[Clinical implication of blood somatostatin determination in critically ill patients]

To investigate the relationship between contents of blood somatostatin (SST) and inflammatory reaction or severity of illness in critically ill patients, and its value in the evaluation of prognosis.

Sixty critically ill patients were divided into three groups according to the acute physiology and chronic health evaluation II (APACHE II) score as mild (<16, 23 cases), mediate (16 - 20, 20 cases) and severe (>20, 17 cases) group; and also divided as dead (D, 13 cases) or survival group (S, 47 cases) according to the final outcome; 20 healthy volunteers served as control. The blood SST concentration was detected by radioimmunoassay, while the levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were measured by enzyme linked immunosorbent assay (ELISA).

The SST concentration in critically ill patients was significantly lower than normal control [(18.2+/-17.6) ng/L vs. (224.8+/-130.2) ng/L, P<0.05], while the levels of TNF-alpha and IL-6 were significantly higher [TNF-alpha: (32.4+/-14.2) ng/L vs. (14.2+/-5.7) ng/L, IL-6: (131.6+/- 42.7) ng/L vs. (65.8+/-24.3) ng/L, both P<0.05]. The SST concentration in severe group was significantly lower than that of mild and mediate group [(8.1+/-7.2) ng/L vs. (24.7+/-15.9) ng/L and (19.2+/-22.1) ng/L, both P<0.05], while the levels of TNF-alpha and IL-6 were significantly higher than mild group [TNF-alpha: (39.0+/-16.4) ng/L vs. (28.9+/-10.9) ng/L, IL-6: (156.0+/-49.6) ng/L vs. (111.5+/-32.6) ng/L, both P<0.05]. A negative correlation was found between SST and TNF-alpha, IL-6, also between SST and APACHE II score (r(1)=-0.682, r(2)=-0.894, r(3)=-0.327, P<0.05 or P<0.01). The SST concentration in D group was significantly lower than S group [(6.4+/-5.5) ng/L vs. (21.5+/-18.4) ng/L, P<0.05].

The SST level in blood can reflect the severity of illness in critically ill patients and shows clinical value in evaluation of prognosis.