Srikar Adhikari

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.

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.

Sonography First for Subcutaneous Abscess and Cellulitis Evaluation

onography is an ideal imaging modality for evaluation of pathologic soft tissue conditions. High resolution and the ability to perform dynamic testing such as compressing structures allow for accurate differentiation between potentially confusing physical findings. Traditionally, clinicians assumed that any area of the skin that was erythematous and showed swelling potentially harbored an abscess. Incision and drainage has long been the standard of care in such cases and was often used as a diagnostic procedure. However, studies have confirmed anecdotal clinical evidence that the physical examination is often incorrect. In fact, not only was incision and drainage being performed unnecessarily, in some cases, needed procedures were missed after failure to recognize the presence of an abscess. With the recent spread of sonography into clinical practice, multiple descriptions of point-of-care sonography use in suspected soft tissue infections have been published. Some have even noted that blind incision and drainage, once thought to be harmless, could lead to serious potential complications because not all red swollen structures should be cut with a scalpel. This article reviews clinical scenarios in which point-of-care soft tissue sonography is useful in suspected skin infections and describes pathologic findings and commonly accepted scanning approaches.

Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest

BACKGROUND Point-of-care ultrasound has been suggested to improve outcomes from advanced cardiac life support (ACLS), but no large studies have explored how it should be incorporated into ACLS. Our aim was to determine whether cardiac activity on ultrasound during ACLS is associated with improved survival. METHODS We conducted a non-randomized, prospective, protocol-driven observational study at 20 hospitals across United States and Canada. Patients presenting with out-of-hospital arrest or in-ED arrest with pulseless electrical activity or asystole were included. An ultrasound was performed at the beginning and end of ACLS. The primary outcome was survival to hospital admission. Secondary outcomes included survival to hospital discharge and return of spontaneous circulation. FINDINGS 793 patients were enrolled, 208 (26.2%) survived the initial resuscitation, 114 (14.4%) survived to hospital admission, and 13 (1.6%) survived to hospital discharge. Cardiac activity on US was the variable most associated with survival at all time points. On multivariate regression modeling, cardiac activity was associated with increased survival to hospital admission (OR 3.6, 2.2-5.9) and hospital discharge (OR 5.7, 1.5-21.9). No cardiac activity on US was associated with non-survival, but 0.6% (95% CI 0.3-2.3) survived to discharge. Ultrasound identified findings that responded to non-ACLS interventions. Patients with pericardial effusion and pericardiocentesis demonstrated higher survival rates (15.4%) compared to all others (1.3%). CONCLUSION Cardiac activity on ultrasound was the variable most associated with survival following cardiac arrest. Ultrasound during cardiac arrest identifies interventions outside of the standard ACLS algorithm.

Pilot study to determine the utility of point-of-care ultrasound in the assessment of difficult laryngoscopy.

