Wondershare EdrawMind
MindMap Gallery anaesthetization
- 8
anaesthetization
It is generally believed that anesthesia is a reversible functional suppression of the central nervous system and/or peripheral nervous system produced by drugs or other methods. This suppression is mainly characterized by the loss of sensation, especially pain. The word anesthesia comes from the Greek word narkosis. As the name suggests, anesthesia means numbness and paralysis, and drunkenness means drunken coma.
Edited at 2022-11-07 14:28:17
- cáncer de pulmón
El cáncer de pulmón es un tumor maligno que se origina en la mucosa bronquial o las glándulas de los pulmones. Es uno de los tumores malignos con mayor morbilidad y mortalidad y mayor amenaza para la salud y la vida humana.
- diabetes
La diabetes es una enfermedad crónica con hiperglucemia como signo principal. Es causada principalmente por una disminución en la secreción de insulina causada por una disfunción de las células de los islotes pancreáticos, o porque el cuerpo es insensible a la acción de la insulina (es decir, resistencia a la insulina), o ambas cosas. la glucosa en la sangre es ineficaz para ser utilizada y almacenada.
- sistema digestivo
El sistema digestivo es uno de los nueve sistemas principales del cuerpo humano y es el principal responsable de la ingesta, digestión, absorción y excreción de los alimentos. Consta de dos partes principales: el tracto digestivo y las glándulas digestivas.
anaesthetization
- cáncer de pulmón
El cáncer de pulmón es un tumor maligno que se origina en la mucosa bronquial o las glándulas de los pulmones. Es uno de los tumores malignos con mayor morbilidad y mortalidad y mayor amenaza para la salud y la vida humana.
- diabetes
La diabetes es una enfermedad crónica con hiperglucemia como signo principal. Es causada principalmente por una disminución en la secreción de insulina causada por una disfunción de las células de los islotes pancreáticos, o porque el cuerpo es insensible a la acción de la insulina (es decir, resistencia a la insulina), o ambas cosas. la glucosa en la sangre es ineficaz para ser utilizada y almacenada.
- sistema digestivo
El sistema digestivo es uno de los nueve sistemas principales del cuerpo humano y es el principal responsable de la ingesta, digestión, absorción y excreción de los alimentos. Consta de dos partes principales: el tracto digestivo y las glándulas digestivas.
- Recommended to you
- Outline
Preparation before anesthesia and medication before anesthesia (2) Physical and mental preparation of the patient
- 4
anaesthetization
Preparation before anesthesia and medication before anesthesia
Pre-anesthesia assessment
Medical history collection
Atropine is contraindicated in glaucoma
Use pethidine with caution in patients taking monoamine oxidase inhibitors
Physical examination
laboratory tests
Physical Status Assessment Grading
Ⅰ
Healthy body, good development and nutrition, and normal functions of various organs
Mortality rate: 0.06~0.08%
Ⅱ
In addition to surgical diseases, there are mild comorbidities and functional compensation is sound.
Mortality rate: 0.27~0.40%
Ⅲ
Comorbidities are severe and physical activities are limited, but they are still able to cope with daily activities
Mortality rate: 7.82～4.30%
Ⅳ
Severe co-morbidities, loss of ability to perform daily activities, and often life-threatening
Mortality rate: 7.80~23.0%
Ⅴ
Dying patients who cannot sustain life for 24 hours regardless of surgery or not
Mortality rate: 9.40~50.7%
Ⅵ
Diagnosed as brain dead, his organs are planned to be used for organ transplant surgery
mortality rate:--
Preanesthetic evaluation of comorbid conditions
Preparation before anesthesia
Cardiovascular System
Preparation before anesthesia
Control blood pressure <180/100mmHg, angina pectoris, arrhythmia, and hypertension until the same day.
Perioperative Preoperative Preparation
Hypertensive patients with blood pressure <160/100mmHg do not need special preparation. Those with blood pressure >180/100mmHg should take appropriate antihypertensive drugs before surgery.
respiratory system
Preparation before anesthesia
Stop smoking for ≥2 weeks before surgery, perform respiratory function exercises, aerosol inhalation, and physical therapy to promote sputum excretion
Perioperative Preoperative Preparation
Stop smoking for 2 weeks before surgery, postpone elective surgeries for acute infections, use bronchodilators for COPD, and postpone elective surgeries for asthma attacks.
diabetes
Preparation before anesthesia
For elective surgery, blood sugar is controlled to ≤8.3mmol/L, urine glucose is lower than ( ), and urine ketone bodies are negative. Patients with DKA should use intravenous insulin to eliminate ketone bodies and correct acidity.
Perioperative Preoperative Preparation
For elective surgery, blood sugar should be controlled to 5.6-11.2mmol/L. Oral hypoglycemic drugs should be stopped late 1 day before surgery (chlorpropamide 2-3 days before surgery). Patients with diabetic ketoacidosis should use insulin to expand volume and correct acid.
