Candice was a high school student on the track team and
training for her upcoming cross-country meet. She woke up bright
and early to complete a 10-mile run. Her workout ended up taking
her a little longer than usual and she was sweating
As Candice cooled down from her run, Candice’s Mom yelled from
the kitchen, “Candice, your breakfast is ready! Come eat. You look
“Oh, really? I’m starving; maybe that’s why? What did you
“Your favorite... eggs benedict with a side of toast and
orange juice. So, how was your run? It seemed like it took you
longer than usual.”
“I felt a little more tired than I usually do, but I stayed
strong. Nothing to worry about,” Candice assured her.
“You need to stay healthy for the invitational meet on
Saturday. As you well know, your performance on Saturday will
determine your eligibility for states. Maybe you should reschedule
your date with ... ”
“Mom! I’ll be fine. Trust me,” Candice exclaimed.
Candice finished her breakfast and, while taking a hot shower,
felt a cramp developing in her left leg. Not thinking too much
about it she took a naproxen tablet, rubbed the cramp and proceeded
on with her day. After studying for about an hour she realized that
the naproxen wasn’t working because her muscles still felt sore.
Oh, no…this is bad timing. I have a date with Phil tonight, Candice
thought. So, she took another naproxen tablet.
Half an hour later, Candice felt dizzy and lightheaded and her
skin began to feel clammy, which she believed was due to the
humidity. She felt her heart race and tried to calm herself, but
the leg cramps started coming back. Although Candice prided herself
on a high threshold for pain, she finally told her mom that
something was wrong and that she needed to go to the
List the problems that Candice experienced.
Can you see any common features in Candice’s problems?
Do you think Candice overreacted by saying she wanted to go to
Do you have a prognosis for Candice’s problems?
“Candice, honey, I think you’re overreacting. How about I take
you to the urgent care?”
The nurse at the urgent care took Candice’s history and
History and Physical Report
Patient Candice Pearson
Chief complaint: Lightheadedness, fatigue, muscle cramps
Past medical history: Polycystic ovarian syndrome [Treatment →
150 mg spironolactone daily]
Past surgical history: Wisdom teeth removed (3 months
Weight: 130 lbs.
Drug allergies: Penicillin
Heart rate: 110 beats/min (normal: 60–100)
Blood pressure: 98/56 (normal: 120/80)
Pinch skin: skin bounces back slowly
History and Physical Report Patient: Candice Pearson History
Physical Chief complaint: Lightheadedness, fatigue, muscle cramps
Past medical history: Polycystic ovarian syndrome [Treatment → 150
mg spironolactone daily] Past surgical history: Wisdom teeth
removed (3 months ago) Drug allergies: Penicillin Age: 17 Height:
5´6˝ Weight: 130 lbs. Temperature: 97.8° Heart rate: 110 beats/min
(normal: 60–100) Blood pressure: 98/56 (normal: 120/80) Pinch skin:
skin bounces back slowly.
“Wow, Mom, my heart rate’s high; it’s usually around
“Maybe you’re just nervous, honey.”
The nurse decided that Candice was probably experiencing
dehydration from her run. She recommended rest and drinking plenty
of fluids like water and Gatorade.
What new information has been revealed?
Which of Candice’s problems could have been caused by
Which problems could have been caused by something other than
Where is blood pressure monitored in your body?
Which part of the autonomic nervous system is activated when
blood pressure is low?
What is the effect of this part of the autonomic nervous
system on heart rate and stroke volume?
If Candice is correct and her resting heart rate is usually
around 60, why is her blood pressure low?
Would you like to change or modify your prognosis?
After driving home from urgent care, Candice began to get
ready for her big date night with Phil. She had a new dress picked
out and invited her friend, Maria, over to help with her hair and
“You look great! Phil’s going to be blown away,” Maria
encouraged her friend.
“I hope so. Though, I’m still a little nervous. I think I’m
going to take a couple of my prescription pills. I missed my dose
“Are you sure?” Maria asked.
“Yeah, it’s alright. And I think it makes me look and feel
better,” Candice said reassuringly.
Phil arrived to pick up Candice for the date. Ever the
gentleman, he had picked out a nice romantic Italian restaurant.
Candice ordered spaghetti marinara and Phil ordered fettuccine
They finished dinner and headed to the movies. Candice was not
a fan of scary movies but agreed because Phil wanted to see it.
About halfway through the movie, she started feeling a little
light-headed and her heart started racing. It’s probably the blood
in the scary movie messing with me, she thought. She tried to calm
herself, not wanting to ruin their first date.
She turned to Phil, “Sorry, but I think something’s wrong! I
feel sick!” Phil guided her out of the movie theater, where she
then collapsed and complained that her chest felt really tight.
Candice thought to herself, Oh no, I think I’m going to be sick.
