The anatomic relationship of femoral vein to femoral artery in euvolemic pediatric patients by ultrasonography: implications for pediatric femoral central venous access

Common femoral arterial access and arteriography in infants: Principles, pearls, and pitfalls

Infant femoral arterial access is an essential part of interventional procedures, hemodynamic monitoring, and support of critically ill patients. Due to small luminal diameter, superficial location, mobility, and increased risk of vasospasm, dissection, and thrombosis, femoral artery access in the infant is a technically demanding procedure. The purpose of this manuscript is to describe an approach to successful common femoral arterial access and arteriography in infants including common pearls and pitfalls.

Near zero vascular complications using echo-guided puncture during catheter ablation of arrhythmias: A retrospective study and literature review

Background

Catheter ablation (CA) is routinely used for the treatment of arrhythmias. Vascular complications are the most common complications during these procedures. Previous data reported that ultrasound (US)-guided puncture is a useful method to avoid vascular complications. We reported our experience using US-guided puncture in patients undergoing CA for arrhythmias.

Methods

A total of 273 patients (mean age 57 ± 17 years; 58% male) were referred to our center for CA of arrhythmias from January 2016 to December 2019. All procedures were performed by expert operators, and US-guided vascular access was performed on all patients. Doppler sonography was performed the day after the procedure on all patients.

Results

Eighty-four patients (31%) underwent atrioventricular nodal reentrant tachycardia ablation, 49 patients (18%) atrioventricular reentrant tachycardia ablation, 14 patients (5%) atrial tachycardia ablation, 25 patients (9%) atrial flutter ablation, 63 patients (23%) atrial fibrillation ablation, and 38 patients (14%) ventricular tachycardia ablation. Vascular pseudo-aneurysms and arteriovenous fistula were defined as major complications; furthermore, venous thrombosis and inguinal hematomas were as defined minor complications. The percentage of major vascular complications was 0.3% (1 arteriovenous fistula) and the percentage of minor vascular complications was 0.3% (1 venous thrombosis).

Discussion

Ultrasound-guided vascular puncture in patients undergoing CA is useful to improve procedural success and reduce complications.

Point-of-Care Ultrasound for Central Venous Assessment in the Emergency Department: A Prospective Study Comparing the Femoral and Internal Jugular Veins

OBJECTIVES

The objective of this study was to estimate the width, height, and depth of the femoral vein (FV) and internal jugular vein (IJV), both sites of potential central line placement in children, using point-of-care ultrasound.

METHODS

This was a prospective observational study. Point-of-care ultrasound was used to measure the width, height, and depth of the right FV and IJV in 100 children. The primary outcome was a comparison of the widths of the FV and the IJV in the same child. Our primary hypothesis was that the IJV would be wider than the FV. Secondary outcome measures included comparison of the heights and depths the FV and IJV and description of vessel overlap frequency between the 2 sites.

RESULTS

A total of 106 children were enrolled, with 6 subjects excluded, and equally divided into 5 age groups (0-30 days, 1-24 months, 2-5 years, 6-11 years, and 12-17 years). The FV/IJV width ratios (95% confidence interval) by age were 0.58 (0.49-0.68), 0.53 (0.43-0.66), 0.57 (0.49-0.67), 0.68 (0.55-0.85), and 0.73 (0.62-0.85), all P < 0.002. The FV/IJV height ratios were <1 in all age groups, with P < 0.003 in the 4 youngest age groups. The FV/IJV depth ratios were >1 in 6 to 11 years (P = 0.018) and 12 to 17 years (P < 0.001).

CONCLUSIONS

The IJV was significantly wider and taller than the FV in the same child in all age groups. The FV was significantly deeper than the IJV in children 6 years and older. This supports the use of the IJV as a potential site when placing ultrasound-guided central lines in children.

Iatrogenic vascular trauma and complications of vascular access in children

Vascular access is frequently a critical component of the diagnostic and therapeutic procedures required to manage childhood illnesses, including many emergent conditions and critical illnesses. Vascular access in the pediatric population presents unique challenges, and many clinical and technical factors must be considered to avoid complications that can occur with vascular access procedures. This article reviews various aspects of vascular access and associated iatrogenic trauma in children, including risk factors, management of complications, and preventive measures to avoid complications. It is only with a comprehensive understanding of the topic that vascular access in children can be performed safely, effectively, and efficiently.

Ultrasonographic measurements of femoral vessel diameter in neonates weighing less than 2.5 kg

BACKGROUND

Cannulation in low birth weight (LBW) neonates using larger sheaths could increase the risk of vascular injury. This study investigated the relationship between body weight (BW) and diameter of femoral vessels in LBW neonates and whether BW can be used to predict femoral vessel diameter.

