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Pulse Pressure Respiratory Variation as an Early Marker of Cardiac Output Fall in Experimental Hemorrhagic Shock
Author(s) -
Westphal Glauco,
Garrido Alejandra del Pilar Gallardo,
De Almeida Daniela Paoli,
Rocha e Silva Maurício,
PolideFigueiredo Luiz Francisco
Publication year - 2007
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.2007.00377.x
Subject(s) - blood volume , cardiac output , central venous pressure , shock (circulatory) , blood pressure , anesthesia , stroke volume , pulse pressure , medicine , mean arterial pressure , hemodynamics , pulmonary wedge pressure , cardiology , heart rate
Pulse pressure (ΔPp) and systolic pressure (ΔPs) variations have been recommended as predictors of fluid responsiveness in critically ill patients. We hypothesized that changes in ΔPp and ΔPs parallel alterations in stroke volume (SV) and cardiac output (CO) during hemorrhage, shock, and resuscitation. In anesthetized and mechanically ventilated mongrel dogs, a graded hemorrhage (20 mL/min) was induced to a target mean arterial pressure (MAP) of 40 mm Hg, which was maintained for additional 30 min. Total shed‐blood volume was then retransfused at a 40 mL/min rate. CO, SV, right atrial pressure (RAP), pulmonary artery occlusion pressure (PAOP), and continuous mixed venous oxygen saturation (SvO 2 ) were assessed. Both ΔPp and ΔPs were calculated from direct arterial pressure waveform. Removal of about 9% of estimated blood volume promoted a reduction in SV (14.8 ± 2.2 to 10.6 ± 1.3 mL, P < 0.05). At ∼18% blood volume removal, significant changes in CO (2.4 ± 0.2 to 1.5 ± 0.2 mL/min, P < 0.05), ΔPp (12.6 ± 1.4 to 15.8 ± 2.0%, P < 0.05), and SvO 2 (82 ± 1.4 to 73 ± 1.7%, P < 0.05) were observed. Alterations in MAP, RAP, PAOP, and ΔPs could be detected only after each animal had lost over 36% of estimated initial blood volume. There was correlation between blood volume loss and SV, CO, and SvO 2 , as well as between blood loss and MAP, ΔPp, and ΔPs. Blood volume loss showed no correlation with cardiac filling pressures. ΔPp is a useful, early marker of SV and CO for the assessment of cardiac preload changes in hemorrhagic shock, while cardiac filling pressures are not.