 63 volunteers were included; 61 participants gave consent and were enroled. The participants were allowed to intubate initially with one VL as per random sequence. Each participant performed three tracheal intubations with each device (C-MAC VL and KVL) on a manikin using an aerosol-prevention box over the head end at the time of intubation.Results:Time taken, percentage of glottic opening (POGO) score and the number of attempts taken for successful intubation with C-MAC and KVL were comparable in any of the three attempts (P > 0.05). The participants reported more difficulty in using KVL compared to C-MAC, and insertion of laryngoscope blade into the mouth of manikin for intubation was easy in group C-MAC compared to KVL in all three intubations (P < 0.01).Conclusion:C-MAC and KVL take comparable time for successful intubation under COVID-19 simulation conditions. But C-MAC is more user-friendly.

Effects of Changes in Inspiratory Time on Inspiratory Flowrate and Airway Pressure during Cardiopulmonary Resuscitation: A Manikin-Based Study

Objectives Given that cardiopulmonary resuscitation (CPR) is an aerosol-generating procedure, it is necessary to use a mechanical ventilator and reduce the number of providers involved in resuscitation for in-hospital cardiac arrest in coronavirus disease (COVID-19) patients or suspected COVID-19 patients. However, no study assessed the effect of changes in inspiratory time on flowrate and airway pressure during CPR. We herein aimed to determine changes in these parameters during CPR and identify appropriate ventilator management for adults during CPR. Methods We measured changes in tidal volume (Vt), peak inspiratory flow rate (PIFR), peak airway pressure (Ppeak), mean airway pressure (Pmean) according to changes in inspiratory time (0.75 s, 1.0 s and 1.5 s) with or without CPR. Vt of 500 mL was supplied (flowrate: 10 times/min) using a mechanical ventilator. Chest compressions were maintained at constant compression depth (53 ± 2 mm) and speed (102 ± 2/min) using a mechanical chest compression device. Results Median levels of respiratory physiological parameters during CPR were significantly different according to the inspiratory time (0.75 s vs. 1.5 s): PIFR (80.8 [73.3 – 87.325] vs. 70.5 [67 – 72.4] L/min, P &amp;lt; 0.001), Ppeak (54 [48 – 59] vs. 47 [45 – 49] cmH 2 O, P &amp;lt; 0.001), and Pmean (3.9 [3.6 – 4.1] vs. 5.7 [5.6 – 5.8] cmH 2 O, P &amp;lt; 0.001). Conclusions Changes in PIFR, Ppeak, and Pmean were associated with inspiratory time. PIFR and Ppeak values tended to decrease with increase in inspiratory time, while Pmean showed a contrasting trend. Increased inspiratory time in low-compliance cardiac arrest patients will help in reducing lung injury during adult CPR.

Comparison between McGrath and Macintosh Laryngoscopes as an Educational Tool for Successful Intubation by Novice Airway Managers

Background: The Macintosh (MAC) laryngoscope has been the gold standard for teaching intubation till date. This manikin-based study was conducted to determine whether McGrath™ videolaryngoscope (VL) (McG) is comparable to MAC laryngoscope as an educational tool for novice airway managers. Material and Methods: A randomised cross-over manikin-based trial was conducted in a group of 44 final-year medical students. After training for intubation with both laryngoscopes, the students were randomised to Group MAC or Group McG to decide which laryngoscope would be used first. The total time for intubation, number of attempts for successful intubation, ease of visualisation and ease of intubation were assessed. Results: The median time for intubation was 40 s (interquartile range [IQR] 16.5–93.5) for the MAC group and 35 s (IQR 17.5–54.5 s) for McG group (P = 0.22). First attempt success was significantly more in the McG group. Ease of visualisation and ease of intubation were significantly better in the McG group (P ≤ 0.05). Conclusion: The McGrath™ VL appears to be superior to MAC laryngoscope as an educational tool for training novice airway managers in endotracheal intubation.

Proficiency of Laryngeal Mask Airway Insertion Skill in NRP Certified Providers.

