A basic investigation into the optimization of cylindrical tubes used as acoustic stethoscopes for auscultation in COVID-19 diagnosis.

During the COVID-19 outbreak, the auscultation of heart and lung sounds has played an important role in the comprehensive diagnosis and real-time monitoring of confirmed cases. With clinicians wearing protective clothing in isolation wards, a potato chip tube stethoscope, which is a secure and flexible substitute for a conventional stethoscope, has been used by Chinese medical workers in the first-line treatment of COVID-19. In this study, an optimal design for this simple cylindrical stethoscope is proposed based on the fundamental theory of acoustic waveguides. Analyses of the cutoff frequency, sound power transmission coefficient, and sound wave propagation in the uniform lossless tube provide theoretical guidance for selecting the geometric parameters for this simple cylindrical stethoscope. A basic investigation into the auscultatory performances of the original tube and the optimal tube with proposed dimensions was conducted both in a semi-anechoic chamber and in a quiet laboratory. Both experimental results and front-line doctors' clinical feedback endorse the proposed theoretical optimization.

Artificial intelligence accuracy in detecting pathological breath sounds in children using digital stethoscopes.

BACKGROUND: Manual auscultation to detect abnormal breath sounds has poor inter-observer reliability. Digital stethoscopes with artificial intelligence (AI) could improve reliable detection of these sounds. We aimed to independently test the abilities of AI developed for this purpose. METHODS: One hundred and ninety two auscultation recordings collected from children using two different digital stethoscopes (Clinicloud™ and Littman™) were each tagged as containing wheezes, crackles or neither by a pediatric respiratory physician, based on audio playback and careful spectrogram and waveform analysis, with a subset validated by a blinded second clinician. These recordings were submitted for analysis by a blinded AI algorithm (StethoMe AI) specifically trained to detect pathologic pediatric breath sounds. RESULTS: With optimized AI detection thresholds, crackle detection positive percent agreement (PPA) was 0.95 and negative percent agreement (NPA) was 0.99 for Clinicloud recordings; for Littman-collected sounds PPA was 0.82 and NPA was 0.96. Wheeze detection PPA and NPA were 0.90 and 0.97 respectively (Clinicloud auscultation), with PPA 0.80 and NPA 0.95 for Littman recordings. CONCLUSIONS: AI can detect crackles and wheeze with a reasonably high degree of accuracy from breath sounds obtained from different digital stethoscope devices, although some device-dependent differences do exist.

Should the ultrasound probe replace your stethoscope? A SICS-I sub-study comparing lung ultrasound and pulmonary auscultation in the critically ill.

BACKGROUND: In critically ill patients, auscultation might be challenging as dorsal lung fields are difficult to reach in supine-positioned patients, and the environment is often noisy. In recent years, clinicians have started to consider lung ultrasound as a useful diagnostic tool for a variety of pulmonary pathologies, including pulmonary edema. The aim of this study was to compare lung ultrasound and pulmonary auscultation for detecting pulmonary edema in critically ill patients. METHODS: This study was a planned sub-study of the Simple Intensive Care Studies-I, a single-center, prospective observational study. All acutely admitted patients who were 18 years and older with an expected ICU stay of at least 24 h were eligible for inclusion. All patients underwent clinical examination combined with lung ultrasound, conducted by researchers not involved in patient care. Clinical examination included auscultation of the bilateral regions for crepitations and rhonchi. Lung ultrasound was conducted according to the Bedside Lung Ultrasound in Emergency protocol. Pulmonary edema was defined as three or more B lines in at least two (bilateral) scan sites. An agreement was described by using the Cohen κ coefficient, sensitivity, specificity, negative predictive value, positive predictive value, and overall accuracy. Subgroup analysis were performed in patients who were not mechanically ventilated. RESULTS: The Simple Intensive Care Studies-I cohort included 1075 patients, of whom 926 (86%) were eligible for inclusion in this analysis. Three hundred seven of the 926 patients (33%) fulfilled the criteria for pulmonary edema on lung ultrasound. In 156 (51%) of these patients, auscultation was normal. A total of 302 patients (32%) had audible crepitations or rhonchi upon auscultation. From 130 patients with crepitations, 86 patients (66%) had pulmonary edema on lung ultrasound, and from 209 patients with rhonchi, 96 patients (46%) had pulmonary edema on lung ultrasound. The agreement between auscultation findings and lung ultrasound diagnosis was poor (κ statistic 0.25). Subgroup analysis showed that the diagnostic accuracy of auscultation was better in non-ventilated than in ventilated patients. CONCLUSION: The agreement between lung ultrasound and auscultation is poor. TRIAL REGISTRATION: NCT02912624. Registered on September 23, 2016.

