Assessing dehydration severity and choosing the right rehydration are core CPN skills. Practice the assessment, oral-rehydration, and fluid-deficit scenarios below with full rationales.
Question 1
A 2-year-old with sickle cell anemia is brought to the clinic with a sudden onset of pallor and lethargy. The nurse practitioner palpates a firm, rapidly expanding mass in the left upper quadrant. Which action is most appropriate?
- A) Reassure the parents that this is a benign finding.
- B) Prepare for an emergency packed red blood cell transfusion.✓
- C) Administer a warm enema to relieve suspected fecal impaction.
- D) Instruct the parents to increase the child's oral hydration.
Show rationale
A rapidly expanding mass in the left upper quadrant of a toddler with sickle cell anemia, accompanied by pallor and lethargy, is the hallmark presentation of a splenic sequestration crisis. This occurs when a massive amount of blood pools in the spleen, leading to acute hypovolemia and severe anemia. The most critical intervention is to prepare for a transfusion to restore intravascular volume and oxygen-carrying capacity. Reassuring the parents (Option A) is dangerous, as this is a life-threatening medical emergency that can lead to cardiovascular collapse. Administering an enema (Option C) is inappropriate because the mass is the engorged spleen, not a fecal impaction in the descending colon. While oral hydration (Option D) is helpful for uncomplicated vaso-occlusive crises, it is entirely insufficient for the profound hypovolemic shock seen in acute sequestration.
Question 2
An 18-month-old toddler is evaluated in a cold triage room for vomiting. The nurse notes a peripheral capillary refill time of 4 seconds.
- A) Initiate rapid intravenous fluid resuscitation for severe hypovolemic shock.
- B) Reassess capillary refill centrally on the sternum to verify perfusion.✓
- C) Document the finding as a normal physiological response to vomiting.
- D) Administer a warm oral rehydration solution to improve peripheral flow.
Show rationale
Ambient cold causes peripheral vasoconstriction, which can falsely prolong peripheral capillary refill time. Option B is best because assessing central refill on the sternum provides a more accurate reflection of core perfusion. Option A is premature without confirming true hypoperfusion through central assessment or other vital signs. Option C is incorrect because a 4-second refill is never a normal physiological response to vomiting alone. Option D is inappropriate as oral fluids do not immediately reverse cold-induced peripheral vasoconstriction.
Question 3
A parent uses a rural telehealth portal to report their 4-month-old infant has had watery diarrhea for three days. During the video assessment, the nurse observes the infant is lethargic with sunken eyes and no tears when crying. Which recommendation is most appropriate for this patient?
- A) Instruct the parent to administer oral rehydration solutions every fifteen minutes.
- B) Prescribe a pediatric antidiarrheal medication and schedule a morning follow-up.
- C) Direct the parent to take the infant to the nearest emergency department.✓
- D) Guide the parent through a focused abdominal examination using the camera.
Show rationale
Telehealth is excellent for minor triage, but a 4-month-old with watery diarrhea for three days and signs of severe dehydration like sunken eyes and no tears requires immediate physical intervention. Option C is correct because intravenous fluid resuscitation is likely needed. Option A and Option B dangerously delay critical care for an unstable infant. Option D is inappropriate because an abdominal exam via camera does not resolve the immediate threat of severe hypovolemia.
Question 4
A 2-year-old toddler is brought in with a three-day history of severe diarrhea and vomiting. The triage nurse notes the child is profoundly lethargic, has sunken eyes, and exhibits a capillary refill time of four seconds.
- A) Prioritize as non-urgent due to viral etiology.
- B) Prioritize as urgent due to fluid requirements.
- C) Prioritize as fast-track due to common symptoms.
