Assessment of White Matter Injury and Outcome in Severe Brain Trauma: A Prospective Multicenter Cohort
; ; et al
in Anesthesiology (2012), 117(6), 1300-1310
BACKGROUND:: Existing methods to predict recovery after severe traumatic brain injury lack accuracy. The aim of this study is to determine the prognostic value of quantitative diffusion tensor imaging ... [more ▼]
BACKGROUND:: Existing methods to predict recovery after severe traumatic brain injury lack accuracy. The aim of this study is to determine the prognostic value of quantitative diffusion tensor imaging (DTI). METHODS:: In a multicenter study, the authors prospectively enrolled 105 patients who remained comatose at least 7 days after traumatic brain injury. Patients underwent brain magnetic resonance imaging, including DTI in 20 preselected white matter tracts. Patients were evaluated at 1 yr with a modified Glasgow Outcome Scale. A composite DTI score was constructed for outcome prognostication on this training database and then validated on an independent database (n = 38). DTI score was compared with the International Mission for Prognosis and Analysis of Clinical Trials Score. RESULTS:: Using the DTI score for prediction of unfavorable outcome on the training database, the area under the receiver operating characteristic curve was 0.84 (95% CI: 0.75-0.91). The DTI score had a sensitivity of 64% and a specificity of 95% for the prediction of unfavorable outcome. On the validation-independent database, the area under the receiver operating characteristic curve was 0.80 (95% CI: 0.54-0.94). On the training database, reclassification methods showed significant improvement of classification accuracy (P < 0.05) compared with the International Mission for Prognosis and Analysis of Clinical Trials score. Similar results were observed on the validation database. CONCLUSIONS:: White matter assessment with quantitative DTI increases the accuracy of long-term outcome prediction compared with the available clinical/radiographic prognostic score. [less ▲]Detailed reference viewed: 16 (2 ULg)
Diffusion Tensor Imaging to Predict Long-term Outcome after Cardiac Arrest: A Bicentric Pilot Study.
; ; et al
in Anesthesiology (2012), 117(6), 1311-1321
BACKGROUND: Prognostication in comatose survivors of cardiac arrest is a major clinical challenge. The authors' objective was to determine whether an assessment with diffusion tensor imaging, a brain ... [more ▼]
BACKGROUND: Prognostication in comatose survivors of cardiac arrest is a major clinical challenge. The authors' objective was to determine whether an assessment with diffusion tensor imaging, a brain magnetic resonance imaging sequence, increases the accuracy of 1 yr functional outcome prediction in cardiac arrest survivors. METHODS:: Prospective, observational study in two intensive care units. Fifty-seven comatose survivors of cardiac arrest underwent brain magnetic resonance imaging. Fractional anisotropy (FA), a diffusion tensor imaging value, was measured in predefined white matter regions, and apparent diffusion coefficient was assessed in predefined grey matter regions. Prediction of unfavorable outcome at 1 yr was compared using four prognostic models: FA global, FA selected, apparent diffusion coefficient, and clinical classifiers. RESULTS:: Of the 57 patients included in the study, 49 had an unfavorable outcome at 12 months. Areas under the receiver operating characteristic curve (95% CI) to predict unfavorable outcome for the FA global, FA selected, clinical, and apparent diffusion coefficient models were 0.92 (0.82-0.98), 0.96 (0.87-0.99), 0.78 (0.65-0.88), and 0.86 (0.74-0.94), respectively. The FA selected model had the best overall accuracy for predicting outcome, with a score above 0.44 having 94% (95% CI, 83-99%) sensitivity and 100% (95% CI, 63-100%) specificity for the prediction of unfavorable outcome. CONCLUSION:: Quantitative diffusion tensor imaging indicates that white matter damage is widespread after cardiac arrest. A prognostic model based on FA values in selected white matter tracts seems to predict accurately 1 yr functional outcome. These preliminary results need to be confirmed in a larger population. [less ▲]Detailed reference viewed: 36 (1 ULg)
Breakdown of within- and between-network resting state functional magnetic resonance imaging connectivity during propofol-induced loss of consciousness.
