UMEM Educational Pearls - EMS

Early defibrillation is a key step in the cardiac arrest chain of survival.  Public Access AEDs may be available more readily than waiting for first responders.  Outside of simple awareness of where AEDs are located, there are newer ways to become aware of public AEDs near a cardiac arrest including cell phone apps or information given by 911.  A British study showed that only 5.9% of AEDs were within 100 meters of the patient and 35% were within 500 meters.  The distance between the AED and arrest may be a barrier for bystander AED use.  This study looked to determine the time required to retrieve an AED and they hypothesized that a distance > 400 meters would be longer than the EMS response times. 

This study used 15 women and 15 men to perform different runs in various environments in different seasons, retrieving AEDs at 200m through 600m and bringing it back to the patient.  In these scenarios, only the 200m distance (400 m round trip) times were deemed to allow enough time to apply and use the AED prior to EMS arrival.  Barriers to AED retrieval included traffic lights, cars, weather and pedestrians.

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In the newly released American Heart Association guidelines on CPR and cardiovascular care, they state there is no evidence that mechanical compression devices show  improvement in survival when compared to manual CPR. They do not recommend routine use of mechanical devices except when high quality CPR can not be maintained or when healthcare personnel safety is impacted such as during transport to the hospital.

Surely there will be more to follow on this topic.

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The authors conducted a pre- and post-implementation study after five North Carolina county EMS agencies switched to single dose epinephrine during out of hospital cardiac arrest treatment from the traditional multidose (every 3-5 minutes) protocol.  They looked at 1 year before and 1 year after implementation. They found no difference in survival to discharge from the hospital in the two groups but there was less return to spontaneous circulation in the single dose group.

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There is no standardized prehospital neonatal resuscitation curriculum for EMS.  The Neonatal Resuscitation Program (NRP) guidelines focus on hospital based births which may not translate to the prehospital environment.

This study was prospective and observational that used a virtual, EMS tailored newborn resuscitation curriculum.  Initially, 350 EMS clinicians watched a 90 min video.  This was then modified based on their feedback to a 60 minute interactive curriculum specifically designed for EMS that emphasized NRP concepts and reinforced how NRP was different from pediatric resuscitation.  17 EMS jurisdictions viewed the program and were then given a brief NRP based quiz before, after and 3 months following the training.  

Feedback was overall positive and post test and 3 month follow up test scores showed improvement from the pre test scores.

Standardized neonatal resuscitation education represents an area where improvements can be made in prehospital education.  This particular curriculum was well received and improved EMS clinicians knowledge based.  Jurisdictional medical directors should work with their department on standardized education for the neonatal population.

Also, stay tuned for updated NRP guidelines which are due to come out this fall.

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Unplanned extubation (UE) occurs in 0-25 % of patients intubated in the prehospital setting and transfer of patient care is one time where UE can occur.  This EMS jurisdiction wanted to improve the rate of communication and confirmation of tube placement at the time of patient transfer.  Over 5 months, the jurisdiction introduced 1) memorandums to paramedics, ED chiefs and respiratory therapist leads, 2) individualized paramedic feedback emails and 3) PCR changes that resulted in documentation of tube placement at transfer of care being a mandatory field. 

Initially the rate of verbal ETT position at transfer of care was 74%.  This increased to > 90% after 8 weeks.  The rate of UE was 2/340 patients.  The implementation of this project showed improvements in perceived accountability, interprofessional relationships and satisfaction with interventions that were noted in the post project focus group.

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This was a multicenter retrospective cohort study over 6 years at 7 level one and two trauma centers.

1631 patients who had out of hospital traumatic cardiac arrest were included. The majority of the patients were adults, female, suffered penetrating trauma (64%) and were in a non-shockable rhythm.  Prehospital epinephrine was given to 54% of patients.

Overall, survival to hospital discharge was lower in the epinephrine group (5% vs 16%).  In the penetrating trauma subgroup, there was no statistically significant survival difference in patients who received epinephrine and those who did not. 

EMS jurisdictions should examine their trauma arrest protocols and consider excluding the use of epinephrine.  Several states, such as Maryland, have already removed epinephrine from the trauma arrest protocol.

