CPR Devices

[EMT19053]

The ambulance service that I vol. with is looking into getting a Zoll Auto Pulse. The sales rep came out and did a demo on Annie and threw his sales pitch. It all looked and sounded pretty good but I thought I would ask for opinions from all of you that use the device in the field. Does it have any limitations in the field? Has it improved your save rate? Thank you all for your input.

 

[skyemt]

just so you know, there are opinions out there that question if there is any benefit at all.

you can look up articles by Dr. Bryan Bledsoe and others, detailing the ineffectiveness of the devices.

nothing beats good CPR.

of course, there are differing opinions, and i have not personally used the device.

perhaps some out here have, but i certainly would NOT take the word of a salesman.

 

[EMT19053]

Yeah, I know. I trust a salesman about as far as I can throw them. This is why I posted the question here to ask those that have used it or seen it used. The reason we are looking into the device is because CPR is difficult and dangerous in the back of a moving ambulance or while "riding the cot". Another question is does the device provide more adequate perfusion than a person trying to do CPR while bouncing around in the back of a moving rig. Bob Page said at convention that CPR is only 20% effective in the back of a moving rig. If it does than why not use the device and protect yourself from possible injury. Just another topic that could be argued for days I guess. Thanks for the reply skyemt.

 

[uscgk9]

your company should weigh the cost of the equipment verses the cost of other equipment you may need. You should also look at how many time you actually do CPR in the back of the truck. My squad runs over 3,000 calls a year and I think we have run about 3 codes. If your area is large your company might better itself with something like a GPS system to we can these locations quicker. What does this thing cost anyway???/

 

[Arkymedic]

your company should weigh the cost of the equipment verses the cost of other equipment you may need. You should also look at how many time you actually do CPR in the back of the truck. My squad runs over 3,000 calls a year and I think we have run about 3 codes. If your area is large your company might better itself with something like a GPS system to we can these locations quicker. What does this thing cost anyway???/

Consider yourself lucky. We run at least 3 a week.

 

[uscgk9]

well that should keep you busy. I seem to get stuck with tooth aches and back pain....lol.

 

[Ridryder911]

We average about 20% of our 11k calls are arrest as well.

R/r 911

 

[MMiz]

Our county determined that CPR in a moving ambulance, with any device, was ineffective. They implemented a new procedure of working CPR patients in the field for 30 minutes with a ResQ pod and pump.

The Zoll AutoPulse looks like a cool toy, but everything I've read tells me that patient outcome hasn't been impacted by using the AutoPulse.

 

[EMT19053]

your company should weigh the cost of the equipment verses the cost of other equipment you may need. You should also look at how many time you actually do CPR in the back of the truck. My squad runs over 3,000 calls a year and I think we have run about 3 codes. If your area is large your company might better itself with something like a GPS system to we can these locations quicker. What does this thing cost anyway???/

Our area is very rural with only about 250 calls a year. The last year we have had about 6 codes. We use GPS on our cell phones but the problem is that our rural 911 addresses have not been mapped yet therefore GPS does not recognize the addresses. The Zoll Auto-Pulse costs about $15,000. I think it is alot of money but if it saved one life I suppose it would be justified. The president of the service is applying for an AFG grant and our cost share would be 5%. Because we are rural with sometimes long transport times is why the service is wanting to purchase the device. I am still a little bit unsure of it which is why I am seeking everyones opinions. Thanks for the replies everybody.:unsure:

 

[Markhk]

Hrm...I think you need to also look at the battery life (about 30 minutes) of the Autopulse if you have extended transport times, the reason being you might have to buy and stock on your rigs more batteries than other crews might have to.

 

[el Murpharino]

Here's a dissenting article from a NY times article in 2006:

"A randomized trial of an automated cardiopulmonary resuscitation machine approved by the Food and Drug Administration suggests that it produces worse outcomes than CPR performed manually."

"The results with the machine were so poor that the study, originally planned for 12 to 18 months, was halted after 9 months."

