[Challenge] How should you deal with sudden intraoperative awareness of patients during peri-anesthesia?

Intraoperative awareness notes for patients with sudden peri-anesthesia period One of the complications of anesthesia
.

Consciousness consists of subcortical mediated brain arousal and subjective experience mediated by the thalamocortical system, and memory consists of implicit memory (unconscious memory) and explicit memory (conscious memory)
.

Among them, intraoperative awareness with explicit memory is a common concern of patients and anesthesiologists, which may lead to serious psychological sequelae, such as post-traumatic stress disorder
.

The incidence of intraoperative awareness can be defined as the incidence of failure to suppress arousal, experience, and explicit memory during surgery with general anesthesia
.

The earliest intraoperative awareness was a medical report presented by Winterbottom in 1950, in which the patient had a clear recollection of pain, felt paralyzed, and heard conversations between physicians
.

Subsequent numerous prospective studies have confirmed the existence of intraoperative awareness
.

Studies in the United States and Europe have shown that the incidence of intraoperative awareness is on average 1 to 2 per 1000 patients, which is lower than that in Asian countries, which may be related to differences in anesthesia techniques
.

In Asian regions, such as China and Thailand, the incidence of intraoperative awareness is relatively high
.

The average incidence of intraoperative awareness in China is 3 to 4 cases per 1000 patients, and the incidence of intraoperative awareness in Thailand is 1.
05%
.

However, the sample size of the study in China is relatively small, and there is still a lack of large-sample multicenter studies on intraoperative awareness
.

Intraoperative awareness is an unpleasant experience and a serious complication during general anesthesia
.

Once intraoperative awareness occurs, it will affect the patient to varying degrees.
In mild cases, the patient only has auditory perception and recall, without pain or other perceptions; in severe cases, the patient will also have pain perception and numbness (such as feeling restrained).
feeling, unable to speak and breathe), anxiety, suffocation, near death,
etc.

In severe cases, post-traumatic stress disorder (PTSD) can be caused, manifested as psychological and behavioral abnormalities, insomnia, repeated nightmares, fear of surgery and even hospital, mental disorders, etc.
The symptoms can last for months or years
.

At present, the hospital's core system includes continuous improvement of medical quality.
From this purpose, it is imperative to study intraoperative awareness
.

Intraoperative awareness during general anesthesia was generally considered to be a rare complication, but with the in-depth study of intraoperative awareness (especially implicit memory) and the continuous development of psychological testing methods, monitoring during general anesthesia to intraoperative awareness The incidence of awareness has gradually increased
.

Intraoperative awareness can lead to severe psychological stress or mental disorders in patients, and even form malignant medical disputes; at the same time, intraoperative awareness also brings a rather difficult passive situation to the anesthesiologists involved
.

It can be seen that the safety of doctors and patients caused by awareness during general anesthesia is worthy of our deep consideration
.

2.
Analysis of the causes of intraoperative awareness in patients with sudden peri-anesthesia period It is reported that intraoperative awareness during general anesthesia is related to the following risk factors: female patients, intraoperative use of laryngeal mask for airway management, lack of a certain period of time during the maintenance of anesthesia Volatile anesthetics were used or not used in the whole process, the intraoperative blood pressure fluctuated significantly, and benzodiazepines and other anterograde amnestic drugs were not used before surgery, and inappropriate light anesthesia was used
.

Therefore, if general anesthesia patients have the above high-risk factors, we should be alert to the occurrence of intraoperative awareness
.

It is generally believed that intraoperative awareness during general anesthesia is an unavoidable anesthesia complication, and there are many factors that lead to intraoperative awareness, such as anesthesiologists' factors, patients' own factors, and anesthesia equipment factors
.

