a b s t r a c t

Background: The management of cardiac arrest patients receiving cardiopulmonary resuscitation (CPR) is an es- sential aspect of emergency medicine (EM) training. At our institution, we have a 1-month Resuscitation Rotation designed to augment resident training in managing critical patients. The objective of this study is to compare 30- day mortality between cardiac arrest patients with resuscitation resident (RR) involvement versus patients with- out. Our secondary outcome is to determine if RR involvement altered rates of initiating Targeted temperature management (TTM).

Methods: This study was conducted at a single site tertiary care Level-1 trauma center with an Emergency Depart- ment (ED) census of nearly 130,000 visits per year. Data was collected from 01/01/2015 to 01/01/2018 using electronic medical records via query. Patients admitted with cardiac arrest were separated into two groups, one with RR involvement and one without. Initial rhythm of ventricular fibrillation/tachycardia (VFIB/VTACH), 30-day mortality, history of coronary artery disease (CAD), and initiation of TTM were compared. Statistical anal- ysis was performed.

Results: Out of 885 patient encounters, 91 (10.28%) had RR participation. There was no statistical difference in 30- day mortality between patients with RR involvement compared to those without (71.42% vs 66.36%; P = 0.3613). However, TTM was initiated more in the RR group (20.70% vs 8.86%; P = 0.0025). Patients who received TTM also had a lower 30-day mortality compared to those without TTM (52.94% vs 70.87%; P = 0.0020). Patients who were older and had no history of CAD were also noted to have a statistically significant higher 30-day mortality. All other variables were not statistically significant.

Conclusion: Resuscitation resident involvement with the care of cardiac arrest patients had no impact in 30-day mortality. However, the involvement of RR was associated with a statistically significant increase in the initiation of TTM. One limitation is that RR participated in 10.28% of the cases analyzed herein, thus the two arms are un- balanced in size. Future work may investigate if the increase in TTM in the RR involved cases may portend im- proved rates of Neurologically intact survival or more rapid achievement of goal temperatures.

(C) 2020

1. Introduction

The resuscitation of cardiac arrest patients via cardiopulmonary re- suscitation (CPR) is an essential aspect of emergency medicine (EM) training. There are over 300,000 annual cases of cardiac arrest in the adult population in the United States [1]. Although there have been nu- merous advances in emergency and post resuscitation care, the survival

* Corresponding author at: Oakland University William Beaumont School of Medicine, 586 Pioneer Dr., Rochester, MI 48309, USA.

E-mail address: [email protected] (D.M. Lee).

to hospital discharge rate for cardiac arrest still remains merely at 5% to 15% [2]. Given the low rates of survivability, there is a significant need for improvement in the Treatment protocols of cardiac arrest patients.

One important therapy in post resuscitation care for cardiac arrest patients is targeted temperature management , which involves the cooling and maintenance of the core body temperature of a cardiac arrest patient. It is postulated that cooling may reduce cerebral oxygen demand, which lowers the number of harmful reactions that can lead to neurological damage (i.e. free radical production and apoptosis). These reactions occur rapidly, often within 2-4 min, thereby the provi- sion of TTM is an integral component of post-arrest management. TTM

https://doi.org/10.1016/j.ajem.2020.12.021

0735-6757/(C) 2020

has been shown to improve neurological outcome and recovery of pa- tients after a return of spontaneous circulation (ROSC) [3,4]. With a sig- nificant number of patients experiencing poor neurological outcome after cardiac arrest, it is imperative to study the application of TTM [5]. Improving outcomes in this patient population has proved to be challenging, given the high morbidity and mortality associated with car- diac arrest [6]. A potential improvement to consider is having additional staff dedicated to the treatment of resuscitation patients. At our institu- tion, we developed a unique 1-month curriculum called the Resuscita- tion Rotation that was specifically designed and implemented to augment resident training in managing critically ill patients. During this rotation, an EM resident would be devoted to active management of high acuity clinical resuscitations. Previous literature has shown the educational benefits of a focused curriculum such as ours, including Mahler’s research demonstrating the benefits of a dedicated ultrasound rotation and Jones’s description on the benefits of a focused transtho- racic echocardiography course [7,8]. We predicted that our newly de- signed Resuscitation Rotation would have a similar clinical impact. While the initial goal of this rotation was to provide additional educa- tional exposure to resuscitation, we theorize that resuscitation resident (RR) involvement should also facilitate the care of the critically ill and therefore, lead to improved patient outcomes. The objective of this study is to measure the impact of RR involvement on the care of cardiac arrest patients. More specifically, our primary objective will be compar- ing 30-day mortality between cardiac arrest patients with RR involve- ment versus patients without. Our secondary objective will be to

