[Role of prostaglandins in the regulation of intrapulmonary shunting during lung surgery].

Pulmonary and systemic hemodynamics, gas exchange, intrapulmonary shunting (IS), arterial and mixed venous blood levels of prostaglandin-like substances (PGE + A and PGF2a) have been studied in 63 patients during lung surgery under multicomponent anesthesia with halothane and fentanyl. It has been established that 17% of patients developed intraoperatively arterial hypoxemia associated with IS increase. IS changes resulted from local active release of prostaglandins, mostly E + A group ones, possessing a vasodilating effect in pulmonary vessels.

[Endogenous humoral regulators directly before an operation].

It has been shown that modern premedication techniques do not prevent the activation of the sympathoadrenal system and the enhanced synthesis of cyclic nucleotides and prostaglandin-like compounds in response to preoperative stress. In a great number of patients there are no hemodynamic shifts in the nearest preoperative period, as an increased production of prostaglandins E and cyclic nucleotides (cAMP), that is of compensatory value, is observed. When normal relations between endogenous vasoactive substances with constricting and dilating effects are damaged, a hyperdynamic reaction ensures.