METHODS

The cohort included 100 neonates weighing < 2.5 kg (.57-2.42 kg) with a gestational age of 24-39 weeks. Vascular ultrasonography was used to measure diameters of the bilateral femoral arteries (FA) and veins (FV). The cohort was divided into four groups according to weight: group-A, 2-2.49 kg (n = 28); group-B, 1.5-1.99 kg (n = 38); group-C, 1-1.49 kg (n = 21); and group-D, < 1 kg (n = 13); or according to BSA: group-A, BSA > .16 m² (n = 25); group-B, .13-.16 m² (n = 40); group-C, .1-.13 m² (n = 22); and group-D, < .1 m² (n = 13).

RESULTS

The median vessel diameters (mm) in groups A-D according to weight were FA, 1.96, 1.86, 1.78, and 1.53, and FV, 2.30, 2.28, 2.13, and 1.87, respectively. The median vessel diameters (mm) in groups A-D according to BSA were FA, 1.96, 1.86, 1.76, and 1.53, and FV, 2.30, 2.28, 2.05, and 1.87, respectively. There were positive correlations between BW and femoral vessel diameter (correlation coefficient: .56 and .55 between BW and FA and FV, respectively) (p < 0.001), and between BSA and femoral vessel diameter (correlation coefficient: .56 and .55 between BSA and FA and FV, respectively) (p < 0.001).

CONCLUSIONS

BW is a predictor of femoral vessel diameter in LBW newborns. This finding may help to avoid using larger sheath in smaller vessels.

Angiography in pediatric patients: Measurement and estimation of femoral vessel diameter

The diameter of femoral vessels was angiographically explored in pediatric patients with congenital heart disease (CHD) and compared with anthropometric and demographic indexes.A total of 153 pediatric patients younger than 3 years old were recruited. The sex, age, weight, and height of patients were recorded daily, and the body surface area (BSA) was calculated with the Mosteller formula.The values of mean left-right diameters were 3.13 (0.32) mm for the femoral artery (FA) and 5.14 (0.68) mm for the femoral vein (FV). The FA diameter (FA-Dm) and FV diameter (FV-Dm) were clearly related (R = 0.84, P < .001), and the FA-Dm/FV-Dm ratio ranged from 0.61 to 0.622. The diameters of femoral vessels were significantly correlated with age, height, weight and BSA (R = 0.63 to 0.73, P < .001). The FA-Dm and FV-Dm were most closely associated with the height of patients (FA-Dm: R = 0.73, P < .001; FV-Dm: R = 0.69, P < .001).The FV-Dm and FA-Dm were consistent with the weight, height, age and BSA in the surveyed pediatric patients. The FA-Dm and FV-Dm were closely associated with the height of pediatric patients. Furthermore, the FA-Dm/FV-Dm ratio was stable in these patients. Such estimations could help clinicians select the appropriate diameter of cannulation needles and catheters for interventional therapy pediatric patients with CHD.

Effects of vascular morphological features and ultrasound-guided vascular cannulation techniques on the success of femoral artery catheterisation in newborns

Ultrasound-guided vascular access is a technique that can increase safety as well as technical and procedural success when performing invasive cardiovascular procedures. The aim of this study was to evaluate the effects of two cannulation techniques and vascular morphological properties on the success of femoral artery catheterisation in neonatal patients. We recruited 65 consecutive patients requiring femoral artery catheterisation and randomly divided them into two groups: Group 1, in-plane technique (n = 31) and Group 2, out-of-plane technique (n = 34). We compared the preparation duration, puncture duration, number of punctures, number of arterial punctures, number of unsuccessful interventions, hematoma incidence and vascular morphological characteristics between the groups. The mean age of Group 1 was 17.16 ± 7.04 days, and the mean age of Group 2 was 17.20 ± 7.40 days, with no difference observed between the groups (p > 0.05). Four patients in Group 1 and nine patients in Group 2 developed hematoma (p = 0.172). Hematoma was strongly correlated with the number of venous punctures (r = 0.632; p = 0.001) and the number of needle advancements (r = 0.415; p = 0.001). In terms of artery-vein position, patients whose artery overlapped the vein by > 50% required clearly longer artery cannulation durations than the other patients (p < 0.001). Although the in-plane technique has a steep learning curve, it was found superior in terms of procedure-related factors such as the number of trials, the incidence of hematoma and arterial puncture counts, as it offers advantages such as the ability to evaluate the lumen and a better control of the needle advancement direction.

Symptomatic catheter-associated thrombosis in pediatric trauma patients: Choose your access wisely

BACKGROUND

Traumatic injury and the presence of a central venous catheter are 2 of the strongest risk factors for venous thromboembolism in children. The purpose of this study was to determine the incidence of symptomatic, catheter-associated thrombosis in critically injured children. We hypothesized that femoral venous catheters are associated with a greater rate of thrombotic complications when compared with all other central venous access points.

METHODS

We reviewed a retrospective cohort (2006-2016) of injured children (≤18 years) admitted to a pediatric intensive care unit with central access placed ≤7 days from admission. Symptomatic, catheter-associated thrombosis was determined by radiographic evidence. Poisson regression was used to compare the incidence of catheter-associated thrombosis per 1,000 catheter days between femoral and nonfemoral catheters. All comparisons were 2-tailed with α = 0.05.

