Aerosol Delivery Through Adult High Flow Nasal Cannula With Heliox and Oxygen.

BACKGROUND: Heliox (helium-oxygen mixture) has been shown to reduce turbulence and improve aerosol delivery in a range of clinical settings. We questioned whether heliox as compared with oxygen via high-flow nasal cannula (HFNC) would affect aerosol delivery. We hypothesized that heliox would have a significant effect on aerosol delivery as compared with oxygen with both quiet and distressed breathing patterns. METHODS: A vibrating mesh nebulizer was placed at the inlet of a humidifier via HFNC with small adult cannula distal to the heated-wire circuit with prongs placed into simulated nares with a T-shaped trap and absolute filter connected to a breath simulator set to adult quiet and distressed breathing parameters. Albuterol sulfate (0.083% 2.5 mg/3 mL) was aerosolized with heliox (80:20) and oxygen (100%) at 10, 30, and 50 L/min. Drug eluted from the filter was assayed with UV spectrophotometry (276 nm). Descriptive statistics, Kruskal-Wallis test, and Mann-Whitney U test were used for data analysis. P < .05 was considered statistically significant. RESULTS: Increasing flows with heliox and oxygen significantly decreased percentage inhaled dose (inhaled dose) of aerosol with a quiet breathing pattern (P = .02 and P = .030, respectively). In contrast, with a distressed breathing pattern, inhaled dose at 10 L/min was lower than at 30 and 50 L/min (P = .009 and P = .01, respectively) with both oxygen and heliox (P = .009 and P = .009, respectively). Despite a trend to higher aerosol deposition with heliox versus oxygen, the differences were not significant. CONCLUSIONS: With a distressed breathing pattern, aerosol delivery was greater at 30 and 50 L/min than with a quiet breathing pattern. Trends toward higher inhaled dose with heliox during HFNC were not significant.

Quantifying Aerosol Delivery in Simulated Spontaneously Breathing Patients With Tracheostomy Using Different Humidification Systems With or Without Exhaled Humidity.

BACKGROUND: Aerosol and humidification therapy are used in long-term airway management of critically ill patients with a tracheostomy. The purpose of this study was to determine delivery efficiency of jet and mesh nebulizers combined with different humidification systems in a model of a spontaneously breathing tracheotomized adult with or without exhaled heated humidity. METHODS: An in vitro model was constructed to simulate a spontaneously breathing adult (tidal volume, 400 mL; breathing frequency, 20 breaths/min; inspiratory-expiratory ratio, 1:2) with a tracheostomy using a teaching manikin attached to a test lung through a collecting filter (Vital Signs Respirgard II). Exhaled heat and humidity were simulated using a cascade humidifier set to deliver 37°C and >95% relative humidity. Albuterol sulfate (2.5 mg/3 mL) was administered with a jet nebulizer (AirLife Misty Max) operated at 10 L/min and a mesh nebulizer (Aeroneb Solo) using a heated pass-over humidifier, unheated large volume humidifier both at 40 L/min output and heat-and-moisture exchanger. Inhaled drug eluted from the filter was analyzed via spectrophotometry (276 nm). RESULTS: Delivery efficiency of the jet nebulizer was less than that of the mesh nebulizer under all conditions (P < .05). Aerosol delivery with each nebulizer was greatest on room air and lowest when heated humidifiers with higher flows were used. Exhaled humidity decreased drug delivery up to 44%. CONCLUSIONS: The jet nebulizer was less efficient than the mesh nebulizer in all conditions tested in this study. Aerosol deposition with each nebulizer was lowest with the heated humidifier with high flow. Exhaled humidity reduced inhaled dose of drug compared with a standard model with nonheated/nonhumidified exhalation. Further clinical research is warranted to understand the impact of exhaled humidity on aerosol drug delivery in spontaneously breathing patients with tracheostomy using different types of humidifiers.

Pressurized Metered-Dose Inhalers Versus Nebulizers in the Treatment of Mechanically Ventilated Subjects With Artificial Airways: An In Vitro Study.

