Michael Blaivas

International evidence-based recommendations on ultrasound-guided vascular access

PurposeTo provide clinicians with an evidence-based overview of all topics related to ultrasound vascular access.MethodsAn international evidence-based consensus provided definitions and recommendations. Medical literature on ultrasound vascular access was reviewed from January 1985 to October 2010. The GRADE and the GRADE-RAND methods were utilised to develop recommendations.ResultsThe recommendations following the conference suggest the advantage of 2D vascular screening prior to cannulation and that real-time ultrasound needle guidance with an in-plane/long-axis technique optimises the probability of needle placement. Ultrasound guidance can be used not only for central venous cannulation but also in peripheral and arterial cannulation. Ultrasound can be used in order to check for immediate and life-threatening complications as well as the catheter’s tip position. Educational courses and training are required to achieve competence and minimal skills when cannulation is performed with ultrasound guidance. A recommendation to create an ultrasound curriculum on vascular access is proposed. This technique allows the reduction of infectious and mechanical complications.ConclusionsThese definitions and recommendations based on a critical evidence review and expert consensus are proposed to assist clinicians in ultrasound-guided vascular access and as a reference for future clinical research.

An unseen danger: Frequency of posterior vessel wall penetration by needles during attempts to place internal jugular vein central catheters using ultrasound guidance

Objectives:To evaluate the frequency of unsuspected posterior vessel wall penetration of the internal jugular vein during ultrasound-guided needle cannulation. Design:Prospective, single-blinded observational study. Setting:Urban level I emergency department with an annual census of 80,000. Patients:Residents who had previously completed a 2-day ultrasound course including a 3-hr didactic and hands-on session on ultrasound-guided central venous cannulation. Interventions:Residents were asked to place an ultrasound-guided catheter on a human torso mannequin. Residents used a short-axis approach for ultrasound guidance. During the procedure, an 8–4 MHz convex (endocavity) transducer was used to observe the path of the resident’s needle without interference with the placement procedure. Measurements and Main Results:Unknown to residents, researchers tracked the frequency of posterior wall penetration and the final needle location when the resident felt that optimal needle placement was achieved in the lumen of the internal jugular. Residents were also asked to rate their confidence regarding appropriate final needle position on a 10-point Likert scale. Statistical analysis consisted of descriptive statistics and Spearman correlation analysis. A total of 25 residents participated. All had placed at least one ultrasound-guided central catheter previously. The median number of previous ultrasound-guided cannulations was 8.0. Sixteen (64%) residents accidentally penetrated the posterior wall of the internal jugular vein during cannulation. The median number of posterior wall penetrations was 1.0 for all residents. In six cases the final location of the needle was through the posterior wall and deep to the venous lumen. In five of these cases the carotid artery was actually mistakenly penetrated. Median confidence by residents regarding appropriate needle placement was 8.0 out of 10. More training and more ultrasound-guided catheters placed were associated with fewer posterior wall penetrations (p = .04). Conclusions:In this study, residents accidentally penetrated the posterior vessel wall of the internal jugular in a lifelike vascular access mannequin in the majority of cases. These results suggest that care must be taken even with ultrasound-guided central catheter placement and that alternative ultrasound guidance techniques, such as visualization of the vein and needle in longitudinal axis, should be considered.

Guidelines for the Appropriate Use of Bedside General and Cardiac Ultrasonography in the Evaluation of Critically Ill Patients-Part I: General Ultrasonography.

Objective: To establish evidence-based guidelines for the use of bedside ultrasound by intensivists and specialists in the ICU and equivalent care sites for diagnostic and therapeutic purposes for organs of the chest, abdomen, pelvis, neck, and extremities. Methods: The Grading of Recommendations, Assessment, Development and Evaluation system was used to determine the strength of recommendations as either strong or conditional/weak and to rank the “levels” of quality of evidence into high (A), moderate (B), or low (C) and thus generating six “grades” of recommendation (1A-1B-1C-2A-2B-2C). Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for all questions with clinically relevant outcomes. RAND appropriateness method, incorporating modified Delphi technique, was used in steps of GRADE that required panel judgment and for those based purely on expert consensus. The process was conducted by teleconference and electronic-based discussion, following clear rules for establishing consensus and agreement/disagreement. Individual panel members provided full disclosure and were judged to be free of any commercial bias. The process was conducted independent of industry funding. Results: Twenty-four statements regarding the use of ultrasound were considered—three did not achieve agreement and nine were approved as conditional recommendations (strength class 2). The remaining 12 statements were approved as strong recommendations (strength class 1). Each recommendation was also linked to its level of quality of evidence. Key strong recommendations included the use of ultrasonography for ruling-in pleural effusion and assisting its drainage, ascites drainage, ruling-in pneumothorax, central venous cannulation, particularly for internal jugular and femoral sites, and for diagnosis of deep venous thrombosis. Conditional recommendations were given to the use of ultrasound by the intensivist for diagnosis of acalculous cholecystitis, renal failure, and interstitial and parenchymal lung diseases. No recommendations were made regarding static (vs dynamic) ultrasound guidance of vascular access or the use of needle guide devices. Conclusions: There was strong agreement among a large cohort of international experts regarding several recommendations for the use of ultrasound in the ICU. Evidence-based recommendations regarding the appropriate use of this technology are a step toward improving patient outcomes in relevant patients.

