Anesthesiology
-
Clinical Trial
Assessment of changes in coagulation in parturients with preeclampsia using thromboelastography.
Preeclampsia is associated with a risk of abnormal hemostasis that occurs most commonly secondary to thrombocytopenia. Thromboelastography measures whole blood coagulation and has been used to manage coagulation defects in obstetric patients. The authors conducted this investigation in a large number of preeclamptic women to assess changes in coagulation using thromboelastography. ⋯ This study shows that severe preeclamptic women with a platelet count <100,000/mm3 are hypocoagulable when compared to healthy pregnant women and other preeclamptic women.
-
Comparative Study
The comparative pharmacodynamics of remifentanil and its metabolite, GR90291, in a rat electroencephalographic model.
The purpose of this study was to investigate the in vivo pharmacodynamics and the pharmacodynamic interactions of remifentanil and its major metabolite, GR90291, in a rat electroencephalographic model. ⋯ Analysis of the data on the basis of a previously postulated, mechanism-based pharmacokinetic-pharmacodynamic model for synthetic opioids revealed that the low in vivo potency of GR90291 can be explained by a low affinity to the mu-opioid receptor in combination with a poor brain penetration.
-
There are no adequate pharmacodynamic data relating concentrations of acetaminophen in serum to analgesia. ⋯ The pharmacodynamics of acetaminophen can be described using a sigmoidal Emax model with a low Hill coefficient. To achieve a mean posttonsillectomy pain score of 3.6 of 10, an effect compartment concentration of 10 mg/l is necessary.
-
Capsaicin, the pungent ingredient in chili peppers, is a vanilloid with noxious and analgesic effects that inhibits tetrodotoxin-resistant sodium currents. Because tetrodotoxin-resistant currents are found primarily in small-diameter nociceptor afferents of the peripheral nerves, their inhibition may lead to selective analgesia. Therefore, the authors evaluated the interactions between tetrodotoxin, a site 1 sodium channel blocker, and capsaicin on nerve blockade in vivo. ⋯ Site 1 sodium channel blockers and vanilloids have synergistic effects on nerve blockade in vivo. These interactions may be useful in developing prolonged local anesthetics and elucidating mechanisms of functionally selective nerve blockade.