BACKGROUND: The primary focus of previous aerosol research during mechanical ventilation was the endotracheal tube (ETT). Consequently, there are limited data in the literature on the delivery of inhaled medications administered with different aerosol devices in mechanically ventilated patients with a tracheostomy tube (TT). The purpose of this study was to quantify and compare the efficiency of aerosol devices in a lung model of an intubated and mechanically ventilated adult with a TT. METHODS: An in vitro lung model was constructed to simulate a ventilator-dependent adult with a Portex TT and a Mallinckrodt ETT (8-mm inner diameter). Aerosol was collected distal to the bronchi of an adult mannikin on a filter attached to a passive test lung. A ventilator delivered adult breathing parameters (tidal volume 450 mL, breathing frequency 20 breaths/min, peak expiratory flow 40 L/min, and inspiratory-expiratory ratio 1:3) to the airway. A jet nebulizer and pressurized metered-dose inhaler (pMDI) were placed in the inspiratory limb of the circuit 15 cm from the Y-adapter. The jet nebulizer was operated at 8 L/min to deliver albuterol sulfate (2.5 mg/3 mL), whereas an albuterol pMDI was actuated 4 times with a spacer. Drug was eluted from the filter and analyzed by spectrophotometry. RESULTS: Drug delivered via a TT was marginally greater compared with an ETT using the jet nebulizer and pMDI (P = .10 and .046, respectively). Although delivery efficiency with the pMDI was 3-fold greater than with the jet nebulizer with both a TT and an ETT (P = .001 and .002, respectively), the jet nebulizer delivered greater drug mass compared with the pMDI with either a TT (P = .01) or an ETT (P = .005). CONCLUSIONS: Aerosol drug delivery via a TT was greater than with an ETT, whereas the delivery efficiency of a pMDI via either airway was greater than that of a jet nebulizer.

Comparison of Aerosol Delivery by Face Mask and Tracheostomy Collar.

BACKGROUND: The purpose of this study was to compare the performance of a tracheostomy collar, Wright mask, and aerosol mask attached to a jet nebulizer in facilitating aerosolized medication delivery to the lungs. We also compared albuterol delivery with open versus closed fenestration and determined the effect of inspiratory-expiratory ratio (I:E) on aerosol delivery. METHODS: Albuterol (2.5 mg/3 mL) was administered to an in vitro model consisting of an adult teaching mannequin extrathoracic and upper airway with stoma intubated with an 8-mm fenestrated tracheostomy tube. The cuff was deflated. A collecting filter at the level of the bronchi was connected to a breathing simulator at a tidal volume of 400 mL, breathing frequency of 20 breaths/min, and I:E of 2:1 and 1:2. A jet nebulizer was operated with O2 at 8 L/min. Each interface was tested in triplicate. The flow was discontinued at the end of nebulization. For each test, the nebulizer was attached to a tracheostomy collar with the fenestration open or closed, a Wright mask, or an aerosol mask. Drug was analyzed by spectrophotometry (276 nm). A paired t test and analysis of variance were performed (P < .05). RESULTS: The mean ± SD percent albuterol dose delivered distal to the bronchi was greater with the tracheostomy collar with a closed fenestration (9.4 ± 1.5%) compared with an open fenestration (7.0 ± 0.8%). The doses delivered with the Wright mask (4.1 ± 0.6%) and aerosol mask (3.5 ± 0.04%) were both less than with the tracheostomy collar under either condition (P < .05). Increasing the I:E from 1:2 to 2:1 increased aerosol delivery by 2.5-4%, with significance for the tracheostomy collar with an open fenestration (11.6 ± 1.4%), Wright mask (7.2 ± 0.6%), and aerosol mask (6.1 ± 0.5%). CONCLUSIONS: In an adult tracheostomy model, the tracheostomy collar delivered more aerosol to the bronchi than the Wright or aerosol mask. An I:E of 2:1 caused greater aerosol deposition compared with an I:E of 1:2. During aerosol administration via a tracheostomy collar, closing the fenestration improved aerosol delivery.

Effect of Aerosol Devices and Administration Techniques on Drug Delivery in a Simulated Spontaneously Breathing Pediatric Tracheostomy Model.

