Placement of syringe infusion pumps and solution density can impact infusion performance: An experimental study

AimTo verify how variations in the height and solution density can influence syringe infusion pumps accuracy.MethodsThree syringe infusion pumps were studied in two infusion rates 0.5 ml/h and 10.0 ml/h. The solutions studied were saline solution and parenteral nutrition. The syringe infusion pumps were placed at the level of the distal exit of the infusion line, 30 cm above and 30 cm below.ResultsAfter 2 h of infusion, loss of accuracy was verified mainly at 0.5 ml/h with a significant influence of infusion pump placement (p < 0.001). At 10.0 ml/h there were differences between saline solution and parenteral nutrition at the same level (p < 0.004) and 30 cm above (p < 0.001). After 2 h of infusion the higher error rate identified was 20.1%.ConclusionThe placement of the syringe infusion pump and the infusion rate influence accuracy mainly at 30 cm below and 0,5 ml/h.     

Can Altering Grip Technique and Bag Size Optimize Volume Delivered with Bag-Valve-Mask by Emergency Medical Service Providers?

Introduction: Emergency Medical Services (EMS) professionals rely on the bag-valve-mask (BVM) to provide life-saving positive-pressure ventilation in the prehospital setting. Multiple emergency medicine and critical care studies have shown that lung-protective ventilation protocols reduce morbidity and mortality. A recent study has shown that the volumes typically delivered by EMS professionals with the adult BVM are often higher than recommended by lung-protective ventilation protocols. Our primary objective was to determine if a group of EMS professionals could reduce the volume delivered by adjusting the way the BVM was held. Secondary objectives included 1) if the adjusted grip allowed for volumes more consistent with lung-protection ventilation strategies and 2) comparing volumes to similar grip strategies used with a smaller BVM. Methods: A patient simulator of a head and thorax was used to record respiratory rate, tidal volume, peak pressure, and minute volume delivered by participants for 1?minute each across 6 different scenarios: 3 different grips (using the thumb and either 3 fingers, 2 fingers, or one finger) with 2 different sized BVMs (adult and pediatric). Trials were randomized by blindly selecting a paper with the scenario listed. A convenience sample of EMS providers was used based on EMS provider and research staff availability. Results: We enrolled 50 providers from a large, busy, urban hospital-based EMS agency a mean 8.60 (SD = 9.76) years of experience. Median volumes for each scenario were 836.0?mL, 834.5?mL, and 794?mL for the adult BMV (p?=?0.003); and 576.0?mL, 571.5?mL, and 547.0?mL for the pediatric BVM (p?<?0.001). Across all 3 grips, the pediatric BVM provided more breaths within the recommended volume range for a 70?kg patient (46.4% vs. 0.4%; p?<?0.001) with only a 1.1% of breaths below the recommended tidal volume. Conclusion: The study suggests that it is possible to alter the volume provided by the BVM by altering the grip on the BVM. The tidal volumes recorded with the pediatric BVM were above recommended range in 2 of the 3 grips. The volumes of the pediatric BVM were overall more consistent with lung-protective ventilation volumes when compared to all 3 finger-grips of the adult BVM.     

Determining safe teaching board heights through electromyographic analysis of the shoulder muscles