Gastrointestinal tract preparation
Preparation before anesthesia
Empty the stomach to prevent reflux and aspiration of gastric contents
Adults should fast from digestible solid foods for at least 6 hours before surgery and fat and meat foods for at least 8 hours.
Newborns and infants should not tolerate breast milk for at least 4 hours, easily digestible food, and infant formula for at least 6 hours.
Perioperative Preoperative Preparation
Empty the stomach (fast for 8 to 12 hours before surgery and drink for 4 hours). Eat liquid food 1 to 2 days before gastrointestinal surgery. Cleanse enema 1 day before colorectal food and early morning on the day of surgery. Start taking it 2 to 3 days before surgery. Liquid food, oral intestinal bacteriostatic drugs
Pre-anesthetic medication
Purpose
Eliminate the patient's nervousness, anxiety and fear; enhance the effect of general anesthetics and reduce the side effects of general anesthetics: produce amnesia for adverse stimuli
Raise the patient's pain threshold, relieve or contact the pain caused by the original disease or invasive procedures before anesthesia
Eliminate adverse reactions caused by surgery or anesthesia, especially vagal reflexes, and inhibit sympathetic nerve excitation to maintain hemodynamic stability
drug selection
Patients under general anesthesia are mainly treated with sedatives, and those with severe pain are treated with home narcotic analgesics. Patients with spinal anesthesia are mainly treated with sedatives. Epidural anesthesia may provide analgesics as appropriate
Commonly used drugs
Tranquilizer
Mediterranean, midazolam
Stable, sedative, hypnotic, anti-anxiety, anti-convulsant
hypnotics
Phenobarbital
Sedative, hypnotic, anticonvulsant
analgesics
Morphine, pethidine
analgesia, sedation
anticholinergics
Atropine, scopolamine
Inhibit gland secretion, relieve smooth muscle spasm and vagus nerve excitement
general anesthesia
general anesthetic
inhalation anesthetic
Physicochemical properties and pharmacological properties
The intensity of inhalation anesthetics is based on the minimum alveolar concentration (MAC)
It refers to the lowest alveolar concentration that can prevent 50% of patients from shaking their heads or moving their limbs during skin incision when inhaled with pure oxygen at one atmospheric pressure.
Factors Affecting Alveolar Drug Concentrations
ventilation efficiency
Increased ventilation has a significant impact on the increase in FA/FI (FA/FI: alveolar concentration/inhaled drug concentration)
concentration effect
The concentration of inhaled drugs not only affects the level of FA, but also affects the rate at which FA rises. That is, the higher the FI, the faster the FA rises. This phenomenon is called the concentration effect.
cardiac output
Anesthetics are transferred from the alveoli to the blood by diffusion
blood/gas distribution coefficient
Refers to the amount of dissolved gas in unit volume of blood when anesthetic gas and blood reach equilibrium.
The concentration difference of anesthetics in alveolar and venous blood (Fa-v)
The concentration difference of anesthetics in alveoli and venous blood (Fa-v): The greater the Fa-v, the greater the amount of drug taken up by the pulmonary circulation, that is, the more anesthetics are taken away from the alveoli by the pulmonary blood.
Metabolism and toxicity
Most anesthetics are excreted from the respiratory tract, and only a small part is excreted in the urine after being metabolized in the body.
The main metabolic site is the liver
Cytochrome P₄₅₀ is an important drug oxidative metabolism enzyme that can accelerate the oxidative metabolism process of drugs.
Commonly used inhalation anesthetics
nitrous oxide
MAC: 105%
Pharmacological characteristics: It has a mild inhibitory effect on myocardium and respiration, has weak anesthetic properties, and should not be used in intestinal obstruction.
Clinical application: compounded with other general anesthetics for anesthesia maintenance
Special indications: rarely used clinically. It can increase intraintestinal pressure and should not be used in cases of intestinal obstruction.
Laugh at the bumpy road of life (intestinal obstruction)
Sevoflurane
MAC：2%
Pharmacological characteristics: It can dilate cerebral blood vessels, cause intracranial pressure to increase, mildly inhibit myocardium, and strongly inhibit breathing.
Clinical applications: induction and maintenance of anesthesia
Special indications: Quick awakening after anesthesia, low incidence of nausea and vomiting
Desflurane
MAC: 6%
Pharmacological characteristics: mildly inhibits myocardium and respiration, inhibits neuro-myocardial junction effect, and strongly inhibits respiration.
Clinical application: maintenance of anesthesia
Special indications: cardiac surgery (little impact on circulation) (kind-hearted)
intravenous anesthetic
Ketamine
Dissociative anesthesia: separation of movement and sensation
Pharmacological characteristics: It can increase blood pressure and intraocular pressure, and is contraindicated in patients with hypertension and glaucoma.