assess if RR involvement alters the rate of initiating TTM.

1. Methods

The methods utilized for this study were performed according to those used in Burla et al. with minor modifications [9].

• 1. Overview

This was a retrospective study conducted in a single site tertiary care Level-1 trauma center with an emergency department (ED) census of nearly 130,000 visits per year.

• 1. Course description

On September 2014, our institution began a novel 1-month rotation for their ED residency program. The rotation is part of the post-graduate year 2 (PGY-2) curriculum and focuses on facilitating the overall care of High acuity patients.

The main targets of the high acuity patient population include car- diac arrest, sepsis, pulmonary embolism, cerebrovascular emergencies, trauma, and other acutely ill patients. During the rotation, residents spend over 40 h a week in the ED during peak hours with high acuity pa-

data were exacted by an experienced data user, and relevant clinical in- formation was organized into a database [9].

• 1. Study population criteria

There were a total of 885 patient encounters observed. Inclusion criteria for our patient population included patients over the age of 18, admitted to our institution for cardiac arrest, and clinical presence or ab- sence of the RR. Exclusion criteria included pediatric and pregnant pop- ulations, patients who expired in the ED, and patients who were admitted without ED involvement (i.e. direct admissions). Patients ad- mitted with cardiac arrest were included and separated into two groups, one with RR involvement and one without. Age, sex, initial rhythm of ventricular fibrillation/tachycardia, history of coronary artery disease (CAD), 30-day mortality and initiation of TTM were compared.

• 1. Outcome measures

The primary outcome of this study was to compare 30-day mortality between patients who received RR care and those who did not. Our sec- ondary outcome was to measure the provision of TTM, in cases with and without a RR.

• 1. Data analysis

Several variables were compared between patients with and with- out RR. Both univariate and multivariate analyses were performed to adjust for confounding variables. Two-Sample independent T-Tests and Chi-Square tests were used to compare continuous and categorical variables, respectively. Logistic regression was used to evaluate our Multivariate statistical analysis. A P value of <0.05 was considered sta- tistically significant. All analyses were performed using SAS 9.4 (SAS In- stitute Inc., Cary, NC, USA) [9].

1. Results

Our EMR query yielded a total of 885 patient encounters admitted with cardiac arrest. Ninety-one of these cases involved RR participation (10.28%). Baseline demographics between patient populations were not statistically significant and are illustrated in Table 1.

A multivariate analysis was conducted to measure the effect of RR on

30-day mortality, which is depicted in Table 2. There was no statistical difference found in 30-day mortality between patients with RR involve- ment compared to those without. Specifically, 71.42% of patients who

Table 1

Baseline demographic variables of patients with resuscitation resident involvement and patients without.

tients. Residents are expected to document all of their hours, encoun- ters, and procedures during the entirety of their rotation [9].

Patient age in years

RR

involvement (n = 91)

No RR

involvement (n = 794)

P-value

2.3. Design

Mean Age (Standard Deviation) 66.49 (16.59) 67.93 (17.47) 0.4571 Patient body mass index (BMI)

After approval by institutions Institutional Review Board (IRB) ap- proval, data were collected from 01/01/2015 to 01/01/2018 using elec-

Mean BMI (Standard Deviation)