Objective In 2015, Neonatal Resuscitation Program (NRP) recommended laryngeal mask airway (LMA) as an alternative to the endotracheal tube (ETT) in situations where the provider is “unable to intubate and unable to ventilate.” LMA insertion is being taught in the NRP routinely. However, endotracheal intubation is the primary method considered as the standard of care in neonatal resuscitation. LMA insertion is a relatively simple procedure with an average insertion time of < 10 seconds. Newer generation LMA can have the added advantage of reducing the risk of aerosol generation and improving the safety of the providers. Only a few recent studies have evaluated the LMA insertion skills of neonatal resuscitation providers. We wanted to study the proficiency of NRP providers in the technique of LMA insertion. We hypothesized that NRP providers would have LMA insertion skills equivalent to the standard of care (ETT insertion). Study Design A manikin-based study was done from July 2019 to December 2019. We enrolled 31 NRP providers with 1 or more years since the first certification and current valid NRP provider/instructor status. The participants were instructed to insert an ETT and LMA in the manikin. The procedures were video recorded. The time taken to insert and start ventilation with each device, including the number of attempts for successful insertion, was noted. A Likert scale questionnaire was filled by each participant indicating the level of confidence, perception of ease, and the ability to provide effective positive pressure ventilation (PPV) with each of the procedures. The paired t -test, chi-square test, and Kruskal–Wallis' test were used for the statistical analysis. Results Eight (25.8%) out of the 31 participants failed to insert any one of the devices. So, 23 providers were analyzed for the outcomes. We found that the mean duration taken to insert the ETT and LMA was not statistically different (32 vs. 36 seconds). LMA insertion had a higher failure rate compared with ETT. Providers did not perceive confidence to insert LMA when compared with ETT. They did not recognize LMA insertion as a more effortless procedure relative to endotracheal intubation. The providers felt that their ability to provide effective PPV using LMA was inferior to ETT. Conclusion The NRP certified providers in this study did not demonstrate proficiency in the insertion of LMA equivalent to the endotracheal intubation. Key Points LMA insertion skill was studied in NRP providers using a manikin.Providers had a higher frequency of failure in inserting LMA compared to ETT.Providers' perceived confidence and effectiveness of the LMA procedure were inferior to ETT.

Learning curve and performance in simulated difficult airway for the novel C-MAC® video-stylet and C-MAC® Macintosh video laryngoscope: A prospective randomized manikin trial.

Difficult airways can be managed with a range of devices, with video laryngoscopes (VLs) being the most common. The C-MAC® Video-Stylet (VS; Karl-Storz Germany), a hybrid between a flexible and a rigid intubation endoscope, has been recently introduced. The aim of this study is to investigate the performance of the VS compared to a VL (C-MAC Macintosh blade, Karl-Storz Germany) with regards to the learning curve for each device and its ability to manage a simulated difficult airway manikin. This is a single-center, prospective, randomized, crossover study involving twenty-one anesthesia residents performing intubations on a Bill 1™ (VBM, Germany) airway manikin model. After a standardized introduction, six randomized attempts with VL and VS were performed on the manikin. This was followed by intubation in a simulated difficult airway (cervical collar and inflated tongue) with both devices in a randomized fashion. The primary end-point of this study was the total time to intubation. All continuous variables were expressed as the median [interquartile range] and analyzed using the Mann-Whitney U test. A 2-way ANOVA with Bonferroni’s post hoc test was used to compare both devices at each trial. All reported p values are two sided. The median total time to intubation on a simulated difficult airway was faster with the VS compared to VL (17 [13.5–25] sec vs 23 [18.5–26.5] sec, respectively; 95% CI; P = 0.031). Additionally, on a normal airway manikin, the VS has a comparable learning curve to the VL. In this manikin-based study, the novel VS was comparable to the VL in terms of learning curve in a normal airway. In a simulated difficult airway, the total time to intubation, though likely not clinically relevant, was faster with the VS to the VL. However, given the above findings, this study justifies further human clinical trials with the VS to see if similar benefits–faster time to intubation and similar learning curve to VL–are replicated clinically.

Performance Comparison of N95 and P100 Filtering Facepiece Respirators with Presence of Artificial Leakage