BackgroundAdjustable teaching boards have been recommended as an ergonomic practice geared at reducing the incidences of teaching-related shoulder musculoskeletal disorders among teachers. However, there are no standards guiding choice of appropriate teaching board heights. This study was aimed at evaluating shoulder muscle activities in response to five teaching board heights.MethodsThirty participants performed writing activities on five different board heights (Diff10 = standing height minus 10% of standing height; NormH = participant's standing height; Sum10 = standing height plus 10% of standing height; Sum20 = standing height plus 20% of standing height; Sum25 = standing height plus 25% of standing height). Electromyographic analysis of the anterior deltoid (AD), upper trapezius (UT), serratus anterior (SA) and pectoralis major (PM) muscles were performed simultaneously during each task. Data were analyzed with one-way ANOVA and independent T-test at p < 0.05.ResultsSum20 board height significantly (p < 0.001) elicited the highest activities in the AD (19.35 ± 11.26%) and UT (29.06 ± 29.53%) muscles while SA (20.37 ± 10.87%) and PM (20.86 ± 12.17%) muscles were most active at Sum25 board height. SA and PM muscles progressively increased with increasing board heights while AD and UT muscles showed alternating patterns of activation at increasing board heights. For safe ergonomic practices, recommended teaching board heights should be within the range of NormH and Sum10.ConclusionExtremely high or low teaching boards have tendencies of inducing musculoskeletal shoulder discomforts.     

Can EMS Providers Provide Appropriate Tidal Volumes in a Simulated Adult-sized Patient with a Pediatric-sized Bag-Valve-Mask?

Introduction: In the prehospital setting, Emergency Medical Services (EMS) professionals rely on providing positive pressure ventilation with a bag-valve-mask (BVM). Multiple emergency medicine and critical care studies have shown that lung-protective ventilation protocols reduce morbidity and mortality. Our primary objective was to determine if a group of EMS professionals could provide ventilations with a smaller BVM that would be sufficient to ventilate patients. Secondary objectives included 1) if the pediatric bag provided volumes similar to lung-protective ventilation in the hospital setting and 2) compare volumes provided to the patient depending on the type of airway (mask, King tube, and intubation). Methods: Using a patient simulator of a head and thorax that was able to record respiratory rate, tidal volume, peak pressure, and minute volume via a laptop computer, participants were asked to ventilate the simulator during six 1-minute ventilation tests. The first scenario was BVM ventilation with an oropharyngeal airway in place ventilating with both an adult- and pediatric-sized BVM, the second scenario had a supraglottic airway and both bags, and the third scenario had an endotracheal tube and both bags. Participants were enrolled in convenience manner while they were on-duty and the research staff was able to travel to their stations. Prior to enrolling, participants were not given any additional training on ventilation skills. Results: We enrolled 50 providers from a large, busy, urban fire-based EMS agency with 14.96 (SD = 9.92) mean years of experience. Only 1.5% of all breaths delivered with the pediatric BVM during the ventilation scenarios were below the recommended tidal volume. A greater percentage of breaths delivered in the recommended range occurred when the pediatric BVM was used (17.5% vs 5.1%, p < 0.001). Median volumes for each scenario were 570.5mL, 664.0mL, 663.0mL for the pediatric BMV and 796.0mL, 994.5mL, 981.5mL for the adult BVM. In all three categories of airway devices, the pediatric BVM provided lower median tidal volumes (p < 0.001). Conclusion: The study suggests that ventilating an adult patient is possible with a smaller, pediatric-sized BVM. The tidal volumes recorded with the pediatric BVM were more consistent with lung-protective ventilation volumes.     

Intraosseous access in the prehospital setting: literature review

BACKGROUND: Although the majority of Australian intensive care paramedics use the manual intraosseous infusion technique (MAN-IO), several other semiautomatic devices now are available, such as the bone injection gun (BIG) and the semiautomatic intraosseous infusion system (EZ-IO). Given the choice of devices now available, questions have been raised regarding success rates, accuracy, decay of skills, and adverse events. OBJECTIVES: Review the literature regarding the use of intraosseous (IO) devices in the prehospital setting. METHODS: Selected electronic databases (Medline, Embase, and CINAHL) were searched, and a hand search was conducted for grey-literature that included studies from the commencement of the process to the end of May 2010. Inclusion criteria were any study reporting intraosseous insertion and/or infusion (adult and pediatric) by paramedics in the prehospital setting. Findings The search located 2,100 articles; 20 articles met the inclusion criteria. The review also noted that use of IO access (regardless of technique) offers a safe and simple method for gaining access to the patients' vascular system. A number of studies found that the use of semiautomatic devices offers better and faster intraosseous access compared with the use of manual devices, and also were associated with fewer complications. The findings also suggest that the use of semiautomatic devices can reduce insertion times and the number of insertion attempts when contrasted with the use of manual insertion techniques. Despite these findings, statistically no specific IO device has proven clinical superiority. Conclusion While manual IO techniques currently are used by the majority of Australian paramedics, the currently available evidence suggests that semiautomatic devices are more effective. Further research, including cost-benefit analyses, is required at a national level to examine skill acquisition, adverse effects, and whether comparative devices offer clinically significant advantages. Olaussen A , Williams B . Intraosseous access in the prehospital setting: literature review. Prehosp Disaster Med. 2012;27(5):1-5.     

