Seeking Truth with a Sword

In a high-altitude environment, atmospheric and partial pressures of oxygen gradually decrease. The supply of oxygen is hindered, leading to an increase in anaerobic metabolism in brain cells and a decrease in ATP production. The dysfunction of sodium ion pumps in brain cell membranes causes retention of sodium and water within the cells, leading to cytotoxic cerebral edema. If not rescued in time, it could turn into a vicious cycle of *brain hypoxia, cerebral edema, increased intracranial pressure, cerebral circulation disorder, difficulty in oxygen diffusion, and further brain hypoxia*.

Li Ang thought silently. High-altitude cerebral edema is common among those who rapidly ascend to altitudes above 4,000 meters. Initially, it presents with severe headaches, vomiting, palpitations, shortness of breath, and slow reactions, and can progress to coma if severe.

The elevation of Chang'an is around 400 to 700 meters, while Qinling Taibai Mountain is indeed about 3,700 meters high. However, the two places are two hundred li apart. It's impossible that the tattooed Han man climbed Taibai Mountain, developed high-altitude sickness, and then was transported back here by a galloping horse.

If it's not a high mountain or plateau, then it must be a low-pressure, low-oxygen environment with similar conditions.

For example, an artificially created low-pressure chamber, or being carried rapidly into the air using a Flying Sword—this could also trigger high-altitude cerebral edema.

However, Pu Liuxuan once mentioned that high above the surface, the Heaven and Earth Gang Wind existed, constantly tearing and ravaging without a moment's pause. The higher one goes, the more dangerous the Heaven and Earth Gang Wind becomes.

Even armor made of Fine Steel, if thrown into the upper Gang Wind Layer, would be shredded to pulp in the blink of an eye.

The tattooed Han man's body showed no obvious external injuries. It was likely not caused by rapid ascension.

An Alien? Magic? Or something else...

After pondering for a moment, Li Ang did not delve deeper—Jiao Cheng and the others remained silent, clearly hiding secrets and unwilling to answer.

"The ice is here!"

Di Wu, accompanied by others, brought over blocks of ice and a wooden barrel.

Soon after, the subordinates who went to the East Market to buy kelp and Plaster returned.

"Break the large ice blocks into pieces, put them in bags, and cover his body and head."

Li Ang commanded, directing Di Wu and the others to cover the comatose man's body with ice.

This would reduce his cerebral blood flow, lower his brain's metabolic rate, promote the recovery of injured brain cells, and alleviate the vicious cycle caused by hypoxia.

The treatment for high-altitude cerebral edema first involves lowering the altitude, bed rest, and ensuring an unobstructed airway, followed by cryotherapy and oxygen inhalation. High-concentration, high-flow oxygen inhalation can correct the state of brain hypoxia and break the vicious cycle.

Li Ang muttered silently. The problem is, right now there is no high-concentration oxygen. Calcium Peroxide, Hydrogen Peroxide, and Manganese Dioxide... none could be prepared quickly, and the electrolysis of water would require a continuous, stable supply of electricity.

The Electric Light Talisman and the Thunder Strike Technique are both talismans and Magic of the Cloud Patrol Realm, but they seemed too unstable. By the time enough high-concentration oxygen could be produced, it would be too late.

Only one method remains now: using medication to lower intracranial pressure and improve cerebral circulation.

Li Ang looked towards the large amount of kelp Jiao Cheng's subordinates had brought back.

This kelp was dried, and its surface had a layer that looked a bit like mold—a white, frost-like substance.

The white frost that crystallizes on the surface of dried kelp is actually Glycerol—an isomer of sorbitol. Glycerol tastes similar to sucrose. It is one of the most commonly used medications in the emergency treatment of brain disorders. Upon injection, it can quickly increase plasma osmotic pressure, causing water from the tissues to enter the bloodstream, thereby reducing intracranial and intraocular pressure and alleviating cerebral edema.

Information about Glycerol flashed through Li Ang's mind. He instructed Jiao Cheng's subordinates to cover a wooden barrel with multiple layers of washed gauze. Then, they washed the kelp with water, scraped off the white frost, and poured the water containing the dissolved frost into the barrel.

The gauze served as the first layer of filtration, removing sand and dirt from the surface of the kelp.

The next step was flocculation.

Li Ang peeled back the covering gauze, wrapped Plaster around a stick, and then stirred it into the barrel.

The best flocculating agents would be chitosan or carboxymethyl chitosan. Failing that, Aluminum Sulfate or Iron Sulfate would also work, as they can adsorb and separate colloids. Plaster... it will have to do.

"That should do it."

Li Ang stirred for over seven minutes. Seeing the solution gradually settle and clarify, he stopped.

A few minutes later, the turbidity settled to the bottom, and the solution in the barrel stilled and stratified.

Li Ang fetched a ceramic bottle and filled it with the clear liquid from the top layer.

The standard treatment for cerebral edema is a 20% intravenous drip of Glycerol.

However, the Glycerol concentration here might only be about 2% to 2.5%, far below the concentration and hygienic standards required for an IV. Quantity would have to make up for quality; drinking it should suffice.

Li Ang had someone pour the solution from the bottle into the comatose man's mouth. He also had them continue to replace the ice packs on the man's body, and then he stood by to wait.