BACKGROUND: This study was conducted to compare the efficiency of jet nebulizers, vibrating mesh nebulizers, and pressurized metered-dose inhalers (pMDI) during assisted and unassisted administration techniques using a simulated spontaneously breathing pediatric model with a tracheostomy tube (TT). METHODS: An in vitro breathing model consisting of an uncuffed TT (4.5-mm inner diameter) was attached to a collecting filter (Respirgard) connected to a dual-chamber test lung and a ventilator (Hamilton Medical) to simulate breathing parameters of a 2-y-old child (breathing frequency, 25 breaths/min; tidal volume, 150 mL; inspiratory time, 0.8 s; peak inspiratory flow, 20 L/min). Albuterol sulfate was administered using a jet nebulizer (MicroMist, 2.5 mg/3 mL), vibrating mesh nebulizer (Aeroneb Solo, 2.5 mg/3 mL), and pMDI (ProAir HFA, 432 µg). Each device was tested 5 times with an unassisted technique (direct administration of aerosols with simulated spontaneous breathing) and with an assisted technique (using a manual resuscitation bag in conjunction with an aerosol device and synchronized with inspiration). Drug collected on the filter was analyzed by spectrophotometry. RESULTS: With the unassisted technique, the pMDI had the highest inhaled mass percent (IM%, 47.15 ± 7.82%), followed by the vibrating mesh nebulizer (19.77 ± 2.99%) and the jet nebulizer (5.88 ± 0.77%, P = .002). IM was greater with the vibrating mesh nebulizer (0.49 ± .07 mg) than with the pMDI (0.20 ± 0.03 mg) and the jet nebulizer (0.15 ± 0.01 mg, P = .007). The trend of lower deposition with the assisted versus unassisted technique was not significant for the jet nebulizer (P = .46), vibrating mesh nebulizer (P = .19), and pMDI (P = .64). CONCLUSIONS: In this in vitro pediatric breathing model with a TT, the pMDI delivered the highest IM%, whereas the vibrating mesh nebulizer delivered the highest IM. The jet nebulizer was the least efficient device. Delivery efficiency was similar with unassisted and assisted administration techniques.

Comparison of HFNC, bubble CPAP and SiPAP on aerosol delivery in neonates: An in-vitro study.

UNLABELLED: Aerosol drug delivery via high flow nasal cannula (HFNC), bubble continuous positive airway pressure (CPAP), and synchronized inspiratory positive airway pressure (SiPAP) has not been quantified in spontaneously breathing premature infants. OBJECTIVES: The purpose of this study was to compare aerosol delivery via HFNC, bubble CPAP, and SiPAP in a model of a simulated spontaneously breathing preterm infant. WORKING HYPOTHESIS: The types of CPAP systems and nebulizer positions used during aerosol therapy will impact aerosol deposition in simulated spontaneously breathing infants. STUDY DESIGN: Quantitative, comparative, in-vitro study. METHODOLOGY: A breath simulator was set to preterm infant settings (VT : 9 ml, RR: 50 bpm and Ti: 0.5 sec) and connected to the trachea of an anatomical upper airway model of a preterm infant via collecting filter distal to the trachea. The HFNC (Optiflow; Fisher & Paykel), Bubble CPAP (Fisher & Paykel), and SiPAP (Carefusion) were attached to the nares of the model via each device's proprietary nasal cannula and set to deliver a baseline of 5 cm H2 O pressure. Albuterol sulfate (2.5 mg/0.5 ml) was aerosolized with a mesh nebulizer (Aeroneb Solo) positioned(1) proximal to the patient and(2) prior to the humidifier (n = 5). The drug was eluted from the filter with 0.1 N HCl and analyzed via spectrophotometry (276 nm). Data were analyzed using descriptive statistics, t-tests, and one-way analysis of variance (ANOVA), with P < 0.05 significant. RESULTS: At position 1, the trend of lower deposition (mean ± SD%) across devices was not significant (0.90 ± 0.26, 0.70 ± 0.16 and 0.59 ± 0.19, respectively; P = 0.098); however, in position 2, drug delivery with SiPAP (0.79 ± 0.11) was lower compared to both HFNC (1.30 ± 0.17; P = 0.003) and bubble CPAP (1.24 ± 0.24; p = 0.008). Placement of the nebulizer prior to the humidifier increased deposition with all devices (P < 0.05). CONCLUSIONS: Aerosol can be delivered via all three devices used in this study. Device selection and nebulizer position impacted aerosol delivery in this simulated model of a spontaneously breathing preterm infant.

In Vitro Comparison of Aerosol Delivery Using Different Face Masks and Flow Rates With a High-Flow Humidity System.

