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Should a Hand-carried Ultrasound Machine Become Standard Equipment for Every Internist?

2008; Elsevier BV; Volume: 122; Issue: 1 Linguagem: Inglês

10.1016/j.amjmed.2008.05.013

1555-7162

Joseph S. Alpert, Jeanette Mladenovic, David B. Hellmann,

Radiology practices and education

It has been many decades since any new piece of equipment found its way into the internist's black bag. The stethoscope, neurologic hammer, otoscope, and ophthalmoscope have been there for approximately 200 years. Recently, however, there has been a flurry of investigative work involving a new diagnostic tool with considerable potential for everyday use in internal medical practice: the portable ultrasound machine. It is an unfortunate fact that the traditional internal medicine physical examination often overlooks or erroneously interprets findings, resulting in missed or incorrect diagnoses.1Vukanovic-Criley J. Criley S. Warde C.M. et al.Competency in cardiac examination skills in medical students, trainees, physicians, and faculty.Arch Intern Med. 2006; 166: 610-616Crossref PubMed Scopus (192) Google Scholar, 2Fitzgerald F.T. Physical diagnosis versus modern technology A review.West J Med. 1990; 152: 377-382PubMed Google Scholar Noninvasive diagnostic techniques, such as ultrasound imaging, have greatly enhanced the ability of the physicians to detect occult or unapparent pathologic conditions. Recent technical advances have miniaturized ultrasound imaging equipment to the point where it can be comfortably carried and used by an internist making daily hospital rounds or working in the office. The use of such hand-held ultrasound devices has been demonstrated to increase significantly a physician's ability to detect a variety of disease states compared with physical examination alone.3Kimura B. Fowler S. Nguyen D. et al.Detection of early carotid arterial atherosclerosis by briefly trained physicians using a hand-held ultrasound device.Am J Cardiol. 2003; 92: 239-240Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar, 4Kimura B. Shaw D. Agan D. et al.Value of a cardiovascular limited ultrasound examination using a hand-carried ultrasound device on clinical management in an outpatient clinic.Am J Cardiol. 2007; 100: 321-325Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar, 5Kobal S. Trento I. Baharami S. et al.Comparison of effectiveness of hand-carried ultrasound to bedside cardiovascular physical examination.Am J Cardiol. 2005; 96: 1002-1006Abstract Full Text Full Text PDF PubMed Scopus (258) Google Scholar The cost for hand-carried ultrasound (HCU) devices has declined sharply over recent years, and the use of these systems has become increasingly more common. A full-sized office and hospital ultrasound machine, such as those used by internists and radiologists in hospitals, is approximately $250,000. The miniaturized, portable ultrasound devices range in price from $9000 to 40,000. As their use becomes more common, it is likely that prices will decline even further. What are the various areas of internal medicine in which the daily use of an HCU device might be valuable? Several organ systems have been extensively investigated with respect to the diagnostic value of HCU devices.6Kobal S. Atar S. Siegel R. Hand-carried ultrasound improves the bedside cardiovascular examination.Chest. 2004; 126: 693-701Crossref PubMed Scopus (71) Google Scholar, 7Piccoli M. Trambaiolo P. Salustri A. et al.Bedside diagnosis and follow-up of patients with pleural effusion by a hand-carried ultrasound device early after cardiac surgery.Chest. 2005; 128: 3413-3420Crossref PubMed Scopus (23) Google Scholar, 8Abboud P.C. Kendall J. Ultrasound guidance for vascular access.Emerg Med Clin N Am. 2004; 22: 749-773Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar, 9Brennan J.M. Ronan A. Goonewardena S. et al.Hand-carried ultrasound measurement of the inferior vena cava for assessment of intravascular volume status in the outpatient hemodialysis clinic.Clin J Am Soc Nephrol. 2006; 1: 749-753Crossref PubMed Scopus (125) Google Scholar, 10Galasko G. Lahiri R. Senior R. Portable echocardiography: an innovative tool for community based heart failure screening programmes.Circulation. 2001; 104: 334-335Google Scholar, 11Brennan J.M. Ronan A. Goonewardena S. et al.A comparison by medicine residents of physical examination versus hand-carried ultrasound for estimation of right atrial pressure.Am J Cardiol. 2007; 99: 1614-1616Abstract Full Text Full Text PDF PubMed Scopus (116) Google Scholar, 12Fedson S. Neithardt G. Thomas P. et al.Unsuspected clinically important findings detected with a small portable ultrasound device in patients admitted to a general medicine service.J Am Soc Echocardigr. 2003; 16: 901-905Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar These include musculoskeletal, cardiac, vascular, endocrine, renal, gastrointestinal, pulmonary, and cutaneous systems. For example, central venous intravascular cannulation is made considerably easier and safer when performed under ultrasound guidance. The same is true for thoracentesis, paracentesis, and pericardiocentesis. Aspiration from and administration of steroids into joint spaces also are made easier and more accurate when ultrasound needle guidance is used. Early carotid artery atherosclerosis can be detected accurately, leading to initiation of appropriate medical and lifestyle therapy. Thyroid nodules can be identified and often characterized with safe and accurate biopsy guided by ultrasound. Vascular volume status can be assessed. Finally, understanding the cause of unexplained dyspnea is assisted with an HCU device when left ventricular dysfunction or left atrial dilatation is identified. A number of organ-specific biopsies by subspecialists also are rendered simpler and yet accurate. Table 1 lists the many indications for portable ultrasound devices involving a large number of areas relevant to internal medicine.Table 1Questions That Can Be Answered with the Use of Portable Ultrasound