Ülkü Aypar

Spinal 5-HT7 receptors play an important role in the antinociceptive and antihyperalgesic effects of tramadol and its metabolite, O-Desmethyltramadol, via activation of descending serotonergic pathways.

Background:Tramadol is an analgesic drug, and its mechanism of action is believed to be mediated by the &mgr;-opioid receptor. A further action of tramadol has been identified as blocking the reuptake of serotonin (5-HT). One of the most recently identified subtypes of 5-HT receptor is the 5-HT7 receptor. Thus, the authors aimed to examine the potential role of serotonergic descending bulbospinal pathways and spinal 5-HT7 receptors compared with that of the 5-HT2A and 5-HT3 receptors in the antinociceptive and antihyperalgesic effects of tramadol and its major active metabolite O-desmethyltramadol (M1) on phasic and postoperative pain models. Methods:Nociception was assessed by the radiant heat tail-flick and plantar incision test in male Balb-C mice (25-30 g). The serotonergic pathways were lesioned with an intrathecal injection of 5,7-dihydroxytryptamine. The selective 5-HT7, 5-HT2, and 5-HT3 antagonists; SB-269970 and SB-258719; ketanserin and ondansetron were given intrathecally. Results:Systemically administered tramadol and M1 produced antinociceptive and antihyperalgesic effects. The antinociceptive effects of both tramadol and M1 were significantly diminished in 5-HT-lesioned mice. Intrathecal injection of SB-269970 (10 &mgr;g) and SB-258719 (20 &mgr;g) blocked both tramadol- and M1-induced antinociceptive and antihyperalgesic effects. Ketanserin (20 &mgr;g) and ondansetron (20 &mgr;g) were unable to reverse the antinociceptive and antihyperalgesic effects of tramadol and M1. Conclusions:These findings suggest that the descending serotonergic pathways and spinal 5-HT7 receptors play a crucial role in the antinociceptive and antihyperalgesic effects of tramadol and M1.

Ketamine gargle for attenuating postoperative sore throat

BACKGROUND Tracheal intubation is a foremost cause of trauma to the airway mucosa, resulting in postoperative sore throat (POST) with reported incidences of 21-65%. We compared the effectiveness of ketamine gargles with placebo in preventing POST after endotracheal intubation. METHODS Forty-six, ASA I-II, patients undergoing elective surgery for septorhinoplasty under general anaesthesia were enrolled in this prospective, randomized, placebo-controlled, single-blind study. Patients were randomly allocated into two groups of 23 subjects each: Group C, saline 30 ml; Group K, ketamine 40 mg in saline 30 ml. Patients were asked to gargle this mixture for 30 s, 5 min before induction of anaesthesia. POST was graded at 0, 2, 4, and 24 h after operation on a four-point scale (0-3). RESULTS POST occurred more frequently in Group C, when compared with Group K, at 0, 2, and 24 h and significantly more patients suffered severe POST in Group C at 4 and 24 h compared with Group K (P<0.05). CONCLUSIONS Ketamine gargle significantly reduced the incidence and severity of POST.

International study on microcirculatory shock occurrence in acutely ill patients

Objectives:Microcirculatory alterations are associated with adverse outcome in subsets of critically ill patients. The prevalence and significance of microcirculatory alterations in the general ICU population are unknown. We studied the prevalence of microcirculatory alterations in a heterogeneous ICU population and its predictive value in an integrative model of macro- and microcirculatory variables. Design:Multicenter observational point prevalence study. Setting:The Microcirculatory Shock Occurrence in Acutely ill Patients study was conducted in 36 ICUs worldwide. Patients:A heterogeneous ICU population consisting of 501 patients. Interventions:None. Measurements and Main Results:Demographic, hemodynamic, and laboratory data were collected in all ICU patients who were 18 years old or older. Sublingual Sidestream Dark Field imaging was performed to determine the prevalence of an abnormal capillary microvascular flow index (< 2.6) and its additional value in predicting hospital mortality. In 501 patients with a median Acute Physiology and Chronic Health Evaluation II score of 15 (10–21), a Sequential Organ Failure Assessment score of 5 (2–8), and a hospital mortality of 28.4%, 17% exhibited an abnormal capillary microvascular flow index. Tachycardia (heart rate > 90 beats/min) (odds ratio, 2.71; 95% CI, 1.67–4.39; p < 0.001), mean arterial pressure (odds ratio, 0.979; 95% CI, 0.963–0.996; p = 0.013), vasopressor use (odds ratio, 1.84; 95% CI, 1.11–3.07; p = 0.019), and lactate level more than 1.5 mEq/L (odds ratio, 2.15; 95% CI, 1.28–3.62; p = 0.004) were independent risk factors for hospital mortality, but not abnormal microvascular flow index. In reference to microvascular flow index, a significant interaction was observed with tachycardia. In patients with tachycardia, the presence of an abnormal microvascular flow index was an independent, additive predictor for in-hospital mortality (odds ratio, 3.24; 95% CI, 1.30–8.06; p = 0.011). This was not true for nontachycardic patients nor for the total group of patients. Conclusions:In a heterogeneous ICU population, an abnormal microvascular flow index was present in 17% of patients. This was not associated with mortality. However, in patients with tachycardia, an abnormal microvascular flow index was independently associated with an increased risk of hospital death.

