Pudendal Blockade Research Articles

The Impact of Pudendal Nerve Injection in Vaginal Surgery: A Secondary Analysis

Importance Evidence regarding the effect of pudendal nerve blockade during vaginal surgery is conflicting. Previous studies compared pudendal nerve blockade to either normal saline placebo injection or no injection, demonstrating small or no difference in pain outcomes. Studies investigating nerve blocks at the time of vaginal surgery have not evaluated the effect of infiltration of the space around the pudendal nerve. Objective The aim of the study was to determine whether intraoperative pudendal nerve injection (bupivacaine or normal saline) will result in improved pain scores and satisfaction compared with patients who receive no pudendal injection. Study Design We performed a secondary analysis of 2 randomized controlled trials investigating postoperative pain after vaginal reconstructive surgery, comparing the outcomes of the following 3 groups: control (no pudendal injection), intervention (bilateral pudendal nerve blockade), and placebo (bilateral normal saline pudendal injections). The primary outcome was postoperative pain scores. Secondary outcomes were opioid use, patient satisfaction, and postoperative complications. Linear mixed effects models were applied to outcomes, and treatment effects with 95% confidence intervals were estimated at each time point from the model. Results One hundred four patients who underwent vaginal surgery were included: 36 pudendal nerve block, 35 normal saline pudendal injection, and 33 no injection. The groups were well-matched. Linear mixed effects models demonstrated no significant differences between treatment groups for postoperative pain severity scores, opioid use, and patient-reported satisfaction at each time point. Conclusions Normal saline injection and no injection seem to have no clinically meaningful difference in effect, and either could reasonably serve as control for pudendal blockade during vaginal surgery.

Effect of Pudendal Blockade on Bladder Emptying After Midurethral Sling: A Randomized Controlled Trial.

To evaluate the effect of bilateral pudendal nerve blockade on immediate postoperative bladder emptying after midurethral sling. We performed a double-blinded, randomized, placebo-controlled trial of women undergoing a midurethral sling procedure between October 2017 and February of 2019. Women older than 18 years were eligible if they were undergoing a midurethral sling with no concomitant procedures and had no preoperative urinary retention. Participant demographics and medical conditions that may affect bladder emptying were recorded preoperatively. Participants were randomized to a bilateral pudendal injection of either bupivacaine or normal saline. After induction of anesthesia, the pudendal injection was administered before any incisions. No other local anesthesia was used. The primary outcome was the rate of passing a standardized void trial. Secondary outcomes included perioperative pain scores, analgesia use, and complications. Ninety-one participants were enrolled in the study. One patient had a delayed void trial on postoperative day 1, leaving 90 participants for the final analysis. Demographic and perioperative characteristics were similar between the groups. Adjusted logistic regression showed that the administration of a bupivacaine pudendal block led to a higher rate of void trial failure (43% vs 20%, odds ratio = 0.32, P = 0.02 adjusted for age, body mass index, and comorbidities). Postoperative pain scores and analgesia use were similar between the groups. Postoperative complications, including urinary tract infection, mesh erosion, pelvic hematoma, or urinary retention within 6 weeks were similar between the groups. Our prospective trial demonstrates that a bilateral pudendal blockade before midurethral sling procedure worsens postoperative bladder emptying.

71: Effect of pudendal blockade on bladder emptying after midurethral sling: A randomized controlled trial

To evaluate the effect of bilateral pudendal nerve blockade on immediate postoperative bladder emptying following midurethral sling. We performed a double-blinded, randomized, placebo-controlled trial of women undergoing a midurethral sling procedure between October 2017 and February of 2019. Women > age of 18 were eligible if they were undergoing a midurethral sling with no concomitant procedures and had no preoperative urinary retention. Subject demographics and medical conditions that may impact bladder emptying were recorded pre-operatively. Participants were randomized to a bilateral pudendal block of either 20 cc of 0.25% bupivacaine or 20 cc of normal saline. Randomization was performed using a 1:1 ratio and a block randomization scheme. The study medications were prepared in standard 10 cc syringes with blinding of both the participant and surgeon maintained throughout the study. After induction of anesthesia, a pudendal block was administered by a urogynecology attending or fellow prior to any incisions. No other local anesthesia was used. The primary outcome was the rate of passing a standardized void trial. Secondary outcomes included perioperative pain scores, analgesia use and complications. Ninety-one subjects were enrolled in the study. One patient had a delayed void trial on postoperative day one, leaving 90 subjects for the final analysis. Demographic and perioperative characteristics were similar between the groups. Adjusted logistic regression showed the administration of bupivacaine pudendal block worsened postoperative bladder emptying (OR=0.32, p=0.02 adjusted for age, BMI, and comorbidities). Postoperative pain scores and analgesia use were similar between the groups. Postoperative complications including UTI, mesh exposure, pelvic hematoma or urinary retention within 6 weeks were similar between the groups. Our prospective trial demonstrates that a bilateral pudendal blockade prior to midurethral sling procedure worsens postoperative bladder emptying.

