For Release: April 11, 2000
Contact: Kymberly Lynch, ACCP
847/498-8341
[email protected]
SIMPLE VENTILATORY SUPPORT SUCCESSFULLY RESTORES OXYGEN LEVELS/ REDUCES CHANCE OF DEATH
By using a simple, noninvasive procedure for ventilatory support, German clinical investigators successfully restored systemic oxygen levels and significantly reduced the chance of death in postsurgical patients who had gone into acute respiratory failure following removal from mechanical ventilation. The research appears in the April issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians.
Detlef Kindgen-Milles, M.D., along with four associates, from the Department of Clinical Anesthesiology, Heinrich-Heine-University, Dusseldorf, Germany, used nasal continuous positive airway pressure (nCPAP) almost continuously on 20 consecutive patients in the intensive care unit (ICU). Within one hour, nCPAP substantially increased systemic blood oxygenation. All patients had undergone severe thoracic, abdominal, or thoracoabdominal surgery. After an operation, a period of mechanical ventilation is often needed when a muscle relaxant is included as part of the general anesthetic.
In mechanical ventilation, the air is delivered to the patient's lungs via a tube inserted in the windpipe. After the tube is removed, should acute respiratory failure occur, reintubation can increase the mortality rate of the patient sevenfold.
"Avoiding endotracheal intubation and mechanical ventilation by noninvasive ventilatory support can significantly reduce infectious complications, cut the length of ICU stay, and reduce mortality in patients with acute respiratory failure," said Dr. Kindgen-Milles. "All 20 of our patients met the predefined criteria for reintubation because of severe respiratory failure following their removal from mechanical ventilation."
During the study, only two patients had to be reintubated for reasons unrelated to oxygenation or ventilation, according to the authors.
The investigators said that reintubation was avoided by application of nCPAP by face mask. In nCPAP, patients wear a mask over their nose. Air from a compressor is forced through the mask into the nasal passages, the airway, and down into the lungs.
During their first day, nCPAP was never stopped for more than 30 minutes. Later, to enhance nursing care, the clinicians allowed patients to have three to four periods per day without nCPAP of less than 30 minutes.
"Our earlier use of intermittent CPAP could not stop or reverse the continuing deficiency in blood oxygenation, or hypoxemia, so a continuous form of therapy was needed," said Dr. Kindgen-Milles.
According to the authors, institution of nCPAP with a continuous flow of oxygen is simple and can be started within minutes, not only in the ICU, but also on intermediate care wards. They believe a trial of nCPAP can be initiated in almost any patient with hypoxemic respiratory failure prior to performing endotracheal intubation. This is especially true when the patient does not have a serious excess of carbon dioxide (CO2) in the blood, together with respiratory acidosis due to excessive retention of CO2.
The researchers say the technique should be undertaken in patients with deteriorating pulmonary oxygen transfer before hypoxemia is manifest, unless immediate endotracheal intubation is required for other reasons. Should pulmonary oxygen transfer not improve within the first hour of continuous nCPAP, they say further improvements are unlikely, and intubation and mechanical ventilation should not be delayed further.
On average, the study patients' age was approximately 60. There were 13 males and seven females involved in the clinical trial.
CHEST is published by the American College of Chest Physicians which represents 15,000 members who provide clinical, respiratory, and cardiothoracic patient care in the U.S. and throughout the world.
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Reporters may wish to contact Kimberly Lynch of the ACCP at (847) 498-8341 for a full copy of this article. She can also be reached by fax at (847) 498-5460 or by email at [email protected]. Detlef Kindgen-Milles can be reached by phone at 49-211-811-8101 or by email at [email protected].
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