a b s t r a c t

Introduction: Previous studies have identified obesity as a risk factor for difficult IV access, but this has not been studied in the acute trauma setting. The primary objective was to determine if obesity is associated with in- creased difficulty placing peripheral IVs in trauma patients. Secondary analysis evaluated IV difficulty and asso- ciations with nursing self-competence ratings, trauma experience, and patient demographics.

Methods: Prospective, observational study at academic level I trauma center with 58,000 annual visits. Trauma activation patients between January and October of 2016 were included. Each nurse who attempted IV place- ment, completed anonymous 7 question survey, including trauma experience (years), self-competence and IV difficulty (Likert scales 1-5), and attempts. Demographic and clinical information was retrospectively collected from the EMR and nursing surveys. Descriptive statistics, chi-square tests, and spearman correlations were used. Results: 200 patients included in the study with 185 BMI calculations. 110 overweight (BMI N 25) and 48 obese (BMI N 30). 70 (35%) female, 149 (75%) white, average age 48. Increased BMI and IV difficulty displayed spear- man correlation (?) of 0.026 (P = 0.72) suggesting against significant association. Increased trauma experience and self-competence ratings significantly correlated with decreased IV difficulty, ? = -0.173 and -0.162 (P = 0.010 and 0.014). There was no statistically significant association with IV difficulty in regards to Patient race, age, sex, or location of IV placement.

Conclusion: Obesity was not associated with increased difficulty in placing peripheral IVs in trauma activation pa- tients. Nurses with greater trauma experience and higher self-competence ratings, had less difficulty inserting IVs.

(C) 2020

Introduction

The placement of peripheral venous catheters is one of the most common procedures performed in the emergency department [1,2], with recent literature suggesting N25% of patients end up with an intra- venous (IV) line [3,4]. Failure to acquire IV access can significantly im- pact patient care ranging from a delay in laboratory results and diagnostic testing, to the inability to administer critical medications,

? Lightning Oral Presentation: Society of Academic Emergency Medicine (SAEM) Annual Meeting, Orlando, FL, May 19, 2017.

* Corresponding author at: 981150 Nebraska Medical Center, Omaha, NE 68198-1150, United States of America.

E-mail addresses: [email protected] (A.N. Barksdale), [email protected] (M. Goede), [email protected] (S. Madden), [email protected] (A. Campos), [email protected] (R. High).

fluids, or blood products [2,5]. In those critical patients, this often neces- sitates more invasive measures such as intraosseous (IO) needle or cen- tral venous catheter (CVC) placement, which in turn can lead to increased complications and hospital lengths of stay [1,6].

Numerous factors have been associated with increased difficulty in IV placement, including patient age, skin tone, prior IV drug use, patient hydration status, and Provider experience. In addition, several studies have reported a significant correlation between obesity and IV Failure rates [3,7-9]. Over the past decade, obesity has continued to be a major health crisis, with over 500 million individuals worldwide and nearly a third of the United States population [10,11]. This trend is also prevalent in the trauma patient population. Recent literature has demonstrated that morbidity and mortality is likely increased in the obese trauma patient, but to our knowledge no study has evaluated the difficulty of IV placement in this patient population [12,13]. Early

https://doi.org/10.1016/j.ajem.2020.05.028

0735-6757/(C) 2020

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venous access is a critical component in the resuscitation of trauma pa- tients, and if a correlation between obesity and IV difficulty exists, it could potentially have an effect on patient outcomes.

The primary objective of this study was to determine if there was a significant correlation between obesity and increased IV placement dif- ficulty in trauma activation patients. Our a priori hypothesis anticipated that such an association would indeed exist. Secondary analysis evalu- ated IV difficulty and potential associations with nursing self- competence ratings, trauma experience, and other patient demo- graphics including; race, age, sex, or location of IV placement.

Methods

This was a prospective observational study and received approval from the local institutional review board.

This study was conducted at an academic level I trauma center with an emergency medicine residency and approximately 58,000 annual patient visits. All patients who met trauma activation criteria between January 1st and September 30th of 2016, were included in the study.

The trauma activation team at our institution includes a mixture of emergency and trauma surgery physicians, a respiratory therapist, an emergency medicine tech, and two registered nurses (RNs). Consistent with Advance Trauma Life Support (ATLS) venous access begins with the placement of two large bore peripherals IVs by the RNs, followed by more invasive measures such as an IO or CVC if deemed necessary by the trauma team. Following conclusion of the trauma resuscitation, each nurse who attempted to place an IV immediately filled out a seven question survey that included the following questions; number of clinical years in a trauma center, their perceived IV placement skill level (Likert scale 1-5), difficulty in placing that individual’s IV (Likert scale 1-5), number of attempts, and location of IV (see Fig. 1). The sur- veys were then placed in a locked drop block, secured to a wall in the trauma bay, which was labeled “Trauma IV Study”. Three weeks preced- ing the initiation of this study, all emergency RNs were given education on the survey process. Of important note, no individuals besides the

authors of this manuscript were aware that obesity was a variable being evaluated in this study.