Clinical application: induction of general anesthesia, basic paralysis in infants
etomidate
Pharmacological characteristics: short-acting hypnotic, no analgesic effect, little interference on the cardiovascular system, suitable for patients with cardiovascular system diseases
Clinical manifestations: induction of general anesthesia, anesthesia for the elderly, frail and critically ill patients
isophenol
Pharmacological characteristics: Sedative and hypnotic, mild analgesia, great inhibitory effect on cardiovascular system
Clinical application: intravenous induction of general anesthesia
midazolam
Pharmacological characteristics: short-acting anesthesia and sedation, mild impact on the cardiovascular system, inhibiting breathing, and reducing intracranial pressure.
Clinical applications: preoperative anesthesia, induction and maintenance of anesthesia
Dexmedetomidine
Pharmacological characteristics: Can produce dose-dependent sedative, anxiolytic and analgesic effects. Sudden discontinuation of medication can produce withdrawal symptoms
Clinical application: intraoperative sedation, auxiliary medication for general anesthesia, sedation for mechanically ventilated patients
muscle relaxants
Mechanism of action and classification
Depolarizing muscle relaxants
Represented by succinylcholine. The molecular structure of succinylcholine is similar to acetylcholine, and it can bind to acetylcholine receptors to cause postsynaptic membrane depolarization and muscle fiber bundle contraction.
Features
Put the postsynaptic membrane into a state of continuous depolarization
After the first injection, before the muscle relaxation effect occurs, there may be muscle fiber bundle tremor, which is the result of uncoordinated muscle fiber contraction.
Cholinesterase inhibitors not only fail to antagonize its muscle relaxant effect, but actually enhance it.
non-depolarizing muscle relaxants
Represented by tubocurarine. This type of muscle relaxant can bind to acetylcholine receptors in the postsynaptic membrane but does not cause depolarization of the postsynaptic membrane.
Features
The blockade site is at the neuromuscular junction, occupying acetylcholine receptors on the postsynaptic membrane.
When nerves are excited, the amount of acetylcholine released from the presynaptic membrane does not decrease, but it cannot function.
There is no muscle fiber bundle contraction before muscle relaxation occurs.
Antagonized by cholinesterase inhibitors
Commonly used muscle relaxants
Depolarizing muscle relaxants
Representative drug succinylcholine
Pharmacological mechanism: It can bind to acetylcholine receptors in the postsynaptic membrane, causing depolarization of the postsynaptic membrane and causing muscle fiber bundle contraction.
Cholinesterase: Succinylcholine is not decomposed by cholinesterase, so it has a long action time, so that the postsynaptic membrane cannot repolarize and is in a continuous depolarization state, and it no longer has any effect on acetylcholine released by nerve impulses. , resulting in muscle relaxation
Cholinesterase inhibitors: Cholinesterase inhibitors not only fail to antagonize its muscle relaxant effect, but actually enhance it.
Succinylcholine (Succinylcholine)
non-depolarizing muscle relaxants
Representative drug: tubocurarine
Pharmacological mechanism: It can bind to acetylcholine receptors in the postsynaptic membrane, but does not cause depolarization of the postsynaptic membrane, so there is no muscle fiber bundle contraction.
Cholinesterase: tubocurarine binds to acetylcholine receptors in the postsynaptic membrane. When more than 75% to 80% of the acetylcholine receptors in the postsynaptic membrane are occupied by tubocurarine, nerve impulses can cause nerve endings to Releases acetylcholine, but cannot conduct nerve impulses, so it cannot cause muscle contraction
Cholinesterase inhibitors: The muscle relaxant effect can be antagonized by cholinesterase inhibitors
Vecuronium (Vancoronin), Rocuronium (Ecoson), Cisatracurium
Precautions when using muscle relaxants
Establish an artificial airway and implement assisted or controlled breathing.
Muscle relaxants have no analgesic or sedative effects and cannot be used alone. They should be used in combination with other general anesthetics.
Hypothermia prolongs the action of muscle relaxants
In patients with neuromuscular junction, the use of non-depolarizing muscle relaxants is contraindicated
Myasthenia gravis does not require non-depolarizing muscle relaxants
Some muscle relaxants have a histamine-releasing effect and should be used with caution by those with a history of asthma and allergies.
Narcotic analgesics
Mechanism of action and classification
Commonly used drugs include opioids, which bind to opioid receptors in the body.
Commonly used medicines
morphine
Opioids derived from opium
It has good sedative and analgesic effects. It is often used as a pre-anesthetic drug and an anesthetic auxiliary drug, and can be combined with hypnotics and muscle relaxants to perform general anesthesia.