- D) Prioritize as emergent due to altered perfusion.✓
Show rationale
The child is demonstrating signs of severe dehydration and impending hypovolemic shock, evidenced by profound lethargy and delayed capillary refill. Option D is correct because these findings represent a high-risk, life-threatening condition requiring immediate fluid resuscitation, fitting the emergent triage category. Option A is incorrect because the severity of the symptoms completely overrides the likely viral etiology. Option B is incorrect because urgent classification underestimates the immediate threat to life posed by altered perfusion and lethargy. Option C is incorrect because fast-track is completely unsafe for a hemodynamically unstable pediatric patient.
Question 5
A 10-year-old with a recent ventriculoperitoneal shunt revision presents with lethargy. Over the last hour, the nurse notes a blood pressure of 148/62 and a heart rate of 54. These specific findings most likely indicate which clinical state?
- A) Impending brainstem herniation from elevated intracranial pressure.✓
- B) Decompensated hypovolemic shock from undetected internal bleeding.
- C) Early shunt malfunction requiring rapid fluid resuscitation.
- D) Systemic inflammatory response from a severe shunt infection.
Show rationale
The patient is exhibiting signs of Cushing triad, which includes hypertension with a widening pulse pressure, bradycardia, and irregular respirations. This is a very late and ominous sign of severely increased intracranial pressure and impending brainstem herniation, making option A the correct choice. Option B is incorrect because hypovolemic shock typically presents with tachycardia and hypotension, not bradycardia and hypertension. Option C is incorrect because these vital sign changes represent a late, life-threatening emergency rather than an early malfunction, and fluid resuscitation could worsen cerebral edema. Option D is incorrect because a systemic infection would typically present with fever, tachycardia, and potentially hypotension, rather than the classic bradycardic and hypertensive response seen here.
Question 6
An infant with congenital heart disease has a pulse oximeter on the right wrist and a noninvasive blood pressure cuff on the right upper arm. The SpO2 drops intermittently.
- A) Change the blood pressure cuff to continuous mode.
- B) Secure the oximeter probe with clear medical tape.
- C) Administer the prescribed fluid bolus for systemic hypotension.
- D) Relocate the pulse oximeter to the left foot.✓
Show rationale
Placing a pulse oximeter distal to a blood pressure cuff causes venous congestion and a temporary loss of pulsatile flow during cuff inflation, resulting in false desaturation alarms. Relocating the sensor to a different limb prevents this mechanical interference. Changing the blood pressure cuff to continuous mode would actually worsen the artifact by constantly occluding flow. Taping the probe does not fix the flow interruption. A fluid bolus treats hypovolemia, not mechanical interference caused by routine cuff inflation.
Question 7
A father is preparing powdered formula for his 4-month-old healthy infant. He places three scoops of powder into an empty bottle and then adds water up to the 6-ounce line. What is the primary risk associated with this preparation method?
- A) The infant may develop hypernatremia from overly concentrated formula.✓
- B) The infant may experience water intoxication from diluted formula.
- C) The formula will lack sufficient calories for adequate growth.
- D) The formula will be too difficult to digest properly.
Show rationale
Proper preparation requires adding water to the desired line first, then adding the powder. Putting powder in first displaces the water, resulting in less water than required. This creates an overly concentrated mixture, which can lead to dehydration and hypernatremia. Option B is incorrect because the mixture is concentrated, not diluted. Option C is incorrect because the caloric density per ounce actually increases, though it is unsafe for the infant's kidneys. Option D is vague and does not address the specific physiological danger of improper mixing ratios.
Question 8
A 15-year-old with contamination-focused obsessive-compulsive disorder is refusing to use school restrooms and is intentionally restricting daytime fluid intake. Which assessment is the highest priority for this patient?
- A) Evaluate the physiological effects of these avoidance behaviors.✓
- B) Assess the immediate need for homebound educational instruction.
- C) Screen for underlying body dysmorphic disorder clinical traits.
- D) Determine the presence of a comorbid social phobia.