MRI测量正常成人胸腰段椎体高度

目的 比较和分析正常成人胸腰段椎体高度和比值在两性间和随年龄增长的差异。方法 应用6点测量法在正中矢状位T1WI 上测量1020名正常成人T12~L3椎体前、中、后径高度,并计算中径/后径、前径/后径比值。分别应用t检验及单因素方差分析比较和分析同年龄组不同性别间和相同性别不同年龄组间椎体高度和比值的差异。结果 两性T12~L3椎体前、中、后径,男性T12~L2椎体中径/后径的数值总体上随年龄增加而递减。男性在各年龄组的T12~L3椎体前、中、后径均高于女性组,女性T12~L3椎体前径/后径的比值总体上高于男性;椎体中径/后径男女性之间总体上差别较小。结论 获得了不同年龄男性、女性正常成人T12~L3椎体高度及比值的MRI测量参考值;MRI测量脊椎准确性高,值得推广。     

Strategies Used by Prehospital Providers to Overcome Language Barriers

Objective: Language barriers are commonly encountered in the prehospital setting but there is a paucity of research on how prehospital providers address language discordance. We sought to identify the communication strategies, and the limitations of those strategies, used by emergency medical services (EMS) providers when confronted with language barriers in a variety of linguistic and cultural contexts. Methods: EMS providers were queried regarding communication strategies to overcome language barriers as part of an international, multi-site, sequential explanatory, qualitative-predominant, mixed methods study of prehospital language barriers. A survey of EMS telecommunicators was administered at dispatch centers in New Mexico (United States) and Western Cape (South Africa). Semi-structured qualitative interviews of EMS field providers were conducted at agencies who respond to calls from participating dispatch centers. Survey data included quantitative data on demographics and communication strategies used to overcome language barriers as well as qualitative free-text responses on the limitations of strategies. Interviews elicited narratives of encounters with language-discordant patients and the strategies used to communicate. Data from the surveys and interviews were integrated at the point of analysis. Results: 125 telecommunicators (overall response rate of 84.5%) and a purposive sample of 27 field providers participated in the study. The characteristics of participants varied between countries and between agencies, consistent with variations in participating agencies’ hiring and training practices. Telecommunicators identified 3rd-party telephonic interpreter services as the single most effective strategy when available, but also described time delays and frustration with interpreter communications that leads them to preferentially try other strategies. In the field, all providers reported using similar strategies, relying heavily on bystanders, multilingual coworkers, and non-verbal communication. Prehospital providers described significant limitations to these strategies, including time delays, breaches of patient confidentiality, and inaccurate interpretation. Participants suggested various resources to improve communication with language-discordant patients. Conclusions: Prehospital providers rely upon similar, informal strategies for overcoming language barriers across a variety of locations, provider types, and linguistic and cultural contexts.     

Ambulance sphygmomanometers are frequently inaccurate

Objective. To determine the accuracy and reliability of sphygmomanometers used in a metropolitan emergency medical services (EMS) system.

