Anesthesia and analgesia
-
Anesthesia and analgesia · Oct 2001
Case ReportsPractical issues in bispectral analysis of electroencephalographic signals.
The aim of this report was to confirm the methodology of bispectral analysis of electroencephalogram. In developing a software for real-time bispectral analysis, we encountered several practical problems in bispectrum calculation. We settled those and concluded that 3 min of monitoring are required to obtain reliable and reproducible bicoherence values.
-
Anesthesia and analgesia · Oct 2001
Isoproterenol enhances myofilament Ca(2+) sensitivity during hypothermia in isolated guinea pig beating hearts.
Isoproterenol is often required to treat acute left ventricular dysfunction during separation from cardiopulmonary bypass for cardiac surgery. We hypothesized that heart rate and intracellular Ca(2+) concentration ([Ca(2+)]i) homeostasis may be important factors when isoproterenol improves the cardiac function during hypothermia. Accordingly, we investigated the effect of isoproterenol on the cardiac functional variables, [Ca(2+)]i, and myofilament Ca(2+) sensitivity under spontaneous beating during hypothermia. Intact guinea pig hearts were perfused with a modified Krebs-Ringer solution (baseline) and Krebs-Ringer solution containing isoproterenol (1 nM) at 37 degrees C, 32 degrees C, and 27 degrees C while all cardiac variables and [Ca(2+)]i were recorded. Isoproterenol increased developed left ventricular pressure (LVP), maximum rate of increase in LVP, and coronary inflow at 27 degrees C, and it also increased heart rate and maximum rate of decrease in LVP at each temperature (P < 0.05). Isoproterenol produced a leftward shift of the curve of developed LVP as a function of available [Ca(2+)]i at 32 degrees C and 27 degrees C (P < 0.05), without changing available [Ca(2+)]i. Isoproterenol improves the cardiac function, especially systolic ventricular function, by enhancement of myofilament Ca(2+) sensitivity under spontaneous beating during hypothermia in intact guinea pig hearts. ⋯ Enhancement of myofilament Ca(2+) sensitivity is involved in the improvement of cardiac function by isoproterenol under spontaneous beating during hypothermia.
-
Anesthesia and analgesia · Oct 2001
Clinical TrialHemostatic changes in pediatric neurosurgical patients as evaluated by thrombelastograph.
Thromboembolic events are a known complication in neurosurgical patients. There is evidence to suggest that a hypercoagulable state may develop perioperatively. Thrombelastograph (TEG) coagulation analysis is a reliable method of evaluating hypercoagulability. We evaluated coagulation by using TEG data in pediatric neurosurgical patients undergoing craniotomy to determine whether a hypercoagulable state develops intraoperatively or postoperatively. Thirty children undergoing craniotomy for removal of a tumor or seizure focus were studied. Blood was analyzed with TEG) data by using native and celite techniques, at three time points for each patient: preoperatively after induction of anesthesia; intraoperatively during closure of the dura; and on the first postoperative day. Compared with preoperative indices, closing and postoperative celite TEG values were indicative of hypercoagulability with shortened coagulation time values (P < 0.001), prolonged alpha angle divergence values (P < 0.001), and above-normal TEG coagulation indices (P < or = 0.002). Reaction time values were shortened, and maximal amplitude of clot strength values were prolonged but did not reach statistical significance. Hypercoagulation develops early after resection of brain tissue in pediatric neurosurgical patients as assessed by using TEG data. Further studies are needed to determine the clinical significance of this hypercoagulable state. ⋯ Hypercoagulability in postoperative neurosurgical patients has been demonstrated in the adult population, but few studies have dealt with the pediatric population. We found that children undergoing craniotomy for focal resection, lobectomy, and hemispherectomy are hypercoagulable as detected by thrombelastograph coagulation analysis. Further studies are needed to determine whether this is clinically significant.
-
Anesthesia and analgesia · Oct 2001
Case ReportsThe anesthetic management of a case of tracheogastric fistula.
A 68-yr-old man developed a tracheogastric fistula after esophageal resection with gastric interposition. We report the anesthetic management of this patient undergoing tracheal repair and fistula closure.
-
Anesthesia and analgesia · Oct 2001
Case ReportsThe long-term antinociceptive effect of intrathecal S(+)-ketamine in a patient with established morphine tolerance.
Our report describes for the first time the continuous long-term intrathecal application of S(+)-ketamine in a patient with chronic pain and morphine tolerance. Intrathecally applied S(+)-ketamine led to a significant pain reduction and consecutively reduced the doses of intrathecal morphine required for pain relief even several weeks after the cessation of the 24-day period of intrathecal S(+)-ketamine administration.