-
Categories
-
Pharmaceutical Intermediates
-
Active Pharmaceutical Ingredients
-
Food Additives
- Industrial Coatings
- Agrochemicals
- Dyes and Pigments
- Surfactant
- Flavors and Fragrances
- Chemical Reagents
- Catalyst and Auxiliary
- Natural Products
- Inorganic Chemistry
-
Organic Chemistry
-
Biochemical Engineering
- Analytical Chemistry
-
Cosmetic Ingredient
- Water Treatment Chemical
-
Pharmaceutical Intermediates
Promotion
ECHEMI Mall
Wholesale
Weekly Price
Exhibition
News
-
Trade Service
Yesterday, I had a new understanding and decision about the weight ratio.
.
.
I got off the night shift.
I'll sort it out now o(*￣︶￣*)oOK Start with clinical anesthesiology 2nd edition P116 wrote that the specific gravity of cerebrospinal fluid is 1.
003 ~1.
009, there are certain individual differences.
Therefore, only when the specific gravity of the local anesthetic liquid is significantly different from that of the cerebrospinal fluid, can the actual impact of the specific gravity be reflected
.
According to the difference between the specific gravity of the local anesthetic and the specific gravity of the cerebrospinal fluid, the local anesthetic can be formulated into light specific gravity, equal specific gravity and heavy specific gravity
.
Equal specific gravity is seldom used at present due to the troublesome preparation and uncertain plane
.
The specific gravity is generally prepared by adding appropriate 5%~10% glucose to the local anesthetic, so that the specific gravity of the liquid (after mixing) can reach more than 1.
020
.
The anesthetic effect of the heavy specific gravity solution is precise, and the anesthesia range is easy to adjust.
It is the most commonly used subarachnoid space blocking liquid in clinical anesthesia
.
The light specific gravity liquid is made by diluting the local anesthetic with a large amount (6-16ml) of water for injection
.
P1152 of the 4th edition of Modern Anesthesiology wrote that the specific gravity of gravity is greater than that of cerebrospinal fluid, and it is easy to sink and spread caudally.
It is often achieved by adding 5% glucose solution
.
Light specific gravity may result in too high a plane.
Currently it is rarely used
.
Morgan Anesthesiology 5th ed.
P687 Writes Factors Affecting Block Plane After Subarachnoid Anesthesia
.
Among them, the most important influencing factors are the specific gravity of the drug solution, the patient's position at the time of injection and immediately after the injection, and the drug dose
.
In general, the higher the anesthetic dose, the higher the injection site, and the higher the obtained plane
.
In addition, the cephalad diffusion of local anesthetics in the CSF depends on its specific gravity relative to the CSF
.
The specific gravity of CSF at 37° is 1.
003~1.
008
.
Heavy-weight local anesthetics are denser (heavier) than CSF, while light-weight local anesthetics are less dense (lighter) than CSF
.
Therefore, when the head is down, the heavier gravitational solution diffuses rostral, while the hypogravimetric solution caudal
.
Head high is the opposite
.
In the lateral decubitus position, the effect of the heavy-gravity spinal anesthesia is stronger on the supporting side (lower side), while the light-weight is on the non-supporting side (upper side)
.
Isogravic solutions can be maintained at injectable levels
.
Mixing (at least 1:1) of the anaesthetic with CSF can make the solution an isobaric solution
.
Other factors that affect the nerve block plane include injection site, patient height, and spinal anatomy
.
The needle bevel or the orientation of the injection port also plays an important role, as cephalad injections can achieve a higher plane than lateral and caudal dominance
.
Miller Anesthesiology 7th Edition P1636 writes 1.
The density of any solution refers to the weight of 1 ml of the solution at room temperature, the specific gravity is the ratio of the densities of the solution to water, and the baricity is the ratio of the densities of the two solutions
.
If the other solution happens to be water, the specific gravity ratio is the same as the specific gravity
.
2.
To obtain a low specific gravity liquid for CSF, the liquid density must be lower than that of cerebrospinal fluid, with a specific gravity ratio slightly below 1.
0000 or a specific gravity slightly below 1.
0069 (average CSF specific gravity)
.
Miller Anesthesiology 8th Edition P1528 writes 1.
Heavier than specific solution diffusion is more predictable, with less patient-to-patient variability
.
2.
The density of cerebrospinal fluid is 1.
00059g/L
.
