Effects of different mean arterial pressure levels on hemodynamics, tissue perfusion and oxygen metabolism in elderly patients with septic shock / 中华老年医学杂志

ABSTRACT

ObjectiveTo observe the effects of norepinephrine and dobutamine (NE+Dobu) on hemodynamics, tissue perfusion and oxygen metabolism in elderly patients with septic shock at different levels of mean arterial pressure (MAP). MethodsAfter aggressive fluid resuscitation,norepinephrine and dobutamine were administered in 18 elderly patients with septic shock to correct hypotension. The rate of dobutamine infusion was 5 ug. kg<'-1>. min<'-1> Norepinephrine was titrated to maintain MAP at levels of 65 mm Hg, 75 mm Hg and 85 mmHg. Four hours later, the changes of hemodynamics, oxygenation index, blood lactate, renal function and gastric pCO<,2> at every MAP level were observed. ResultsThere were no significant differences in heart rate (HR), pulmonary arterial wedge pressure (PAWP), volume of oxygen (VO<,2>), Blood lactate, pH value, △pCO<'2> and creatinine clearance rate (CCr) among the MAP levels of 65 mm Hg, 75 mm Hg and 85 mm Hg ( all P>0.05). Compared with MAP 65 mm Hg, cardiac index (CI), systemic vascular resistance index (SVRI), oxygen delivery over oxygen extraction ratio were obviously higher at MAP 75 mm Hg and 85 mm Hg [4.7±0.6, 5.1±0.7 vs. 4.0±0.6; 1162±278, 1276±319 vs. 1011±225; (697±53) ml. min<'1>. m<'2>,(711±68)ml. min<'-1>. m<'2> vs. (634±70) ml · min<'-1> · m<'2>; (0.28±0.02)%,(0.27±0.02)% vs. (0.25±0.02) %, respectively, all P<0.05). The urinary output at MAP levels of 65 mm Hg, 75 mm Hg and 85 mm Hg were (98±43)ml/h, (91±54) ml/h and(74±49)ml/h repectively, and only the differences between MAP 75 mm Hg and MAP 65 mm Hg had statistical significance (P<0.05).ConclusionsAfter aggressive fluid resuscitation, hemodynamics and renal function are improved at MAP 75 mm Hg after administration of norepinephrine and dobutamine in elderly patients with septic shock. It should be considered that MAP is appropriately increased in elderly patients with septic shock.