Here's the full article: http://www.nytimes.com/2006/06/27/health/27tech.html?_r=1&oref=slogin

 

[JPINFV]

Parts removed due to character constraints.

JAMA: The Journal of the American Medical Association
Manual Chest Compression vs Use of an Automated Chest Compression Device During
Resuscitation Following Out-of-Hospital Cardiac Arrest: A Randomized Trial
ISSN: 0098-7484Accession: 00005407-200606140-00027Full Text (PDF) 144 K
Author(s):

Hallstrom, Al PhD; Rea, Thomas D. MD, MPH; Sayre, Michael R. MD; Christenson,
James MD; Anton, Andy R. MD; Mosesso, Vince N. Jr MD; Van Ottingham, Lois BSN;
Olsufka, Michele RN; Pennington, Sarah RN; White, Lynn J. MS; Yahn, Stephen
EMT-P; Husar, James EMT-P; Morris, Mary F.; Cobb, Leonard A. MD

Issue:Volume 295(22), 14 June 2006, p 2620-2628


Abstract

Context: High-quality cardiopulmonary resuscitation (CPR) may improve both
cardiac and brain resuscitation following cardiac arrest. Compared with manual
chest compression, an automated load-distributing band (LDB) chest compression
device produces greater blood flow to vital organs and may improve resuscitation
outcomes.

Objective: To compare resuscitation outcomes following out-of-hospital cardiac
arrest when an automated LDB-CPR device was added to standard emergency medical
services (EMS) care with manual CPR.

Design, Setting, and Patients: Multicenter, randomized trial of patients
experiencing out-of-hospital cardiac arrest in the United States and Canada. The
a priori primary population was patients with cardiac arrest that was presumed
to be of cardiac origin and that had occurred prior to the arrival of EMS
personnel. Initial study enrollment varied by site, ranging from late July to
mid November 2004; all sites halted study enrollment on March 31, 2005.

: Standard EMS care for cardiac arrest with an LDB-CPR device (n = 554) or
manual CPR (n = 517).

Main Outcome Measures: The primary end point was survival to 4 hours after the
911 call. Secondary end points were survival to hospital discharge and
neurological status among survivors.

: Following the first planned interim monitoring conducted by an independent
data and safety monitoring board, study enrollment was terminated. No difference
existed in the primary end point of survival to 4 hours between the manual CPR
group and the LDB-CPR group overall (N = 1071; 29.5% vs 28.5%; P = .74) or among
the primary study population (n = 767; 24.7% vs 26.4%, respectively; P = .62).
However, among the primary population, survival to hospital discharge was 9.9%
in the manual CPR group and 5.8% in the LDB-CPR group (P = .06, adjusted for
covariates and clustering). A cerebral performance category of 1 or 2 at
hospital discharge was recorded in 7.5% of patients in the manual CPR group and
in 3.1% of the LDB-CPR group (P = .006).

Conclusions: Use of an automated LDB-CPR device as implemented in this study was
associated with worse neurological outcomes and a trend toward worse survival
than manual CPR. Device design or implementation strategies require further
evaluation.

Trial Registration: clinicaltrials.gov Identifier: NCT00120965

----------------------------------------------


METHODS

Study Design

[parts removed]

Population

Adults with out-of-hospital cardiac arrest who received attempted resuscitation
by a participating EMS agency were enrolled unless an exclusion criterion was
present (Figure). Patients treated by EMS subsequently determined to meet
exclusion criteria were excluded from the analysis.


A primary comparison population, patients who were in cardiac arrest at the time
of EMS arrival and whose cardiac arrest was considered to be of cardiac origin,
was chosen a priori as the population most likely to benefit from chest
compressions. Cardiac etiology was determined by the site study coordinator or
investigator based on the EMS report forms and hospital records. Early in the
enrollment, study adherence (application of the LDB-CPR device based on
out-of-hospital report) was very low at site D when the advanced life support
unit arrived before the study unit. Arrival of an advanced life support unit 90
seconds or longer before the study unit was added as a site-specific exclusion
from the primary comparison population.