Biological sex of patient

30.69 (7.55) 29.21 (8.56) 0.1986

tronic medical record via a query of Epic (Epic Systems Corp.; Verona, WI). Specific patient records were filtered by cardiac arrest codes from the International Classification of Diseases 9th (995.91-995.92) and 10th (A41-A41.9) revisions, Clinical Modification. All RR encounters were recorded independently in a protected, web-based data bank, with a personal log in (New Innovations by New Innovations Inc.; Uniontown, OH). These encounters were then compared to those of car- diac arrest patients without RR resident participation. Encounters were compared using the patient’s medical record number (MRN). All Epic

Female (n = 381) 41 (10.76%) 340 (89.24%) 0.6835

Male (n = 504) 50 (9.92%) 454 (90.08%)

Initial rhythm of VFIB/VTACH

Yes (n = 105) 13 (12.38%) 92 (87.62%) 0.4508

No (n = 780) 78 (10.00%) 702 (90.00%)

Prior history of CAD

Yes (n = 395) 46 (11.65%) 349 (88.35%) 0.2306

No (n = 490) 45 (9.18%) 445 (90.82%)

There was no significant difference in baseline demographic variables between patients who had resuscitation resident involvement and those without (P >= 0.05).

Table 2

Effect of resident resuscitation involvement on 30-day mortality, multivariate analysis.

	Mortality with RR involvement	Mortality with No RR involvement	OR (95% CI)	P-value	Interact P
All patients	71.42%	66.36%	1.27 (0.76, 2.11)	0.3613	N/A
Biological sex of patient
Female	74.68%	63.59%	1.69 (0.76, 3.75)	0.1986	0.3458
Male	69.44%	68.82%	1.03 (0.54, 1.99)	0.9307
Initial rhythm of VFIB/VTACH Yes	54.78%	71.90%	0.47 (0.13, 1.66)	0.2430	0.0935
No	72.68%	63.39%	1.54 (0.87, 2.71)	0.1390
Prior history of CAD Yes	60.44%	50.94%	1.47 (0.76, 2.86)	0.2541	0.4844
No	79.21%	78.78%	1.03 (0.48, 2.21)	0.9470
Receipt of TTM Yes	73.55%	57.55%	2.05(0.61, 6.87)	0.2443	0.3871
No	74.81%	72.25%	1.14 (0.66, 1.98)	0.6409

In this multivariate analysis, there was no significant difference in the impact of resuscitation resident on 30-day mortality across the listed variables (Interaction P value >=0.05). The per- centages displayed are also adjusted percentages, which adjust for possible confounding variables.

had RR involvement died within 30 days, while 66.36% of patients who had no RR involvement died within 30 days (P = 0.3613).A multivari- ate analysis was also conducted to measure the effect of RR on provision of TTM across different baseline variables, which is depicted in Table 3. Our results showed a statistically significant increase in provision of TTM in patients who had RR involvement. 20.70% of patients who re- ceived RR also received TTM, while only 8.86% of patients who did not receive RR also received TTM (OR:2.69; P = 0.0025).

A univariate analysis was performed to analyze factors that affect 30-day mortality and its results are shown in Table 4. Patients who re-

Table 4

Baseline demographic variables and receipt of TTM, stratified by 30-day mortality.

Mortality No mortality P-value

Patient age in years
Mean (standard deviation)	69.70 (16.97)	63.41 (17.53)	< 0.0001
Patient body mass index (BMI)
Mean (standard deviation)	29.67 (8.74)	28.94 (8.11)	0.2859
Biological sex of patient
Female	265 (69.55%)	116 (30.45%)	0.9721
Male Receipt of TTM	350 (69.44%)	154 (30.56%)

ceived TTM were found to have a statistically significant lower 30-day	Yes	36 (52.94%)	32 (47.06%)	0.0020
mortality compared to those not receiving TTM. While 52.94% of pa-	No	579 (70.87%)	238 (29.13%)
tients who received TTM died within 30 days, 70.87% of patients who Initial rhythm of VFIB/VTACH

did not receive TTM died within 30 days (P = 0.0020). Older patients were found to have a statistically significant higher 30-day mortality compared to those who were younger. The mean ages for patients who died within 30 days compared to those that survived were 69.7 and 63.41 years, respectively (P < 0.0001). Patients without a history of CAD were noted to have a statistically significant higher 30-day mor- tality compared to those with a history of CAD (P < 0.0001). In the pa- tient population that experienced 30-day mortality, 78.16% did not have a history of CAD, while 58.6% did. All other variables between groups were not statistically significant.

