Breathing pattern and perception at different levels of volume assist and pressure support in volunteers.
Objective: Volume assist (VA) amplifies the breathing effort whereas pressure support ventilation (PSV) provides a fixed, effort-independent ventilatory support. According to the concept of VA, its level should compensate for the pathologically increased (additional) elastance (Eadd). However, it is...
| Published in: | Critical Care Medicine Vol. 29; no. 5; pp. 982 - 989 |
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| Main Authors: | , , , , , , , , , |
| Format: | research tables/charts Journal Article |
| Published: |
Lippincott Williams & Wilkins
2001 May
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| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=107042470&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 107042470 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00903493 04O jtl: Critical Care Medicine issn: 00903493 maglogo: N pubinfo: dt: 2001 May vid: 29 iid: 5 pid: 433 pub: Lippincott Williams & Wilkins place: Baltimore, Maryland artinfo: ui: 107042470 107042470 NLM11378608 2001071321 NLM11378608 107042470 ppf: 982 ppct: 7 formats: tig: atl: Breathing pattern and perception at different levels of volume assist and pressure support in volunteers. aug: au: Mols G Vetter T Haberthür C Geiger K Guttmann J Mols, G Vetter, T Haberthür, C Geiger, K Guttmann, J affil: Department of Anesthesiology and Critical Care Medicine, University of Freiburg, Freiburg, Germany sug: subj: Positive Pressure Ventilation Respiration, Artificial Methods Respiration Respiratory Distress Syndrome, Acute Therapy Lung Compliance Prospective Studies Regression Wilcoxon Signed Rank Test Analysis of Variance Repeated Measures Two-Way Analysis of Variance Adult Female Male Funding Source Human Adult: 19-44 years Female Male ab: Objective: Volume assist (VA) amplifies the breathing effort whereas pressure support ventilation (PSV) provides a fixed, effort-independent ventilatory support. According to the concept of VA, its level should compensate for the pathologically increased (additional) elastance (Eadd). However, it is unclear whether breathing subjects prefer an exact compensation of Eadd and whether they are able to adjust the support level by themselves.Design: Prospective, interventional study.Setting: Laboratory.Subjects: Twelve healthy volunteers, nine females, three males, aged 21-33 yrs.Interventions: Increased Eadd was generated by banding of the thorax and abdomen. Volunteers breathed via a mouthpiece with VA or PSV using a positive end-expiratory pressure of 5 cm H2O (0.5 kPa). The study was subdivided into two parts. In part I, volunteers were instructed to adjust the level of VA and PSV themselves starting from three different, randomly applied levels in each mode (2, 8, 14 cm H2O or cm H2O/L; 0.2, 0.8, 1.4 kPa[/L]). In part II, 20 levels of VA and PSV (1-20 cm H2O or cm H2O/L, 0.1-2 kPa[/L]) were randomly selected by an investigator and estimated by the volunteers using a visual analog scale. Additionally, the breathing pattern was characterized.Measurements and Main Results: Eadd (7.1 +/- 1.5 cm H2O/L [0.7 +/- 0.2 kPa/L], mean +/- sd) corresponded almost exactly to the "self-adjusted" VA level of part I (7.0 +/- 3.3 cm H2O/L [0.7 +/- 0.3 kPa/L]) and to the adequate level of part II (8-9 cm H2O/L [0.8-0.9 kPa/L]). The accordant PSV levels were 5.7 +/- 2.6 cm H2O (0.6 +/- 0.3 kPa) and 6-7 cm H2O (0.6-0.7 kPa). The breathing pattern was less influenced by changes of the support level with VA compared with PSV, which may explain in part the greater comfort of VA.Conclusions: We confirmed the theoretical assumption that VA should be adapted to Eadd. Furthermore, we demonstrated that conscious subjects are able to adjust the level of VA and PSV themselves. pubtype: Academic Journal doctype: research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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