Examination Techniques and Equipment

Jane W. Brawl DrPH, RN, CPNP , in Seidel'south Guide to Physical Examination , 2019

Stethoscope

Auscultation of nigh sounds requires a stethoscope. Three basic types are available: acoustic, magnetic, and electronic (also called digital).

The acoustic stethoscope is a closed cylinder that transmits sound waves from their source and along its column to the ear (Fig. 3.vii). Its rigid diaphragm has a natural frequency of effectually 300 Hz. Information technology screens out depression-pitched sounds and best transmits high-pitched sounds such as the second heart audio. The bell end piece has a natural frequency that varies with the corporeality of pressure exerted. It transmits low-pitched sounds when very light pressure level is used. With firm pressure level, the skin converts it to a diaphragm terminate piece. The breast piece contains a closure valve then that just one end piece, either the diaphragm or bong, is operational at whatever i fourth dimension (thus preventing inadvertent dissipation of sound waves).

The stereophonic stethoscope, a blazon of acoustic stethoscope, is used to differentiate between the right and left auscultatory sounds using a ii-channel design (Fig. 3.8). With a single tube, diaphragm, and bell, it looks and functions like an acoustic stethoscope. Notwithstanding, the correct and left ear tubes are independently continued to right and left semicircular microphones in the chest piece.

The magnetic stethoscope has a single end slice that is a diaphragm. It contains an iron deejay on the interior surface; behind this is a permanent magnet. A strong spring keeps the diaphragm bowed outward when information technology is not compressed against a trunk surface. Pinch of the diaphragm activates the air column as magnetic attraction is established between the iron deejay and the magnet. Rotation of a dial adjusts for high-, depression-, and full-frequency sounds.

The electronic stethoscope picks up vibrations transmitted to the surface of the body and converts them into electrical impulses. The impulses are amplified and transmitted to a speaker, where they are reconverted to audio. Newer versions of the electronic stethoscope can also provide additional features such every bit extended listening ranges, digital readout, audio recording and storage, playback, murmur interpretation, visual brandish, tubeless connection, and electronic device linkage.

The traditional and most commonly used is the acoustic stethoscope, which comes in several models. The power to auscultate accurately depends in role on the quality of the instrument, so it is important that the stethoscope have the following characteristics:

•

The diaphragm and bell are heavy plenty to lie firmly on the body surface.

•

The diaphragm cover is rigid.

•

The bell is large enough in diameter to span an intercostal space in an adult and deep enough so that it volition not fill with tissue.

•

The bell and diaphragm are pediatric-sized for use in children

•

A rubber or plastic band is around the bell edges to ensure secure contact with the body surface.

•

The tubing is thick, strong, and heavy; this conducts better than thin, rubberband, or very flexible tubing.

•

The length of the tubing is between thirty.5 and 40 cm (12 and 18 inches) to minimize distortion.

•

The earpieces fit snugly and comfortably. Some instruments have several sizes of earpieces and some have hard and soft earpieces. The determining factors are how they fit and feel to the examiner. The earpieces should be large plenty to occlude the auditory canal, thus blocking exterior sound. If they are too small, they volition sideslip into the ear culvert and be painful.

•

Angled binaurals point the earpieces toward the olfactory organ and then that sound is projected toward the tympanic membrane.

To stabilize the stethoscope when it is in place, hold the end slice between the fingers, pressing the diaphragm firmly against the skin (Fig. 3.ix). The diaphragm slice should never exist used without the diaphragm. Considering the bell functions by picking up vibrations, it must be positioned so that the vibrations are not dampened. Place the bell evenly and lightly on the peel, making sure there is peel contact around the entire edge. To prevent extraneous noise, do not touch the tubing with your easily or allow the tubing to rub against any surfaces.