RESULTS

We examined 209 pediatric trauma patients with central access (65% femoral, 19% subclavian, 11% arm vein, and 5% internal jugular). Femoral catheters were removed earlier (median [interquartile range] 4 [2-7] vs 8 [3-12] days, P < .001) and were larger in diameter (5 Fr [4-7] vs 4 Fr [4-4], P < .001) when compared with all other catheters. Catheter-associated thrombosis was more frequent in femoral versus nonfemoral catheters (18.4 vs 3.5 per 1,000 catheter days, P = .01).

CONCLUSION

Femoral venous catheters are associated with a greater incidence of symptomatic, catheter-associated thrombosis in pediatric trauma patients. When central venous access is indicated for injured children, the femoral site should be avoided. If a femoral venous catheter is necessary, use of a smaller catheter should be considered.

Ultrasound Guidance for Central Venous Access: Current Evidence and Clinical Recommendations

Ultrasound-guided central line placement has been shown to decrease the number of needle puncture attempts, complication, and failure rates. In order to obtain successful central access, it is important to have adequate cognitive knowledge, workflow understanding, and manual dexterity to safely execute this invasive procedure. The operator should also be familiar with the anatomical variations, equipment operations, and potential complications and their prevention. In this article, we present a detailed review of ultrasound-guided central venous access. It includes a description of anatomy, operative technique, equipment operation, and techniques for specific situations. We describe the use of ultrasound guidance to avoid and identify various complications associated with this procedure. We have also reviewed recent recommendations and guidelines for the use of ultrasound for central venous access and the current evidence pertaining to the recommendations for the expected level of training, methodology, and metrics for establishing competency.

The angle range of leg abduction with external hip rotation which can minimize femoral artery and vein overlap in pediatric patients

BACKGROUND

Since the femoral artery frequently overlaps the femoral vein, femoral central venous catheterization carries the risk of arterial puncture in pediatric patients.

AIMS

We evaluated the angle range of leg abduction with external hip rotation to minimize the overlap between the femoral artery and vein in pediatric patients undergoing general anesthesia.

METHODS

Eighty-two pediatric patients who underwent elective surgery with general anesthesia were enrolled in this study. Using ultrasonography, patients were divided into groups N (patients with non-overlap) and O (patients with continuing overlap) based on the presence of non-overlap range between the femoral artery and vein. The range minimizing the overlap was defined as the range without overlap in group N and as the range presenting the overlap that was less-than-half of the radius of the femoral vein in group O. By increasing the angle of leg abduction with external hip rotation, the starting and ending angles minimizing the overlap were found using ultrasonographic images.

RESULTS

The angle range of leg abduction with external hip rotation minimizing the overlap between the femoral artery and vein was defined as the range from the maximum 99% confidence interval of starting angles to the minimum 99% confidence interval of ending angles, which was between 45° and 65° in group N and between 48° and 58° in group O, respectively.

CONCLUSION

Positioning patients in a range of 48° and 58° leg abduction with external hip rotation can minimize the overlap between the femoral artery and vein. However, the clinical usefulness of this positioning for femoral venous catheterization remains to be seen.

Vascular ultrasound in pediatrics: utility and application of location and measurement of jugular and femoral vessels

OBJECTIVE

To measure the depth (D _p) and diameter (D _m) of the internal jugular vein (IJV), femoral vein (FV), and femoral artery (FA) in pediatric patients to evaluate the clinical implications.

METHODS

This study included 125 pediatric patients. All of them underwent bilateral ultrasound study of vessels and were classified into three groups based on anthropometric and demographic parameters.

RESULTS

Measured mean D _p values were: 0.72 (0.34) cm for the FA, 0.79 (0.35) cm for the FV, and 0.77 (0.24) cm for the IJV. Mean antero-posterior D _m values were: 0.37 (0.17) cm for the FA, 0.42 (0.22) cm for the FV, and 0.59 (0.23) cm for the IJV. D _p and D _m increased with age (A), weight (W), height (H), and body surface area (BSA). In the lower ranges of these variables, D _p was similar for all three studied vessels (0.6-0.7 cm). In the higher ranges, femoral vessel D _p values (1.1-1.2 cm) were larger than jugular ones (0.9 cm). Additionally, in these low ranges, IJV D _m values were larger than femoral ones (0.45-0.50 vs. 0.25 cm). In the higher ranges, diameter values were similar (0.6-0.7 cm).

CONCLUSIONS

In pediatric patients, major vessels can be located and their depth and diameter measured by vascular ultrasound. In younger patients, jugular and femoral vessels had similar depth values; in older ones, they had similar diameters. Ultrasound measurements in pediatric patients could facilitate the choice of the vessel to be cannulated, the catheter diameter, and the length of the needle to be used. Vascular canalization of IJV may be recommended as the first choice because of its low depth and large diameter.