Methods. As a cross-sectional, convenience sample, 150 sphygmomanometers used by EMS personnel in Milwaukee County, Wisconsin, were evaluated. Each sphygmomanometer was checked for accuracy by connecting the manometer to a new, standard mercury manometer using a “Y” connector. Pressure was checked at readings of 60,90,120, and 200 mm Hg. The integrity of the device (leaking) was checked by inflating the cuff around a can to 300 mm Hg and measuring the pressure lost in 1 minute. Devices were determined to be inaccurate if the average of the absolute differences at each pressure deviated by more than 3 mm Hg. The device was determined to be unreliable (leaked) if it lost pressure greater than 15 mm Hg in 1 minute.

Results. Twenty-eight percent (41/149) of the devices were inaccurate at 90 mm Hg and 25% (37/149) were inaccurate overall. The overall and 90 mm Hg average deviations were ±6.6 and ±6.0 mm Hg, respectively. Sixty-three percent (94/150) of the devices were unreliable (leaked). When considering both accuracy and reliability at 90 mm Hg, a total of 73% (109/150) of the devices failed one or both of the criteria.

Conclusion. This study suggests that an accurate blood pressure measurement may not be reliably obtained with 73% of the sphygmomanometers currently used in the county's EMS system.     

Optimal bed height for passive manual tasks

PurposeTo determine bed height adjustment for maintaining neutral lumbar position as a function of anthropometric dimensions.Materials and methods80 physical therapy students performed passive shoulder flexion and straight leg raising tasks on standard versus the adjustable bed. The lumbar angle was measured at the start and finish of tasks. The rate of perceived exertion was measured immediately after each task. The most comfortable bed height in relation to some anatomical landmarks was measured.ResultsMean bed height for shoulder flexion tasks was significantly higher than for straight leg raising. The mean adjusted bed heights for both tasks were significantly higher and with less exertion felt by the participants, compared to the standard bed height (0.715 m). The third knuckle of the hand and the radial styloid process of the wrist were established as the most valuable anthropometric landmarks for bed height adjustment.ConclusionsThe above landmarks are recommended to maintain a neutral lumbar position while adjusting bed heights for manual tasks. Each manual task requires adjustment of the bed height. Further studies are needed to confirm our results.     

I MPROVEMENTS IN P REHOSPITAL M EDICATION S TORAGE P RACTICES IN R ESPONSE TO R ESEARCH

Previously the authors showed that prehospital medications were stored outside their recommended temperature range. In response, the state office of emergency medical services (EMS) issued regulations regarding temperature control and monitoring of prehospital medications. Objective: To determine the impact of previous research (on medication storage conditions) on current practices among the mobile intensive care units (MICUs) within the state. Methods: A statewide, structured telephone survey of MICU directors was conducted between April and December 2000. Questions focused on changes in storage and monitoring practices (including modifications to vehicles, medication boxes, and the use of temperature monitoring devices) since the authors' previous research. Results: Thirty-three of 35 (94%) programs (100 vehicles) participated in the survey. Eighty-five percent changed their practices since the research five years ago. Of the five that did not change, three already had temperature control measures in place, while two have not made any changes. Twenty-one (63%) of the programs reported changing specifically because of state regulations. Eighty-one percent of the programs have taken some measure to control temperature. Currently, 63% of the 100 vehicles in use have both heating and cooling devices specifically for the medications, whereas 14% have only a heater and 23% have neither. Thirty-one (94%) MICUs monitor the temperature in some manner: 42% in the vehicle, 58% in the medication box. Of these, 68% are using 30-day electronic temperature data recorders, whereas 32% are using nonrecording digital thermometers. Conclusions: This survey demonstrates a positive impact from previous research. Most of the MICUs in the state have changed their practices in controlling and monitoring prehospital medication storage temperature.     

Safety and cost benefit of an accelerated infliximab infusion protocol in the treatment of ambulatory patients with inflammatory bowel diseases

Background: Infliximab is recommended to be infused over 2 h, but accelerated infusion rates of 30 min may improve efficiency, patient satisfaction and reduce nursing time and cost. The safety of this approach is not established. This study aims to assess the safety of accelerated infliximab infusion and determine the direct cost savings.

