Acta anaesthesiologica Scandinavica
-
Acta Anaesthesiol Scand · Oct 1988
Randomized Controlled Trial Clinical TrialLower limb compression using inflatable splints to prevent hypotension during spinal anaesthesia for caesarean section.
The efficacy of pneumatic compression of the lower limbs using inflatable leg splints in prevention of hypotension during spinal anaesthesia was assessed in an open study of 46 patients undergoing elective caesarean section. All patients received 15 ml/kg of Hartmann's solution before spinal anaesthesia and were tilted to the left to minimise aortocaval compression. ⋯ Blood pressure was measured by a cuff method at 1-min intervals until the commencement of surgery. Hypotension was less common (P less than 0.05) and less severe (P less than 0.05) in splint-treated patients, but the incidence was unacceptably high in both treated (48%) and control (83%) groups.
-
Acta Anaesthesiol Scand · Oct 1988
Pharmacokinetics and protein binding of bupivacaine in postoperative epidural analgesia.
We describe a method, which is both specific and rapid, for the measurement of bupivacaine concentrations in plasma using high-performance liquid chromatography. Bupivacaine plasma concentrations, pharmacokinetics and protein binding in the postoperative period were investigated in seven patients (58-77 years old) following hip surgery. Postoperative analgesia was achieved by epidural bolus injections of 25 mg bupivacaine 0.25% every 6 h. ⋯ The free fraction decreased from 5.4% preoperatively to 2.7% in the postoperative period (P less than 0.05). Changes in plasma protein binding of bupivacaine and changes in plasma levels of the acute phase reactant alpha-1-acid glycoprotein were correlated (r = 0.8, P less than 0.05). Difficulties in interpreting the elimination parameters following epidural administration are discussed, leading to the conclusion that the derivation of dosage regimens from kinetic parameters following epidural administration is not warranted.
-
Acta Anaesthesiol Scand · Oct 1988
Vasopressor therapy for hypotension due to epidural anesthesia for cesarean section.
Maternal hemodynamic changes and neonatal acid-base status were assessed in 127 healthy patients undergoing elective cesarean section under epidural anesthesia. An impedance cardiograph was used to measure stroke volume (SV), ejection fraction (EF) and end-diastolic volume (EDV). In addition, neonatal umbilical venous and arterial PO2, PCO2, pH, base excess, lactate, pyruvate, excess lactate, and L/P ratio were measured at birth. ⋯ Both vasopressors restored BP, SV and EDV to near baseline values. Neonatal Apgar scores and acid-base profiles were not significantly different among the three groups of neonates, nor were they different between the two hypotensive groups. It is concluded that: 1) transient maternal hypotension does not affect neonatal acid-base status; 2) both ephedrine and phenylephrine increase cardiac preload; and 3) an alpha agent like phenylephrine does not cause fetal acidosis when used for treating maternal hypotension.
-
Acta Anaesthesiol Scand · Oct 1988
Comparative StudyPrimary evaluation of the local anaesthetic properties of the amino amide agent ropivacaine (LEA 103).
The local anaesthestic properties of 1-propyl-2',6'-pipecoloxylidide, a congener of mepivacaine and bupivacaine, and its enantiomers were compared in animals. The (S)-enantiomer (ropivacaine, LEA 103) produced a longer duration of sciatic nerve block and infiltration anaesthesia than the racemate and the (R)-form. Ropivacaine and bupivacaine were equally potent in terms of block of evoked action potential in vitro and minimum effective concentration in vivo. ⋯ Ropivacaine was less toxic (i.v. and s.c. LD50-values) than bupivacaine but more toxic than lidocaine, and produced only weak local irritation. Due to a combination of interesting local anaesthetic properties and relative safety including cardiotoxic potential, we consider ropivacaine a candidate for further studies.
-
Acta Anaesthesiol Scand · Oct 1988
Letter Comparative StudyEpidural versus combined spinal epidural block for caesarean section.