Vascular ultrasound in pediatrics: estimation of depth and diameter of jugular and femoral vessels

Objectives

To estimate, on the basis of anthropometric and demographic variables, the depth (Dp) and diameter (Dm) of femoral and jugular vessels, which have been located and measured by ultrasound, in pediatric patients.

Method

750 measurements of Dp and Dm of the femoral vein (FV), femoral artery (FA) and internal jugular vein (IJV) were made in 125 pediatric patients. The values were correlated with patients' sex, weight, age, size and body surface area (BSA).

Results

Mean Dp values were 0.72 (0.34) cm for FA, 0.79 (0.35) cm for FV and 0.77 (0.24) cm for IJV. Mean antero-posterior Dm values were 0.37 (0.17) cm for FA, 0.42 (0.22) cm for FV and 0.59 (0.23) cm for IJV. In the studied pediatric patients, femoral and jugular vessels depth correlated with age, size, weight and BSA (R = 0.46-0.60); vascular depth could be estimated from patients' weight and size (FA-Dp: R = 0.71; FV-Dp: R = 0.72; IJV-Dp: R = 0.53). Correlation with diameter was better for FA and FV (R = 0.81-0.89) than for IJV (R = 0.42-0.51); vascular diameter could be estimated from patient's size (FA-Dm: R = 0.89; FV-Dm: R = 0.86; IJV-Dm: R = 0.52).

Conclusions

FV, FA and IJV depth and diameter correlated with weight, size, age and body surface area in the studied pediatric patients. Correlation was better for femoral than for jugular vessels. Depth could be estimated from patients' weight and size, while diameter could be estimated from the size. Such estimations may facilitate the choice of vessels to be cannulated, length and diameter of cannulation needles and the diameter of catheters to be used in pediatric patients.

A hand-held robotic device for peripheral intravenous catheterization

Intravenous catheterization is frequently required for numerous medical treatments. However, this process is characterized by a high failure rate, especially when performed on difficult patients such as newborns and infants. Very young patients have small veins, and that increases the chances of accidentally puncturing the catheterization needle directly through them. In this article, we present the design, development and experimental evaluation of a novel hand-held robotic device for improving the process of peripheral intravenous catheterization by facilitating the needle insertion procedure. To our knowledge, this design is the first hand-held robotic device for assisting in the catheterization insertion task. Compared to the other available technologies, it has several unique advantages such as being compact, low-cost and able to reliably detect venipuncture. The system is equipped with an electrical impedance sensor at the tip of the catheterization needle, which provides real-time measurements used to supervise and control the catheter insertion process. This allows the robotic system to precisely position the needle within the lumen of the target vein, leading to enhanced catheterization success rate. Experiments conducted to evaluate the device demonstrated that it is also effective to deskill the task. Naïve subjects achieved an average catheterization success rate of 88% on a 1.5 mm phantom vessel with the robotic device versus 12% with the traditional unassisted system. The results of this work prove the feasibility of a hand-held assistive robotic device for intravenous catheterization and show that such device has the potential to greatly improve the success rate of these difficult operations.

Utility of Ultrasound Guidance for Central Venous Access in Children

BACKGROUND

Placement of a central venous catheter (CVC) in a pediatric patient is an important skill for pediatric emergency medicine physicians but can be challenging and time consuming. Ultrasound (US) guidance has been shown to improve success of central line placement in adult patients.

OBJECTIVES

This article aims to review the literature and evaluate the benefit of US guidance in the placement of CVCs, specifically in pediatric emergency department patients, and to review the procedure.

RESULTS

Four meta-analyses of US-guided CVC placement in adult patients concluded that US guidance reduces placement failure, decreases complications, and decreases the need for multiple attempts. Two studies in the emergency department setting support these conclusions. Pediatric-specific data related to US-guided CVC placement include data suggesting a benefit with US guidance, as well as data indicating no difference in outcome measures when US guidance is used compared with the landmark technique.

CONCLUSIONS

The evidence surrounding US-guided CVC insertion supports its use in adult patients. Pediatric-specific literature is sparse and includes mixed results. As more pediatric emergency physicians adopt the use of point-of-care US, we expect an increase in data supporting its use for CVC placement in pediatric emergency department patients.

Pediatric emergency medicine point-of-care ultrasound: summary of the evidence

The utility of point-of-care ultrasound is well supported by the medical literature. Consequently, pediatric emergency medicine providers have embraced this technology in everyday practice. Recently, the American Academy of Pediatrics published a policy statement endorsing the use of point-of-care ultrasound by pediatric emergency medicine providers.  To date, there is no standard guideline for the practice of point-of-care ultrasound for this specialty. This document serves as an initial step in the detailed "how to" and description of individual point-of-care ultrasound examinations.  Pediatric emergency medicine providers should refer to this paper as reference for published research, objectives for learners, and standardized reporting guidelines.

