SEARCH · PubMed Health

Results for “STETHOSCOPE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMedDate not supplied

Use of the esophageal stethoscope in pediatric transports.

INTRODUCTION: Monitoring cardiac and respiratory function during helicopter transports can be difficult, so the authors devised a study of the esophageal stethoscope for pediatric patients. SETTING: The study was conducted at Pediflite in Tennessee, which transports between 250 to 300 pediatric patients every year. MATERIALS AND METHODS: A disposable esophageal stethoscope was used as an adjunct to other monitoring systems in intubated patients. Prior to transport, the stethoscope was placed orally by the respiratory therapist and advanced to the point where heart sounds are heard best, at which point breath sounds can also be heard clearly. The device's ear piece easily fit under the crew member's headphones, which block helicopter noise. Three sizes of stethoscope are available: a 6 French for patients 1 day to 4 years old, a 9 French for those 4 to 12 years old, and an 18 French for patients 12 years of age or older. RESULTS: The esophageal stethoscope was used in 55 patients ranging in age from newborn to 18 years. Eighteen of 55 (33%) had multiple trauma or closed head injury, and 14 of 55 (25%) suffered respiratory failure. The esophageal stethoscope proved to be easy to place, had a low risk of complications and allowed continuous access to breath sounds. In addition, the ability to hear heart tones was minimally affected by noise or vibration. CONCLUSION: Due to its ability to continuously monitor breath sounds, endotracheal tube obstruction or displacement can be rapidly detected by the esophageal stethoscope. Also, if there is failure of the cardiopulmonary monitor, heart sounds can be continuously monitored. The esophageal stethoscope is a simple but potentially valuable tool in pediatric and neonatal transports for monitoring respiratory and cardiac status.

Adolescent↗

PubMed1986

[Reliability of the ejection fraction determined with the nuclear stethoscope. Comparison with angiocardiography].

The purpose of this investigation was to compare the Ejection Fraction values simultaneously obtained with the Nuclear Stethoscope and with Cineangiography, in 25 patients (17M-8W) subjected to diagnostic cardiac catheterization. In all patients the determination of Ejection Fraction with the Nuclear Stethoscope always preceded the Cineangiography. Ejection Fraction values obtained with Nuclear Stethoscope change from 32 to 75%; those calculated with Cineangiography, between 18 and 88%. The average Ejection Fraction values obtained with Nuclear Stethoscope (59 +/- 13%) doesn't differ significantly from Cineangiography (59 +/- 21%). There was a direct relationship between Ejection Fraction determined by the Nuclear Stethoscope and Cineangiography (r = 0.93; p less than 0.001). In the obtained results the Authors point out that the Ejection Fraction with Nuclear Stethoscope gives assurance in most patients, although in some particular conditions Nuclear Stethoscope provides Ejection Fraction values which differ from those obtained with Cineangiography. They conclude that Nuclear Stethoscope, for its safe, repeating and simple application, is a methodology of useful employment for Ejection Fraction determination in the single patient, which allows a correct definition of the prognosis and a conforming therapeutic strategy.

Adolescent↗

PubMed2002

Stethoscope: a friend or an enemy?

CONTEXT: The stethoscope is a universal tool in the hospital that is in direct contact with many patients and can therefore be a vector in the dissemination of bacterial infections. OBJECTIVE: To research the presence of bacteria, fungi and yeast on the stethoscope diaphragm and the resistance of bacteria to antimicrobial drugs. DESIGN: Descriptive, prospective, non-controlled. SETTING: A tertiary care hospital. SAMPLE: Samples were taken randomly from 300 stethoscopes employed by medical staff (medical residents, medical students, nurses and nursing school students) and other sectors of the hospital. MAIN MEASUREMENTS: Three hundred stethoscope diaphragms used in several sectors of the hospital facilities by medical doctors (63 samples), medical residents (54 samples), medical students (106 samples), nursing school students (33 samples) and specific sectors (36 samples) were analyzed. Material was collected randomly. It was collected with the aid of a sterile swab moistened in physiological solution, inoculated into Brain Heart Infusion media and incubated in an oven for 24 to 48 hours. After this period, the samples were inoculated into blood agar, MacConkey agar and Sabouraud media and identified by Gram staining and biochemical assays. An assay to test bacteria sensitivity to antibiotics was also carried out by the Kirby-Bauer method. RESULTS: Eighty-seven percent of the analyzed stethoscopes were contaminated. Gram-positive cocci, yeasts, fungi and Gram-positive and negative bacilli were isolated. There was no significant association between the most predominant microorganisms and professional category. Staphylococcus aureus, Staphylococcus negative coagulase and Bacillus were significantly more frequent in relation to the presence of more than one microorganism on the stethoscope diaphragm. CONCLUSION: Stethoscopes presented a high rate of contamination and their use without precautions can spread nosocomial infections.

