Text | Wang Yan ◆ Source | Drunken Magnolia

"Surgeries vary in size, and anesthesia does not vary in size." This is a saying often said in the industry. Even if it is a minor surgery, the anesthesiologist must make a fuss out of a molehill and be meticulous! Because anesthesia crises often occur very suddenly or even without warning, the patient's vital indicators must be closely monitored in order to detect problems in time and handle them quickly.

01

Calm

Recently, a 49-year-old female patient was scheduled to undergo hysteroscopy under general anesthesia due to "cervical polyps" . The patient was in good health and had normal cardiopulmonary function, and no obvious abnormalities were found in the preoperative examination.

In the past, "cesarean section" was performed under spinal anesthesia and "ectopic pregnancy surgery" was performed under general anesthesia, and the anesthesia operation went smoothly. (Well, this is an extremely ordinary case of anesthesia: the pre-anesthesia assessment is ASA I level, both surgery and anesthesia are low-risk, and the probability of perioperative cardiovascular events is <1%)

Patient After entering the room, routine monitoring of vital signs was established, intravenous access was opened, and after three-party verification, conventional anesthetic drugs sufentanil, etomidate, and cisatracurium were used for anesthesia induction, and then a laryngeal mask was placed and mechanical ventilation was performed.

All procedures were in order. However, just 3 minutes after induction, the patient's blood pressure dropped rapidly from 120/80 to 60/40mmHg (non-invasive cuff pressure), the heart rate gradually accelerated to 110 beats/min, and the oxygen saturation waveform was inconsistent. It showed that PetCO 2 dropped. After giving 4 or 8ug of norepinephrine, the blood pressure did not rise but dropped further. Wang Yan, the second-line anesthesia doctor, immediately realized that this was by no means ordinary post-induction hypotension. The patient was most likely to have serious symptoms. Anaphylaxis!

An allergic reaction, simply put, is a series of "cascade" systemic reactions caused by a sharp increase in capillary permeability after the human body is exposed to a certain substance.

We know about food allergies, pollen allergies, etc., but many people don’t know that allergies can also occur during anesthesia. According to reports, the incidence of perioperative allergic reactions is one to one in 20,000 to 1 in 10,000. About half of patients develop symptoms within 5 minutes of exposure to the allergen, and only 10% of patients develop symptoms half an hour later.

Relatively mild cases only show skin redness and maculopapular rash; in more serious cases, in addition to skin manifestations, there will be rapid heartbeat, dyspnea and gastrointestinal symptoms; in more serious cases, patients will have heart disease and gastrointestinal symptoms. The blood vessel function is severely disrupted (blood pressure cannot be measured, heart rate is increased), bronchial spasm occurs, which is life-threatening; in some cases, the heartbeat stops immediately.

No matter what substance you are exposed to or the dose you are exposed to, an allergic reaction is an "all or nothing" matter. Only the severity varies. Once the circulatory system is endangered, it is a severe anaphylactic shock.

02

Storm

The patient’s blood pressure continues to drop, and it is very likely that cardiac arrest will occur at any time! Dr. Wang immediately gave 100ug and 200ug of epinephrine intravenously and activated the emergency call system of the anesthesiology department at the same time!

The director of the logistics army received a call while checking patients in the PACU (20 meters away from the 13th operating room where the incident occurred), and immediately ran to the operating room with Dr. Bing Hailong. After a brief communication with Dr. Wang, Director Chu issued an anaphylactic shock level IV (the highest level) rescue instruction and continued to conduct ABCDEF process assessment!

Further deploy 3 anesthesiologists and nurses to arrive at the scene urgently, and at the same time carry out division of labor and clear instructions:

1 person to establish invasive arterial pressure monitoring

1 person Establish central venous access

One person continued to establish peripheral venous access

One person changed the tracheal intubation for mechanical ventilation

One person underwent intermittent TTE monitoring. After intubation Change to TEE monitoring. (One person really can't bear it during the rescue, so calling for help in time is the best way)

Give accessory kidney 200ug\500ug\1mg intermittently until the accessory kidney is 3mg intravenously, 2mg accessory kidney is injected by pump, and the accessory kidney is injected by pump. When taking 2 mg of A and 2000 ml of fluid, the blood pressure can barely maintain 80/50 mmHg. TEE shows an obvious kiss sign, indicating insufficient volume. Continue to inject fluid to 5000 ml + balanced salt solution (crystalloid) (within 1.5 hours).