Biweekly, surveys were collected and information recorded into a secure data form. Additional descriptive data was extracted from our electronic medical record (EMR) including; BMI, age, race, gender, lan- guage, payor status, and disposition.

The primary objective was to determine if there was a statistically significant correlation between obesity and increased difficulty in pe- ripheral IV placement. A secondary analysis explored whether signifi- cant correlations existed between difficulty and the following variables: RN years of experience, RN self-competency rating, number of attempts, IV location, gender, age, race, language, payor status, and disposition.

Descriptive statistics were used to summarize patient characteris- tics. P-values from Exact Pearson chi-square tests were used to evaluate the categorical variables with IV difficulty. Spearman correlations with exact P-values summarized relationships between the continuous data and IV difficulty. All analyses were performed with SAS/STAT software, Version 9.4. P b 0.05 was considered statistically significant. Due to a lack of published data on IV difficulty in obese trauma patients, we used a standard correlation coefficient table to calculate our sample size [14]. Using a coefficient of 0.3 would suggest a better than “weak” correlation, and with a two sided analysis of variance and a 90% power, we would need a sample size of 113 subjects in order to detect a true difference at the 0.05 level (?). However, we opted to enroll a larger number of patients to account for potential incomplete data in some subjects.

Results

Over a nine-month period, 200 patients and 211 surveys were in- cluded in the study. Of these subjects 130 (65%) were male, 151 (76%) were white and 27 (14%) were African American, with a mean age of 48 years. BMIs were calculated in 185 patients (15 lacked complete data) with 59% of the subjects having a BMI N25 and 48 (26%) of the pa- tients fell into the obese or extremely obese categories (Table 1). There

Fig. 1. Nursing assessment survey of peripheral Intravenous line placement in trauma patients.

A.N. Barksdale et al. / American Journal of Emergency Medicine 38 (2020) 1875-1878 1877

Table 1

Patient descriptive statistics.

	Variable							Variable	N	%
	Age (years)		48 (average)					Nursing trauma experience

Table 2

Results of nursing peripheral IV placement survey.

English 185 92.5

	N	%	b3 years 3 to 5 years	74 52	37.0 26.0
Sex			6 to 10 years	49	24.5
Male	130	65.0	N10 years	23	11.5
Female	70	35.0	Not reported	2	1.0
Total	200	100.0	Total	200	100.0
Race
White	151	75.5 Number of IV attempts
Black	27	13.5	1	175	82.9
Hispanic	16	8.0	2	27	12.8
Other	6	3.0	3	8	3.8
Total	200	100.0	4	1	0.5
			Total	211	100.0
	Language

Reported IV placement difficulty^a

Spanish	10	5.0	1	126	59.7
Other	5	2.5	2	44	20.8
Total	200	100	3	21	10.0
			4	15	7.1
Unable to calculate	BMI category 15	7.5	5 Total	5 211	2.4 100.0
Normal (b25)	75	37.5
Overweight (25-30)	62	31.0		Reported IV placement skill level
Obese (30-40)	42	21.0	1	0	0.0
Extremely obese (N40)	6	3.0	2	1	0.5
Total	200	100.0	3	27	13
			4	118	55.9
			5	65	30.8
IV location Antecubital 124 58.8			Total	211	100.0

Hand 33 15.6

Foot 5 2.4

Wrist 5 2.4

Forearm 38 18.0

^a “Placement difficulty” and “skill level” are Likert scales ranging from 1 to 5. See Fig. 1 for more specific detail.

