Stewardship of Prehospital Low Titer O-Positive Whole Blood in a Large Urban Fire-Based EMS System

Introduction: Trauma is the leading cause of death for those aged 1 to 46 years with most fatalities resulting from hemorrhage prior to arrival to hospital. Hemorrhagic shock patients receiving transfusion with 15 minutes experience lower mortality. Prehospital blood transfusion has many legal, fiduciary, and logistical issues. The San Antonio Fire Department participates in a consortium designed to enhance the stewardship of prehospital whole blood. This study aimed to stratify blood usage amongst the field supervisors and special operations units that carry whole blood. Methods: This was a 12-month retrospective analysis of blood usage. Blood tracking forms (used for either blood exchange of transfusion) were cross referenced with city financial records to determine blood usage patterns in the 7th Largest City in the US. We used descriptive statistics, compared usage ratios, and chi-square to compare dichotomized data. Results: A total of 363 whole blood units were obtained and 248 (68.3%) units of whole blood were transfused. EMS field supervisors transfused 74% of whole blood vs. 44% for special operations ambulances (p= <0.001). Response vehicles located in densely populated areas had the highest usage rates. All blood units were either transfused or returned for a zero blood unit wastage for expiration. Conclusion: The information contained within this work can provide other EMS agencies with a basic framework for comparison. The data from the SAFD's whole blood transfusion rate coupled with the clinical transfusion guideline has provided some insight for prospective agencies considering adopting a whole blood program. EMS systems and municipalities with similar characteristics can project their own whole blood needs and make informed decisions regarding program feasibility and design.

Distal femur versus humeral or tibial IO, access in adult out of hospital cardiac resuscitation

BACKGROUND

Intraosseous (IO) vascular access is a well-established method for fluid and drug administration in the critically ill. The Food and Drug Administration has approved adult IO access at the proximal humerus, proximal tibia, and the sternum; all three sites have significant limitations. The Distal Femur is away from the chest, with high flow rates. The objective of this study was to evaluate the distal femur site during resuscitation of adult out-of-hospital cardiac arrest.

METHODS

A retrospective analysis of adult out of hospital cardiac arrest patients treated by the San Antonio Fire Department. IO access was obtained by first-responders (paramedics or EMT-basic) or EMS paramedics. All resuscitation attempts from 2017 to 2018 data were analyzed. The protocol did not dictate the preference of IO site. The primary measure: number of OHCA patients in each subgroup: IO femur, IO humerus, IO tibia. Secondary measures: paramedic or basic operator, dislodgement rate, and total fluid infused.

RESULTS

There were 2,198 patients meeting inclusion criteria: 888 femur, 696 humerus, 432 tibia. Distal femur increased 2.5 times in the 2018 cohort compared to the 2017 cohort, with a corresponding decrease in humerus (factor of 0.29). Proximal tibia remained unchanged. Dislodgement rates and total infusion (ml) remained unchanged.

CONCLUSIONS

The distal femur IO was feasible and associated with similar measured performance parameters as other IO sites in adult OHCA for both advanced and basic life support personnel.

More sophisticated than a drink cooler or an old sphygmomanometer but still not adequate for prehospital blood: A market review of commercially available equipment for prehospital blood transport and administration

BACKGROUND

Hemorrhage is the leading cause of death in trauma patients with most fatalities occurring before reaching a higher level of care-this applies to both the civilian setting and the military combat setting. Hemostatic resuscitation with increased emphasis on blood transfusion while limiting use of crystalloids has become routine in trauma care. However, the prehospital setting-especially in combat-presents unique challenges with regard to storage, transport, and administration. We sought to evaluate available technology on the market for storage and administration technology that is relevant to the prehospital setting.

STUDY DESIGN AND METHODS

We conducted a market review of available technology through subject-matter expert inquiry, reviews of published literature, reviews of Federal Drug Administration databases, internal military publications, and searches of Google.

RESULTS

We reviewed and described a total of 103 blood transporters, 22 infusers, and 6 warmers.