The relative position of femoral artery and vein in children under general anesthesia--an ultrasound-guided observational study

BACKGROUND

Femoral artery overlaps femoral vein by varying degrees distal to the inguinal ligament, which may result in difficult venous access and also increases the risk of arterial puncture.

OBJECTIVE

To study the size of femoral vessels and the degree of overlap in children undergoing anesthesia using ultrasound at 1 and 3 cm distal to inguinal ligament.

METHODS

A prospective observational study, 84 children aged <7 years were recruited in six different age groups. An experienced anesthetist identified the femoral vessels and their overlap using ultrasound at two fixed points distal to the inguinal ligament. We also evaluated the correlation of skin puncture site marked as per Advanced Paediatric Life support (APLS) guidance using landmark technique with the ultrasound location of femoral vein beneath the same site.

RESULTS

The percentage of children with overlap of femoral vein by femoral artery increases from 5% to 60% as we move distal to the inguinal ligament. At 3 cm distal to inguinal ligament, the incidence of any degree of overlap was statistically significant (P < 0.05) in children <5 years. In 80% of children, the femoral vein was located by ultrasound beneath the skin puncture site as recommended by APLS guidelines.

CONCLUSION

A significant increase in femoral vein overlap occurs as we move distal to the inguinal ligament. There is one in five chance of failure to locate femoral vein by landmark technique. In children <2 years, a high approach to femoral vein cannulation under ultrasound guidance is recommended.

Ultrasonographic anatomic variations of the major veins in paediatric patients

BACKGROUND

The aim of our study was to describe the anatomic relationships in internal jugular (IJV), subclavian (SCV), and femoral (FV) vein sites.

METHODS

One hundred and forty-two children had a two-dimensional (2D) ultrasound (US) evaluation of IJV, SCV, and FV sites. They were enrolled according to their age: 0-1 month old (n=9), 1 month old to 2 yr old (n=61), 2-6 yr old (n=22), 6-12 yr old (n=32), and 12-18 yr old (n=18).

RESULTS

We found about 7.7% variation for the IJV. The most common anatomic variations were a lateral (nine children) or anterior (nine children) position of the IJV to the carotid artery. Regardless of the age category, about 9.8% of the anatomic variations were found for the FV. The most common anatomic variation in our study was that the FV ran anteromedially to the femoral artery (17 children). Anatomic variation of the SCV, regardless of age category, was about 7.4%. The most common anatomic variation was the SCV, which ran medially (10 children) to the subclavian artery.

CONCLUSIONS

The relevant percentages of anatomic variations obtained for all these areas support at least a systematic US screening before attempting to obtain central venous access, ideally using a US-guided technique.

Development and evaluation of a program for the use of ultrasound for central venous catheter placement in a pediatric emergency department

BACKGROUND

A growing body of literature supports the use of ultrasound (US) to assist central venous catheter (CVC) placement, and in many settings, this has become the standard of care. However, this remains a relatively new and uncommonly performed procedure for pediatric emergency medicine physicians.

OBJECTIVES

This study aims to describe the change over time in percentage of CVC procedures performed with US assistance per 10,000 patient visits in a pediatric emergency department.

METHODS

We describe the development of an emergency US program in a pediatric emergency department and investigate how US use for CVC placement in internal jugular and femoral veins changed from July 2007, when US became available, until December 2011. Data related to CVC procedures were obtained from a procedure database maintained for quality assurance purposes.

RESULTS

The percentage of CVC procedures performed with US assistance increased significantly over time (P < 0.001).

CONCLUSIONS

The development of an emergency US program was associated with significantly increased physician use of US for CVC placement.

Left femoral vein is a better choice for cannulation in children: a computed tomography study

BACKGROUND

Central venous catheters are often required in emergency rooms and intensive care and/or those undergoing major surgical procedures. In this study, we aimed to gain a better understanding of the anatomy of the femoral vessel in relation to central venous cannulation.

METHODS

The right and left (total of 180) femoral veins (FVs) of 90 consecutive pediatric patients were retrospectively evaluated using computed tomography images. Patients were divided into two groups according to their age: group 1, patients up to 9 years of age; and group 2, patients between 9 and 16 years of age.

RESULTS

The position and overlap of femoral artery (FA) to FV are significantly different between the left and right sides in both groups (P = 0.001). The left FV was most commonly located medial to the FA. However, the right FV was most commonly located posterior-medial to the FA. The incidence of overlap of the FA over the FV was significantly lower at the left side in both groups.

CONCLUSION

The incidence of overlap of the FA over the FV was significantly lower at the left side in pediatric patients. This finding was similar between the patients aged 2-8 years and those aged 9-16 years and may have significant clinical implications. Guiding clinicians to select the left FV of children for cannulation may result in lower arterial puncture rates while accessing the central vein.

Minimizing complications associated with percutaneous central venous catheter placement in children: recent advances

OBJECTIVES

To summarize existing knowledge regarding the prevalence of complications associated with temporary percutaneous central venous catheters placed in critically ill children, and to review evolving strategies to minimize the prevalence of these complications.