Mucoepidermoid carcinoma of the bronchus: a rare early diagnosis.

Salivary gland tumours of the tracheobronchial tree are rare and early diagnosis in T1 stage is further rare. We report a case of a young 21-year-old male medical student diagnosed and treated for the same prompted by a detailed respiratory examination.

[Lung auscultation in the 21th century]. / La auscultación pulmonar en el siglo 21.

Lung auscultation is an essential part of the physical examination for diagnosing respiratory diseases. The terminology standardization for lung sounds, in addition to advances in their analysis through new technologies, have improved the use of this technique. However, traditional auscultation has been questioned due to the limited concordance among health professionals. Despite the revolu tionary use of new diagnostic tools of imaging and lung function tests allowing diagnostic accuracy in respiratory diseases, no technology can replace lung auscultation to guide the diagnostic process. Lung auscultation allows identifying those patients who may benefit from a specific test. Moreover, this technique can be performed many times to make clinical decisions, and often with no need for- complicated and sometimes unavailable tests. This review describes the current state-of-the-art of lung auscultation and its efficacy based on the current respiratory sound terminology. In addition, it describes the main evidence on respiratory sound concordance studies among health professionals and its objective analysis through new technology.

The reliability and validity of cervical auscultation in the diagnosis of dysphagia: a systematic review.

OBJECTIVE: To systematically review the available evidence for the reliability and validity of cervical auscultation in diagnosing the several aspects of dysphagia in adults and children suffering from dysphagia. DATA SOURCES: Medline (PubMed), Embase and the Cochrane Library databases. REVIEW METHODS: The systematic review was carried out applying the steps of the PRISMA-statement. The methodological quality of the included studies were evaluated using the Dutch 'Cochrane checklist for diagnostic accuracy studies'. RESULTS: A total of 90 articles were identified through the search strategy, and after applying the inclusion and exclusion criteria, six articles were included in this review. In the six studies, 197 patients were assessed with cervical auscultation. Two of the six articles were considered to be of 'good' quality and three studies were of 'moderate' quality. One article was excluded because of a 'poor' methodological quality. Sensitivity ranges from 23%-94% and specificity ranges from 50%-74%. Inter-rater reliability was 'poor' or 'fair' in all studies. The intra-rater reliability shows a wide variance among speech language therapists. CONCLUSION: In this systematic review, conflicting evidence is found for the validity of cervical auscultation. The reliability of cervical auscultation is insufficient when used as a stand-alone tool in the diagnosis of dysphagia in adults. There is no available evidence for the validity and reliability of cervical auscultation in children. Cervical auscultation should not be used as a stand-alone instrument to diagnose dysphagia.

Manipulation of cognitive load variables and impact on auscultation test performance.

Health profession educators have identified auscultation skill as a learning need for health professional students. This article explores the application of cognitive load theory (CLT) to designing cardiac and respiratory auscultation skill instruction for senior-level undergraduate nursing students. Three experiments assessed student auscultation performance following instructional manipulations of the three primary components of cognitive load: intrinsic, extraneous, and germane load. Study 1 evaluated the impact of intrinsic cognitive load by varying the number of diagnoses learned in one instruction session; Study 2 evaluated the impact of extraneous cognitive load by providing students with single or multiple examples of diagnoses during instruction; and Study 3 evaluated the impact of germane cognitive load by employing mixed or blocked sequences of diagnostic examples to students. Each of the three studies presents results that support CLT as explaining the influence of different types of cognitive processing on auscultation skill acquisition. We conclude with a discussion regarding CLT's usefulness as a framework for education and education research in the health professions.

Developing a reference of normal lung sounds in healthy Peruvian children.

