Clinical Trial: Effects of Dobutamine on Microcirculation, Regional and Peripheral Perfusion in Septic Shock Patients

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effects of Dobutamine on Microcirculation, Regional and Peripheral Perfusion in Septic Shock Patients.

Brief Summary:

The investigators hypothesize that dobutamine is able to revert negative redistribution of flow by inducing a selective vasodilatory effect on hypoperfused territories, particularly at the sublingual and gastric mucosa, and at the peripheral tissues.

The investigators designed a randomized, cross-over, placebo-controlled study looking at the acute physiologic effects of 5 mcg/kg/min fixed-dose of dobutamine on cardiac function, microcirculation, gastric mucosal, hepatosplanchnic, and peripheral perfusion in septic shock patients.


Detailed Summary:

The investigators hypothesize that dobutamine is able to revert negative redistribution of flow by inducing a selective vasodilatory effect on hypoperfused territories, particularly at the sublingual and gastric mucosa, and at the peripheral tissues. Therefore, dobutamine improves microcirculatory alterations and regional perfusion in septic shock, independent of its effects on cardiac output.

The relevance of this concept is that it would support a more rational use of dobutamine in septic shock patients, not only as an inotrope to increase cardiac output, but more important, as a selective vasodilator aimed at restoring perfusion.

Therefore, the investigators designed a randomized, cross-over, placebo-controlled study looking at the acute physiologic effects of 5 mcg/kg/min fixed-dose of dobutamine on cardiac function, microcirculation, gastric mucosal, hepatosplanchnic, and peripheral perfusion in septic shock patients.


Sponsor: Pontificia Universidad Catolica de Chile

Current Primary Outcome: Change in the perfused vascular density [ Time Frame: 2.5 h ]

Perfused vessel density is a measure of sublingual microcirculation. It will be assessed with SDF videomicroscopy (Microscan ® for NTSC, Microvision Medical, Amsterdam, NL). (Crit Care 2007; 11:R101).


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Macrohemodynamics [ Time Frame: 2.5 h ]
    Macrohemodynamic values: mean arterial pressure, heart rate, and pulmonary artery catheter derived values (pulmonary artery occlusion pressure, cardiac index, systemic vascular resistance index)
  • Transthoracic echocardiography [ Time Frame: 2.5 h ]
    1. Morphology and diameters of cardiac cavities
    2. Left ventricular systolic function
    3. Right ventricular systolic function
    4. left ventricular diastolic function
  • Gastric mucosal perfusion [ Time Frame: 2.5 h ]
    Gastric mucosal perfusion: gastric air tonometry will be used to measure intraluminal pCO2 and calculate gastric - arterial pCO2 gradient (Tonocap, Datex)
  • Hepatosplanchnic blood flow [ Time Frame: 2.5 h ]
    This will be assessed by the ICG-PDR method. Each patient will receive an ICG finger clip which will be connected to a liver function monitor (LiMon Pulsion Medical Systems, Germany).
  • Peripheral perfusion [ Time Frame: 2.5 h ]
    1. Peripheral flow index (PFI), derived from the pulse oxymetry signal (MP20 IntelliVue monitor, Philips Medical systems, Amsterdam,NL)
    2. Temperatures at the blood (by PAC), and at different places in the skin. We will calculate central to toe gradient (Tc-toe), and forearm to fingertip skin temperature gradient (Tskin-diff)
    3. NIRS: Tissue oxygen saturation (StO2) will be measured by a tissue spectrometer (InSpectra Model 325, Hutchinson Technology, Hutchinson, Minn.)
  • Metabolic perfusion assessment [ Time Frame: 2.5 h ]
    We will measure mixed venous O2 saturation and arterial lactate


Original Secondary Outcome: Same as current

Information By: Pontificia Universidad Catolica de Chile

Dates:
Date Received: January 5, 2011
Date Started: August 2010
Date Completion:
Last Updated: June 25, 2015
Last Verified: June 2015