These factors lead to complicated reasons for intraoperative awareness, such as: the technical level of the physician performing the anesthesia; the use of muscle relaxants to shallow the depth of anesthesia for surgical requirements; , while ignoring the role of consciousness inhibition; in order to ensure the patient's hemodynamic stability, anesthesiologists consciously reduce anesthesia; individual differences in patients' response to drugs, such as female patients are more likely to be aware of intraoperative awareness than men; general anesthesia drugs are discontinued Premature; abnormal anesthesia equipment was not detected in time,
etc.

A variety of preventive measures have been carried out for intraoperative awareness during general anesthesia
.

In order to avoid intraoperative awareness, it is required to strengthen humanistic and technical care for patients before, during and after operation
.

Preoperative anesthesiologists should fully evaluate patients, detect patients who are prone to intraoperative awareness very early, communicate effectively with patients with high risk factors and their families, and even use drugs to reduce their psychological burden if necessary
.

During the operation, the medical staff should restrain their own behavior, not to talk about the patient's condition, complain about the process of the operation, and must prohibit all comments that disrespect the patient or cause the patient's mental trauma, and pay attention to the patient's privacy; at the same time, the anesthesiologist should strengthen the anesthesia of the patient during the operation.
Depth monitoring, rational use of analgesia, muscle relaxants and anesthetics, to maintain anesthesia at an appropriate depth
.

The patients should be followed up within one day after the operation, and the patients with confirmed or suspected intraoperative awareness must be dealt with as soon as possible
.

As anesthesia procedures and monitoring techniques have advanced greatly, the risk factors known during surgery may also have changed
.

Currently, these factors are generally patient- and procedure-related factors
.

Patient-related factors include: 1.
The patient develops genetic resistance or acquired resistance to anesthetics
.

② Patients who habitually drink alcohol may need more doses of anesthetics
.

③ Cardiovascular surgery patients have low cardiac functional reserve and cannot tolerate high-dose anesthetics, and are prone to intraoperative awareness under low-dose anesthesia
.

④ Patients with difficult endotracheal intubation are at high risk of intraoperative awareness, which may be due to insufficient depth of anesthesia during prolonged intubation attempts
.

⑤ Patients with mutations in the melanocortin receptor gene have higher requirements for inhalation anesthesia than patients without such mutations
.

Surgery-related factors include: ①The use of muscle relaxants can increase the incidence of intraoperative awareness
.

②Compared with inhalation anesthesia, total intravenous anesthesia has a higher proportion of intraoperative awareness, probably because in inhalation anesthesia, anesthesiologists can use modern technology to routinely monitor the anesthetic gas exhaled by patients and set low-concentration alarms, while intravenous anesthesia These conditions are not met
.

③ Human error, such as miscalculation of anesthetic dose,
etc.

3.
Coping strategies for intraoperative awareness in patients with sudden anesthesia during the perioperative period It is currently believed that the following measures are beneficial to reduce the occurrence of intraoperative awareness in the perioperative period: (1) When light anesthesia cannot be avoided during the operation (such as open heart surgery, trauma surgery, etc.
) or cesarean section, etc.
) can be discussed with these patients before surgery to inform them that they may be at risk of intraoperative awareness
.

② Drugs with amnestic effects, such as benzodiazepines and scopolamine, should be used before or during surgery, especially for patients who may be under light anesthesia during surgery
.

③ Rational use of muscle relaxants and analgesics, as well as other intravenous anesthetics, to avoid simple muscle relaxation
.

Unless surgically required, keep the monitoring of four clusters of stimulation to a minimum
.

Monitor the concentration of anesthetic drugs and give at least 0.
6 to 0.
8 MAC of inhalation anesthetics
.

④ Sufficient induction dose and body movement are important signs of shallow anesthesia or insufficient depth of anesthesia
.

For patients with difficult endotracheal intubation, attention should also be paid to additional sedative drugs in a timely manner
.

⑤ Apply sedation depth monitor
.

EEG bispectral index (BIS) can reduce the incidence of intraoperative awareness
.

