Clinical and demographic factors associated with pediatric difficult intravenous access in the operating room

Abstract Background Pediatric intravenous catheter insertion can be difficult in the operating room due to the technical challenges of small diameter vessels and the need to rapidly gain intravenous access in anesthetized children. Few studies have examined factors associated with difficult vascular access in the operating room, especially accounting for the increased possibility to use ultrasound guidance. Aims The primary aim of the study was to identify factors associated with pediatric difficult vascular access in the operating room. Our primary hypothesis was that Black race, Hispanic ethnicity, and ultrasound use would be associated with pediatric difficult vascular access. Methods We performed a retrospective analysis of prospectively collected data from a cohort of pediatric patients who had intravenous catheters inserted in the operating room at an academic tertiary care children's hospital from March 2020 to February 2021. We measured associations among patients who were labeled as having difficult vascular access (>2 attempts at access) with demographic, clinical, and hospital factors. Results 12 728 intravenous catheter insertions were analyzed. Multivariable analysis showed significantly higher odds of difficult vascular access with Black non‐Hispanic race (1.43, 95% CI: 1.06–1.93, p = .018), younger age (0.93, 95% CI: 0.89–0.98, p = .005), overweight (1.41, 95% CI: 1.04–1.90, p = .025) and obese body mass index (1.56, 95% 95% CI: 1.12–2.17, p = .008), and American Society of Anesthesiologists physical status III (1.54, 95% CI:1.11–2.13, p = .01). The attending anesthesiologist compared to all other practitioners (certified registered nurse anesthetist: (0.41, 95% CI: 0.31–0.56, p < .001, registered nurse: 0.25, 95% CI: 0.13–0.48, p < .001, trainee: 0.21, 95% CI: 0.17–0.28, p‐value <.001 with attending as reference variable) and ultrasound use (2.61, 95% CI: 1.85–3.69, p < .001) were associated with successful intravenous catheter placement. Conclusions Black non‐Hispanic race/ethnicity, younger age, obese/overweight body mass index, American Society of Anesthesiologists physical status III, and ultrasound were all associated with pediatric difficult vascular access in the operating room.


| INTRODUC TI ON
Intravenous (IV) access is required to safely care for the majority of children undergoing the estimated 6 million pediatric surgical procedures each year in the United States. 1 Intravenous catheter insertion can be challenging in children due to their smaller caliber blood vessels, with reported first attempt success rates between 39-73%. [2][3][4] Children that require more than 2 attempts at IV access are labeled as difficult venous access (DVA). 5 Most of the literature on children with DVA has originated from the care provided in the Emergency Department (ED) 5,6 with few studies on children undergoing procedures in the operating room (OR). 2,[7][8][9][10] In the OR environment, most children are fasting but are also often anesthetized with anesthetic gases before IV catheter placement, potentially improving insertion through immobilization and venodilation. But this also results in a critical patient safety period where children are prone to hypotension and airway obstruction without IV access. Children with DVA receive delayed care and decreased parental satisfaction with their child's care team. 5,11 Previously reported risk factors for DVA in children include age less than 1 year old, female sex, darker skin color, Black race, obesity, prematurity, end stage renal disease, congenital heart disease, higher American Society of Anesthesiology (ASA) physical status, and emergency surgery. 2,[7][8][9][10][12][13][14] However, these studies have not accounted for the use of ultrasound in obtaining vascular access and its association with DVA. Ultrasound-guided intravenous catheter insertion (USGIV) is a relatively new technique that has been shown to increase success rates and decrease time to cannulation in pediatric patients with DVA. [15][16][17] The use of ultrasound may be helpful in patients with nonvisible veins due to the DVA risk factors of obesity or dark skin color; early application of USGIV might lead to reduction of DVA in these patients. 18,19 The primary aim of the study was to identify factors associated with pediatric DVA in the OR. Our primary hypothesis was that Black race, Hispanic ethnicity, and ultrasound use would be associated with pediatric DVA because Black and Hispanic patients could have darker skin tones making vein visualization more difficult or because previous research has shown healthcare disparities in these groups. 9,[20][21][22] Ultrasound was expected to be associated with DVA because it is often used as a rescue method in our institution after the surface landmark technique has failed.

| Study design & setting
We conducted a retrospective analysis of prospectively collected data from a cohort of all pediatric patients who had an IV cath-

What this article adds
Black non-Hispanic race, younger age, overweight and obese body mass index, American Society of Anesthesiologists physical status III, and ultrasound were associated with pediatric difficult vascular access in the operating room. In patients with difficult intravenous access, the attending anesthesiologist inserting the intravenous catheter was more likely to be successful.

