Waveform and Spectral Characteristics of Perioperative Wheezing

• Conditions: Respiratory Sounds; Thoracic Surgery

• Registration Number: NCT04873882
• Lead Sponsor: University of Virginia

Brief Summary

With the aid of computerized sound analysis, digital acoustic monitoring could provide a more sensitive, specific, and quantifiable indicator for perioperative respiratory abnormalities including wheezing. It is probable that the digital stethoscope has utility in the detection, monitoring, and resolution following treatment of acoustic changes characteristic of turbulent respiratory gas flow due to wheezing and/or the incomplete resolution of atelectasis following the re-initiation of ventilation in a collapsed lung.

Detailed Description

Anesthesiologists still rely on use of a conventional stethoscope to detect abnormal breath sounds during and after surgery - this process is labor intensive, intermittent, relies on human experience and thus is highly subjective. In fact, even for the most basic assessments, e.g. endobronchial intubation, human auscultation is unreliable.1 Digital stethoscopes are able to both amplify and digitize airway sounds and also provide a mechanism to record and analyze them for features undetectable by a human. Several small, pilot studies have shown that acoustic waveforms from the lungs produce characteristic spectral patterns in specific pulmonary pathophysiologic states. At this time, there are no studies that examine the acoustic patterns specific to perioperative wheezing or lung re-expansion. With the aid of computerized sound analysis, digital acoustic monitoring could provide a more sensitive, specific, and quantifiable indicator for perioperative respiratory abnormalities including wheezing. It is probable that the digital stethoscope has utility in the detection and monitoring of acoustic changes characteristic of turbulent respiratory gas flow due to wheezing and/or the incomplete resolution of atelectasis following the re-initiation of ventilation in a collapsed lung. In addition, treatment of perioperative wheezing with an inhaled bronchodilator may lead to resolution of wheezing and this response to treatment may also be monitored using waveform and spectral characteristics of the acoustic patterns from the digital stethoscope.

Study Timeline

• Study Start: 2019-12-16
• Status Verified: 2021-04
• Study First Submitted: 2021-04-26
• Study First Submitted QC: 2021-04-29
• Last Update Submitted: 2021-04-29
• Study First Posted: 2021-05-05
• Last Update Posted: 2021-05-05
• Primary Completion: 2021-08-27
• Study Completion: 2021-08-27

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

Patients scheduled for either:

1. open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring one-lung ventilation
2. abdominal surgery with a known history of chronic obstructive pulmonary disease (as documented in the electronic medical record)

Exclusion Criteria

• Emergency surgery
• surgery requiring the use of transesophageal echocardiography
• refusal of informed consent
• pregnancy
• esophageal surgery
• lung transplantation
• contraindications for placement of esophageal stethoscope including esophageal varices strictures, motility disorders, diverticula or a history of prior esophageal injury or surgery
• age less than 18 years old
• prisoner

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Spectral Waveform Analysis to discriminate between wheezing and not wheezing based on specific frequency bands	Duration of the operation while the esophageal stethoscope is in place, an average of 3 hours	Comparison of the spectral waveforms to determine the specific frequency bands associated with wheezing and non-wheezing

Secondary Outcome Measures

Name	Time	Method
Spectral waveform analysis associated with ventilatory parameters	Duration of the operation while the esophageal stethoscope is in place, an average of 3 hours	Ventilatory parameters including respiratory rate, tidal volume, and airway pressures that were recorded during the case will be compared with the spectral waveforms to determine the specific frequency bands associated with ventilatory parameters during one-lung ventilation and two-lung ventilation

Trial Locations

Locations (1)

University of Virginia; 🇺🇸 Charlottesville, Virginia, United States