Cardiovascular aspects of experimental meningococcal sepsis in young and older awake piglets: Age-related differences

Severe meningococcal disease is characterized by: a high load of specific e ndotoxin, capillary leakage and coagulation disorders. We studied the possi ble age-related differences in global hemodynamic and regional blood flow r esponses to different dosages (1 and 10 mu g/kg body weight) of rough menin gococcal endotoxin in young (8 kg) and older piglets (40 kg). Animals were chronically instrumented and studied in the awake state. The response to pl asma infusion (30 mL/kg in 30 min) was evaluated after placebo and endotoxi n infusion. The clinical picture was similar in all groups. The mortality w as 0/8, 3/8, 1/8, 4/9 in young-low, young-high, old-low, and old-high dose respectively. Most important findings were that cardiac index (CI) decrease d in the young animals after endotoxin infusion, while it was well preserve d in the older animals; in the older animals the systemic vascular resistan ce dropped 20%, while in the younger ones there was no change in resistance . Conductance to the kidneys, intestines, and spleen decreased significantl y more in the young animals, while the increase in conductance and flow to the liver was higher in the old animals; subsequent volume loading resulted only partly in a recovery of the hemodynamic parameters, but failed to imp rove oxygen delivery.