| Pudendal anesthesia | |
|---|---|
 Approximate area of "saddle anesthesia" seen from behind (yellow highlight) | |
| Other names | Saddle block |
| Specialty | anaesthesiology |
| Pudendal anesthesia | |
|---|---|
| Approximate area of "saddle anesthesia" seen from behind (yellow highlight) | |
| Other names | Saddle block |
| Specialty | anaesthesiology |
Pudendal anesthesia (pudendal nerve block , pudendal block or saddle block) is a form of local anesthesia. Pudendal anesthesia can be used to diagnose as well as treat illnesses. [1] A nerve block is the use of local anesthetic (e.g lidocaine) to inhibit the sensation of pain caused by one or multiple nerves. [2] A nerve block can help doctors confirm what nerve is causing the pain to support a diagnosis. A nerve block can also be used to prevent pain before a procedure, or relieve chronic pain. [2] The pudendal block gets its name because a local anesthetic, such as lidocaine or chloroprocaine, is injected into the pudendal canal where the pudendal nerve is located. The pudendal nerve branches off of the sacral plexus and is both a sensory and motor nerve. [2] The pudendal nerve provides sensation information (i.e. innervates) for the anal canal, external anal sphincter, and the perineum. [3] Pudendal nerve blocks can be used to provide pain relief to this region for about 30 days, but has been reported to last months in some patients. [2] It is primarily used to provide analgesia during obstetrics procedures such as forceps delivery. [4] It can also be used during anorectal surgery, urologic surgery, diagnosing or treating chronic perineal pain (i.e. pudendal neuralgia), and other gynecologic procedures [2] [4]
Overall, the procedure involves injecting a local anesthetic drug (e.g. lidocaine or bupivicaine) with a 20 gauge spinal needle near the pudendal nerve in order to provide pain relief. [1] [2] Lidocaine is usually preferred for a pudendal block because it has a longer duration than chloroprocaine which usually lasts less than one hour. [5] The procedure can be done without imaging guidance, but fluoroscopy or ultrasound can be used. [2] [4] Ultrasound is preferred because there is no exposure to radiation, it is readily available, and it offers real-time guidance for needle insertion. [4] There are different anatomical approaches for which the procedure can be performed such as; transvaginal, transperineal, or perirectal. [1] The aim is to block the nerve as it enters the lesser sciatic foramen, which anatomically is just below the and inwards from the attachment of the sacrospinous ligament to the ischial spine of the pelvic bone. [2] The transvaginal approach is used for obstetric and gynecological procedures. The ischial spines are identified by palpation of the vaginal walls and the needle is advanced through the vaginal wall. [2] The transperineal approach more commonly requires image guidance and is used for anorectal and urologic procedures, and treatment of pudendal neuralgia. For both the transperineal and the perirectal approach the ischial spines are identified through palpation of the rectal walls. [2] The perirectal approach requires the use of a nerve simulator that if placed in the correct position will cause the external anal sphincter to contract. This helps confirm the correct positioning of the needle as it is advanced laterally to the rectum. [2]
A pudendal nerve block has been historically used to provide pain relief during child birth. It is generally used as a second line option, when neuraxial (i.e. epidural) anesthesia is not available or contraindicated. [6] It is normally used during the second stage of labor because it does not relieve the pain from contractions that occur during the first stage. [6] [7] It may also prevent the bearing down reflex during a contraction, therefore it should not be used to early in labor. [8] It can also be used for pain relief from episiotomy or perineal lacerations [6] [8] Pudendal anesthesia is used during operative vaginal delivery which includes the use of forceps. [7] It is best used in addition to epidural anesthesia because the pudendal nerve block alone is not usually sufficient to treat the pain. [7] Pudendal anesthesia is not effective for other forms of vaginal delivery such as rotational deliveries. [7] In regards to safety of the neonate during and after this procedure, there has not been enough investigation. [7] Pudendal nerve blocks are also being studied for their use in minimally invasive gynecological surgery (MIGS). The use of this regional anesthesia may decrease postoperative pain and the need for opioids. [9]
Chronic pain that arises in the rectum, anus, urethra or genitalia is considered chronic perineal pain or pudendal neuralgia. Patients that suffer from chronic perineal pain are most commonly female, affecting 1 in 7 women. [1] The pain may be described as a burning, tingling, stabbing, or electric-shock like sensation and it is usually only affects one side of the body. [2] Pudendal neuralgia can arise from trauma, overuse, sports, surgery, radiation therapy, tumors, viruses (e.g. Herpes Zoster, HIV), endometriosis, multiple sclerosis, pudendal nerve entrapment, or other medical conditions. [1] [2] The most common of these causes in repetitive and overuse injury. [2] Generally, the sensory function of the pudendal nerve is affected more than the motor function. [2] Pudendal nerve blocks can be used in diagnosis as well as treatment of pudendal neuralgia. [1]
The use of the pudendal nerve block is being explored in pediatric urologic procedures such as circumcision. It allows pain relief from the perineum to the end of the penis. [10] It lowers post operative pain and the need for opioids just as it does for MIGS. [9] [10]
A common anorectal surgery that utilizes pudendal anesthesia is a hemorrhoidectomy. A pudendal nerve block provides a longer duration of pain relief versus the use of superficial local anesthetic or even spinal anesthesia. It also may reduce opioid consumption, shorten hospital stay, and have fewer adverse effects like nausea and vomiting. [11]
Common
Uncommon
The perineum in mammals is the space between the anus and the genitals. The human perineum is between the anus and scrotum in the male or between the anus and vulva in the female. The perineum is the region of the body between the pubic symphysis and the coccyx, including the perineal body and surrounding structures. The perineal raphe is visible and pronounced to varying degrees. The perineum is an erogenous zone. This area is also known as the taint or gooch in American slang.