DATA SOURCES

Literature review was performed: PubMed and EBSCOhost were searched using the terms central venous catheter, children, ultrasound, infection, thrombosis, and thromboembolism in various combinations. Citations of interest from identified articles were also reviewed.

STUDY SELECTION

The review focused primarily on pediatric literature relevant to the topic of interest.

DATA EXTRACTION AND SYNTHESIS

Randomized clinical trials and other prospective studies were discussed in greater detail than retrospective, single-center investigations.

CONCLUSIONS

Complications during percutaneous central venous catheter placement in children are not rare and may be in part attributable to abnormalities in vascular anatomy. Thromboses in children with central venous catheters are increasingly recognized as an important problem for which evidence-based preventive measures are lacking. Catheter-associated bloodstream infection rates in critically ill children have markedly decreased over the last decade, associated with an increased emphasis on staff education and the use of insertion and maintenance bundles. Available evidence tends to support the use of two-dimensional ultrasound to augment the landmark technique for catheter placement, but more studies are needed.

Greater saphenous vein location in a pediatric population

The purpose of this study was to assess the accuracy of a landmark technique for cannulation of the greater saphenous vein (GSV) near the medial malleolus. We performed bedside ultrasound in a convenience sample of 100 children, ages 3 to 16 years, to evaluate the anatomy of the GSV at the ankle. Despite the proposed constancy of the landmark technique regardless of patient age, the GSV location varied significantly with increasing patient age and weight. In children less than 10 years old or weighing less than 40 kg, the traditional landmark rarely predicted the precise location of the GSV.

Ultrasound-guided femoral vein catheterization in neonates with cardiac disease*

OBJECTIVE

To describe a novel technique for real-time, ultrasound-guided femoral vein catheterization in neonates with cardiac disease, and to compare it to a contemporaneous cohort of neonates undergoing femoral vein central venous line placement via landmark technique.

DESIGN

Retrospective cohort study of data extracted from a quality improvement database.

SETTING

Pediatric cardiac intensive care unit and cardiovascular operating room in pediatric tertiary hospital.

PATIENTS

One hundred fifteen neonates (mean weight, 3.07 ± 0.41 kg) with cardiac disease who underwent femoral central venous line attempts from January 2009 to September 2011.

MEASUREMENTS AND MAIN RESULTS

Study populations were similar in age, weight, and Risk Adjustment for Congenital Heart Surgery-1 category, but differed in intubation status (32% vs. 100%, ultrasound vs. landmark, p < .0001). Central venous line success rate was superior in the ultrasound group: 72 of the 76 (94.7%) vs. 31 of the 39 (79.5%), p = .02. Ultrasound group also had a superior first (75% vs. 30.8 %) and second attempt success rate (90.8% vs. 51.3%), p value for both < .0001. Inadvertent arterial puncture occurred less frequently in the ultrasound group: four of the 76 (5.3%) vs. nine of the 39 (23.1%), p = .01. There was a trend toward more venous thrombosis in the landmark group, 16 of the 39 (41%) vs. 18 of the 76 (23.7%), p = .08. Among all 115 subjects, there was a very strong association between greater than two central venous line attempts and the odds of being diagnosed with a deep venous thrombosis (odds ratio, 9.3; 95% confidence interval 3.5-24.8) and the odds of suffering an inadvertent femoral arterial puncture during the central venous line event (odds ratio, 8.8; 95% confidence interval 10.6-730).

CONCLUSIONS

This novel long-axis real-time ultrasound technique facilitates placement of femoral vein central venous line in critically ill neonates with cardiac disease at a higher rate of success with fewer attempts and lower occurrence of complications when compared with the landmark technique.

Advanced technologies in trauma critical care management

Care of critically injured patients has evolved over the 50 years since Shoemaker established one of the first trauma units at Cook County Hospital in 1962. Modern trauma intensive care units offer a high nurse-to-patient ratio, physicians and midlevel providers who manage the patients, and technologically advanced monitors and therapeutic devices designed to optimize the care of patients. This article describes advances that have transformed trauma critical care, including bedside ultrasonography, novel patient monitoring techniques, extracorporeal support, and negative pressure dressings. It also discusses how to evaluate the safety and efficacy of future advances in trauma critical care.

Dimension and overlap of femoral and neck blood vessels in neonates

INTRODUCTION

Neonates frequently require access to their central blood vessels. However, limited data exist relating to the size and the anatomical relation of the femoral and neck vessels for neonates of different postmenstrual ages.

HYPOTHESIS

1) The size of central blood vessels increases with postmenstrual age of the neonate. 2). External rotation with abduction at the hip will decrease the degree of overlap between the femoral artery and vein. 3) The degree of overlap decreases with increasing postmenstrual age.

DESIGN

Prospective descriptive cohort study.