Study Protocol and Intervention

[removed, description of the device]

During a run-in period ranging from 0.7 to 2.8 months, EMS personnel integrated
the automated device into out-of-hospital care. Initial training of EMS
personnel included hands-on skill practice using the device with a mannequin and
a video presentation with rationale for the LDB-CPR device. Refresher training
was not specified by design to best replicate real-world conditions and was
highly variable during the study.

The protocol allowed 3 options for the resuscitation intervention. Initially all
sites chose option 1, a "quick look

Option 2 was immediate CPR with manual compressions regardless of randomization
until the first shock assessment. Site C, the only EMS with a comprehensive
quality-improvement effort to reduce pauses in chest compressions, changed its
resuscitation intervention to option two 110 days after starting the study. The
change was implemented after quality-improvement review identified prolonged
time without compressions while deploying the LDB-CPR device.

Option 3 allowed analysis, and shock if appropriate, before beginning CPR. In
all cases, after rhythm assessment and shock if indicated, additional necessary
compressions were to be performed manually or with the LDB-CPR device according
to randomization. In all other aspects, sites followed their standard resuscitation
protocol until the patient was declared dead or regained stable spontaneous
circulation and was transported to and arrived at the emergency department.

End Points

The primary end point was defined as survival with spontaneous circulation 4
hours after the 911 call. This measure avoids inherent inconsistencies in
site-to-site variations in the definition of "admittance to the hospital."
Secondary end points included discharge from the hospital and cerebral
performance category score at discharge from the hospital that was obtained from
the hospital records. 21

Data Collection

Data were collected from EMS reports, defibrillator recordings, a study
questionnaire, and hospital records.[removed further description]

Sample Size

[removed]

Statistical Analysis

Comparisons were made by intention-to-treat assignment. Logistic regression was
applied using generalized linear mixed models with the robust sandwich estimator
of the variance to compare the outcome of individual episodes between the 2
study groups. 27-30 Models were adjusted for covariates previously demonstrated
to predict survival 31,32 as well as cluster (a source of nonindependence).

A single a priori subgroup analysis of the primary population was specified
based on initial rhythm (asystole, ventricular fibrillation/ventricular
tachycardia, pulseless electrical activity). In 6.1% (47/767) of participants,
electrocardiographic rhythm was not available and the automated external
defibrillator did not advise to shock. These were assumed to be asystole or
pulseless electrical activity. Three of the 47 cases were assigned the rhythm
observed at the next electrocardiographic analysis. In the remaining 44 cases,
the initial rhythm was imputed based on factors that discriminated significantly
between patients with initial rhythm of pulseless electrical activity and
asystole.

Post hoc subgroup analyses evaluated whether the intervention effect differed by
site or by the time since the site began enrolling patients. Interactions were
tested using an interaction term between treatment group and the covariate of
interest.

Analyses were conducted using SPSS version 12.0 (SPSS, Chicago, Ill) and R
version 2.3 (R Foundation for Statistical Computing) statistical software.
Unless explicitly stated, P values are unadjusted for covariates or clustering.
For the primary and secondary end points, P values were generally adjusted; by
protocol, the [alpha] level for the primary end point was set at .05.

RESULTS [parts selectivly removed]

The data and safety monitoring board met on March 11, 2005, and again on March
28, 2005, to review the results for 757 patients enrolled through January 31,
2005, and recommended suspension of enrollment until data for the 314 patients
enrolled during February and March could be evaluated. Results prompted
additional data collection, including estimates of chest compression duration in
the first 5 minutes of the resuscitation effort, drugs administered prior to the
patient arriving at the hospital, mode of in-hospital death, and other details
indicating lung, heart, or cerebral damage. On June 27, 2005, the steering
committee reviewed these expanded data and recommended that the trial be halted.

 

[JPINFV]

There were a total of 1377
episodes, of which 373 in the manual CPR group and 394 in the LDB-CPR group were
eligible for study enrollment (Figure).