Chi-Square Distribution↗

PubMed1993

The Australian Incident Monitoring Study. The stethoscope: applications and limitations--an analysis of 2000 incident reports.

The first 2000 incidents reported to the Australian Incident Monitoring Study (AIMS) were analysed with respect to the role of the oesophageal or precordial stethoscope as a continuous monitor. There were 1099 of the 1256 incidents during general anaesthesia in which one might have been used in this way, but use was reported in only 65 cases (5%), predominantly during paediatric cases. In only one report, a cardiac arrest, was the stethoscope the first to detect the incident. In a theoretical analysis it was considered that the stethoscope, used on its own for continuous monitoring, could have detected 54% of the 1256 incidents (almost 25% before any potential for organ damage), had they been allowed to evolve. However, AIMS data suggest that the actual yield using a stethoscope as a continuous monitor may be much lower than this, and that even the use of a "mobile" stethoscope can not be relied upon to detect oesophageal or endobronchial intubation. These reports confirm that there is limited use of the stethoscope for continuous monitoring in current anaesthetic practice in Australia; it has been superseded by the sophisticated electronic monitors now available. However, in areas with limited resources continuous auscultation with a stethoscope remains a basic requirement.

Accidents↗

PubMed2004

[Ultrasound stethoscope in the rapid assessment of left ventricular systolic function and valvular regurgitation--personal experience].

BACKGROUND: Recent technological advances enabled miniaturization of echocardiographic machines and construction of portable "ultrasound stethoscopes", which enable rapid two-dimensional and color-Doppler imaging and supplement clinical examination of the heart. We present the results of systematic assessment of these devices in comparison with standard echocardiographic machines. METHODS: We prospectively examined with both ultrasound stethoscopes and standard echocardiographic machines 60 patients referred to our laboratory for routine echocardiographic examination. Image quality (score: 1 to 4; best to worst), accuracy in qualitative evaluation of valvular regurgitation and left ventricular function (ejection fraction) were directly compared. Color Doppler assessment of valvular regurgitation was graded on a standard four point scale. A two or more point difference was considered major. Ejection fraction was estimated (the ultrasound stethoscope is not equipped with appropriate software). RESULTS: Image quality was significantly worse in the case of ultrasound stethoscope (2.6 vs 2.1; p<0.0001). Major differences in the assessment of regurgitant jets were present in 3 cases (5%) (1 mitral and 2 tricuspid). The degree of agreement was good in the case of mitral and pulmonary regurgitation (kappa=0.61 and 0.74 respectively), very good in the case of aortic regurgitation (kappa=0.80) and moderate in the case of tricuspid regurgitation (kappa=0.48). The differences in the assessment of aortic and mitral regurgitant jets correlated with the image quality (p<0.05). A Bland-Altman graph comparing the results of ejection fraction assessment revealed good agreement between methods. CONCLUSIONS: Results of the systematic evaluation of the use of ultrasound stethoscopes in the rapid evaluation of left ventricular systolic function and valvular regurgitation. Although image quality achieved with the hand-held stethoscope was worse, nevertheless it was adequate for the purpose of performing rapid limited assessment of cardiac and valvular function.

Adult↗

PubMed1996

[Level of stethoscope contamination in the hospital environment].

The aim of this study was to determine the extent of the contamination of stethoscopes and their possible role in transmission of microorganisms. The stethoscopes of the medical doctors of the hospital of La Chaux-de-Fonds, Switzerland, were cultured and the date of the last cleaning recorded. 38 of the 62 stethoscopes surveyed were contaminated with microorganisms (61%). The majority of isolated organisms were gram-positive bacteria, primarily Staphylococcus species (89%). The cleaning of the stethoscopes was frequent for 32% of the doctors, rare for 46% and non-existent for 22%. After more than one day without cleaning of the stethoscope, the level of contamination rose from 0% to 69%. Stethoscope use may be an important factor in the spread of infectious agents, so that regular disinfection should be carried out (once a day at the very least).

Bacteriological Techniques↗

PubMed1988

Blinded comparison of an "ultrasound stethoscope" and standard echocardiographic instrument.

