Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2005
Randomized Controlled Trial Clinical TrialKetamine sedation during spinal anesthesia for arthroscopic knee surgery reduced the ischemia-reperfusion injury markers.
We studied the effect of ketamine sedation on oxidative stress during arthroscopic knee surgery with tourniquet application by determining blood and tissue malonyldialdehyde (MDA) and hypoxanthine (HPX) levels. Thirty ASA I-II patients undergoing arthroscopic knee surgery with tourniquet were randomly divided into two groups. Spinal anesthesia induced with 12.5 mg bupivacaine was administered to all patients. ⋯ Tissue MDA and HPX levels were significantly less in the ketamine group than the control group after reperfusion. RSS scores were higher in the ketamine group without any adverse effect. We conclude that ketamine sedation attenuates lipid peroxidation markers in arthroscopic knee surgery with tourniquet application.
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Anesthesia and analgesia · Sep 2005
Comparative Study Clinical TrialSpinal anesthesia-induced hypotension: a risk comparison between patients with severe preeclampsia and healthy women undergoing preterm cesarean delivery.
We previously showed that, in comparison with term healthy parturients, patients with severe preeclampsia had a less frequent incidence of spinal hypotension, which was less severe and required less ephedrine. In the present study, we hypothesized that these findings were attributable to preeclampsia-associated factors rather than to a smaller uterine mass. The incidence and severity of hypotension were compared between severe preeclamptics (n = 65) and parturients with preterm pregnancies (n = 71), undergoing spinal anesthesia for cesarean delivery (0.5% bupivacaine, sufentanil, morphine). ⋯ The risk of hypotension in the preeclamptic group was almost 2 times less than that in the preterm group (relative risk = 0.603; 95% confidence interval, 0.362-1.003; P = 0.044). The impact of Apgar scores was minor, and umbilical arterial blood pH was not affected. We conclude that preeclampsia-associated factors, rather than a smaller uterine mass, account for the infrequent incidence of spinal hypotension in preeclamptic patients.
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Anesthesia and analgesia · Sep 2005
Comparative StudyThe myocardial and vascular effects of bupivacaine, levobupivacaine, and ropivacaine using pressure volume loops.
Ropivacaine and levobupivacaine were developed to reduce the risk of fatal accidental overdose reported with bupivacaine. The myocardial depressant potential of these drugs in sublethal dosage is unknown. Pressure volume loops can be used to separate myocardial from vascular effects. ⋯ Ropivacaine increased vascular resistance and reduced EF without effect on contractility. Mean arterial blood pressure and diastolic function were unchanged for all drugs. Significant decline in contractility from control occurs with bupivacaine and levobupivacaine, but not with ropivacaine, at doses achievable in routine clinical practice.
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Anesthesia and analgesia · Sep 2005
Isoflurane-induced neuronal degeneration: an evaluation in organotypic hippocampal slice cultures.
Prolonged exposure of postnatal day (PND) 7 rat pups to anesthetics, which act via N-methyl-D-aspartate antagonism and/or gamma-amino butyric acid enhancement, causes neurodegeneration and persistent behavioral deficits. We studied these findings in vitro and determined whether the age of rat pups used for study or duration of anesthetic exposure modulates resultant neurodegeneration. Organotypic hippocampal slices (OHSs) were prepared from rat pups on PNDs 4, 7, and 14 and cultured 7 or 14 days in vitro. ⋯ Hippocampal CA1, CA3, and dentate gyrus neuronal survival was assessed 3 days later. Neuronal cell death was greatest in OHSs prepared from PND 7 rat pups (P < 0.001) and was most evident after 5 h exposure to isoflurane (P < 0.001). By eliminating variables such as hemodynamics, nutrition, oxygenation, and carbon dioxide elimination, this in vitro investigation supports both an age- and duration-dependent relationship between 1.5% isoflurane exposure and perinatal neuronal death.
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Anesthesia and analgesia · Sep 2005
Predictors of hypotension after induction of general anesthesia.
Hypotension after induction of general anesthesia is a common event. In the current investigation, we sought to identify the predictors of clinically significant hypotension after the induction of general anesthesia. Computerized anesthesia records of 4096 patients undergoing general anesthesia were queried for arterial blood pressure (BP), demographic information, preoperative drug history, and anesthetic induction regimen. ⋯ Smaller doses of propofol, etomidate, and thiopental were not associated with less hypotension. To avoid severe hypotension, alternatives to propofol anesthetic induction (e.g., etomidate) should be considered in patients older than 50 yr of age with ASA physical status > or =3. We conclude that it is advisable to avoid propofol induction in patients who present with baseline MAP <70 mm Hg.