(Different from the previous version) 3.
Glucose and sterile saline can be added to the local anesthetic solution respectively to make it a heavy or light specific gravity solution
.
4.
The clinical importance of the specific gravity ratio is to influence the ability of the local anesthetic to diffuse and distribute by gravity
.
The heavy specific gravity solution will first diffuse to the recumbent side of the spinal canal, and the hypospecific gravity will diffuse to the ambulatory side
.
5.
In addition, the book also talks about the change of temperature on density, such as 0.
5% bupivacaine at 24° for equal specific gravity, and 37° for light specific gravity
.
An increase in temperature reduces the density of the solution
.
Massachusetts General Hospital Clinical Anesthesia Handbook 9th Edition P294 writes 1.
Compared with CSF (1.
004~1.
007g/ml), local anesthetics can be divided into heavy specific gravity, hypo specific gravity and iso specific gravity
.
2.
Gravity ratio: usually prepared by adding glucose to local anesthetics
.
Due to the specific gravity, the liquid medicine flows to the lowest point of the CSF
.
3.
Light specific gravity: prepared with local anesthetic and sterile water for injection
.
The liquid medicine flows to the highest point of the CSF
.
4.
Equal specific gravity: The advantage is that it can predict the diffusion of the liquid in the CSF without being affected by the patient's position
.
Changes in the patient's position can limit or increase the spread of the drug solution
.
OK, let me summarize the difference between specific gravity and specific gravity ratio.
Heavy specific gravity is added with sugar, and light specific gravity is generally added to more than 6ml of sterile water for injection to be called light! Be careful not to 0.
9% salt water! Specific gravity ratio = denominator: local anesthetic concentration % * local anesthetic taken out ml + solution percentage % * taken out solution volume ml / numerator: taken out local anesthetic ml + taken out solution volume ml plus 1 for example: 1% rope 1.
5ml + 1.
5ml The specific gravity ratio of sterilized water for injection is 1.
005.
In fact, it is not the light specific gravity we often say, but the equal specific gravity! The specific gravity ratio of 1% ropiper 1.
5ml+1.
5ml of normal saline is 1.
009.
In fact, it is not a light specific gravity, nor an equal specific gravity, but a heavy specific gravity! There is a lot of talk about the ratio of specific gravity, some say good and some bad, we can observe it clinically, and we can discuss it together~ I recommend a small program that can calculate the specific gravity ratio called anesthesia helper.
You can search and download it.
Some formulas are still very useful~so In a word, what you think is not real, you are welcome to leave a message and discuss~
.
.
I got off the night shift.
I'll sort it out now o(*￣︶￣*)oOK Start with clinical anesthesiology 2nd edition P116 wrote that the specific gravity of cerebrospinal fluid is 1.
003 ~1.
009, there are certain individual differences.
Therefore, only when the specific gravity of the local anesthetic liquid is significantly different from that of the cerebrospinal fluid, can the actual impact of the specific gravity be reflected
.
According to the difference between the specific gravity of the local anesthetic and the specific gravity of the cerebrospinal fluid, the local anesthetic can be formulated into light specific gravity, equal specific gravity and heavy specific gravity
.
Equal specific gravity is seldom used at present due to the troublesome preparation and uncertain plane
.
The specific gravity is generally prepared by adding appropriate 5%~10% glucose to the local anesthetic, so that the specific gravity of the liquid (after mixing) can reach more than 1.
020
.
The anesthetic effect of the heavy specific gravity solution is precise, and the anesthesia range is easy to adjust.
It is the most commonly used subarachnoid space blocking liquid in clinical anesthesia
.
The light specific gravity liquid is made by diluting the local anesthetic with a large amount (6-16ml) of water for injection
.
P1152 of the 4th edition of Modern Anesthesiology wrote that the specific gravity of gravity is greater than that of cerebrospinal fluid, and it is easy to sink and spread caudally.
It is often achieved by adding 5% glucose solution
.
Light specific gravity may result in too high a plane.
Currently it is rarely used
.
Morgan Anesthesiology 5th ed.
P687 Writes Factors Affecting Block Plane After Subarachnoid Anesthesia
.
Among them, the most important influencing factors are the specific gravity of the drug solution, the patient's position at the time of injection and immediately after the injection, and the drug dose
.
In general, the higher the anesthetic dose, the higher the injection site, and the higher the obtained plane
.