Pethidine
Has analgesic, hypnotic and smooth muscle spasm relief effects
It has an inhibitory effect on myocardial contractility. It has a mild inhibitory effect on breathing and is useful in pre-anesthetic medication or acute pain treatment.
Fentanyl
Effects on the central nervous system are similar to other opioids
It has an inhibitory effect on myocardial contractility.
It can be used as an auxiliary drug for intraoperative/postoperative analgesia, regional anesthesia, and is also commonly used for anesthesia in cardiovascular surgery.
remifentanil
ultra short acting analgesics
It can be used to induce anesthesia and maintain analgesia during surgery, and to inhibit the reaction during tracheal intubation.
Shufentanil
Fentanyl derivatives
Less interference with the circulatory system and more suitable for anesthesia for cardiovascular surgery
Administration of general anesthesia
induce
It refers to the period when the patient goes from being awake to losing consciousness and enters general anesthesia before undergoing tracheal intubation, which becomes the induction period of general anesthesia.
Mask inhalation induction method
Place the anesthesia mask on the patient's mouth and nose, turn on the anesthetic evaporator and allow the patient to inhale the anesthetic. When the patient loses consciousness and enters anesthesia, intravenously inject muscle relaxants for endotracheal intubation.
intravenous induction
First, inhale pure oxygen through a mask for 2 to 3 minutes. Select the intravenous anesthetic and dosage according to the condition. After injecting from the vein, use the anesthesia mask for artificial respiration, and then perform endotracheal intubation.
Compared with the inhalation induction method, intravenous induction is faster, the patient is more comfortable, and there is no environmental pollution, but it has greater interference with circulation.
Maintenance of general anesthetics
Inhalation anesthetics to maintain menstruation
A certain concentration of inhaled anesthetic is inhaled through the respiratory tract to maintain an appropriate depth of anesthesia.
nitrous oxide
The anesthetic properties are weak, and there is a risk of hypoxia at high concentrations. It is difficult to be used alone to maintain anesthesia.
Isoflurane, sevoflurane (volatile anesthetics)
It has strong anesthetic properties. Inhalation of high concentration can make the patient conscious and pain disappear, and it can be used alone for anesthesia.
Judgment of depth of general anesthesia
The standard for scoring the depth of ether anesthesia is based on the degree of suppression of consciousness, pain, reflex activity, muscle relaxation, breathing and circulation.
Management of respiratory tract
Maintaining airway patency is a prerequisite for respiratory management
Tongue drop is the most common cause of respiratory obstruction in non-general anesthesia patients during induction, recovery, and sedation.
Tilt the patient's head back or lift the mandible can often relieve respiratory obstruction caused by the tongue falling back. If necessary, an oropharyngeal or nasopharyngeal ventilator can be placed to prop up the fallen tongue base and pharyngeal soft tissue to contact the obstruction.
For patients under general anesthesia or those with insufficient mask ventilation, endotracheal intubation is the most commonly used artificial airway management technique.
During endotracheal intubation, the depth of the tube inserted into the trachea of the organ is 4 to 5 cm, and the distance between the tip of the tube and the central incisor is 18 to 22 cm.
General anesthesia depth grading
Stage I: Not suitable for surgery
Stage II: Any surgery is contraindicated
Stage III
Level 1: General surgery
Level 2: Abdominal Surgery
Level 3: More irritating surgery
Stage IV: Failure to rescue in time can lead to cardiac arrest
Complications of general anesthesia and their prevention and treatment
Reflux and aspiration
Common causes
After general anesthesia, the patient loses consciousness and the reflux causes aspiration.
Prevention and treatment: Reduce gastric retention, promote gastric emptying, and reduce intragastric pressure
upper respiratory tract obstruction
Common causes
Mechanical obstruction of the upper respiratory tract
Prevention and control
Before anesthesia, carefully select the endotracheal tube, regularly auscultate the lungs, and promptly remove respiratory secretions.
lower respiratory tract obstruction
Common causes
Tracheal tube kinking, bronchospasm
Prevention and control
Before anesthesia, carefully select the endotracheal tube, regularly auscultate the lungs, and promptly remove respiratory secretions.
hypoxemia
Common causes
Too deep anesthesia and excessive intraoperative blood loss can cause hypovolemic shock, allergic reactions, adrenal insufficiency, etc.
Prevention and control
Reduce anesthesia, replenish blood volume, restore vascular tone, and treat the cause
hypotension
During anesthesia, if the systolic blood pressure drops by more than 30% of the basic value or the absolute value is lower than 80mmHg, it should be dealt with promptly.
