Case Study 5 Activity
docx
keyboard_arrow_up
School
Miller-Motte Technical College, Cary *
*We aren’t endorsed by this school
Course
4000
Subject
Medicine
Date
Apr 3, 2024
Type
docx
Pages
5
Uploaded by SuperHumanFreedomDragon25
Part I – A Very Bad Day
“Doctor, come quickly. We’re losing the patient!”
“Losing the patient? How can we be losing the patient? I’m still scrubbing!” Dr. Lopez walked into the operating room. “John, what’s going on?”
“Glad you’re here, Lyanna. We could use a hand. This patient is not happy with the anesthetic.” John Smith, the anesthesiologist, was hovering over the patient’s head and giving orders to nurses nearby.
Lyanna Lopez, an orthopedic surgeon, surveyed the scene. This patient was here for minor surgery. He had been complaining of knee pain. As a seasoned athlete herself, Dr. Lopez had agreed to “clean up” some loose connective tissue in the patient’s knee – the result of an old injury.
Dr. Lopez couldn’t believe what she was seeing. The patient was rigid, and his skin looked patchy; in some places it was almost blue. “How are his vitals?”
“Breathing is rapid, heart rate at 120, pressure is 60/56 and his temperature is 106.”
Lyanna quickly made her way to the head of the table. “How can I help?” The doctors consulted and a flurry of activity filled the room.
In the corner of the room, a small 18-year-old girl stood staring at the scene. She was pale as a ghost. Softly, two questions drifted from her corner to the doctors. “What’s wrong with that man? Is he going to die?”
Questions- Part I
1.
Fill in the chart below. Use “+” if the patient’s vital sign is higher than normal, “−” if the sign is lower than normal, or “x” if the sign is normal. If you need to, use your text or another resource to determine normal values.
Vital Sign
Increase/Decrease/Normal
Respiration Rate
+
Heart Rate
+
Blood Pressure
-
Body Temperature
+
2.
If you were the doctors on the scene, what diagnosis would you give this patient? (You may use the internet to help diagnose the patient.)
Malignant Hyperthermia Part II – A Veritable Metabolic Storm
Both doctors turned to the corner to see Brooke, Dr. Smith’s niece. She was visiting the hospital as an
assignment for her high school biology class. She was supposed to be shadowing a doctor for the day
and would need to report back to her class with what she saw and did.
“Brooke, why don’t you come over here and I will explain what is going on.”
Brooke gave her uncle a tentative look and crossed the room. She stood several feet away from the
table, not wanting to look at the patient. After several minutes, which seemed to last for hours, the
activity in the room slowed down and the doctors gave the nurses a few simple instructions. The man
would survive.
John, Brooke’s uncle, spoke first. “This patient just had a bad reaction to the anesthetic. His temperature
rose very rapidly, which can be dangerous to your organs. The same sort of thing can happen when you
have a bad fever.
We just removed the anesthetic and are bringing his temperature back down. This condition is called
malignant hyperthermia, and, yes, people can and have died from it. Fortunately, today we caught the
problem in time, and I think we moved quickly enough to prevent any permanent problems. We won’t
be doing this surgery today.”
Brooke looked at her uncle in disbelief. Malignant hyperthermia? This man could have died? She never
thought shadowing an anesthesiologist would be so…exciting? terrifying? She wasn’t sure what exactly,
but she was sure her class would love the story.
She looked at the doctors. “What causes malignant hyperthermia?”
Te doctors looked at each other. “John, I think this question is for you. If you don’t need me, I think I will
go question the family for a bit more of their medical history and to warn them that genetics are a factor
here—they may want to report this to their general practitioners in the future.” With a wink and a wave
to Brooke, Dr. Lopez left the operating room. Behind her, the nurses began wheeling the patient out of
the operating room and into the recovery room.
Brooke looked at her uncle, “Well?’
“Malignant hyperthermia is a genetic condition,” he began, “which causes the patient’s temperature to
rise to a dangerously high level when they are exposed to certain anesthetics. Patients with MH also get
muscle rigidity, which is why that poor gentleman looked so stiff after I started administering anesthetic.
They also have changes in breathing, heart rate, and blood pressure. All of these can be dangerous, but
the changes that are seen in muscle are at the heart of the problem. As the muscles get tense, they also
become damaged, which releases chemicals into a person’s blood stream. As my professor in med.
school put it, ‘MH causes a veritable metabolic storm.’”
“A veritable storm?” began Brooke. “I’m not sure I get it. Do you have anything I can read that explains
the disease in English?” She smiled at her uncle, hoping he got the joke.
“You know what,” her uncle smiled back. “I think I might have some information that will help.” Clearly,
he wasn’t offended.
Questions- Part II
1.
Read the following sections of the supplemental reading uploaded on Canvas- Making
Anesthesia Safer: Unraveling the Malignant Hyperthermia Puzzle o
Anesthesia triggers multiple-familial deaths
o
The first signs
o
Serendipitous discovery of an experimental model
2.
In the above supplemental information article, what is the “veritable metabolic storm” that the
author refers to? What molecular changes are reported in pig muscles during a MH state?
A veritable metabolic storm is when there is a rapid and severe metabolic response to anesthesia. There
is a massive release of ATP, calcium, acid, and calcium from the sarcoplasmic reticulum in skeletal cells
releasing to uncontrolled muscle contractions. 3.
Review muscle contraction. Send one person in your group to collect the “Steps of Muscle
Contraction” cards from your instructor. In your group, arrange these cards in correct order to represent
what happens during muscle contraction. (
we will do this in the zoom class on Thursday!)
4.
When you have placed all the cards in correct order, prepare a list (below) of the steps that
require ATP or Ca2+. (
we will do this in the zoom class on Thursday!)
o
Steps that require ATP: o
Steps that require Ca2+: Part III – Am I Susceptible?