BACKGROUND: Aerosol drug delivery to infants and small children is influenced by many factors, such as types of interface, gas flows, and the designs of face masks. The purpose of this in vitro study was to evaluate aerosol delivery during administration of gas flows across the range used clinically with high-flow humidity systems using 2 aerosol masks. METHODS: A spontaneous lung model was used to simulate an infant/young toddler up to 2 y of age and pediatric breathing patterns. Nebulized salbutamol by a vibrating mesh nebulizer positioned at the inlet of a high-flow humidification system at gas flows of 3, 6, and 12 L/min was delivered via pediatric face masks to a pediatric face mannequin attached to a filter. Aerosol particle size distribution exiting the vibrating mesh nebulizer and at the mask position distal to the heated humidifier with 3 flows was measured with a cascade impactor. Eluted drug from the filters and the impactor was analyzed with a spectrophotometer (n = 3). Statistical analysis was performed by analysis of variance with a significant level of P < .05. RESULTS: The inhaled mass was between 2.8% and 8.1% among all settings and was significantly lower at 12 L/min (P = .004) in the pediatric model. Drug delivery with pediatric breathing was greater than with infant breathing (P = .004). The particle size distribution of aerosol emitted from the nebulizer was larger than the heated humidified aerosol exiting the tubing (P = .002), with no difference between the 3 flows (P = .10). CONCLUSIONS: The flows of gas entering the mask and breathing patterns influence aerosol delivery, independent of the face mask used. Aerosol delivery through a high-flow humidification system via mask could be effective with both infant and pediatric breathing patterns.

An attending physician float shift for the improvement of physician productivity in a crowded emergency department.

BACKGROUND: Patients backlogged in the emergency department (ED) waiting for an inpatient bed (boarders) continue to require the attention of ED physicians, exacerbating crowding in the ED. To address this problem, we added a "float shift" to our winter schedule solely to care for boarders. We sought to quantify the effect of this float shift, hypothesizing greater physician productivity. METHODS: We performed a retrospective observational study in our community hospital ED, measuring the number of new patients seen in each 10-hour shift in the presence or absence of a float shift physician. We calculated the number of new patients seen per shift for each of the 7 daily shifts, during February (float shift scheduled) and May (float shift unscheduled) of 2008. We then compared the mean number of patients seen per shift in February with May. RESULTS: Total monthly patient volume was 6 656 for February and 6 775 for May, with the mean daily census being 230 and 219 patients, respectively. The number of new patients seen during each shift was greater in February than in May, with a mean increase of 1.1 patients per shift (with the float shift). Surveying participants about intervention effectiveness showed 92% of residents, but only 65% of attending physicians, in favor of maintaining the float shift. CONCLUSION: The presence of a "float shift" physician caring only for boarding patients allows other physicians to maintain and even increase their productivity in our ED, despite the presence of longer throughput times and increased time on diversion.

An in vitro evaluation of aerosol delivery through tracheostomy and endotracheal tubes using different interfaces.

BACKGROUND: Previous research reporting factors influencing aerosol delivery in intubated patients has been largely focused on the endotracheal tube (ETT) during mechanical ventilation, with little comparative analysis of effect of types of artificial airways and their interfaces on aerosol delivery during spontaneous breathing. The purpose of this study was to compare aerosol delivery via tracheostomy tube (TT) and ETT, using interfaces such as T-piece, tracheostomy collar, and manual resuscitation bag. METHODS: A teaching manikin was intubated with either an ETT (8.0 mm inner diameter) and TT (8 mm inner diameter). Both bronchi were connected to a collecting filter, attached to a sinusoidal pump simulating the breathing pattern of a spontaneously breathing adult (tidal volume 450 mL, respiratory rate 20 breaths/min, inspiratory-expiratory ratio 1:2). Albuterol sulfate (2.5 mg/3 mL) was nebulized through a jet nebulizer, using each airway and interface as appropriate (n = 3). Drug on the filter was eluted and analyzed with spectrophotometry, and expressed as mean percent of loaded dose delivered. Descriptive statistics, the Student t test, and one-way analysis of variance were applied. RESULTS: A greater percentage of nominal dose was delivered via TT than ETT with both T-piece (13.79 ± 2.59% vs 9.05 ± 0.70%) and manual resuscitation bag (45.75 ± 1.8% vs 27.23 ± 8.98%, P = .038 and P = .025, respectively). Use of manual resuscitation bag with both TT and ETT increased lung dose more than 3-fold. Inhaled dose with tracheostomy collar was (6.92 ± 0.81%) less than T-piece with TT (P = .01). CONCLUSION: In this adult model of spontaneous ventilation, aerosol therapy through ETT was less efficient than TT, while the manual resuscitation bag was more efficient than T-piece or tracheostomy collar.

