How to rescue a patient whose body was soaked by 50℃ hot phenol?

Author’s Note: 31.5 tons of pure phenol, a hazardous chemicals car, two drivers.

In 2018, due to an operation error, the tank valve was not aligned with the unloading valve, and more than 30 tons of hot phenol was sprayed from a thick pipe with a diameter of more than 50 cm like a high-pressure water gun .

In just a few seconds, Lao Luo’s whole body was soaked with more than ten kilograms of hot phenol, and a piercing pain hit his body. In less than ten minutes, due to the central toxicity, Lao Luo’s eyes darkened and he passed out.

Foreign literature reports that the fatality rate of acute phenol poisoning is as high as 50%, and domestic reports are 30%. Lao Luo was exposed to phenol concentration of up to 990g/L, and the total burn area exceeded 40% TBSA, which soon led to poisoning and renal damage, and the attack was ferocious. There are few reports of successful treatment in such cases.

In the recollections of several doctors, they have never seen a case of such a large area of ​​burns by toxic substances before…

The author of this article: Hu Xing

Deputy Chief Physician, Department of Burn and Wound Repair, Second Affiliated Hospital of Zhejiang University School of Medicine

Plug the phenol leak with your body

One ​​day in 2018, Lao Luo, who has nearly 40 years of full-time experience in transporting hazardous chemicals, and his old partner, a 32-ton phenol truck dedicated to transporting hazardous chemicals, because of a transshipment Tasks become extraordinarily busy.

At 7:00 this morning, they loaded 31.5 tons of pure phenol from a port on the Yangtze River and set off for a factory in northern Zhejiang, 200 kilometers away.

Phenol, also known as carbolic acid, has a melting point of 43°C. It is a colorless needle-like crystal with a special odor at room temperature. It has a wide range of industrial uses. It is an important raw material for medicines and medicines such as aspirin. It can also be used to sterilize surgical instruments and excreta, skin sterilization, antipruritic and otitis media.

Image source: Figure Worm Creative

However, high-purity phenol is a highly toxic substance: it has a strong corrosive effect on the skin and mucous membranes, and can inhibit the central nervous system or damage the functions of important organs such as the liver, lungs, digestive tract, and kidneys. . Absorption by burnt skin causes acute renal failure after a certain incubation period.

For this reason, the transportation of phenol requires extremely high standards: in addition to experienced full-time drivers like Lao Luo, special transport vehicles are also fully armed: In order to prevent phenol from being transported in Crystallization is blocked at room temperature, and the tank body and valve pipeline have special heating wires to keep the phenol above the melting point; from the tank body to the unloading, multiple sealing valves are used to prevent leakage. One of the most important tank valves can be opened and closed with one key from the cab.

At ten o’clock in the morning, Lao Luo arrived at the unloading area of ​​the factory. According to the operating procedures, he needs to heat the unloading valve and the factory pipeline to above 50°C to ensure that the phenol remains liquid during infusion; then connect the two, and then notify his companion to open the tank valve on the car, and the preheated phenol will will flow out.

Just as he was about to connect the discharge valve to the piping, the accident happened.

Perhaps it was due to the fatigue of the continuous rotation. His companion was negligent and directly opened the tank valve without checking the connection status of the unloading pipeline. More than 30 tons of phenol are sprayed from a thick pipe with a diameter of more than 50 centimeters like a high-pressure water gun.

Image source: Figure Worm Creative

Being too late to think about it, Lao Luo subconsciously flew up and rushed up, trying to use his own body to block the “hole of the gun”. Years of work experience and knowledge of phenol told him that the leakage of phenol must be stopped immediately – a large amount of leaked phenol volatilizes, and the high concentration of steam will cause extremely tragic mass incidents in this densely populated factory area.

In just a few seconds, Lao Luo’s whole body was soaked with more than ten kilograms of hot phenol, and a piercing pain hit his body. He shouted to his companions to turn off the tank valve, and while rushing towards the spray point in the unloading area, he quickly took off his protective clothing and gas mask, and immediately began to rinse with plenty of water. At the same time, the workers in the factory also brought phenol. Contaminated with special-effect detergency agent, Diphtrine, for decontamination.

