Can a central blood volume deficit be detected by systolic pressure variation during spontaneous breathing?. Issue 1 (December 2015)

• Record Type: Journal Article
• Authors: Dahl, Michael; Hayes, Chris; Steen Rasmussen, Bodil; Larsson, Anders; Secher, Niels
• Is Part Of: BMC anesthesiology. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 8
• Publication Date: 2015-12
• Subjects: Fluid responsiveness -- Spontaneous breathing -- Head-up tilt -- Pulse pressure variation -- Stroke volume variation -- Systolic pressure variation; Anesthetics -- Periodicals; Anesthesia -- Periodicals; Anesthesiology -- Periodicals; 617.9605
• DOI: 10.1186/s12871-016-0224-z
• Languages: English
• ISSNs: 1471-2253

Abstract

Abstract Background Whether during spontaneous breathing arterial pressure variations (APV) can detect a volume deficit is not established. We hypothesized that amplification of intra-thoracic pressure oscillations by breathing through resistors would enhance APV to allow identification of a reduced cardiac output (CO). This study tested that hypothesis in healthy volunteers exposed to central hypovolemia by head-up tilt. Methods Thirteen healthy volunteers were exposed to central hypovolemia by 45° head-up tilt while breathing through a facemask with 7.5 cmH2 O inspiratory and/or expiratory resistors. A brachial arterial catheter was used to measure blood pressure and thus systolic pressure variation (SPV), pulse pressure variation and stroke volume variation . Pulse contour analysis determined stroke volume (SV) and CO and we evaluated whether APV could detect a 10 % decrease in CO. Results During head-up tilt SV decreased form 91 (±46) to 55 (±24) mL (mean ± SD) and CO from 5.8 (±2.9) to 4.0 (±1.8) L/min (p < 0.05), while heart rate increased (65 (±11) to 75 (±13) bpm;P < 0.05). Systolic pressure decreased from 127 (±14) to 121 (±13) mmHg during head-up tilt, while SPV tended to increase (from 21 (±15)% to 30 (±13)%). Yet during head-up tilt, a SPV ≥ 37 % predicted a decrease in CO ≥ 10 % with a sensitivity and specificity of 78 % and 100 %, respectively. Conclusion In spontaneously breathing healthy volunteers combined inspiratory and expiratory resistors enhance SPV during head-up tilted induced central hypovolemia and allow identifying a 10 % reduction in CO. Applying inspiratory and expiratory resistors might detect a fluid deficit in spontaneously breathing patients. Trial registration ClinicalTrials.gov numberNCT02549482 Registered September 10th 2015.