Postoperative analgesia for hemorrhoidectomy with bilateral pudendal blockade on an ambulatory patient: a controlled clinical study

BACKGROUND AND OBJECTIVES: Reducing postoperative pain in hemorrhoidectomy is still a challenge. This prospective, randomized, double-blind study was conducted to compare bilateral pudendal blockade with peripheral nerve stimulator to relieve postoperative pain with the method commonly used. METHOD: 200 patients scheduled for hemorrhoidectomy were randomly divided into Control Group and Pudendal Group. Bilateral pudendal block was performed with levobupivacaine enantiomeric excess (S75:R25) after location with a peripheral nerve stimulator. The parameters evaluated were pain intensity, duration of analgesia, rescue analgesia, complications, patient satisfaction and pain at first defecation. Data were recorded at 6, 12, 18 and 24 hours after the surgery. RESULTS: Bilateral pudendal nerves with mean 23.4±4.4 hours provided better relief of postoperative pain (p<0.001), reducing the need for analgesics and residual analgesia for more than 24 hours in 41% of patients. All patients in Pudental Group had spontaneous micturition versus 96 in the control group. There was no local or systemic complications. CONCLUSIONS: Bilateral blockade of the pudendal nerve using a neurostimulator provided better pain relief with less need for rescue dose and no local or systemic complications.

Functional Analysis of Active Urethral Closure Mechanisms Under Sneeze Induced Stress Condition in a Rat Model of Birth Trauma

We evaluated changes in the urethral closure mechanism under a sneeze induced stress condition in a rat model of birth trauma. Four days after vaginal distention induced by balloon catheter inflation in the vagina sneezing was induced while recording intravesical pressure with the rat under urethane anesthesia to evaluate sneeze induced leak point pressure, defined as the lowest pressure inducing fluid leakage from the urethral meatus during sneezing. Sneeze induced responses in the bladder and proximal or mid urethra were also measured using microtip transducer catheters. In 5 sham operated rats no leakage was observed from the urethral meatus during sneezing, which produced an increase in intravesical pressure of up to 34 cm H(2)O. However, in 5 of 6 rats with vaginal distention leakage during sneezing was observed with a sneeze leak point pressure of 26.2 cm H(2)O. In the mid urethra microtip transducer catheters revealed that pressure increases during sneezing were greater than those in the bladder but they were significantly decreased in the 5 incontinent vaginal distention rats. However, sneeze induced responses at the proximal urethra, which were similar to those in the bladder, were not different in sham operated and incontinent vaginal distention rats. Sneeze induced stress urinary incontinence in a rat model of birth trauma was caused by decreased active closure mechanisms at the mid urethra without affecting the passive transmission of abdominal pressure in the proximal urethra.

Innervation of the Pelvic Floor Muscles

We investigated the clinical anatomy of the levator ani nerve and its topographical relationship with the pudendal nerve. Ten female pelves were dissected and a pudendal nerve blockade was simulated. The course of the levator ani nerve and pudendal nerve was described quantitatively. The anatomical data were verified using (immuno-)histochemically stained sections of human fetal pelves. The levator ani nerve approaches the pelvic-floor muscles on their visceral side. Near the ischial spine, the levator ani nerve and the pudendal nerve lie above and below the levator ani muscle, respectively, at a distance of approximately 6 mm from each other. The median distance between the levator ani nerve and the point of entry of the pudendal blockade needle into the levator ani muscle was only 5 mm. The levator ani nerve and the pudendal nerve are so close at the level of the ischial spine that a transvaginal "pudendal nerve blockade" would, in all probability, block both nerves simultaneously. The clinical anatomy of the levator ani nerve is such that it is prone to damage during complicated vaginal childbirth and surgical interventions.