We evaluated blinded readings by a physician using a miniature real-time "ultrasound stethoscope" compared with a "standard" echo instrument used by an independent physician. Size of all four cardiac chambers, wall motion, all four valves, thickness of interventricular septum and left ventricular posterior wall, and pericardial effusion were assessed in 66 patients. Each physician estimated whether he had answered the referring question and gave a final diagnosis. The physician using the ultrasound stethoscope correctly assessed chamber size in 87 percent of cases, segmental left ventricular wall motion in 71 percent of segments studied, and wall thickness in 88 percent of cases, and the diagnosis by the ultrasound stethoscope agreed with that made by the standard instrument in 68 percent of cases. The physician with the ultrasound stethoscope detected structural valvular problems (eg, stenosis) in 70 percent of cases but only detected flow abnormalities (eg, regurgitation) in 14 percent of cases. We conclude that (1) an experienced echocardiographer using an ultrasound stethoscope can detect most structural abnormalities found by a standard echocardiographic instrument; (2) chamber size, valvular stenosis, and pericardial effusions were accurately assessed; (3) the ultrasound stethoscope cannot be used to detect valvular regurgitation; and (4) limitations include the lack of freeze-frame, M-mode, hard copy, and Doppler.

Adult↗

PubMedDate not supplied

[Measurement of the frequency response of several stethoscopes in common use. Consequences for cardiac and pulmonary auscultation].

We measured the frequency response of eight stethoscope membranes and of thirteen types of stethoscopes. Measurements were made in an anechoic chamber calculating the ratio between the intensity of a sinusoidal sound coming from a loud speaker and the intensity of the transmitted sound through the membrane of the stethoscope. Small membranes have a bandwidth (without attenuation or amplification) between 10 and 600 Hz while large membranes have a bandwidth twice the size (10-1200 Hz). This good result does not appear in the case of stethoscopes showing increasing attenuation versus frequency, with a mean value from -2.5 to -10.5 dB and variations of 10 dB in the range 50-1200 Hz which is the useful bandwidth for cardiac and pulmonary auscultation. By contrast, fidelity of the measured stethoscopes was good. Discussion of the results suggests modification of stethoscope design to eliminate faults of sound transmission and to elaborate a microphone sensor allowing an electric transmission.

Auscultation↗

PubMed1993

[Assessment of the background count to measure the left ventricular ejection fraction with a nuclear stethoscope].

The nuclear stethoscope is a newly developed device for monitoring left ventricular ejection fraction (EF) with a pair of cadmium telluride detector for both left ventricular count (first channel) and background count (second channel). Although it is useful for evaluating the cardiac function during exercise, the methodology of the calculation for distinguishing the net ventricular blood count from the background count has not been established yet. In order to establish a reasonable method to calculate EF, we measured EF using a nuclear stethoscope and conventional gated blood pool scintigraphy in 20 healthy volunteers. All subjects underwent two supine ergometer exercise tests consisting of the 3 stages for the nuclear stethoscope and blood pool scintigraphy. The EF was determined with the following three method for the nuclear stethoscope; 1) Cut-off level was fixed at 70% of first channel, 2) Cut-off level at 75%, 3) Cut-off level was determined by the background count obtained from second channel. There was a poor relationship between the EFs obtained from gated blood scintigraphy and the EFs from the nuclear stethoscope calculated by any of these method. Regarding the EF calculated using the background count, however, the delta values of EF between rest and any of the 3 stages during exercise correlated closely to those EF from blood scintigraphy. When we apply the EF-at-rest value obtained from blood pool scintigraphy to analysis with the nuclear stethoscope, the EFs of 3 stages indicated good correlation (Stage I r = 0.91, Stage II r = 0.82, Stage III r = 0.69).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2006

Effect of teaching and type of stethoscope on cardiac auscultatory performance.