PURPOSE: Lung auscultation has long been a standard of care for the diagnosis of respiratory diseases. Recent advances in electronic auscultation and signal processing have yet to find clinical acceptance; however, computerized lung sound analysis may be ideal for pediatric populations in settings, where skilled healthcare providers are commonly unavailable. We described features of normal lung sounds in young children using a novel signal processing approach to lay a foundation for identifying pathologic respiratory sounds. METHODS: 186 healthy children with normal pulmonary exams and without respiratory complaints were enrolled at a tertiary care hospital in Lima, Peru. Lung sounds were recorded at eight thoracic sites using a digital stethoscope. 151 (81%) of the recordings were eligible for further analysis. Heavy-crying segments were automatically rejected and features extracted from spectral and temporal signal representations contributed to profiling of lung sounds. RESULTS: Mean age, height, and weight among study participants were 2.2 years (SD 1.4), 84.7 cm (SD 13.2), and 12.0 kg (SD 3.6), respectively; and, 47% were boys. We identified ten distinct spectral and spectro-temporal signal parameters and most demonstrated linear relationships with age, height, and weight, while no differences with genders were noted. Older children had a faster decaying spectrum than younger ones. Features like spectral peak width, lower-frequency Mel-frequency cepstral coefficients, and spectro-temporal modulations also showed variations with recording site. CONCLUSIONS: Lung sound extracted features varied significantly with child characteristics and lung site. A comparison with adult studies revealed differences in the extracted features for children. While sound-reduction techniques will improve analysis, we offer a novel, reproducible tool for sound analysis in real-world environments.

Diagnostic value of chest ultrasound after cardiac surgery: a comparison with chest X-ray and auscultation.

OBJECTIVE: Chest auscultation and chest x-ray commonly are used to detect postoperative abnormalities and complications in patients admitted to intensive care after cardiac surgery. The aim of the study was to evaluate whether chest ultrasound represents an effective alternative to bedside chest x-ray to identify early postoperative abnormalities. DESIGN: Diagnostic accuracy of chest auscultation and chest ultrasound were compared in identifying individual abnormalities detected by chest x-ray, considered the reference method. SETTING: Cardiac surgery intensive care unit. PARTICIPANTS: One hundred fifty-one consecutive adult patients undergoing cardiac surgery. INTERVENTIONS: All patients included were studied by chest auscultation, ultrasound, and x-ray upon admission to intensive care after cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Six lung pathologic changes and endotracheal tube malposition were found. There was a highly significant correlation between abnormalities detected by chest ultrasound and x-ray (k = 0.90), but a poor correlation between chest auscultation and x-ray abnormalities (k = 0.15). CONCLUSIONS: Chest auscultation may help identify endotracheal tube misplacement and tension pneumothorax but it may miss most major abnormalities. Chest ultrasound represents a valid alternative to chest x-ray to detect most postoperative abnormalities and misplacements.

UK student midwives' theoretical knowledge, confidence, and experience of intermittent auscultation of the fetal heart rate during labour: An online cross-sectional survey.

AIM: This study aimed to explore student midwives' theoretical knowledge of intrapartum intermittent auscultation, their confidence in, and their experience of this mode of fetal monitoring. DESIGN AND SETTING: An online cross-section survey with closed and open questions. Descriptive statistics were used to analyse participants' intermittent auscultation knowledge, confidence, and experience. Reflexive thematic analysis was used to identify patterns within the free text about participants' experiences. PARTICIPANTS: Undergraduate midwifery students (n = 303) from Nursing and Midwifery Council-approved educational institutions within the United Kingdom. FINDINGS: Most participants demonstrated good theoretical knowledge. They had witnessed the technique being used in clinical practice, and when performed, the practice was reported to be in line with national guidance. In closed questions, participants reported feeling confident in their intermittent auscultation skills; however, these data contrasted with free-text responses. CONCLUSION: This cross-sectional survey found that student midwives possess adequate knowledge of intermittent auscultation. However, reflecting individual clinical experiences, their confidence in their ability to perform intermittent auscultation varied. A lack of opportunity to practice intermittent auscultation, organisational culture, and midwives' preferences have caused student midwives to question their capabilities with this essential clinical skill, leaving some with doubt about their competency close to registration.

Revitalizing a vital sign: improving detection of tachypnea at primary triage.