Dexmedetomidine and postoperative shivering in patients undergoing elective abdominal hysterectomy.

Background Post‐anaesthetic shivering is one of the most common complications, occurring in 5–65% of patients recovering from general anaesthesia and 33% of patients receiving epidural anaesthesia. Our objective was to investigate the efficacy of intraoperative dexmedetomidine infusion on postoperative shivering. Methods Ninety female patients, ASA I‐II, 35–60 yr old, scheduled for elective total abdominal hysterectomy with or without bilateral salpingo‐oophorectomy were randomized into two groups. After endotracheal intubation one group received normal saline infusion and the other received dexmedetomidine as a loading dose of 1 &mgr;g kg−1 for 10 min followed by a maintenance infusion of 0.4 &mgr;g kg−1 h−1. In the recovery room, pain was assessed using a 100 mm visual analogue scale and those patients who had a pain score of more than 40 mm were administered 1 mg kg−1 intramuscular diclofenac sodium. Patients with shivering grades more than 2 were administered 25 mg intravenous meperidine. Patients were protected with passive insulation covers. Results Post‐anaesthetic shivering was observed in 21 patients in the saline group and in seven patients in the dexmedetomidine group (P = 0.001). Shivering occurred more often in the saline group. The Ramsay Sedation Scores were higher in the dexmedetomidine group during the first postoperative hour. Pain scores were higher in the saline group for 30 min after the operation. The need for intraoperative atropine was higher in the dexmedetomidine group. Intraoperative fentanyl use was higher in the saline group. Perioperative tympanic temperatures were not different between the groups whereas postoperative measurements were lower in the dexmedetomidine group (P < 0.05). Conclusion Intraoperative dexmedetomidine infusion may be effective in the prevention of post‐anaesthetic shivering.

The efficacy of intravenous or peritonsillar infiltration of ketamine for postoperative pain relief in children following adenotonsillectomy.

Background : A few previous studies have suggested the efficacy of i.v. ketamine for postoperative pain relief in children after adenotonsillectomy, but none has investigated the efficacy of peritonsillar infiltration of ketamine in these children.

Perioperative effects of melatonin and midazolam premedication on sedation, orientation, anxiety scores and psychomotor performance.

Background and objective: To compare the perioperative effects of melatonin and midazolam given in premedication, on sedation, orientation, anxiety scores and psychomotor performance. Methods: Exogenous administration of melatonin not only facilitates the onset of sleep but also improves its quality. A prospective, randomized, double-blind, placebo-controlled study was performed in 66 patients undergoing laparoscopic cholecystectomy. Patients were given melatonin 5 mg, midazolam 15 mg or placebo, 90 min before anaesthesia, sublingually. Sedation, orientation and anxiety were quantified before; 10, 30, 60 and 90 min after premedication; and 15, 30, 60 and 90 min after admission to the recovery room. Neurocognitive performance was evaluated at these times, using the Trail Making A and B and Word Fluency tests. The differences between the groups were analysed by ANOVA. Two-way comparisons were performed by Scheffé analysis. Sedation and amnesia were analysed by the χ2 test. Results: Patients who received premedication with either melatonin or midazolam had a significant increase in sedation and decrease in anxiety before operation compared with controls. After operation, there was no difference in sedation scores of all groups. Whereas, 30, 60 and 90 min after premedication the melatonin and midazolam groups exhibited a significantly poorer performance in Trail Making A and B tests compared with placebo, there were no significant differences among the groups in terms of neuropsychological performance after the operation. Amnesia was notable only in the midazolam group for one preoperative event. Conclusion: Melatonin premedication was associated with preoperative anxiolysis and sedation without postoperative impairment of psychomotor performance.