Boveroux, Pierre ; Vanhaudenhuyse, Audrey ; Bruno, Marie-Aurélie et al
in Anesthesiology (2010), 113(5), 1038-53
BACKGROUND: Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes ... [more ▼]
BACKGROUND: Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes during pharmacological modulation of the level of consciousness. METHODS: Low-frequency spontaneous blood oxygen level-dependent fluctuations were measured in 19 healthy volunteers during wakefulness, mild sedation, deep sedation with clinical unconsciousness, and subsequent recovery of consciousness. RESULTS: Propofol-induced decrease in consciousness linearly correlates with decreased corticocortical and thalamocortical connectivity in frontoparietal networks (i.e., default- and executive-control networks). Furthermore, during propofol-induced unconsciousness, a negative correlation was identified between thalamic and cortical activity in these networks. Finally, negative correlations between default network and lateral frontoparietal cortices activity, present during wakefulness, decreased proportionally to propofol-induced loss of consciousness. In contrast, connectivity was globally preserved in low-level sensory cortices, (i.e., in auditory and visual networks across sedation stages). This was paired with preserved thalamocortical connectivity in these networks. Rather, waning of consciousness was associated with a loss of cross-modal interactions between visual and auditory networks. CONCLUSIONS: Our results shed light on the functional significance of spontaneous brain activity fluctuations observed in functional magnetic resonance imaging. They suggest that propofol-induced unconsciousness could be linked to a breakdown of cerebral temporal architecture that modifies both within- and between-network connectivity and thus prevents communication between low-level sensory and higher-order frontoparietal cortices, thought to be necessary for perception of external stimuli. They emphasize the importance of thalamocortical connectivity in higher-order cognitive brain networks in the genesis of conscious perception. [less ▲]Detailed reference viewed: 123 (11 ULg)
Are blood transfusions associated with greater mortality rates? Results of the Sepsis Occurrence in Acutely Ill Patients study.
; ; et al
in Anesthesiology (2008), 108(1), 31-9
BACKGROUND: Studies have suggested worse outcomes in transfused patients and improved outcomes in patients managed with restricted blood transfusion strategies. The authors investigated the relation of ... [more ▼]
BACKGROUND: Studies have suggested worse outcomes in transfused patients and improved outcomes in patients managed with restricted blood transfusion strategies. The authors investigated the relation of blood transfusion to mortality in European intensive care units (ICUs). METHODS: The Sepsis Occurrence in Acutely Ill Patients study was a multicenter, observational study that included all adult patients admitted to 198 European ICUs between May 1 and May 15, 2002 and followed them until death, until hospital discharge, or for 60 days. Patients were classified depending on whether they had received a blood transfusion at any time during their ICU stay. RESULTS: Of 3,147 patients, 1,040 (33.0%) received a blood transfusion. These patients were older (mean age, 62 vs. 60 yr; P = 0.035) and were more likely to have liver cirrhosis or hematologic cancer, to be a surgical admission, and to have sepsis. They had a longer duration of ICU stay (5.9 vs. 2.5 days; P < 0.001) and a higher ICU mortality rate (23.0 vs. 16.3%; P < 0.001) but were also more severely ill on admission (Simplified Acute Physiology Score II, 40.2 vs. 34.7; P < 0.001; Sequential Organ Failure Assessment score, 6.5 vs. 4.5; P < 0.001). There was a direct relation between the number of blood transfusions and the mortality rate, but in multivariate analysis, blood transfusion was not significantly associated with a worse mortality rate. Moreover, in 821 pairs matched according to a propensity score, there was a higher 30-day survival rate in the transfusion group than in the other patients (P = 0.004). CONCLUSION: This observational study does not support the view that blood transfusions are associated with increased mortality rates in acutely ill patients. [less ▲]Detailed reference viewed: 17 (1 ULg)
Intravenous lidocaine infusion facilitates acute rehabilitation after laparoscopic colectomy
Kaba, Abdourahmane ; ; Detroz, Bernard et al
in Anesthesiology (2007), 106(1), 11-85-6
BACKGROUND: Intravenous infusion of lidocaine decreases postoperative pain and speeds the return of bowel function. The authors therefore tested the hypothesis that perioperative lidocaine infusion ... [more ▼]
