OBJECTIVES: Our aim was to evaluate whether some biochemical parameters in the blood serum can establish and discriminate pain intensity of different etiology.
METHODS: Three groups of patients hospitalised at the Department of Surgery have been investigated: 1) the patients without pain but with the indicated surgical treatment, 2) the patients with acute pancreatitis, which represents severe pain of the visceral type, and 3) the patients with fractures of upper or lower extremities, which represented acute somatic pain. Whole serum proteins, albumin, C-reactive protein, glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglyceroles (triglycerides), apolipoprotein-B and electrophoretic levels of alpha-lipoprotein, beta-lipoprotein and pre-beta-lipoprotein were analysed immediately after the first clinical inspection in the hospital and then 30 days after treatment.
RESULTS: The intensity of pain estimated by the visual analogue scale (VAS) was higher in patients with acute pancreatitis than in patients with fractures. In both diagnoses during persisting pain, the products of lipid metabolism such as triacylglyceroles and HDL-cholesterol were enhanced together with glucose levels. Electrophoretic measurements, revealed higher levels of beta-lipoproteins in fractures, and increased values of pre-beta-lipoproteins and alpha-lipoproteins in both groups of patients suffering from pain. After 30 days of treatment some indicators decreased, but when compared with normal values, they were still higher, especially in patients with pancreatitis (HDL-cholesterol, triacylglyceroles, pre-beta-lipoprotein). In control patients without pain symptoms, an increase of LDL cholesterol, triacylglyceroles and beta-lipoprotein were observed during their stay in hospital, which may be considered to be due to hospitalisation stress per se. Acute stress generally influences glucose levels so that their increase cannot be considered as a specific marker of pain intensity.
CONCLUSIONS: It may be concluded from our investigation, that the biochemical composition of the blood serum is changing during painful states, although the question still remains open to what extent these changes reflect the pain intensity and to what extent they may modulate the perception of pain.