MEASUREMENTS AND MAIN RESULTS

Femoral and neck vessel sizes were assessed using ultrasound for three postmenstrual age groups: group A (26 ± 1 wks), group B (32 ± 1 wks), and group C (38 ± 1 wks). The degrees of overlap (major, >50% overlap; minor, ≤50% overlap; no overlap) between the femoral vessels were assessed at the level of the inguinal ligament and 1 cm below the inguinal ligament in a straight hip and in external rotation with abduction of the hip positions. A total of 52 nonconsecutive subjects (group A, seven; group B, 21; group C, 24) were studied. The mean blood vessel dimensions increased with increasing postmenstrual age. Correlation of blood vessel size to growth measurements was better in group A + group B compared to group C. Overlap between the femoral vein and the femoral artery across the neonatal age groups at the level of the inguinal ligament ranged from 57% to 79% and from 43% to 98% at 1 cm below the inguinal ligament. The degree of overlap did not decrease with positioning of the lower extremity in external rotation with abduction of the hip. In the neck blood vessels, the majority of observations showed either minor or major overlap of neck blood vessels in all three groups (group A, 79%; group B, 86%; group C, 90%).

CONCLUSIONS

Central blood vessel size increases with increasing postmenstrual age. Correlation of blood vessel size to anthropometric measurements was better in the premature neonates compared to term neonates. A high degree of overlap exists within the femoral and cervical blood vessels. In the femoral vessels, the degree of overlap did not decrease with external rotation with abduction of the hip at any postmenstrual age.

Bedside ultrasonography detects significant femoral vessel overlap: implications for central venous cannulation

OBJECTIVE

Our goal was to gain a better understanding of the femoral vessel anatomy as it relates to central venous cannulation. The primary objective of this study was to use bedside ultrasonography to determine the amount of exposed femoral vein at three sites corresponding to surface anatomy of the landmark-based procedure.

METHODS

This cross-sectional study enrolled a random sample of 180 adult patients presenting to a large urban academic emergency department. Subjects underwent standardized ultrasonography to identify and measure the depth and diameter of the femoral vessels and amount of exposed femoral vein at the level of the inguinal ligament (0 cm) 2 cm and 4 cm below. Repeated measures analysis of variance was used to determine significant relationships between vessel measurements and distance from the inguinal ligament.

RESULTS

The median age was 44.5 (range 19-90) years; 101 patients were male. The mean (± SD) percentage of exposed vein at the inguinal ligament was 83% (± 21). This decreased significantly (p < 0.01) with increasing distance from the inguinal ligament: 65% (± 25) at 2 cm and 56% (± 30) at 4 cm. At every distance away from the inguinal ligament, there were some subjects with no vein exposed.

CONCLUSION

This study demonstrates significant overlap of the femoral vessels at sites where landmark-based femoral vein cannulation is often attempted. Our results suggest that ultrasound guidance would be beneficial as femoral vein cannulation may be difficult or impossible in certain individuals owing to anatomic variations.

The effects of hip abduction with external rotation and reverse Trendelenburg position on the size of the femoral vein; ultrasonographic investigation

Background

Femoral vein (FV) catheterization is required for critically ill patients, patients with difficult peripheral intravenous access, and patients undergoing major surgery. The purpose of this study was to evaluate the effects of hip abduction with external rotation (frog-leg position), and the frog-leg position during the reverse Trendelenburg position on diameter, cross-sectional area (CSA), exposed width and ratio of the FV using ultrasound investigation.

Methods

Ultrasonographic FV images of 50 adult subjects were obtained: 1) in the neutral position (N position); 2) in the frog-leg position (F position); 3) in the F position during the reverse Trendelenburg position (FRT position). Diameter, CSA, and exposed width of the FV were measured. Exposed ratio of the FV was calculated.

Results

The F and FRT positions increased diameter, CSA and exposed width of the FV significantly compared with the N position. However, the F and FRT positions had no significant effect on exposed ratio of the FV compared with the N position. The FRT position was more effective than the F position in increasing FV size.

Conclusions

The F and FRT positions can be used to increase FV size during catheterization. These positions may increase success rate and reduce complication rate and, therefore, can be useful for patients with difficult central venous access or at high-risk of catheter-related complication.

Vascular access in the neonate

Up to recently, inserting venous or arterial 'lines' in the neonate was essentially based on clinical skill and experience. The recent advent of portable ultrasound (US) machines with paediatric probes has resulted in the development of new approaches that, if correctly learned and used, should allow quicker and safer vascular access in this population. Both classic and new techniques are reviewed on the basis of literature and authors' experience.

Femoral vein cannulation performed by residents: a comparison between ultrasound-guided and landmark technique in infants and children undergoing cardiac surgery

BACKGROUND

Percutaneous cannulation of the femoral vein, in the pediatric age group, can be technically challenging, especially when performed by residents in training. We examined whether the use of real-time ultrasound guidance is superior to a landmark technique for femoral vein catheterization in children undergoing heart surgery.