During first aid, 20U was given to the pituitary gland, followed by pumping 4U/h, and intravenous injection of Milan. During this period, blood gas analysis was performed to actively correct electrolyte imbalance and acid-base balance. During a series of intensive rescue measures, the patient's eyelids, lips, and arms gradually developed obvious edema, and the skin on his chest and thighs developed wheal-like rash changes, which further confirmed the correctness of the diagnosis of anaphylactic shock and the rescue measures.

After 3 hours of rescue, the blood pressure rose, and the dosage of vasoactive drugs was gradually reduced (6 accessory kidneys were used during the rescue). The patient's consciousness recovered, and the tracheal tube was pulled out after all vital signs were stabilized. After half an hour of observation, he was sent to the ICU.

03

Return to peace

(The discipline of anesthesiology has grown relatively late, but the work requirements are very high. We bear the responsibility that we should not be wise and steady at this age... )

This is a typical case of perioperative allergic reaction caused by anesthetic drugs. It is like an avalanche without warning. In just a few minutes, life has a "cascading" collapse. Fortunately, the rescue was timely. If the anesthesiologist's judgment and treatment were a little late, the consequences would be disastrous.

Therefore, being an anesthesiologist is a high-risk profession, and it is really not just a matter of "getting an injection". If surgeons are dancers on the tip of a knife, then anesthesiologists are even more dancers on the tip of a needle!

04

In summary of the above complaints

At the morning meeting, Director Chu gave a brief summary of the rescued patient in this case: The patient was a middle-aged female, who had been in good health. A minor gynecological surgery was planned. Severe anaphylactic shock occurred during the induction of general anesthesia. According to the perioperative allergy classification, this patient was grade III: hypotension and skin and mucosal symptoms that threatened the patient's life. The diagnosis is basically clear, the treatment is timely, and the patient's prognosis is better!

The successful rescue experience of this patient:

The anesthesiologist made an accurate prediction (Grade III allergy) and made a decisive decision (timely Activate the emergency call system) - This is very important. Similar to CPR at the scene, call 120 for help first, and then rescue! Buy valuable time for the emergency expert team to arrive! ;

The rescue is organized in an orderly manner and the division of labor is clear: an emergency response team with the department director as the leader is quickly established on site, the human and material resources of the department are mobilized to initiate the first aid procedures, and the division of labor is carried out according to the ABCDEF process to ensure that all implementation operations are accurate and effective. The treatment efficiency is greatly improved. (Members of the emergency expert team of the department: department director, chief resident, cardiac anesthesia team, and nerve block team. All anesthesiologists above the attending level serve as department directors during work hours. When an emergency occurs, the chief resident is responsible for mobilizing members of the emergency team. The team members must be mobilized as soon as possible. Arrive at the emergency scene without delay, and unconditionally obey the leader's arrangement of first aid roles and division of labor for rescue);

For grade III-IV allergies, intravenous administration of accessory kidneys as soon as possible, establishment of sufficient intravenous access as soon as possible, and rapid infusion of crystalline rehydration , up to 2-3L, other measures are auxiliary measures;

For life-threatening hypoxia and hypotension, use bedside ultrasound as early as possible and implement the THIRD process:

(This example The patient underwent TTE/TEE monitoring in a timely manner and was given guided fluid replenishment, which improved the success rate of treatment)

For any situation that threatens the patient's life during the operation, the patient's condition should be communicated with the family member in a timely manner and an informed consent form should be signed. Communicate with superiors (including department directors, medical departments, and even hospital leaders) in a timely manner. (The patient in this case communicated with the patient’s family about the changes in his condition three times during the rescue process, signed informed consent, and reported to the hospital administrative department).

Small class on allergic reactions

◆What are the manifestations of perioperative allergic reactions?

Allergy is the body’s immune response to foreign substances (drugs, food, bacteria, viruses, etc.). It is actually a protective effect on the body. Most allergic reactions that occur during anesthesia will cause skin and mucous membrane symptoms, and in severe cases, cardiovascular system manifestations, bronchospasm, etc. will occur.

According to the severity of allergic reaction, its clinical manifestations are divided into 4 levels:

◆Why do allergies occur during surgical anesthesia?