BACKGROUND: Intravenous infusion of lidocaine decreases postoperative pain and speeds the return of bowel function. The authors therefore tested the hypothesis that perioperative lidocaine infusion facilitates acute rehabilitation protocol in patients undergoing laparoscopic colectomy. METHODS: Forty patients scheduled to undergo laparoscopic colectomy were randomly allocated to receive intravenous lidocaine (bolus injection of 1.5 mg/kg lidocaine at induction of anesthesia, then a continuous infusion of 2 mg.kg.h intraoperatively and 1.33 mg.kg.h for 24 h postoperatively) or an equal volume of saline. All patients received similar intensive postoperative rehabilitation. Postoperative pain scores, opioid consumption, and fatigue scores were measured. Times to first flatus, defecation, and hospital discharge were recorded. Postoperative endocrine (cortisol and catecholamines) and metabolic (leukocytes, C-reactive protein, and glucose) responses were measured for 48 h. Data (presented as median [25-75% interquartile range], lidocaine vs. saline groups) were analyzed using Mann-Whitney tests. P<0.05 was considered statistically significant. RESULTS: Patient demographics were similar in the two groups. Times to first flatus (17 [11-24] vs. 28 [25-33] h; P<0.001), defecation (28 [24-37] vs. 51 [41-70] h; P=0.001), and hospital discharge (2 [2-3] vs. 3 [3-4] days; P=0.001) were significantly shorter in patients who received lidocaine. Lidocaine significantly reduced opioid consumption (8 [5-18] vs. 22 [14-36] mg; P=0.005) and postoperative pain and fatigue scores. In contrast, endocrine and metabolic responses were similar in the two groups. CONCLUSIONS: Intravenous lidocaine improves postoperative analgesia, fatigue, and bowel function after laparoscopic colectomy. These benefits are associated with a significant reduction in hospital stay. [less ▲]Detailed reference viewed: 118 (3 ULg)
Naloxone-insensitive epidural placebo analgesia in a chronic pain patient.
; ; Boly, Mélanie et al
in Anesthesiology (2007), 106(6), 1239-42Detailed reference viewed: 19 (0 ULg)
Implicit memory during isoflurane anesthesia - Reply
; Willems, Sylvie
in Anesthesiology (2006), 105(2), 430-430Detailed reference viewed: 33 (6 ULg)
Effect of nutritional status on oxidative stress in an ex vivo perfused rat liver
; ; Seidel, Laurence et al
in Anesthesiology (2005), 103(5), 978-986
Background: Normothermic ischemia-reperfusion is a determinant in liver injury occurring during surgical procedures, ischemic state, and multiple organ failure. The preexisting nutritional status of the ... [more ▼]
Background: Normothermic ischemia-reperfusion is a determinant in liver injury occurring during surgical procedures, ischemic state, and multiple organ failure. The preexisting nutritional status of the liver might contribute to the extent of tissue injury and primary nonfunction. The aim of this study was to determine the role of starvation on hepatic ischemia-raperfusion injury in normal rat livers. Methods: Rats were randomly divided into two groups: one had free access to food, the other was fasted for 16 h. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Two modes of perfusion were applied in each series of rats, fed and fasting. In the ischemia-reperfusion mode, the experiment consisted of perfusion for 15 min, warm ischemia for 60 min, and reperfusion during 60 min. In the nonischemia mode, perfusion was maintained during the 135-min study period. Five rats were included in each experimental condition, yielding a total of 20 rats. Liver enzymes, potassium, glucose, lactate, free radicals, ie., dienes and trienes, and cytochrome c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in tissue biopsies. Results: Transaminases, lactate dehydrogenase, potassium, and free radical concentrations were systematically higher in fasting rats in both conditions, with and without ischemia. Cytochrome c was higher after reperfusion in the fasting rats. Glucose and lactate concentrations were greater in the fed group. The glycogen content decreased in both groups during the experiment but was markedly lower in the fasting rats. Conclusions: In fed rats, liver injury was moderate, whereas hepatocytes integrity was notably impaired both after continuous perfusion and warm ischemia in fasting animals. Reduced glycogen store in hepatocytes may explain reduced tolerance. [less ▲]Detailed reference viewed: 13 (1 ULg)
Investigation of automatic memory during general anesthesia for elective surgery using the process dissociation procedure
Willems, Sylvie ; ; et al
in Anesthesiology (2005), 103
Background: This prospective study evaluated memory function during general anesthesia for elective surgery and its relation to depth of hypnotic state. The authors also compared memory function in ... [more ▼]