In addition, the cephalad diffusion of local anesthetics in the CSF depends on its specific gravity relative to the CSF
.
The specific gravity of CSF at 37° is 1.
003~1.
008
.
Heavy-weight local anesthetics are denser (heavier) than CSF, while light-weight local anesthetics are less dense (lighter) than CSF
.
Therefore, when the head is down, the heavier gravitational solution diffuses rostral, while the hypogravimetric solution caudal
.
Head high is the opposite
.
In the lateral decubitus position, the effect of the heavy-gravity spinal anesthesia is stronger on the supporting side (lower side), while the light-weight is on the non-supporting side (upper side)
.
Isogravic solutions can be maintained at injectable levels
.
Mixing (at least 1:1) of the anaesthetic with CSF can make the solution an isobaric solution
.
Other factors that affect the nerve block plane include injection site, patient height, and spinal anatomy
.
The needle bevel or the orientation of the injection port also plays an important role, as cephalad injections can achieve a higher plane than lateral and caudal dominance
.
Miller Anesthesiology 7th Edition P1636 writes 1.
The density of any solution refers to the weight of 1 ml of the solution at room temperature, the specific gravity is the ratio of the densities of the solution to water, and the baricity is the ratio of the densities of the two solutions
.
If the other solution happens to be water, the specific gravity ratio is the same as the specific gravity
.
2.
To obtain a low specific gravity liquid for CSF, the liquid density must be lower than that of cerebrospinal fluid, with a specific gravity ratio slightly below 1.
0000 or a specific gravity slightly below 1.
0069 (average CSF specific gravity)
.
Miller Anesthesiology 8th Edition P1528 writes 1.
Heavier than specific solution diffusion is more predictable, with less patient-to-patient variability
.
2.
The density of cerebrospinal fluid is 1.
00059g/L
.
(Different from the previous version) 3.
Glucose and sterile saline can be added to the local anesthetic solution respectively to make it a heavy or light specific gravity solution
.
4.
The clinical importance of the specific gravity ratio is to influence the ability of the local anesthetic to diffuse and distribute by gravity
.
The heavy specific gravity solution will first diffuse to the recumbent side of the spinal canal, and the hypospecific gravity will diffuse to the ambulatory side
.
5.
In addition, the book also talks about the change of temperature on density, such as 0.
5% bupivacaine at 24° for equal specific gravity, and 37° for light specific gravity
.
An increase in temperature reduces the density of the solution
.
Massachusetts General Hospital Clinical Anesthesia Handbook 9th Edition P294 writes 1.
Compared with CSF (1.
004~1.
007g/ml), local anesthetics can be divided into heavy specific gravity, hypo specific gravity and iso specific gravity
.
2.
Gravity ratio: usually prepared by adding glucose to local anesthetics
.
Due to the specific gravity, the liquid medicine flows to the lowest point of the CSF
.
3.
Light specific gravity: prepared with local anesthetic and sterile water for injection
.
The liquid medicine flows to the highest point of the CSF
.
4.
Equal specific gravity: The advantage is that it can predict the diffusion of the liquid in the CSF without being affected by the patient's position
.
Changes in the patient's position can limit or increase the spread of the drug solution
.
OK, let me summarize the difference between specific gravity and specific gravity ratio.
Heavy specific gravity is added with sugar, and light specific gravity is generally added to more than 6ml of sterile water for injection to be called light! Be careful not to 0.
9% salt water! Specific gravity ratio = denominator: local anesthetic concentration % * local anesthetic taken out ml + solution percentage % * taken out solution volume ml / numerator: taken out local anesthetic ml + taken out solution volume ml plus 1 for example: 1% rope 1.
5ml + 1.
5ml The specific gravity ratio of sterilized water for injection is 1.
005.
In fact, it is not the light specific gravity we often say, but the equal specific gravity! The specific gravity ratio of 1% ropiper 1.
5ml+1.
5ml of normal saline is 1.
009.
In fact, it is not a light specific gravity, nor an equal specific gravity, but a heavy specific gravity! There is a lot of talk about the ratio of specific gravity, some say good and some bad, we can observe it clinically, and we can discuss it together~ I recommend a small program that can calculate the specific gravity ratio called anesthesia helper.
You can search and download it.
Some formulas are still very useful~so In a word, what you think is not real, you are welcome to leave a message and discuss~