National Institute for Occupational Safety and Health-approved P100 filtering facepiece respirators (FFRs) have a higher filter efficiency compared to the N95 filters. However, the former typically produce higher flow resistance (Rf). Consequently, when faceseal leakage is present, the proportion of leakage airflow for P100 FFRs may exceed that of N95s, resulting in a higher total inward leakage (TIL) of the P100. In this manikin-based study, the performance of two pairs of N95 and P100 FFRs (N95-A versus P100-A; N95-B versus P100-B) were compared under five sealing conditions (fully sealed and partially sealed with one, two, or three leaks of 0.8-mm, and one 2-mm leak). Sodium chloride particles (CMD ~45 nm) were used as the challenge aerosol. Respirators were tested under three constant flows (15, 50, and 85 L/min) and three cyclic flows (mean inspiratory flow = 15, 50, and 85 L/min). Both filter penetration (Pfilter) and TIL were determined. The Rf under constant flows was recorded. Based on Pfilter, TIL, and Rf, the quality factor (qf) was calculated to compare the overall performance of N95 and P100 FFRs. For a fully sealed condition, the Pfilter was much lower for the P100 FFRs than for the N95 FFRs. When small leaks were inserted (0.8-mm and 2 × 0.8-mm), the TIL was higher for the P100 FFRs than for the N95 FFRs under the lowest tested flow (15 L/min), while for greater leaks (3 × 0.8-mm and 2-mm), the TIL of the P100 FFRs was always higher regardless of the flow. The Rf of P100 FFRs was measured twice as high as the N95. The qf values were also found higher for the N95 FFRs than for the P100 FFRs regardless of leak size and breathing flow. With the presence of artificial leakage, a P100 FFR with high-flow-resistance may not be as protective as a low-flow-resistance N95 FFR. This finding suggests that future efforts should be directed to reducing the breathing resistance when designing P100 FFRs.

Comparison of Different Intubation Methods in Difficult Airways during Simulated Cardiopulmonary Resuscitation with Continuous Chest Compression: A Randomized Cross-Over Manikin Trial

Introduction Airway management is one of key elements of resuscitation. Endotracheal intubation is still considered the gold standard for airway management during resuscitation. Aim The aim of the study was to compare success rates and intubation time of different endotracheal intubation methods during emergency intubation with difficult airways in the conditions of cardiopulmonary resuscitation in a standardized manikin model. Methods The study was designed as a prospective, randomized, cross-over simulation study. It involved 46 paramedics with at least 5 years of experience in Emergency Medical Service. The participants performed endotracheal intubation under difficult airway conditions during continuous chest compression, implemented with the LUCAS3 chest compression system. Three methods of tracheal intubation were applied: (1) standard Macintosh laryngoscope without a bougie stylet; (2) standard laryngoscope and a standard bougie stylet; (3) standard laryngoscope and a new bougie stylet. Results The overall intubation success rate was 100% in the standard bougie and new bougie groups and lower (86.9%) when no bougie stylet was used (P=0.028). The intubation success rate with the 1st attempt equalled 91.3% for the new bougie group, 73.9% for standard bougie, and only 23.9% in the no-bougie group. The median intubation time was shortest in the new bougie group, where it amounted to 29 s (interquartile range [IQR]: 25–38); the time equalled 38s (IQR:31–44.5) in the standard bougie group and 47.5s (IQR:36–58) in the no-bougie group. The ease of use was lowest in the no-bougie group (85, IQR:63–88), average in the standard bougie group (44, IQR:30–51), and highest in the new bougie stylet group (32, IQR:19–41). Conclusion In this manikin-based study, paramedics were able to perform endotracheal intubation with higher efficacy and in a shorter time using the new bougie stylet as compared with the standard bougie stylet.

Manikin-based size-resolved penetrations of CE-marked filtering facepiece respirators

ABSTRACTThe purpose of this manikin-based study was to determine the percentage penetrations of nine CE-marked filtering facepiece respirator models (two samples from each) from filtering classes FFP1, FFP2, and FFP3 and to demonstrate by an independent measurement method the disadvantages and shortcomings of the currently valid European Norm (EN 149:2001) for filtering facepieces. All of the filtering facepieces were evaluated size-selectively in an experimental chamber using charge-neutralized monodisperse ammonium sulfate in 9 sizes ranging from 20–400 nm of count median diameter (CMD) under flowrate of 95 L/min. The results were then compared to the previous study concerning penetrations of 47-mm diameter filters cut from the filtering material of identical filtering facepieces. Although these two experimental methods for measuring penetrations of filtering materials from filtering facepieces are in good agreement (R2 = 0.91), the results show within-respirator variations in all three filtering classes (5.5–19.3% for all FFRs in FFP1, 2.8–8.5% in FFP2, and 0.1–2.8% in FFP3). The most penetrating particle size (MPPS) in this study was found to be in the range of 25–65 nm (CMD), which is in agreement with the range of 30–60 nm found in the previous study. Moreover, 7 out of 9 FFR models reached higher penetrations from manikin-based respirator measurements than during measurements of filters from the respective respirators. Furthermore, penetration levels increased up to ∼50% when the respirator was not sealed around the face of the manikin, indicating that the real protection level provided by these filtering facepieces may be even lower if the respirator does not fit perfectly. Considering that poor filtration efficiency and poor fit may increase under real work conditions, the particle penetration is even higher than was found in this study. Therefore, the CE-marked respirators examined in this study may not be efficient in providing the expected level of protection for workers exposed to nanoparticles.

