Introduction of the Blood Pressure Cuff into U.S. Medical Practice: Technology and Skilled Practice

The blood pressure cuff has become one of the most basic and commonly used tools in medicine. The early history of this fundamental technology raises interesting questions about how new medical tools find wide acceptance in practice. In 1901, Harvey Cushing introduced a version of the modern blood pressure cuff to U.S. physicians [1]. Initially, many U.S. proponents of the new cuff encountered concern and reluctance among their colleagues. The cuff did win a secure place in practice, but only after its method of operation had been substantially changed. My review of the medical literature, systematic study of patient records from Massachusetts General Hospital, and consideration of events in Boston during this period suggest that physicians faced several important choices associated with the acceptance of the cuff into practice. What makes a new medical technology attractive to practicing physicians? Support for the clinical utility and scientific validity of blood pressure measurement appeared early and aided the acceptance of the blood pressure cuff [2, 3]. The cuff made its way into early 20th-century medicine along with other exciting new technologies, such as x-ray radiography, diagnostic serologic testing, and hemacytometers, that offered clinicians exact, objective data on disease [4-6]. The attractions of these new tools, however, were balanced by the challenges of integrating them into practice. The blood pressure cuff generated specific concerns about its introduction into regular use. Physicians questioned how the cuff would be used, who would use it, and what skills would be required or implied in its use. The blood pressure cuff won wide acceptance when it was operated in a manner that both preserved the physician's exclusive control over the tool and maintained a high level of skill for individual medical practice. By 1910, U.S. physicians had at their disposal several competing methods for assessing the force of a patient's blood flow [7, 8]. The blood pressure cuff was originally promoted as a simple tool to measure systolic blood pressure by the obliteration of the radial pulse [1]. By 1910, the modern method of auscultation with the stethoscope was a second way to measure both systolic and diastolic pressures, a way that required more skill [9]. Both of these techniques entered use alongside the already well-established method of palpating the force of blood flow in the radial artery [10]. Physicians chose among these methods in a way that expressed specific interests in the nature of their clinical practices. Harvey Cushing in Baltimore In 1901, while traveling in Europe, U.S. surgeon Harvey Cushing saw a new blood pressure instrument in clinical use at the Ospedale de S. Matteo in Pavia, Italy [1]. The instrument, a version of the modern blood pressure cuff, had been devised by Italian physician Scipione Riva-Rocci a few years earlier [11]. Cushing, stimulated perhaps by his own recent study of cerebral perfusion pressures, solicited a gift of one of the Riva-Rocci cuffs and brought it back with him to Baltimore, where he began to encourage its use among the house officers at Johns Hopkins Hospital [12]. Although other tools existed for estimating the force of blood flow, this new blood pressure cuff attracted the attention of early supporters, such as Theodore Janeway in New York City and George Crile in Cleveland [2, 3]. Cushing himself became an energetic proponent of the cuff. After 2 years' experience on the wards of the hospital, he and two of his surgical house officers, Henry Wireman Cook and John Briggs, set out to promote wider clinical use of the cuff. All three physicians recognized substantial barriers to their efforts. The introduction of the new cuff challenged the already well-established practice of pulse palpation. Physicians throughout the 19th century had taught that careful palpation of the radial pulse revealed valuable information about the force of blood flow. A standard U.S. medical text on physical examination published in the late 19th century advised the physician to palpate the patient's radial pulse for the fullness of the vessel the tension of the artery the size of the [pulse] wave the force of the wave [and] the duration of the wave [13]. The new blood pressure cuff offered a way to replace this expert, subjective assessment of the pulse with a simple number: systolic blood pressure. Briggs and Cook showed some wariness about potential conflict with this established practice in their early efforts to promote the new blood pressure cuff. In 1903, they published two papers about blood pressure measurement, each tailored to a different audience. In Maryland Medical Journal, which had a readership of practicing, community-based physicians, Cook and Briggs deferred to the accepted value of expert pulse palpation [14]. They praised that delicacy of pulse palpation which only years of experience can develop and