Abdomen and pelvis
Ischial tuberosity
The sitting bone: the rough knob at the bottom of each ischium, in the lower buttock, that takes the body's weight in a chair.
Why the exam cares
Which bony point breaks down depends on position: upright sitting loads the ischial tuberosities, lying flat loads the sacrum and heels, and slumping or semi-reclining adds shear over the sacrum and coccyx. A wheelchair user with no sensation below the waist cannot feel the warning, so the nurse matches prevention to the position the patient spends the day in.
- Sit on the hands: the two hard knobs pressing into the palms are the ischial tuberosities.
- They lie deep to the lower buttock near the gluteal fold, the crease between buttock and thigh.
- Standing, the gluteus maximus covers them. When the hip flexes to sit, the muscle slides off, leaving only skin and fat over the bone.
- The sciatic nerve runs down the back of the thigh lateral to the tuberosity, about midway toward the greater trochanter.
In a chair the tuberosities carry most of the body's weight over a small area of skin. The nurse teaches a wheelchair user to shift weight about every 15 to 30 minutes by leaning side to side, leaning forward, or pushing up on the armrests, and to sit on a pressure-redistributing foam, gel, or air cushion, never a donut or ring cushion, which concentrates pressure around the rim. A patient who cannot shift their own weight is repositioned or returned to bed after about an hour in the chair.
After time in a chair, the nurse, or the patient using a long-handled mirror, inspects the skin over both tuberosities and presses on any red area. Redness that blanches and fades after pressure is relieved is expected; redness that does not blanch is a stage 1 pressure injury, and the cushion, the sitting schedule, or both must change. On darkly pigmented skin, the nurse compares the area with nearby skin for a darker color, a change in warmth, firmness, bogginess, or pain.
Basic Care and ComfortReduction of Risk Potential
Abdomen and pelvisHigh yield
Ischium, pubis, and pelvic outlet
The lower and front bones of the pelvic ring: the ischium you sit on, the two pubic bones joined in front at the symphysis pubis, and the bony opening they help frame at the bottom, the pelvic outlet.
Why the exam cares
In labor, these bones are the ruler: station is counted from the ischial spines, fundal height is measured from the symphysis pubis, and suprapubic pressure is applied just above it. Outside labor, the nurse protects the skin over the sitting bones and, after a pelvic fracture, holds the catheter when there are signs of urethral injury.
- Symphysis pubis: the firm midline ridge at the very bottom of the abdomen, just above the genitals; fundal height is taped from its top edge.
- Ischial tuberosities: the sitting bones, felt as hard knobs deep in each buttock when the hip is flexed; body weight rests on them in a chair.
- Ischial spines: not felt from the outside; the examiner reaches them on the side walls of the pelvis during a vaginal exam.
- Pelvic outlet: the opening framed by the pubic arch in front, the ischial tuberosities at the sides, and the coccyx behind; the last bony passage for the baby.
When the baby's shoulder catches behind the symphysis pubis, the nurse calls for help, flexes the mother's thighs back toward her abdomen, and applies firm pressure just above the symphysis as the provider directs. Never push on the fundus, because that wedges the shoulder tighter against the pubic bone and raises the risk of injury to the baby.
Station is how many centimeters the presenting part sits above (minus) or below (plus) the ischial spines, and station 0 is taught as engaged. After any rupture of membranes the nurse checks fetal heart tones right away. The risk of cord prolapse is highest while station is still negative, because the cord can slip past a part that has not filled the pelvis.
In a chair the body's weight rests on two small bony points, so the skin over the ischial tuberosities breaks down quickly. The nurse teaches a patient who can move to shift weight every 15 minutes, and repositions a chair-bound patient who cannot shift alone at least every hour and limits their chair time. The nurse inspects the skin over the sitting bones when the patient returns to bed.
A pelvic fracture can tear the urethra and can bleed heavily. Blood at the urethral meatus, bruising of the perineum or scrotum, or inability to void means the nurse does not insert a urinary catheter and notifies the provider so the urethra can be checked first. The nurse also watches for falling blood pressure and a rising pulse, because a large amount of blood can collect inside the pelvis unseen.
Health Promotion and MaintenancePhysiological AdaptationBasic Care and Comfort
Abdomen and pelvisHigh yield
Pelvis: ilium and iliac crest
The broad wing of the hip bone; its top ridge is the iliac crest felt at the waist, and its front tip is the anterior superior iliac spine (ASIS).
Why the exam cares
The crest and ASIS are two of the three fingers-on-bone landmarks the NCLEX expects the nurse to name for the ventrogluteal injection, the safest large IM site because no major nerve or vessel runs under it. The back of the crest is where marrow is taken for biopsy, and a line across the tops of both crests marks the level for lumbar puncture, so both procedures' nursing care hangs on this bone.
- The iliac crest is the ridge the hands rest on when placed on the hips; follow it forward to the ASIS.
- The ASIS is the bony bump at the front of the hip, at the top of the groin crease.
- The posterior superior iliac spine sits under the dimple on the low back and is the marrow biopsy site.
- A line across the tops of both crests crosses the spine at about L4, the lumbar puncture landmark.