Concrete Cess Skills

Karen J. Tietze PharmD , in Clinical Skills for Pharmacists (3rd Edition), 2012

Stethoscope

The stethoscope, an of import auscultatory tool, consists of two earpieces angled at the same angle as the ear canal, rubber tubing, and a head with either a diaphragm (plastic disc) or a bell (hollow loving cup) (Figure 4-three). The diaphragm accentuates high-frequency sounds; the bell transmits low-frequency sounds (Figure 4-4). Dual-headed stethoscopes have both a diaphragm and a bell. Some stethoscopes have only a diaphragm (no bell); some stethoscopes have a pressure-sensitive tunable head that functions every bit both a diaphragm and bell depending on the applied pressure. Stethoscopes are available in a variety of styles (Figure four-five) and price ranges, including electronically amplified stethoscopes. Although the option of style (e.g., Sprague-Rappaport type with dual tubing, Littman blazon with a single tube) depends on personal preference, quality is important. College-quality stethoscopes transmit sounds more efficiently and are more durable than cheaper models. The earpieces should fit the ear canals snugly and comfortably; the goal is for the sound to exist transmitted from the patient to the eardrum through an unbroken system. Near loftier-quality stethoscopes come with several different sizes and shapes of ear tips, which enables the user to select the best-fitting and most comfortable tips.

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History and Concrete Examination

5. Courtney Broaddus Medico , in Murray & Nadel's Textbook of Respiratory Medicine , 2022

Auscultation

A stethoscope draped around the neck has long been the badge of the medical professional, and information technology is worn with pride by physicians, nurses, and respiratory therapists, despite predictions such every bit "it, too, will someday be relegated to a museum shelf." 63 This will non happen for a long time, however, according to Spud, 64 who mounts a spirited defense of stethoscopes backed up by analyses of jiff sounds obtained by respiratory acoustic recording. The fundamentals of lung auscultation in physical examination are also covered in this review. 65

Stethoscopes are also helpful in identifying pathology when chest radiograph findings are normal, such as detecting wheezes in asthmatic patients or crackles in patients with interstitial lung disease. Moreover, patients with cardiorespiratory complaints expect their physicians to heed to their heart and lungs.

Like whatever slice of medical equipment, there are a number of available choices, and the design and care of the stethoscope may have a substantial impact on performance. Electronic models promise ambient dissonance reduction and audio amplification, features shown in randomized trials to provide statistically significant improvements in acoustics, peculiarly in noisy environments. 66 , 67 Even so, the magnitude of comeback is small-scale relative to the all-time acoustic stethoscopes, and electronic stethoscopes have not been shown to improve trainee performance. 68 Sound quality with whatever stethoscope tin can be substantially degraded by failure to maintain the integrity of the prophylactic fittings, and prolonged contact of the tubing with the peel when worn around the neck tin can lead to hardening of the tubing and decreased functioning. In any case, the stethoscope must be kept clean because it is increasingly recognized as a vector of nosocomial infection. 69 Glycerin-free isopropyl alcohol wipes are gentler on safety and preferred to chlorine bleach except whenClostridium difficile colitis is possible; soap and h2o is an alternative, provided all internal pieces are allowed to dry.

The terminology of breath sounds has been standardized and simplified to enhance understanding and advice (Table 18.3). Although standardized nomenclature has been proposed by the American Thoracic Social club 70 and the Tenth International Briefing on Lung Sounds, 71 communication at the bedside often strays from recommended terminology. Although a number of other nonstandard terms (e.g., vesicular jiff sounds, fibroid jiff sounds, rales, crepitations, sibilant and sonorous rhonchi, and loftier- and depression-pitched wheezes) may be encountered based on historical usage, on homologies with terms used in languages other than English, or on common usage, we encourage adherence to this standard classification. 72

Emergency Airway Management

Paul South. Auerbach MD, MS, FACEP, FAWM , ... Eric A. Weiss Md, FACEP , in Field Guide to Wilderness Medicine (3rd Edition), 2008

Stethoscope

A stethoscope is a useful addition to the trek first-aid kit. However, auscultating breath sounds without a stethoscope is easy:

i.

Place the ear directly to the chest.

two.

Isolate and amplify the breath sounds by listening through a hollow object such equally a modified loving cup, empty water bottle or soda tin can, or through the cardboard centre of a curlicue of toilet newspaper.

3.

