Means for restoring normal circulation in animal bodies in cases where the animal system has been subjected to circulatory shock

摘要

556,862. Respiratory appliances. TRUBENISED, Ltd., and BIHALY, L. April 22, 1942, No. 5406. [Class 81 (ii)] Apparatus for maintaining or restoring normal blood circulation when the circulatory system has been deranged by shock comprises a bag or suit 1 for application to the patient under treatment with means for applying air under pressure to the suit, a breathing mask 7, adapted to be applied at will, connected to the source of air pressure and an automatic valve 6 operating to maintain constant the pressure balance between he tintrathoracic and venous pressures so that the venous pressure is at all times maintained in excess of the intrathoracic pressure by an amount sufficient to ensure satisfactory blood circulation whether the patient is breathing normally at atmospheric pressure or at an adjusted pressure through the mask. As shown a container 2, Figs. 1 & 2, which may be mounted on a wheeled carriage, has an hermetically sealed cover 12 carrying the tubes 4, 7a, a switch 27 for controlling a fan 3 and mountings for the means controlling the valve 6 which is carried by a pivoted lever 16 having an extension engaging a roller 23b on a pivoted lever 23a connected to a rod 20, connected to the ends of bellows 19 arranged on each side of a dome 18 on the cover 12. The rod extends through the end of one of the bellows and carries a roller 21 engaging the face 24 of a weighted lever 23 pivoted on a bracket 22 on the top of the cover 12. By adjusting the weight 26 on the lever 23 the position of the valve 6 is varied to give the required difference of pressures, the valve opening to bypass to the container the air in excess of that required to maintain the desired pressure in the suit during normal periods and ensuring the necessary reduction in pressure in the container during the abnormal periods. A valve 8 on the suit 1 is closed so that during normal periods, while the patient is eating &c., the intrathoracic pressure is atmospheric and the venous pressure is artificially maintained at a slightly higher pressure by the valve 6 ; during abnormal periods, when the patients wounds have to be dressed, the mask is fitted over the mouth and noses' of the patient, the valve 8 is opened so that the pressure in the suit gradually falls to atmospheric, the suit is removed from the patient, and the valve 6 closes to an extent such that the intrathoracic pressure is maintained at the required pressure lower than the venous pressure which is now atmospheric.