1 / 106

Novel Uses for ED Ultrasound

More than just another stethoscope. Novel Uses for ED Ultrasound. Mark Bromley Emergency Medicine PGY3. Intubation. Ocular. Ultrasound in the ED - Outline. Undifferentiated Hypotension - Echo LV function Volume Status JVP Procedures Guided Lumbar Puncture Abscess Drainage

rona
Download Presentation

Novel Uses for ED Ultrasound

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. More than just another stethoscope Novel Uses for ED Ultrasound Mark Bromley Emergency Medicine PGY3

  2. Intubation

  3. Ocular

  4. Ultrasound in the ED - Outline • Undifferentiated Hypotension - Echo • LV function • Volume Status • JVP • Procedures • Guided Lumbar Puncture • Abscess Drainage • Pleural effusion/Thoracentesis • Paracentesis • Suprapubic aspiration • Vascular Access • Joint taps

  5. Other Novel Uses • Galbladder • DVT • Ocular • Fracture Detection • Fracture Management • Renal • Pneumothorax • Intubation

  6. Undiferentiated Hypotension ...for the cardiologist in you

  7. Case • 67 ♂ • Hx of CAD and CHF • Unwell over last 2-3 days • HypotensiveTachycardic SOB

  8. Why US? Why us? • Urgent diagnostic evaluation • Timely • Limited diagnostic options due to the clinical condition → transportation of sick patients • Allow appropriate intervention and improve the course of disease

  9. Unexplained Hypotension • Cardiogenic shock • Hypovolemia - Distributive • Right ventricular infarct/large PE • Tamponade

  10. Unexplained Hypotension • As a clinician → trying to choose between inotropy, fluid resuscitation, or a needle • The ventricle is either moving well or not • The RV is dilated or not • There is an effusion or there is not • The IVC is full or not • The JVP is up or not

  11. LV Failure – fractional shortening Fractional shortening • Look at the black (i.e. blood) in the left ventricle • Systole: the black decreases in size • The ↓in size with systole is fractional shortening • Normal ejection fraction is ~ 60% • Mathematically → single dimension • (diameter rather than volume) • Change of diameter ≥30% → Gr 1 fxn • Change of diameter <30% → ↓LV systolic fxn

  12. LV Failure – fractional shortening

  13. LV Failure – LV dilatation LV dilatation • Mid-LV diameter ≤5.2cm at end-diastole • If diameter >5.2cm → LV dilatation

  14. Specific Diagnoses

  15. LV Failure • ↓ shortening fraction • LV Dilatation

  16. Hypovolemic or Distributive Shock • End-diastole → LV chamber unusually small • Systole → virtually all LV blood ejected • Cardiac Activity → hyperdynamic • fast heart rate • very vigorous contractions • Ejection fraction → exceeds 70% • IVC → low CVP

  17. Massive Pulmonary Embolus • RV is usually 2/3 the size of the LV • RV function is less formally quantified • (mathematically) complex shape • PE → RV diameter can exceed the LV diameter • Such a finding may guide diagnosis and management in the acutely dyspneic or hypotensive patient

  18. Bottom Line

  19. IVC – how to • Identify the IVC: • Just anterior to the spine • To the right of the aorta in > 99.9%. • Thin-walled (vs. the thicker-walled aorta) • Compressible with pressure • Size varies with respiration • Diameter ≤ 1.5cm→ possibly c/w ↓CVP • Diameter ≤ 1.0 cm definitely c/w ↓CVP • ↑inspiratory↑ in IVC (>25%) →↑ chance pt is dry

  20. IVC

  21. JVP – How Good Are We • Methods: • 84 consecutive patients referred for right-sided cardiac catheterization • RA pressure was acquired • Internal residents underwent 4h of formal US training and performed 20 supervised studies • Blinded to cath results examined the IVC <1h before catheterization • RA pressure was also estimated by JVP in 40 patients before right-sided cardiac catheterization • Results: • RA pressure was successfully estimated from US images of the IVC in 90% of patients, compared with 63% from JVP examination • The sensitivity for predicting RA pressure >10mm Hg was 82% with US and 14% from JVP inspection

