a b s t r a c t

Objective: This study analyzed outcomes associated with nurse-performed ultrasound (US)-guided intravenous

(IV) placement compared to standard of care (SOC) palpation IV technique on poor vascular access patients. Methods: This was a randomized, prospective single-site study. Phase 1 involved education/training of a cohort of nurses to perform US-guided IVs. This consisted of a didactic module and hands-on requirement of 10 proctored functional IVs on live subjects. Phase 2 involved patient enrollment. emergency department patients meeting strict criteria of poor access were randomized to US-guided or SOC palpation arm. A functional IV placed by a study nurse was considered successful. Unsuccessful placement implied the study nurse failed, and a rescue IV was attempted. Time to IV placement was the total time required to obtain a functional IV and, if needed, a rescue IV. Results: A total of 124 subjects were enrolled; 63 were randomized to the US-guided arm, and 61 were randomized into the SOC arm; 2 patients were excluded, leaving 59 patients. Success rate was 76% for the US-guided arm and 56% for the SOC arm (P = .02). Compared to the SOC arm, the odds ratio for success for the US-guided arm was

2.52 (95% confidence interval, 1.09-5.92). The mean time to IV placement for the US-guided arm was 15.8 and

20.7 minutes for the SOC arm (P = .75).

Conclusion: In difficult access patients, nurses were more successful in obtaining IV access using US guidance than palpation SOC technique. Lengthier placement times were observed more frequently when the SOC IV technique was used.

(C) 2016

Introduction

Establishment of Intravenous access remains one of the most piv- otal steps in providing care to patients within the emergency department (ED). Obtaining vascular access in a timely manner is necessary to opti- mize the evaluation and stabilization of critically ill patients. Therefore, successful IV cannulation is a factor that significantly impacts patient care. On the contrary, delay in the establishment of vascular access often impedes diagnostic testing, including Laboratory analysis and radiology evaluation, and thereby prevents the efficient treatment and disposition of patients. The typical palpation IV technique Cannulation time has been reported as 2.5 to 12.6 minutes, with patients with difficult IV ac- cess requiring as much as 30 minutes and upward [1-5]. Consequently, a

? Meetings: Bagan M, Bahl A. Comparison of nurse-performed ultrasound-guided versus standard of care intravenous access in emergency department patients with difficult access. American College of Emergency Physicians October 2015 National Meeting (Boston, MA).

?? Grant support: Blue Cross Blue Shield of Michigan Physician Investigator Award Number

2069.

? Conflict of interest: None.

* Corresponding author.

E-mail address: [email protected] (A. Bahl).

delay in IV establishment diminishes the ability to deliver necessary medical care in a timely fashion.

Historically, nurses have been entrusted with establishing IV access. At times, starting an IV may pose a challenge to even the most experi- enced and skilled nurses. Patients with a medical history of obesity, IV drug abuse (IVDA), end-stage renal disease , and/or Sickle cell disease have been shown to have poor vascular access [6-9]. When nurses are unable to obtain IV access in these patients, physicians are subsequently requested to attempt vascular access. As a result, these pa- tients are often subjected to numerous IV placement attempts by multi- ple practitioners-which not only causes significant pain to the patient but also consumes considerable resources and time [10,11]. Ultimately, as a last resort, these patients often have to undergo Central venous catheter placement to obtain IV access. However, CVC placement is a time-consuming and invasive procedure which carries a high risk of complication-including significant Arterial puncture, pneumothorax, and infection [12].