CONCLUSIONS

The risk of on-scene fatality in trauma patients and recent developments in trauma care demonstrate the need for prehospital transfusion. These transfusions have been logistically prohibited in many operations. We have reviewed the current commercially available equipment and recommended pursuit of equipment that improves accessibility to field transfusion. Current technology has limited applicability for the prehospital setting and is further limited for the military setting.

Operationalizing the Deployment of Low-Titer O-Positive Whole Blood Within a Regional Trauma System

INTRODUCTION

The implementation of a low-titer O+ whole blood (LTOWB) resuscitation algorithm, particularly in the prehospital environment, has several inherent challenges, including cost, limited and inconsistent supply, and the logistics of cold-chain management. The Southwest Texas Regional Advisory Council has implemented the nation's first multidisciplinary, multi-institutional regional LTOWB program. This research effort was to illustrate the successful deployment of LTOWB within a regional trauma system.

MATERIALS AND METHODS

A deliberate systems approach to the deployment of LTOWB was used. Tenets of this program included the active management of blood donor sources and blood supply levels to minimize wastage as a result of expiration, maximize product utilization, the use of prehospital transfusion triggers, and efforts to decrease program costs prehospital agencies. A novel LTOWB rotation system was established using the concept of a "rotation site" and "rotation center." Standardized transfusion criteria, a regional approved equipment list, a regional Prehospital Blood Product Transfusion Record, and a robust multilevel communication plan serves as the framework for the program. The San Antonio Whole Blood Consortium was developed to create a consensus driven forum to manage and guide the program.

RESULTS

From January 2018 to October 2019, LTOWB has been placed at 18 helicopter emergency medical services (HEMS) bases, 12 ground emergency medical service (EMS) agencies, 1 level I trauma center, and 1 level IV trauma center. A total of 450 patients have received a prehospital LTOWB transfusion. Program wide, the wastage rate of LTOWB due to expiration is between 1% and 2%. No complications related to prehospital LTOWB administration have been identified.

DISCUSSION

This work demonstrates a novel model for the development of a trauma system LTOWB program. The program's implementation augments remote damage control resuscitation strategies and requires the integration and collaboration of a multidisciplinary stakeholder team to optimize efficiency, performance, and safety of the program.

Paramedic utilization of Vision, Aphasia, Neglect (VAN) stroke severity scale in the prehospital setting predicts emergent large vessel occlusion stroke

BACKGROUND

Numerous stroke severity scales have been published, but few have been studied with emergency medical services (EMS) in the prehospital setting. We studied the Vision, Aphasia, Neglect (VAN) stroke assessment scale in the prehospital setting for its simplicity to both teach and perform. This prospective prehospital cohort study was designed to validate the use and efficacy of VAN within our stroke systems of care, which includes multiple comprehensive stroke centers (CSCs) and EMS agencies.

METHODS

The performances of VAN and the National Institutes of Health Stroke Scale (NIHSS) ≥6 for the presence of both emergent large vessel occlusion (ELVO) alone and ELVO or any intracranial hemorrhage (ICH) combined were reported with positive predictive value, sensitivity, negative predictive value, specificity, and overall accuracy. For subjects with intraparenchymal hemorrhage, volume was calculated based on the ABC/2 formula and the presence of intraventricular hemorrhage was recorded.

RESULTS

Both VAN and NIHSS ≥6 were significantly associated with ELVO alone and with ELVO or any ICH combined using χ² analysis. Overall, hospital NIHSS ≥6 performed better than prehospital VAN based on statistical measures. Of the 34 cases of intraparenchymal hemorrhage, mean±SD hemorrhage volumes were 2.5±4.0 mL for the five VAN-negative cases and 17.5±14.2 mL for the 29 VAN-positive cases.

CONCLUSIONS

Our VAN study adds to the published evidence that prehospital EMS scales can be effectively taught and implemented in stroke systems with multiple EMS agencies and CSCs. In addition to ELVO, prehospital scales such as VAN may also serve as an effective ICH bypass tool.