Comparison of propofol‐fentanyl with propofol‐fentanyl‐ketamine combination in pediatric patients undergoing interventional radiology procedures

Background:  With an increase in the frequency of interventional radiology procedures in pediatrics, there has been a corresponding increase in demand for procedural sedation to facilitate them. The purpose of our study was to compare the frequency of adverse effects, sedation level, patient recovery characteristics in pediatric patients receiving intravenous propofol fentanyl combination with or without ketamine for interventional radiology procedures. Our main hypothesis was that the addition of ketamine would decrease propofol/fentanyl associated desaturation.

Propofol offers no advantage over isoflurane anesthesia for cerebral protection during cardiopulmonary bypass: a preliminary study of S-100beta protein levels.

PurposeDespite advances in anesthesia, cardiopulmonary bypass (CPB) and surgical techniques, cerebral injury remains a major source of morbidity after cardiac surgery. We compared the effects of two different anesthetic techniques, isoflurane vs propofol on neurological outcome by serum S-100ß protein and neuropsychological tests after coronary artery bypass grafting (CABG).MethodsTwenty patients undergoing CABG, randomly allocated into two groups, were enrolled in this prospective, controlled, preliminary study. Isoflurane was used in group I and propofol in group R Neurological examination and a neuropsychologic test battery consisting of the mini mental state examination (MMSET) and the visual aural digit span test (VADST) were obtained preoperatively and on the third and sixth postoperative days. Blood samples for analysis of S-100ß protein were collected before anesthesia (T1), after heparinization (T2), 15 min into CPB (T3), after CPB (T4) and at the 24th hr postoperatively (T5).ResultsPostoperative neurological examinations of the patients were normal. VADST performance declined significantly on the third day (P < 0.05) in both groups, and there were no significant differences on VADST and MMSET scores between the two groups. In group P S-100ß protein levels increased significantly at T3 and T4 compared to preoperative and isoflurane levels (P < 0.05).ConclusionsDespite reports about the neuroprotective effects of propofol, S-100ß protein levels were significantly elevated in group R Although there was no deterioration in neuropsychological outcome, propofol appeared to offer no advantage over isoflurane for cerebral protection during CPB in this preliminary study of 20 patients.RésuméObjectifMalgré les progrès de l’anesthésie, la circulation extracorporelle (CEC) et les techniques chirurgicales, les lésions cérébrales demeurent une importante source de morbidité postchirurgie cardiaque. Les effets neurologiques comparés de l’isoflurane et du propofol sont présentés par l’analyse des protéines sériques S-100ß et des test neuropsychologiques après un pontage aortocoronarien (PAC).MéthodeNotre étude préliminaire, prospective et contrôlée a porté sur 20 patients, répartis au hasard en deux groupes, qui devaient subir un PAC. L’isoflurane a été utilisé dans le groupe I et le propofol dans le groupe P L’examen neurologique et une batterie de tests neuropsychologiques, comprenant le mini-examen de l’état mental (MMSET pour mini mental state examination) et le test visuel et auditif de mémoire des chiffres (VADST pour visual aural digit span test), ont été réalisés avant l’opération et aux jours trois et six postopératoires. Les échantillons sanguins nécessaires à l’analyse des protéines S-100ß ont été prélevés avant l’anesthésie (T1), après l’héparinisation (T2), 15 min après le début de la CEC (T3), après la CEC (T4) et 24 h après l’opération (T5).RésultatsLes examens neurologiques postopératoires étaient normaux. La performance au VADST a décliné significativement au jour trois (P < 0,05) chez tous les patients. Il n’y a pas eu de différence intergroupe significative des scores de VADST et de MMSET. Dans le groupe P, les niveaux de protéines S-100ß ont augmenté à T3 et T4, comparés aux niveaux préopératoires et aux niveaux observés avec l’isoflurane (P < 0,05).ConclusionMalgré des études rapportant les effets neuroprotecteurs du propofol, les niveaux de protéines S-100ß ont été significativement élevés dans le groupe P de notre étude. Aucune détérioration neuropsychologiques n’a été observée, mais le propofol ne semble pas offrir d’avantage sur l’isoflurane pour la protection cérébrale pendant la CEC.