Methods: The primary endpoint of the study was adverse events and the secondary endpoints were cost, time saving per infusion and patient satisfaction associated with an accelerated infusion protocol.

Results: One hundred and thirty-six and 342 infusions were administered to 23 and 39 patients in the standard and accelerated protocols, respectively (mean infusion times 150 and 73.4 min, respectively, p < 0.0001). The adverse reaction rate of the standard protocol was 2.2% (95% confidence interval: 0.46 – 6.57) and accelerated protocol was 3.2% (95% CI: 1.74 – 5.73; p = 0.77). The odds ratio of adverse reaction for the 30-min infusion was 0.40 (95% CI: 0.09 – 1.82). The relative direct cost of nursing was decreased by 51.1% per infusion. Patient satisfaction score of the accelerated protocol was 9.2/10 (95% CI: 8.55 – 9.76) compared to 8.5/10 (95% CI: 7.83 – 9.17) in the initiation phase (p = 0.018).

Conclusions: Accelerated 30-min infliximab infusions significantly reduced nursing time, cost and increased patient satisfaction without increasing infusion reactions. Increased patient freedom and improved efficiency in healthcare delivery can be expected.     

A Meta-Analysis of Prehospital Airway Control Techniques Part I: Orotracheal and Nasotracheal Intubation Success Rates

Abstract

Background. Airway management is a key component of prehospital care for seriously ill and injured patients. Although endotracheal intubation has been a commonly performed prehospital procedure for nearly three decades, the safety and efficacy profile of prehospital intubation has been challenged in the last decade. Reported intubation success rates vary widely, and established benchmarks are lacking. Objective. We sought to determine pooled estimates for oral endotracheal intubation (OETI) and nasotracheal intubation (NTI) placement success rates through a meta-analysis of the literature. Methods. We performed a systematic literature search for all English-language articles reporting placement success rates for prehospital intubation. Studies of field procedures performed by prehospital personnel from any nation were included. All titles were reviewed independently by two authors using prespecified inclusion criteria. Pooled estimates of success rates for each airway technique, including drug-facilitated intubation (DFI) and rapid-sequence intubation (RSI), were calculated using a random-effects model. Historical trends were evaluated using meta-regression. Results. Of 2,005 identified titles reviewed, 117 studies addressed OETI and 23 addressed NTI, encompassing a total of 57,132 prehospital patients. There was substantial interrater reliability in the review process (kappa = 0.81). The pooled estimates (and 95% confidence intervals [CIs]) for intervention success for nonphysician clinicians were as follows: overall non-RSI/non-DFI OETI success rate: 86.3% (82.6%–89.4%); OETI for non–cardiac arrest patients: 69.8% (50.9%–83.8%); DFI 86.8% (80.2%–91.4%); and RSI 96.7% (94.7%–98.0%). For pediatric patients, the paramedic OETI success rate was 83.2% (55.2%–95.2%). The overall NTI success rate for nonphysician clinicians was 75.9% (65.9%–83.7%). The historical trend of OETI reflects a 0.49% decline in success rates per year. Conclusions. We provide pooled estimates of placement success rates for prehospital airway interventions. For some patient and clinician characteristics, OETI has relatively low success rates. For nonarrest patients, DFI and RSI appear to increase success rates. Across all clinicians, NTI has a low rate of success, raising questions about the safety and efficacy of this procedure.     