Short-axis versus Long-axis Approaches for Teaching Ultrasound-guided Vascular Access on a New Inanimate Model

Objectives: To determine whether a short-axis (SA) or long-axis (LA) ultrasound (US) approach to guidance for line placement results in faster vascular access for novice US users. Also, to assess if there was a difference in the number of skin penetrations and needle redirections between the two guidance techniques. Methods: This was a prospective, randomized, observational study of emergency medicine (EM) residents at a Level I trauma center. A gelatin dessert and dietary fiber supplement mixture, providing a realistic US image, were placed inside a synthetic arm skin that is used for training phlebotomists and contains a rubber vein filled with red fluid at a depth of 1.5 cm. After a 30-minute tutorial on US-guided vascular access, EM residents were randomized to one of two groups. Group one attempted SA first and then the LA. Group two tried LA first followed by the SA. Time from skin break to vein cannulation, number of skin breaks and needle redirections, and difficulty of access on a 10-point Likert scale as reported by residents were recorded. Statistical analysis included paired Students t-test with 95% confidence intervals (95% CIs). Results: Seventeen EM residents participated. The mean times to vein cannulation in SA and LA were 2.36 minutes (95% CI = 1.15 to 3.58) and 5.02 minutes (95% CI = 2.90 to 7.13), respectively (p = 0.03). The mean numbers of skin breaks for SA and LA were 4.18 (95% CI = 1.18 to 7.17) and 5.76 (95% CI = 1.83 to 9.69), respectively (p = 0.49). The mean numbers of needle redirections in the SA and LA were 13.71 (95% CI = 4.51 to 22.89) and 18.17 (95% CI = 7.95 to 28.40), respectively (p = 0.51). The mean difficulty scores for SA and LA were 3.99 (95% CI = 2.42 to 5.67) and 5.86 (95% CI = 4.32 to 7.40), respectively (p = 0.17). Conclusions: Novice US users obtain vascular access faster with an SA approach on an inanimate model.

Needle tip visualization during ultrasound-guided vascular access: short-axis vs long-axis approach.

OBJECTIVES Ultrasound guidance for central venous catheterization improves success rates and decreases complications when compared to the landmark technique. Prior research has demonstrated that arterial and/or posterior vein wall puncture still occurs despite real-time ultrasound guidance. The inability to maintain visualization of the needle tip may contribute to these complications. This study aims to identify whether long-axis or short-axis approaches to ultrasound-guided vascular access afford improved visibility of the needle tip. METHODS A prospective trial was conducted at a level I trauma center with an emergency medicine residency. Medical students and residents placed needles into vascular access tissue phantoms using long-axis and short-axis approaches. Ultrasound images obtained at the time of vessel puncture were then reviewed. Primary outcome measures were visibility of the needle tip at the time of puncture and total time to successful puncture of the vessel. RESULTS All subjects were able to successfully obtain simulated blood from the tissue phantom. Mean time to puncture was 14.8 seconds in the long-axis group and 12.4 seconds in the short-axis group (P = .48). Needle tip visibility at the time of vessel puncture was higher in the long-axis group (24/39, 62%) as opposed to the short-axis group (9/39, 23%) (P = .01). CONCLUSIONS In a simulated vascular access model, the long-axis approach to ultrasound-guided vascular access was associated with improved visibility of the needle tip during vessel puncture. This approach may help decrease complications associated with ultrasound-guided central venous catheterization and should be prospectively evaluated in future studies.

A rapid noninvasive method of detecting elevated intracranial pressure using bedside ocular ultrasound: application to 3 cases of head trauma in the pediatric emergency department.

Abstract: Managing pediatric head trauma with elevated intracranial pressure in the acute setting can be challenging. Bedside ocular ultrasound for measuring optic nerve sheath diameters has been recently proposed as a portable noninvasive method to rapidly detect increased intracranial pressure in emergency department patients with head trauma. Prior study data agree that the upper limit of normal optic nerve sheath diameters is 5.0 mm in adults, 4.5 mm in children aged 1 to 15, and 4.0 mm in infants up to 1 year of age. We report the application of this technique to 3 cases of head trauma in the pediatric emergency department.

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.

