Detrusor activity is impaired during thoracic epidural analgesia after open renal surgery.
BACKGROUND
There are no data on lower urinary tract function during postoperative thoracic epidural analgesia (TEA). Because selected segmental blockade can be achieved with epidural analgesia, we hypothesized that lower urinary tract function remains unchanged during TEA within segments T4-T11 after open renal surgery.


METHODS
In a prospective, open, observational, follow-up study, 13 male patients with no preexisting lower urinary tract symptoms (International Prostate Symptom Score < or =7) and postvoid residual less than 100 ml underwent urodynamic investigations the day before open renal surgery (lumbotomy) and 2-3 days postoperatively during TEA. Primary outcome was the difference in postvoid residual before versus after surgery during TEA.


RESULTS
The median postvoid residual increased from 25 ml before surgery (range, 0-95) to 420 ml (15-1020) 2-3 days postoperatively (P = 0.002). Maximum detrusor pressure, detrusor pressure at maximum flow rate, and maximum flow rate were significantly reduced during TEA (37 [28-84] to 27 cm H2O [13-51], P = 0.004; 31 [27-52] to 19 cm H2O [0-33], P = 0.003; and 14 [4-35] to 4 ml/s [0-13], P = 0.001), respectively. Bladder capacity and sensation were not changed during TEA. All patients had a postvoid residual determined by ultrasound of less than 100 ml 1 day after removal of the epidural catheter.


CONCLUSIONS
In contrast to our initial hypothesis, detrusor activity was significantly impaired during TEA after open renal surgery. This resulted in clinically relevant postvoid residuals.
Wuethrich
Patrick Y
PY
Department of Anesthesiology and Pain Therapy, University Hospital Bern, Berne, Switzerland. patrick.wuethrich@insel.ch
Kessler
Thomas M
TM
Panicker
Jalesh N
JN
Curatolo
Michele
M
Burkhard
Fiona C
FC
D000368:Aged; D015360:Analgesia, Epidural / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000209:etiology; D011446:Prospective Studies; D013904:Thoracic Vertebrae; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging*; D014555:Urination Disorders / Q000000981:diagnostic imaging* / Q000209:etiology; D013521:Urologic Surgical Procedures, Male / Q000009:adverse effects*