Common causes
Too deep anesthesia causes blood pressure to drop and pulse pressure to decrease. Excessive intraoperative blood loss can cause hypovolemic shock. Allergic reactions, hypoadrenocortical function
Prevention and control
Replenish blood volume, restore vascular tone and treat causes
hypertension
During anesthesia, systolic blood pressure higher than 160mmHg or rising by more than 30% of the basic value will increase blood loss.
Common causes
associated with comorbidities. Relevant to intraoperative and anesthesia operations. Hypoventilation causes CO2 retention. Drug-induced increase in blood pressure
Prevention and control
Remove inducements and ensure appropriate depth of anesthesia. Antihypertensive drugs can be administered appropriately to maintain circulatory stability.
Arrhythmia
Common causes
Improper depth of anesthesia, excessive surgical stimulation, hypotension, hypertension, CO2 retention and hypoxemia can induce arrhythmias.
Prevention and control
Remove inducements and maintain normal circulation volume, stable hemodynamics and balanced myocardial oxygen supply.
High fever, convulsions and convulsions
Common causes
Pediatric anesthesia
Prevention and control
Dantrolene
Notice
Accumulation of CO₂ occurs during anesthesia. High CO₂ can still stimulate breathing, so rapid ventilation is not allowed to cause CO₂ to be discharged too quickly.
Otherwise it will lead to apnea and a drop in blood pressure
With long-term CO₂ accumulation and hypoxemia, CO₂ no longer has the ability to stimulate breathing, and it relies entirely on hypoxia to stimulate breathing. Therefore, high-concentration oxygen cannot be given
Summarize
High CO₂, low O₂, slow and low flow oxygen supply
narcotic memory
Singing Qilixiang in the center of the earth in Yan'an, bah bah bah oh, laughing so hard that my heart breaks.
Enflurane - eye surgery
Desflurane - cardiac surgery
Sevoflurane-no vomiting (scent)
Isoflurane-hypertensive
Laughing gas-intestinal obstruction
Keep money, don’t bet on ketones, stay true to your heart
Thiopental-spasm
Ketamine - not used for high blood pressure
Etomidate-cardiovascular disease
Propofol - cardiovascular inhibitor
Local anesthesia
Pharmacology of local anesthetics
Classification of local anesthetics
Ester local anesthetics
Representative drugs: procaine (the least toxic), cardine
Metabolic pathway: hydrolyzed by plasma pseudocholinesterase
Allergic reactions: common
Toxic reactions: Visible
Limited amount at one time
Procaine 1000mg
Cardine 40mg (topical anesthesia), 80mg (nerve block)
Amide local anesthetics
Representative drugs: lidocaine, bupivacaine, ropivacaine
Metabolic pathway: hydrolyzed by mitochondrial enzymes in the liver, so the dose should be reduced when liver function is impaired
Allergic reactions: rare
Toxic reactions: Visible
Limited amount at one time
Bupivacaine: 150mg
Ropivacaine: 150mg
Lidocaine: 100mg (topical anesthesia) 400mg (nerve block/local infiltration)
memory
Same inside and outside
historical experience
memory
County radish
Adverse reactions
toxic reactions
Common causes
A single dose exceeds the patient's tolerance
accidental intravascular injection
The injection site has rich blood supply and faster absorption.
The patient's tolerance is reduced due to physical weakness and other reasons
clinical manifestations
In mild toxic reactions, patients often experience symptoms such as dizziness, multivocalism, drowsiness, chills, panic, and disorientation. If they continue to develop, they may lose consciousness and experience tremors of facial muscles and limbs. Once convulsions occur, they may suffer from respiratory distress. Difficult hypoxia leading to respiratory and circulatory failure
Early manifestations are mainly excitement, such as increased blood pressure and increased heart rate.
When the drug concentration continues to increase, the drug will appear to be completely inhibited.
prevention and treatment
Pre-anesthetic medications such as diazepam or barbiturates may be given.
The dosage of local anesthesia at one time should not exceed the limit. The dosage should be reduced according to the specific situation and the site of administration. An appropriate amount of epinephrine should be added to the liquid. No blood should be sucked back before injecting, and no blood should be aspirated. Pay attention to slow administration, etc.
Once a toxic reaction occurs, the medication should be stopped immediately and oxygen should be inhaled.
allergic reaction
Allergies to ester local anesthetics are common, but amide local anesthetics are extremely rare.
Once an allergic reaction occurs, first stop taking the medication, keep the respiratory tract open, inhale oxygen, maintain stable circulation, and replenish blood volume appropriately. In emergencies, vasopressors can be used appropriately, as well as glucocorticoids and antihistamines.
Notice
Anaphylactic shock is rare
Commonly used local anesthetics
Procaine
It is a weak, short-acting, but safer commonly used local anesthetic with weak anesthetic efficacy and poor mucosal penetration.
Because of its low toxicity, it is often used for local infiltration anesthesia, not for topical anesthesia and epidural anesthesia.