The novel video‐assisted intubating laryngeal mask Totaltrack compared to the intubating laryngeal mask Fastrach – a controlled randomized manikin study

The novel Totaltrack combines a supraglottic airway device with video laryngoscopic tracheal intubation. The intubation laryngeal mask Fastrach is an established device without visual control of intubation. We hypothesized that supraglottic ventilation success with Totaltrack would be similar to Fastrach, but intubation would be performed faster due to visual control of the procedure. Fifty-five anaesthesiologists were randomized into one of two study arms: Fastrach Totaltrack. After a standardized introduction, six consecutive attempts of supraglottic ventilation and intubation attempts with each of one of the devices were performed on an airway manikin. The combined primary outcome was: time to supraglottic ventilation and time to ventilation after intubation. Additionally, success rate and learning curves were evaluated. Supraglottic time to ventilation was shorter when using the Fastrach compared to the Totaltrack (median: 7.8s [confidence interval [CI]: 7.0-8.6s] vs. 11s [CI: 7.8-14.2s], P<0.001). Intubation was faster using the Fastrach compared to Totaltrack (median: 12.5s, [CI: 10.1-14.9s] vs. 23.3s [CI: 21.5-25.1s], P<0.001). Success rate for supraglottic ventilation was comparable between Fastrach and Totaltrack (86-96%). Successful intubation via the device was 100% in Fastrach and ranged from 61% to 93% in Totaltrack, with a higher probability of successful intubation after four applications. In this manikin-based study the novel Totaltrack did not prove superior to Fastrach despite a similar design. Video laryngoscopic control of supraglottic ventilation and endotracheal intubation was prolonged using the Totaltrack. Clinical trials are mandatory to evaluate the role of the Totaltrack in airway management.

Performance of N95 FFRs Against Combustion and NaCl Aerosols in Dry and Moderately Humid Air: Manikin-based Study.

The first objective of this study was to evaluate the penetration of particles generated from combustion of plastic through National Institute for Occupational Safety and Health (NIOSH)-certified N95 filtering facepiece respirators (FFRs) using a manikin-based protocol and compare the data to the penetration of NaCl particles. The second objective was to investigate the effect of relative humidity (RH) on the filtration performance of N95 FFRs. Two NIOSH-certified N95 FFRs (A and B) were fully sealed on a manikin headform and challenged with particles generated by combustion of plastic and NaCl particles. The tests were performed using two cyclic flows [with mean inspiratory flow (MIF) rates = 30 and 85 l min(-1), representing human breathing under low and moderate workload conditions] and two RH levels (≈20 and ≈80%, representing dry and moderately humid air). The total and size-specific particle concentrations inside (C in) and outside (C out) of the respirators were measured with a condensation particle counter and an aerosol size spectrometer. The penetration values (C in/C out) were calculated after each test. The challenge aerosol, RH, MIF rate, and respirator type had significant (P < 0.05) effects on the performance of the manikin-sealed FFR. Its efficiency significantly decreased when the FFR was tested with plastic combustion particles compared to NaCl aerosols. For example, at RH ≈80% and MIF = 85 l min(-1), as much as 7.03 and 8.61% of combustion particles penetrated N95 respirators A and B, respectively. The plastic combustion particles and gaseous compounds generated by combustion likely degraded the electric charges on fibers, which increased the particle penetration. Increasing breathing flow rate or humidity increased the penetration (reduced the respirator efficiency) for all tested aerosols. The effect of particle size on the penetration varied depending on the challenge aerosol and respirator type. It was observed that the peak of the size distribution of combustion particles almost coincided with their most penetrating particle size, which was not the case for NaCl particles. This finding was utilized for the data interpretation. N95 FFRs have lower filter efficiency when challenged with contaminant particles generated by combustion, particularly when used under high humidity conditions compared to NaCl particles.

