EFFECTS OF KETAMINE ON THE PREGNANT UTERUS

Intra-uterine pressure was recorded by placing a Foley catheterin the extra-amniotic space before the termination of pregnancyin 25 patients, and Caesarean section in 12 patients. The effectsof administration of i.v. ketamine 2 mg/kg body weight, sodiumthiopentone 4 mg/kg body weight and ergometrine 0.5 mg, andintra-cervical 0·5% lignocaine 20 ml were measured inthe first trimester of pregnancy, and i.v. ketamine and sodiumthiopentone in late pregnancy. Ketamine was found to cause uterinecontraction (mean increase 16.1 mm Hg) equal to ergometrine(mean increase 14.8 mm Hg) in early pregnancy, but exert noeffect (mean decrease -1.33 mm Hg) in late pregnancy. Lignocainein early pregnancy given as a paracervical block had no significanteffect on intra-uterine pressure (mean increase 0.33 mm Hg).Sodium thiopentone (mean decrease -4.28 mm Hg first trimesterand -2.22 mm Hg at term) in late pregnancy had no significanteffect on intra-uterine pressure.