Errors of Rectal Pressure Measurement in Urodynamic Study of Spinal Cord Injured Patients

OBJECTIVE: The intrarectal pressure can make error during urodynamic study and can decrease the accuracy of detrusor pressures. The purpose of this study was to investigate the incidence and cause of the error in measurement of recral pressure. METHOD: Forty-eight patients with spinal cord injury were enrolled. With the patients in the lithotomy position, catheter was placed into the bladder and the rectum, then urodynamic testing began by infusion of normal saline (20~30degrees C) via urethral catheter. The errors by measurement of rectal pressure during urodynamic study were recorded. According to the position of patients and spasticity of hip flexors, difference of rectal pressure was investigated. RESULTS: The error rate of intrarectal pressure during urodynamic study was 41%. Intrarectal pressure was higher in lithotomy position than in lateral lying position. According to modified Ashworth scale of hip flexors, intrarectal pressure in grade 0 was significantly lower than grade 1, 1.5 and 2 (p<0.05). CONCLUSION: There was significant errors in measuring of the intravesical pressure during urodynamic study. These factors might be posture, spasticity of hip flexors, and expelling of the catheter in urodynamic study.

Change of Intra-abdominal Pressure on Daily Activities in Patients with Spinal Cord Injury

PURPOSE: To evaluate the change of intra-abdominal pressure related with intravesical and intrarectal pressure in patients with spinal cord injury according to daily activities and postural changes which make the abdominal pressure elevated. MATERIALS AND METHODS: Ten subjects with lower thoracic and lumbar spinal cord injury were enrolled. Their mean age was 38 years. The urodynamic study was performed and the intravesical and the intrarectal pressures were measured with a double lumen catheter and a intrarectal probe. The intravesical and the intrarectal pressure were obtained during patient's speech, sneeze, cough, valsalva and various postural changes with supine to decuitus, decubitus to supine, supine to sit, and sit to supine according to empty and full bladders, respectively. RESULTS: The order of higher intravesical and intrarectal pressure rise during various maneuvers were valsalva, sneeze, supine to sit and cough, respectively. Higher correlation coefficient between the intravesical and intrarectal pressures were noted during cough, sneeze, valsalva and supine to sit in empty bladder than full one. CONCLUSION: These results demonstrated that the intravesical and intrarectal pressures were influenced by daily activities and postural changes of increasing the intra-abdominal pressure. The intrarectal pressures according to daily activities such as cough, sneeze, valsalva and postural change were significantly related with intravesical pressures.

Usefulness of the Portable Cystometer

OBJECTIVE: To evaluate the usefulness of a newly devised portable cystometer to measure the pressure of bladder in a low cost and easier accessability. METHOD: This study was performed in 47 patients with a conventional instrumental cystometer (Jupiter 8000, Wiest) and the newly devised portable cystometer. In the supine position, we measured the maximal intravesical pressure, abdominal pressure and bladder volume with the portable cystometer just after the measurement of the maximal detrusor pressure and bladder volume with the conventional instrumental cystometer. Paired t-test was utilized to analyze and compare the result. RESULTS: 1) There was no significant difference in the average maximal detrusor pressures measured by maximal intravesical pressures minus abdominal pressures, which were 38.32 20.97 cmH2O by the conventional instrumental cystometer and 40.02 20.70 cmH2O by the portable cystometer (p>0.05). 2) There was no significant difference in the average bladder volumes at maximal detrusor pressure, which were 302.13 83.92 cc by the conventional instrumental cystometer and 314.04 94.17 cc by the portable cystometer (p>0.05). CONCLUSION: We conclude that there is no significant difference between the conventional instrumental cystometer and the portable cystometer in the measurement of detrusor pressure and bladder volume. We believe this portable cystometer would be a useful tool to evaluate the function of bladder in a low cost and easier accessability.

Comparison between Conventional Cystometry and Diuretics Stimulated Filling Cystometry in Neurogenic Bladder after Spinal Cord Injury

OBJECTIVE: To determine whether cystometry performed by bladder filling stimulation using furosemide (DCMG) reveals different findings compared to conventional cystometry (CCMG) in the neurogenic bladder. METHOD: The maximum intravesical pressure (MPves) and compliance of the bladder in CCMG and DCMG were compared in 24 patients with neurogenic bladder after spinal cord injury. The MPves was estimated by urethral leak pressure or intravesical pressure at 600 ml filling. Compliance was calculated from the cystometric bladder capacity and the MPves. For CCMG, the bladder was filled with 32oC normal saline via 10 F urethral catheter at 50 ml/min until the patient leaked or filled 600 ml. Three hours later, 20 mg of furosemide was injected intravenously after intravenous infusion of 300 ml normal saline for DCMG. Ultrasound measuring of filled urine volume was made at least every 5 minutes until defined MPves. RESULTS: Significant differences were found between DCMG and CCMG in hyperreflexic neurogenic bladders with respect to: decrease in MPves (p0.05). CONCLUSION: We have found DCMG provides a more effective and near physiological diagnostic method of detrusor characteristics than CCMG in evaluating both genuine MPves and compliance in patients with hyperreflexic neurogenic bladder.