Background: This prospective study evaluated memory function during general anesthesia for elective surgery and its relation to depth of hypnotic state. The authors also compared memory function in anesthetized and nonanesthetized subjects. Methods: Words were played for 70 min via headphones to 48 patients (aged 18–70 yr) after induction of general anesthesia for elective surgery. Patients were unpremedicated, and the anesthetic regimen was free. The Bispectral Index (BIS) was recorded throughout the study. Within 36 h after the word presentation, memory was assessed using an auditory word stem completion test with inclusion and exclusion instructions. Memory performance and the contribution of explicit and implicit memory were calculated using the process dissociation procedure. The authors applied the same memory task to a control group of nonanesthetized subjects. Results: Forty-seven patients received isoflurane, and one patient received propofol for anesthesia. The mean ( SD) BIS was 49 9. There was evidence of memory for words presented during light (BIS 61–80) and adequate anesthesia (BIS 41–60) but not during deep anesthesia (BIS 21–40). The process dissociation procedure showed a significant implicit memory contribution but not reliable explicit memory contribution (mean explicit memory scores 0.05 0.14, 0.04 0.09, and 0.05 0.14; mean automatic influence scores 0.14 0.12, 0.17 0.17, and 0.18 0.21 at BIS 21–40, 41–60, and 61–80, respectively). Compared with anesthetized patients, the memory performance of nonanesthetized subjects was better, with a higher contribution by explicit memory and a comparable contribution by implicit memory. Conclusion: During general anesthesia for elective surgery, implicit memory persists even in adequate hypnotic states, to a comparable degree as in nonanesthetized subjects. [less ▲]Detailed reference viewed: 56 (8 ULg)
Difference in risk factors for postoperative nausea and vomiting.
; Bardiau, Françoise ; Seidel, Laurence et al
in Anesthesiology (2003), 98(1), 46-52
BACKGROUND: It is commonly stated that risk factors for postoperative nausea are the same as for vomiting. The authors designed a prospective study to identify and differentiate the risk factors for ... [more ▼]
BACKGROUND: It is commonly stated that risk factors for postoperative nausea are the same as for vomiting. The authors designed a prospective study to identify and differentiate the risk factors for postoperative nausea and vomiting in various surgical populations in a clinical audit setting. METHODS: The study included 671 consecutive surgical inpatients, aged 15 yr or more, undergoing various procedures. The study focused on postoperative nausea visual analog scale scores every 4 h and vomiting episodes within 72 h. Both vomiting and retching were considered as emetic events. Patient-, anesthesia-, and surgery-related variables that were considered to have a possible effect on the proportion of patients experiencing postoperative nausea and/or vomiting were examined. The bivariate Dale model for binary correlated outcomes was used to identify selectively the potential risk factors of postoperative nausea and vomiting. RESULTS: Among the 671 patients in the study, 126 (19%) reported one or more episodes of nausea, and 66 patients (10%) suffered one or more emetic episodes during the studied period. There was a highly significant association between the two outcomes. Some risk factors were predictive of both nausea and vomiting (female gender, nonsmoking status, and general anesthesia). History of migraine and type of surgery were mainly responsible for nausea but not for vomiting. The predictive effect of risk factors was controlled for postoperative pain and analgesic drugs. CONCLUSION: This study shows that differences exist in risk factors of postoperative nausea and vomiting. These could be explained by differences in the physiopathology of the two symptoms. [less ▲]Detailed reference viewed: 14 (0 ULg)
Randomized Trial of Diaspirin Cross-Linked Hemoglobin Solution as an Alternative to Blood Transfusion after Cardiac Surgery. The Dclhb Cardiac Surgery Trial Collaborative Group
Lamy, Maurice ; ; Brichant, Jean-François et al
in Anesthesiology (2000), 92(3), 646-56
BACKGROUND: Risks associated with transfusion of allogeneic blood have prompted development of methods to avoid or reduce blood transfusions. New oxygen-carrying compounds such as diaspirin cross-linked ... [more ▼]
