A case series of successful use of ultrasound in

  • No School
  • AA 1
  • 360

This preview shows page 336 - 338 out of 360 pages.

sound guidance was used. A case series of successful use of ultrasound in challenging cases has been described in the emergency medicine literature as well [ 20 ]. Ultrasound was used to demonstrate optimal positioning for lumbar puncture in pediatric [ 21 ] and adult [ 22 ] populations, though these two studies did not assess success rates or randomize patients to landmark- versus ultrasound-guided techniques. Figure 16.32 Marking interspinous space. 322 Procedural ultrasound Ultrasound for procedure guidance
Image of page 336

Subscribe to view the full document.

Pericardiocentesis Pericardiocentesis is the aspiration of fluid from the pericardial sac. Typic- ally, it is performed in a blind fashion by directing the needle from the subxiphoid region toward the left nipple until blood is aspirated. This method necessitates needle placement through the liver. Cardiac ultrasound has been shown to help guide pericardiocentesis in a subxiphoid, parasternal, or apical approach [ 23 –25]. When ultrasound is used to guide the procedure, a parasternal approach may be used, which involves a more direct anatomic approach to the heart than the subxiphoid approach. Note that some oper- ators prefer the parasternal approach for its shorter course, and others avoid this approach due to concern over the risk of coronary artery laceration. Thus, the optimal approach may depend on operator preference and patient factors. Visualization of the needle entering the pericardial space or visualization of agitated sterile saline injections in the pericardial space helps confirm correct placement of the cardiac needle. Also, the depth markers on the ultrasound display screen can aid in determining how deep the cardiac needle must be advanced to be in the pericardial space. Use of cardiac ultrasound in this manner may help prevent cardiac lacerations, pneumo- thorax, pneumopericardium, and liver laceration [ 23 –25]. Detection of pacing capture In transcutaneous and transvenous pacing, visualization of ventricular con- traction by cardiac ultrasound subsequent to the pacing spikes indicates that capture has been obtained. In addition, proper placement of transvenous pacing wires can be confirmed using bedside cardiac ultrasound. Transve- nous wires will appear bright or hyperechoic and can be seen within the right ventricle ( Figure 16.33 ). Ultrasound can ensure that the wire is against the right ventricular wall and in good position (and also that perforation and hemopericardium have not occurred!). [ 26 , 27 ]. Bladder aspiration Ultrasound can be used to ensure adequate volume exists within the bladder prior to catheterization. This has been shown to reduce the rates of “dry tap,” which can save time and reduce frustration and unneccesary discomfort. In cases where catheterization is unsuccessful, infeasible, or contraindicated and a supra- pubic aspiration is indicated, ultrasound can be used to guide needle placement.
Image of page 337
Image of page 338
  • Fall '19

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Ask Expert Tutors You can ask You can ask ( soon) You can ask (will expire )
Answers in as fast as 15 minutes