With the patient side-lying, supine, or prone, the nurse places the heel of the opposite hand on the greater trochanter, points the index finger to the ASIS, and spreads the middle finger back along the iliac crest. The injection goes into the center of the V between the two fingers. This is the preferred IM site for adults and for children over about 7 months, for volumes up to about 3 mL, because the sciatic nerve and large vessels lie well away from it.
The nurse positions the patient prone or side-lying, explains the deep pressure and brief sharp pull as the sample is drawn, and afterward holds firm pressure and applies a pressure dressing. The patient lies on the site for about 30 to 60 minutes while the nurse checks the dressing for bleeding and asks about pain. Because the biopsy is often done for a blood disorder, platelets may be low, and a site that keeps oozing is a bleed the nurse reports rather than re-dresses.
The line between the tops of both iliac crests crosses about the L4 spine, so the provider enters at L3-L4 or L4-L5, below where the spinal cord ends at about L1-L2. The nurse's job is to position the patient side-lying with knees drawn to the chest and chin tucked, which opens those interspaces, and to hold that position so the needle stays at the marked level.
Pharmacological and Parenteral TherapiesReduction of Risk Potential
Abdomen and pelvisHigh yield
Pelvis: pelvic ring fracture
A break in the bony ring at the base of the trunk, formed by the two hip bones joined to the sacrum behind and to each other at the pubic symphysis in front, which surrounds the bladder, rectum, and large iliac vessels.
Why the exam cares
A broken pelvis can bleed liters into a space the nurse cannot see, and the fragments can tear the bladder or, in a male patient, the urethra. The exam question is about spotting hidden shock early and about not inserting a urinary catheter until the urethra has been cleared.
- The iliac crests, at about the L4 level near the waist, form the top of the ring, and the pubic symphysis is the midline joint felt low in front; because it is a ring, a break in front at the pubic rami or symphysis usually pairs with a second break or joint disruption behind at the sacrum or sacroiliac joints.
- The greater trochanters, the bony knobs at the sides of the upper thighs, are where a pelvic binder or folded sheet is centered; a wrap placed up at the iliac crests does not close the ring.
- In a male patient the posterior urethra, where the membranous part meets the bulbar part, sits just below the pubic arch, so a fracture at the front of the pelvis can tear it; the short female urethra is rarely injured.
The nurse watches for a rising heart rate, narrowing pulse pressure, falling blood pressure, cool pale skin, and spreading flank, perineal, or scrotal bruising, starts two large-bore IVs, and applies a pelvic binder or folded sheet centered at the greater trochanters as ordered to close the ring and slow the bleeding. The nurse does not rock or press on the pelvis to check it and moves the patient as little as possible, because movement can dislodge clot and restart bleeding.
Blood at the urethral meatus, blood in the urine, inability to void, or perineal or scrotal bruising mean the urethra or bladder may be torn. The nurse does not insert a urinary catheter and reports the finding, because a catheter can turn a partial urethral tear into a complete one; the provider rules out urethral injury first, usually with a retrograde urethrogram.
The nurse checks pedal pulses, color, sensation, and movement in both feet and compares side to side, because the lumbosacral nerves and the iliac vessels to the legs pass through the pelvis and can be torn or compressed by the fracture. A new deficit is reported right away.
Physiological AdaptationReduction of Risk Potential
Abdomen and pelvisHigh yield
Pubic symphysis
The joint at the front of the pelvis where the two pubic bones meet in the midline, joined by a pad of fibrocartilage that loosens in pregnancy.
Why the exam cares
Its top edge is the nurse's zero point for the lower belly, and the front shoulder of a baby can jam behind it. In a shoulder dystocia the nurse presses just above it and never on the fundus; after pelvic trauma, blood at the urethral opening means no urinary catheter until the provider clears the urethra.
- Press down in the midline just above the genitals until the fingers meet firm bone; that is the top of the symphysis.
- Fundal height is measured from its top edge; the fundus rises just above it at about 12 weeks.
- A full bladder rises above it as a smooth, rounded midline swelling. After birth it pushes the fundus up and to the right: a boggy fundus is massaged first, then the bladder is emptied (see Uterus).
- A suprapubic catheter leaves the skin in the midline a short distance above it.
When the baby's head delivers and pulls back tight against the perineum, the front shoulder is stuck behind the symphysis. The nurse calls for help, notes the time, helps pull the mother's thighs back toward her belly (McRoberts), and gives firm pressure with the heel of the hand just above the symphysis as the provider directs. The nurse never pushes on the fundus, because that drives the shoulder harder against the bone.
After a crash or fall, pelvic pain, perineal bruising, or blood at the urethral opening can mean a broken pelvic ring, which can bleed heavily inside the pelvis. The nurse keeps the patient still, does not rock the pelvis to test it, and watches for shock: a climbing heart rate and falling blood pressure. With blood at the meatus the nurse does not insert a urinary catheter and reports it, because a catheter can worsen a torn urethra.
This catheter enters the bladder through the lower abdominal wall above the symphysis when the urethra cannot be used. The nurse keeps the site clean and dry, secures the tube so it cannot pull, and checks that urine drains and the skin around it is intact. If a newly placed tube comes out, the nurse covers the site and notifies the provider at once instead of reinserting it, because a fresh tract can close quickly and leave the bladder no way to empty.
Physiological AdaptationReduction of Risk PotentialHealth Promotion and Maintenance