Abstract TP262: Pre-Hospital VAN Large Vessel Occlusion Screening Tool Predicts Larger Intracerebral Hemorrhage

Introduction: An EMS validation study in San Antonio, Texas previously evaluated the Vision Aphasia Neglect (VAN) screen to identify large vessel occlusion (LVO) in the prehospital setting. Because it may be used in the field to bypass hospitals for higher level care, VAN’s performance with stroke mimics, specifically intracerebral hemorrhage (ICH), is important in stroke systems of care. The goal of this study was to determine if a positive VAN assessment correlated with larger ICH.

Methods: Paramedics from two San Antonio EMS agencies documented a VAN assessment from June 2017 to April 2019 for all EMS stroke alerts less than 6 hours from last known well. The prehospital VAN score, emergency department advanced neuroimaging interpretation, and hospital discharge diagnosis were collected from three comprehensive stroke centers. Stroke mimics and hemorrhages were included. ICH volume, location, and presence of intraventricular hemorrhage (IVH) were recorded. ICH volume and location were dichotomized by the median value and infratentorial versus supratentorial, respectively. Descriptive statistics were used for continuous data, and categorical data was analyzed by Fisher’s exact test.

Results: VAN scores were recorded for 215 EMS activated stroke alerts, of which 131 (60.9%) were VAN positive and 23 (10.7%) were ICH. All were hypertensive etiologies except one arteriovenous malformation related hemorrhage. ICH mean and median values were 15.3 ml and 10.3 ml (range 0.3 - 51 ml), respectively. Of the 23 ICH cases, IVH was present in 7 (30%), and infratentorial location was noted in 4 (17%). Fisher’s exact test for VAN and ICH (categorized as ≥ or < median volume) was significant (0.027, p<0.05). However, VAN versus both ICH location and presence of IVH was non-significant.

Conclusion: In this prospective EMS validation study, a pre-hospital VAN positive assessment predicted larger ICH volumes. Although VAN was designed to identify LVO, pre-hospital triage of ICH is an additional benefit of this screening tool. A false positive VAN assessment for LVO may signify a larger ICH, which is often transferred to higher level centers as standard of care. Thus, VAN perform well for both ischemic and hemorrhagic hospital bypass protocols.

Prehospital Battlefield Casualty Intervention Decision Cognitive Study

INTRODUCTION

Airway compromise is the third most common cause of preventable battlefield death. Surgical cricothyroidotomy (SC) is recommended by Tactical Combat Casualty Care (TCCC) guidelines when basic airway maneuvers fail. This is a descriptive analysis of the decision-making process of prehospital emergency providers to perform certain airway interventions.

METHODS

We conducted a scenario-based survey using two sequential video clips of an explosive injury event. The answers were used to conduct descriptive analyses and multivariable logistic regression models to estimate the association between the choice of intervention and training factors.

RESULTS

There were 254 respondents in the survey, 176 (69%) of them were civilians and 78 (31%) were military personnel. Military providers were more likely to complete TCCC certification (odds ratio [OR]: 13.1; confidence interval [CI]: 6.4-26.6; P-value < 0.001). The SC was the most frequently chosen intervention after each clip (29.92% and 22.10%, respectively). TCCC-certified providers were more likely to choose SC after viewing the two clips (OR: 1.9; CI: 1.2-3.2; P-value: 0.009), even after controlling for relevant factors (OR: 2.3; CI: 1.1-4.8; P-value: 0.033).

CONCLUSIONS

Military providers had a greater propensity to be certified in TCCC, which was found to increase their likelihood to choose the SC in early prehospital emergency airway management.