BACKGROUND: Risks associated with transfusion of allogeneic blood have prompted development of methods to avoid or reduce blood transfusions. New oxygen-carrying compounds such as diaspirin cross-linked hemoglobin (DCLHb) could enable more patients to avoid allogeneic blood transfusion. METHODS: The efficacy, safety, hemodynamic effects, and plasma persistence of DCLHb were investigated in a randomized, active-control, single-blind, multicenter study in post-cardiac bypass surgery patients. Of 1,956 screened patients, 209 were determined to require a blood transfusion and met the inclusion criteria during the 24-h post-cardiac bypass period. These patients were randomized to receive up to three 250-ml infusions of DCLHb (n = 104) or three units of packed erythrocytes (pRBCs; n = 105). Further transfusions of pRBCs or whole blood were permitted, if indicated. Primary efficacy end points were the avoidance of blood transfusion through hospital discharge or 7 days postsurgery, whichever came first, and a reduction in the number of units of pRBCs transfused during this same time period. Various laboratory, physiologic, and hemodynamic parameters were monitored to define the safety and pharmacologic effect of DCLHb in this patient population. RESULTS: During the period from the end of cardiopulmonary bypass surgery through postoperative day 7 or hospital discharge, 20 of 104 (19%) DCLHb recipients did not receive a transfusion of pRBCs compared with 100% of control patients (P < 0.05). The overall number of pRBCs administered during the 7-day postoperative period was not significantly different. Mortality was similar between the DCLHb (6 of 104 patients) and the control (8 of 105 patients) groups. Hypertension, jaundice/hyperbilirubinemia, increased serum glutamic oxalo-acetic transaminase, abnormal urine, and hematuria were reported more frequently in the DCLHb group, and there was one case of renal failure in each group. The hemodynamic effects of DCLHb included a consistent and slightly greater increase in systemic and pulmonary vascular resistance with associated increases in systemic and pulmonary arterial pressures compared with pRBC. Cardiac output values decreased more in the DCLHb group patients after the first administration than the control group patients. At 24 h postinfusion, the plasma hemoglobin level was less than one half the maximal level for any amount of DCLHb infused. CONCLUSIONS: Administration of DCLHb allowed a significant number (19%) of cardiac surgery patients to avoid exposure to erythrocytes postoperatively. [less ▲]Detailed reference viewed: 38 (13 ULg)
Neural mechanisms of antinociceptive effects of hypnosis.
Faymonville, Marie ; Laureys, Steven ; Degueldre, Christian et al
in Anesthesiology (2000), 92(5), 1257-67
BACKGROUND: The neural mechanisms underlying the modulation of pain perception by hypnosis remain obscure. In this study, we used positron emission tomography in 11 healthy volunteers to identify the ... [more ▼]
BACKGROUND: The neural mechanisms underlying the modulation of pain perception by hypnosis remain obscure. In this study, we used positron emission tomography in 11 healthy volunteers to identify the brain areas in which hypnosis modulates cerebral responses to a noxious stimulus. METHODS: The protocol used a factorial design with two factors: state (hypnotic state, resting state, mental imagery) and stimulation (warm non-noxious vs. hot noxious stimuli applied to right thenar eminence). Two cerebral blood flow scans were obtained with the 15O-water technique during each condition. After each scan, the subject was asked to rate pain sensation and unpleasantness. Statistical parametric mapping was used to determine the main effects of noxious stimulation and hypnotic state as well as state-by-stimulation interactions (i.e., brain areas that would be more or less activated in hypnosis than in control conditions, under noxious stimulation). RESULTS: Hypnosis decreased both pain sensation and the unpleasantness of noxious stimuli. Noxious stimulation caused an increase in regional cerebral blood flow in the thalamic nuclei and anterior cingulate and insular cortices. The hypnotic state induced a significant activation of a right-sided extrastriate area and the anterior cingulate cortex. The interaction analysis showed that the activity in the anterior (mid-)cingulate cortex was related to pain perception and unpleasantness differently in the hypnotic state than in control situations. CONCLUSIONS: Both intensity and unpleasantness of the noxious stimuli are reduced during the hypnotic state. In addition, hypnotic modulation of pain is mediated by the anterior cingulate cortex. [less ▲]Detailed reference viewed: 115 (8 ULg)
Relationships between pain indicators derived from VAS measurements and analgesics consumption
; SEIDEL, Laurence ; Albert, Adelin et al
in Anesthesiology (1999)Detailed reference viewed: 4 (0 ULg)
Perioperative sympatholysis. Beneficial effects of the a2-adrenoceptor agonist mivazerol on hemodynamic stability and myocardial ischemia
Larbuisson, Robert ; Lamy, Maurice ;
in Anesthesiology (1997), 86Detailed reference viewed: 13 (0 ULg)
Is aprotinin worth the risk in total hip replacement?
