Figure 1.
Baseline and steady state measurements included duplicate blood samples for metabolic measurements in all piglets and video microscopic examination of the cortical microvascular heterogeneity in of the 12 piglets. Blood pressure fluctuations were induced pharmacologically and nonpharmacologically to evaluate a possible direct drug induced effect on cerebral perfusion and oxygenation. PR, pulse rate; MAP, mean arterial blood pressure; SaO2, arterial oxygen saturation; LDF, laser Doppler flow; OI, oxygenation index; NIRS, near infrared spectroscopy.
Figure 2.
Short infusions of the vasopressors.
Example of pharmacologically (first 10 min) and nonpharmacologically (last 10 min) induced changes in mean arterial blood pressure (MAP) and corresponding changes in cerebral perfusion (LDF in % from baseline) and oxygenation (OI measured with near infrared spectroscopy). Pharmacologically induced changes consisted of two repeated infusions lasting 2½ minute, interspaced with pauses lasting 2½ minute to reach baseline levels. This was followed by nonpharmacological MAP fluctuations induced by balloon inflations: the thoracic aorta balloon was inflated 10 times, and inflations lasted 30 sec interspaced by 30 sec pauses. The vertical line represents a 10 min pause between the induced changes in MAP.
Table 1.
Steady state responses during vasopressor infusion.
Table 2.
Comparison of the effects of adrenaline, dopamine and noradrenaline on cerebral perfusion and oxygenation.
Table 3.
Cerebral responses during short repeated infusions.