acknowledged that the masterhand of the trained clinician derives information from the pulse that is beyond the reach of the tyro, and can never be obtained mechanically (that is, by the blood pressure cuff) [14]. They presented their new tool to this particular audience as only a modest accessory to existing clinical practices. However, in a publication for a different audience, Briggs and Cook presented a different estimate of the relative values of pulse palpation and blood pressure measurement [15]. In their second report, in Johns Hopkins Hospital Reports, Briggs and Cook addressed a readership that was more familiar with the new physiology laboratories of the time and was perhaps more open to innovation in practice. In this report, Briggs and Cook were openly critical of pulse palpation, arguing that the physician's finger on the radial pulse was the most deceptively and grossly inaccurate of all sphygmomanometers [15]. Briggs and Cook argued candidly that the new blood pressure cuff should replace an outdated reliance on complex, qualitative judgments about the pulse. Harvey Cushing in Boston Harvey Cushing took a more straightforward approach to promoting the new blood pressure cuff. In 1903, he traveled to Boston to speak at Harvard Medical School about the use of the new cuff. He opened his talk in Boston with a passing reference to pulse palpation, asserting his wish not to disparage the value of an educated touch [on the pulse] [1]. The crux of Cushing's talk, however, was his favorable comparison between the new cuff and other, familiar tools for objective medical measurement. Nurses, Cushing pointed out, already regularly used the pocket watch and the thermometer to measure pulse rate and body temperature. The cuff could be used to provide similarly standardized, quantitative data. Measuring systolic blood pressure with Riva-Rocci's new cuff required little additional skill beyond the abilities to feel the radial pulse and to read a number on a pressure gauge at the point at which the pulse was obliterated. The new blood pressure cuff, Cushing asserted, filled the need for an instrument which like the watch and the thermometer enable[d] the nurse or orderly to accumulate data, the interpretation of which remains for the visiting physician [1]. Cushing's characterization of the new blood pressure cuff was potentially reassuring. He presented the use of the cuff as distinct from expert pulse palpation and perhaps more appropriate for nonphysicians. This characterization, however, led to other concerns. Could a novel medical device be introduced into regular medical practice as a tool of nonphysicians? How would the nurse's measurement of pulse obliteration pressure with the cuff reflect on the physician's practice of assessing the tension, size, force, and duration of the pulse? The group that heard Cushing's talk in Boston immediately took up the challenge presented by the new blood pressure cuff. A group of surgeons at Harvard Medical School organized a clinical trial, distributing cuffs to three affiliated hospitals-Massachusetts General Hospital, Children's Hospital, and Boston City Hospital [16]. Physicians at the three hospitals were instructed to put the cuff into regular clinical use and to report back to a committee about the value of measuring systolic blood pressure. The group also acted on Cushing's suggestion that the cuff was appropriate for use by different medical personnel. Dr. Fred Murphy at Massachusetts General Hospital had nurses take measurements with the new cuff [17]. When the committee brought together the three reports, the verdict went against the new cuff. The investigators found that the blood pressure cuff did what it was supposed to do. It supplied a ready measurement of the pressure required to obliterate the radial pulse. In most cases, however, they found that the new data on systolic blood pressure could at best only confirm other information already available through the established practices of pulse palpation and physical examination. In other cases, the new cuff actually provided conflicting information. One physician cited an instance in which an obvious change in the quality of the pulse as assessed by palpation required rapid medical intervention, whereas the blood pressure cuff failed to register any change in the systolic pressure [18]. Such a difference was resolved in favor of the established practice of pulse palpation. The investigators at Massachusetts General Hospital did find some patients with brain injury in whom the new cuff was helpful. They noted that in some such cases, the pulse rate decreased and the circulatory force of the blood flow increased [17]. The new blood pressure cuff was helpful in documenting this unusual combination of changes, a phenomenon already noted by Cushing and later identified with his name. The Boston committee acknowledged Cushing's expert interest in brain surgery, but they showed little enthusiasm for a tool that challenged their reliance on pulse palpation. Th