Respiratory Variations in Pulse Pressure Reflect Central Hypovolemia during Noninvasive Positive Pressure Ventilation.
Background. Correct volume management is essential in patients with respiratory failure. We investigated the ability of respiratory variations in noninvasive pulse pressure (ΔPP), photoplethysmographic waveform amplitude (ΔPOP), and pleth variability index (PVI) to reflect hypovolemia during noninvasive positive pressure ventilation by inducing hypovolemia with progressive lower body negative pressure (LBNP). Methods. Fourteen volunteers underwent LBNP of 0, -20, -40, -60, and -80 mmHg for 4.5 min at each level or until presyncope. The procedure was repeated with noninvasive positive pressure ventilation. We measured stroke volume (suprasternal Doppler), ΔPP (Finapres), ΔPOP, and PVI and assessed their association with LBNP-level using linear mixed model regression analyses. Results. Stroke volume decreased with each pressure level (-11.2 mL, 95% CI -11.8, -9.6, P < 0.001), with an additional effect of noninvasive positive pressure ventilation (-3.0 mL, 95% CI -8.5, -1.3, P = 0.009). ΔPP increased for each LBNP-level (1.2%, 95% CI 0.5, 1.8, P < 0.001) and almost doubled during noninvasive positive pressure ventilation (additional increase 1.0%, 95% CI 0.1, 1.9, P = 0.003). Neither ΔPOP nor PVI was significantly associated with LBNP-level. Conclusions. During noninvasive positive pressure ventilation, preload changes were reflected by ΔPP but not by ΔPOP or PVI. This implies that ΔPP may be used to assess volume status during noninvasive positive pressure ventilation.
Norwegian Air Ambulance Foundation, Holterveien 24, 1441 Drøbak, Norway ; Department of Anaesthesiology, Oslo University Hospital, P.O. Box 4956, Nydalen, 0424 Oslo, Norway.
Ingrid Elise
0000-0001-7001-9530
IE
Hoff
Department of Anaesthesiology, Oslo University Hospital, P.O. Box 4956, Nydalen, 0424 Oslo, Norway ; Faculty of Medicine, University of Oslo, P.O. Box 1072 Blindern, 0316 Oslo, Norway.
Lars Øivind
LØ
Høiseth
Department of Vascular Medicine, Oslo University Hospital, P.O. Box 4956, Nydalen, 0424 Oslo, Norway.
Jonny
J
Hisdal
Norwegian Air Ambulance Foundation, Holterveien 24, 1441 Drøbak, Norway ; Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, P.O. Box 1072 Blindern, 0316 Oslo, Norway.
Jo
J
Røislien
Department of Anaesthesiology, Oslo University Hospital, P.O. Box 4956, Nydalen, 0424 Oslo, Norway.
Svein Aslak
SA
Landsverk
Department of Anaesthesiology, Oslo University Hospital, P.O. Box 4956, Nydalen, 0424 Oslo, Norway ; Faculty of Medicine, University of Oslo, P.O. Box 1072 Blindern, 0316 Oslo, Norway.
Knut Arvid
0000-0002-3213-6821
KA
Kirkebøen