The boosted merit of a real stethoscope is that it can exist disassembled to harvest compliant tubing that might be used improvisationally to substitute for nasopharyngeal airways, cricothyrotomy tubes or stents, straws for suction devices, chest tubes, restraining tethers, lymphatic constriction bands, or other medical devices.

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History and Physical Examination

J. Lucian Davis MD , John F. Murray Doc , in Murray and Nadel'due south Textbook of Respiratory Medicine (Sixth Edition), 2016

Auscultation

A stethoscope draped around the neck has long been the badge of the medical professional, and it is worn with pride past physicians, nurses, and respiratory therapists, despite predictions such as "it, too, will someday be relegated to a museum shelf." 67 This will non happen for a long time, according to Murphy, 68 who mounts a spirited defence force of stethoscopes backed up past analyses of breath sounds obtained past respiratory acoustic recording. Indeed, there is now a body of literature on figurer-assisted mapping of jiff sounds using both recording and imaging techniques which provides new insights into their origin and clinical significance. 69-71 For example, computerized multisensor jiff sound imaging has proved to exist a sensitive and specific tool for differentiating pneumonia or pleural effusion from normal lungs. 72 Similarly, point analysis of middle sounds recorded by digital electronic means has promising clinical applications and is useful for teaching cardiac auscultation. 73 The fundamentals of lung auscultation in physical test have been reviewed recently. 74

Stethoscopes are also helpful in picking upwards wheezes in asthmatics and crackles in patients with interstitial lung disease whose chest radiograph findings are normal. Moreover, patients expect their physicians to listen to their hearts and lungs if they have cardiorespiratory complaints.

Like whatsoever piece of medical equipment, there are a number of bachelor choices, and the pattern and care of the stethoscope may have a substantial impact on its operation. Electronic models hope ambient racket reduction and sound amplification, features that take been shown in randomized trials to provide statistically meaning improvements in acoustics, especially in noisy environments. 75,76 However, the magnitude of improvement is small relative to the best audio-visual stethoscopes, and electronic stethoscopes have not been shown to better trainee performance. 77 Sound quality with any stethoscope can be essentially degraded by failure to maintain the integrity of the prophylactic fittings, and prolonged contact of the tubing with the peel when worn around the cervix can lead to hardening of the tubing and decreased functioning. In any case, the stethoscope must exist kept clean considering it is increasingly recognized as a vector of nosocomial infection. 78

The terminology of breath sounds has been standardized and simplified to enhance understanding and communication (Table 16-2). Although a standardized nomenclature has been proposed by the American Thoracic Social club 79 and the Tenth International Conference on Lung Sounds, fourscore communication at the bedside often strays from recommended terminology.

The bones technique of auscultation with an ordinary stethoscope is well known to virtually physicians: the diaphragm detects college-pitched sounds, and the bell detects lower-pitched sounds, although if the bell is tightly pressed against the body, the taut underlying skin itself may serve as a "diaphragm" and meliorate perception of higher pitches. Conversely, the bong should exist applied very lightly to hear, for instance, the low-pitched rumble of mitral stenosis. Total contact with the skin is necessary for best listening, which may pose a problem in a patient whose intercostal spaces are sunken from weight loss. In addition, the skin or hairs may brush against the diaphragm and produce a sound that resembles a pleural friction rub. As with examiners' hands, a warm stethoscope head is appreciated by patients. The importance of a tranquility room and of applying the stethoscope directly to the peel rather than through habiliment has recently been reemphasized. 81 At times, specially in the intensive intendance unit, it is non always possible to sit patients up to listen carefully to their backs, which compromises the completeness of auscultation.

This chapter includes links to audio recordings, some with animations. To hear the recorded lung sounds at their intended pitch and intensity, it is recommended that readers listen through a stethoscope, with the chest piece held 4–five inches from the sound speaker.

The recommended terminology for the ordinary breathing-associated sounds heard with a stethoscope placed on the breast of a healthy person is normal lung sounds, but, every bit shown in Tabular array 16-2, many physicians prefer the older term vesicular jiff sounds (Audio 16-1

). The normally predominating inspiratory component arises from sounds generated by turbulent airflow within the lobar and segmental bronchi, whereas the weaker expiratory component arises within the larger, more fundamental airways. 79 Sounds are attenuated as they movement peripherally forth the air passages and are further damped by the large book of the lungs' air spaces. The intensity of normal breath sounds varies with the magnitude of regional ventilation and, like percussion notes, diminishes with increasing thickness of the tissue overlying the breast wall. There is considerable variation amongst persons in the quality of jiff sounds, which makes it essential to compare jiff sounds from one side with those heard over the same location on the opposite hemithorax.