After a long shift in the operating room, John was catching a few winks on a bed in the hospital. He was
just drifting of when his cell phone rang loudly in his pocket.
“Hi Uncle John,” Brooke said cheerily. “Do you have a second?’ “For you, anything,” John replied, sitting
up.
Brooke began, “I was telling a friend about my time at the hospital, and she asked me a question I didn’t
know the answer to. I read the information you gave me, and the answer wasn’t there either. We were
wondering, how do you know if you have malignant hyperthermia? You don’t find out the first time you
have surgery, do you?”
John smiled. His niece surely was inquisitive, and her questions were spot on—he’d swear someday she
would be a doctor.
“Well,” he started, “you know the reading I gave you also had information about pigs. In pigs, you can
simply give them a little anesthetic and see if their muscles go rigid. Most of the time, when you remove
the anesthetic, the pig will go on to live a normal life. In humans, though, that technique would be too
risky—and that kind of testing in humans is unethical. Instead, scientists have come up with a way to
test muscle biopsies. Do you know what a biopsy is?”
“That’s when a doctor takes a small sample from your body,” Brooke said. “Right?”
“Yep,” her uncle replied through a yawn, “Well, there are centers across the U.S. where people who
think they may be susceptible can meet with scientists and run some tests. The scientists take some
muscle biopsies, and then put them in a bath with chemicals that are like blood. They then expose the
biopsies to anesthetics and test which muscles contract the most forcibly. From what you know about
MH, can you guess which contracts with the most force, healthy muscle, or muscle susceptible to MH?
You know what, I will mail you some more information on this topic.”
Questions- Part III
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
1.
Predict if healthy muscle or muscle with MH will contract with the most force.
Muscle with MH would contract with the most force. 2.
To check you answer to the first question, read the following sections of the supplemental
reading uploaded on Canvas- Making Anesthesia Safer: Unraveling the Malignant Hyperthermia Puzzle. o
Working together to discover the triggers
o
Predicting susceptibility in humans
o
Developing a grading scale
2.
Even though screening tests exist, most people aren’t checked for the disease. Why not?
What types of people (or what populations) would be most likely to be screened before they
had their first surgery?
MH has a low probability, about 1 in 5,000 experience MH resulting in less screening for it. Individuals
with specific genetic mutations associated with MH like RYR1 and CACNA1S would show up in a
screening. Individuals who have family history of MH, patients with known genetic mutations, patients
undergoing high-risk surgical procedures, and as mentioned in the supplemental reading, young males
are also part of the population of people who should be screened before their first surgery. Citation for this question: Rosenberg, H., Davis, M., James, D., Pollock, N., & Stowell, K. (2007).
Malignant hyperthermia. Orphanet journal of rare diseases
, 2
, 21. https://doi.org/10.1186/1750-1172-2-
21
Part IV – Show and Tell
A couple days later, as Brooke was preparing for her class presentation, a package arrived in the mail for
her. She tore the package open to find more information from her uncle, and a short note:
I know your presentation is coming up soon. I thought this would help. Let me know if you have more
questions. It was a treat to have you visit me at work. You are welcome to come back and watch
anytime. I get the feeling after this visit that we might soon have another doctor in the family.
Love, Uncle John
“Just in time!” Brooke cried. After reading the information, she sat at her desk trying to develop an
outline for the presentation. After a few minutes, she realized that what had driven her learning about
the disease were the questions she had asked. She decided that questions could guide her presentation,
and she settled on an outline for her presentation that focused on the questions listed below.
Questions- Part IV
1.
Read the following sections of the supplemental reading uploaded on Canvas- Making
Anesthesia Safer: Unraveling the Malignant Hyperthermia Puzzle.
o
Preventing death after onset
o
Disseminating what we know
o
Why patients are still dying
o
Understanding the biology of MH
o
What’s next?
2.
Prepare short answers for each question in Brooke’s outline.
o
How do muscles contract?
Muscles contract when signals from the nerves prompt the release of calcium, which bind to proteins in
muscle cells and initiates a series of reaction that cause muscle fibers to slide past each other. o
What is malignant hyperthermia?
MH is a rare genetic condition where certain anesthetic agents trigger uncontrolled muscle contractions
and a tremendous increase in body temperature. o
What triggers malignant hyperthermia?
MH is triggered by exposure to specific anesthesia drugs, leading to a “metabolic storm” marked by
elevated metabolism and muscle rigidity or muscle spasms. o
What is the “metabolic storm” that develops during malignant hyperthermia?
The metabolic storm disrupts muscle physiology by causing an excessive amount of calcium to release
leading to muscle contractions/rigidity and hypermetabolism. o
How does malignant hyperthermia disrupt muscle physiology?
It disrupts muscle physiology by causing uncontrolled release of calcium ions from the sarcoplasmic
reticulum. o
Why does body temperature rise during malignant hyperthermia?
Body temperature rises due to increased metabolism and increased heat production. o
How can you tell if you have malignant hyperthermia?
MH can be suspected if a patient develops muscle rigidity, muscle contractions, high body temperature,
and metabolic acidosis during anesthesia. o
What drug is used to treat malignant hyperthermia and what are the mechanisms of action
of how this drug works?
Dantrolene is a drug used to treat MH by blocking calcium release form muscle cells and preventing
further muscle contractions. o
Why doesn’t the antidote to malignant hyperthermia impact smooth or cardiac muscle?
The antidote doesn’t impact smooth or cardia muscle because they primarily rely on different
mechanisms for calcium regulation and are less affected by dantrolene’s actions. Adapted from content created by K.W.Grorud (Edgewood college)