Demographic features, cardiac arrest circumstances, and treatment characteristics
were generally similar between the treatment groups. Among primary cases,
patients in the LDB-CPR group were more likely to receive epinephrine (P = .03)
and have longer time intervals to first shock (for patients found in ventricular
fibrillation/ventricular tachycardia) (P = .001), termination of resuscitative
effort (P = .01), and hospital transport (P = .01) (Table 2). In the LDB-CPR
group, the device was applied during the resuscitation to 83.8% of the primary
cases, 73.5% of noncardiac cause cases, and 52.5% of cases for which cardiac
arrest occurred after EMS arrival. Among primary study patients, the mean (SD)
time from 911 call to first use of the LDB-CPR device was 11.9 (4.5) minutes
with a median of 10.9 minutes.



There was no significant difference in survival at 4 hours after the 911 call
between the manual CPR group and the automated LDB-CPR group overall (N = 1071;
29.5% vs 28.5%; P = .74) or among the primary study population (n = 767; 24.7%
vs 26.4%; P = .62). Survival to hospital discharge was lower in the LDB-CPR
group among primary episodes (5.8% vs 9.9% [P = .04]; adjusted for covariates
and clustering, P = .06), but similar among the nonprimary cases (10.6% vs
11.9%; P = .72). Excluding 5 survivors with incomplete neurological data,
survival with a cerebral performance category score of 1 or 2 was recorded in
7.5% (28/371) of patients in the manual CPR group compared with 3.1% (12/391) in
the LDB-CPR group (P = .006).

The survival effect of the LDB-CPR device differed, but not significantly (P =
.37), according to initial rhythm of ventricular fibrillation, pulseless
electrical activity, or asystole. In contrast to the ventricular fibrillation
and pulseless electrical activity subgroups, outcomes trended better in the
LDB-CPR group in the asystole subgroup for 4-hour survival (17.2% vs 10.4%) and
hospital discharge (1.7% vs 0.6%) (Table 3).



[no difference between sites and the hospital for patients who normally wouldn't make it anyways]


As expected from historical rates, survival was significantly better in site C
compared with other sites (Table 4 and Table 5). However, the association
between survival and treatment group did not differ significantly at site C
compared with the other sites (P = .12 for interaction, adjusted for other
covariates and clustering; Table 4). Both before and after the December 28
protocol change, EMS personnel at site C had higher protocol compliance and used
the LDB-CPR device earlier in the resuscitative effort than EMS personnel at the
other sites (Table 5).

[shorter response times had better results]

Mode of death in the hospital was similar between the treatment groups.
Approximately 35% died within 48 hours from a presumed cardiac cause.


COMMENT

In this trial comparing manual CPR with automated LDB-CPR, interim results
prompted early termination as recommended by the data and safety monitoring
board. Although 4-hour survival was similar between treatment groups among
primary cardiac arrest episodes, hospital discharge survival was lower in the
LDB-CPR group (5.8% vs 9.9%) as was survival with intact neurological status.

Evidence indicates that increased blood flow during CPR should translate to a
higher likelihood of successful resuscitation. 2 The LDB-CPR device evaluated in
this study produces greater circulation than manual CPR in animal models of
cardiac arrest. 16,17 In observational human studies of the device, most but not
all investigators have indicated greater likelihood of return of spontaneous
circulation compared with historical controls, with 1 study demonstrating better
survival to hospital discharge. 24,33,34 The results of the current randomized
study were not expected and there is no obvious explanation.

One potential explanation is that patients in the manual CPR group benefitted
from a Hawthorne effect such that manual CPR quality initially exceeded standard
practice. 35 Conversely, there could have been a "learning curve" for use of the
device with performance expected to improve over time. However, during the last
2 months, survival to hospital discharge for primary cases was 8.1% for manual
CPR and 5.0% for LDB-CPR, findings similar to those from the initial months of
the study (11.7% and 8.0%, respectively).

Another possible explanation for the outcomes is that deployment time for the
LDB-CPR device was prolonged. Mean time to first shock in primary cases with
initial rhythm of ventricular fibrillation occurred 2.1 minutes later in the
LDB-CPR group. While device deployment time was not measured directly, site C
applied the device earlier and more frequently than the other sites and yet
showed greater relative hazard for the intervention (Table 5).