General anesthesia is currently one of the most commonly used anesthesia methods, requiring the use of at least three basic drugs: sedatives, analgesics, and muscle relaxants;

Intraoperative fluid infusion , antibiotics, and infusion of plasma, albumin, etc. when necessary;

Surgery may also use anti-adhesion drugs, hemostatic drugs, implantation of bone cement, prosthesis, etc.

Patients are exposed to and infused with multiple potentially allergic substances at the same time during the perianesthesia period, and are more likely to develop allergies than a single drug.

◆What substances in anesthesia can cause allergies?

Strictly speaking, almost all drugs may cause allergic reactions, and even white tape, film and other items have been reported to have allergies. It's just that some have a higher incidence and some have a lower incidence.

The main drugs or substances that cause perioperative allergic reactions are antibiotics, muscle relaxants, latex, gelatin, lipid local anesthetics, blood products, protamine, etc.; the incidence rate in women is 2~ that of men. 2.5 times.

Previous history of allergies, asthma, muscle relaxant cross-reactivity (patients allergic to one muscle relaxant may also be allergic to other muscle relaxants), and latex-fruit syndrome (a history of allergy to tropical fruits) patients with an increased risk of latex allergy) are a high risk factor for perioperative anaphylaxis.

◆Isn’t surgery too scary?

◎Don’t worry too much

The incidence of severe allergic reactions during the perianaesthesia period is very low, and most patients do not need special examinations. However, in view of the safety of patients with severe allergic reactions, Threats must be taken seriously for high-risk patients, such as:

If you do not have the above symptoms and medical history, but only occasionally have sporadic rashes and itching, do not be too nervous and do not need routine preoperative testing.

◆What can patients do?

◎Explain it to the anesthesiologist

Patients should record clear or highly suspected allergic drugs or foods in the past, and be as detailed as possible during the preoperative visit with the anesthesiologist. Describe the symptoms that occur during allergy, so that doctors can identify whether it is a severe allergic reaction and determine the intraoperative medication plan.

◆What to do if allergies occur?

Once typical symptoms appear, the suspected drug must be stopped immediately and the circulation stabilized:

Allergic reaction treatment process

1

Quick Crystalloid solution is infused to replace fluid lost due to capillary leakage and maintain effective circulating volume.

Five major causes of cardiovascular anaphylactic shock: increased thoracic pressure, pump failure, increased peripheral venous pressure, fluid entering the interstitium, and decreased peripheral resistance

2

When circulation is severely suppressed, phenylephrine, norepinephrine, and vasopressin can also be continuously infused intravenously.

Methylene blue can block nitric oxide-mediated dilation of vascular smooth muscle. When catecholamines and vasopressin are resistant, treatment with methylene blue is often effective. The loading dose of methylene blue is 1 mg/kg, 0.25 mg/kg intravenously every 4 hours.

Guidelines for the Management of Suspected Perioperative Allergy in Adults

3

Relieve Bronchospasm

4

Intravenous Injection Adrenocortical hormone:

Dexamethasone has a strong anti-inflammatory effect, but it has a slow onset and a long peak time (12~24 hours). It is not the first choice for allergic reactions. It is better to choose a hormone that does not require metabolism and acts directly on the receptor. Body hydrocortisone 1~2mg/kg, can be repeated after 6 hours. No more than 300mg in 24 hours.

Methylprednisolone 1mg/kg can also be injected intravenously.

5

Combination application of antihistamines: promethazine + ranitidine

Currently, there is no drug that can effectively prevent the occurrence of allergic reactions. When anaphylactic shock occurs, it is necessary to detect it promptly and deal with it decisively; 4 to 6 weeks after the patient recovers, a skin test should be completed to determine the allergen, and the patient and family should be informed, or an anaphylactic shock registration card should be issued, and the card should be held for the doctor's reference when seeing a doctor. .

Perioperative allergic reactions are clinical adverse events that most anesthesiologists will encounter. They are mostly sudden and incidental. The more urgent the onset, the more severe the symptoms. Anesthesiologists need to be able to quickly diagnose and correctly treat Treatment can stabilize the patient's vital signs, but even if timely treatment is given, the mortality rate of severe allergic reactions is still as high as 3%-6%.

Therefore, if there is no plan, no measures, and no medicines in clinical work, the best opportunity for discovery and treatment will be missed.

I recommend

Regarding perioperative allergic reactions, the BJA "British Anesthesia" magazine launched a column in July 2019 to introduce topics related to perioperative allergic reactions. Children's shoes who are interested You can check the following references:

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