Performance of an improperly sized and stretched-out loose-fitting powered air-purifying respirator: Manikin-based study

ABSTRACTThe objective of this study was to investigate the protection level offered by a Powered Air-Purifying Respirator (PAPR) equipped with an improperly sized or stretched-out loose-fitting facepiece using constant and cyclic flow conditions. Improperly sized PAPR facepieces of two models as well as a stretched-out facepiece were tested. These facepieces were examined in two versions: with and without exhaust holes. Loose-fitting facepieces (size “large”) were donned on a small manikin headform and challenged with sodium chloride (NaCl) aerosol particles in an exposure chamber. Four cyclic flows with mean inspiratory flows (MIFs) of 30, 55, 85, and 135 L/min were applied using an electromechanical Breathing Recording and Simulation System (BRSS). The manikin Fit Factor (mFF) was determined as the ratio of aerosol concentrations outside (Cout) to inside (Cin) of the facepiece, measured with a P-Trak condensation particle counter (CPC). Results showed that the mFF decreased exponentially with increasing MIF. The mFF values of the stretched-out facepiece were significantly lower than those obtained for the undamaged ones. Facepiece type and MIF were found to significantly affect the performance of the loose-fitting PAPR. The effect of the exhaust holes was less pronounced and depended on the facepiece type. It was concluded that an improperly sized facepiece might potentially offer relatively low protection (mFF < 250) at high to strenuous workloads. The testing was also performed at a constant inhalation flow to explore the mechanism of the particle-facepiece interaction. Results obtained with cyclic flow pattern were consistent with the data generated when testing the loose-fitting PAPR under constant flow conditions. The time-weighted average values of mFF calculated from the measurements conducted under the constant flow regime were capable of predicting the protection under cyclic flow regime. The findings suggest that program administrators need to equip employees with properly sized facepieces and remove stretched-out ones from workplace. Manufacturers should emphasize the importance of proper sizing with their user instructions.

Rescuer factors predict high-quality CPR—a manikin-based study of health care providers

BackgroundIn the provision of high-quality cardiopulmonary resuscitation (CPR) by health care providers, factors associated with high-quality CPR should be explored. MethodsThis is a post hoc analysis using data from a manikin-based survey of CPR quality among volunteer emergency medical technicians (EMTs) from 2 county fire departments in northern Taiwan. ResultsAmong the 95 enrolled EMTs, 36 (37.9%) performed high-quality CPR on a manikin. The baseline characteristics that differed significantly between groups were board-certified EMT levels (P = .010), body mass index (BMI, P = .029), average exercise frequency (P = .001), and average exercise duration (P = .005). Average total exercise time per week, which uses frequency times exercise duration, was independently associated with high-quality CPR performance after adjusting for variables via logistic regression analysis (odds ratio, 1.004; P = .044). An index was developed (BMI × ExeTime) based on the product of BMI and average total exercise time per week. A comparison of the area under curve for the different indices showed that BMI × ExeTime was a significant predictor of high-quality CPR, with an area under curve of 0.718 (95% confidence interval, 0.613-0.824; P < .001; Fig. 2) and a cutoff value of 4136.7 kg·min/m2 (sensitivity, 0.722; specificity, 0.678). ConclusionsThis study identified factors associated with the performance by health care providers of high-quality CPR, including BMI and exercise habits. To optimize CPR quality, a program of exercise frequency and duration adjusted according to individual's BMI should be considered in such populations.

Comparison of three supraglottic airway devices for airway rescue in the prone position: A manikin-based study.

Background:Accidental extubation during surgery in prone position can be life-threatening. Supraglottic airway devices (SAD) have been used successfully in such situations to rescue the airway. However, which SAD would be most appropriate in this setting has not been described in the literature.Aims:The aim of our study was to determine the most appropriate SAD for securing airway in a prone position during accidental extubation.Materials and Methods:In the study, Airway Trainer (Laerdal) manikin was used for studying insertion of three SADs; I-gel, Laryngeal Mask Airway ProSeal™ (PLMA) and LMA Classic™ (CLMA) in the prone position. Forty anesthesia resident doctors participated in this study. The time taken for insertion; ease of insertion and ventilation; bronchoscopic view; and insertion score were compared among the three groups.Results:The time taken for I-gel insertion was significantly lesser (12.89 ± 3.94 seconds) as compared to CLMA (17.07 ± 3.5 seconds) and PLMA (25 + 4.78 seconds). Least resistance was encountered in the insertion of I-gel, while maximum resistance was experienced in PLMA group (22.5% vs. 90%). The maneuver required for optimal positioning was observed in 27.5% of PLMA insertion, 2.5% in CLMA while no maneuver was required in any of the I-gel insertion. Ease of ventilation was comparable in all three SADs. The bronchoscopic view and insertion score were significantly higher with I-gel as compared to CLMA and PLMA.Conclusion:All three SADs were successful as rescue devices during accidental extubation in the prone position. However, the ease of insertion was maximum with I-gel, followed by CLMA and PLMA.