An inexpensive, easily constructed, reusable task trainer for simulating ultrasound-guided pericardiocentesis.

BACKGROUND: Pericardiocentesis is a low-frequency, high-risk procedure integral to the practice of emergency medicine. Ultrasound-guided pericardiocentesis is the preferred technique for providing this critical intervention. Traditionally, emergency physicians learned pericardiocentesis in real time, at the bedside, on critically ill patients. Medical education is moving toward simulation for training and assessment of procedures such as pericardiocentesis because it allows learners to practice time-sensitive skills without risk to patient or learner. The retail market for models for pericardiocentesis practice is limited and expensive. DISCUSSION: We have developed an ultrasound-guided pericardiocentesis task trainer that allows the physician to insert a needle under ultrasound guidance, pierce the "pericardial sac" and aspirate "blood." Our model can be simply constructed in a home kitchen, and the overall preparation time is 1 h. Our model costs $20.00 (US, 2008). Materials needed for the construction include 16 ounces of plain gelatin, one large balloon, one golf ball, food coloring, non-stick cooking spray, one wooden cooking skewer, surgical iodine solution, and a 4-quart sized plastic food storage container. Refrigeration and a heat source for cooking are also required. Once prepared, the model is usable for 2 weeks at room temperature and may be preserved an additional week if refrigerated. When the model shows signs of wear, it can be easily remade, by simply recycling the existing materials. CONCLUSION: The self-made model was well liked by training staff due to accessibility of a simulation model, and by learners of the technique as they felt more at ease performing pericardiocentesis on a live patient.

In vitro comparison of heliox and oxygen in aerosol delivery using pediatric high flow nasal cannula.

Drug administration via high flow nasal cannula (HFNC) has been described in pediatrics but the amount of albuterol delivery with an HFNC is not known. The purpose of this study is to quantify aerosol delivery with heliox and oxygen (O(2)) in a model of pediatric ventilation. A vibrating mesh nebulizer (Aeroneb Solo, Aerogen) was placed on the inspiratory inlet of a heated humidifier and heated wire circuit attached to a pediatric nasal cannula (Optiflow, Fisher & Paykel). Breathing parameters were tidal volume (V(t)) 100 ml, respiratory rate (RR) 20/min, and I-time of 1 sec. Albuterol sulfate (2.5 mg/3 ml) was administered through a pediatric HFNC with O(2) (100%) and heliox (80/20% mixture). A total of 12 runs, using O(2) and heliox were conducted at 3 and 6 L/min (n = 3). Drug was collected on an absolute filter, eluted and measured using spectrophotometry. The percent inhaled dose (mean ± SD) was similar with heliox and O(2) at 3 L/min (11.41 ± 1.54 and 10.65 ± 0.51, respectively; P = 0.465). However at 6 L/min drug deposition was ≥ 2-fold greater with heliox (5.42 ± 0.54) than O(2) (1.95 ± 0.50; P = 0.01). Using a pediatric model of HFNC, reducing delivered flow from 6 to 3 L/min increased inhaled albuterol delivery ≥ 2-fold but eliminated the increase in inhaled drug efficiency associated with heliox.

Influence of nebulizer type, position, and bias flow on aerosol drug delivery in simulated pediatric and adult lung models during mechanical ventilation.