Another implementation-based explanation is enrollment bias. Enthusiasm for the
automated LDB-CPR device could have motivated EMS personnel to enroll patients
who usually would have been declared dead on arrival. This may have occurred in
a few cases because 21 more primary patients were enrolled in the LDB-CPR group
compared with the manual CPR group. However, almost all long-term survivors were
among patients whose initial rhythm was ventricular fibrillation, pulseless
ventricular tachycardia, or pulseless electrical activity, and for whom
enrollment and baseline characteristics were comparable between the 2 study
groups. Moreover, the adverse intervention relationship was seen among patients
presenting with ventricular fibrillation, a group that would routinely receive
resuscitation and for whom enrollment bias was unlikely.

Other potential explanations for our findings may be related to the direct
physiological effects of the automated device. Medications administered with
superior blood flow generated by the device might exceed therapeutic thresholds
and instead be toxic. However, we are unaware of evidence for such an effect. An
additional consideration involves the manner in which blood flow is generated
(ie, 80 compressions/min with the LDB-CPR device vs manual CPR rates of >=100
compressions/min). There may be an as-yet unmapped relationship between time,
flow, and reperfusion injury when early low blood flow may generate less
reperfusion injury. 36,37 There is also the possibility that chest compressions
by the LDB-CPR device may cause direct physical damage to the cardiopulmonary
system, although review of hospital records to monitor for adverse events did
not overtly identify this possibility. 38

In addition, there is a 1 in 40 chance that the adverse survival outcome could
have occurred under the null hypothesis of no treatment effect. In this regard,
the possibility of unequal risk in the groups randomized at site C should be
considered. That site accounted for 40% of the survivors, and survival in its
manual CPR group was substantially greater than in previous years.

The effect of LDB-CPR compression may have differed depending on the presenting
rhythm or time from collapse to resuscitation effort. Patients with asystole,
potentially most consistent with untreated and longer arrest duration, appeared
to benefit from the LDB-CPR compression whereas those with ventricular
fibrillation or pulseless electrical activity appeared to experience harm. In a
post hoc multivariable analysis of witnessed primary cases found in ventricular
fibrillation or pulseless electrical activity, shorter response times favored
the manual CPR group, while the model indicated the treatment groups would have
the same survival when the response time reached 6.6 minutes (P = .06 for
interaction). To some extent, this finding may be interpreted as consistent with
other reports of observational human studies that have evaluated this LDB-CPR
device. 24 These relationships and their underlying mechanisms require
additional investigation.

Just as poor adherence dilutes the observed effect of a beneficial treatment, it
also dilutes the effect of a harmful treatment. Thus, the observed differences
between site C and the other sites are compatible with the overall impression
that this implementation of mechanical CPR with the LDB-CPR device may be
harmful. The differences are also compatible with the concept that the magnitude
of harm may depend on the capabilities of the EMS system.

This study has several limitations. The LDB-CPR device was implemented at
various stages of resuscitation, a flexibility designed to minimize CPR
interruptions. A protocol requiring device implementation at a particular point
of care might produce different results. For example, device application in
apparently late stages of arrest (the asystole subgroup) appeared to be modestly
beneficial. Although each site conducted a run-in phase with the device, more
intensive training or a longer run-in phase may have produced different results.
The study evaluated the proportion of time with CPR during the first 5 minutes
of EMS resuscitation, but did not evaluate the "quality" of manual CPR (ie,
rate, depth, recoil) or how manual and LDB-CPR compression differed later in the
course of resuscitation. Because of adverse trends in safety outcomes, the study
was terminated prior to complete enrollment. Although stopping the study for
statistical futility was not part of the prespecified monitoring plan, the
conditional power to detect the hypothesized difference in the primary outcome
was only 0.55 at the time of study termination.

 

[JPINFV]

CONCLUSION

As implemented in this study, the use of an automated LDB-CPR device for
resuscitation from out-of-hospital cardiac arrest appeared to result in lower
survival and worse neurological outcomes than traditional manual CPR. Device
design and implementation strategies may need further preclinical evaluation.

