Changes in intravesical pressure during irrigating fluid absorption in transurethral prostatic surgery.

Continuous recording of intravesical pressure (IVP) and incremental volumetric measurements of irrigating fluid absorption were performed during 37 transurethral resections of the prostate (TUR). Absorption which resulted in concomitant dilutional changes in peripheral blood, indicating intravascular absorption, was associated with prolongation of the time required to increase the IVP. There was an inverse relation between the change in maximum IVP and the rate of irrigating fluid absorption. Absorption that did not result in concomitant dilutional changes in peripheral blood, indicating extravascular absorption, was associated with similar changes in IVP parameters but the critical pressure for absorption was lower.