CONFLICT OF INTEREST: NONE DECLARED Evidence based medicine (EBM) is the conscientious, explicit, judicious and reasonable use of modern, best evidence in making decisions about the care of individual patients. EBM integrates clinical experience and patient values with the best available research information. It is a movement which aims to increase the use of high quality clinical research in clinical decision making. EBM requires new skills of the clinician, including efficient literature-searching, and the application of formal rules of evidence in evaluating the clinical literature. The practice of evidence-based medicine is a process of lifelong, self-directed, problem-based learning in which caring for one’s own patients creates the need for clinically important information about diagnosis, prognosis, therapy and other clinical and health care issues. It is not “cookbook” with recipes, but its good application brings cost-effective and better health care. The key difference between evidence-based medicine and traditional medicine is not that EBM considers the evidence while the latter does not. Both take evidence into account; however, EBM demands better evidence than has traditionally been used. One of the greatest achievements of evidence-based medicine has been the development of systematic reviews and meta-analyses, methods by which researchers identify multiple studies on a topic, separate the best ones and then critically analyze them to come up with a summary of the best available evidence. The EBM-oriented clinicians of tomorrow have three tasks: a) to use evidence summaries in clinical practice; b) to help develop and update selected systematic reviews or evidence-based guidelines in their area of expertise; and c) to enrol patients in studies of treatment, diagnosis and prognosis on which medical practice is based.

The study was designed to determine pre-, intra-and postoperative serum cortisol and prolactin (PRL) concentrations in patients subjected to low abdominal surgery under total intravenous anesthesia (TIVA) with propofol-fentanyl, and under general balanced anesthesia with isoflurane-fentanyl. The prospective study included 50 patients of both sexes, aged between 35 and 60 years, subjected to elective low abdominal surgery. Patients were randomly divided into two groups: an experimental group, consisting of 25 ASA I/II (American Society of Anesthesiologists I/II classification) patients treated under TIVA with propofol-fentanyl, and a control group consisting of 25 ASA I/II patients treated under balanced anesthesia with isoflurane-fentanyl. The length of the surgery and the degree of the surgical trauma did not differ significantly between the two anesthesia groups. Blood samples for cortisol and PRL measurements were drawn at exact time points: 30 minutes before the beginning of the surgery (T0), 30 minutes after the beginning of the surgery (T1), at the end of the surgery (T2), 2 hours after the surgery (T3), and 24 hours after the surgery (T4). Serum levels of cortisol and PRL were measured using commercially available kits. The results were evaluated with the nonparametric Mann-Whitney test. The serum concentration of cortisol measured at T1 time point in patients treated under TIVA was significantly lower (p=0.04) than that in patients treated under general balanced anesthesia. The average circulating levels of PRL measured at T1, T2 and T3 time points in patients treated under TIVA were significantly lower (p=0.003; p=0.002; p<0.05; respectively) than those in patients treated under balanced anesthesia. The results obtained suggest that the endocrine stress response developed in response to surgery is probably attenuated in patients treated under TIVA with propofol-fentanyl and, thus, that these patients are less stressed in comparison to patients treated under general balanced anesthesia with isoflurane-fentanyl.