An Urban 9-1-1 System’s Experience with Left Ventricular Assist Device Patients

Background: Left ventricular assist devices (LVADs) are used with increasing frequency and left in place for longer periods of time. Prior publications have focused on the mechanics of troubleshooting the device itself. We aim to describe the epidemiology of LVAD patient presentations to emergency medical services (EMS), prehospital assessments and interventions, and hospital outcomes. Methods: This is a retrospective chart review of known LVAD patients that belong to a single academic center’s heart failure program who activated the 9-1-1 system and were transported by an urban EMS system to one of the center’s 2 emergency departments between January 2012 and December 2015. Identifying demographics were used to query the electronic medical record of the responding city fire agency and contracted transporting ambulance service. Two reviewers abstracted prehospital chief complaint, vital signs, assessments, and interventions. Emergency department and hospital outcomes were retrieved separately. Results: From January 2012 to December 2015, 15 LVAD patients were transported 16 times. The most common prehospital chief complaint was weakness (7/16), followed by chest pain (3/16). Of the 7 patients presenting with weakness, one was diagnosed with a stroke in the emergency department. Another patient was diagnosed with subarachnoid hemorrhage and expired during hospital admission. This was the only death in the cohort. The most common hospital diagnosis was GI bleed (3/16). The overall admission rate was 87.5% (14/16). Conclusions: EMS interactions with LVAD patients are infrequent but have high rates of admission and incidence of life-threatening diagnoses. The most common prehospital presenting symptoms were weakness and chest pain, and most prehospital interactions did not require LVAD-specific interventions. In addition to acquiring technical knowledge regarding LVADs, EMS providers should be aware of non-device-related complications including intracranial and GI bleeding and take this into account during their assessment.     

Prevention of Pediatric Drug Calculation Errors by Prehospital Care Providers

Objective. Calculating weight-based drug doses for pediatric patients is difficult, with significant error potential. In the prehospital setting, few safeguards currently avert pediatric drug administration errors. We sought to determine whether use of a protocol-specific pediatric code card enables prehospital care providers to calculate more consistently accurate weight-based drug doses, volumes of administration, andage-appropriate endotracheal tube sizes. Methods. Questionnaires requiring calculations of medication doses, volumes, andendotracheal tube sizes were administered to prehospital care providers between June andNovember 2006 in fire department continuing education classes in the State of Maryland andthe District of Columbia. Half of the participants performed the calculations with the pediatric code card as an aid, andhalf without. Calculations done by the two groups were compared for rate andextent of errors. We evaluated the error frequency in calculations of pediatric medication doses andendotracheal tube sizes. Results. Of the 523 advanced life support prehospital care providers questioned, 246 answered questions using the pediatric code card, and277 answered questions without using the card. The mean individual percentages of correct responses were 94% for the group aided by the code card and65% for the group unaided by the card (percentage difference, 29%; 95% confidence interval [CI], 25–31%; p < 0.001). Ninety-eight percent of the aided group and23% of the unaided group calculated the correct endotracheal tube size (percentage difference, 75%; 95% CI, 70–81%; p < 0.001). Conclusions. The use of the pediatric code card enabled prehospital care providers to determine weight-based drug doses, volumes of administration, andendotracheal tube sizes more accurately than peers without access to the code card.     

R EVIEW AND S ELF -A SSESSMENT TO A CCOMPANY EMERGENCY MEDICINE

Cardiac arrest in children outside the hospital is associated with high mortality rates. Recent investigations have suggested that the use of advanced life support (ALS) measures by emergency medical services (EMS) personnel may decrease survival. These studies have used the pediatric Utstein style of defining ALS and basic life support (BLS) measures. The pediatric Utstein style defines BLS as “an attempt to restore effective ventilation and circulation” using noninvasive means to open the airway but specifically excludes the use of bag-valve-mask devices. Advanced life support is defined as the “addition of invasive maneuvers to restore effective ventilation and circulation.” The authors of the study described below believe that using this definition would categorize some patients into an ALS group who would otherwise be categorized as having received BLS (i.E., “bag-valve-mask only”). Objective: To compare survival rates among children receiving BLS or ALS following out-of-hospital cardiac arrest using amended definitions of prehospital life support measures. Specifically, the definition of BLS was expanded to include the use of bag-valve-mask devices only. Methods: This was a retrospective chart review in an urban, pediatric emergency department. Patients included all children presenting to the emergency department between January 1, 1986, and December 31, 1999, following out-of-hospital cardiac arrest. The main outcome measure was survival to hospital discharge. Results: Two hundred ten children were identified. Twenty-one patients were excluded from further analysis because of absent or incomplete medical records. One hundred eighty-nine patients were studied. Five children (2.6%) survived to discharge from the hospital. Of 189 children, 39 (20.6%) were provided BLS measures by prehospital personnel; 150 (79.4%) received ALS. There was no significant difference between groups in survival to hospital discharge. Patients who survived to hospital discharge were more likely to be in sinus rhythm upon arrival in the emergency department (p < 0.001) and to have received fewer doses of standard-dose epinephrine in the emergency department (p < 0.001). Conclusion: The use of ALS by prehospital personnel for children with out-of-hospital cardiac arrest did not improve survival to discharge from the hospital when compared with the use of BLS.     

