British Journal of Anaesthesia, Vol 81, Issue 6 920-924, Copyright © 1998 by The Board of Management and Trustees of the British Journal of Anaesthesia
R. Kato, J. Sato and T. Nishino
We have studied the effect of milrinone on pulmonary vascular resistance
(PVR) in dogs with hypoxic pulmonary vasoconstriction (HPV). Using a
pulmonary arterial occlusion method, we measured effective pulmonary
capillary pressure (Pcap) by which total PVR was partitioned into arterial
(PVRa) and venous (PVRv) components. Hypoxic ventilation (FIO2 = 0.11-0.13)
produced significant increases in mean pulmonary arterial pressure (PAP)
and Pcap (P < 0.01) associated with increases in PVRa and PVRv (P <
0.01). During the hypoxic period, milrinone significantly decreased mean
PAP and Pcap (P < 0.01), reflected in decreases in PVRa and PVRv (P <
0.01). The longitudinal distribution of PVR (PVRa/PVRv) remained unchanged
throughout the experiment, indicating that HPV occurred equally in the
arterial and venous segments and that milrinone-induced vasodilatation
occurred equally in both segments. During hypoxia, milrinone did not
produce an increase in cardiac output or a decrease in PaO2. Milrinone also
produced significant decreases in mean systemic arterial pressure (P <
0.01) and systemic vascular resistance (P < 0.05) to a similar extent to
the decreases in mean PAP and PVR, suggesting no selective dilating effect
of milrinone on the pulmonary vasculature. These results indicate that in
HPV, milrinone decreased the vascular tone of both pulmonary arterial and
venous segments without increasing cardiac work or impairing pulmonary
oxygenation. This suggests a potential for use in patients suffering from
hypoxic pulmonary hypertension.
LABORATORY INVESTIGATIONS
Milrinone decreases both pulmonary arterial and venous resistances in the hypoxic dog
Department of Anaesthesiology, School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan
![]()
CiteULike
Connotea
Del.icio.us What's this?