The pudendal nerve is the main nerve of the perineum. It is a mixed nerve and also conveys sympathetic autonomic fibers. It carries sensation from the external genitalia of both sexes and the skin around the anus and perineum, as well as the motor supply to various pelvic muscles, including the male or female external urethral sphincter and the external anal sphincter.
Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, i.e. local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with reduced pain and distress. In many situations, such as cesarean section, it is safer and therefore superior to general anesthesia.
A local anesthetic (LA) is a medication that causes absence of all sensation in a specific body part without loss of consciousness, as opposed to a general anesthetic, which eliminates all sensation in the entire body and causes unconsciousness. Local anesthetics are most commonly used to eliminate pain during or after surgery. When it is used on specific nerve pathways, paralysis also can be induced.
Fecal incontinence (FI), or in some forms, encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents, both liquid stool elements and mucus, or solid feces. When this loss includes flatus (gas), it is referred to as anal incontinence. FI is a sign or a symptom, not a diagnosis. Incontinence can result from different causes and might occur with either constipation or diarrhea. Continence is maintained by several interrelated factors, including the anal sampling mechanism, and incontinence usually results from a deficiency of multiple mechanisms. The most common causes are thought to be immediate or delayed damage from childbirth, complications from prior anorectal surgery, altered bowel habits. An estimated 2.2% of community-dwelling adults are affected. However, reported prevalence figures vary. A prevalence of 8.39% among non-institutionalized U.S adults between 2005 and 2010 has been reported, and among institutionalized elders figures come close to 50%.
Episiotomy, also known as perineotomy, is a surgical incision of the perineum and the posterior vaginal wall generally done by an obstetrician. This is usually performed during the second stage of labor to quickly enlarge the aperture, allowing the baby to pass through. The incision, which can be done from the posterior midline of the vulva straight toward the anus or at an angle to the right or left, is performed under local anesthetic, and is sutured after delivery.
Pudendal nerve entrapment (PNE), also known as Alcock canal syndrome, is an uncommon source of chronic pain in which the pudendal nerve is entrapped or compressed in Alcock's canal. There are several different types of PNE based on the site of entrapment anatomically. Pain is positional and is worsened by sitting. Other symptoms include genital numbness, fecal incontinence and urinary incontinence.
Spinal anaesthesia, also called spinal block, subarachnoid block, intradural block and intrathecal block, is a form of neuraxial regional anaesthesia involving the injection of a local anaesthetic or opioid into the subarachnoid space, generally through a fine needle, usually 9 cm (3.5 in) long. It is a safe and effective form of anesthesia usually performed by anesthesiologists that can be used as an alternative to general anesthesia commonly in surgeries involving the lower extremities and surgeries below the umbilicus. The local anesthetic with or without an opioid injected into the cerebrospinal fluid provides locoregional anaesthesia: true analgesia, motor, sensory and autonomic (sympathetic) blockade. Administering analgesics in the cerebrospinal fluid without a local anaesthetic produces locoregional analgesia: markedly reduced pain sensation, some autonomic blockade, but no sensory or motor block. Locoregional analgesia, due to mainly the absence of motor and sympathetic block may be preferred over locoregional anaesthesia in some postoperative care settings. The tip of the spinal needle has a point or small bevel. Recently, pencil point needles have been made available.
A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depending on whether the prolapsed section is visible externally, and whether the full or only partial thickness of the rectal wall is involved.