D YSRHYTHMIA R ECOGNITION AND M ANAGEMENT,T HIRD E DITION

Abstract

Objectives. To evaluate whether chest compressions affect the time taken for intubation (TTI) using the Macintosh laryngoscope and two portable video laryngoscopes (VLs) (GlideScope Ranger and Airway Scope) when used by novice prehospital caregivers, and to compare the TTIs and rates of successful intubation among the three laryngoscopes with and without chest compressions in a manikin model. Methods. This was a pilot randomized crossover study. Twenty paramedic students and paramedics who had no clinical experience with tracheal intubation and had never used any of two VLs participated in the study. After a one-hour training session for the VLs, participants performed intubations on a Laerdal Resusci Anne Simulator placed on the floor. Each paramedic used all three laryngoscopes, with the order of usage being randomly assigned. The TTIs and rates of successful intubation among the three laryngoscopes, with and without ongoing chest compressions, were compared. Results. The difference between the TTIs using each laryngoscope with and without chest compressions was not significant (Macintosh: 2.99 sec, p == 0.06; GlideScope Ranger: 2.04 sec, p == 0.11; and Airway Scope: 0.91 sec, p == 0.10). The median TTI using the Airway Scope (15.46 sec) was significantly shorter than those for the Macintosh (24.14 sec) and the GlideScope Ranger (24.12 sec) during chest compressions (p == 0.028 and p == 0.004, respectively). There were no significant differences in the rates of successful intubation among the three laryngoscopes on each condition (without chest compressions, p == 0.15; with chest compressions, p == 0.27), but the cumulative success rates related to the TTI were significantly greater with the Airway Scope than with the other devices in both conditions. Conclusion. In this pilot study, chest compressions did not significantly affect the TTI using the Macintosh laryngoscope and two portable VLs when used by novice prehospital caregivers in the manikin model on the floor. Considering the fairly short training time, two portable VLs may be potentially useful adjuncts for tracheal intubation during chest compressions for novice prehospital caregivers. Further studies are required to validate whether these findings are clinically relevant.     

S UCCESSFUL P REHOSPITAL A IRWAY M ANAGEMENT BY EMT-D S U SING THE C OMBITUBE

Objective. To evaluate the ability to train emergency medical technicians-defibrillation (EMT-Ds) to effectively use the Combitube for intubations in the prehospital environment. Methods. This was an 18-month prospective field study in which EMT-Ds were trained how and in what situations to use the Combitube. Data were then obtained for all patients in whom Combitube insertion was attempted. Indications for use of the Combitube included: unconsciousness without a purposeful response, absence of the gag reflex, apnea or respiratory rate less than 6 breaths/min, age more than 16 years, and height at least 5 feet tall. Contraindications were: obvious signs of death, intact gag reflex, inability to advance the device due to resistance, or known esophageal pathology. Data were entered prospectively from the San Diego County EMS QANet database for prehospital providers. Results. Twenty-two EMT-D provider agencies, involving approximately 500 EMT-Ds, were included as study participants. Combitube insertions were attempted in 195 prehospital patients in cardiorespiratory arrest, with appropriate indication for Combitube use. An overall successful intubation rate (defined as the ability to successfully ventilate) of 79% was observed. Identical success rates for medical and trauma patients were noted. The device was placed in the esophagus 91% of the time. Resistance during insertion was the major reason for unsuccessful Combitube intubations. An overall hospital admission rate of 19% was observed. No complications were reported. Conclusion. EMT-Ds can be trained to use the Combitube as a means of establishing an airway in the pre-hospital setting. Future studies will need to further evaluate its effect on patient outcome.     