Janssens, Marc ; Joris, Jean
in Anesthesiology (1994), 81(2), 518-519Detailed reference viewed: 8 (0 ULg)
Epidural anesthesia impairs both central and peripheral thermoregulatory control during general anesthesia.
Joris, Jean ; ; et al
in Anesthesiology (1994), 80(2), 268-77
BACKGROUND: The authors tested the hypotheses that: (1) the vasoconstriction threshold during combined epidural/general anesthesia is less than that during general anesthesia alone; and (2) after ... [more ▼]
BACKGROUND: The authors tested the hypotheses that: (1) the vasoconstriction threshold during combined epidural/general anesthesia is less than that during general anesthesia alone; and (2) after vasoconstriction, core cooling rates during combined epidural/general anesthesia are greater than those during general anesthesia alone. Vasoconstriction thresholds and heat balance were evaluated under controlled circumstances in volunteers, whereas the clinical importance of intraoperative thermoregulatory vasoconstriction was evaluated in patients. METHODS: Five volunteers were each evaluated twice. On one of the randomly ordered days, epidural anesthesia (approximately T9 dermatomal level) was induced and maintained with 2-chloroprocaine. On both study days, general anesthesia was induced and maintained with isoflurane (0.7% end-tidal concentration), and core hypothermia was induced by surface cooling and continued for at least 1 h after fingertip vasoconstriction was observed. Patients undergoing colorectal surgery were randomly assigned to combined epidural/enflurane anesthesia (n = 13) or enflurane alone (n = 13). In appropriate patients, epidural anesthesia was maintained by an infusion of bupivacaine. The core temperature that triggered fingertip vasoconstriction identified the threshold. RESULTS: In the volunteers, the vasoconstriction threshold was 36.0 +/- 0.2 degrees C during isoflurane anesthesia alone, but significantly less, 35.1 +/- 0.7 degrees C, during combined epidural/isoflurane anesthesia. Cutaneous heat loss and the rates of core cooling were similar 30 min before vasoconstriction with and without epidural anesthesia. In the 30 min after vasoconstriction, heat loss decreased 33 +/- 13 W when the volunteers were given isoflurane alone, but only 8 +/- 16 W during combined epidural/isoflurane anesthesia. Similarly, the core cooling rates in the 30 min after vasoconstriction were significantly greater during combined epidural/isoflurane anesthesia (0.8 +/- 0.2 degrees C/h) than during isoflurane alone (0.2 +/- 0.1 degrees C/h). In the patients, end-tidal enflurane concentrations were slightly, but significantly, less in the patients given combined epidural/enflurane anesthesia (0.6 +/- 0.2% vs. 0.8 +/- 0.2%). Nonetheless, the vasoconstriction threshold was 34.5 +/- 0.6 degrees C in the epidural/enflurane group, which was significantly less than that in the other patients, 35.6 +/- 0.8 degrees C. When the study ended after 3 h of anesthesia, patients given combined epidural/enflurane anesthesia were 1.2 degrees C more hypothermic than those given general anesthesia alone. The rate of core cooling during the last hour of the study was 0.4 +/- 0.2 degrees C/h during combined epidural/enflurane anesthesia, but only 0.1 +/- 0.3 degrees C/h during enflurane alone. CONCLUSIONS: These data indicate that epidural anesthesia reduces the vasoconstriction threshold during general anesthesia. Furthermore, the markedly reduced rate of core cooling during general anesthesia alone illustrates the importance of leg vasoconstriction in maintaining core temperature. [less ▲]Detailed reference viewed: 35 (0 ULg)
High-dose aprotinin reduces blood loss in patients undergoing total hip replacement surgery
Janssens, Marc ; Joris, Jean ; et al
in Anesthesiology (1994), 80Detailed reference viewed: 10 (1 ULg)
Clonidine and ketanserin both are effective treatment for postanesthetic shivering.