The transmission of normal lung sounds to the chest wall in pathologic conditions may be either attenuated or exaggerated. When the lung parenchyma is consolidated and the airway leading to the involved region is patent, breath sounds are well transmitted to the chest wall and are termed bronchial jiff sounds (Audio 16-2

). Bronchial breath sounds are loud, high-pitched, tubular, or whistling sounds with expiration as loud every bit or louder than with inspiration. Bronchial breath sounds are similar to tracheal jiff sounds (Audio 16-3), and their presence is the classic auscultatory sign of pneumonia with consolidation. Similar sounds are heard in patients with other types of consolidation, such every bit pulmonary edema and hemorrhage. The presence of this sign assumes that the sounds originate centrally and reach the breast wall. 82

Interposition of a sound barrier betwixt the central airways where sounds originate and the chest wall where they are heard as well attenuates or interrupts transmission of normal lung sounds. Accordingly, normal breath sounds are diminished or absent over a pleural effusion, pneumothorax, and peripheral bullae, or distal to an obstructing mass lesion. Conversely, they may be increased if chest wall deformity or bronchial or tracheal derangement allows move of air to be closer than usual to the stethoscope.

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Auscultation of the Heart

Steven McGee MD , in Evidence-Based Physical Diagnosis (Fourth Edition), 2018

Two The Stethoscope

A Bell and Diaphragm

The stethoscope has ii different heads to receive sound, the bong and the diaphragm. The bong is used to detect low-frequency sounds and the diaphragm to detect high-frequency sounds.

The traditional caption that the bong selectively transmits low-frequency sounds and the diaphragm selectively filters out depression-frequency sounds is probably incorrect. Actually, the bell transmits all frequencies well, merely in some patients with loftier-frequency murmurs (e.yard., aortic regurgitation), whatever additional low-frequency sound masks the loftier-frequency sound and makes the murmur difficult to observe. three The diaphragm does not selectively filter out depression-frequency sounds just instead attenuates all frequencies equally, thus dropping the barely aural depression-frequency ones below the threshold of human hearing. 3

B Operation of Different Stethoscope Models

Many studies have examined the acoustics of stethoscopes, but the clinical relevance of this research has never been formally tested. In general, these studies bear witness that shallow bells transmit audio also as deeper bells and that double tube stethoscopes are equivalent to single tube models. 3 The optimal internal bore of a stethoscope is somewhere between i-eighth and iii-sixteenths of an inch because smaller bores diminish transmission of the higher frequency sounds. one,4,v Compared with shorter lengths of stethoscope tubing, longer tubes also impair the conduction of high-frequency sounds. 1

Nonetheless, well-nigh modern stethoscopes transmit sound as well, the differences among various models for unmarried frequencies existence very small. 3 The most of import source of poor acoustic performance is an air leak, which typically results from poorly fitting ear pieces. Even a tiny air leak with a diameter of only 0.015 inch will diminish manual of sound past every bit much equally 20 dB, ∗ especially for those sounds less than 100 Hz. 6

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Auscultation of the Heart: General Principles

In Evidence-Based Physical Diagnosis (2d Edition), 2007

II THE STETHOSCOPE

A BELL AND DIAPHRAGM

The stethoscope has two different heads to receive audio, the bong and the diaphragm. The bell is used to observe low-frequency sounds; the diaphragm, high-frequency sounds.