A background infusion of morphine does not enhance postoperative analgesia after cardiac surgery

PurposeTo compare the effects of patient-controlled analgesia (PCA), with or without a background infusion of morphine on postoperative pain relief and stress response after cardiac anesthesia.MethodsWith University Ethics approval, 35 consenting adults undergoing elective open-heart surgery were randomly assigned preoperatively in a double-blind fashion to receive either morphine PCA alone (Group I, n = 15) or morphine PCA plus a continuous basal infusion (Group II, n = 14) for 44 hr postoperatively. Pain scores with visual analogue scale (VAS) at rest, deep inspiration and with cough, sedation scores, stress hormone levels [cortisol, adrenocorticotropin (ACTH) and growth hormone (GH)] and morphine consumption were assessed, and serum morphine levels were measured at four, 20, 28 and 44 hr after surgery. Adverse effects including nausea, vomiting, constipation, urinary retention and pruritus were noted. Total blood, fluid requirements, drainage and urinary output were recorded.ResultsPostoperative morphine consumption at 44 hr was less in Group I (29.43 ±12.57 mg) than in Group II (50.14 ±16.44mg), P = 0.0006. There was no significant difference between groups in VAS scores, GH levels, blood levels of morphine and adverse effects. While VAS scores, ACTH and GH levels decreased significantly in both groups, plasma cortisol levels increased significantly in Group I only at four hours. In Group II, ACTH and cortisol were higher at four and 44 hr respectively.ConclusionPCA with morphine effectively controlled postoperative pain after cardiac surgery. The addition of a background infusion of morphine did not enhance analgesia and increased morphine consumption.RésuméObjectifComparer les effets de l’analgésie autocontrôlée (AAC), avec ou sans une perfusion de morphine de base, sur l’analgésie postopératoire et la réaction de stress à la suite d’une anesthésle cardiaque.MéthodeNotre étude a été menée en double aveugle, avec l’accord du comité d’éthique de l’université, auprès de 35 adultes consentants devant subir une opération à cœur ouvert réglée. Les patients ont reçu, soit de la morphine en AAC seule (Groupe I, n = 15), soit de la morphine en AAC plus une perfusion de base continue (Groupe II, n = 14) pendant 44 h après l’opération. Nous avons évalué: la douleur, au repos, pendant l’inspiration profonde et la toux, selon une échelle visuelle analogique (EVA), la sédation, les niveaux d’hormones de stress [cortisol, les hormones adrénocortlcotropes (ACTH) et de croissance (GH)] et la consommation de morphine, ainsi que les niveaux sériques de morphine à quatre, 20, 28 et 44 h après l’opération. Les effets indésirables, incluant les nausées, les vomissements, la constipation, la rétention urinalre et le prurit ont été notés. Le sang total, les besoins liquidiens, le débit de drainage et la diurèse ont été enregistrés.RésultatsÀ 44 h, la consommation de morphine postopératoire était plus faible dans le Groupe I (29,43 ±12,57 mg) que dans le Groupe II (50,14 ±16,44 mg), P = 0,0006. Il n’y avait pas de différence Intergroupe significative des scores à I’EVA, des niveaux de GH, des niveaux sanguins de morphine et d’effets Indésirables. Les scores à I’EVA, les niveaux d’ACTH et de GH ont diminué slgnificativement dans les deux groupes, mais le cortisol plasmatique a augmenté de façon significative dans le Groupe I, à quatre heures seulement. Dans le Groupe II, l’ACTH et le cortisol étalent respectivement plus élevés à quatre et 44 h.ConclusionL’AAC avec de la morphine réduit efficacement la douleur postopératoire en cardiochirurgie, L’ajout d’une perfusion de base de morphine n’améliore pas l’analgésie, mais augmente la consommatlon de morphine.

Minimum effective dose of dexamethasone after tonsillectomy

Background : The minimum effective dose of dexamethasone in conjunction with 50 μg·kg−1 ondansetron was evaluated in the treatment for vomiting after elective tonsillectomy or adenotonsillectomy.