Nova L. Panebianco

Intensivist use of hand-carried ultrasonography to measure IVC collapsibility in estimating intravascular volume status: correlations with CVP.

BACKGROUND Volume status assessment is an important aspect of patient management in the surgical intensive care unit (SICU). Echocardiologist-performed measurement of IVC collapsibility index (IVC-CI) provides useful information about filling pressures, but is limited by its portability, cost, and availability. Intensivist-performed bedside ultrasonography (INBU) examinations have the potential to overcome these impediments. We used INBU to evaluate hemodynamic status of SICU patients, focusing on correlations between IVC-CI and CVP. STUDY DESIGN Prospective evaluation of hemodynamic status was conducted on a convenience sample of SICU patients with a brief (3 to 10 minutes) INBU examination. INBU examinations were performed by noncardiologists after 3 hours of didactics in interpreting and acquiring two-dimensional and M-mode images, and > or =25 proctored examinations. IVC-CI measurements were compared with invasive CVP values. RESULTS Of 124 enrolled patients, 101 had CVP catheters (55 men, mean age 58.3 years, 44.6% intubated). Of these, 18 patients had uninterpretable INBU examinations, leaving 83 patients with both CVP monitoring devices and INBU IVC evaluations. Patients in three IVC-CI ranges (<0.20, 0.20 to 0.60, and >0.60) demonstrated significant decrease in mean CVP as IVC-CI increased (p = 0.023). Although <5% of patients with IVC-CI <0.20 had CVP <7 mmHg, >40% of this group had a CVP >12 mmHg. Conversely, >60% of patients with IVC-CI >0.6 had CVP <7 mmHg. CONCLUSIONS Measurements of IVC-CI by INBU can provide a useful guide to noninvasive volume status assessment in SICU patients. IVC-CI appears to correlate best with CVP in the setting of low (<0.20) and high (>0.60) collapsibility ranges. Additional studies are needed to confirm and expand on findings of this study.

Diagnosing heart failure among acutely dyspneic patients with cardiac, inferior vena cava, and lung ultrasonography☆ , ☆☆ ,★

BACKGROUND Rapid diagnosis (dx) of acutely decompensated heart failure (ADHF) may be challenging in the emergency department (ED). Point-of-care ultrasonography (US) allows rapid determination of cardiac function, intravascular volume status, and presence of pulmonary edema. We test the diagnostic test characteristics of these 3 parameters in making the dx of ADHF among acutely dyspneic patients in the ED. METHODS This was a prospective observational cohort study at an urban academic ED. Inclusion criteria were as follows: dyspneic patients, at least 18 years old and able to consent, whose differential dx included ADHF. Ultrasonography performed by emergency sonologists evaluated the heart for left ventricular ejection fraction (LVEF), the inferior vena cava for collapsibility index (IVC-CI), and the pleura sampled in each of 8 thoracic regions for presence of B-lines. Cutoff values for ADHF were LVEF less than 45%, IVC-CI less than 20%, and at least 10 B-lines. The US findings were compared with the final dx determined by 2 emergency physicians blinded to the US results. RESULTS One hundred one participants were enrolled: 52% male, median age 62 (25%-75% interquartile, 53-91). Forty-four (44%) had a final dx of ADHF. Sensitivity and specificity (including 95% confidence interval) for the presence of ADHF were as follows: 74 (65-90) and 74 (62-85) using LVEF less than 45%, 52 (38-67) and 86 (77-95) using IVC-CI less than 20%, and 70 (52-80) and 75 (64-87) using B-lines at least 10. Using all 3 modalities together, the sensitivity and specificity were 36 (22-51) and 100 (95-100). As a comparison, the sensitivity and specificity of brain natriuretic peptide greater than 500 were 75 (55-89) and 83 (67-92). CONCLUSION In this study, US was 100% specific for the dx of ADHF.

What You See (Sonographically) Is What You Get: Vein and Patient Characteristics Associated With Successful Ultrasound-guided Peripheral Intravenous Placement in Patients With Difficult Access

OBJECTIVES Ultrasound (US) has been shown to facilitate peripheral intravenous (IV) placement in emergency department (ED) patients with difficult IV access (DIVA). This study sought to define patient and vein characteristics that affect successful US-guided peripheral IV placement. METHODS This was a prospective observational study of US-guided IV placement in a convenience sample of DIVA patients in an urban, tertiary care ED. DIVA patients were defined as having any of the following: at least two failed IV attempts or a history of difficult access plus the inability to visualize or palpate any veins on physical exam. Patient characteristics (demographic information, vital signs, and medical history) were collected on enrolled patients. The relationships between patient characteristics, vein depth and diameter, US probe orientation, and successful IV placement were analyzed. RESULTS A total of 169 patients were enrolled, with 236 attempts at access. Increasing vessel diameter was associated with a higher likelihood of success (odds ratio [OR] = 1.79 per 0.1-cm increase in vessel diameter, 95% confidence interval [CI] = 1.37 to 2.34). Increasing vessel depth did not affect success rates (OR = 0.96 per 0.1-cm increase of depth, 95% CI = 0.89 to 1.04) until a threshold depth of 1.6 cm, beyond which no vessels were successfully cannulated. Probe orientation and patient characteristics were unrelated to success. CONCLUSIONS Success was solely related to vessel characteristics detected with US and not influenced by patient characteristics or probe orientation. Successful DIVA was primarily associated with larger vessel, while vessel depth up to >1.6 cm and patient characteristics were unrelated to success. Clinically, if two vessels are identified at a depth of <1.6 cm, the larger diameter vessel, even if comparatively deeper, should yield the greatest likelihood of success.