The results of this study underscore the complexity of resuscitation from
out-of-hospital cardiac arrest. Further research is required to understand the
interaction of manual or assisted chest compressions with other aspects of
resuscitation such as the phase of the arrest, 39 drug choice and dose, timing
of defibrillation, and treatments such as hypothermia and coronary reperfusion.

 

[skyemt]

as i stated earlier,

NOTHING beats good, quality manual CPR.

if you get proficient at that, there is no need for expensive "toys" that do not improve patient outcomes.

 

[JPINFV]

Playing devils advocate here, are we and should we be willing to use a device that decreases outcomes in order to approve crew safety (assuming all/most cardiac arrest patients are transported instead of being worked and called in the field)? [CPR can not be preformed adequately while seatbelted.]

What about frontier/rural areas with limited amount of providers? [2 man crew transporting an arrest]

 

[skyemt]

my agency is in a rural area...

i would not feel too good about putting a device on a patient that i knew reduced his chances of survival, while i sat safely belted in my seat...

where would you draw the line?

what about ALS procedures that required them being "unbelted"...
what would you say about that?

perhaps the ambulances should take safer back roads at slower speeds, rather than the fastest way to the hospital... it would also reduce the patient outcome, but improve crew safety...

once you go down that road, it is difficult to turn back.

besides, from what i understand, you do not just set the device and leave it alone for the duration... it needs adjusting, monitoring to assure correct placement, compression depth, etc...

 

[JPINFV]

Well, the studies about emergency transport [lights and sirens] generally don't support their use [time saved being not clinically significant, even if it is statistically significant].

As far as procedures, a fair amount can be done seatbelted [drug administration, ventilating a patient with an advanced airway, defibrillation/cardioversions with patches instead of paddles, taking vital signs]. My life is, simply put, worth more to me than my patient's life. Yes, a certain amount of risk is understood to be taken, especially if transporting emergently, but such risks should be minimized as much as possible. Of course, none of this changes the fact that EMS's track record for saving unwitnessed cardiac arrests are rather poor to begin with [EMS saves lives by preventing arrest, but that's for a different thread completely].

 

[skyemt]

i understand devils advocate, but....

what's your point...

ok, so we shouldn't use lights, sirens... don't do anything if you're not belted in... it doesn't matter anyway because we can't revive anyone...

you might as well go back to the old days of the caddy ambulances...load your patient, strap yourself in, and take a ride to the hospital.

just think about it... if you were the patient, which you may be one day, how would you want the treatment to be?

i understand that our life is valuable.. but providing patient care in the back of a moving rig comes with an inherent risk... which you accepted..

if you are not longer willing to accept the risk, perhaps....

 

[JPINFV]

it doesn't matter anyway because we can't revive anyone...

you might as well go back to the old days of the caddy ambulances...load your patient, strap yourself in, and take a ride to the hospital.

I think you missed the part where I said EMS is best at preventing arrests and not raising people from the dead. Providing prehospital care in a manner that prevents people from dieing in the first place is not the same as throwing up our collective hands and going back to drive real fast to the hospital.

just think about it... if you were the patient, which you may be one day, how would you want the treatment to be?

I won't expect someone to sacrifice life or limb for an improbable outcome. As far as I'm concerned, when I have a cardiac arrest, I'd rather be worked in the field and declared in the field than have a mad rush to the hospital for little/no gain and big risk to the transporting crew.

i understand that our life is valuable.. but providing patient care in the back of a moving rig comes with an inherent risk... which you accepted..

if you are not longer willing to accept the risk, perhaps....

And that is why we, as a profession, should move towards developing safer methods and safer equipment. Providing care in the back, in large part, is as risky as people want to make it. How many providers sit in the back unseatbelted and do nothing besides take vital signs? Yes, there is an inherent risk, heck, there's an inherent risk just driving to work, but that does not mean that we should do what we can to minimize that risk. If people threw up their hands at every safety problem there wouldn't be things like enginered sharp protection.