Chapter 253

Episode 253. Clean-up (3)

ㄴ Korean Slave 1 (Male): ??? OTC?? Deficiency??

ㄴ Latte is Mine: There’s no time to talk, so block it quickly!!!!!!

As soon as I saw that comment, I hurriedly sat at my computer and canceled the order.

“Nurse Jeong!”

“Yes.”

“The Depakine going into that patient right now! Shut it off quickly!”

“Ye-yes?”

Nurse Jeong, with a flustered face, hurriedly rushed toward the patient, while Choi Hyun-jin from Neurology turned his head toward me with an even more bewildered look.

“Teacher?”

“Just a moment.”

I raised my hand toward Choi Hyun-jin, making a gesture to tell him to hold on.

“Uh, what is the reason for canceling the order…? I’m the one who put it in….”

Choi Hyun-jin from Neurology trailed off, seemingly at a loss.

“There is a reason for it. Just a moment, please.”

“That’s why I need to know what the reason is so I can be convinced.”

Choi Hyun-jin replied with a dissatisfied face.

Then again, he had given a textbook, standard prescription, and suddenly an Emergency Room guy who wasn't even from a specialized department was blocking it. From Neurology's perspective, it was completely understandable to be pissed off and dumbfounded.

“If they slip into status epilepticus, the ER isn't going to take responsibility, are you?”

“We can just take responsibility.”

At my words, Choi Hyun-jin scratched the back of his neck.

“No, then… uh, why was the order canceled? If you blocked a Neurology order, you should at least provide an explanation that makes sense so I can modify the charting or leave a consult for another medication.”

He was right. However, even now, the exact pathophysiological mechanism wouldn't come to mind.

I rolled my eyes and urgently looked back at the window in the void.

ㄴ Korean Slave 1 (Male): Hurry up and produce the evidence.

ㄴ Let’s Spin the Catapult: Hell Slave, this bastard is freaking out right now, lol.

Of course I'm freaking out.

In patients with typical encephalitis or idiopathic epilepsy, administering a loading dose of valproic acid is evaluated as the standard and safest textbook treatment.

That's right. It meant that under normal circumstances, it was a neurological drug where a risk didn't even exist. Following a generalized tonic-clonic seizure, the patient had even developed focal seizures. So, on what earth could I justify blocking this order that gave valproic acid right after lorazepam?

ㄴ Latte is Mine: You know that valproic acid metabolizes in the body to form valproyl-CoA, right?

Don't know.

ㄴ Latte is Mine: As it forms, wouldn't it deplete the carnitine inside the mitochondria?

My patience is the thing being depleted right now.

Even so, there was nothing else I could do, so I just made up my mind to parrot the explanation of the ghost. But first, let’s get this damn pathophysiology lecture over with.

ㄴ Hippocrates' Descendant: Biology is always fascinating to hear! Especially when it comes to pathophysiological knowledge!

ㄴ Latte is Mine: What's even more fatal is that valproic acid inhibits carbamoyl phosphate synthetase 1, the gatekeeper enzyme of the urea cycle…!

ㄴ Korean Slave 1 (Male): Could you please give me some practical, clinical talk?

My true feelings slipped out after holding it back.

Okay, I get it. I understand how the drug works and what role it plays at our cellular level, but I have to endure the piercing gaze of the Neurology on-duty doctor.

Ah, whatever. I made up my mind to just say the diagnosis the ghost mentioned at the very beginning.

“Because the patient seems to have UCD (*Urea Cycle Disorder). Especially, I suspect an OTC deficiency.”

“…Pardon?”

To the dumbfounded Neurology on-duty doctor, I threw out one last line.

“What are you doing? Aren’t you looking up the information?”

At those words, Choi Hyun-jin from Neurology hurriedly opened his phone and started searching for something.

'I want to check Up-to-date too….'

I wanted to look at Up-to-date to directly compare and find information on the patient, but since I had already acted like I knew everything, it felt a bit awkward to do so. Even so, I'm a doctor, so I should look.

'Should I just check the treatment plan? It's not like that's anything strange.'

Just as I sat down at the computer, rationalizing it, and was about to turn on Up-to-date, the window in the void flashed.

'Sigh….'

I turned my head.

[Comments]

ㄴ Latte is Mine: So instead of valproic acid, it’s recommended to use levetiracetam or fosphenytoin as a second-line agent. Yes, yes.

ㄴ Korean Slave 1 (Male): What’s good about using them?

ㄴ Latte is Mine: They don't block the urea cycle. So if a metabolic disease is suspected, it's unconditionally better to go with these two.

'I see.'

No matter how textbook and safe a treatment is, if the medical history is unclear or if a metabolic disease is even slightly suspected, avoid valproic acid. I made up my mind to remember that fact for a very long time.