Cardine
Strong, long-lasting local anesthetic with poor mucosal penetration
Topical anesthesia, nerve block, spinal anesthesia, epidural block, generally not used for local infiltration anesthesia
lidocaine
A local anesthetic with medium anesthetic potency and duration, with good tissue dispersion and mucosal penetration.
Various local anesthesia, most suitable for nerve blocks, epidural anesthesia
Bupivacaine
A potent, long-lasting local anesthetic, highly bound to plasma proteins and rarely crosses the placenta.
Nerve block, spinal anesthesia, epidural block, more suitable for labor analgesia, rarely used for local infiltration anesthesia
Ropivacaine
A powerful, long-lasting local anesthetic with low cardiotoxicity and high plasma protein binding rate, suitable for labor analgesia.
Epidural block, especially suitable for epidural analgesia and labor analgesia
labor analgesia
Bupivacaine, Ropivacaine
Ibuprofen
local anesthetic mechanism
Onset of effect
dissociation constant
anesthetic potency
fat soluble
Action time
Protein binding rate
Local anesthesia method
topical anesthesia
A local anesthetic with strong penetrating power is applied to the surface of the mucosa, allowing it to penetrate the mucosa and block the nerve endings located under the mucosa, causing the mucosa to anesthetize.
Inner diameter inspection
local infiltration anesthesia
Inject local anesthetic into the tissue in the surgical area to block nerve endings and achieve anesthesia.
Four punctures
area block
Anesthesia is injected around and at the base of the surgical site to block the nerve fibers leading to the surgical site.
lumpectomy
nerve block
Inject local anesthetic around the nerve trunk, plexus, and node to block its impulse conduction and produce anesthesia in the area it controls.
brachial plexus block
Location: C₅～C₈ and anterior branch of T₁
Indications and routes: Interscalene approach (shoulder) Supraclavicular approach (upper extremity surgery). Axillary approach (forearm, hand)
complication
Interscalene pathway: phrenic nerve palsy, recurrent laryngeal nerve palsy, Horner syndrome, total spinal anesthesia
Supraclavicular route: pneumothorax (most common), phrenic nerve palsy, recurrent laryngeal nerve palsy, Horner syndrome
There may be pneumothorax in the supraclavicular path, and all other paths except pneumothorax are present.
cervical plexus block
C₁～C₄
Indications and routes: Thyroid surgery, tracheotomy
complication
Complications of superficial plexus block are rare and
Complications of deep plexus block: local anesthetic toxicity, phrenic nerve palsy, recurrent laryngeal nerve palsy, Horner syndrome. Accidentally enter the subarachnoid space or epidural space
intercostal nerve block
T₁～T₁₂anterior branch
Indications and route: performed at the rib angle or posterior axillary line
Complications: pneumothorax, local anesthetic toxicity
digital nerve block
finger/toe nerve
Indications: finger/toe surgery
Do not add epinephrine to the local anesthetic to avoid constriction of the supplying blood vessels, and do not inject too much to avoid compressing the blood vessels and causing finger gangrene.
Adrenaline added to local anesthetic
Purpose: Delay the absorption of local anesthetics and avoid or reduce poisoning
Dosage: The concentration of epinephrine added to local anesthetic is 1: (200,000 to 400,000) = 0.0005g = 0.5mg
Notice
T₂
upper edge of sternal manubrium
T₄
nipple connection
T₆
sword thrust down
T₈
rib costal
Season 8
T₁₀
Flat navel
T₁₂
2~3cm above pubic symphysis
neuraxial anesthesia
Applied anatomy of the spinal canal
spine and spinal canal
The spinal canal extends upward to the foramen magnum and downward to the sacral foraminal fissure. When lying on your back, C₃ and L₃ are the highest and T₅ and S₄ are the lowest.
ligament
from outside to inside
Skin - subcutaneous - supraspinal ligament - interspinous ligament - ligamentum flavum - epidural space - dura mater, arachnoid mater - subarachnoid space - pia mater - spinal cord
Spinal cord, meninges and lacunae
The lower end of the adult spinal cord is flat on the lower edge of L₁ or the upper edge of L₂, and the lower end of the spinal cord is flat on the lower edge of L₃ in newborns.
The spinal cord is felt from the inside to the outside as the pia mater, arachnoid mater and dura mater.
sacral canal
There is a rich venous plexus, and the average distance from the dural sac to the sacral hole is 47mm. If the needle is inserted too deep during sacral canal puncture, it may accidentally enter the subarachnoid space and cause total spinal anesthesia.
cerebrospinal fluid
The subarachnoid space is filled with cerebrospinal fluid, with a total volume of 120 to 150 ml and a specific gravity of 1.003 to 1.009.