The existing literature supports the use of ultrasound (US)-guided peripheral IV placement as a safe alternative to palpation IV technique and CVC placement to establish vascular access, especially in patients with difficult IV access [1,5,13-15]. Multiple studies have shown that ED physicians are successful in obtaining IV access using US guidance

http://dx.doi.org/10.1016/j.ajem.2016.06.098

0735-6757/(C) 2016

[1,5,8,13,16]. Although ED physicians are skilled at placing US-guided peripheral IVs (USGPIV), this takes time away from their routine workflow. In addition, physicians are usually only called on to establish IV access after all options have been exhausted, often leading to signifi- cant delays in a patient’s diagnostic testing and subsequent treatment. Currently, there is limited randomized, prospective research supporting the use of US-guided IV placement for ancillary staff [17]. It is the next logical step to train ED nurses to use US-guidance to improve their abil- ity to place a peripheral IV in these challenging patients. The emergency nurses Association 2011 Resolution concluded that US-guided IV place- ment by ED nurses will decrease time to treatment, increase patient sat- isfaction, and decrease ED length of stay [18]. Our study helps to clarify the role of nurses in performing this procedure.

The purpose of this study is to assess whether ED nurses trained in US-guided IV placement could have better success in placing IVs in dif- ficult access patients using US guidance as compared to nurses placing IVs in these patients using the standard of care (SOC) palpation tech- nique. Furthermore, we aim to understand the total time required to ob- tain a functional IV when IV access is initiated in this patient population using either US guidance or SOC technique both when the nurse is suc- cessful and also if the nurse is initially unsuccessful at IV placement and a rescue vascular access option is needed.

Methods

Study design and setting

This was a prospective, nonblinded, randomized controlled trial com- paring nurse-performed US-guided vs SOC palpation technique for IV placement in difficult access patients. The study was conducted at a single-site, tertiary care, level I trauma center with an annual ED census greater than 125 000 visits. Patient enrollment took place from November 2014 to July 2015. This study was approved by the institutional review board at our institution, and signed informed consent was obtained by a trained researcher for each enrolled patient. This study received funding from Blue Cross Blue Shield Foundation of Michigan. A Wilcoxon-Mann- Whitney test was used to calculate the sample size needed to achieve 80% power at a significance level of 0.05. The distributions for both groups was assumed to be exponential. Mean times to IV success for experimen- tal and control groups were extrapolated from existing literature.

Nurse enrollment

This study was segmented into 2 phases. During phase 1, an educa- tional program was established to train currently employed ED nurses. All ED registered nurses with at least 2 years of experience and in good clinical standing were notified of the study, including its demands, and of- fered the ability to participate. The registered nurses who expressed a de- sire to participate were randomized into either the US-guided or the SOC method of obtaining peripheral IVs. Nurses were assigned to a study arm using block randomization from the SAS program by biostatistical staff at our institution’s research institute. The study nurses had no previous for- mal training in US or using US for vascular access. Ten nurses were ran- domized to the US arm, and 10 nurses were randomized to the SOC arm.

Nurse training

Two educational programs, which took place from September 2014 to October 2014, outlined the techniques necessary to obtain IV access in chal- lenging patients through the corresponding method of US guidance or SOC. The didactic sessions, which included a Microsoft PowerPoint presentation, spanned 1.5 hours. The US group also viewed a short video by the New En- gland Journal of Medicine demonstrating IV placement technique under US guidance; this was followed by a hands-on session in which nurses familiar- ized themselves with the US equipment and upper arm sonographic anat- omy [19]. After completion of the US-guided education program, nurses in

this group were required to obtain 10 supervised successful IV placements using the 1-person US guidance technique, before being certified. Supervi- sion of US-guided IV placement was performed by US-trained emergency physicians and a cohort of US credentialed nursing leadership.

Selection of participants

Phase 2 consisted of a randomized prospective cohort study. A conve- nience sample of patients, presenting to the ED, was enrolled and ran- domized into 1 of the 2 proposed IV cannulation methods-US-guided peripheral IV placement or SOC. Initial screening was carried out by the ED staff, shortly after patient arrival. Research assistants carried out re- cruitment and enrollment during regular business hours on weekdays.