BACKGROUND: Auscultation of the heart is a routine procedure. It is not known whether auscultatory skills can be improved by teaching or with the use of an advanced stethoscope. METHODS: This study was a randomized trial with a 2 x 2 factorial design. Seventy-two house officers were randomized to a simple or an advanced stethoscope and to a 4-hour course in auscultation or no course. The doctors auscultated 20 patients' hearts and categorized findings as normal or as one or more of 5 categories of heart diseases. Patients were selected such that 16 had a known heart disease as well as a corresponding murmur and 4 had no heart disease or murmur. Auscultatory performance was assessed as concordance with echocardiographic findings and interobserver variation. RESULTS: Doctors using the advanced stethoscope diagnosed 35% of the patients correctly, as compared with doctors using the simple stethoscope who did 33% of the patients (P = .27). Similarly, 34% of the patients were diagnosed correctly by doctors who had received teaching as compared with 33% of those who were by doctors who had received no teaching (P = .41). The kappa values were higher for doctors who had received teaching for aortic stenosis (0.43 vs 0.28, P = .004) and ventricular septum defect (0.07 vs 0.01, P = .003). There was no difference between groups for any other single murmur or for the detection of murmurs as such. CONCLUSION: Heart auscultation findings were in poor accordance with echocardiographic findings and had high interobserver variation. Neither outcome improved to any important extent with the subjects' use of an advanced stethoscope or attending of a course in heart auscultation.

Adult↗

PubMed2006

A fuzzy expert system design for analysis of body sounds and design of an unique electronic stethoscope (development of HILSA kit).

In this paper we have developed a fuzzy expert system (FES) for different sounds produced by different organs in the human body. We have also constructed a unique electronic stethoscope. The human body sounds produced by different organs like heart, lungs and intestine were analyzed. The doctor provided the data and relation between variables chosen for each organ sound. Using this information a rule base for fuzzy expert system was built. Such FES helps the medical doctor in arriving at appropriate decision in different difficult clinical situations. The examination of body sounds was done using conventional stethoscope (CS) and electronic stethoscope (ES), which was uniquely designed for this study. We have found that unique stethoscope developed by us is far superior to conventional stethoscope by its overall performance.

Algorithms↗

PubMed2006

Orientation of the stethoscope around the neck: a random phenomenon or an indicator of cerebral lateralisation? Cross-sectional survey.

This study aimed to determine whether the orientation of the stethoscope when placed around the neck by physicians is a random occurrence or if this represents a lateral preference. A cross-sectional questionnaire survey was conducted, recruiting 186 medical doctors of all grades from the University Hospital of Wales, Cardiff. Stethoscope orientation preference, and seven other measures of lateral preference (handedness, footedness, eyedness, earedness, hand clasping, arm folding, and leg crossing), were assessed. The percentage of right-type, left-type, and indifferent-type orientation for each of the eight lateral preferences was determined, and 60%, 35%, and 5% of participants demonstrated right, left, and indifferent stethoscope orientation types, respectively. Stethoscope orientation preference correlated with handedness, footedness, earedness, and hand-clasping, but not with eyedness, arm-folding, or leg-crossing. Stethoscope orientation preference is not a chance phenomenon and may be an expression of cerebral dominance.

Adult↗

PubMed1999

Bacterial contamination of hospital physicians' stethoscopes.

Because stethoscopes might be potential vectors of nosocomial infections, this study, conducted in a 450-bed general hospital, was devised to evaluate the bacterial contamination of stethoscopes; bacterial survival on stethoscope membranes; the kinetics of the bacterial load on stethoscope membranes during clinical use; and the efficacy of 70% alcohol or liquid soap for membrane disinfection. Among the 355 stethoscopes tested, 234 carried > or =2 different bacterial species; 31 carried potentially pathogenic bacteria. Although some bacteria deposited onto membranes could survive 6 to 18 hours, none survived after disinfection.

Bacteria↗

PubMed1992

Comparison of the acoustic properties of six popular stethoscopes.

This study evaluated stethoscope acoustics by using a sound frequency generator and an active artificial ear. Six popular, currently available stethoscopes were compared in their various modes involving bells, diaphragms, etc.: Littmann Classic II, Littmann Cardiology II, Littmann Master Cardiology, Hewlett-Packard Rappaport-Sprague, Tycos Harvey Triple Head, and Allen Medical Series 5A RPS Binaural. The transfer function was measured from 37.5-1000 Hz, the range where nearly all heart and lung sounds are found. Sound in the low-frequency range (37.5-112.5 Hz) was in most cases amplified by the bells and attenuated by the diaphragms; however, there were no significant differences. Both bells and diaphragms attenuated sound transmission in the high range, and this increased with frequency. The Tycos Harvey Triple Head ribbed diaphragm attenuated sound transmission to a significantly greater extent than the other diaphragms (P less than 0.01). The results show that the bell and diaphragm for a given stethoscope usually have different transmission characteristics, particularly at low frequencies. The Littmann Classic II is an exception. The Hewlett-Packard and Tycos Harvey stethoscopes showed the greatest differences in low frequency response between the bell and the diaphragm. While the differences found in sound transmission between stethoscopes were in most cases small, the Littmann Cardiology II, bell and diaphragm, appears to possess the best overall performance by this study design.