Spinal nerves and blockade
The sequence of blockade is: sympathetic nerves - cold sense - temperature sense (disappeared) - temperature recognition sense - dull pain sense - sharp pain sense - touch - motor nerves (muscle relaxation) - pressure sense (weakened) - proprioception
Sympathetic nerve
Blocking effect: can reduce visceral stretch reaction
Blocking time: first block
Characteristics: The block level is 2 to 4 segments higher than the sensory nerve
sensory nerves
Blocking effect: can reduce pain transmission in skin and muscles
Dead time: Center
motor nerve
Blocking effect: can produce muscle relaxants
Block time: latest block
Characteristics: The block level is 1 to 4 segments lower than the sensory nerve
memory
When I first had a (sympathetic) girlfriend, I was very cold (cold feeling) towards her, and then she started to warm up (warm feeling). Suddenly one day I was broken up and hurt (dull pain→sharp pain), so I went to get in touch with her. Movement (kinesthesia), release of stress (pressure sensation). Finally regained self (proprioception)
Notice
The last to subside is the sympathetic nerve
subarachnoid space block
Classification
Dosing method
Single method and continuous method
anesthesia plane
If the block level reaches or is lower than T₁₀, it is low level. If it is higher than T₁₀ but lower than T₄, it is mid level. If it reaches T₄ or above, it is high level spinal anesthesia.
Proportion of local anesthetic solution
According to the specific gravity of the medicinal solution used, it is higher, lower, or equal to the specific gravity of cerebrospinal fluid. They are called heavy specific gravity, equal specific gravity, and light specific gravity. Spinal anesthesia
spinal anesthesia
Generally, the lateral decubitus position is used, and the seat is often used for sellar area anesthesia. The puncture point for adults is generally the L₃~L₄ space (no spinal cord)
When the needle passes through the ligamentum flavum, there is often an obvious feeling of loss. When the needle is inserted again to puncture the dura mater, a second feeling of loss occurs. When you pull out the needle core and see cerebrospinal fluid dripping out of the needle, it means the puncture was successful.
Commonly used drugs for spinal anesthesia
Procaine
The dosage for adults is 100 to 150 mg at a time, and 50-q00 mg for sellar area anesthesia.
Cardine
The dosage for adults is 8mg to 15mg.
Bupivacaine
The usual dosage is 8 to 15 mg
Adjustment of anesthesia level
Postural adjustment plays a very important role, including adjusting height, adjusting side position
Puncture gap: The higher the puncture gap, the higher the anesthesia level and the wider the range.
Injection speed: the faster the speed, the wider the range, generally 1ml/5s
Anesthetic Dosage: Key Factors
Notice
Regardless of the type of anesthetic
complication
intraoperative complications
Blood pressure drops, heart rate slows (common)
The incidence and severity of blood pressure drop during spinal anesthesia are closely related to the level of anesthesia
When blood pressure drops significantly, 200 to 300 ml of intravenous fluid can be quickly infused to expand blood volume. If necessary, ephedrine can be injected intravenously.
If the heart rate is too slow, atropine can be injected intravenously
Notice
Shock is a contraindication to spinal anesthesia
Respiratory depression
It often occurs in patients with high-level spinal anesthesia. Due to extensive thoracic spinal nerve block and intercostal muscle paralysis, the patient feels chest tightness, shortness of breath, difficulty speaking, weakened thoracic breathing, and cyanosis.
In case of respiratory insufficiency, oxygen should be given and a mask should be used to assist breathing. Once breathing stops, endotracheal intubation and artificial respiration should be performed immediately
feel sick and vomit
If the level of anesthesia is too high, hypotension and respiratory depression may occur, causing cerebral ischemia and hypoxia, which may excite the vomiting center.
Hyperactive vagus nerve, enhanced gastrointestinal motility
Retraction of abdominal viscera
Adverse reactions caused by other medications used during surgery
Postoperative complications
pain after spinal anesthesia
The incidence rate is 3 to 30%, often appearing 2 to 7 days after anesthesia, and is more common in young women.
Characteristics: The headache worsens when raising the head or sitting up, and decreases or disappears after lying down. The occurrence of headache has nothing to do with the type of anesthetic, but is related to the thickness of the puncture needle or repeated punctures.
reason
low pressure headache
The dura mater and arachnoid mater have poor blood supply, the puncture hole is not easy to heal, and intracranial pressure decreases due to cerebrospinal fluid leakage.
vascular headache
Vascular headache caused by dilation of intracranial blood vessels
prevention
Use a conical non-cutting fine puncture needle (26G); the bevel of the puncture needle should be horizontal to the long axis of the spinal cord to avoid repeated punctures. Sufficient fluid should be injected during the perioperative period to prevent dehydration.
treat
Rest on your back, take oral analgesics and tranquillizers
Acupuncture or using a belly band to tighten the abdomen
In severe cases, normal saline, 5% glucose, and 15-30ml of dextran can be injected into the epidural space.