The Urethral Resistance to Rapid Dilatation: An Analysis of the Effect of Autonomic Receptor Stimulation and Blockade and of Pudendal Nerve Blockade in Healthy Females

The urethral closure function is based upon permanently as well as adjunctively acting closure forces during rest and stress episodes, respectively. During urine ingression intra- and peri-urethral structures are suddenly stretched resulting in a pressure response which strengthens the closure function by sustaining the resistance to dilatation of the urethra. A method for measurement of the resistance to rapid urethral dilatation was used to evaluate the influence of noradrenaline, prazosin, terbutaline, propranolol, carbachol, and atropine, as well as bilateral pudendal nerve blockades in 40 healthy women. The drugs caused no significant change in the urethral resistance to dilatation, whereas the pudendal blockade produced a significant (p < 0.05) reduction at the bladder neck and in the high pressure zone. Although a quantitative assessment of their contribution cannot be obtained from this study, it may be concluded that the striated muscles innervated by the pudendal nerve are of major importance for the urethral resistance to dilatation.

The Effect of Bilateral Pudendal Blockade on the Adjunctive Urethral Closure Forces in Healthy Females

The effect of bilateral pudendal blockade on the urethral pressure and power generation during coughing and pelvic floor squeezing was evaluated in 10 healthy women. The measurements were carried out at the bladder neck, in the high pressure zone, and distally in the urethra before and after blockade. Strong adjunctive closure forces were demonstrated all along the urethra. They were significantly reduced by pudendal blockade except at the bladder neck during coughing. The results indicate that the pudendal innervated striated muscles contribute significantly to the adjunctively acting closure forces all along the female urethra, including the bladder neck. Some passive pressure transmission to the bladder neck seems to take place during stress episodes following pudendal blockade, but whether it occurs in healthy females remain uncertain. The findings following pudendal blockade, corroborate with those in stress incontinent women, and thereby support the concept that striated muscle weakness is of pathophysiological significance in stress urinary incontinence.

The effect of pharmacological stimulation and blockade of autonomic receptors and of pudendal blockade on urethral stress relaxation in healthy women.

To examine the influence of autonomic receptor stimulation and blockade (noradrenaline, prazosin, terbutaline, propranolol, carbachol and atropine), and of pudendal nerve blockade on urethral stress relaxation. Forty healthy women were evaluated. The stress relaxation parameter was defined as the relative rate of pressure decrease during a fixed period of time following a rapid dilatation of the urethra. The dilatation was performed by water-infusion into a small rubber cylinder placed in the urethra. The drugs did not affect stress relaxation significantly, whereas the pudendal blockade produced a significant change along the length of the urethra characterized by a faster pressure decay following dilatation. In women, stress relaxation in the urethra relies significantly on the pudendal nerve-innervated striated muscles.

CONTINUOUS MINI‐INFUSION OF BUPIVACAINE INTO THE EPIDURAL SPACE DURING LABOR

Obstetric analgesia was accomplished by segmental continuous blockade in 225 women. The technique involved automatic pump infusion of 0.25 per cent bupivacaine solution into the epidural space at a rate of 5 ml per hour after initial doses of 2 and 5 ml bupivacaine. If the analgesia was insufficient one or two single injections of 5 ml of bupivacaine were added. Statistical evaluation of the results could be carried out for 218 women, 158 of whom were nulliparae and 60 multiparae. Fully satisfactory analgesia was achieved in 96 per cent of the nulliparae and 88 per cent of the multiparae in the first stage of labor. In the second stage of labor 46 per cent of the mothers were given pudendal blockade to maintain statisfactory analgesia. The positioning of the patient in the first stage of labor from supine to semirecumbent was of importance to spread the analgesic agent caudally, to the sacral nerve roots, and to control the pain due to stretching of the vagina and perineum. In the total material 17 per cent of the neonates were delivered by vacuum extraction. When the infusion into the epidural space was started in early labor, the incidence of vacuum extraction was 9 per cent, as compared with 38 per cent when it was started at 6 cm cervical dilatation or later (p less than 0.01). 9.8 per cent of the neonates were delivered by cesarean section. Fetal head malposition occurred in 8.7 per cent. A drop in blood pressure was noted in 7 per cent of the women. The condition of the newborn was unaffected by the analgesia. The mini-infusion system minimized the risk for infection. The danger in case of accidental intravascular injection was reduced, due to slowly administered bupivacaine. At the maternity department this technique has created a positive attitude towards epidural blockade, as midwives and doctors have found it safe and easy.