Acoustics↗

PubMed2000

The stethoscope in the Emergency Department: a vector of infection?

The purposes of this study were to determine whether microorganisms can be isolated from the membranes of stethoscopes used by clinicians and nurses, and to analyse whether or not the degree of bacterial colonization could be reduced with different cleaning methods. We designed a transversal before-after study in which 122 stethoscopes were examined. Coagulase negative staphylococci (which are also potentially pathogenic microorganisms) were isolated together with 13 other potentially pathogenic microorganisms, including S. aureus, Acinetobacter sp. and Enterobacter agglomerans. The most effective antiseptic was propyl alcohol. Analysis of the cleaning habits of the Emergency Department (ED) staff, showed that 45% cleaned the stethoscope annually or never. The isolation of potentially pathogenic microorganisms suggests that the stethoscope must be considered as a potential vector of infection not only in the ED but also in other hospital wards and out-patient clinics.

1-Propanol↗

PubMed2001

Survey of the use of oesophageal and precordial stethoscopes in current paediatric anaesthetic practice.

BACKGROUND: The aim of the study was to examine the use of oesophageal and precordial stethoscopes for monitoring in current paediatric anaesthetic practice in the UK and Ireland. METHODS: A postal survey of members of the Association of Paediatric Anaesthetist of Great Britain and Ireland was undertaken. RESULTS: One hundred and forty-five questionnaires were returned with a response rate of 67.4%. Some 35.2% of anaesthetists never use an oesophageal or precordial stethoscope and the majority of the remaining 64.8% use one in less than one-third of their practice. CONCLUSION: Use of the stethoscope as a continuous monitor has decreased and most anaesthetists feel it has been superseded by other monitoring. However, almost one-third of anaesthetists recorded critical incidents they had been involved with where an oesophageal or precordial stethoscope detected the incident early. Complications of these monitoring devices were rare and the main factors limiting their use was the presence of better monitoring, such as pulse oximetry and capnography, and lack of availability.

Anesthesia↗

PubMed1998

Esophageal stethoscope placement depth: its effect on heart and lung sound monitoring during general anesthesia.

UNLABELLED: Although the esophageal stethoscope has been used for many years, the effect of the depth of placement on the quality of the sounds obtained has never been investigated. The amplitude and frequency characteristics of the first and second heart sound and of inspiratory and expiratory breath sounds were determined at various stethoscope depths (from the distal tip) in 17 healthy anesthetized adults. The amplitude for each type of sound varied markedly with depth. Maximal amplitude for S1 was at 34 +/- 3 cm, for S2 at 27 +/- 2 cm, for inspiratory breath sound at 28 +/- 2 cm, and for expiratory breath sound at 26 +/- 2 cm. There was a positive linear correlation between the depth of maximal amplitude of these sounds and patient height. Peak frequency, in general, did not change with depth. We conclude that investigators should measure and document depth when performing studies involving the esophageal stethoscope. IMPLICATIONS: Analysis of sound from the esophageal stethoscope at various depths reveals that placement depth greatly affects the sounds. A depth of 28-32 cm is recommended for clinical use; S1, S2, and inspiratory and expiratory sounds have a high amplitude in that range.

Adolescent↗

PubMed2004

Development of an electro-stethoscope system and design of an optimum filter based on tissue sound transmission for noninvasive early diagnosis of malfunction of an implanted mechanical total artificial heart.

Early diagnosis of the malfunction of a mechanical artificial heart implanted in a patient who has been discharged from hospital is very important. We have developed an electro-stethoscope system that enables the malfunction of an artificial heart to be detected from the analysis of sound signals from the artificial heart. The sound data can be transmitted to a hospital via a mobile telephone or the Internet, so that doctors can examine the condition of the artificial heart. The optimum frequency characteristics of a low-pass filter for the elimination of ambient sound through the electro-stethoscope casing were obtained by simulating sound transmission through tissue. We evaluated the usefulness of the electro-stethoscope system using a goat in which an undulation pump total artificial heart had been implanted. A frequency analysis of the sound signal provided information on the degree of degradation of each mechanical component of the artificial heart. The results of this study showed that the electro-stethoscope system is useful for the early detection of the malfunction of an artificial heart at home, and that the use of the system contributes to improvement in the quality of life of patients.

Animals↗