1. Discussion

Our study found no statistical difference in 30-day mortality be- tween patients with RR involvement compared to those without (71.42% vs 66.36%; P = 0.3613). We suspect that this finding can be ex- plained by the fact that our RRs gravitate to cardiac arrest cases that re- quire more labor-intensive post-ROSC. However, our results

In this univariate analysis, there was a significant difference in 30-day mortality in patients who received targeted temperature management and those who did not. A statis- tically significant lower percentage of patients died when they received TTM compared to those that did not receive TTM. There was also a significant difference in 30-day mortality for age and history of coronary artery disease (CAD). Older age and not having a history of CAD were associated with higher 30-day mortality.

Yes	76 (72.38%)	29 (27.62%)	0.4934
No Prior history of CAD Yes	539 (69.10%) 232 (58.73%)	241 (30.90%) 163 (41.27%)	< 0.0001
No	383 (78.16%)	107 (21.84%)

demonstrated that RR involvement was associated with a statistically significant increase in the provision of TTM (20.70% vs 8.86%; P = 0.0025). Patients who received TTM also had a lower 30-day mortality compared to those not receiving TTM (52.94% vs 70.87%; P = 0.0020). Patients who experienced 30-day mortality were older in age than those who survived (69.6 years vs 63.41 years; P < 0.0001). Our results also depicted that not having a history of CAD was associated with a

Table 3

Effect of resident resuscitation involvement on receipt of targeted temperature management, multivariate analysis.

	Receipt of TTM with RR involvement	Receipt of TTM with No RR involvement	OR (95% CI)	P-value	Interact P
All patients	20.70%	8.86%	2.69 (1.42, 5.09)	0.0025	N/A
Biological sex of patient
Female	22.61%	19.37%	3.14 (1.18, 8.38)	0.0220	0.6826
Male	8.50%	9.10%	2.40 (1.03, 5.58)	0.0418
Initial rhythm of VFIB/VTACH Yes	22.49%	16.56%	1.46 (0.38, 5.60)	0.5793	0.3059
No	14.20%	4.87%	3.23 (1.59, 6.59)	0.0012
Prior history of CAD Yes	29.63%	13.71%	2.65 (1.18, 5.93)	0.0177	0.9571
No	14.04%	5.61%	2.75 (0.96, 7.89)	0.0604

In this multivariate analysis, there was a statistically significant impact of resuscitation resident on the receipt of targeted temperature management. The percentages displayed are ad- justed percentages, which adjust for possible confounding variables.

statistically significant higher 30-day mortality compared to having a positive history (78.16% vs 58.73%; P < 0.0001). We predict that this may be due to a variety of reasons. One certainly could be due to the lack of diagnosis of CAD; however, the unequal sizes and retrospective study design are likely contributing.

With this patient population, neurological injury remains as one of the most common causes of death after being successfully resuscitated from cardiac arrest. Multiple studies have shown the benefits of TTM on improved neurological outcome. Studies have also found a positive association with earlier induction of TTM and improved neurological outcome [3,4]. In our study, we were able to confirm these findings, as RR involvement led to the increased rate of initiation of TTM and a lower 30-day mortality in those that received TTM. Interestingly, Haugk et al. noted contradictory results, finding that rapid decreases in body temperature were actually associated with worsened neurolog- ical outcome. However, with no other clinical study to support their findings, their results remain hypothetical [5]. Therefore, to confirm the prognostic influence of TTM in future studies, it would be important to measure the impact of increased provision of TTM by RR on neurolog- ical outcome. In addition to TTM, it would be interesting to look at the potential role expansion of RR in other interventions such as trans- esophageal echocardiography (TEE). In their literature review, Parker et al. concluded that TEE could be helpful in the guidance of resuscita- tion [10]. In a different study, Teran et al. found TEE implementation in the management of cardiac arrest patients in the ED to be clinically impactful [11]. Therefore, it may be clinically important to assess if RR involvement could also lead to the increased provision of TEE in future studies.