Patients eligible for the study were required to meet all variables of in- clusion criteria, A through D, as outlined in Table 1. Patients were exclud- ed if they (1) did not meet inclusion criteria; (2) had participated in the study prior; (3) had already undergone an attempt at vascular access, ei- ther by emergency medical services or by ED staff; or (4) the enrollment process had the potential to delay their care. Study participation was purely voluntary, and written informed consent was obtained. Upon re- ceiving consent, sealed envelopes containing the randomized IV access technique were revealed at bedside. The randomization scheme with varying block sizes was created by a biostatistician using a computer- generated program. After randomization, the appropriate study-trained nurse was attained to attempt placement of a peripheral IV. Study nurses in the US arm used a Sonosite M-turbo US machine with a high-frequency linear transducer for US-guided IV placement.

Methods and measurements/data collection

A functional IV was confirmed by extraction of 5 mL of nonpulsatile blood and/or infusion of a 5-mL normal saline flush, without evidence of extravasa- tion. For this study, after a patient was randomized into a study arm, the study nurse was encouraged to make 2 attempts at vascular access before aborting their IV attempts and seeking an alternative rescue method. After all the equipment, materials, and machinery were gathered, then start time was ini- tiated when the study nurse first placed the tourniquet on the patient.

If the nurse in either study arm failed in IV placement, the patient remained in the study, and a rescue IV was attempted at the discretion of the primary treatment team per routine care of a difficult IV. Options for obtaining a rescue IV included (1) US-guided IV by another study nurse, res- ident, or staff physician; (2) traditional palpation IV technique by another nursing team member; (3) peripheral intravenous central catheter (PICC) placement by the hospital PICC team; or (4) CVC placement by a resident or staff physician. Once a functional IV was obtained and the tegaderm was positioned over the IV, the time was again recorded as the stop time. This start to stop time established a tourniquet-to-tegaderm time.

The data collection at bedside from both study arms included medical history (ESRD, sickle cell disease, and IVDA), Blood pressure and heart rate on arrival, number of IV attempts, and tourniquet-to-tegaderm time. The data collected through the electronic medical record included age, sex, and body mass index. Table 2 illustrates the demographic data that were collected and analyzed.

Table 1

Study subject inclusion criteria

18 years or older

Identify themselves as being someone who has a history of being a

“difficult stick”

Experienced at least 1 previous episode where 2 or more attempts were required to obtain a peripheral IV

At least one of the following:

• Prior history of a rescue catheter as the result of an inability to obtain a peripheral IV
• History of ESRD
• History of IVDA
• History of sickle cell disease

Table 2

Patient characteristics in experimental and SOC groups

study nurse placed a functional IV after the patient was assigned ran- domization to the US or SOC group. IntraVenous placement was defined

.83

	USGPIV (n = 63)	SOC (n = 59)	P value (for overall group)	as unsuccessful if the initial study nurse failed and a rescue method was needed to ultimately obtain a functional IV. Time to IV placement, also
Age (median years)	61	62	.96a	known as tourniquet-to-tegaderm time, was defined as the total time
18-35	6 (9.5%)	9 (15.3%)		interval to achieve functional vascular access and included the time re-
36-50	12 (19.0%)	11 (18.6%)		quired to obtain a rescue IV, if necessary.
51-65	25 (39.7%)	17 (28.8%)
65+	20 (31.7%)	22 (37.3%)
Sex			b	2.7. Data analysis
Male	16 (25.4%)	16 (27.1%)
Female Medical history	47 (74.6%)	43 (72.9%)	The 2 study arms were compared on demographic and clinical char- acteristics. To compare results between the 2 study arms, Wilcoxon

Obesity (BMI >=30) 36 30 .49^b

IVDA 3 1 .62^c

ESRD 16 12 .37^b

Sickle cell 1 1 1.00^c

HR (median) 84 88 .46^a

MAP (median) 50-70 71-100	91 4 (6.4%) 41 (65.1%)	95 .28a 3 (5.3%) 32 (56.1%)	for the odds ratio, which was calculated using StatXact 10. Two-sided P values less than .05 were considered statistically significant.
101-130	17 (27.0%)	21 (36.8%)
N130	1 (1.6%)	1 (1.8%)	3. Results

rank sum tests were used for continuous data, whereas ?² or Fisher exact test was used for categorical data. Intent-to-treat analysis was used. The SAS System for Windows version 9.3 was used to calculate all statistical tests with the exception of the confidence interval (CI)

Abbreviations: BMI, body mass index; HR, heart rate; MAP, mean arterial pressure.