Bag-mask ventilation and direct laryngoscopy versus intubating laryngeal mask airway

The percentage of hands-on time during cardiopulmonary resuscitation is a major determinant of patient outcome. We hypothesized that airway management with the intubating laryngeal mask airway (ILMA) would give greater hands-on time than with bag-mask ventilation (BMV), followed by direct laryngoscopy (DL), particularly in difficult-to-manage airways. Thirty paramedics and 40 medical students performed four standardized, 6-min cardiopulmonary resuscitation scenarios with the SimMan3G in a random sequence. These were normal and difficult-to-manage airways using either BMV+DL or ILMA. The time to the first successful ventilation was significantly longer with the ILMA (P<0.001). Hands-on time was lower for the ILMA after 2 min (67±8 vs. 81±8 s for BMV+DL, P<0.001), but was then significantly greater from the third minute onward (115±11 vs. 104±9 s for BMV+DL, P<0.001). The success rate of the first intubation attempt was higher and the time to ET placement was shorter with the ILMA, especially in the difficult-to-manage airway (P<0.001). In this manikin-based study, hands-on time was greater with the ILMA than with BMV+DL. The ILMA was particularly useful in increasing hands-on times in the difficult-to-manage airway.

Does the site of anterior tracheal puncture affect the success rate of retrograde intubation? A prospective, manikin-based study.

Background. Retrograde intubation is useful for obtaining endotracheal access when direct laryngoscopy proves difficult. The technique is a practical option in the “cannot intubate / can ventilate” scenario. However, it is equally useful as an elective technique in awake patients with anticipated difficult airways. Many practitioners report difficulty successfully advancing the endotracheal tube due to anatomical obstructions and the acute angle of the anterograde guide. The purpose of this study was to test whether a more caudal tracheal puncture would increase the success rate. Methods. Twenty-four anesthesiology residents were randomly assigned to either a cricothyroid or a cricotracheal puncture group. Each was instructed how to perform the technique and then attempted it on a manikin at their assigned site. Data collection included whether the trachea was intubated, the number of attempts required, and the total time. Results. Both groups displayed a high degree of success. While the group assigned to the cricotracheal site required significantly more time to perform the procedure, they accomplished it in fewer attempts than the cricothyroid group. Conclusion. Retrograde intubation performed via a cricotracheal puncture site, while more time consuming, resulted in fewer attempts to advance the endotracheal tube and may reduce in vivo laryngeal trauma.

Comparison of six different intubation aids for use while wearing CBRN-PPE: A manikin study

Introduction Respiratory failure following chemical exposure can be fatal and although supraglottic airway devices have been evaluated for use in the management of CBRN casualties’ intubation remains the gold standard airway. Methods This is a randomised cross-over study involving 66 paramedic students utilising the following intubating aids bougie, stylet, McCoy laryngoscope, Airtraq™, intubating laryngeal mask (ILMA) and standard intubation. Each participant performed intubation with each device while wearing standard uniform and CBRN-PPE. Results While wearing standard uniform all intubation aids, except the Airtraq™, resulted in at least a 90% successful intubation rate by 60 s. The use of CBRN-PPE led to significantly longer intubation times (ranging from 14.3 to 20.7 s) depending on intubation aid used ( p < 0.001) with a 90% successful intubation rate not being achieved by all devices even by 150 s. While wearing CBRN-PPE standard intubation and intubation with a stylet were the fastest whereas the ILMA was deemed the easiest to use with the highest success rate. A marked deterioration in the number of intubation attempts completed within 30 s was also noted with standard intubation deteriorating by 82%, stylet deteriorating by 96% and the McCoy by 100%. The deterioration in intubation success at 60 s was less marked. Conclusion In this manikin-based study all intubation aids evaluated while wearing CBRN-PPE were adversely affected by the loss of dexterity associated with wearing Butyl gloves. Standard intubation and intubation utilising a stylet resulted in the fastest intubation times; whereas the ILMA offers the highest intubation success rate and was deemed to be the easiest intubating aid to use. An important consideration with regards future research is the impact of a learning curve with regards to different intubation aids and whether preassembling all the intubation aids prior to the intubation attempt may improve intubation speed. The impact of intubator familiarity with regards to individual intubation aids is also an important consideration but established intubation aids like the Bougie are more difficult to use when dexterity is reduced due to CBRN-PPE.