  22. JVP …why should medicine residents have all the fun?

  23. JVP – image generation

  24. JVP

  25. Case

  26. Case

  27. Can we do it? How long does it take? Does it change what we do?

  28. Methods: • Prospective, observational study • 4 EP investigators with prior US experience → focused echo training • A convenience sample of 51 adult pts with hypotension • Exclusion criteria: • History of trauma • Chest compressions • EKG diagnostic of acute MI • Echocardiogram was recorded by an EP investigator - estimated EF and categorized LVF as normal, depressed, or severely depressed. • Blinded cardiologist reviewed all 51 studies for EF, categorization of function, and quality of the study • A second cardiologist reviewed 20 of the tapes to assess inter-observer variability between cardiologists

  29. Pearson’s correlation coefficient for EP and cardiologist estimation was R=0.86 • Pearson’s correlation coefficient for the two cardiologists’ estimations was R=0.84 • Agreement between EPs in the convenience subset of eight patients who underwent echo by two EPs yielded an R = 0.94

  30. Methods: • Prospective observational study of aconvenience sample of patients admitted to ICU • All patients underwent BLEEP followed by an independentformal echocardiogram by an experienced paediatric echocardiographyprovider (PEP) • EPs had 3 hours of focused cardiac US training including 5-proctored BLEEP examinations on unenrolled patients • IVC volume was assessed by measurement of themaximal diameter of the IVC • LVF was determined by calculatingshortening fraction (SF) • Estimates of SF and IVC volume obtained on the BLEEP were compared with those obtained by the PEP Results: • N=31 • Mean age=5.1 years (range: 23 days–16 years) • Agreementbetween the EP and the PEP for estimationof SF (r = 0.78) • The mean difference in the estimate of SFbetween the providers was 4.4% (95% CI: 1.6%–7.2%) • This difference in estimate of SF was not thought to be clinically significant • Agreement between the EP and the PEPfor estimation of IVC volume (r = 0.8). • The mean differencein the estimate of IVC diameter by the PEP and the EP was 0.068mm (95% CI: –0.16 to 0.025 mm). Conclusions: • PEP sonographers are capableof accurate assessment of LVF andIVC volume • BLEEP can be performed with focused training andoversight by a pediatric cardiologist

  31. Design: • Randomized, controlled trial of immediate vs. delayed ultrasound. • Urban, tertiary emergency department, census >100,000. • Non-trauma emergency department patients, aged >17 yrs, and initial emergency department vital signs consistent with shock (SBP<100 mm Hg or shock index >1.0), and agreement of two independent observers for at least one sign and symptom of inadequate tissue perfusion Interventions: • Group 1 (immediate ultrasound) received standard care plus goal-directed US at time 0 • Group 2 (delayed ultrasound) received standard care for 15 min and goal-directed US b/w 15-30 min Results: • Outcomes included the number of viable physician diagnoses at 15 mins and the rank of their likelihood of occurrence at both 15 and 30 mins. • N=184 • Group 1 (n = 88) had a smaller median number of viable diagnoses at 15 mins (median = 4) than did group 2 (n = 96, median = 9, Mann-Whitney U test, p < .0001). • Physicians indicated the correct final diagnosis as most likely among their viable diagnosis list at 15 mins • Group 1 80% (95% confidence interval, 70–87%) of group 1 subjects • Group 2 50% (95% confidence interval, 40–60%) in group 2 ...difference of 30% (95% confidence interval, 16–42%)

  32. 7 views • Each intended to answer a binary question: • Pericardial effusion • Pericardial tamponade • Left ventricular dysfunction • Right ventricular dilation • Intravascular volume depletion • Intraperitoneal fluid • Aortic aneurysm • On average, this information was obtained in < 6 min

  33. Conclusions: • Incorporation of a goal-directed ultrasound protocol in the evaluation of nontraumatic, symptomatic, undifferentiated hypotension in adult patients results in fewer viable diagnostic etiologies. • More accurate physician impression of final diagnosis.