BACKGROUND: The effectiveness of aerosol drug delivery during mechanical ventilation is influenced by the patient, ventilator, and nebulizer variables. The impact of nebulizer type, position on the ventilator circuit, and bias flow on aerosol drug delivery has not been established for different age populations. OBJECTIVE: To determine the influence of nebulizer position and bias flow with a jet nebulizer and a vibrating-mesh nebulizer on aerosol drug delivery in simulated and mechanically ventilated pediatric and adult patients. METHOD: Albuterol sulfate (2.5 mg) was nebulized with a jet nebulizer and a vibrating-mesh nebulizer, using simulated pediatric and adult lung models. The 2 nebulizer positions were: (1) jet nebulizer placed 15 cm from the Y-piece adapter, and vibrating-mesh nebulizer attached directly to the Y-piece; and (2) jet nebulizer placed prior to the heated humidifier with 15 cm of large-bore tubing, and vibrating-mesh nebulizer positioned at an inlet to the humidifier. A ventilator with a heated humidifier and ventilator circuit was utilized in both lung models. The adult ventilator settings were V(T) 500 mL, PEEP 5 cm H2O, respiratory rate 20 breaths/min, peak inspiratory flow 60 L/min, and descending ramp flow waveform. The pediatric ventilator settings were V(T) 100 mL, PEEP 5 cm H2O, respiratory rate 20 breaths/min, inspiratory time 1 s. We tested bias flows of 2 and 5 L/min. The adult and pediatric lung models used 8-mm and 5-mm inner-diameter endotracheal tubes, respectively. Each experiment was run 3 times (n = 3). The albuterol sulfate was eluted from the filter and analyzed via spectrophotometry (276 nm). RESULTS: Nebulizer placement prior to the humidifier increased drug delivery with both the jet nebulizer and the vibrating-mesh nebulizer, with a greater increase with the vibrating-mesh nebulizer. Higher bias flow reduced drug delivery. Drug delivery with the vibrating-mesh nebulizer was 2-4-fold greater than with the jet nebulizer at all positions (P < .05) in both lung models. CONCLUSION: During simulated mechanical ventilation in pediatric and adult models, bias flow and nebulizer type and position impact aerosol drug delivery.

Hybrid simulation combining a high fidelity scenario with a pelvic ultrasound task trainer enhances the training and evaluation of endovaginal ultrasound skills.

OBJECTIVES: In this study, an endovaginal ultrasound (US) task trainer was combined with a high-fidelity US mannequin to create a hybrid simulation model. In a scenario depicting a patient with ectopic pregnancy and hemorrhagic shock, this model was compared with a standard high-fidelity simulation during training sessions with emergency medicine (EM) residents. The authors hypothesized that use of the hybrid model would increase both the residents' self-reported educational experience and the faculty's self-reported ability to evaluate the residents' skills. METHODS: A total of 45 EM residents at two institutions were randomized into two groups. Each group was assigned to one of two formats involving an ectopic pregnancy scenario. One format incorporated the new hybrid model, in which residents had to manipulate an endovaginal US probe in a task trainer; the other used the standard high-fidelity simulation mannequin together with static photo images. After finishing the scenario, residents self-rated their overall learning experience and how well the scenario evaluated their ability to interpret endovaginal US images. Faculty members reviewed video recordings of the other institution's residents and rated their own ability to evaluate residents' skills in interpreting endovaginal US images and diagnosing and managing the case scenario. Visual analog scales (VAS) were used for the self-ratings. RESULTS: Compared to the residents assigned to the standard simulation scenario, residents assigned to the hybrid model reported an increase in their overall educational experience (Delta VAS = 10, 95% confidence interval [CI] = 4 to 18) and felt the hybrid model was a better measure of their ability to interpret endovaginal US images (Delta VAS = 17, 95% CI = 7 to 28). Faculty members found the hybrid model to be better than the standard simulation for evaluating residents' skills in interpreting endovaginal US images (Delta VAS = 13, 95% CI = 6 to 20) and diagnosing and managing the case (Delta VAS = 10, 95% CI = 2 to 18). Time to reach a diagnosis was similar in both groups (p = 0.053). CONCLUSIONS: Use of a hybrid simulation model combining a high-fidelity simulation with an endovaginal US task trainer improved residents' educational experience and improved faculty's ability to evaluate residents' endovaginal US and clinical skills. This novel hybrid tool should be considered for future education and evaluation of EM residents.

High fidelity simulation can discriminate between novice and experienced residents when assessing competency in patient care.

