Anesthesia and analgesia
-
Anesthesia and analgesia · Aug 1997
Comparative StudyRadial artery diameter decreases with increased femoral to radial arterial pressure gradient during cardiopulmonary bypass.
A clinically significant femoral to radial artery pressure gradient sometimes develops during cardiopulmonary bypass (CPB), but the mechanism responsible is not clear. We investigated when the pressure gradient developed and what mechanism could be responsible by comparing mean femoral to mean radial artery pressure and radial artery diameter in 75 male patients undergoing coronary artery bypass grafting. A pressure gradient > or =5 mm Hg (High-P) occurred in 38 patients, and the remaining 37 patients had pressure gradients <5 mm Hg (Low-P) at sternal closure. In High-P group, the pressure gradient was significantly greater (4.8 +/- 3.1 vs 1.0 +/- 3.1 mm Hg; P < 0.001) than in Low-P group, and the ratio of radial artery diameter to the diameter after induction of anesthesia was significantly decreased (0.79 +/- 0.12 vs 0.87 +/- 0.14; P = 0.006) at 5 min after aortic clamping. The pressure gradient and the arterial diameter changes persisted until sternal closure. There was a negative linear correlation between the pressure gradient (deltaP) and the radial artery diameter ratio (D) at sternal closure (D = -15.0deltaP + 16.6, r = 0.39, P < 0.001). In a subgroup of 11 High-P patients, palm temperature was significantly lower (P < 0.05) than that of 11 Low-P patients during and after CPB. We conclude that the femoral to radial artery pressure gradient develops by 5 min after aortic clamping during CPB and persists until sternal closure, and that radial artery constriction could be responsible for the pressure gradient. ⋯ A femoral to radial pressure gradient has been observed after cardiopulmonary bypass. Arterial vasodilation and vasoconstriction have been considered as causes for this gradient. We measured radial artery diameter using pulsed Doppler ultrasound and examined radial artery vasodilation versus vasoconstriction as possible mechanisms for the pressure gradient.
-
Anesthesia and analgesia · Aug 1997
Safe epidural analgesia in thirty parturients with platelet counts between 69,000 and 98,000 mm(-3).
Regional anesthesia is a popular form of pain relief for the management of labor and delivery. Thrombocytopenia is considered a relative contraindication to the administration of regional anesthesia. Some authorities have recommended that an epidural anesthetic be withheld if the platelet count is <100,000 mm(-3). ⋯ Of these 80, 30 had an epidural anesthetic placed when the platelet count was <100,000 mm(-3) (range 69,000-98,000 mm(-3)), 22 had an epidural anesthetic placed with a platelet count >100,000 mm(-3) that subsequently decreased below 100,000 mm(-3), and 28 did not receive a regional anesthetic. We found no documentation of any neurologic complications in the medical records. We conclude that regional anesthesia should not necessarily be withheld when the platelet count is <100,000 mm(-3).
-
Anesthesia and analgesia · Aug 1997
The effects of halothane and isoflurane on the phosphoenergetic state of the liver during hemorrhagic shock in rats: an in vivo 31P nuclear magnetic resonance spectroscopic study.
We studied the effects of halothane versus isoflurane on the phosphoenergetic state and intracellular pH (pHi) of the rat liver using in vivo 31P nuclear magnetic resonance (NMR) spectroscopy during and after hemorrhagic shock. Seventeen rats were anesthetized with 1 minimum alveolar anesthetic concentration of halothane or isoflurane. The mean arterial blood pressure was reduced to 40 mm Hg and maintained at this level for 45 min by withdrawing blood from the common carotid artery. ⋯ Intracellular acidosis was more severe in the halothane group. The recoveries of beta-ATP and P(i) were better in the isoflurane group. Halothane showed a more detrimental effect than isoflurane on the hepatic phosphoenergetic level during and after hemorrhagic shock.