No Benefit in Neurologic Outcomes of Survivors of Out-of-Hospital Cardiac Arrest with Mechanical Compression Device

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) is a major cause of death and morbidity in the United States. Quality cardiopulmonary resuscitation (CPR) has proven to be a key factor in improving survival. The aim of our study was to investigate the outcomes of OHCA when mechanical CPR (LUCAS 2 Chest Compression System™) was utilized compared to conventional CPR. Although controlled trials have not demonstrated a survival benefit to the routine use of mechanical CPR devices, there continues to be an interest for their use in OHCA.

METHODS

We conducted a retrospective observational study of OHCA comparing the outcomes of mechanical and manual chest compressions in a fire department based EMS system serving a population of 1.4 million residents. Mechanical CPR devices were geographically distributed on 11 of 33 paramedic ambulances. Data were collected over a 36-month period and outcomes were dichotomized based on utilization of mechanical CPR. The primary outcome measure was survival to hospital discharge with a cerebral performance category (CPC) score of 1 or 2.

RESULTS

This series had 3,469 OHCA reports, of which 2,999 had outcome data and met the inclusion criteria. Of these 2,236 received only manual CPR and 763 utilized a mechanical CPR device during the resuscitation. Return of spontaneous circulation (ROSC) was attained in 44% (334/763) of the mechanical CPR resuscitations and in 46% (1,020/2,236) of the standard manual CPR resuscitations (p = 0.32). Survival to hospital discharge was observed in 7% (52/763) of the mechanical CPR resuscitations and 9% (191/2,236) of the manual CPR group (p = 0.13). Discharge with a CPC score of 1 or 2 was observed in 4% (29/763) of the mechanical CPR resuscitation group and 6% (129/2,236) of the manual CPR group (p = 0.036).

CONCLUSIONS

In our study, use of the mechanical CPR device was associated with a poor neurologic outcome at hospital discharge. However, this difference was no longer evident after logistic regression adjusting for confounding variables. Resuscitation management following institution of mechanical CPR, specifically medication and airway management, may account for the poor outcome reported. Further investigation of resuscitation management when a mechanical CPR device is utilized is necessary to optimize survival benefit.

Abstract TP385: Evolution of an Organized System of Care Positively Impacts Regional Stroke Treatment

Background: The Southwest Texas Regional Advisory Council (STRAC) Stroke Systems of Care Committee is comprised of hospital, physician and EMS leaders who meet monthly to discuss process improvement and system development with a commitment to improve stroke recognition, response and treatment. Over a seven- year period, this community with a population of 1.5 million people progressed from no organized approach for stroke care to an organized system which includes 12 Primary centers, 2 Comprehensive centers, and over 40 EMS agencies.

Purpose: To evaluate how an organized system has impacted stroke care in Southwest Texas over the past 5 years.

Methods: A retrospective review of Get With The Guidelines®-Stroke data from the STRAC service area was conducted. Specific data points reviewed include diagnosis, mode of arrival, STK 4- IV tPA measure compliance, IV tPA door to needle (D2N) times and discharge disposition.

Results: A total of 20,175 patients were entered between 2010 and 2015 of which 95% (n=19,080) were discharged with stroke diagnosis. Seventy-six percent (n=14,540) of the stroke patients arrived via EMS or walk in. EMS arrivals ranged from 61% (n=1,110) in 2010 to 54% (n=2,015) in 2015. STK 4 measure compliance ranged from 62.8% (n=140) in 2011 to 88.9% (n=158) in 2013. The 2015 STK 4 measure compliance was 84.3% (n=209). IV tPA treatment rates ranged from a low of 9.6% in 2012 to >12% in 2014, 2015 and 2016. D2N < 60 minutes and the percentage of patients discharged home trended upward by over 20% during this period.

Conclusions: Development of an organized system of care has impacted regional stroke treatment as demonstrated by the upward trend and stabilization of compliance of the STK 4 measure, IV tPA treatment rates, and percentage of patients discharged home. Despite improvement there is opportunity to provide community education emphasizing the importance of calling 911 when stroke is suspected. Current performance improvement initiatives include the formation of a regional public education committee and the provision of an annual regional stroke conference. The next focus is to engage area hospitals and EMS in the commitment to advance and improve stroke care.