After an unknown period, the tattooed man finally opened his eyes. He looked around weakly, trying to remove the cold ice packs covering him.

Seeing that the man had regained consciousness and his cerebral edema was temporarily alleviated, Li Ang turned to Jiao Cheng and said indifferently, "He's awake. Keep him lying flat for seven days. If his symptoms worsen, feed him the filtered kelp soaking liquid using the same method I just used. Don't let him drink too much, or he could still die. Now, it's time you kept your promise."

The comatose man was one of Jiao Cheng's lackeys. Issues such as cerebral edema sequelae, post-recovery complications, and diarrhea caused by oral Glycerol were completely outside Li Ang's concerns.

Jiao Cheng shifted his gaze from the comatose man and nodded toward Li Ang. The bald Di Wu then led Li Ang out of the room and upstairs.

"All of you, leave."

After Li Ang left, Jiao Cheng motioned for everyone in the room to leave, including the two Sword Masters. He then walked over to the tattooed man's sickbed, firmly grasped the man's hand, his own eyes sparkling as he whispered, "Third Son, tell me, what did you see in the Sword Immortal Tomb beneath the Chang'an Ghost Market..."

"Risheng..."

"Let's talk outside."

In an upstairs room, Li Ang raised his hand to stop Song Shaoyuan. Led by Di Wu, he, along with You Douzhi, left the building and met Wu Shiqi, who had been waiting in the courtyard.

"Mr. Li."

Upon seeing Li Ang, Wu Shiqi immediately rose from the rock he was sitting on and bowed even more respectfully.

He wasn't surprised that Li Ang had managed to leave the building safely. However, he was astonished that Li Ang had been able to bring both Song Shaoyuan and You Douzhi with him. He knew You Xiao was Lotus House's cash cow, and her attempt to escape had certainly touched a raw nerve with Jiao Cheng.

Li Ang... had actually managed to leave unharmed with both of them...

Li Ang ignored Wu Shiqi's bewildered amazement and bowed. "Brother Wu, thank you for your help this time."

"Ah—"

Wu Shiqi snapped out of his daze and hurriedly returned the bow, repeatedly saying, "Not at all, not at all. I merely led the way."

"Mr. Li, we're even now."

Di Wu looked at Li Ang, a flicker in his eyes. The implication was very clear: nothing had happened in the loft today.

"Alright," Li Ang replied. "I'll bring the rest of the money later, and we'll be all settled."

Li Ang nodded calmly and led the trio out of Pingkang Square.

Wu Shiqi left first, citing official business of the Bad People.

Song Shaoyuan and You Douzhi stood before the Pingkang Square wall, basking in the warm sunlight that enveloped them. The despair and helplessness they had felt inside the building just an hour ago now seemed like a distant dream.

As if from another lifetime.

"Risheng," Song Shaoyuan turned to Li Ang, bowed deeply, and sincerely expressed his gratitude, "This time... I've troubled you. When I get back, I'll go to the bank…"

"There's no need for such words between us brothers," Li Ang casually waved his hand. "Even for Aunt Song's sake, I couldn't just leave you, could I?" He glanced at You Xiao, who was standing beside Song Shaoyuan. "You Douzhi, I've spoken with Jiao Cheng. You're no longer with Lotus House. You can move out. After a while, once you're fully released from servitude, you can arrange for someone to retrieve your personal belongings from Lotus House. If there are any personal maids you wish to redeem, that can also be discussed."

You Douzhi thanked Li Ang profusely. After Li Ang dissuaded her from further thanks, she stepped back half a pace and leaned gently against Song Shaoyuan, like a small bird seeking refuge.

The love in their gazes was so intense it seemed to melt each other.

Aunt Song, I was wrong. Chang'an truly is a demonic den that devours people whole, bones and all...

Li Ang looked at Song Shaoyuan, who was completely captivated by love, and shook his head helplessly. He called for a carriage to take the couple back to the West Market to inform Yang Yu and their other classmates still waiting there that everything had been resolved. This would also reassure Chai Cuiqiao at home not to worry.

Li Ang himself took the horse's reins and strolled leisurely westward, his mind casually pondering various matters.

The modern industrial method of extracting Glycerol from kelp involves numerous complex steps, including soaking, purification, acidification, iodine extraction, evaporation, concentration, cooling for crystallization, centrifugal separation, and drying.

The Glycerol solution he had just extracted from the kelp soak was merely a crude concoction made under primitive conditions.

Modern medicine is built upon the foundations of modern science and industry.

Glycerol was already so difficult to acquire; other emergency medications like adrenaline, Cedilanid, sodium nitroprusside, and lidocaine were even more challenging to obtain...

The silver-bell-like laughter of children interrupted Li Ang's contemplation. In an open field, a group of children, around seven or eight years old, were whipping different colored spinning tops with ropes, making them collide.

Spinning top battles, huh?

A slight smile touched Li Ang's lips as his mind wandered to the childish act of secretly adding weights to spinning tops to enhance their destructive power in battles.

Wait... Spinning tops… Centrifugal force?!

A sudden insight flashed before Li Ang's eyes. He had a sudden, powerful realization.

There was hope for Duke Yan's illness!