Influence of various irrigation fluids on serum enzyme patterns following transurethral resection of the prostate

Serum levels of a variety of enzymes were determined preoperatively and repeatedly postoperatively in a comprehensive biochemical study of 60 patients undergoing transurethral resection of the prostate (TURP). These patients were divided into four groups depending on the type of fluid used for irrigation during TURP. Prostatic acid phosphatase (PAP, analysed by radio-immunoassay) in serum showed a marked postoperative increase but wide inter-individual variation in all groups. It returned to normal within 24 to 48 hours. When water was used for irrigation, similar but less pronounced increases were observed for serum lactate dehydrogenase (LD, LD-1) and aminotransferases (ASAT, ALAT). This is interpreted as being due to an influx of irrigating fluid into the general circulation from the bladder through opened veins, by absorption from a perivesical accumulation or, in the case of PAP, also from the prostatic wound. The enzyme increases (other than PAP) may be due to their release from haemolysed red cells in the bladder or in a perivesical fluid accumulation, which conjecture is supported by the marked increase also seen in plasma haemoglobin. When iso-osmolar fluids were used for irrigation signs of haemodilution, such as a postoperative decrease in serum sodium, were observed. Several of the variables studied may be used as markers to indicate the quantity of irrigating fluid absorbed during resection. Plasma haemoglobin, serum LD (or LD-1) in connection with water irrigation, serum sodium in connection with iso-osmolar fluid irrigation and serum PAP, regardless of the type of irrigating fluid used, are some practical suggestions for such markers.