The traditional explanation that the bell selectively transmits low-frequency sounds and the diaphragm selectively filters out low-frequency sounds is probably incorrect. Actually, the bell transmits all frequencies well, merely in some patients with high-frequency murmurs (e.m., aortic regurgitation), whatsoever boosted low-frequency sound masks the high-frequency sound and makes the murmur difficult to detect. iii The diaphragm does not selectively filter out low-frequency sounds, but instead attenuates all frequencies equally, thus dropping the barely aural low-frequency ones below the threshold of human hearing. 3

B PERFORMANCE OF Different STETHOSCOPE MODELS

Many studies have examined the acoustics of stethoscopes, just the clinical relevance of this enquiry has never been formally tested. In general, these studies show that shallow bells transmit audio as well as deeper bells and that double tube stethoscopes are equivalent to unmarried tube models. 3 The optimal internal bore of a stethoscope is somewhere between 1/8 and 3/16 inch, because smaller bores diminish transmission of the higher frequency sounds. 1, four, 5 Compared with shorter lengths of stethoscope tubing, longer tubes also impair the conduction of high-frequency sounds. 1

Almost modern stethoscopes, however, transmit sound equally well, the differences amongst diverse models for single frequencies being very small. three The most important source of poor acoustic performance is an air leak, which typically results from poorly fitting ear pieces. Even a tiny air leak with a diameter of only 0.015 inch volition diminish manual of sound by as much as 20 dB,* particularly for those sounds less than 100 Hz. six

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Claret Pressure

Steven McGee Md , in Evidence-Based Physical Diagnosis (Third Edition), 2012

three Stethoscope Pressure Likewise House

Excessive pressure level with the stethoscope artificially lowers the diastolic reading, sometimes by x mm Hg or more, although the systolic reading is unremarkably unaffected. 39 This error occurs because the stethoscope pressure then contributes to the collapse of the underlying avenue (i.e., the full tissue force per unit area around the artery represents the sum of both cuff and stethoscope pressure level). If the clinician applies 10 mm Hg of stethoscope pressure to the arm of a patient whose intra-arterial diastolic pressure is 80 mm Hg, the diastolic reading will be lxx mm Hg (i.east., Korotkoff sounds disappear at a tissue pressure of lxxx mm Hg = 70 mm Hg cuff force per unit area—the ground for the reading—and x mm Hg of stethoscope pressure level).

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IS4Learning—A Multiplatform Simulation Technology to Teach and Evaluate Auscultation Skills

Daniel Pereira , ... Miguel Tavares Coimbra , in Health Professionals' Education in the Age of Clinical Information Systems, Mobile Computing and Social Networks, 2017

The (Near) Lost Fine art of Auscultation

The stethoscope is the oldest cardiovascular diagnostic instrument in clinical use ( Fig. 19.ane). Invented in 1816 past Laënnec, what outset was a more 'modest' manner to listen to heart sounds than direct application of the ear in a patient's chest, quickly revealed itself equally a powerful way to enhance heart sounds and it is notwithstanding considered the about cost-effective manner to perform the outset layer of screening of cardiopulmonary affliction [1]. By auscultating the heart, we accept an understanding of cardiac rate and rhythm, the audio of the closing and, sometimes, the opening of valves, and anatomical abnormalities such as congenital or caused defects. Heart sounds are caused by turbulent blood flow, while laminar period is silent. When used properly the stethoscope ofttimes enables physicians to brand a rapid and an accurate diagnosis without any additional studies. However, cardiac auscultation is in decline and the lack of ability to either hear or translate a cardiac aberration starts with medical students and continues through to physicians of unlike ages [ii]. Understanding these sounds is a difficult skill to master. Relevant pathological activity is often soft, short-lived and occurs in proximity to loud, normal activity: a typical murmur is 1000 times softer than normal center sounds and can last for equally piffling as thirty milliseconds [3].

Figure 19.1. The evolution of the stethoscope: (A) Original Laennec stethoscope (1816); (B) Cammann binaural stethoscope (1852); (C) Kerr Symballophone (1940); (D) Rappaport-Sprague stethoscope (1960); (E) Original Littmann stethoscope (1961); and (F) Littmann electronic stethoscope model 4000 (2000).

 Adapted from Medical Antiques Online [Medical Antiques Online]; used with permission.