METHODS

Patients were prospectively randomized into 2 groups. In group LM, the femoral vein was cannulated using the traditional method of palpation of arterial pulse. In group US, cannulation was guided by real-time scanning with an ultrasound probe. The time to complete cannulation (primary outcome), success rate, number of needle passes, number of successful cannulations on first needle pass, and incidence of complications were compared between the 2 groups.

RESULTS

Forty-eight pediatric patients were studied. The time to complete cannulation was significantly shorter (155 [46-690] vs 370 [45-1620] seconds; P = 0.02) in group US versus group LM. The success rate was similar in both groups (95.8%). The number of needle passes was smaller (1 [1-8] vs 3 [1-21]; P = 0.001) and the number of successful cannulations on first needle pass higher (18 vs 6; P = 0.001) in group US compared with group LM. The incidence of femoral artery puncture was comparable between the 2 groups.

CONCLUSIONS

Ultrasound-guided cannulation of the femoral vein, in pediatric patients, when performed by senior anesthesia residents, is superior to the landmark technique in terms of speed and number of needle passes, with remarkable improvement in first attempt success.

Video analysis of accidental arterial cannulation with dynamic ultrasound guidance for central venous access

OBJECTIVE

Accidental arterial cannulation during ultrasound-guided central venous cannulation is rarely reported and should be much less likely with dynamic guidance. Although accidental arterial penetration with the needle may occur periodically without notice and with little harm, actual arterial dilation and line placement may result in serious complications.

METHODS

This series reports 6 such cases of accidental arterial cannulation and central line insertion under dynamic ultrasound guidance.

RESULTS

Two of the arterial cannulations resulted in airway loss, with 1 of these ending in death. The remaining 4 arterial lines led to serious local complications. Ultrasound video analysis of each line placement or postplacement analysis was reviewed, and common pitfalls were extracted. In 3 cases, a central line went directly through the internal jugular vein (IJ) and into the carotid artery. In 1 case, a cordis introducer sheath traveled through the posterior wall of the common femoral vein and into the deep femoral artery branch below. Each patient was hypotensive and hypoxic, making traditional safety checkpoints such as aspiration of bright red blood and pulsatile flow from the syringe hub less reliable in identifying accidental arterial cannulation. All ultrasound-guided cannulations were performed by a standard short-axis approach with high-resolution linear array ultrasound transducers on modern equipment.

CONCLUSIONS

The short-axis approach, as seen in this series, can provide a false sense of security to the practitioner and allows for potentially dangerous accidental arterial cannulation. In the setting of critically ill patients, it may be prudent to not only visualize the entire path of the needle with the long-axis approach but also confirm correct cannulation by tracing the guide wire in the long axis before line placement.

The anatomic relationship between the common femoral artery and common femoral vein in frog leg position versus straight leg position in pediatric patients

BACKGROUND

Overlap of the femoral artery (FA) on the femoral vein (FV) has been shown to occur in pediatric patients. This overlap may increase complications such as arterial puncture and failed insertions of central venous lines (CVLs). Knowledge of the anatomic relationship between the FV and FA may be important in avoiding these complications.

OBJECTIVES

The objective was to evaluate the anatomic relationship of the FA and FV in straight leg position and frog leg position.

METHODS

This was a prospective, descriptive study of a convenience sample of 80 total subjects (16 subjects from each of five predetermined stratified age groups). Each subject underwent a standardized ultrasound examination in both the straight and the frog leg positions. The location of the FA in relation to the FV was measured at three locations: immediately distal, 1 cm distal, and 3 cm distal to the inguinal ligament. Overlap of the FA on the FV and the diameter of the FV was noted at each location. Measurements were repeated in both the straight leg and the frog leg positions.

RESULTS

For the left leg, immediately distal to the inguinal ligament, the FV was overlapped by the FA in 36% of patients in straight leg position and by 45% of patients in frog leg position. At 1 cm distal to the ligament, overlap was observed in 75% of patients in straight leg position and 88% of patients in the frog leg position. At 3 cm distal to the ligament, overlap was observed in 93% of patients in straight leg position and 86% of patients in the frog leg position. The percentage of vessels with overlap was similar in the right leg at each location for both the straight and the frog leg positions. Pooled mean (+/-SD) FV diameters for the left leg immediately distal to the inguinal ligament were 0.64 (+/-0.23) cm in the straight leg position and 0.76 (+/-0.28) cm in the frog leg position; at 1 cm distal to the ligament, 0.66 (+/-0.23) and 0.78 (+/-0.29) cm; and at 3 cm distal to the ligament, 0.65 (+/-0.27) and 0.69 (+/-0.29) cm. FV diameters for the right leg were similar to the left.

CONCLUSIONS

A significant percentage of children have FAs that overlap their FVs. This overlap may be responsible for complications such as FA puncture with CVL placement. Ultrasound-guided techniques may decrease these risks. Placing children in the frog leg position increases the diameter of the FV visualized on ultrasound.