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GCS was first introduced in 1974 and now includes a preverbal version for patients < 2 years.

This study looked for non inferiority between motor Glascow Coma Scale (mGCS) and the total GCS in pediatric patients.  The study also examined if a mGCS<6 was non inferior to a GCS < 14 in children.  582 patients < 18 years were reviewed in this retrospective review.

The mGCS  was noninferior to total GCS as a triage tool in pediatric trauma. It also validated the use of mGCS <6 in place of GCS <14 in the field with identification of children at risk of death or requiring ICU care.

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33 paramedics had a short course in thoracic point of care ultrasound.  There was a pre and post test that included the history and physical exam for patient scenarios with COPD and CHF exacerbations.  Paramedics were asked to select the appropriate treatments.  The post test included ultrasound images.  Diagnostic accuracy in the post test improved by 17% and appropriate treatment selection improved by 23%.  Paramedics were also able to correctly identify ultrasound images 90% of the time.

Bottom line: Introducing thoracic ultrasound to paramedics can improve patient care.

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Pulseless electrical activity (PEA) is the initial rhythm in up to 25% of out of hospital cardiac arrests.  

This paper is a systemic review and analysis examining if the rate or width of the initial PEA qrs complex was associated with survival.  The qrs complex was either wide (>= 120 ms) or narrow (<120ms) and a frequency of fast (>= 60/s) or slow (<60/s).  7 studies including 9727 patients were included.  Analysis showed:

- mortality was higher in the wide qrs group compared to narrow

- mortality was higher in the slow PEA rate compared to fast

- neurological outcome was better in patients with a fast PEA rate compared to slow.

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A few states have pediatric out of hospital termination of resuscitation protocols.  This study used CARES data to create a termination protocol that was not only linked to ROSC, but also to neurological outcomes.  This study only included medical arrests.
 

21240 children were included in the study where 2326 patients survived to hospital discharge.  A total of 1894 survived with a favorable neurological outcome.  The criteria developed for pediatric TOR in this study had a specificity of 99.1% and a PPV of 99.8% for patient death.  Another set of criteria had a 99.7% specificity and PPV of 99.9% for predicting death or survival with poor neurological outcome.

TOR criteria of death consisted of:

1. unwitnessed arrest

2. asystole

3. arrest not due to drowning or electrocution

4. no sustained ROSC

TOR criteria of death or survival with poor neurological outcome:

1. unwitnessed arrest

2. asystole

3. arrest not due to drowning or electrocution

4. no sustained ROSC

5. no bystander CPR

Bottom line: Pediatric termination of resuscitation in the out of hospital setting can be appropriate under the right set of conditions.

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Previous studies have suggested that a single dose of epinephrine in out of hospital cardiac arrests compared to multiple dose protocols result in a similar survival to hospital discharge rate.  This study aimed to see if single dose epinephrine compared to multiple doses improved survival in the subset of patients that were 1) in a shockable rhythm or 2) received bystander CPR.

This study looked at patients from 5 EMS systems in North Carolina before and after a protocol change from multiple dose epinephrine to single dose epinephrine in cardiac arrest.  1690 patients were included, 19.2% with a shockable rhythm and 38.9% who received bystander CPR.

The study found:

- Survival to hospital discharge was higher in the single dose epinephrine group who received bystander CPR

- Survival rates were similar in the single and multiple dose epinephrine groups for patients who were initially in shockable rhythms, in asystole/PEA and who did NOT receive bystander CPR.

Bottom Line: More studies are needed to support prehospital protocol changes.

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Previous studies have shown that an on scene time of 10-35 minutes was associated with improved survival in pediatric out of hospital cardiac arrests compared to an on scene time of > 35 minutes.  There was no significant difference in overall survival between < 10 minutes and 10-35 minutes of on scene time.

This study involved a total of 2854 pediatric cardiac arrests in the US and Canada.  The patients who had a cardiac arrest during transport were compared to patients who received on scene CPR by equal minutes.

Among patients < 1 year, intra-arrest transport was associated with lower survival to hospital discharge compared to those that were resuscitated on scene.  There was no association for patients > 1 year.