Emergency ultrasound-assisted examination of skin and soft tissue infections in the pediatric emergency department.

OBJECTIVES The objective was to evaluate the test characteristics of clinical examination (CE) with the addition of bedside emergency ultrasound (CE+EUS) compared to CE alone in determining skin and soft tissue infections (SSTIs) that require drainage in pediatric patients. METHODS This was a prospective study of CE+EUS as a diagnostic test for the evaluation of patients 2 months to 19 years of age evaluated for SSTIs in a pediatric emergency department (ED). Two physicians clinically and independently evaluated each lesion, and the reliability of the CE for diagnosing lesions requiring drainage was calculated. Trained pediatric emergency physicians performed US following their CEs. The authors determined and compared the test characteristics for evaluating a SSTI requiring drainage for CE alone and for CE+EUS for those lesions in which the two physicians agreed and were certain regarding their CE diagnosis (clinically evident). The performance of CE+EUS was evaluated in those lesions in which the two physicians either disagreed or were uncertain of their diagnosis (not clinically evident). The reference standard for determining if a lesion required drainage was defined as pus expressed at the time of the ED visit or within 2 days by follow-up assessment. RESULTS A total of 387 lesions underwent CE+EUS and were analyzed. CE agreement between physicians was fair (κ = 0.38). For the 228 lesions for which physicians agreed and were certain of their diagnoses, sensitivity was 94.7% for CE and 93.1% for CE+EUS (difference = -1.7%; 95% confidence interval [CI] = -3.4% to 0%). The specificity of CE was 84.2% compared to 81.4% for CE+EUS (difference = -2.8%; 95% CI = -9.7% to 4.1%). For lesions not clinically evident based on CE, the sensitivity of CE was 43.7%, compared with 77.6% for CE+EUS (difference = 33.9%; 95% CI = 1.2% to 66.6%). The specificity of CE for this group was 42.0%, compared with 61.3% for CE+EUS (difference = 19.3%; 95% CI = -13.8% to 52.4%). CONCLUSIONS For clinically evident lesions, the addition of ultrasound (US) did not significantly improve the already highly accurate CE for diagnosing lesions requiring drainage in this study population. However, there were many lesions that were not clinically evident, and in these cases, US may improve the accuracy of the CE.

Simple, almost anywhere, with almost anyone: remote low-cost telementored resuscitative lung ultrasound.

BACKGROUND Apnea (APN) and pneumothorax (PTX) are common immediately life-threatening conditions. Ultrasound is a portable tool that captures anatomy and physiology as digital information allowing it to be readily transferred by electronic means. Both APN and PTX are simply ruled out by visualizing respiratory motion at the visceral-parietal pleural interface known as lung sliding (LS), corroborated by either the M-mode or color-power Doppler depiction of LS. We thus assessed how economically and practically this information could be obtained remotely over a cellular network. METHODS Ultrasound images were obtained on handheld ultrasound machines streamed to a standard free internet service (Skype) using an iPhone. Remote expert sonographers directed remote providers (with variable to no ultrasound experience) to obtain images by viewing the transmitted ultrasound signal and by viewing the remote examiner over a head-mounted webcam. Examinations were conducted between a series of remote sites and a base station. Remote sites included two remote on-mountain sites, a small airplane in flight, and a Calgary household, with base sites located in Pisa, Rome, Philadelphia, and Calgary. RESULTS In all lung fields (20/20) on all occasions, LS could easily and quickly be seen. LS was easily corroborated and documented through capture of color-power Doppler and M-mode images. Other ultrasound applications such as the Focused Assessment with Sonography for Trauma examination, vascular anatomy, and a fetal wellness assessment were also demonstrated. CONCLUSION The emergent exclusion of APN-PTX can be immediately accomplished by a remote expert economically linked to almost any responder over cellular networks. Further work should explore the range of other physiologic functions and anatomy that could be so remotely assessed.