STUDY OBJECTIVE: This study evaluates the accuracy of emergency department (ED) triage respiratory rate measurement using the usual care method and a new electronic respiratory rate sensor (BioHarness, Zephyr Technology Corp.), both compared to a criterion standard measurement. METHODS: This is a cross-sectional study with convenience sampling conducted in an urban academic adult ED, including 3 separate respiratory rate measurements performed at ED triage: usual care measurement, electronic BioHarness measurement, and criterion standard measurement. The criterion standard measurement used was defined by the World Health Organization as manual observation or auscultation of respirations for 60 seconds. The resultant usual care and BioHarness measurements were compared with the criterion standard, evaluating accuracy (sensitivity and specificity) for detecting tachypnea, as well as potential systematic biases of usual care and BioHarness measurements using a Bland Altman analysis. RESULTS: Of 191 analyzed patients, 44 presented with tachypnea (>20 breaths/min). Relative to criterion standard measurement, usual care measurement had a sensitivity of 23% (95% confidence interval [CI] 12% to 37%) and specificity of 99% (95% CI 97% to 100%) for tachypnea, whereas BioHarness had a sensitivity of 91% (95% CI 80% to 97%) and specificity of 97% (95% CI 93% to 99%) for tachypnea. Usual care measurements clustered around respiratory rates of 16 and 18 breaths/min (n=144), with poor agreement with criterion standard measurement. Conversely, BioHarness measurement closely tracked criterion standard values over the range of respiratory rates. CONCLUSION: Current methods of respiratory rate measurement at ED triage are inaccurate. A new electronic respiratory rate sensor, BioHarness, has significantly greater sensitivity for detecting tachypnea versus usual care method of measurement.

[Diagnosis and classification of mitral valve prolapse in children and adolescents].

We examined 1734 children and adolescents with admittance diagnosis mitral valve prolapse (MVP) and confirmed its presence using accepted Framingham criteria in 32.3% of cases. Reason for overdiagnosis in other cases was incorrect interpretation of auscultation or echocardiography data. Most often MVP was familial with recessive or dominant inheritance according to genealogical analysis. Contrary to MVP in adults children and adolescents commonly had no myxomatous transformation of valves. Taking into account constitutional and physiological peculiarities of the body in children and adolescents we distinguished two forms of MVP characteristic for this age: MVP as a variant of asthenic constitution and physiological MVP. Both forms are widely spread and represent normal states for juvenile population.

Respiratory sound classification for crackles, wheezes, and rhonchi in the clinical field using deep learning.

Auscultation has been essential part of the physical examination; this is non-invasive, real-time, and very informative. Detection of abnormal respiratory sounds with a stethoscope is important in diagnosing respiratory diseases and providing first aid. However, accurate interpretation of respiratory sounds requires clinician's considerable expertise, so trainees such as interns and residents sometimes misidentify respiratory sounds. To overcome such limitations, we tried to develop an automated classification of breath sounds. We utilized deep learning convolutional neural network (CNN) to categorize 1918 respiratory sounds (normal, crackles, wheezes, rhonchi) recorded in the clinical setting. We developed the predictive model for respiratory sound classification combining pretrained image feature extractor of series, respiratory sound, and CNN classifier. It detected abnormal sounds with an accuracy of 86.5% and the area under the ROC curve (AUC) of 0.93. It further classified abnormal lung sounds into crackles, wheezes, or rhonchi with an overall accuracy of 85.7% and a mean AUC of 0.92. On the other hand, as a result of respiratory sound classification by different groups showed varying degree in terms of accuracy; the overall accuracies were 60.3% for medical students, 53.4% for interns, 68.8% for residents, and 80.1% for fellows. Our deep learning-based classification would be able to complement the inaccuracies of clinicians' auscultation, and it may aid in the rapid diagnosis and appropriate treatment of respiratory diseases.

Hemopneumothorax detection through the process of artificial evolution - a feasibility study.

BACKGROUND: Tension pneumothorax is one of the leading causes of preventable death on the battlefield. Current prehospital diagnosis relies on a subjective clinical impression complemented by a manual thoracic and respiratory examination. These techniques are not fully applicable in field conditions and on the battlefield, where situational and environmental factors may impair clinical capabilities. We aimed to assemble a device able to sample, analyze, and classify the unique acoustic signatures of pneumothorax and hemothorax. METHODS: Acoustic data was obtained with simultaneous use of two sensitive digital stethoscopes from the chest wall of an ex-vivo porcine model. Twelve second samples of acoustic data were obtained from the in-house assembled digital stethoscope system during mechanical ventilation. The thoracic cavity was injected with increasing volumes of 200, 400, 600, 800, and 1000 ml of air or saline to simulate pneumothorax and hemothorax, respectively. The data was analyzed using a multi-objective genetic algorithm that was used to develop an optimal mathematical detector through the process of artificial evolution, a cutting-edge approach in the artificial intelligence discipline. RESULTS: The in-house assembled dual digital stethoscope system and developed genetic algorithm achieved an accuracy, sensitivity and specificity ranging from 64 to 100%, 63 to 100%, and 63 to 100%, respectively, in classifying acoustic signal as associated with pneumothorax or hemothorax at fluid injection levels of 400 ml or more, and regardless of background noise. CONCLUSIONS: We present a novel, objective device for rapid diagnosis of potentially lethal thoracic injuries. With further optimization, such a device could provide real-time detection and monitoring of pneumothorax and hemothorax in battlefield conditions.