'See, this kind of information is helpful.'

ㄴ Let’s Spin the Catapult: There's no risk of raising ammonia levels either.

Old man Latte began running a helpful Q&A show all on his own.

ㄴ Latte is Mine: What does it mean that there was a headache upon protein intake?

ㄴ Korean Slave 1 (Male): Um… they didn’t like meat?

ㄴ Latte is Mine: Your brain structure is truly simple (it’s a compliment). If there is a nitrogen supply source but no enzyme to process it, what builds up?

'Aha!'

The body instinctively avoided the nitrogen source to escape the accumulation of ammonia in the system. I nodded and left a reply.

ㄴ Korean Slave 1 (Male): They did it to avoid ammonia.

ㄴ Let’s Spin the Catapult: See the liver and BUN?

'Liver and BUN?'

I clicked on the lab results again.

[BUN 2mg/dL]

[AST 25U/L]

[ALT 30U/L]

An abnormally low BUN level and normal liver enzymes.

'They said the patient vomited a lot, right?'

Then they must be in a state of severe dehydration. Yet, prerenal azotemia didn't occur? Far from being high, the BUN is at a significantly lower level compared to a normal person. For this to be physiologically possible….

'The urea cycle must not be functioning at all.'

It made sense if the urea cycle function had completely stopped, failing to synthesize ammonia into urea. However, a fundamental question popped up in my mind.

Based on the evidence gathered so far, I knew it was a urea cycle disorder.

'But I don't know why this patient specifically has an OTC deficiency.'

ㄴ Korean Slave 1 (Male): But why specifically OTC deficiency?

ㄴ Latte is Mine: Gut feeling.

ㄴ Korean Slave 1 (Male): ????? A gut feeling???

ㄴ Latte is Mine: Hahaha, just kidding. Among urea cycle disorders, OTC deficiency is the most common X-linked genetic disease, so statistically, it has the highest probability. It could be a CPS1 deficiency, lol. But the treatment in the ER is similar anyway.

ㄴ Latte is Mine: Send out an orotic acid test.

An orotic acid test. That's something that needs to be sent to an external institution, and it takes an absolute eternity. As if reading my inner thoughts, another ghost chimed in with a comment.

ㄴ Hippocrates' Descendant: Check the amino acids at least, living doctor! Since the role of the OTC enzyme is to convert ornithine into citrulline, if it's an OTC deficiency, citrulline will be at rock bottom!

'Oh. The day has finally come where this grandpa is help… wait, no. That test takes just as long.'

Even so, since it was a test that ultimately had to be done for a definitive diagnosis, I jotted down the details on a post-it note.

Just then.

“The light reflex is too sluggish!”

At those words from Yoon Tae-hyun, I hurriedly rushed toward the bed.

'Let’s see….'

I pulled the penlight out of my pocket and shone it into the patient's eyes. Both were dilated to 4mm.

At that moment.

Beep-beep-beep-

Beep-beep-beep-

[BP 90/50]

[HR 115]

[RR 8]

[SpO2 82%]

The oxygen saturation suddenly began to plummet vertically.

“Give Etomidate 20 and Rocuronium 80! Quickly! A 7.5 tube and a blade 4 too!”

Suddenly, the patient fell into respiratory failure. Setting aside the differential diagnosis and everything else, I had to secure the airway first. I hurriedly pulled the equipment from the tray provided by the nurse and began the intubation.

“…Yes, fixed at 21cm. Ventilator setting is….”

Having hurriedly finished the rapid sequence intubation, I placed the stethoscope against the patient's lungs to check the breath sounds. Fortunately, it didn't go into the esophagus. The position was well-fixed too.

For now, the most urgent matter was to physically lower the intracranial pressure, which had swollen up due to the toxic ammonia. To allow the carbon dioxide to be expelled through the ventilator, it had to be set to induce hyperventilation.

“Put it on volume control mode, tidal volume 500ml, respiratory rate 18, FiO2 1.0, and PEEP 5, please.”

“Understood!”

Sigh. Since when did I become a person who memorizes ventilator settings, cardiac cath lab catheter types, and kidney dialysis values off the top of my head? Those damn ghosts. Just how much did they drill me?

'Anyway….'

UCD (*Urea Cycle Disorder) was confirmed.

Respiratory alkalosis caused by toxic ammonia striking the respiratory center of the brainstem, a BUN that came out lower than normal despite severe dehydration, and normal liver values. And decisively, a patient who fell into respiratory failure after the administration of valproic acid.

“This… Nurse Yoon?”

When I called the nurse, the nurse who was organizing something hurriedly raised her head and answered.