Medical simulation is a rapidly evolving field, bridging the gap between medicine and technology, and is perceived by many as the future of medical education to forbid the continuously rising costs of training time to come doctors. Predictions consider that this medical simulation market volition reach numbers every bit high as 2.27 billion USD by 2021 [four]. Motivated past all of this, our main objective in this chapter is to present a perspective on how virtual patient technologies, namely, one called IS4Learning, can address these difficulties in the teaching of auscultation.

Is auscultation condign a lost fine art? Some believe the stethoscope has go the forgotten instrument in cardiology [5] and auscultation has lost its importance. Can we really afford to lose this technique and its respective know-how?

Many factors have conspired to limit adequate teaching and maintenance of cardiac auscultation skills. Indeed, the requirements and expectations of junior doctors, with regard to auscultation, are much lower now than in previous generations [6]. A major reason for poor auscultation skills is that teaching methods have inverse little in the last fifty years, and the number of medical students today is significantly larger. If we associate this with technological advancements such as ultrasonic imaging and Doppler techniques, cardiac auscultation is receiving less emphasis in teaching and practise [six]. Some technologies have tried and failed to address this limitation, such as audio CDs, websites, and mannequins, since none of these are able to accost the real needs of today: the mass didactics and certification of auscultation skills, allowing 500 repetitions per type of cardiac murmur, equally defended by Barret et al. [seven]. The effect of all of this is that cardiac auscultation has no structured teaching in three fourths of American internal medicine programs and two-thirds of cardiology programs [eight]. This will inevitably lead to poor practice and teaching of this technique at all levels of preparation. Although not besides documented, the same process of attrition is probably affecting the other cognitive skills of bedside exam [nine–11].

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Rheumatic Fever and Rheumatic Centre Affliction

L. Guilherme , ... J. Kalil , in The Heart in Rheumatic, Autoimmune and Inflammatory Diseases, 2017

2.6 Boosted Assessment

The stethoscope is commonly the simply noninvasive tool available to doctors in depression-income countries or in remote locations, where the RF and RHD are more prevalent. Nonetheless, the detection frequency is usually low. Doppler echocardiography has shown to exist more than sensitive and specific than cardiac auscultation in the early detection of RF and RHD, as shown in some studies in Africa and other parts of the world [96].

After the showtime episode of carditis, cardiac auscultation may fail to identify murmurs in up to one-third of cases. These children can progress to rheumatic valve disease in the following years. A written report conducted by highly trained clinicians in New Zealand showed that the clinical diagnosis of heart valve lesions, even among cardiologists, is often inaccurate [117]. Consequently, it is unlikely that the accuracy of clinical diagnosis by the medical customs in other countries is more reliable if echocardiographic criteria are not used.

Many cases of ARF are clinically silent and occur in asymptomatic children without cardiac murmurs; this fact suggests that echocardiographic screening is desirable to amend the identification of new cases and thus initiate early on secondary prevention measures. Since 2004, the WHO has recommended echocardiography screening in loftier-prevalence regions.

Marijon et al. (2007) conducted a portable echocardiography written report in school children in Mozambique and Kingdom of cambodia that showed college detection rates for RHD than for auscultation [118,119]. The prevalence of RHD identified early was and so documented in several studies around the world. The highest cited prevalence was among children of school age in the land of Tongo (three.3%), followed by Mozambique (3.0%), Kingdom of cambodia (2.2%), Australian Aborigines (ii.2%), Zaire (one.4%), and Republic of zambia (1.2%), every bit well equally a prevalence of 6.7% in Vietnam and nearly x% in a region of Brazil [117,118,120–123].

Mitral valvulitis is the nigh characteristic component of RHD. It is frequently associated with regurgitation. The aortic valvulitis is less mutual and is normally associated with mitral valve disease. The pulmonary and tricuspid valves are rarely involved. Remainder valve damage is a major concern in patients with RF and can cause intractable heart failure, often requiring surgical intervention.

The prevalence of RHD in asymptomatic patients as detected by Doppler echocardiography has not been well estimated, and tin can vary from 0% to 53% (weight pooled prevalence is around 16.8–xviii.1%) depending on the echocardiography criteria used [73]. Information technology is possible through early on detection to begin secondary prophylaxis and prevent these children from recurrent infections, thus improving prognosis.

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