Table 3

Other	6	2.8
Total	211	100.0

Spearman correlation measurements of association in IV placement difficulty and study variables.

correlation

Yes No	IV prior to arrival 153 58	72.5 27.5		Variable	Spearman	95% CIa	P-value
Total	211	100.0		Patient age	0.112	-0.023, 0.248	0.103
				BMI	0.026	-0.115, 0.167	0.72
				Nursing trauma experience	-0.173	-0.304, -0.042	0.013
				Nurse reported IV placement skill level	-0.162	-0.291, -0.033	0.020

were 211 IV attempts with the antecubital area (59%) and hand (16%) being the most common locations, and 73% of patients arrived with one IV already placed. The majority of the RNs (62%) had N3 years of trauma experience with 12% reporting N10 years. Sixty percent of IV at- tempts were reported as minimally difficult where only 2.4% were con- sidered very difficult. No nurse reported their skill level as a 1, whereas 183 (87%) considered their IV placement ability to be a 4 or 5 (Table 2). Increased BMI and IV difficulty displayed a spearman correlation of

0.026 (95% CI: -0.115, 0.167, P = 0.72), suggesting against a significant association. Increased years of nursing trauma experience and self- competence ratings showed statistically significant correlations with decreased IV difficulty, with spearman correlations of -0.173 and

-0.162 (95% CI: -0.304, -0.042, P = 0.010 and 95% CI: -0.291,

-0.033, P = 0.014) (Table 3). There was no statistically significant asso- ciation with IV difficulty in regards to patient race, age, sex, or location of IV placement.

Discussion

The primary purpose of this study was to determine if there was a correlation between difficult peripheral IV placement and obesity in trauma activation patients, and to our knowledge this is the first to eval- uate this specific process. In this single center, prospective observational

Number of IV attempts 0.530 0.419, 0.641 b0.001

Difficulty was negatively associated with increased nursing experience and higher self-re- ported IV placement skill.

^a CI - confidence interval.

study, our results suggest that there is no significant correlation. Adding to the strength of this finding, 73% of our subjects arrived with at least one peripheral IV, allowing the assumption that Prehospital personnel had already utilized one of the more visible and accessible peripheral veins. In addition and as expected, nurses with increased trauma expe- rience and those who rated themselves higher on the self-competency scale had less difficulty with IV placement.

The prevalence of obesity continues to rise in the United States, with reports as high as 40% and predictions that this number could surpass 50% by the year 2030 [15]. Numerous studies have evaluated the impact of obesity on trauma patients, with the majority reporting an increase in morbidity and in some, a mortality increase of nearly 30% [12,13,15-17]. Prior research has described a significant association between obesity and difficult IV placement, but none have evaluated for this correlation in trauma patients and many studies excluded patients who were criti- cally ill, hypotensive, or in shock [3,7,11].

1878 A.N. Barksdale et al. / American Journal of Emergency Medicine 38 (2020) 1875-1878

Anecdotally, the authors collectively agreed that our nurses seemed to have less success placing IVs in our overweight patients. Along with the fact that immediate intravenous access is a critical component in the management and resuscitation of trauma patients and the lack pub- lications evaluating this process in obese patients, is what prompted us to conduct this study. A priori we hypothesized that there would be a significant correlation between obese trauma patients and difficult pe- ripheral IV placement. If found to be conclusive, we planned to use that data to drive implementation of trauma protocols which directed providers to utilize alternative methods of intravenous access after two failed attempts. As one would expect after reviewing these surpris- ing results, our current trauma Resuscitation protocols have remained unchanged. Adding to the strength of our findings, we well succeeded our calculated sample size of 113 subjects, no patients were excluded, and outside of the authors no one else was aware that this study was specifically evaluating obese patients.

This study is not without limitations. First, it was a single center de-

sign. Even though it was appropriately powered, it would be unreason- able to extrapolate these findings to all other level one trauma centers. Second, we did not adjust for certain factors that could have contributed to increased difficulty such as, chronic medical conditions, patients on hemodialysis, hypotension, or history of IV drug use. That being said, we feel that the fact we did not exclude any patients that were critically ill or in shock, could be viewed as a strength of this study. Third, we did not have a process in place to adjust for potential selection bias in whether nurses were more likely to complete the survey if they were successful in IV placement versus not. We can attest that our data showed that nearly 20% of our patients required more than one IV at- tempt. Finally, the degree of difficulty was determined subjectively per Likert scale by the nurse or nurses who attempted the IV. We did not perform any standardization training for this grading process, which could have varied from nurse to nurse.

In conclusion, increased difficulty in placing peripherals IVs was not

associated with obesity in trauma activation patients. Nurses with greater trauma experience and higher self-competence ratings, had less difficulty inserting IVs in this patient population.

Disclosure

The authors declare no conflicts of interest and there was no funding for this study.

CRediT authorship contribution statement

Aaron Nathan Barksdale:Conceptualization, Methodology, Investi- gation, Formal analysis, Writing - original draft.Matthew Goede:

Methodology, Investigation, Formal analysis, Writing - original draft. Scott Madden:Methodology, Investigation, Formal analysis, Writing - original draft.Abraham Campos:Formal analysis, Writing - original draft.Robin High:Formal analysis, Writing - original draft.

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