However, the amount of phenol contamination was so great that within ten minutes, due to the effect of central toxicity, Lao Luo’s eyes darkened and he passed out.

Over speeding, the director ran 8 red lights in a row

Image source: The Second Academy of Zhejiang University, Professor Han’s team

At 2:00 p.m., Professor Han Chunmao, director of the Burn and Wound Repair Department of the Second Hospital of Zhejiang University and director of the Zhejiang Provincial Burn Treatment Technical Guidance Center, who had just finished the lunch break, received the original Hangzhou Jianggan District People’s Hospital (Jianqiao Hospital) The emergency call from Director Wu Jiyan, the head of the burn department and vice president: “Professor Han, please consult urgently. There is a patient with extremely severe phenol burns who is in a coma. Please come to support as soon as possible!”

Injury is an order, Director Han immediately put down his work and ran downstairs, standing on the side of the road beckoning to stop the car. After he jumped into the taxi, he continued to make calls to inform Director Wu of the patient’s treatment points:

-Rinse the wound with plenty of alcohol and normal saline to remove the contaminated phenol residue and block further absorption;

-Accelerate fluid replacement to promote urine excretion, pay close attention to deep venous pressure and renal function;

-When necessary, tracheostomy is required to avoid respiratory depression.

Half an hour later, when he arrived at Jianqiao Hospital, he found that the patient’s condition was more serious than expected: due to the absorption of a large amount of phenol, the patient quickly developed central symptoms: sometimes unconscious, sometimes unconscious Constantly restless, this is the performance of alternating inhibition and excitement.

However, after indwelling catheterization to remove 500 ml of the patient’s pre-injury urine, two hours later, the urine bag was still empty, indicating that the patient developed severe acute kidney disease functional failure and the most severe anuria.

Image source: Figure Worm Creative (not this case)

Since phenol cannot be detoxified by the liver, its only excretion channel is through the kidneys and excreted in the urine, and acute renal failure is equivalent to blocking this only way of life, and for detoxification A large amount of infused liquid accumulates in the body because there is no way to discharge it, which will cause a huge load on the heart’s pumping blood, the core of the circulatory system. The patient is clearly in a bad way at the moment.

Professor Han knows that phenol is a highly toxic cytoplasmic poison, which can not only burn the skin and mucous membranes, but also be absorbed by the body through the skin and mucous membranes, causing systemic poisoning and damage to multiple organ functions. . Early acute kidney injury (AKI) is a common complication of phenol burns.

Foreign literature reports that the fatality rate of acute phenol poisoning is as high as 50%, and domestic reports are 30%. Lao Luo’s exposure to phenol concentration was as high as 990g/L, and the total burn area exceeded 40% TBSA, which soon led to poisoning and renal damage.

Minimizing the absorption of phenol and accelerating the excretion of phenol as soon as possible is the key to treatment.

At present, the key to the successful rescue of phenol burns is to promote the excretion of phenol from the body through the adsorption and filtration principles of blood purification on the basis of conventional treatment of burns, and to correct electrolyte and acid-base balance disorders. Prevent and treat azotemia, control fluid intake and output, clear inflammatory mediators, restore immune balance, and provide conditions for other treatments. To save this patient, hemodialysis must be used as soon as possible.

Image source: Figure Worm Creative (not this case)

Kejianqiao Hospital does not have such treatment conditions, and the patient must be transferred to the Jiefang Road District of the Second Hospital of Zhejiang University as soon as possible for further treatment.

Arrange the pre-transfer treatment, contact the transfer ambulance, instruct the doctor on duty that day, Pan Xuanliang, to arrange the registration and hospitalization procedures for the patient in advance, and contact the head of the Nephrology Department and Blood Purification Team in our hospital by phone. Director Hu Ying informed the equipment department and the patient chief physician Chen Guoxian to prepare the follow-up CRRT equipment for the patient.

At 5:00 p.m., the ambulance pulled out of Jianqiao Hospital. At the peak of the weekday evening, in order to save time, 57-year-old Professor Han turned into an “old driver” and personally sat in the co-pilot to assist the driver to run all the way.