Nerve block or regional nerve blockade is any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief. Local anesthetic nerve block is a short-term block, usually lasting hours or days, involving the injection of an anesthetic, a corticosteroid, and other agents onto or near a nerve. Neurolytic block, the deliberate temporary degeneration of nerve fibers through the application of chemicals, heat, or freezing, produces a block that may persist for weeks, months, or indefinitely. Neurectomy, the cutting through or removal of a nerve or a section of a nerve, usually produces a permanent block. Because neurectomy of a sensory nerve is often followed, months later, by the emergence of new, more intense pain, sensory nerve neurectomy is rarely performed.
The perineal nerve is a nerve of the pelvis. It arises from the pudendal nerve in the pudendal canal. It gives superficial branches to the skin, and a deep branch to muscles. It supplies the skin and muscles of the perineum. Its latency is tested with electrodes.
Chloroprocaine is a local anesthetic given by injection during surgical procedures and labor and delivery. Chloroprocaine vasodilates; this is in contrast to cocaine which vasoconstricts. Chloroprocaine is an ester anesthetic.
Anorectal abscess is an abscess adjacent to the anus. Most cases of perianal abscesses are sporadic, though there are certain situations which elevate the risk for developing the disease, such as diabetes mellitus, Crohn's disease, chronic corticosteroid treatment and others. It arises as a complication of paraproctitis. Ischiorectal, inter- and intrasphincteric abscesses have been described.
In humans, the anus is the external opening of the rectum located inside the intergluteal cleft. Two sphincters control the exit of feces from the body during an act of defecation, which is the primary function of the anus. These are the internal anal sphincter and the external anal sphincter, which are circular muscles that normally maintain constriction of the orifice and which relaxes as required by normal physiological functioning. The inner sphincter is involuntary and the outer is voluntary. Above the anus is the perineum, which is also located beneath the vulva or scrotum.
Perineoplasty denotes the plastic surgery procedures used to correct clinical conditions of the vagina and the anus. Among the vagino-anal conditions resolved by perineoplasty are vaginal looseness, vaginal itching, damaged perineum, fecal incontinence, genital warts, dyspareunia, vaginal stenosis, vaginismus, vulvar vestibulitis, and decreased sexual sensation. Depending upon the vagino-anal condition to be treated, there are two variants of the perineoplasty procedure: the first, to tighten the perineal muscles and the vagina; the second, to loosen the perineal muscles.
Obstructed defecation syndrome is a major cause of functional constipation, of which it is considered a subtype. It is characterized by difficult and/or incomplete emptying of the rectum with or without an actual reduction in the number of bowel movements per week. Normal definitions of functional constipation include infrequent bowel movements and hard stools. In contrast, ODS may occur with frequent bowel movements and even with soft stools, and the colonic transit time may be normal, but delayed in the rectum and sigmoid colon.
Obstetric anesthesia or obstetric anesthesiology, also known as ob-gyn anesthesia or ob-gyn anesthesiology, is a sub-specialty of anesthesiology that provides peripartum pain relief (analgesia) for labor and anesthesia for cesarean deliveries ('C-sections').
Pain management during childbirth is the treatment or prevention of pain that a woman may experience during labor and delivery. The amount of pain a woman feels during labor depends partly on the size and position of her baby, the size of her pelvis, her emotions, the strength of the contractions, and her outlook. Tension increases pain during labor. Virtually all women worry about how they will cope with the pain of labor and delivery. Childbirth is different for each woman and predicting the amount of pain experienced during birth and delivery can not be certain.
The vaginal support structures are those muscles, bones, ligaments, tendons, membranes and fascia, of the pelvic floor that maintain the position of the vagina within the pelvic cavity and allow the normal functioning of the vagina and other reproductive structures in the female. Defects or injuries to these support structures in the pelvic floor leads to pelvic organ prolapse. Anatomical and congenital variations of vaginal support structures can predispose a woman to further dysfunction and prolapse later in life. The urethra is part of the anterior wall of the vagina and damage to the support structures there can lead to incontinence and urinary retention.
Deep gluteal syndrome describes the non-discogenic extrapelvic entrapment of the sciatic nerve in the deep gluteal space. It is an extension of non-discogenic sciatic nerve entrapment beyond the traditional model of piriformis syndrome. Symptoms are pain or dysthesias the buttocks, hip, and posterior thigh with or without radiating leg pain. Patients often report pain when sitting. The two most common causes are piriformis syndrome and fibrovascular bands, but many other causes exist. Diagnosis is usually done through physical examination, magnetic resonance imaging, magnetic resonance neurography, and diagnostic nerve blocks. Surgical treatment is an endoscopic sciatic nerve decompression.