Joris, Jean ; ; et al
in Anesthesiology (1993), 79(3), 532-9
BACKGROUND: Although meperidine is an effective treatment of postanesthetic shivering, its mechanism of action remains unknown. Investigation of other drugs might help clarify the mechanisms by which ... [more ▼]
BACKGROUND: Although meperidine is an effective treatment of postanesthetic shivering, its mechanism of action remains unknown. Investigation of other drugs might help clarify the mechanisms by which shivering can be controlled. Accordingly, we investigated the efficacy of clonidine, an alpha 2-adrenergic agonist, and ketanserin, a 5-hydroxytryptamine antagonist, in treating postanesthetic shivering. METHODS: First, 54 patients shivering after general anesthesia were allocated randomly to receive an intravenous bolus of saline, 150 micrograms clonidine, or 10 mg ketanserin. A second study explored the dose-dependence of clonidine. Forty shivering patients were given saline or clonidine, 37.5, 75, or 150 micrograms. RESULTS: The duration of shivering was significantly shorter in those given clonidine (2.1 +/- 0.9 min) than in the other two groups and shorter in the ketanserin group (4.3 +/- 0.9 min) than in the saline group (12.0 +/- 1.6 min). Clonidine and ketanserin significantly decreased systolic arterial blood pressure when compared to saline. Core rewarming was significantly slower in the clonidine group. In the second study, 37.5 micrograms clonidine was no more effective than saline. Two minutes after treatment, 150 micrograms obliterated shivering in all patients. Five minutes after treatment, all patients given 75 micrograms had stopped shivering. Systolic arterial pressure and heart rate decreased significantly in patients given 75 and 150 micrograms clonidine. CONCLUSIONS: Clonidine (150 micrograms) and ketanserin (10 mg) both are effective treatment for postanesthetic shivering. The effect of clonidine on shivering is dose-dependent: whereas 37.5 micrograms had no effect, 75 micrograms clonidine stopped shivering within 5 min. [less ▲]Detailed reference viewed: 30 (1 ULg)
Halothane, enflurane, and isoflurane depress the peripheral vagal motor pathway in isolated canine tracheal smooth muscle.
Brichant, Jean-François ; ; et al
in Anesthesiology (1991), 74(2), 325-32
Volatile anesthetics are potent bronchodilators, but the site of action for the dilation is unclear. To determine the site of action of halothane, enflurane, and isoflurane on the peripheral vagal motor ... [more ▼]
Volatile anesthetics are potent bronchodilators, but the site of action for the dilation is unclear. To determine the site of action of halothane, enflurane, and isoflurane on the peripheral vagal motor pathway, isolated strips of canine trachealis muscle were stimulated before and during exposure to halothane at 0.3, 1.0, 1.7, or 2.4 MAC, enflurane at 1 MAC, or isoflurane at 1 MAC. The sites and methods of stimulation were: 1) postsynaptic nicotinic cholinergic receptors in the intramural parasympathetic ganglia, with 1,1-dimethyl-4-phenyl-piperazinium iodide (DMPP); 2) postganglionic cholinergic nerve fibers, with electrical field stimulation (EFS); and 3) muscarinic cholinergic receptors of the smooth muscle, with acetylcholine (ACh). The concentration-response curve to DMPP was significantly shifted to the right by 0.3 MAC halothane, whereas 0.3 MAC halothane had no significant effect on the concentration-response curves to ACh and EFS. At concentrations greater than 1 MAC of halothane, enflurane, or isoflurane, concentration-response curves to all three stimuli were shifted significantly to the right; i.e., the contractile responses to ACh, EFS, and DMPP were reduced. At all concentrations of halothane the force of contraction was significantly more reduced during stimulation with DMPP than during stimulation with ACh, and at halothane concentrations greater than or equal to 1.7 MAC the response to EFS was significantly more reduced than that to ACh. We conclude that halothane, enflurane, and isoflurane attenuated airway constriction by several mechanisms, including 1) reduced excitability of the postsynaptic nicotinic receptors of the intramural parasympathetic ganglia and 2) an effect on the smooth muscle and/or on the muscarinic receptors.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]Detailed reference viewed: 17 (0 ULg)