Screaming sirens, roaring engines, 8 red lights along the way, almost all of them in a row. Conventional roads, expressways, elevated roads, they speeded all the way, and social vehicles gave way. 13.7 kilometers in just 22 minutes. (Note: Article 53 of the “Road Traffic Safety Law of the People’s Republic of China” stipulates that when police cars, fire engines, ambulances, and engineering rescue vehicles perform emergency tasks, sirens and sign lamps may be used; on the premise of ensuring safety , not restricted by the driving route, driving direction, driving speed and signal lights, other vehicles and pedestrians should give way.)

Because of the advance report, the 120 ambulance did not go through the emergency procedures and came directly to the door of the hemodialysis room on the first floor of Building 2.

First battle: Patient BP 200mmHg

While Professor Han was dragging the patient all the way, Dr. Hu Ying from the Nephrology Department and Blood Purification Team was already on guard. After receiving Professor Han’s call for help, Dr. Hu Ying immediately summoned the doctor Zhu Lina, the nurse Zhou Susu, Luo Shiying, Wang Fang, etc. to prepare the machine and bed.

Photo source: The Second Academy of Zhejiang University, Director Hu Ying’s team

In the recollections of several doctors who received them, no one had ever encountered such a large area of ​​burns by toxic substances before. First, such substances are hazardous chemicals, which are basically inaccessible to ordinary people; secondly, this is also an uncommon production accident.

Therefore, the experience can only be pushed back to the dimension of “physiology and biochemistry”. Different from small molecules such as creatinine, phenol is a macromolecular organic compound, its water solubility is not strong at room temperature, and its removal efficiency is very low through simple hemodialysis (that is, material exchange through a semipermeable membrane using osmotic pressure).

Therefore, in order to more effectively remove phenol from the blood, it is necessary to use hemoperfusion technology (HP) on the basis of hemodialysis. Simply put, the drawn blood is passed through a filter device similar to activated carbon to absorb macromolecular toxins, which can improve their removal efficiency hundreds of times.

At 5:30, as soon as the patient enters the hemodialysis room, the intensive work begins immediately, the deep vein catheter is removed, the dialysis catheter is punctured, the pipeline is connected, and the machine is operated. The gurgling blood was drawn out through the femoral vein catheter, and after being purified by the hemodialysis device, it flowed back into Lao Luo’s body through another catheter.

The special point is that, because the excessive exudation of the burned body surface will cause insufficient renal perfusion, the patient needs to be ultrafiltered during the blood purification process, and fluid infusion is also given at the same time. and furosemide.

In less than half an hour, a miracle that excited everyone happened. Lao Luo actually opened his eyes and regained consciousness. He tried his best to look at the wall clock on the wall. The time pointed to 18:00. The whole thing—he was in a coma for 8 hours. At this time, he was completely unaware of what all the medical staff of our two hospitals and three teams had experienced.

However, it is not time for us to relax.

The upper limit of blood pressure for the average adult is about 120 millimeters of mercury (mmhg), and due to acute renal failure and fluid retention, etc., the patient’s blood pressure on admission is as high as 200 mmhg, which is sufficient The risk level of inducing cardiovascular and cerebrovascular accidents.

Intravenous yanidine was given immediately to control blood pressure. After half an hour of blood purification treatment, blood pressure dropped significantly, and the dose of yanidine was reduced, and the fluid replacement was accelerated and the ultrafiltration rate was reduced according to routine steps, and the hemodynamics soon became stable.

However, after the high blood pressure was quickly corrected, the patient experienced transient hypotension. Dr. Zhu immediately adjusted the parameters of the hemodialysis machine to ensure that his vital signs remained stable during the treatment.

At 8 p.m., 2 hours after hemodialysis, fresh and clear urine slowly flowed out from Lao Luo’s urine bag like spring water, and everyone present let out a sigh of relief – This means that his acute renal failure has been initially reversed.

