Vomiting in Children (Mueller, 4/21/2021)

Many thanks to Dr. Claudia Mueller, Stanford and CPMC pediatric surgeon, for an excellent presentation on Vomiting in Children-- her lens, unsurprisingly, was on the surgical causes of vomiting in children. 

As a family medicine physician, I don't typically consider vomiting in children a "surgical" problem, but it was sure a good reminder that sometimes it is! It's a hearty crew of clinicians who want to assemble at 7:30am to talk about vomit-- but hey-I have to tell you-- her presentation was excellent!  AND the best part was that Dr. Mueller gave us a number to call if we ever run into problems. 

To watch Dr. Mueller's excellent presentation click HERE.

For the Cliff's notes version, here you go:

• Surgical causes of vomiting in children can rapidly progress to be life threatening
• Ask yourself How sick is this kid? Do they have fever, tachycardia, moist music membranes, lethargy? Can I get them to stand for the KUB?
• Presence of vomiting and ABSENCE of diarrhea is a concerning sign 
• This makes sense; most vomiting in kids is related to acute viral gastroenteritis or food poisoning, both of which should be accompanied by diarrhea. The absence of diarrhea is a sign that surgical causes of vomiting should be on your ddx
• The color of the vomit is key: color gives you some indication of the level the vomit is coming from (I know, I know, who wants to talk about the color of vomit) 
• this is particularly true in infants
• yellow/green (bilious) emesis in children <1 year is an "alarm bell that should be rung through the streets of any city" as it could be a surgical emergency (cardinal hallmark of a midgut volvulus that you do NOT want to miss)
• most children will vomit food and other particulate matter, if they vomit long enough, they will eventually vomit bile, so prolonged vomiting leading to bilious vomiting may be less concerning than it starting out bilious

• The intestine is a tube: in addition to the color of the vomit, what is coming out the bottom gives us a lot of information. If a child is having something out the bottom, they are much less likely to have true obstruction
• Passing gas is best indication (more even than bowel movements)

SBO

• Previous abdominal surgery is #1 cause of of adhesions causing SBO in children
• traumatic surgeries (e.g. trauma ex-lap) are more likely to lead to adhesions
• laparoscopic surgery maybe less risky (eg. laparoscopic appy) 
• Farting is a good sign-- air doesn't just hang out in the colon; a child that is passing gas, even if there is an obstruction, it is at least partial
• Be aware: not all kids with SBO get abdominal distention
• An UPRIGHT KUB is the imaging modality of choice to evaluate for SBO in a child
• want to be able to visualize: diaphragm, rectal gas
• UPRIGHT is super important: air goes to top, liquid down to the bottom
• air-fluid levels (straight lines) in SBO (can see in ileus, but more common in SBO)
• a sick child who cannot stand up for KUB is concerning
• CT scans can show more detail, e.g. the "point of the obstruction" but generally try to avoid CT scans in children <10 due to radiation
• if you do CT scan, should do IV contrast; used to always require oral contrast (and can be more helpful), but should be done carefully due to risk of aspiration 

Upright KUB showing SBO

• Initial treatment: NGT for decompression 
• NGT should be adequate size (if it's too small, won't work as well). An NGT an actually treat SBO by relieving the pressure
• Babies, size 10-12
• Toddlers, size 12-14
• age >7 years, size 14
• teenagers/adults, minimum size 14, better >16
• NGT has to be flushed, or it will get clogged
• If NGT is working, as evidenced by the amount coming out of NGT decreases, and child starts feeling better, you may be able to avoid surgery
• Another option after NGT: small bowel follow-through with gastrograffin (or ominpaque) can be diagnostic AND therapeutic
• 25-50cc, repeat KUB 6-12 hours after administration: decreases hospital stay either because quicker to OR vs. able to discharge home
• Hydration and serial abdominal exams are important in SBO

Midgut volvulus is the most urgent cause of bilious vomiting, usually in children <1 year old (85% before 6 months, 95% before 1 year)

• A true emergency is caused because mesenteric vein and artery get twisted, no blood flow to the entire small bowel (colon and first/second part of duodenum have their own blood supply)
• Can be life threatening in a few hours
• Perfectly healthy baby totally fine, suddenly starts throwing up yellow/green, call a surgeon!
• Imaging: UGI shows cutoff; x-ray may show just a stomach bubble (no other gas)
• Consequence so dire: lose entire small intestine, may never be able to survive not on TPN

Pyloric Stenosis typically thickening/hypertrophy of pyloric muscle fibers

• No one know why it happens
• Usually age 2 weeks to 2 months, classically first-born males
• Non-bilious (breastmilk or formula), progressive and persistent
• Imaging: ultrasound
• Surgery: cut open hypertrophic fibers, outer layer and spread it (pyloromyotomy)
• Typically does not recur

Appendicitis

• n/v, abdominal pain, umbilical down to RLQ
• renewed interest in conservative management with antibiotics only
• 95% of cases can be treated with antibiotics only, but 20% will recur in 1 year, 30% in 5 years
• fecolith has VERY high recurrence, should be operated lap appendectomy

Ileocolic intussusception

• generally age 6-36 months
• small part of small intestine gets stuck in large intestine
• usually due to laxity, lead point usually a lymph node, can be seen after enteritis OR after immunization (e.g. rotavirus vaccine)
• Imaging: ultrasound, "target sign"
• Reduction via radiology (air or contrast from anus into rectum, pushes the intussusception , reduces the small intestine), works large majority of time in kids without ischemia
• 10% recurrence rate-->  to OR
• Older kids need work up, lead point (e.g. lymphoma)

Hernias

• bilious vomiting, if incarcerated
• remember to take off vomiting baby's diaper to look for non-reduceable hernia