Show rationale
When a child with contamination OCD is refusing to use school restrooms and restricting daytime fluid intake, the primary concern is the physical consequence of these actions. Avoidance is a core component of OCD that severely impacts daily functioning, and in this case, it can lead to dehydration or urinary retention. Option A is correct because evaluating the physiological effects of these avoidance behaviors addresses the most immediate threat to the child's health. Option B is incorrect; homebound instruction is a last resort and does not address the underlying avoidance behavior. Option C is incorrect; body dysmorphic disorder involves perceived flaws in appearance, which does not align with contamination fears. Option D is incorrect because the isolation stems from contamination fears and avoidance rituals, not from a primary fear of social scrutiny.
Question 9
A 16-year-old with cystic fibrosis is joining the summer outdoor track team while maintaining a high-calorie and high-fat diet. Which additional dietary instruction is essential for this adolescent?
- A) Decrease daily fat intake to improve running speed.
- B) Restrict daily fluid intake to prevent exercise coughing.
- C) Increase dietary sodium intake with salty sports snacks.✓
- D) Discontinue pancreatic enzymes before engaging in track practice.
Show rationale
Patients with CF experience excessive sodium loss in their sweat, which significantly increases during hot weather and physical exertion. Therefore, they require proactive salt supplementation using salty snacks or sports drinks to prevent hyponatremia and dehydration. Decreasing fat intake (Option A) is contraindicated because these athletes need maximum calories to maintain their baseline weight. Restricting fluids (Option B) is dangerous and increases the risk of dehydration and thick mucus plugging. Pancreatic enzymes (Option D) must be continued with all fat-containing meals and snacks to ensure the athlete absorbs the nutrients needed for energy.
Question 10
A 4-year-old patient is being evaluated two hours post-tonsillectomy. The nurse observes the child is irritable, has a heart rate of 110 bpm, and just vomited 30 mL of dark brown fluid.
- A) Notify the surgeon immediately of a suspected primary postoperative hemorrhage.
- B) Prepare to administer a fluid bolus to treat early hypovolemic shock.
- C) Provide oral care and continue to monitor the child's vital signs.✓
- D) Insert a nasogastric tube to decompress the stomach and prevent aspiration.
Show rationale
Dark brown or coffee-ground emesis is an expected finding shortly after a tonsillectomy due to swallowed blood during the surgical procedure. A heart rate of 110 bpm is within normal limits for a four-year-old, and irritability is common as anesthesia wears off. Providing oral care and continuing to monitor is the most appropriate action. Notifying the surgeon is unnecessary because this does not represent active, bright red bleeding. Preparing a fluid bolus is incorrect since the child's vital signs do not indicate hypovolemia or shock. Inserting a nasogastric tube is contraindicated as it can cause trauma to the surgical site and trigger a primary hemorrhage.
Question 11
A 2-year-old with congenital heart disease and failure to thrive is seen in the clinic two days after an emergency department visit for dehydration.
- A) Review the emergency department discharge summary and reconcile current medications.✓
- B) Refer the child to a pediatric gastroenterologist for feeding evaluation.
- C) Schedule a follow-up appointment with the pediatric cardiologist next month.
- D) Instruct the parents to increase the child's daily caloric intake.
Show rationale
A core function of the medical home is providing continuous care and preventing fragmentation after acute events. Performing medication reconciliation and reviewing the ED summary ensures safety and continuity for a medically complex child. Option B might be needed eventually but ignores the immediate post-ED transition needs. Option C delays necessary acute follow-up and assumes the cardiologist should manage the dehydration aftermath. Option D is a generic intervention that doesn't address the recent acute dehydration event or ensure safe transitions of care.
Question 12
A 4-week-old male is brought to the clinic with a history of projectile vomiting after feeds. On examination, the nurse practitioner palpates a firm, olive-shaped mass in the right upper quadrant. Which intervention is most appropriate?
- A) Administer a trial of oral rehydration solution slowly.
- B) Prepare the infant for an immediate barium enema.
- C) Initiate intravenous fluid therapy and keep the infant NPO.✓
- D) Perform deep palpation to assess for rebound tenderness.