“Yes! Teacher Han! Why did you call?”

“Ah, draw some blood, please. Bring an ice bucket too.”

Ammonia is continuously produced at room temperature by enzymes inside red blood cells. In other words, to know the patient's exact condition, it must be stored in ice, and even then, if it doesn't arrive at the lab within 15 minutes, it is prone to false positives. That’s why we had to be even more cautious.

“We’ll send a serum amino acid test too. This is probably a special test, so it'll take a while.”

“Amino acids too?”

“Yes.”

In the distance, I could also see Choi Hyun-jin from Neurology making a phone call somewhere. It was probably a Neurology staff member or the Internal Medicine on-duty doctor.

“Tae-hyun.”

When I called Yoon Tae-hyun, who was organizing charts of another patient from a nursing home in the distance, he turned toward me and answered.

“Yes, Teacher. Did you call?”

“Let’s put in a consult to Endocrinology and Nephrology.”

Since it was a metabolic disease, the department primarily responsible for overall treatment would be Endocrinology and Metabolism. And because dialysis was needed to directly and physically wash away the massive amounts of ammonia mixed in the blood, Nephrology was called too.

“We don’t need to put one in for Gastroenterology… right?”

“Have you still not given up on hepatic encephalopathy?”

I told you the liver values are normal. Why on earth Gastroenterology?

“Ah, sorry. I’ll put the consults in right away.”

“Do that.”

I focused my gaze on the computer screen again and began to determine the patient's treatment direction.

'Hmm… then how….'

I turned my head and turned on the window in the void.

Flash-

[Dead Medic Gallery]

Guys helphelp regarding the urea-whatever patient

Author: Korean Slave 1 (Male)

How do I treat them?

[Comments]

Latte is Mine: Should I seriously beat you up?

No, why? What's wrong with the way I talk? Didn't I go in with the lowest posture possible?

ㄴ Korean Slave 1 (Male): Cut me some slack.

ㄴ Hippocrates' Descendant: Ghost Latte, seeing the sincerity of the living doctor, there seems to be room for consideration! Living doctor, please be careful not to use such a strange tone as well!

At Grandpa Hippo's shield, Latte finally threw up his hands in defeat.

ㄴ Latte is Mine: Insert a CVC.

ㄴ Korean Slave 1 (Male): Why?

ㄴ Latte is Mine: You need to give an ammonia scavenger.

At those words, I raised my head and looked back at Yoon Tae-hyun.

“?”

To Yoon Tae-hyun, who was staring at me with a look full of question marks, I gave a simple instruction. Yes. Simple.

“Could you catch a C-line? For that patient?”

“A C-line?”

Was he flustered because I suddenly told him to catch a central venous catheter?

“We have to give an ammonia scavenger anyway. Hurry.”

“Ah, yes!”

With that, I opened the window in the void again.

ㄴ Korean Slave 1 (Male): (Picture) Patient weight and height.

ㄴ Korean Slave 1 (Male): Calculate it 'for me'.

Haha. You guys are calculation slaves, you fools.

Typical drugs are calculated per body weight, but these drugs require complex calculations using the body surface area formula, which is quite a headache and difficult. So, toss it to the ghost.

ㄴ Latte is Mine: D10W 165ml per hour. Intralipid 20% 60ml per hour.

ㄴ Latte is Mine: 1750ml D10W, 101.75ml Ammonul. Go.

'Why is the calculation so complicated?'

ㄴ Korean Slave 1 (Male): Do we absolutely have to go that way?

ㄴ Latte is Mine: If you don't like it, calculate it yourself.

Ugh. There's nothing I can do.

Anyway, Endocrinology or the specialized department will confirm the order one more time later, and until then, we just need to prepare. However, the point to be cautious about as an emergency medicine physician in this process was….

'Because iatrogenic hyperglycemia could occur.'

Infusing glucose can cause high blood sugar. However, the glucose infusion rate must not be reduced arbitrarily because of that. If glucose infusion is reduced, insulin secretion decreases while glucagon increases, and if that happens, muscle proteins begin to break down, creating what?

Exactly, ammonia is generated again. In other words, it goes right back to square one.

ㄴ Korean Slave 1 (Male): If hyperglycemia comes, control blood sugar while running an insulin infusion. If it's right?

At my question, Old Man Latte affirmed my opinion.

ㄴ Latte is Mine: Yep.

Mes of the God (Male): Boo, I don't know what you're talking about.

Ignore that old man.

With that, I set up the medications in advance.

“…So the ER entered all these orders first?”

Endocrinology fellow Jeon Soo-hyun asked with a look of disbelief.

At that question, I quietly sat on the chair, clicking the computer, and replied.

“Yes. Please confirm the order.”