BACKGROUND: High fidelity (HF) simulators have become more common in residency training programs. AIMS: We hypothesized that high fidelity (HF) simulation-based assessment of patient care competency could differentiate novice from experienced residents. METHODS: Prospective study of 44 emergency medicine residents. A simulated case of anaphylactic shock was administered to each participating resident utilizing a HF patient simulator. Management of the case required epinephrine, airway management including a surgical airway, and i.v. fluids. Data was recorded using a standardized form and stop watch. PRIMARY OUTCOME: Time to completion of surgical airway. SECONDARY OUTCOMES: Times to administration of epinephrine/attempt intubation/start surgical airway/complete case; checklist items: epinephrine as first action, pre-oxygenation, cricoid pressure and type of surgical airway. RESULTS: Novice residents took significantly longer than the experienced residents to achieve our primary outcome, time to completion of surgical airway (621/512 sec; p = 0.03). The novice residents took significantly longer to achieve three of our secondary outcomes: time to start of surgical airway (534 versus 442 sec; p = 0.04), time to case completion (650 versus 513 sec; p = 0.006), and epinephrine as a first action (73% versus 100%; p = 0.02). CONCLUSIONS: HF simulation-based assessment using objective measures, particularly time to action, discerned our novice from our experienced residents.

Blood transfusion in critically injured patients: a prospective study.

BACKGROUND: Despite evolving evidence that transfusion risks outweigh benefits in some patients, the critically injured continue to receive large quantities of blood. The present study evaluated patterns of red blood cell transfusions and risk factors for transfusions at various stages of admission in trauma patients. STUDY DESIGN: Prospective, observational study of transfusion practices in patients (n = 120) admitted to a single Level 1 academic trauma centre. Patients were expected to remain in the surgical intensive care unit for greater than 48 h. RESULTS: Patients had a mean age of 34.1+/- 16.0 years, a mean injury severity score (ISS) of 21.5 +/- 9.5, and were equally distributed by major injury type (48% blunt, 52% penetrating). One hundred and four patients (87%) received a total of 324 transfusions, 20 (6%) of which were given in the emergency room, 186 (57%) in the SICU, 22 (7%) post-SICU and 96 (30%) in the operating room. The mean volume of blood per patient transfused was 3144 +/- 2622 mL. One hundred and one patients received an allogeneic transfusion (mean volume 3126 +/- 2639 mL) and 10 patients received an autotransfusion (844 +/- 382 mL). The mean pre-transfusion Hb level was 9.1 +/- 1.4 g/dL. Transfusion volumes correlated with injury severity score (p = 0.011). Patients with an admission Hb < or =12 g/dL or age >55 years were at significant risk to receive increased transfusions (P < .001 and P = .035, respectively). An admission Hb < or =12 g/dL and any mention of long bone orthopedic operations or laparotomy or thoracotomy were associated with increased risk of blood transfusion during the first week of admission. Logistic regression analysis identified transfusion of >4 units of blood as a significant risk factor for SIRS. After 1 week of ICU stay, ISS > 20 and blunt injury were associated with increased risk of transfusion. CONCLUSIONS: Trauma patients are heavily transfused with allogeneic blood throughout the course of their hospital stay and transfusions are administered at relatively high pre-transfusion haemoglobin levels (mean of 9 g/dL). Transfusion of >4 units of blood is an independent risk factor for SIRS. Strategies to limit blood transfusions should be investigated in this population.

Gender and the council of emergency medicine residency directors standardized letter of recommendation.

OBJECTIVES: Until 2002, the Council of Emergency Medicine Residency Directors standardized letter of recommendation (SLOR) prompted authors to predict how an applicant would rank on their match list. A ranking of guaranteed match (GM) was identified as the least common superlative response on the SLOR. That knowledge allowed precise identification of the best SLORs. The authors correlated GM with every possible author/applicant gender combination. METHODS: This was a retrospective, observational study of 835 SLORs submitted in the 1998-1999 and 1999-2000 application cycles to one emergency medicine residency program. A standardized data collection instrument was used. Author/applicant gender combinations (M/M, M/F, F/F, F/M, M/M + F/F, and M/F + F/M) were analyzed with respect to GM by chi-square test, odds ratios with 95% confidence intervals, and logistic regression. RESULTS: There was a statistically significant association between a female-authored/female-applicant SLOR and GM, with a female applicant two times more likely to get a GM from a female author than any other author/applicant gender combination (odds ratio, 2.0; 95% confidence interval = 1.1 to 3.8; p = 0.023). No other combination was significantly associated with GM. CONCLUSIONS: Female applicants to the authors' emergency residency program had a two times better chance of receiving a GM recommendation on a SLOR written by a female faculty member compared with any other possible gender combination of applicants and letter authors. Although the choice of GM has now been eliminated from the SLOR, the role of gender in relation to the SLOR merits further study.