in the Practice of Internal MedicineCardiacWhat is the state of left ventricular function?What is the status of intravascular volume in heart failure or other volume-overloaded states?Is a pericardial effusion present?What form of valvular heart disease is producing the murmur heard on physical examination and how severe is the lesion?Is left ventricular hypertrophy and/or left atrial dilatation present?Vascular Is carotid atherosclerosis present?Is an abdominal aortic aneurysm present?MusculoskeletalIs there an effusion present in a joint?Is there evidence of joint erosion?Is there evidence of tendon or fascial injury and/or edema?DermatologyIs a subcutaneous abscess present?PulmonaryIs a pleural effusion present?NephrologyAre 1 or both kidneys shrunken or is there evidence of obstruction (dilated calyces)?What is the intravascular volume status of the patient with renal failure?GastrointestinalIs ascitic fluid present?Is the spleen or liver enlarged and is the structure normal?Does the gall bladder have stones?EndocrineIs there a nodule(s) present in the thyroid and is it cystic or solid?Assistance with procedures: accurate, safe, and efficient aspiration of fluids or administration of fluids or medicines; needle biopsyPlacement of central venous cathetersThoracentesisParacentesisEmergency pericardiocentesisJoint fluid aspiration and administration of intra-articular steroidsBiopsy of thyroid nodulesBiopsy of specific organs by subspecialists Open table in a new tab Despite the excellent images obtained and the relative ease and efficiency of training, studies so far usually have included only small numbers of patients.13Hellman D.B. Whiting-O'Keefe Q. Shapiro E.P. et al.The rate at which residents learn to use hand-held echocardiography at the bedside.Am J Med. 2005; 118: 1010-1018Abstract Full Text Full Text PDF PubMed Scopus (93) Google Scholar, 14Martin L.D. Howell E.E. Ziegelstein R.C. et al.Hospitalist performance of hand-carried ultrasound after focused training.Am J Med. 2007; 120: 1000-1004Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar Consequently, recommendations concerning the routine use of HCU devices in many areas of internal medicine have been tentative, awaiting the results of larger, more definitive studies. It is expected that larger trials to examine the utility of these devices will be forthcoming in the near future. Nevertheless, a number of doctors and group practices have already purchased HCU devices, resulting in routine daily use in many health care settings. It has been estimated that as many as one third of US rheumatologists are already using these machines in their daily practice to assess joint effusions and erosions, fascitis, and tendon injuries (C. O. Bingham III, personal communication). Subspecialty procedures, such as central venous cannulation and aspiration of fluid from the chest and abdomen, are now routinely guided by ultrasound, as are many biopsy procedures performed on internal organs. Because these HCU devices are available, reasonable in cost, and highly accurate when used properly, how quickly, accurately, and easily can the average internal medicine trainee or physician learn to use these instruments? A number of studies have addressed this question. The simple answer is: Most medical students, trainees, and experienced clinicians can acquire, relatively rapidly, the limited skills required to use the HCU device to perform narrowly defined tasks, such as measuring left atrial size (C. O. Bingham III, MD, personal communication, 2008; R. Hoppmann, MD, personal communication, 2008).13Hellman D.B. Whiting-O'Keefe Q. Shapiro E.P. et al.The rate at which residents learn to use hand-held echocardiography at the bedside.Am J Med. 2005; 118: 1010-1018Abstract Full Text Full Text PDF PubMed Scopus (93) Google Scholar, 14Martin L.D. Howell E.E. Ziegelstein R.C. et al.Hospitalist performance of hand-carried ultrasound after focused training.Am J Med. 2007; 120: 1000-1004Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar Learning how to acquire the image is more difficult than learning how to interpret it.14Martin L.D. Howell E.E. Ziegelstein R.C. et al.Hospitalist performance of hand-carried ultrasound after focused training.Am J Med. 2007; 120: 1000-1004Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar The levels of training needed to ensure accurate use of the HCU device by nonspecialists in many areas of internal medicine have not yet been defined.14Martin L.D. Howell E.E. Ziegelstein R.C. et al.Hospitalist performance of hand-carried ultrasound after focused training.Am J Med. 2007; 120: 1000-1004Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar However, the potential value of using HCU devices to improve medical education and patient care has prompted some US medical schools to begin integrating training in the uses and indications of ultrasound into their undergraduate and postgraduate medical curricula. It is anticipated that many more schools soon will follow this pattern (R. Hoppmann, MD, personal communication, 2008). HCU devices are rapidly becoming part of the daily practice of internal medicine in the United States and throughout the world. These devices are reasonable in cost, highly efficient, and require minimal training for a physician to obtain accurate and clinically important information at the bedside or in the ambulatory setting. These devices have already increased the safety of many procedures, such as central line placement and aspiration of fluid from various internal cavities. As in any field with rapid growth, standards for performance and outcomes, cost analyses, and quality issues must be carefully studied, and the results of such studies must be disseminated throughout the health care community. The utility of HCU devices in internal medicine is undergoing active study, and those interested in this field are anxiously awaiting the setting of standards and further studies that could well lead to widespread use in hospitals, clinics, and medical offices throughout the United States.