The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity

INTRODUCTION Ultrasound-guided peripheral intravenous catheters (USGPIVs) have been observed to have poor durability. The current study sets out to determine whether vessel characteristics (depth, diameter, and location) predict USGPIV longevity. METHODS A secondary analysis was performed on a prospectively gathered database of patients who underwent USGPIV placement in an urban, tertiary care emergency department. All patients in the database had a 20-gauge, 48-mm-long catheter placed under ultrasound guidance. The time and reason for USGPIV removal were extracted by retrospective chart review. A Kaplan-Meier survival analysis was performed. RESULTS After 48 hours from USGPIV placement, 32% (48/151) had failed prematurely, 24% (36/151) had been removed for routine reasons, and 44% (67/151) remained in working condition yielding a survival probability of 0.63 (95% confidence interval [CI], 0.53-0.70). Survival probability was perfect (1.00) when placed in shallow vessels (<0.4 cm), moderate (0.62; 95% CI, 0.51-0.71) for intermediate vessels (0.40-1.19 cm), and poor (0.29; 95% CI, 0.11-0.51) for deep vessels (≥1.2 cm); P < .0001. Intravenous survival probability was higher when placed in the antecubital fossa or forearm locations (0.83; 95% CI, 0.69-0.91) and lower in the brachial region (0.50; 95% CI, 0.38-0.61); P = .0002. The impact of vessel depth and location was significant after 3 hours and 18 hours, respectively. Vessel diameter did not affect USGPIV longevity. CONCLUSION Cannulation of deep and proximal vessels is associated with poor USGPIV survival. Careful selection of target vessels may help improve success of USGPIV placement and durability.

Inter-Rater Reliability of Quantifying Pleural B-Lines Using Multiple Counting Methods

Sonographic B‐lines are a sign of increased extravascular lung water. Several techniques for quantifying B‐lines within individual rib spaces have been described, as well as different methods for “scoring” the cumulative B‐line counts over the entire thorax. The interobserver reliability of these methods is unknown. This study examined 3 methods of quantifying B‐lines for inter‐rater reliability.

Assessment of a Training Curriculum for Emergency Ultrasound for Pediatric Soft Tissue Infections

OBJECTIVES The objective was to evaluate a training protocol for pediatric emergency physicians (EPs) learning emergency ultrasound (EUS) for the evaluation of skin and soft tissue infections (SSTIs) by assessing technical ability and interrater reliability. METHODS Pediatric emergency medicine (EM) fellows and attending physicians completed a 1-day training course taught by an expert emergency sonologist. After the course, EPs performed proctored examinations on patients with SSTIs until they reached predefined performance criteria, after which they performed independent EUS examinations. All EUS examinations were recorded using still images and video clips that were reviewed and rated by the expert sonologist on four technical measures and combined into a composite score. The experts opinion regarding the presence or absence of an abscess was also compared to the study sonologists opinion and analyzed for interrater reliability. RESULTS Seven EPs performed 107 EUS examinations. The mean (±SD) composite score for the evaluation of technical ability for the first EUS was 3.3 ± 0.14 (on a 4-point scale), indicating a high level of quality following the training course. There was a small amount of improvement in the quality score (0.015, 95% confidence interval [CI] = 0.0003 to 0.03) with each consecutive EUS examination. The interrater reliability between the sonologist and the expert for the presence of an abscess as measured by the kappa statistic was 0.80 (95% CI = 0.63 to 0.97), indicating substantial agreement. CONCLUSIONS After a brief training program, pediatric EPs can perform technically successful emergency EUS examination of SSTIs, with excellent agreement with an expert sonologist.

Point-of-Care Ultrasonography by Pediatric Emergency Physicians

Point-of-care ultrasonography is increasingly being used to facilitate accurate and timely diagnoses and to guide procedures. It is important for pediatric emergency physicians caring for patients in the emergency department to receive adequate and continued point-of-care ultrasonography training for those indications used in their practice setting. Emergency departments should have credentialing and quality assurance programs. Pediatric emergency medicine fellowships should provide appropriate training to physician trainees. Hospitals should provide privileges to physicians who demonstrate competency in point-of-care ultrasonography. Ongoing research will provide the necessary measures to define the optimal training and competency assessment standards. Requirements for credentialing and hospital privileges will vary and will be specific to individual departments and hospitals. As more physicians are trained and more research is completed, there should be one national standard for credentialing and privileging in point-of-care ultrasonography for pediatric emergency physicians.

Imaging and Laboratory Testing in Acute Abdominal Pain

When discussing which laboratory tests or imaging to order in the setting of acute abdominal pain, it is practical to organize information by disease process (eg, acute appendicitis, cholecystitis). Because studies on the accuracy of diagnostic tests are of necessity related to the presence or absence of specific diagnoses, and because clinicians frequently look to tests to help them rule in or rule out specific conditions, this article is organized by region of pain and common abdominal diagnoses. It focuses on the contributions that laboratory testing and imaging make in the emergency management of abdominal complaints.