  34. We can do easily We can do safely Procedures

  35. Guided Lumbar Puncture ...when you need the bariatric needle • Accurate identification of landmarks by palpation is impaired in obese patients • At least 65% of adults in the US are overweight or obese • Increasing the accuracy of landmark identification for LP may be useful

  36. Objective: • The objective of the study was to determine EPs’ ability to apply a standardized US technique for visualizing landmarks surrounding the dural space • Methods: • 2 EPs sought to identify relevant anatomy in emergency patients • Visualization time for 5 anatomical structures (spinous processes or laminae, ligamentumflavum, dura mater, epidural space, subarachnoid space), BMI, and perception of landmark palpation difficulty • Results: N=76 • Soft tissue and bony anatomical structures were identified in all subjects • Mean BMI was 31.4 (95% confidence interval, 29.1 - 33.6). • High-quality images were obtained in < 1 minute in 153 (87.9%) scans < 5 minutes in 174 (100%) scans • Mean acquisition time was 57.19 seconds; SD, 68.14 seconds; range, 10 to 300 seconds. • Conclusion: • In this cohort, EPs were able to rapidly obtain high-quality ultrasound images relevant to lumbar puncture

  37. Guided Lumbar Puncture

  38. Methods: • Cross-sectional study • Patients categorized by BMI • Recorded the difficulty in palpating traditional LP landmarks • Identification and measurement of the spatial relationships of the sacrum; spinous processes of L3, L4, L5; ligamentum flavum; and the spinal canal by US • Results: • Difficulty in palpating landmarks Normal BMI - 5% Overweight – 33% Obese - 68% ( P .0001) • Successful identification of pertinent structures Normal BMI – 100% Overweight – 95% Obese -- 74% ( P = .011) • In subjects with difficult-to-palpate landmarks, US identified pertinent structures in 16/21 (76%; 95%CI 53-92) • The average distance from skin to ligamentum flavum was 44 mm - normal BMI 51 mm - overweight 64 mm - obese • Conclusion: • As people get bigger they are harder to landmark • Ultrasound is helpful in this population – but not perfect

  39. Abscess Drainage ...where’s the pus

  40. Abscess Drainage • Cellulitis vs Abscess • Abscesses may not be clinically obvious • Is there an abscess? • What is the best area for I&D? • Are there structures near the abscess (i.e. vessels or nerves) risk?

  41. Methods: • Prospective observational ED study of adult patients with clinical STI without obvious abscess • The treating physician’s pretest opinions • need for drainage procedures • probability of subcutaneous fluid collection • Emergency US of the infected area • Effect on management plan was recorded Results: • Ultrasound changed the management in 71/126 (56%) of cases • Pretest Group • believed not to need drainage - US changed management in 39/82 (48%) • (33 drained and 6 more imaging or consultation) • believed drainage to be needed, US changed the management in 32/44 (73%) • (16 not drained and 16 more diagnostics) • US had a management effect in all pretest probabilities for fluid from 10% to 90%

  42. Conclusion • US changes ED management • Hopefully for the better

  43. Methods: • Prospective, convenience sample of adult patients with ?cellulitis +/- abscess • US was performed by EPs or residents who had attended a ½h training session in soft tissue US • yes/no assessment (of abscess) • I&D was the standard when performed • Resolution on 7d follow-up was the standard when I&D was not performed Results • N=107 • 64/107 patients had I&D–proven abscess • 17/107 had negative I&D • 26/107 improved with antibiotic therapy alone (clinically negative) • Clinical examination • Sensitivity of : 86% (95% [CI] = 76% to 93%) • Specificity: 70% (95% CI = 55% to 82%). • US • Sensitivity: 98% (95% CI = 93% to 100%) • Specificity was 88% (95% CI = 76% to 96%) • Of 18 cases in which US disagreed with the clinical examination, US was correct in 17 (94%) (x2=14.2, p = 0.0002)

  44. Clinical examination • Sensitivity of : 86% • Specificity: 70% • US • Sensitivity: 98% • Specificity was 88% • Of 18 cases in which US disagreed with the clinical exam, US was correct in 17 (94% of cases with disagreement, x2 = 14.2, p = 0.0002) Conclusions: • ED bedside US improves accuracy in detection of superficial abscesses

  45. Thoracentesis

  46. Thoracentesis – How to... • The probe should be perpendicular to the chest to ensure an accurate assessment of pleural fluid collection size, shape, and depth • Identify the diaphragm and liver or spleen • Slide the probe in the longitudinal plane towards the head and feet and then anterior-posterior or medial-lateral to locate the largest pocket of fluid

More Related