Bottom line: This study supports resuscitating in place for pediatric cardiac arrests, especially in patients < 1year.

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This was a review of the cardiac arrest registry of Norway between 2016-2021.  The incidence of pediatric out of hospital cardiac arrests was 4.6 per 100,000 child years and significantly higher in children < 1 year (20.9 per 100,000 child years).  There was an overall 18% one year survival rate in the 308 patients included.  

Leading causes of arrests were choking, respiratory disease, drowning and SIDS, making up 67% of cases.

73% of the arrests were initially asystolic and 14% were PEA on EMS arrival.  The presence of shockable rhythms increased with age and VT/VF were the initial rhythm in up to 15% of the 13-17 year age group.  

88% of patients received bystander CPR ( with 68% receiving both chest compressions and ventilations).  A minority of these patients were in a shockable rhythm, but 7 total patients were in refractory VF.  Mechanical CPR devices were used in 35 patients aged 11-17.  ECMO was started in 19 cases.

Bottom line: The rate of bystander CPR in this study was very high and other jurisdictions can attempt to learn from the system in place in Norway to increase their local prehospital interventions.

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Question

EMS may call the hospital to obtain online medical direction when a patient does not wish to come to the hospital.  One difficult task faced by the physician at the hospital is determining the decision making capacity of the patient.  There is currently no nationally recognized standard protocol for physicians providing EMS oversight in this situation.  

The four components involved in the determination of capacity are: understanding, appreciation, reasoning and expression of choice.  This study used a modified Delphi approach with 19 physician experts to develop standardized steps to guide best practices for physicians who are called in real time about a patient refusing EMS transport.  Consensus was defined as 80% agreement.  

The example worksheet with the compilation of recommendations is attached.

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Attachments

• Refusal checklist table-670fb6a9192a8.docx (105 Kb)

Background:
Despite a lack of reliable evidence, sodium bicarbonate (SB) still appears in various protocols as a potential therapy for patients in cardiac arrest. Local EMS protocols also endorse the use of (SB) in specific scenarios such as: tricyclic overdose and hyperkalemia. EMS systems struggle to articulate best practices with respect to indications for SB administration. 

Patients/methods:
Study authors conducted a scoping review of existing literature. The review included in hospital and out of hospital patients with cardiac arrest. Despite multiple studies looking at this question, a total of 12 were included in the final analysis. Criteria for inclusion were as follows: RCT or observational studies looking at patients aged 18 or older who experienced a cardiac arrest. Important outcome metrics incorporated: neurological recovery and survival to discharge. 

Results:
The retrospective review failed to demonstrate a reliable association between survival and administration of sodium bicarbonate. Despite significant limitations (different study populations, retrospective designs), there remains insufficient evidence to consider routine administration of bicarb in the setting of cardiac arrest. 

Bottom line:
Empiric administration of SB is not linked to a reliable benefit. SB may be considered for specific indications (tricyclic overdose, hyperkalemia) but is unlikely to improve outcomes such as neurologic recovery or hospital discharge. EMS systems should avoid recommending routine SB administration for patients with out of hospital cardiac arrest.

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This study looks at the efficacy of ketamine vs. midazolam for the prehospital sedation of acutely agitated patients, examining the need for repeat sedation (by EMS or in the ED), adverse events and length of stay.

A greater number of patients required repeat sedation within 90 minutes with initial ketamine dosing compared to midazolam. There was no difference in patients receiving repeat sedation within 20 minutes between the two groups.

There were no significant differences in time to repeat sedation, total sedation doses (by EMS or in the ED), use of bag valve mask ventilation or intubation, use of physical restraints, admission location/level of care, or length of stay in the Emergency Department (ED), hospital, or Intensive Care Unit.

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BACKGROUND:
Cardiac arrest is time sensitive disease. Despite significant advances in resuscitation technology such as eCPR and mechanical compression devices, early basic life support interventions (specifically bystander CPR) are strongly associated with survival. EMS systems must advocate for early initiation of bystander CPR. Dispatch Assisted CPR (DA-CPR) is one of several strategies designed to improve outcomes and encourage early compressions. To optimize survival, EMS systems should achieve a comprehensive understanding about barriers to succesful initiation of DA-CPR. 

