This disclosure relates to the determination of blood loss during endoscopic operations, particularly, during transurethral resectomy. It is known in such operations to employ continuous irrigation using sterilized water which is fed into the body cavity through the endoscope and fed out again mixed with the lost blood. According to the disclosure a method is provided wherein the specific blood content is found from one of the characteristics of the outgoing water which alters with the blood content: to determine the blood lost this specific blood content is compared with the rate of flow of the monitored outgoing flushing water.
Apparatus for continuously monitoring the loss of blood suffered by a patient in the course of a surgical operation. The apparatus provides a means for sucking the combination of blood and irrigating solution gathered about the incision, and for sequentially measuring the volumes and densities of small samplings of the solution-and-blood mixture being drawn through the conduit leading from the incision area to the suction device. The apparatus relies on the difference between the respective densities of the blood and of the irrigating solution in order to calculate the exact volume of blood contained in each sampling. The blood loss is continuously accumulated and displayed on a visual read-out, so that a corresponding amount of blood can be transfused to the patient in order to maintain his blood pressure throughout the operation. The apparatus can be operated in a calibration mode, under which blood, then solution, are measured separately to determine their respective densities which will be used in the quantitative analysis of the mixture. A scale is also provided to weigh sponges, linen etc. which have absorbed blood or some of the blood-and-solution mixture during the surgery. The corresponding calculated volume of blood which they carry is automatically added to the cumulative figure of lost blood.
An isomolar solution of glycerol and water containing glycerol in the amount of about 2.75 weight percent is provided as a non-cytotoxic, non-hemolytic, non-viscid, non-conductive and optically clear surgical irrigation solution.
The present disclosure describes a method called the rinse test for determining where silver is being lost and the variability of this loss in a photographic emulsion manufacturing process. Results from this method can be used to determine what parts of the emulsion manufacturing process should be improved to increase silver yield thereby reducing manufacturing costs and what parts of the emulsion manufacturing process should be improved to reduce silver loss variability thereby improving an emulsion's sensitometric response. The photographic emulsion manufacturing process includes at least one kettle and a plurality of processing equipment which may include sections of pipe, permeators, mixers and pumps. The silver loss is determined by adding water to a kettle after the product has been removed from but prior to cleaning of this kettle. The concentration of silver in this rinse water is measured and the amount of silver is determined. Each piece of processing equipment is flushed sequentially with water from this kettle and the concentration of silver in this rinse water is measured after each piece is flushed. The amount of silver in the receiving kettle is determined then the silver loss in each piece of processing equipment is determined from the incremental increase of the total silver in this rinse water.