OBJECTIVES Prediction of difficult laryngoscopy in emergency care settings is challenging. The preintubation clinical screening tests may not be applied in a large number of emergency intubations due to the patients clinical condition. The objectives of this study were 1) to determine the utility of sonographic measurements of thickness of the tongue, anterior neck soft tissue at the level of the hyoid bone, and thyrohyoid membrane in distinguishing difficult and easy laryngoscopies and 2) to examine the association between sonographic measurements (thickness of tongue and anterior neck soft tissue) and difficult airway clinical screening tests (modified Mallampati score, thyromental distance, and interincisor gap). METHODS This was a prospective observational study at an academic medical center. Adult patients undergoing endotracheal intubation for an elective surgical procedure were included. The investigators involved in data collection were blinded to each others assessments. Demographic variables were collected preoperatively. The clinical screening tests to predict a difficult airway were performed. The ultrasound (US) measurements of tongue and anterior neck soft tissue were obtained. The laryngoscopic view was graded using Cormack and Lehane classification by anesthesia providers on the day of surgery. To allow for comparisons between difficult airway and easy airway groups, a two-sided Students t-test and Fishers exact test were employed as appropriate. Spearmans rank correlation coefficients were used to examine the association between screening tests and sonographic measurements. RESULTS The mean (±standard deviation [SD]) age of 51 eligible patients (32 female, 19 male) was 53.1 (±13.2) years. Six of the 51 patients (12%, 95% confidence interval [CI] = 3% to 20%) were classified as having difficult laryngoscopy by anesthesia providers. The distribution of laryngoscopy grades for all subjects was 63, 25, 4, and 8% for grades 1, 2, 3, and 4, respectively. In this study, 83% of subjects with difficult airways were males. No other significant differences were noted in the demographic variables and difficult airway clinical screening tests between the two groups. The sonographic measurements of anterior neck soft tissue were greater in the difficult laryngoscopy group compared to the easy laryngoscopy group at the level of the hyoid bone (1.69, 95% CI = 1.19 to 2.19 vs. 1.37, 95% CI = 1.27 to 1.46) and thyrohyoid membrane (3.47, 95% CI = 2.88 to 4.07 vs. 2.37, 95% CI = 2.29 to 2.44). No significant correlation was found between sonographic measurements and clinical screening tests. CONCLUSIONS This pilot study demonstrated that sonographic measurements of anterior neck soft tissue thickness at the level of hyoid bone and thyrohyoid membrane can be used to distinguish difficult and easy laryngoscopies. Clinical screening tests did not correlate with US measurements, and US was able to detect difficult laryngoscopy, indicating the limitations of the conventional screening tests for predicting difficult laryngoscopy.

Ultrasound-guided peripheral venous access: a meta-analysis and systematic review

Objectives The objective of this study was to determine through a systematic review of the literature and meta-analysis whether success rates, time to cannulation, and number of punctures required for peripheral venous access are improved with ultrasound guidance compared with traditional techniques in patients with difficult peripheral venous access. Methods We conducted a systematic search of MEDLINE, Web of Science, The Cochrane Library, ClinicalTrials.gov, Cumulative Index to Nursing, and Allied Health Literature. Studies were included if they met the following criteria: patients of any age identified as having difficult peripheral venous access; real-time ultrasound guidance was used for peripheral venous cannulation; and inclusion of at least one of these outcomes (success rates, time to successful cannulation and number of punctures required). Results Seven studies were selected for final analysis. Ultrasound guidance improved success rates when compared with traditional techniques [pooled odds ratio (OR) 3.96; 95% confidence interval (95% CI) 1.75-8.94]. No significant difference between ultrasound-guided techniques and traditional techniques was detected for time to cannulation or number of punctures required. Conclusions In patients with difficult peripheral venous access, ultrasound guidance increased success rates of peripheral venous placement when compared with traditional techniques. However, ultrasound guidance had no effect on time to successful cannulation or number of punctures required for successful cannulation.

Critical care ultrasound training: A survey of US fellowship directors

PURPOSE The purpose of this study is to describe the current state of bedside ultrasound use and training among critical care (CC) training programs in the United States. MATERIALS AND METHODS This was a cross-sectional survey of all program directors for Accreditation Council for Graduate Medical Education accredited programs during the 2012 to 2013 academic year in CC medicine, surgical CC, pulmonary and critical care, and anesthesia CC. Availability, current use, and barriers to training in CC ultrasound were assessed. RESULTS Sixty of 195 (31%; 95% confidence interval [CI], 24%-38%) program directors responded. Most of the responding programs had an ultrasound system available for use (54/60, 90%; 95% CI, 79%-96%) and identified ultrasound training as useful (59/60, 98%; 95% CI, 91%-100%) but lacked a formal curriculum (25/60, 42%; 95% CI, 29%-55%) or trained faculty (mean percentage of faculty trained in ultrasound: pulmonary and critical care, 25%; surgical CC, 33%; anesthesia CC, 20%; CC medicine, 7%), and relied on informal teaching (45/60, 77%; 95% CI, 62%-85%). Faculty with expertise (53/60, 88%; 95% CI, 77%-95%), simulation training (60/60, 100%; 95% CI, 94%-100%), establishing and meeting required number of examinations (47/60, 78%; 95% CI, 66%-88%), and regular review sessions (49/60, 82%; 95% CI, 70%-90%) were identified as necessary to improve ultrasound training. Most responding programs (32/35 91%; 95% CI, 77%-98%) without a formal curriculum plan to create one in the next 5 years. CONCLUSIONS This study identified deficiencies in current training, suggesting a need for a formal curriculum for bedside ultrasound training in CC fellowship programs.