A Multimethod Improvement Project to Strengthen Intermittent Auscultation Practice Among Nurse-Midwives and Nurses.

INTRODUCTION: Intermittent auscultation (IA) is an accepted standard of care for intrapartum fetal assessment for low-risk individuals and is the exclusive method used to monitor fetal status in birth centers. However, there are conflicting national guidelines for practice and skill training. As a result, IA technique and skills vary across the perinatal care workforce, with many health care providers receiving no or minimal formal training. This article describes the design, implementation, and evaluation of a quality improvement program aimed at strengthening the IA skills of nurse-midwives and nurses. PROCESS: The project was implemented in a multisite network of freestanding birth centers and involved clinical practice guideline development, simulation-based training, audit and feedback, in-person training, and electronic health record configuration. OUTCOMES: The training resulted in self-reported increases in knowledge in all areas assessed. The integrated quality improvement initiative resulted in substantial improvements in consistency of practice and documentation. DISCUSSION: Policy change was not sufficient to improve use of IA, a nuanced skill that many midwives and nurses have limited exposure to in basic education programs and hospital-based clinical practice. Clinical improvement was possible when the policy change was accompanied by a comprehensive training and implementation strategy including interactive, simulation-based learning, audit and feedback, and an electronic health record configuration that better reflected the documentation standards.

[Evaluation of the use of a simulation software in the learning of cardiopulmonary auscultation in undergraduate medical students]. / Evaluation de l'utilisation d'un logiciel de simulation dans l'apprentissage de l'auscultation cardio-pulmonaire chez les étudiants en premier cycle d'études médicales.

INTRODUCTION: Medsounds™ software allows to create an auscultation learning platform, by providing real pre-recorded cardiopulmonary sounds on virtual chests. The study aimed at comparing the skills in cardiopulmonary auscultation between students who benefited from this platform and students who did not have access to it. METHODS: A controlled trial was conducted with 2nd year medical students randomised into three groups. Groups A, B and C received 10 h of cardiopulmonary clinical training. In addition, group B benefited from an online access to the educative platform, and group C had a demonstration of the platform during their clinical training, then an online access. The main outcome was a 3-point multiple-choice questionnaire based on 2 original case vignettes about the description of cardiopulmonary sounds. The secondary outcome was the faculty exam on high-fidelity cardiopulmonary simulator. RESULTS: Groups A and B included 127 students, and group C 117. Students in group C had a significantly higher score than those in group A (1.72/3 versus 1.48/3; p = 0.02), without difference between the groups B and C. Students who actually had a demonstration of the platform and used it at home had a higher score than those who did not use it (1.87 versus 1.51; p = 0.01). Students who had a demonstration of the platform before using it performed a better pulmonary examination on high-fidelity simulators. CONCLUSION: The supervised use of an online auscultation simulation software in addition to the traditional clinical training seems to improve the auscultation performances of undergraduated medical students.

Who's counting? Assessing the effects of a simulation-based training intervention on the accuracy of neonatal heart rate auscultation.

OBJECTIVE: To determine if simulation-based medical education could improve pediatric residents' ability to accurately assess neonatal heart rate via auscultation. STUDY DESIGN: Primary outcomes included heart rate accuracy and Neonatal Resuscitation Program (NRP) group accuracy, defined as whether a heart rate estimation fell in the appropriate NRP algorithm group. Pediatric residents completed a pre-assessment and then participated in a simulation training intervention on high-fidelity manikins. Residents completed a post-assessment 1 month later. RESULTS: Heart rate estimates from 21 pediatric residents showed improved overall heart rate accuracy and NRP group accuracy from 53.6 to 78.7% (p < 0.0001) and 68.3 to 80% (p = 0.0002), respectively. Residents were more likely to overestimate low heart rates and underestimate high heart rates. CONCLUSION: Heart rate simulation-based training significantly improved residents' ability to assess heart rate on high-fidelity neonatal manikins. Providers participating in NRP may benefit by receiving heart rate skills assessment-focused training during an NRP provider course.