^a Wilcoxon rank sum analysis.

^b ?² Analysis.

^c Fisher exact analysis.

Outcomes/definitions

Our primary outcomes for this study were IV success rate and time to IV placement. Intravenous placement was defined as successful if a

Randomized n = 124

Excluded n = 2 (a)

USGPIV Arm n = 63

SOC Arm n = 59

Succesful n = 48

Successful n = 33

Unsuccessful n = 15

Unsucessful n = 26

PICC line placed

n = 2

SOC IV

attempted n = 6

USGPIV

attempted n = 7

USGPIV

attempted n = 20

SOC IV

attempted n = 4

Other

n = 2 (b)

SOC IV

a

ttempted

n = 2

PICC line placed

n = 1

USGPIV

attempted n = 1

USGPIV

attempted n = 1

Functional IV n = 2

Functional IV n = 1 (e)

Functional IV n = 1

A total of 124 patients consented and were enrolled into the study; 63 subjects were randomized into the US guidance arm, and 61 subjects were initially randomized into the SOC arm, but 2 patients were exclud- ed due to the lack of availability of a study-trained SOC nurse, leaving 59 patients in the study arm. Fig. 1 demonstrates a summary of the results of the 2 study arms and how a functional IV was obtained.

Table 2 illustrates the patient demographics and shows that there was no statistical difference in the patient population with regard to

Functional IV	Failed	Functional IV	Failed	Functional IV	Failed	Functional IV
n = 6	n = 3 (c)	n = 4 (d)	n = 1	n = 19	n = 1	n = 3

USGPIV=Ultrasound-Guided Peripheral IV SOC= Standard of Care PICC=peripheral intravenous central catheter

^(a) 2 patients were randomized initially to SOC but excluded due to lack of study nurse availability

^(b)1 patient received a failed femoral access attempt by a staff physician and discharged; 1 patient left AMA after receiving one attempt at a peripheral IV

^(c)1 attempt by resident physician

^(d) 1 patient’s IV was placed by a staff physician

^(e)IV was placed by resident physician

Fig. 1. Study subject randomization and pathway to functional IV line placement. ^(a)Two patients were randomized initially to SOC but excluded due to lack of study nurse availability. ^(b)One patient received a failed femoral access attempt by a staff physician and discharged; 1 patient left against medical advice after receiving one attempt at a peripheral IV. ^(c)One at- tempt by resident physician. ^(d)One patient’s IV was placed by a staff physician. ^(e)IV was placed by resident physician.

USGPIV=Ultrasound-Guided Peripheral IV SOC= Standard of Care

Fig. 2. Time to IV line placement comparing experimental and SOC groups.

age, sex, obesity, IV drug use, ESRD, sickle cell disease, heart rate, or mean arterial pressure.

The success rate for IV placement was 76% (48/63) for the US-guided arm and 56% (33/59) in the SOC arm (P = .02). The odds ratio for suc- cess for the US guidance arm was 2.52 (95% CI, 1.09-5.92) times the odds of success for the SOC arm.

The distribution of time to IV placement data in the 2 arms is displayed in the box plot (Fig. 2). The US-guided IV arm displayed the following tourniquet-to-tegaderm times: a minimum of 3.0 minutes, 25th percentile of 5.4 minutes, 75th percentile of 17.8 minutes (95% CI, 13.2-23.5), and maximum of 125 minutes. The SOC arm displayed the following tourniquet-to-tegaderm times: a minimum of 1.5 mi- nutes, 25th percentile of 3.5 minutes, 75th percentile of 36.6 minutes (95% CI, 23.1-45.6), and maximum of 86 minutes. The mean tourniquet-to-tegaderm time for the US-guided IV arm was 20.7 mi- nutes, and the mean for the SOC arm was 15.8 minutes (P = .75).