It is strictly forbidden to use hypertonic glucose or mannitol: it will cause dehydration and worsen the condition.
epidural autologous filling method
urinary retention
More common. Because the parasympathetic nerve fibers that control the bladder are very thin and sensitive to local anesthetics, recovery after blockade is delayed.
Hot compresses, acupuncture, or intramuscular injection of the parasympathetic stimulant carbachol can be used
Neurological complications after spinal anesthesia
cranial nerve palsy
adhesive arachnoiditis
cauda equina syndrome
purulent meningitis
Can be caused by direct or indirect reasons
epidural space block
Commonly used
lidocaine, tetracaine, bupivacaine, ropivacaine
Injection method
Since the injection amount of epidural anesthesia is 3 to 5 times larger than that of spinal anesthesia, the amount and method of injection should be strictly controlled. Under normal circumstances, first give a test amount, that is, 3 to 5 ml of 2% lidocaine, and observe for 5 to 10 minutes. If there is no spinal anesthesia, additional dosage can be given
Adjustment of anesthesia level
local anesthetic volume
The larger the injection volume, the wider the diffusion and the wider the anesthesia range.
Puncture gap
The height of the upper and lower planes of anesthesia depends on the height of the puncture gap.
Catheter direction
If the catheter is placed toward the head, the drug solution will easily spread to the chest and neck; if the catheter is placed toward the tail, the solution will easily spread to the waist and sacral segments.
Injection method
The same amount of medicine is used. If it is injected concentratedly at one time, the area of anesthesia will be wide, but if injected in divided doses, the area will be narrowed.
Patient condition
Elderly patients, arteriosclerosis, pregnancy, dehydration, cachexia, etc., the range of anesthesia after injection is wider than that of ordinary people.
Notice
The concentration of the medicinal solution, the injection speed, and the patient's position can also have a certain impact, but the impact is not significant.
complication
Total spinal anesthesia is a serious complication of epidural anesthesia. It occurs when the needle tip penetrates into the subarachnoid space and is not found during epidural anesthesia or sacral anesthesia. Most or all of the local anesthetic is accidentally injected into the subarachnoid space. A phenomenon in which all spinal nerves are blocked
Clinical manifestations: Dyspnea, blood pressure drops, loss of consciousness, and respiratory arrest occur within a few minutes after injection.
Treatment principle: Immediate artificial ventilation to maintain circulatory function
Indications and Contraindications
It can be used for various abdominal, waist and lower limb surgeries up to the diaphragm and is not limited by the operation time.
It is also used for neck, upper limb and chest wall surgeries, but the anesthesia operation and management techniques are more complicated and should be used with caution.
sacral block
sellar area anesthesia
body position
Keep the patient in a supine position during puncture
Puncture gap
L₄～L₅
anesthetic injection
subarachnoid space
block nerves
sacrococcygeal nerve
belong
Spinal anesthesia (subarachnoid anesthesia, spinal anesthesia)
Indications
Anal, perineal surgery
Common complications
Headache, cauda equina syndrome, postoperative urinary retention
sacral anesthesia
body position
During puncture, the patient should be in the lateral or prone position
Puncture gap
sacral hiatus
anesthetic injection
epidural space
block nerves
sacral nerve
belong
Hard bed external anesthesia
Indications
Rectal, anal and perineal surgery
Common complications
Toxic reactions, total spinal anesthesia, postoperative urinary retention
Comparison of Several Commonly Used Anesthesia Methods
Spinal numbness
injection site
subarachnoid space
Commonly used drugs
Procaine, Cadine, Bupivacaine
Plane adjustment
Dosage (most important), body position (important), puncture gap, injection speed
intraoperative complications
Drop in blood pressure, bradycardia, respiratory depression, nausea and vomiting
Postoperative complications
Headache, urinary retention, cranial nerve palsy, adhesive arachnoiditis, cauda equina syndrome, purulent meningingitis
continuous epidural anesthesia
injection site
epidural space
Commonly used drugs
lidocaine, tetracaine, bupivacaine, ropivacaine
Plane adjustment
Local anesthetic volume, puncture gap, catheter direction, injection method, patient condition, solution concentration
intraoperative complications
Drop in blood pressure, bradycardia, respiratory depression, nausea and vomiting, total spinal anesthesia, local anesthetic toxicity
Postoperative complications
Urinary retention (rare), spinal nerve root injury, epidural hematoma, epidural abscess
sacral anesthesia
injection site
sacral canal
Commonly used drugs
lidocaine, bupivacaine
Plane adjustment
Measurement, body position
intraoperative complications
Total spinal anesthesia, local anesthetic toxicity
Postoperative complications
Urinary retention (most common)