Show rationale
The presentation of projectile vomiting and a palpable olive-shaped mass in the right upper quadrant of a young infant is the classic clinical picture of pyloric stenosis. These infants frequently develop severe dehydration and hypochloremic metabolic alkalosis. The immediate priority is to initiate intravenous fluids to stabilize their hydration and electrolyte status while keeping them NPO in preparation for a pyloromyotomy. Administering oral rehydration (Option A) is contraindicated because the gastric outlet obstruction will simply cause further vomiting and fluid loss. A barium enema (Option B) is the diagnostic and therapeutic choice for intussusception, not pyloric stenosis, which is typically confirmed via ultrasound. Performing deep palpation for rebound tenderness (Option D) is unnecessary, causes undue discomfort, and does not aid in managing this specific hypertrophic obstruction.
Question 13
A 9-month-old infant presents to the emergency department with a sunken anterior fontanel and a history of three days of diarrhea. The infant appears lethargic. Which intervention is most appropriate?
- A) Prepare for a lumbar puncture to rule out viral meningitis.
- B) Initiate oral or intravenous rehydration therapy as ordered immediately.✓
- C) Measure the head circumference to check for developing hydrocephalus.
- D) Administer a prescribed antiemetic to prevent further fluid losses.
Show rationale
A sunken fontanel in the context of prolonged diarrhea and lethargy is a classic sign of moderate to severe dehydration. The immediate priority is restoring intravascular volume through fluid replacement therapy. Option A is incorrect because a sunken fontanel points to fluid deficit, whereas meningitis typically presents with a bulging fontanel due to increased pressure. Option C is unnecessary as hydrocephalus causes a bulging fontanel and macrocephaly, not a sunken one. Option D is inappropriate because while an antiemetic might stop vomiting, it does not replace the critical fluid deficit already present from the diarrhea.
Question 14
A 5-year-old child with moderate dehydration secondary to viral gastroenteritis has successfully completed four hours of oral rehydration therapy. The child is now playful, with moist mucous membranes, and requests food.
- A) Resume a regular, age-appropriate diet immediately to support enterocyte recovery.✓
- B) Restrict dietary intake to the BRAT diet for twenty-four hours.
- C) Maintain a clear liquid diet until stools return to normal.
- D) Administer maintenance intravenous fluids while slowly introducing complex carbohydrates orally.
Show rationale
Once a child is successfully rehydrated and clinically stable, early refeeding is highly recommended. Option A is correct because an age-appropriate diet helps repair the intestinal mucosa and reduces the duration of diarrhea. Option B is incorrect; the BRAT diet is unnecessarily restrictive and lacks adequate protein and calories for recovery. Option C is incorrect because prolonged clear liquid diets can lead to starvation stools and delayed mucosal healing. Option D is unnecessary and invasive, as the child is already rehydrated and tolerating oral intake perfectly well.
Question 15
A 4-year-old post-appendectomy patient has new-onset tachycardia and diaphoresis without fever. The patient is guarding the abdomen. What is the most appropriate interpretation?
- A) The child is developing early hypovolemic shock.
- B) The child is experiencing an acute pain episode.✓
- C) The child is exhibiting signs of systemic infection.
- D) The child is manifesting expected postoperative anxiety.
Show rationale
Acute pain triggers a robust sympathetic nervous system response, leading to physiologic changes like tachycardia and diaphoresis. When assessing this post-appendectomy patient, the new onset of these signs paired with abdominal guarding strongly points to a localized pain episode. Option B is the best choice because it synthesizes all the clinical cues. Option A is incorrect because early hypovolemic shock would typically present with additional signs like delayed capillary refill or altered mental status, and guarding is specific to pain. Option C is incorrect because the patient explicitly lacks a fever, which makes a systemic infection highly unlikely. Option D is incorrect because while anxiety can cause an elevated heart rate, the presence of diaphoresis and physical guarding indicates a primary nociceptive issue rather than isolated psychological distress.
