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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 1
pubmed:dateCreated
2000-4-25
pubmed:abstractText
Variation in respiratory impedance may occur in mechanically ventilated patients. During pressure-targeted ventilatory support, this may lead to patient-ventilator asynchrony. We assessed the hypothesis that during pressure-support ventilation (PSV), preservation of minute ventilation (V E) consequent to added mechanical loads would result in an increase in respiratory rate (RR) due to the large reduction in tidal volume (VT). WITH proportional-assist ventilation (PAV), preservation of V E would occur through the preservation of VT, with a smaller effect on RR. We anticipated that this compensatory strategy would result in greater patient comfort and a reduce work of breathing. An increase in respiratory impedance was obtained by chest and abdominal binding in 10 patients during weaning from mechanical ventilation. V E remained constant in both ventilatory modes after chest and abdominal compression. During PSV, this maintenance of VE was obtained through a 58 +/- 3% increase in RR that compensated for a 29 +/- 2% reduction in VT. The magnitudes of the reduction in VT (10 +/- 3%) and of the increase in RR (14 +/- 2%) were smaller (p < 0. 001) during PAV. During both PSV and PAV, chest and abdominal compression caused increases in both the pressure-time product (PTP) of the diaphragm per minute (142.9 +/- 26.9 cm H(2)O. s/min, PSV, and 117.6 +/- 16.4 cm H(2)O. s/min, PAV) and per liter (13.4 +/- 2.5 cm H(2)O. s/L, PSV, and 9.6 +/- 0.7 cm H(2)O. s/L, PAV). These increments were greater (p < 0.001) during PSV than during PAV. The capability of keeping VT and V E constant through increases in inspiratory effort after increases in mechanical loads is relatively preserved only during PAV. The ventilatory response to an added respiratory load during PSV required greater muscle effort than during PAV.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1073-449X
pubmed:author
pubmed:issnType
Print
pubmed:volume
161
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
819-26
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Compensation for increase in respiratory workload during mechanical ventilation. Pressure-support versus proportional-assist ventilation.
pubmed:affiliation
Dipartimento di Emergenza e Trapianti d'Organo, sezione di Anestesiologia Rianimazione, Ospedale Policlinico, Università di Bari, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't