How embarrassing! There isn’t going to be a second date.
Phil called 911 and an ambulance quickly arrived.
Make a list of any new problems Candice is experiencing. Do
any of Candice’s new problems correlate with your previous
Why is Candice having chest tightness?
How does the nurse’s diagnosis of dehydration affect the blood
pressure and circulation?
What did Candice eat for dinner? How could her food choice at
dinner cause these problems?
List tests that the doctors should perform at the
Candice’s mother arrived at the hospital as the EMT moved
Candice into the emergency room where she was placed under the care
of a new resident. The resident began to check her vitals and took
a report of Candice’s problems while her mother anxiously paced
back and forth. He then listened to her breathing sounds, which
appeared normal. Next, the resident ordered an ECG, chest x-ray, CT
brain scan, and metabolic profile of Candice’s blood work. In the
meantime, he asked about her previous medical history, any
medication she was currently on, and what she ate recently.
“I just ate spaghetti marinara. I am on spironolactone because
I have polycystic ovarian syndrome. I took two tablets right before
dinner because I forgot to take it this morning. After my run
earlier in the day, I had intense muscle cramps so I ended up
taking two naproxen tablets. I was starting to feel better in the
afternoon so I thought I would be okay to go on my date.”
The resident asked, “How much water did you drink
“Not much,” Candice admitted ashamedly.
“Well, you should know spironolactone is a diuretic. Your
physician should have told you to drink plenty of water when you
are taking this drug. It works as an aldosterone receptor
antagonist in the cells of the distal tubule in your kidney, which
means that you will lose a lot of water. You need to stay
hydrated,” warned the resident.
The resident then left to pick up the test results.
Fill in the table to predict the results of the initial
Aldosterone is responsible for controlling blood sodium and
potassium levels. What type of hormone is aldosterone and which
cells secrete it?
The resident returned with the tests results: the CT brain
scan was normal, the EKG showed an elevated heart rate with
arrhythmia, the chest x-ray was normal, and the blood work showed
an electrolyte imbalance.
Here is a partial list of Candice’s blood work:
Glucose, Serum (mg/dL)
Uric Acid, Serum (mg/dL)
Creatinine, Serum (mg/dL)
Sodium, Serum (mEq/L)
Potassium, Serum (mEq/L)
Chloride, Serum (mEq/L)
Calcium, Serum (mg/dL)
20. What abnormal values are evident in Candice’s blood
21. What could cause an elevated heart rate?
22. What minerals do tomatoes have in high
23. Could the tomatoes have had an effect on the level of that
mineral in Candice’s blood?
24. Use the Nernst equation (below) to calculate the
equilibrium potential for potassium in a normal patient and in
Candice; assume [K]in is 150 mEq/L in Candice and in normal
patients, and [K]out is 4 mEq/L in normal patients.
E K+ (millivolts) = 61 log10 ([K+ ] out /[K+ ] in)
25. If the resting membrane potential exhibits the same change
as the equilibrium potential for potassium, predict how Candice’s
ion imbalance will affect a cell’s resting membrane potential;
would Candice’s resting membrane potential be hyperpolarized or
The resident and attending returned and talked to Candice and
“Candice, you are suffering from hyperkalemia, which means you
have more potassium in your blood than normal. Two things happened
to you today to create the perfect storm. First, you ate a meal
high in potassium and second you took a high dose of
spironolactone. The drug blocks the action of a hormone in your
body called aldosterone, which works to rid your body of excess
potassium, exchanging it for sodium. Decreased aldosterone activity
means the level of potassium in your blood increased while the
level of sodium decreased. Also, the loss of sodium in your urine
causes you to also lose water.”
“So I guess that’s why it’s a diuretic,” interrupted
“Exactly. The elevated potassium levels in the fluid around
your cells is responsible for your heart arrhythmia, high heart
rate, and muscle cramps. I recommend staying away from
potassium-rich foods like bananas and tomatoes.”
“Usually I do; I only eat apples and oranges.”
“I also suggest taking acetaminophen instead of NSAIDs, like
naproxen, as it is thought that there may be some drug interaction
that further increases hyperkalemia. You have to be careful what
you eat; your body is losing a lot of water and sodium so hydration
is key when you are on spironolactone. I recommend that your diet
consists of low potassium and high sodium meals as well as a lot of
water or Gatorade, especially while you are training. This could
have been a lot worse if you hadn’t come in for treatment. Are
there any concerns you would like to address?” asked the
“No. Thank you so much! I’ll try to be more careful in the
future,” said Candice.
Where is the pacemaker for the heart?
How could membrane depolarization created by elevated blood
potassium level cause an increase in Candice’s heart rate?
How could the membrane depolarization created by the elevated
blood potassium level cause arrhythmias?
How could the membrane depolarization created by the elevated
blood potassium level cause muscle cramping?