⑥ Operating room staff should avoid inappropriate comments, jokes, discuss other patients or irrelevant topics, or use earplugs for patients.
Reducing sound stimulation may reduce the occurrence of intraoperative awareness
.

⑦ Regularly maintain and repair the anesthesia machine and its vaporizer, carefully check the anesthesia machine and ventilator before implementing anesthesia, and confirm the reliability of various devices and monitoring equipment
.

⑧ Anesthesiologists should be vigilant about the use of beta-receptor antagonists, calcium channel blockers, and those that can mask the physiological reactions caused by light anesthesia
.

Once a patient is found to have suffered intraoperative awareness, the current common practice is that the relevant medical staff take timely measures to communicate with the patient and their family members, and try to promote the patient to restore physical and mental health
.

1.
Effective communication between anesthesiologists and patients 2.
Early psychological intervention 3.
Improvement of patient sleep The exact boundaries of the patient's loss of consciousness
.

Preoperative, intraoperative and postoperative humanistic and technical care for patients can reduce intraoperative awareness, but it is still impossible to fundamentally prevent intraoperative awareness
.

Therefore, the complete avoidance of intraoperative awareness during general anesthesia is still a daunting task and challenge worldwide.
Only by truly understanding the mechanism of consciousness and the effects of different anesthetic drugs on the components of consciousness can the fundamental solution be
.

1.
Reassessment of drugs and monitoring methods for preventing intraoperative awareness Currently, it is agreed that the application of drugs with amnesic effects before or during surgery can effectively prevent intraoperative awareness
.

Midazolam is a benzodiazepine drug with good anterograde amnesia, sedative, hypnotic and anticonvulsant effects.
It has been routinely used in many hospitals to prevent intraoperative awareness during general anesthesia
.

There are two ways to monitor the depth of anesthesia in clinical practice today: one is conventional monitoring of the depth of anesthesia, such as monitoring the dose and concentration of anesthetic drugs and the patient's vital signs (blood pressure, heart rate, and the presence or absence of body movement, sweating, tearing, pupils, etc.
).
size, etc.
)
.

The emphasis on routine monitoring can reduce the rate of intraoperative awareness, but the sensitivity and relative specificity of routine monitoring are low, so that it has little effect on preventing intraoperative awareness
.

Another kind of monitoring is the monitoring of neurophysiological indicators, commonly used monitoring such as bispectral index (BIS) and auditory evoked potential (AEP).
It is not necessarily related to the occurrence of intraoperative awareness, and there are individual differences; studies have shown that patients with BIS>60 and maintained for more than 4 minutes did not have intraoperative awareness.
know
in.

Therefore, although BIS and AEP can more objectively reflect the degree of sedation and guide the rationalization of anesthesia medication, it is difficult to accurately reflect the degree of excitation and inhibition of the central nervous system of the brain and spinal cord only by the values ​​of B1S and AEP.
The index value cannot currently be recognized as the gold standard for monitoring the depth of anesthesia
.

How to choose a monitoring method to effectively monitor the depth of general anesthesia and completely eliminate intraoperative awareness requires further research
.

2.
Intraoperative awareness of general anesthesia and occupational protection of anesthesiologists: Anesthesiologists provide patients with general anesthesia and resolve their pain while leading to intraoperative awareness, which damages the interests of patients and burns themselves; how to ensure the legality of anesthesiologists in this incident Interests deserve attention
.

(1) Optimization and compliance of the general anesthesia plan (2) The formulation of the intraoperative awareness treatment process of general anesthesia: If intraoperative awareness unfortunately occurs during general anesthesia, it is beneficial to control the formulated treatment process and deal with the conflict between doctors and patients according to the established procedures.
Avoiding the panic of the anesthesiologist involved will help managers to distinguish right from wrong and protect the interests of both doctors and patients
.

(3) Reasonable adjustment by the management department: patients are unwilling to cause unnecessary damage to their physical and mental health during general anesthesia, and the medical staff involved have no choice but to do anything about the occurrence of intraoperative awareness
.

