ACTION ON THE HUMAN UTERUS OF ANAESTHETICS AND OTHER DRUGS COMMONLY USED IN LABOUR

Abstract

An apparatus for recording graphically the changes in intra-uterine pressure during labor was used during administration of various anesthetics to nearly 50 patients. The administration of chloroform on an open mask at once arrests the contractions in the 1st stage, and diminishes their force and frequency in the 2nd stage. The effect comes on rapidly, and passes off rapidly when the administration is discontinued. The action of ether is the same as that of chloroform. The administration of gas and O has no effect on the contractions during labor. The intraspinal injection of stovaine does not inhibit the contractions, but interferes with full relaxation between the pains. This appears to be due to continuous contraction of the lower segment, and if stovaine be given early in the 1st stage dilatation will be delayed. Morphine lessens the frequency of uterine contractions, but the pains are prolonged so that the work done by the uterus is probably as great as or greater than before, despite the lessened frequency. Atropine appears to stimulate the contractions of the uterus. It certainly has no inhibitory action. The stimulant action of quinine during labor is very small.