Neurogenic Bowel Flashcards
SCI
GI Involvement in SCI
- Oral Hygiene
- Dysphagia (steophytes discs or cervical fixation hardware)
- Gastric Ulcers (first weeks after injury)
- Gallstones ter SCI can reach 30%, yet in spite of this high prevalence, acute cholecystitis does not occur with greater frequency or at increased risk for mortality
. Superior mesenteric artery syndrome produces gastric distention, bloating, and vomiting that results from the superior mesenteric artery descending and pinching off the distal duodenum; this is termed the nutcracker effect. - Nomtrau pancreatitis occurs infrequently after acute SCI, likely because of sphincter of Oddi spasm, thickening of pancreatic secretions, and vagal dominant innervation
- Surveillance with stool guaiacs, serum amylase, and calcium levels during the first month after SCI can lead to early identification of complications
Function of Colon
The most clinically useful index of overall colonic function is colonic transit time, the amount of time required for contents to pass from the cecum to the outside.
Internal Sphincter
The internal anal sphincter (IAS) is the specialized thickening of the circular smooth muscle layer of the rectum that maintains a continuous state of maximal contraction. It is responsible for the majority of resting tone in the anal canal. Normal internal anal canal resting pressures range from 50 to 100 cm H2O. This resting tone is not altered after SCI
External Sphincter
The external anal sphincter (EAS) is a striated muscle that is continuous with the pelvic floor and is innervated by the pudendal nerves bilaterally. The EAS, along with muscles of the pelvic floor, displays the unusual property of continuous electrical activity in both the waking and sleeping states
Puborectalis
The puborectalis muscle originates from behind the pubic symphysis and extends posteriorly to loop around the rectum just proximal to the anal canal. The puborectalis tugs the rectum anteriorly and creates an angle between the rectum and anal canal, the anorectal angle. This kink in the fecal pathway aids in continence. Conversely, failure of the puborectalis to relax appropriately, with persistence of an acute anorectal angle, has been associated with inability to defecate
Anal Sphincter Mechanism
The IAS, the EAS, and the puborectalis work together synergistically to maintain continence and are collectively named the anal sphincter mechanism.
How it works?
The mucosa at the proximal end of the rectum and anal canal is rich in sensory receptors. This allows for socially critical judgments about the phases of the matter therein: liquid, solid, and gaseous material.
The rectoanal inhibitory or sampling reflex allows a sample of the rectal contents to come into contact with this sensory zone. The rectoanal inhibitory reflex consists of a transient relaxation of the IAS stimulated by a rise in rectal pressure.
A simultaneous increase in EAS tone, the guarding reflex, occurs to preserve continence while sensory receptors of the rectum appraise the contents. The rectoanal inhibitory reflex occurs during sleep and throughout the day, usually at a subconscious level.
Suprasacral
Supraspinal bowel dysfunction occurs with lesions rostral to the pons. Voluntary defecation depends on an accurate perception of need to defecate as well as the necessary motor function to position over a toilet and to initiate the complex motor activity of bowel evacuation. A failure to perceive rectal fullness is common in the elderly and may manifest as overflow incontinence around a fecal impaction
LMN
Patients with lower motor neuron bowel typically have SCI lesions affecting the conus or cauda equina. Anal canal tone is reduced, anocutaneous bulbocavernosus reflexes are absent, and the pelvic floor may passively descend. Bowel care for lower motor neuron SCI typically consists of digital rectal stimulation and manual evacuation after the morning and evening meals. A study of bowel-care patterns of persons with SCI revealed that the average frequency of bowel care in persons with lower motor neuron bowel was twice per day
UMN
Overall bowel management is outlined in the bowel program, which includes the following components: diet, fluid intake, medications, physical activity, and a schedule for bowel care. Bowel care is the procedure for assisted defecation with one or more of the following components: positioning, assistive devices, rectal simulation or trigger for defecation, and assistive maneuvers (abdominal massage)
ACE
An anterograde continence enema procedure may be an option for adult patients with neurogenic bowel recalcitrant to a bowel program. Originally designed for children with myelomeningocele, it also significantly decreases toileting time and improves quality of life. Patients also find it more cosmetically acceptable than a colostomy.
Surgery
Surgical treatments should be considered if diet modifications, medications, and physical techniques have been attempted but fail to produce a consistent bowel movement. Colostomies and ileostomies decrease the time required for bowel management, increase independence, and simplify the overall process. Many patients have reported that they retrospectively wished that these alternatives were offered earlier
Assistive Techniques
Assistive techniques such as Valsalva maneuver, abdominal massage in a clockwise direction, increase in physical activity, standing, and completing the bowel program in a commode chair rather than in bed can also greatly facilitate the process.
Components of Bowel Manaement
components: diet, fluid intake, medications, physical activity, and a schedule for bowel care. Bowel care is the procedure for assisted defecation with one or more of the following components: positioning, assistive devices, rectal simulation or trigger for defecation, and assistive maneuvers (abdominal massage) Assistive techniques such as Valsalva maneuver, abdominal massage in a clockwise direction, increase in physical activity, standing, and completing the bowel program in a commode chair rather than in bed can also greatly facilitate the process.
