SODIUM NITROPRUSSIDE FOR ANEURYSM SURGERY IN PREGNANCY: Report of a case

A 25-year-old woman in the 7th month of pregnancy was operatedupon for a ruptured cerebral aneurysm. Sodium nitroprussidewas used to achieve effective controlled hypotension. Signsof foetal distress were transient. Subsequent delivery was spontaneousand uneventful. Development of the child at 2 yr was satisfactory.The various physiological aspects and the action of nitroprussideon both mother and foetus are discussed.     

BLUNT TRAUMA TO THE TRACHEA

A 5-year-old child sustained blunt trauma to the cervical trachea.Diffuse subcutaneous emphysema of the neck and thorax developedrapidly. Anaesthesia was induced with halothane through a face-pieceand the patient breathed spontaneously until the lesion hadbeen evaluated. This course is advocated in the management ofsuch injuries.     

PROLONGED EFFECT OF BUPIVACAINE HYDROCHLORIDE AFTER CUFF RELEASE IN I.V. REGIONAL ANAESTHESIA

Bupivacaine hydrochloride 0.25% and 0.50% solutions, were administered115 times by the i.v. regional route to 64 surgical patientsand in 38 subjects suffering from pain syndromes. The clinicaleffects were limb numbness up to 20 h following cuff release,while analgesia and weakness of the limb muscles were evident5 h after the tourniquet. Clinical and electrophysiologicalfindings revealed a dose relationship of the effects. Toxicsigns were noted in three patients in whom the cuff was releasedin a one-step fashion. In 11 patients, mean arterial plasmaconcentrations of bupivacaine reached 3.7 µg ml^–1after administration of 0.5% bupivacaine 40 ml, 5 min afterfinal cuff release, and decreased padually thereafter. In selectedcondinons which do not require a bloodless field and in certainintractable pain states, i.v. regional anaesthesia with high-dosebupivacaine (200 mg of 0.5% solution) may be a simple and effectivetechnique.     

EFFECT OF SODIUM BICARBONATE ON THE KINETICS OF BUPIVACAINE IN I.V. REGIONAL ANAESTHESIA IN DOGS

Changes in pH studied in vitro affected considerably the distributionof bupivacaine between the erythrocytes and incubation medium:in an acidic medium, the uptake of bupivacaine by erythrocyteswas decreased. The acidosis induced in vivo in dogs' limbs duringi.v. regional anaesthesia (IVRA) with bupivacaine was correctedby injecting sodium bicarbonate into the occluded limb. Theconcentration of bupivacaine in the cephalic vein was measuredin dogs under IVRA. After removal of the tourniquet, the drugconcentration-time relationship showed a biexponential patternof decline. Injection of sodium bicarbonate into the limb 10min before the release of the tourniquet suppressed the rateat which the concentration of bupivacaine decreased during thesecond phase. This slower rate of drug release from the tissuesmay prolong residual analgesia.