METHODS AND OUTCOMES:
49,165 patients with out of hospital cardiac arrest were eligible for inclusion the study, and over 36,000 underwent successful DA-CPR. The study's primary outcome was good neurological recovery at hospital discharge. Secondary outcomes included: prehospital return of spontaneous circulation (ROSC)and survival to hospital discharge. The authors defined successful DA-CPR when bystanders initiated compressions and continued resuscitation until the arrival of EMS. 

RESULTS:
Quite a few results were consistent with prior studies. Unsuccessful DA-CPR was associated with: 

• Advanced patient age (>65 yo) 
• Arrest location in private or non metropolitan place
• Lack of recognition of cardiac arrest 
• Lack of bystander education on cardiopulmonary resuscitation

Successful DA-CPR was more likely associated with the presence of family members at the scene and improved neurological recovery. Witnessed arrests were also more likely to receive successful DA-CPR. Not surpringly, patients in the successful DA-CPR group also exhibited improved survival to discharge and prehospital ROSC. 

BOTTOM LINE:
Though the study is retrospective and involves a host of confounding variables, EMS systems continue to identify modifiable factors linked to the delivery of DA-CPR. Improved community CPR education and dispatcher training may contribute to higher DA-CPR rates. 

BALTIMORE, MD,  SPECIFIC PEARL:
Baltimore metropolitan jurisdictions are collaborating with the CPR LifeLinks program to address DA-CPR. The CPR LifeLinks program a national initiative “to help communities save more lives through implementation of telecommunicator and high performance CPR programs."  https://www.911.gov/projects/cpr-lifelinks/

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Several studies have shown that patients who require a resuscitative thoracotomy (RT)  have a higher odds of survival if they are transported by police or in private vehicles.  This study examined 195 patients who required RT to see if prehospital intubation and out of hospital time (OOHT) affected ROSC rates.

There was no association between OOHT and ROSC and no association of OOHT and survival.  The mean OOHT for this study was only 25 minutes which is faster than other studies.  

The odds of ROSC were lower in patients who had ANY intubation attempts prior to arrival.

Bottom line: BLS airway management (or supraglottic placement) may be more beneficial for the trauma arrest patient in the prehospital setting.

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Maternal morbidity continues to increase in the US with a mortality rate in 2021 of 39.2 deaths/100,000 live births.  There has been an intense focus on training and quality improvement within hospitals, but not much has changed in the prehospital education arena.  This study aimed to quantify the complications encountered by EMS clinicians.  

In the 2018-2019 EMS dataset used, there were a total of 56,735,977 EMS activations which included 8641 out of hospital deliveries, 1712 documented delivery complications and 5749 records of newborns.

1% of the out of hospital deliveries had a documented complication for the mother.  Of these complications, 94% were for hemorrhage, 6% for abnormal presentation, 0.2% for shoulder dystocia, and 0.4% for nuchal cord.  

Few patients had medications given, including 0.4% receiving oxytocin.  no patients received prehospital blood transfusion or TXA.  Of note, in the years since this data was obtained, TXA and whole blood have started to appear on more medic units, but it is still not necessarily commonplace.

Bottom line: While still rare, prehospital delivery does occur and EMS should be prepared for any possible complications.  Medical directors should look at their jurisdictional/state protocols to see if oxytocin/TXA or whole blood should be included (if not already available).  EMS clinicians should be educated on up to date management of OB emergencies.

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The short answer is yes, pediatric trauma patients without blood pressures recorded from EMS had a higher mortality (4.3%) compared to pediatric patients that did have a recorded blood pressure (1.1%). This is based off of a prehospital study conducted in Japan.

Prehospital vital signs are left out more often in pediatric patients compared to adults. Of those vital signs that are recorded, blood pressure is the most common one left off.

There can be several barriers to obtaining a blood pressure on the pediatric patient in the prehospital setting: lack of properly sized equipment, an uncooperative child, and lack of education. However, the inability to obtain a blood pressure can also be due to the patient being more severely injured and having other skills performed or was unable to be obtained due to poor perfusion. In this study, those who did not have a recorded blood pressure also had a lower GCS score and a higher injury severity score.

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