Lao Luo’s Rebirth

Four hours after hemodialysis, Lao Luo was awake and his vital signs were stable. At this time, the filter membrane of the hemodialysis machine had reached the end of its life. He was transferred to the ward of the Burn and Wound Repair Department. , and handed over to the team of Director Chen Guoxian for more lasting continuous renal replacement therapy (CRRT) treatment at the bedside.

Compared to traditional dialysis equipment, which has powerful dehydration and detoxification functions and works quickly, but lasts less than 4 hours, the biggest advantage of CRRT is that it has a much longer working cycle, its filter It can withstand a working cycle of up to 8 to 24 hours or even longer to achieve long-term protection of kidney function and body water and electrolyte balance. Because hemofiltration is performed continuously and slowly, CRRT can be closer to the filtration function of the glomerulus under physiological conditions than conventional hemofiltration and hemodialysis, and has less impact on human hemodynamics and renal perfusion.

Source: The Second Academy of Zhejiang University

Therefore, the successful experience reported in domestic and foreign literatures on phenol treatment is to combine the advantages of the two and combine 4-hour hemodialysis + perfusion adsorption and 12-hour CRRT into one. Purification cycle, repeated many times, in order to completely remove phenol from the body and correct acute renal damage to the greatest extent.

What makes the chief physicians Chen Guoxian and Pan Xuanliang feel amazing is that Lao Luo, who has only completed one purification cycle, not only has stable vital signs, clear consciousness, clear thinking, and no sequelae of brain damage. The performance, urine output and various liver and kidney function indicators have gradually returned to normal levels, which is a rare situation that has not been reported in domestic and foreign literature.

Therefore, Director Chen’s team boldly stopped the dialysis treatment for the patient after only one cycle of treatment. In the follow-up close review, Lao Luo’s various organ indicators did not deteriorate or rebound again.

Of course, in addition to acute renal failure, burn treatment is also scientifically underway.

The team did not perform the surgery directly in the first place. Most of Lao Luo’s phenol burn wounds were second-degree wounds, and previous literature experience is that most of them can heal on their own after proper treatment.

Photo source: The Second Academy of Zhejiang University

Lao Luo is lucky. Because they have received the corresponding first aid training, the work unit has a relatively effective first aid plan. After the injury, the contaminated clothing was removed and washed with clean water, and washed with diphtidine. Emergency medical treatment was given immediately after arriving at the hospital. Ethanol wiping, a series of first aid measures, not only removed the source of pollution to the maximum extent and reduced the absorption of phenol, but also laid a solid foundation for subsequent success. (Note: Both domestic and foreign guidelines recommend removing chemicals immediately after chemical burns and flushing with plenty of running water to reduce continuous damage to the skin and absorption of chemicals. In the selection of specific detergents, the International Burn Society recommends polyethylene Glycol, isopropanol or glycerol, domestic guidelines recommend ethanol. Some researchers have compared the animal experiments and found that the decontamination effect of 75% ethanol and polyethylene glycol 400 on phenol is similar, and the decontamination effect of diphtrine works best.)

Under the careful dressing care of Director Chen and Dr. Pan, Lao Luo’s chemical burn wounds on his body gradually recovered and healed. 29 days later, Lao Luo got up and went to the ground, recovered and was discharged from the hospital.

The author’s statement: Just like Luo Yong and Gan Yu who stood up during the earthquake, faced with the leakage of more than 30 tons of highly toxic phenol, Lao Luo’s first reaction was to sacrifice his life” “Gang the bullet” behavior. It is for this reason that our medical staff also joined hands to provide the most timely and best treatment for this civilian hero who stepped forward to save countless lives, enabling him to recover safely. The love that goes both ways is the most moving Chinese story in this era.

Planner: carollero|Producer: gyouza

The title map and poster source: Figure Worm Creative

Acknowledgments: The Second Affiliated Hospital of Zhejiang University School of Medicine

Lilac Garden is a professional platform for medical practitioners, with the mission of “helping Chinese doctors”. Download the “Lilac Garden App” to discuss cases with peers, study open classes online, use clinical decision-making tools such as medication assistants, and find reliable medical positions in Lilac Talents.