Ultrasound competency assessment in emergency medicine residency programs.

OBJECTIVES In the Model of the Clinical Practice of Emergency Medicine (EM), bedside ultrasound (US) is listed as one of the essential procedural skills. EM milestones released by Accreditation Council for Graduate Medical Education and American Board of Emergency Medicine require residents to demonstrate competency in bedside US. The purpose of this study was to assess the current methods used by EM residency training programs to evaluate resident competency in bedside US. METHODS This was a cross-sectional survey study. A questionnaire on US education and competency assessment was electronically sent to all EM residency program directors and emergency US directors. The survey consisted of questions regarding the US rotation, structure of US curriculum, presence of US fellowship, image archiving, quality assurance methods, feedback, competency assessment tools, and frequency of assessment. The survey responses are reported as the percentages of total respondents along with 95% confidence intervals (CIs). RESULTS A total of 124 of 161 EM residency programs participated in this study, representing a 77% response rate. Twenty-six percent (95% CI = 18% to 34%) of programs assess competency only at the end of the US rotation. Eight percent (95% CI = 3% to 13%) assess competency only every 6 months, and 13% (95% CI = 7% to 19%) assess competency only annually. Eight percent (95% CI = 3% to 13%) assess competency only during the final year of training. Thirty percent (95% CI = 22% to 38%) of programs assess competency with a combination of the above intervals, and 16% (95% CI = 10% to 22%) do not assess US competency. Fourteen percent (95% CI = 8% to 20%) use objective structured clinical examinations (OSCEs), and 21% (95% CI = 14% to 28%) use standardized direct observation tools (SDOTs) to assess resident competency in US. Approximately one-third (33%, 95% CI = 24% to 41%) of standardized testing for US competency is conducted with multiple-choice questions. Thirty percent (95% CI = 21% to 38%) administer practical examinations to assess US skills. CONCLUSIONS Currently, a majority of EM residency programs assess resident competency in bedside US. However, there is significant variation in the methods of competency assessment.

Comparison of infection rates among ultrasound-guided versus traditionally placed peripheral intravenous lines

Objective. The purpose of this study was to compare infection rates of peripheral intravenous (IV) lines placed under ultrasound guidance with traditionally placed IV lines. Methods. We conducted a retrospective review of emergency department (ED) and hospital records of adult patients who had a peripheral IV line placed in the ED and were admitted to the hospital over a 1‐year period. This study took place at a level I academic urban ED with an annual census of 75,000. All admitted patients with a peripheral IV placed under ultrasound guidance in the ED were identified. Control patients had a traditional landmark approach. Emergency department nurses followed standard aseptic precautions when inserting both ultrasound‐guided as well as traditionally placed IV lines. Researchers reviewed all parts of the medical record, including ED and inpatient notes. Descriptive statistics and χ2 and Fisher exact tests were used in data evaluation. Results. A total of 402 patients who had peripheral IV lines placed under ultrasound guidance were compared with 402 matched control patients. In the ultrasound‐guided IV group, the mean time between insertion to catheter removal was 2.6 days compared with 2.4 days in the traditional group (P = .03). There were 2 documented infections in the ultrasound group and 3 in the traditional group, yielding infection rates of 5.2 per 1000 in the ultrasound‐guided IV group and 7.8 per 1000 in the traditional approach group. There was no statistically significant difference between infection rates in the two groups (P = .68). Conclusions. Both traditional and ultrasound‐guided approaches had low infection rates, suggesting that there is no increased risk of infection with ultrasound guidance for peripheral IV lines.

Point‐of‐care ultrasound education for non‐physician clinicians in a resource‐limited emergency department

To describe the outcomes and curriculum components of an educational programme to train non‐physician clinicians working in a rural, Ugandan emergency department in the use of POC ultrasound.