VISUAL CHANGES AFTER TRANSURETHRAL RESECTION OF THE
PROSTATE (also see Chapter
54
)
Clinical Significance
Visual changes associated with transurethral resection of the
prostate (TURP) have been recognized for nearly
40 years.[248]
[249]
[250]
[251]
[252]
[253]
[254]
[255]
[256]
[257]
These
changes can occur alone or as part of a syndrome involving excessive absorption of
irrigating fluid with subsequent hyponatremia, cerebral edema, seizures, coma, and
cardiac failure from fluid overload.[252]
Although
the use of TURP is declining because of economic and regulatory constraints, as well
as the development of noninvasive alternatives,[258]
complications still occur. Fluid absorption and visual disturbances have also been
reported after hysteroscopy.[259]
Successful completion of TURP requires copious irrigation of the
bladder to remove clots and debris and keep the surgeon's view of the field clear.
Despite aspiration of the irrigant, 1 L or more may be absorbed by the patient[260]
at a rate of approximately 10 to 30 mL/min,[261]
but rates as high as 200 mL/min have been reported.[262]
Absorption of the irrigant is the major source of nonsurgically related complications.
Determinants of the amount of irrigant absorbed include the duration of the resection,
the extent of opening the prostatic venous sinuses, the hydrostatic pressure of the
irrigation fluid, and venous pressure at the "irrigant-blood interface."[263]
However, Hamilton-Stewart and Barlow dispute the role of operative time; they found
that a longer resection time did not increase absorption. The veins and capsule
of a smaller prostate may be exposed earlier in the resection, so greater absorption
during a quick resection leads to the same amount of irrigant absorption as slower
absorption during a long resection.[264]
Nonetheless,
significant amounts of absorption may occur even if the surgeon believes that no
venous sinuses are open, and the operator thus cannot predict or estimate how much
has been absorbed.[265]
Absorption of irrigating
fluid may continue postoperatively through the retroperitoneal and perivesical spaces.
[266]
Vigilance and a high index of suspicion for
development of the syndrome are important components of the anesthetic plan. The
possibility of earlier detection of central nervous system (CNS) signs and symptoms
of TURP syndrome accounts for the preference by many for regional anesthesia for
these procedures.
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