| Procedure
All patients who underwent IV insertion in the OR were evaluated through a query searching for an IV catheter insertion note in the electronic medical record (EMR), Epic (Verona, WI). Information was extracted from the note about the number of IV attempts, practitioner placing the IV, and use of ultrasound. At the study institution, it is routine practice to document this information for every IV inserted in the operating room. The EMR was also queried for each patients' demographic variables [self-reported race/ethnicity, age, sex, weight, and body mass index (BMI)], comorbidities (presence of renal disease, cardiac disease, prematurity, and ASA status), and hospital variables (practitioner type inserting the IV, ultrasound use, inpatient vs. outpatient status, emergency vs. elective surgery, and surgical subspecialty performing the operation).

| Data sources/measurement
We defined difficult vascular access as more than 2 attempts at peripheral IV catheter insertion as has been done in prior studies. 3,6,7,16 Race and ethnicity were modeled as White non-Hispanic, Black non-Hispanic, or White Hispanic. Other racial and ethnic groups were excluded from the analysis due to the small numbers (<5%) of each of these groups.
BMI percentiles were measured using the Centers of Disease Control and Prevention BMI percentile calculator. 24 After converting these BMI percentiles, the values were separated into four categories: underweight (<5th percentile), healthy weight (5 to <85th percentile, overweight (85th to <95th percentile), and obese (>95th percentile). 25 As there are no established norms for BMI in patients who are less than 2 years old, BMI percentiles could not be calculated for these patients.

| RE SULTS
A total of 13 110 IV catheter insertions were completed by anesthesia practitioners during the study period. Three hundred twentynine insertions were excluded due to IV insertion outside of the OR (n = 329) or due to missing data on number of IV attempts (n = 53) in the procedure note, for a total of 12 728 IV placements included in the analysis ( Figure 1). The first attempt success rate was 78.0%.
The results of the univariable logistic regression are shown in were significantly more likely to be associated with ultrasound use. Ultrasound use was strongly associated with DVA in our study.

| DISCUSS ION
In our institution, ultrasound use is a limited resource, so preference is often given to patients with known or predicted difficult access.
Since it is often used as a rescue method after patients have failed institution, many attending anesthesiologists will take over attempts at IV insertion after another practitioner fails twice. We believe this institutional practice is the reason that attendings anesthesiologists were associated with DVA, but we cannot predict this with certainty because only the practitioner associated with the successful attempt was documented in the IV procedure note. However, in contrast, Cuper and colleagues found that attending anesthesiologists were less likely to have first attempt success than anesthetic nurses, postulating that the anesthetic nurses' high skill and long period of practical experience explained the difference. 2 There were several limitations of this study. First, we were unable to determine causation due to the observational nature of this study.
Second, this study took place at a tertiary care children's hospital, so it is unknown our findings are generalizable to other institutions.
Third, the number of IV attempts was self-reported in the medical record; therefore, it is possible that some patients were misclassified as having DVA. Third, we did not adjust for fasting status as a factor for difficult vascular access; however, Galvez did not find an association between fasting status and multiple IV insertions. 9 Fourth, presence of patient comorbidities (prematurity, congenital heart disease, and renal disease) were based on ICD-9/10-CM billing codes associated with the patient's medical record so there is a chance of misclassification bias. 26 Fifth, only the method used for the successful IV attempt is documented in our EMR. We were unable to determine whether ultrasound or landmark techniques were used for previous IV attempts.
Finally, we were unable to determine whether inhalation induction was used before IV catheter insertion because IV insertion documentation occurs after induction and the timestamp of the IV procedure note is the only way we can determine IV insertion time. However, most anesthesiologists would agree that it is more demanding to cannulate a vein in an awake and moving child.
In conclusion, DVA in the operating room was associated with non-Hispanic Black race, younger age, higher BMI, and higher ASA physical status. Patients who experienced DVA in the OR were more likely to have had ultrasound utilized and the attending anesthesiologist inserting the successful IV catheter. Further prospective studies are needed to determine if prediction rules can be developed to guide practice in the operating room.

ACK N OWLED G M ENTS
The

CO N FLI C T O F I NTE R E S T
None.

AUTH O R CO NTR I B UTI O N S
HB helped with the design of the study, analysis and interpretation of data, and drafting the manuscript. JH helped with the acquisition and analysis of data and revising the manuscript. EC helped with the interpretation of the data and revising the manuscript. MK helped with the conception and design of the study, interpretation of data, and revising the manuscript. JB helped with the analysis and interpretation of the data and revising the manuscript. All the authors above approved of the final version of the manuscript and are accountable for all aspects of this work.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from