Do manual chest compressions provide substantial ventilation during prehospital cardiopulmonary resuscitation?

IntroductionChest compressions have been suggested to provide passive ventilation during cardiopulmonary resuscitation. Measurements of this passive ventilatory mechanism have only been performed upon arrival of out-of-hospital cardiac arrest patients in the emergency department. Lung and thoracic characteristics rapidly change following cardiac arrest, possibly limiting the effectiveness of this mechanism after prolonged resuscitation efforts. Goal of this study was to quantify passive inspiratory tidal volumes generated by manual chest compression during prehospital cardiopulmonary resuscitation.Materials and methodsA flowsensor was used during adult out-of-hospital cardiac arrest cases attended by a prehospital medical team. Adult, endotracheally intubated, non-traumatic cardiac arrest patients were eligible for inclusion. Immediately following intubation, the sensor was connected to the endotracheal tube. The passive inspiratory tidal volumes generated by the first thirty manual chest compressions performed following intubation (without simultaneous manual ventilation) were calculated.Results10 patients (5 female) were included, median age was 64 years (IQR 56, 77 years). The median compression frequency was 111 compression per minute (IQR 107, 116 compressions per minute). The median compression depth was 5.6 cm (IQR 5.4 cm, 6.1 cm). The median inspiratory tidal volume generated by manual chest compressions was 20 mL (IQR 13, 28 mL).ConclusionUsing a flowsensor, passive inspiratory tidal volumes generated by manual chest compressions during prehospital cardiopulmonary resuscitation, were quantified. Chest compressions alone appear unable to provide adequate alveolar ventilation during prehospital treatment of cardiac arrest.     

Reference intervals and diagnostic ranges for serum free κ and free λ immunoglobulin light chains vary by instrument platform: Implications for classification of patient results in a multi-center study

BackgroundSerum free light chain (FLC) immunoglobulins are key biomarkers that aid in the diagnosis, prognosis and assessment of treatment response in patients with plasma cell disorders (PCD). Here we investigated the transference of manufacturer's reported κFLC, λFLC and κ to λ FLC reference intervals (RI) and established de novo FLC RI and diagnostic ranges on four instruments at three academic medical centers. In addition, we also compared the classification of patient FLC results using manufacturer's versus established RIs and diagnostic ranges.MethodsCLSI EP28-A3C protocol was applied to investigate transference and establishment of FLC reference intervals on the cobas (Roche), Immage (Beckman), Optilite and SPA Plus (Binding Site). Serum κ FLC and λ FLC were measured in reference sera (N = 126) with estimation of central 95% RIs and FLC ratio diagnostic range (total range). Frequencies (%) in patient FLC results (N > 380 per institution) classified above, below or within manufacturer's versus established FLC RI were compared.ResultsThree of four instrument platforms did not exhibit acceptable transference of manufacturer's reported κ FLC RI. The manufacturer's reported FLC total diagnostic range did not encompass all values observed in reference sera for any of the four platforms evaluated. Established FLC ratio diagnostic ranges reduced the frequency of patient results classified above range for three of four platforms evaluated.ConclusionsTransference of manufacturer's reported FLC RIs may be inappropriate for select instrument platforms. De novo establishment of FLC RIs specific to instrument platform is highly recommended in order to assure correct patient result classification.