Know Thy Shelf: Pediatrics

  • /Reviewed by: Amy Rontal, MD
  • Your pediatric rotation is different from all others. Unless you’re going into the field, it’s the only one where your patients are all children, a population that presents its own particular set of challenges. You will encounter ultra-concerned parents who won’t want medical students to touch their precious child with a 10-foot pole. You will accidentally strike fear into the hearts of 3-year olds, despite your best efforts to be fun-loving and non-threatening. The rotation is hard enough as it is, and then the NBME throws a shelf at you. How unkind! Like your first cadaver, let’s dissect this exam and see what tips and tricks we can use to focus our efforts.

    High-Yield Study Tips for the Pediatrics Shelf Exam

    1. Know Normal

    Boring, uneventful…”normal.” A lot of vignettes on your pediatric shelf will be just that. They will give you a long-winded presentation of a pediatric patient, riddled with esoteric phrases that make him or her seem like a real problem child. The NBME is very adept at making us question normal behavior with some elegant wordplay.

    The three-year-old girl with the “inability to sit still.” The 16-year-old girl who is having sexual intercourse and has tried smoking cigarettes. The 14-month-old child who hasn’t “developed the necessary motor skill for ambulation.” With some colorful language, all of these normal patients sound like they carry a pathology. But it’s crucial to remember that toddlers and young children are sometimes difficult to direct; they are balls of energy that love to play. Teenagers are in a phase of life that revolves around experimentation and pushing boundaries.

    Normal childhood development is a highly tested topic. Remember, the benchmarks that you’ve set in your mind are usually the 50th percentile. While mom and dad might freak out when baby isn’t strolling around on Day 366 of life, it’s perfectly acceptable to start walking a couple of months later. Take a peek at the Denver II Developmental chart (Figure 1) to appreciate the wide ranges of “normal” for milestones that we usually timestamp with a single number.

    That said, some things are definitely not normal: bloody diarrhea, a lethargic infant (think sepsis/meningitis), and failing all of one’s classes come to mind. Use your judgement, but don’t fall into the NBME trap of a negative description of normal.

    Figure 1.

    2. Know your pediatric vitals

    Your patient presents with a heart rate of 150, respiratory rate of 40, and BP of 60/40. Is it a 37-year-old man after a motor vehicle collision with hemodynamic instability, knocking on death’s door? Or a happy baby, fresh out of the womb, healthy as an ox? Well, on the pediatric shelf, probably the latter. The idea is that vitals that would otherwise be terrifying in adults are quite normal in the pediatric population. As a general rule, heart rate and respiratory rate will be higher, and blood pressure will be lower. At age 13, vitals start to look much more like that of an adult. While you don’t need to know the expected values at every age in between, know the general extremes of newborns and adolescents, and you can interpolate the rest. See the helpful chart below (Figure 2).

    Figure 2.

    3. Comb through your differential diagnoses

    Some bread-and-butter pediatric problems are as classic as Beethoven’s 5th. You will certainly be questioned on them, so be sure to know the subtle distinctions between items on your differential so you can properly distinguish them. Some classics include:

    GI upset: GERD, lactose intolerance, inflammatory bowel disease, gastroenteritis, malrotation, volvulus, intussusception, hypertrophic pyloric stenosis, Hirschprung’s disease, etc.

    Limp: Septic Arthritis, Legg Calve Perthes, slipped capital femoral epiphysis (SCFE), transient synovitis, developmental dysplasia of the hips, stone in shoe, etc.

    As many of the presentations will be very similar, let the finer points and buzzwords guide the way. Olive-shaped mass in upper abdomen? HPS. Bloody bowel movements and target sign on ultrasound? Intussusception. Obese teenager with limp? SCFE. Inability to bear weight on leg, febrile, and ill appearing? Rule out septic arthritis!

    4. READ.

    I almost went without saying this one, but couldn’t help myself. Depending on the size of your hospital’s pediatric department, there is a good chance that you’re not going to have a breadth of exposure from NICU preemies to adolescent outpatient health. You will have no choice but to pick up the slack by reading.

    But what to read? We recommend a narrative style book like Case Files Pediatrics, supplemented with some form of question based vignettes, like PreTest Pediatrics. Sprinkle with all the pediatric UWorld questions and you can be confident you’ve covered your bases.

    As always, don’t let the desire to read books prevent you from offering top quality care to your patients and knowing everything there is to know about them. Your fellow students and residents will appreciate diligence in completing the shared workload much more than they will appreciate your dedication to holing up and reading.

    One last thing: when confronted with behavioral problems, always assess how the child is doing in school! If there’s only problems at school, then the problem is likely a school-related problem and not a proper pathology. If the child has more A’s than “analgesia,” consider an issue with the family dynamic. Significant problems in both arenas could indicate a true personality disorder or attention deficit disorder.

    Looking for additional pediatrics resources? Here are our recommended Step 2 CK resources to use on your pediatrics rotation.