Paramedics successfully perform humeral EZ-IO intraosseous access in adult out-of-hospital cardiac arrest patients

OBJECTIVE

Studies on humeral placement of the EZ-IO (Vidacare, Shavano Park, TX, USA) have shown mixed results. We performed a study to determine the first-attempt success rate at humeral placement of the EZ-IO by paramedics among prehospital adult cardiac arrest patients.

METHODS

A retrospective cohort analysis of data prospectively collected over a 9-month period. Data are a subset extracted from a prehospital cardiac arrest study. The cohort consisted of adult cardiac arrest patients in whom the EZ-IO placement was attempted in the humerus by paramedics. Choice of vascular access was at the discretion of the paramedic; options included tibial or humeral EZ-IO and intravenous. Primary outcome is the percentage of successful placements (stable, flow, without extravasation) on first attempt. Secondary outcomes are overall successful placement, complications, and reason for failure. Data were collected during a post-cardiac arrest interview.

RESULTS

Humeral intraosseous (IO) access was attempted in 61% (n = 247) of 405 cardiac arrests evaluated with mean age of 63 (±16) years, 58% male. First-attempt successful placement was 91%. Successful placement was 94%, considering the second attempts. In the unsuccessful attempts, 2% reported obesity as the cause, 1% reported stable placement without flow, and 2% reported undocumented causes for failure. There were also 2% reports of successful placement with subsequent dislodgement.

CONCLUSIONS

The results of this study suggest a high degree of paramedic proficiency in establishment of IO access in the proximal humerus of the out-of-hospital cardiac arrest. Few complications suggest that proximal humeral IO access is a reliable method for vascular access in this patient population.

Atrial tracking (synchronous) pacing in a pediatric and young adult population

One hundred pediatric and young adult patients underwent implantation of an atrial tracking pacemaker. Seventy-four pacemakers paced in an atrioventricular (AV) sequential mode at the lower rate limit (DDD) while 26 paced in a ventricular demand mode at the lower rate limit (VDD). Five patients required reoperation during follow-up of 1 month to 2.5 years (mean 1.5 years). Six additional patients required programming to ventricular demand (3) or AV sequential (3) pacing, because of development of sinus bradycardia (2), atrial sensing problems (1) or pacemaker-mediated tachycardia (3). Pulse generators that could sense atrial signals less than 1.0 mV and had a programmable atrial refractory period did not require reprogramming out of the atrial tracking mode. No patient developed atrial flutter or fibrillation. Sensing problems during exercise occurred in 37% of the first 60 pacemakers but in none of the last 40, which had improved electronic components. Atrial tracking pacing is feasible in pediatric and young adult patients.

Long-term follow-up of dysrhythmias following the Mustard procedure

Earlier reports have suggested that the incidence of dysrhythmias after the Mustard procedure can be reduced if the sinoatrial node (SAN) is protected during surgery. To determine if these initial differences continue after longer follow-up, we examined all ECGs available for three groups of patients operated upon from January, 1965, through December, 1977. Group A included 37 patients who survived the operation prior to January, 1972, when surgical modifications were initiated to protect the SAN; group B included 44 patients available for follow-up who were operated upon from 1972 through 1974; and group C consisted of the 39 patients available for follow-up operated upon from 1975 to 1977. Dysrhythmias were classified as passive (failure of initiation or propagation of the SAN impulse), active (atrial flutter or supraventricular tachycardia), or atrioventricular (AV) conduction defects. Results were expressed as the incidence per number of different rhythms during follow-up intervals. The incidence of sinus rhythm in groups B and C (80%) was much greater than in group A (27%) during the first 2 years. However, after 8 years, less than 50% of the rhythms were sinus. Both brady- and tachydysrhythmias were common. Seven patients (6%) required pacemaker insertion for symptomatic sick sinus syndrome. Therefore despite efforts to protect the sinus node, late occurring dysrhythmias remain a significant problem in the postoperative Mustard patient.