[Free fatty acids as an indicator of preoperative stress and effects of premedication with flunitrazepam, morphine and promethazine on blood fatty acid level].

We investigated the influence of different oral premedication given to 50 male and 50 female patients on the plasmaconcentration of free fatty acids (FFA) as an indicator of preoperative stress and compared them with patients given no premedication at all. FFA are measured with a gaschromatographic method. FFA were measured four times: Time 1 (t1): the first day in hospital, t2: After the anesthesiologist's visit, t3: In the morning of the operation, t4: Before starting anesthesia. The groups are: I. 20 male and 20 female patients without any premedication; II. every 10 patients of both sexes given 2 mg Flunitrazepam (p.o.) on the preoperative night; III. every 10 patients given Morphium (0.15 mg i.m.) and Promethazin (50 mg i.m.) and, last, IV. every 10 patients getting the same premedication as group II and IV. 98 patients had a significant decrease of FFA from t1 to t2. The FFA of all increased from t2 to t3. Moreover, there was an increase from t3 to t4. We conclude from this that no premedication we had investigated is able to lower the physiological and biochemical stress-response as far as shown by FFA. Apart from myristic-acid, there was no difference in the groups. However, with no statistic significance, both 'Flunitrazepam-groups' showed the lowest increase. Further, in 28 from 32 cases, females had a higher FFA-level than males (in 16 cases with statistical significance).