The US-guided IV arm displayed a mean of 1.52 IV attempts per sub- ject, and the SOC arm had a mean of 1.71 attempts per subject (P = .63).

Discussion

Our study showed that, when a patient is initially identified to have difficult vascular access and a nurse initiates IV access using US-guided vs SOC technique, there was a significant difference in success rates for the 2 study arms. A nurse using the US-guided technique had a higher success rate of 76% in placing a functional IV compared to 56% using the SOC palpation technique. Only 1 other study has evaluated nurse-placed, US-guided IV vs SOC using a prospective, randomized study protocol. This study had a smaller population of 50 patients and showed no statistical difference in success rate between the 2 groups [17]. However, with a larger sample size, our study showed that the suc- cess rate of nurse-placed, US-guided IV is on par with the success rate of 80.5% to 97% demonstrated in other studies evaluating US-guided IV placement vs SOC by physicians and ED technicians [1,14]. Improved IV placement success implies less physician involvement, as exempli- fied in our study in which a physician intervened in only 4 cases, and ad- ditionally decreases the need for CVC placement, also illustrated in our study with no CVCs placed.

The second outcome assessed was the IV placement time. We de- fined time to IV placement as the total time interval to achieve function- al vascular access and included the time required to obtain a rescue IV, if necessary. In patients selected to have difficult vascular access, our study did not find evidence of a statistically significant difference in the time to IV placement when a nurse initiated an IV using US guidance compared to palpation SOC technique. We believe that there were 2 major factors that led to this lack of difference. First, a US-credentialed nurse was able to use US guidance to place an IV as a rescue option in the SOC arm. Ideally, we preferred to withhold US-guided IV placement by a nurse in the SOC arm; we wished to mimic the routine care of a dif- ficult access patient in which physician workflow would be interrupted and the physician would be responsible for inserting a functional vascu- lar access device, with an associated increase in time to IV placement. However, study investigators concluded that it would be unethical to withhold the rescue option of a nurse-placed, US-guided IV from pa- tients. In our study, most patients with unsuccessful IV attempts in the SOC arm were rescued by a nurse-placed, US-guided IV (83%; 20/24 cases). The SOC study nurse’s access to this alternative IV rescue method likely led to shorter tourniquet-to-tegaderm times in the SOC arm.

In addition, the lack of difference in time to IV placement also may be

related to our inability to control for the number of IV sticks attempted by the study nurse before an IV method was deemed unsuccessful. This study was designed to be a nurse driven protocol, so as to mirror the real world. Therefore, nurses determined the appropriate clinical steps for vascular access. Study nurses were encouraged, but not required, to make 2 attempts before abandoning an IV study method. However, be- cause nurses were aware that IV rescue via US was a viable option, we suspect that this led to nurses aborting their cases early. Because tourniquet-to-tegaderm time included the time to US-guided IV rescue, we feel that this rescue method greatly impacted both the number of at- tempts and the time to placement data.

Despite lacking statistically significant variation in the typical time to IV placement, if we dissect our data further, we are still able to show that, in a patient with difficult vascular access, it is less time consuming for a nurse to initiate IV access using US guidance than the SOC tech- nique. If we explore the time to IV placement in most of our patients and analyze the 75th percentile, we see that there is a statistical differ- ence in time to IV placement. Seventy-five percent of the patients in the US-guided IV arm obtained IV access in less time, requiring 17.8 minutes compared to 36.6 minutes in the SOC arm. Furthermore, if we look at the upper limits of our study and compare the frequency of patients having IV placement times exceeding 33 minutes, this occurred in only 10% of the US-guided IV group compared to 27% in the SOC group. If one is con- cerned about delay in treatment, due to increased time to IV placement, our study suggests that lengthier times occur more frequently when SOC technique is used compared to US-guided IV.