To our knowledge, there are no other studies in previous literature describing the clinical benefits of implementing a focused Resuscitation Rotation in an EM residency. However, Hunziker et al. and Norris et al. looked into the benefits of having efficient teamwork and coordination in CPR performance and patient care [12-14]. There are also a number of studies that looked into educational improvements in resuscitation training. Taira et al. developed a novel resuscitation course that helped improve Nicaraguan residents’ abilities in managing cardiac arrest sim- ulations [15]. Hall et al. looked into the development of a new assess- ment tool in measuring competency in resuscitation [16]. Similarly, our Resuscitation Rotation was also designed to supplement the educa- tion of our residents. The educational benefits have been well docu- mented since the start of the program via a survey questionnaire, which consistently reported improved confidence and self-efficiency in residents’ resuscitative skills [9]. In addition, our department’s EM physicians have experienced expedited care in their patients who had RR involvement. As a result, we began to assess the impact of RR on pa- tient outcomes, which led to the assessment of RR impact on CPR pa- tients in this paper. Sepsis patients have also been assessed, and RR led to a statistically significant decreased time to measurement of initial lactic acid, as well as decreased times to receiving of antibiotics and fluid bolus, although these data points were not statistically significant [17]. Medical resuscitation is a vital component of patient care. Therefore,

it is imperative to adequately develop the ability to manage resuscita- tion cases during residency, and sustain this ability over the course of an EM physician’s career. However, there have been multiple problems reported in both the education and retention of resuscitative training. In their Scientific Statement from 2018, the American Heart Association described that current available educational opportunities regarding re- suscitation are lacking and have led to a decay in resuscitative skills over time [18]. In addition, it is important to consider that the varying expe- riences residents may have with resuscitation over the course of their training. Langdorf et al. reported wide inter-resident variability in pro- cedures and resuscitations over the course of an EM residency, and sup- ported the necessity of providing additional educational opportunities such as simulations, models, etc. [19]. Clearly, there is a need for im- provement in education regarding resuscitation, which our institution’s focused Resuscitation Rotation addresses. Our Resuscitation Rotation

provides a meaningful amount of time and experience with high acuity patients to our residents to supplement their training in resuscitation. Through this educational experience, we strongly believe that our resi- dents will not only be well prepared for future work with resuscitating patients, but also directly improve patient outcomes in the present.

This study has several limitations. First, data was retrospectively col- lected, making it difficult to control for confounding variables. In addi- tion, RR participation represented only 10.28% of the cases analyzed herein, thus the two arms are unbalanced in size. This discrepancy is likely explained by the fact that the RR resident is not available in the ED 24/7, and expectedly would not be present for all cardiac arrest pa- tients. Lastly, encounters where a RR resident was involved was logged at the discretion of the resident. For this reason, it is possible some en- counters had RR resident involvement that were not logged by error. However, after chart review on initial data collection, these errors were corrected when recognized. All in all, our data suggests a future prospective study may be necessary to fully appreciate the impact of a RR.

1. Conclusion

In conclusion, RR involvement with the care of cardiac arrest pa- tients had no impact in 30-day mortality. However, the involvement of RR was associated with a statistically significant increase in the initi- ation of TTM. Future work may investigate if the increase in TTM in the RR involved cases may portend improved rates of Neurologically intact survival or more rapid achievement of goal temperatures.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influ- ence the work reported in this paper.

Acknowledgements

We thank our ED colleagues whose help made the Resuscitation Ro- tation an educational success. We are very grateful to our statistician, for assistance with the electronic medical record query, without which the data collection would have been near impossible. Lastly, we would like to express our deep gratitude to our hardworking residents and their willingness to aid in advancing medical education.

Funding

None.

Presentation

Abstract accepted to orally present at SAEM20 Annual Meeting (can- celled due to COVID).

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