Linked Life Data

9493929

Source:http://linkedlifedata.com/resource/pubmed/id/9493929

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1998-5-4
pubmed:abstractText
Recording of respiratory airflow is an integral part of polysomnography (NPSG). It is conventionally monitored with a thermistor that measures temperature as a surrogate of flow. The subjectivity of interpreting hypopnea from this signal has prompted us to measure nasal airflow directly with a simple pneumotachograph consisting of a standard nasal cannula connected to a 2-cm H2O pressure transducer. We manually analyzed respiratory events using simultaneous thermistor and nasal cannula in 11 patients with obstructive sleep apnea syndrome (OSAS) and 9 with upper airway resistance syndrome (UARS). Definite events were scored separately for each signal when amplitude was <50% for >10 seconds. Events were also scored on the nasal cannula signal when the flattened shape of the signal suggested flow limitation, and these were tabulated separately. Definite events in one signal were tabulated by whether the other signal showed a definite event or not. In addition, nasal cannula events were compared to a more liberal thermistor criterion (any change in the signal for > or = 2 breaths). Visually, events were more easily recognized on the nasal cannula signal than on the thermistor signal. In OSAS, 1,873 definite thermistor events were detected. Of these, 99.1% were detected by nasal cannula, and 0.9% were missed. Of 3,541 definite nasal cannula events, 51.9% were detected by definite thermistor criteria; 75.0% were detected by liberal thermistor criteria; 25.0% were missed. In UARS, 123 definite thermistor events were detected. Of these, 89.4% were detected by nasal cannula and 10.6% were missed. Nine hundred and three nasal cannula events were detected. However, only 17.2% of these were detected by definite thermistor criteria; 38.6% were detected by liberal thermistor criteria; 61.4% were completely undetected by thermistor. When events identified on the nasal cannula by flow limitation alone were excluded, the thermistor detected 30.1% of events by definite criteria and 78.6% by liberal criteria, still leaving 21.4% completely undetected by the thermistor. We conclude that the nasal cannula reliably detects respiratory events seen by thermistor. Additional events (including some characterized only by flow limitation) that help define the UARS, were recognized by nasal cannula but often completely missed by thermistor. We propose that respiratory monitoring during NPSG with nasal cannula significantly improves event detection and classification over that with thermistor.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0161-8105
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1175-84
pubmed:dateRevised
2009-1-29
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Detection of respiratory events during NPSG: nasal cannula/pressure sensor versus thermistor.
pubmed:affiliation
Division of Pulmonary and Critical Care Medicine, New York University Medical Center, New York 10016, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't