UPDATED: Medtronic touts studies of its devices to monitor patients following sedation

The Capnostream 20p patient monitor--Courtesy of Medtronic

Medtronic ($MDT) touted two studies demonstrating the benefits of its capnography patient monitoring offerings at the Anesthesiology annual meeting in San Diego.

Capnography is used to detect respiratory compromise following sedation by measuring the concentration of carbon dioxide in exhaled breath. Medtronic said the studies show the clinical benefits of its Integrated Pulmonary Index, which summarizes four vital sign trends (end-tidal carbon dioxide, pulse oximetry, respiratory rate and pulse rate) as a single number.

Capnography is the standard of care during sedation performed by anesthesiologists, but not when sedation is administered by proceduralists. Medtronic vice president of respiratory compromise market development David Giarracco said that procedures are not fundamentally different, and explained that the difference in medical practice stems from varying guidelines. Specifically, the American Society of Anesthesiology guidelines make capnography mandatory, he said. 

An observational study of 163 Japanese patients found the initial IPI index number was lower in patients who suffered a subsequent respiratory adverse event. A measure of oxygen saturation (which can be obtained using pulse oximeter) was also lower in the patients who had an adverse event, but the researchers determined that the IPI was a better predictor, Medtronic said in a release.

"It is critical that patients who are administered any type of sedation, from general anesthesia to procedural sedation, be carefully monitored for signs of respiratory compromise," said Dr. Hiroshi Morimatsu, director of the anesthesiology and resuscitology department at Okayama University Hospital in Japan. "Capnography monitoring can detect subtle changes in respiratory status and provide the earliest indication of airway compromise. The findings from this study provide further evidence of the necessity to use capnography, along with the Integrated Pulmonary Index, for postoperative patients, especially those with high risk of hypoventilation."

The study is an effort to build up the evidence base surrounding capnography and increase customer awareness, according to Giarracco. "All four of those IPI parameters give a more complete respiratory response profile of the patient," he said.  

Another study that modeled the cost-effectiveness of capnography determined that it results in savings of $123 per endoscopy procedure after one year because the technology prevents procedure terminations, unplanned hospital admissions and anesthesiology interventions. It assumed a capnography cost of $4,000 per monitor and $16 per procedure for disposables; pulse oximetry was assumed to have no cost. The researchers disclosed that they received consulting fees or salary from Medtronic.

Giarracco explained that the complex economic model used statistics and probabilities derived from prior research to arrive at its conclusion, and said the study found that the cost savings from reduced complications means that capnography using IPI pays for itself after 10 patients.    

"The findings presented today demonstrate the clinical benefits and potential cost savings capnography can provide across a broad spectrum of patients," said Dr. Michael Tarnoff, vice president and chief medical officer of the Medtronic's minimally invasive therapies group, in a statement. "These studies underscore Medtronic's commitment to reducing the growing burden of respiratory compromise across clinical settings to improve the health and care of patients."

Respiratory compromise begins with respiratory insufficiency and progresses to respiratory failure and then arrest. Medtronic says of the 13 million patients using patient-controlled analgesia each year, as many as 678,000 suffer from life threatening opioid-induced respiratory depression. Other risk factors include obesity and old age.  

Medtronic's Microstream capnography franchise consists of handheld and bedside monitors, disposables and components for third-party manufacturers. The device bigwig entered the arena via the $50 billion takeover of Covidien in January 2015.

- read the release

Special Report: 2013's top FDA approvals in med tech - Johnson & Johnson's Sedasys computer-assisted sedation system

Editor's Note: This article has been updated with comments from Medtronic vice president David Giarracco.