A Prospective Comparison of Procedural Sedation and Ultrasound-guided Interscalene Nerve Block for Shoulder Reduction in the Emergency Department

OBJECTIVES Emergency physicians (EPs) are beginning to use ultrasound (US) guidance to perform regional nerve blocks. The primary objective of this study was to compare length of stay (LOS) in patients randomized to US-guided interscalene block or procedural sedation to facilitate reduction of shoulder dislocation in the emergency department (ED). The secondary objectives were to compare one-on-one health care provider time, pain experienced by the patient during reduction, and patient satisfaction between the two groups. METHODS This was a prospective, randomized study of patients presenting to the ED with shoulder dislocation. The study was conducted at an academic Level I trauma center ED with an annual census of approximately 80,000. Patients were eligible for the study if they were at least 18 years of age and required reduction of a shoulder dislocation. A convenience sample of patients was randomized to either traditional procedural sedation or US-guided interscalene nerve block. Procedural sedation was performed with etomidate as the sole agent. Interscalene blocks were performed by hospital-credentialed EPs using sterile technique and a SonoSite MicroMaxx US machine with a high-frequency linear array transducer. Categorical variables were evaluated using Fishers exact test, and continuous variables were analyzed using the Wilcoxon rank sum test. RESULTS Forty-two patients were enrolled, with 21 patients randomized to each group. The groups were not significantly different with respect to sex or age. The mean (±SD) LOS in the ED was significantly higher in the procedural sedation group (177.3 ± 37.9 min) than in the US-guided interscalene block group (100.3 ± 28.2 minutes; p < 0.0001). The mean (±SD) one-on-one health care provider time was 47.1 (±9.8) minutes for the sedation group and 5 (±0.7) minutes for the US-guided interscalene block group (p < 0.0001). There was no statistically significant difference between the two groups in patient satisfaction or pain experienced during the procedure. There were no significant differences between groups with respect to complications such as hypoxia or hypotension (p = 0.49). CONCLUSIONS In this study, patients undergoing shoulder dislocation reduction using US-guided interscalene block spent less time in the ED and required less one-on-one health care provider time compared to those receiving procedural sedation. There was no difference in pain level or satisfaction when compared to procedural sedation patients.

AIUM practice guideline for the performance of the focused assessment with sonography for trauma (FAST) examination.

The American Institute of Ultrasound in Medicine (AIUM) is a multidisciplinary association dedicated to advancing the safe and effective use of ultrasound in medicine through professional and public education, research, development of guidelines, and accreditation. To promote this mission, the AIUM is pleased to publish, in conjunction with the American College of Emergency Physicians (ACEP), this AIUM Practice Guideline for the Performance of the Focused Assessment With Sonography for Trauma (FAST) Examination. We are indebted to the many volunteers who contributed their time, knowledge, and energy to bringing this document to completion. The AIUM represents the entire range of clinical and basic science interests in medical diagnostic ultrasound, and with hundreds of volunteers, the AIUM has promoted the safe and effective use of ultrasound in clinical medicine for more than 50 years. This document and others like it will continue to advance this mission. Practice guidelines of the AIUM are intended to provide the medical ultra-sound community with guidelines for the performance and recording of high-quality ultrasound examinations. The guidelines reflect what the AIUM considers the minimum criteria for a complete examination in each area but are not intended to establish a legal standard of care. AIUM-accredited practices are expected to generally follow the guidelines with the recognition that deviations from the guidelines will be needed in some cases depending on patient needs and available equipment. Practices are encouraged to go beyond the guidelines to provide additional service and information as needed by their referring physicians and patients.

Change in Differential Diagnosis and Patient Management With the Use of Portable Ultrasound in a Remote Setting

Abstract Objective.—Physicians practicing in remote areas are typically limited in their choice of diagnostic tools. The goal of this study was to determine whether the use of a portable ultrasound (US) device on selected patients in a remote setting would alter physician diagnosis and management. Methods.—This was a prospective observational study of the affects of US on physician decision making deep in the Amazon jungle. A battery-operated Sonosite 180 Plus with 2 interchangeable transducers (4–7-MHz broadband intercavitary transducer and 2–5-MHz broadband abdominal transducer) was used. The patient population consisted of local tribal people. Two of the physicians on the team performed all US examinations. Team physicians requesting US examinations filled out a survey before and after the US examination. Before the US, the referring physician filled out a survey describing the patients initial complaint, pertinent past medical history and physical findings, and an initial (pre-US) differential diagnosis and planned treatment with expected disposition. After the results of the US were reviewed with the referring physicians, the doctors were asked to fill out the remainder of the survey, allowing comparison of pre- and post-US differential diagnosis, treatment plan, and disposition. Results.—A total of 25 US studies were performed during this study (1 trauma US scan, 6 hepatobiliary studies, 5 transabdominal pelvic scans, 7 transvaginal pelvic studies, 3 renal studies, and 3 abdominal aortic scans). The monitor on the US unit experienced a rare failure shortly after being used at 17,000 ft and then 10 times at sea level, and no further US scans could be performed. US scan results dramatically altered the disposition of 7 patients, including 4 patients who avoided a potentially dangerous 2-day evacuation to more definitive medical care. Three patients were found to need rapid referral to the nearest clinic for surgical evaluation. Conclusions.—When used in a remote location, portable US provides a significant benefit that can dramatically alter disposition and treatment.