Comparative study on auscultatory and oscillometric methods of ambulatory blood pressure measurements in adult patients.

BACKGROUND: Ambulatory blood pressure (BP) monitors measure BP by oscillometric (Osc) or auscultatory (Aus) methods. In this study, we aimed to compare the values obtained by BP measurement methods in the ambulatory blood pressure monitoring (ABPM) device that can take measurements using both the methods, factors influencing these values, and their relevancy in obtaining valid measurement percentages. METHODS: The study was conducted on 212 patients. BP values of these patients were measured with the Nissei DS-250 (Nihon Seimitsu Sokki Co. Ltd, Gunma, Japan) monitor capable of recording BP simultaneously by the Aus and the Osc methods. The cases, for which no records were obtained by any one of the two methods, were considered to have missing records. The impacts of age, sex, body mass index, and arm circumference on the valid BP measurement values were examined. RESULTS: The valid measurement percentage without any missing records obtained by the Osc method was 87.3 and 16% by the Aus method. The body mass index, age, and arm circumference did not affect this percentage. The 24-h BP measurement values were higher by the Osc method. The differences between both methods in systolic blood pressure and diastolic blood pressure were 3.8+/-4.6 and 2.3+/-2.7 mmHg, respectively. Although the Aus method yielded higher standard deviation values than the Osc method for systolic blood pressure, standard deviation values obtained by the Osc method were higher than those obtained by the Aus method for diastolic blood pressure. CONCLUSION: The percentage of obtaining valid measurements by the Osc method used in the Nissei DS-250 model ABPM device examined in this study is higher when compared with the Aus method. Therefore, while examining ABPM results, the Osc method may be preferable over the Aus method.

Lung and Heart Sounds Analysis: State-of-the-Art and Future Trends.

Lung sounds, which include all sounds that are produced during the mechanism of respiration, may be classified into normal breath sounds and adventitious sounds. Normal breath sounds occur when no respiratory problems exist, whereas adventitious lung sounds (wheeze, rhonchi, crackle, etc.) are usually associated with certain pulmonary pathologies. Heart and lung sounds that are heard using a stethoscope are the result of mechanical interactions that indicate operation of cardiac and respiratory systems, respectively. In this article, we review the research conducted during the last six years on lung and heart sounds, instrumentation and data sources (sensors and databases), technological advances, and perspectives in processing and data analysis. Our review suggests that chronic obstructive pulmonary disease (COPD) and asthma are the most common respiratory diseases reported on in the literature; related diseases that are less analyzed include chronic bronchitis, idiopathic pulmonary fibrosis, congestive heart failure, and parenchymal pathology. Some new findings regarding the methodologies associated with advances in the electronic stethoscope have been presented for the auscultatory heart sound signaling process, including analysis and clarification of resulting sounds to create a diagnosis based on a quantifiable medical assessment. The availability of automatic interpretation of high precision of heart and lung sounds opens interesting possibilities for cardiovascular diagnosis as well as potential for intelligent diagnosis of heart and lung diseases.

Investigation of the efficacy of colorimetric capnometry method used to verify the correct placement of the nasogastric tube.

OBJECTIVES: This present study was designed to determine the efficacy of the colorimetric capnometry method used to verify the correct placement of the nasogastric tube. METHODS: The present study comprised forty patients who had a nasogastric tube inserted and were being monitored in the adult intensive care unit. After the insertion of the nasogastric tube, 40 colorimetric capnometry and 40 auscultation measurements were performed. Auscultation and colorimetric capnometry results were compared with tube placement results confirmed radiologically. RESULTS: In the confirmation of the placement of the nasogastric tube, the consistency was 97.5% (p<0.05) between the colorimetric capnometry method and the radiological method, and 82.5% (p>0.05) between the auscultatory method and the radiological method. The oesophageal placement of the nasogastric tube was detected with the colorimetric capnometry method, but the gastric and duodenal insertions were not determined. While the sensitivity and specificity of the colorimetric capnometry method in determining the correct placement of the nasogastric tube were 1.00 and 0.667 respectively, those of the auscultatory method were 0.89 and 0.0 respectively. CONCLUSION: As a result, for the confirmation of the NGT placement, the colorimetric capnometry method is considered more reliable than the auscultatory method and is compatible with the radiological method. However, the colorimetric capnometry method is inadequate to distinguish between the gastric or duodenal insertion.