Speed of Sound: Critical Care Ultrasonography at the Forefront

Leon Chen, MS, RN, AGACNP-BC, CCRN, CPEN

Critical Care NP – Memorial Sloan Kettering Cancer Center

“It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is most adaptable to change.”

-Attributed to Charles Darwin (Probably falsely)

                Ultrasound machines outside the realm of radiology started in the 1980s with trauma services. Trauma surgeons took advantage of the expediency ultrasound provided in diagnosing free fluid inside the body. Emergency medicine also embraced this technology for similar reasons. When a crashing patient arrive at the Emergency Department, often we don’t have time to wait the super STAT diagnostic test to not come in time. Bedside ultrasound allows the clinician to answer clinical questions in real time and make life and death decisions. After much posturing and political fighting, American College of Echocardiography and American College of Emergency Physicians reached consensus that Emergency Physicians have the training to utilize bedside ultrasound to make clinical decisions (1). Critical care medicine has the same need for speedy tests and thus the American College of Chest Physicians (ACCP) also put out a consensus statement establishing the standard of training for critical care ultrasound (2). As a Critical Care Medicine NP with Emergency Nursing background, having the opportunity to learn and utilize this technology is extraordinarily exciting.

                To learn ultrasound, one would need a good teacher. Dr. Elena Mead, my pulmonary critical care attending at Memorial Sloan Kettering Cancer Center’s ICU became my mentor in ultrasound early on. We bonded over this fascinating technology and through her help and MSKCC’s support I embarked on a journey to be one of the first NPs to be certified by American College of Chest Physicians in critical care ultrasonography. The program entails video lectures, in-person didactics and simulation, submission of a portfolio of ultrasound images to be critiqued and a final comprehensive exam at ACCP’s annual meeting. The process took about one year and I successfully passed my exam. Bedside ultrasound is now part of my repertoire of diagnostics tests but by far my favorite. I’ve spoken at various educational conferences about the advantage of bedside ultrasound in critical care and am now working with Dr. Mead to train all the NP/PAs in the ICU in this diagnostic tool. We at MSKCC also recently held our very first bedside ultrasound workshop that was open to the public. The workshop included didactics, images review and finally hands-on practice with live models.

            Late last year I treated a patient who was in respiratory distress. Her differentials included pneumonia, flash pulmonary, pulmonary embolism and pneumothorax. Her portable chest x-ray was grossly clear which ruled out several of those differentials. With a bedside echo, I was able to quickly determine that her respiratory distress is due in part to her acute right ventricular strain (Figure 1) and this pointed me to a potential pulmonary embolism. For a patient who was unstable and likely not tolerate supine positioning for CT, bedside ultrasound proved to be difference maker in rapid diagnosis and decision making.

The stethoscope was created over 200 years ago by a physician who didn’t like the standard practice of auscultation at that time (placing ear on patient’s chest). With time and advancing technology, portable ultrasound machines may be replacing stethoscopes around clinicians’ neck.

Figure 1: Apical 4 chamber view of a patient’s heart with severe right ventricular enlargement and pressure overload.

1) Douglas et al. ACCF/ASE/ACEP/AHA/ASNC/SCAI/SCCT/SCMR 2008 appropriateness criteria for stress echocardiography: a report of the American College of Cardiology Foundation Appropriateness Criteria Task Force, American Society of Echocardiography, American College of Emergency Physicians, American Heart Association, American Society of Nuclear Cardiology, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, and Society for Cardiovascular Magnetic Resonance: endorsed by the Heart Rhythm Society and the Society of Critical Care Medicine. Circulation. 2008 March 18; 117(11): 1478–1497

2) Mayo, Paul H., Yannick Beaulieu, Peter Doelken, David Feller-Kopman, Christopher Harrod, Adolfo Kaplan, John Oropello, Antoine Vieillard-Baron, Olivier Axler, Daniel Lichtenstein, Eric Maury, Michel Slama, and Philippe Vignon. "American College of Chest Physicians/La Société De Réanimation De Langue Française Statement on Competence in Critical Care Ultrasonography." Chest 135.4 (2009): 1050-060.