There are several design methodologies that make our study unique

to previous studies that evaluated US-guided IV placement by ED ancil- lary staff. First and foremost, our study had a robust training program for our nurses in our US-guided arm. This training included both a didactic portion and a certification process requiring the proctored placement of 10 functional IVs on Live patients. No previously reported study to our knowledge incorporated training on live patients and thereby did not account for provider competency in placing US-guided IVs [6,14,16,17,20-23]. We eliminated an important confounding variable by ensuring all the nurses in our study had a uniform level of training in performing the technique of US-guided IV placement. Furthermore, we also ensured uniformity in our SOC group by requiring the study nurses to be in good standing and to have 2 years of experience in emer- gency care; this provided assurance that each nurse had significant ex- perience in the placement of IVs in difficult access patients.

A second distinctive study design was the strict inclusion criteria

used to select our difficult vascular access patients. Most previous US- guided IV studies identified patients as having difficult access once they had failed 2 to 3 palpation IV attempts and used US-guided IV as

a rescue method [6,14,16,17,20-23]. In contrast, our study aimed to study how US-guided IV placement served as a tool in the initiation of IV access and excluded patients who had already had a palpation IV at- tempt. Furthermore, unlike other studies, once patients were targeted based on self-identification as being a “difficult stick,” they needed to meet further inclusion based on a medical history which predisposes patients to difficult vascular access. In being highly selective in our pa- tient enrollment, we ensured that the IVs placed by the nurses in our study were truly on patients with poor vascular access.

Our strict Selection process is further validated when evaluating the caliber of IVs placed in those patients where US-guided IV placement was unsuccessful and was rescued with SOC IV placement. In these 8 pa- tients, data on the type of IV placed were not available on 2 patients, and of the remaining patients, the majority (5/6 patients) had 22-G IVs placed, 3 of which were in a hand or a foot. The only accessible IV pro- vided to these patients was small gauged and located in small superficial veins. These data reinforce our highly selective inclusion criteria and support that truly difficult IV access patients were included in our study.

Limitations

This study had several limitations. It was performed at a single site, and thereby, we were unable to externally validate our findings. We are a tertiary referral center with a highly complex patient population and frequently encounter difficult vascular access patients. Other sites may not have a similar frequency of disruption to the physician workflow, in regard to vascular access issues that we encounter making our results po- tentially less generalizable. In addition, our study did not take into account the time it took to obtain the US machine as the machines are readily available in each module of our ED and, therefore, the time to obtain a ma- chine was minimal. Other EDs may not have such easy and quick access to US machines and, therefore, might cause delays when IVs are placed under US guidance. Furthermore, secondary to efforts to create a nurse- driven study and represent true occurrences within the ED, we were un- able to standardize the minimum number of IV attempts performed on each patient by study nurses before they aborted their designated IV placement technique. We feel that this affected our time to IV placement data and likely underestimates the time to placement for the SOC group. Finally, in the SOC arm when the study nurse was initially unsuccessful at IV placement, we were unable to withhold a nurse placed US-guided IV as a rescue option. This prevented our SOC arm from being a true control arm in which the patients in this study arm would have followed the typ- ical pathway for IV access, where nurse-placed, US-guided IV access would have been unavailable.

Conclusions

Frequently, patients with difficult vascular access are seen in the ED. In patients whom obtaining vascular access is a challenge, awareness and proper utilization of resources become vital to quality Health care delivery within the ED. Our study showed that when nurses, who underwent formal training for US-guided IV placement, were presented with a patient with difficult vascular access, they were more successful in obtaining IV access using US guidance than nurses who used palpa- tion SOC technique. We also identified that when IV access is initiated in patients with difficult IV access, lengthier time to placing a functional IV occurred more frequently when nurses used the SOC IV technique compared to the US-guided IV method.

In summary, we recommend implementation of the following pa- rameters to improve the success rate of IV placement and the reduction of IV placement times by ED nurses: (1) implement a robust training program for nurses which includes supervised placement of US- guided IVs on live patients; (2) recognize patients with known difficult vascular access early in their triage process; and (3) when a patient with difficult vascular access is identified, initiate IV access with US guidance rather than using it as rescue method after failed palpation IV attempts. Future research should target patient satisfaction with US-guided IV placement and the impact of this intervention on ED length of stay.

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