Faced with the statements of both doctors and patients, the relevant management departments or coordinators should respect the objective facts, mediate conflicts, resolve conflicts, promote consensus, strive to safeguard the reasonable interests of both parties, perform their obligations, and jointly accept, think about, and solve problems caused by intraoperative knowledge.
problem
.

(4) Enhancement of the ability of anesthesiologists to safeguard professional rights and interests: Anesthesiologists should be frank in their attitude towards accusations and related complaints of patients and their families due to their knowledge during surgery, and not deliberately avoid them; , and actively face the series of procedures for dealing with disputes caused by intraoperative knowledge
.

The anesthesiologists concerned should carefully analyze and summarize the reasons for the knowledge during the operation and the whole process of treatment.
In appropriate circumstances, they can share and encourage them with their colleagues through appropriate methods
.

5.
Sharing of typical cases known during surgery in patients with sudden anesthesia during the peri-anesthesia period The patient, female, 32 years old, weighing 48 kg, was diagnosed with micromammary tract disease, and planned to perform breast augmentation under general anesthesia
.

Preoperative evaluation showed good general condition with an ASA I grade
.

After entering the operating room, electrocardiogram, blood pressure and SpO2 were routinely monitored.
The basal heart rate was measured at 75 beats/min, blood pressure was 105/65 mmHg, and SpO2 was 100%
.

The peripheral vein was opened, and anesthesia was induced after oxygen inhalation and denitrogenation.
Midazolam 2 mg, fentanyl 0.
1 mg, propofol 100 mg, and rocuronium bromide 35 mg were intravenously injected, and a No.
4 laryngeal mask was successfully placed
.

After the laryngeal mask is inflated, connect the anesthesia machine, check bilateral breath sounds are symmetrical, thoracic rise and fall is normal, no air leakage, control breathing, adjust breathing parameters, maintain PCO2 at 4.
5~5.
0kPa (lkPa≈7.
5mmHg), and inhaled drugs are maintained at 2% sevoflurane
.

The operation started 35 minutes after anesthesia, and body movements occurred during skin incision, and fentanyl 0.
1 mg, propofol 50 mg, and vecuronium 2 mg were administered intravenously immediately
.

At 90 minutes of anesthesia, body motions reappeared, and propofol 50 mg and fentanyl 0.
05 mg were administered intravenously immediately
.

20 minutes after the dosing, propofol 50 mg was given again due to body movement, and the sevoflurane vaporizer was found to be lacking
.

After the addition, the inhaled sevoflurane concentration was 2%, and there was no physical movement until the end of the surgery
.

It lasted 135 minutes from the beginning of anesthesia to the end of the operation.
During the whole operation, the patient's heart rate was maintained at 55 to 70 beats/min, and the mean arterial pressure was maintained at 65 to 70 mmHg.
There was no abnormality on the intraoperative monitor
.

At the end of the operation, sevoflurane was turned off, and breathing resumed 5 minutes after stopping machine-controlled breathing
.

Send the patient to the recovery room to continue observation for 10 minutes and then pull out the laryngeal mask
.

5 minutes later, when the patient was awake, the patient was abnormally excited, cried, and told the contents of intraoperative awareness and doctor's conversation
.

At this time, the anesthesiologist confirmed that the patient had intraoperative awareness, and immediately gave psychological counseling, and immediately administered midazolam 2 mg and propofol 50 mg intravenously, followed by micro-pump infusion at the rate of propofol 50 mg/h
.

At the same time, the anesthesia staff gave psychological counseling and explanations beside the patient's ear.
At this time, the patient was in a light sleep state and could nod his head as instructed
.

After 90 minutes, the propofol infusion was stopped, and the patient was awake and returned to the ward with a stable mood
.

There was no special follow-up for 2 consecutive days after operation
.