The Greek e-journal of Perioperative Medicine

11-24

Authors: Zaralidou A, Maidatsi P, Gorgias N, Giala M

NSAIDs are widely used compounds in the management of several acute and chronic pain syndromes. NSAIDs induce their action by blocking the cyclooxygenase enzymes, cox-1 and cox-2, during the conversion of arachidonic acid to prostaglandins. Conventional NSAIDs inhibit both cox isoforms and are therefore at risk of serious complications as gastrointestinal irritation, postoperative bleeding, renal failure, water and sodium retention and hepatic failure. The newest cox-2 specific inhibitors are equally effective. Additionally they have superior safety and tolerability profile. The effects of cox-2 specific inhibitors have been assessed and have proved useful in the management of several acute and chronic pain syndromes such as osteoarthritis, rheumatoid arthritis, primary dysmenorrhea and low back pain. Also they have many advantages when used in a multimodal therapy during the perioperative period because they have opiod sparing action and provide adequate pain control without side effects. They are also used successfully in the management of cancer pain at all three steps on the analgesic ladder in combination with opioids and other adjuvant analgesics.

34-59

Authors: Petrou A, Chortaria G

Since the advent of clinical anesthesia, there has been a continuous need for evaluating the depth of anesthesia. Depth of anesthesia was always important in avoiding either overdose (toxicity) or “underdose” (administering less than absolutely necessary). The problem of overdosing has been partly solved by assignment of dedicated and specially trained doctors to provide anesthesia services, by accumulating more than a 100 years of experience in administering anesthesia, by using safer drugs (volatile and intravenous) with extremely smaller toxicity than the older ones and by recognizing and establishing the stages of anesthesia (such as Guedel stages) and the hemodynamic parameters as indirect but useful indices of the depth of anesthesia. The current trend of minimizing expenses of anesthesia calls for tight titration of drug administration. The problem of “underdosing” has evolved over the years either from surgeons being unhappy from the “operating conditions” (the patient presenting unnecessary and potentially harmful hemodynamic responses, moving or coughing as a response to surgical stimulus, with no muscle relaxation which diminishes the access to the abdominal cavity for example) or from patients who some times recall intraoperative events and even remember experiencing pain. This phenomenon, called awareness during anesthesia, has been acknowledged as a failure of providing anesthesia, even though the providers would assure that the patient was as calm as usual and the doses were within “usual range”. This complication signals psychological sequelae for the patient and legal problems for the anesthesiologist. Since the introduction of neurophysiologic monitoring and analysis to modern clinical practice, there has been a strenuous effort to invent indices that would predictably indicate the depth of anesthesia and point out those patients who are at increased risk of awareness during anesthesia. The Bispectral Index monitor, constructed by Aspect Medical Inc is based on EEG analysis and incorporates the empirical best clinical judgment that corresponds to certain EEG patterns. This index and many others attempt to enforce our clinical judgment with objective tools and hopefully provide better clinical outcome of either intravenous or inhalational anesthesia. This special article provides information on the EEG analysis that produces the BIS Index and reviews the clinical experience with it’s use. It concludes that BIS index is the best almost real time clinical tool on hand so far, for evaluating the depth of anesthesia, even though it’s specificity and sensitivity are not yet approaching the ideal monitors requirements.

68-76

Authors: Anagnostou T, Perraki M, Savvas I, Raptopoulos D

Pain has been defined by the International Association for the Study of Pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage”. However, the ability to describe the concept of pain is difficult largely because pain is an individualized and subjective experience. The mechanisms of nociception in animals have been found to resemble closely those present in humans. Although the exact nature of the experience of pain in animals may well differ from that experienced by humans, it is obviously an unpleasant sensation which all animals will try to avoid. Animals in pain show considerable alterations in physiological variables and also deviation from their normal behaviour. The problem of our inability to assess pain accurately in animals is almost certainly the major reason for our failure to control postoperative or other kinds of pain effectively. It has also been proved difficult to quantify pain in humans. Analgesia is not, however, refused to human patients purely because quantification is unreliable and subjective. Similarly, in animals the responsibility to relieve pain should not be avoided because pain cannot be accurately quantified. It is recommended that researchers should attempt to assess pain in experimental animals using an appropriate quantitative pain-scoring system, by selecting the variables used for scoring to suit the specific animal model concerned. The choice of variables should be made after observing a small number of animals in a pilot-study and determining which variables are most affected by the procedure. Relieving the pain inflicted on experimental animals by a research protocol is not just a moral obligation; it is also a scientific requirement, since pain may adversely affect research outcomes.

93-98

Authors: Filippopoulos K, Papagiannopoulou P, Foulidou A, Meitanidou M, Georgiadou Th, Sfyra E, Kanakoudis F

Atropine has been used in the past as a premedication drug to decrease the sialorrhea of the second stage of anaesthesia and prevent bradycardia caused by the administration of succinylcholine, opiods or volatile anaesthetics. The purpose of this study is the investigation of the haemodynamic fluctuations during induction of anaesthesia and intubation of the trachea, in children and adults either premedicated or not with atropine. After institutional approval 105 adults and 52 children ASA I-II were assigned in two groups (with or without atropine). Systolic Arterial Pressure (SAP) and Heart Rate (HR) were recorded in four phases: prior to induction before atropine administration, after the induction of anaesthesia, after the intubation of the trachea and five minutes later. Statistical difference in SAP fluctuatuion as well as in HR was found between groups (premedicated with atropine or not) in children. In adults no difference between groups was found. Conclusively, the administration of atropine does not influence the SAP and HR fluctuation in adult population during induction of anaesthesia and intubation of the trachea, but it seems to prevent or to moderate it in children.