General anaesthetic or Sedation?
A general anaesthetic is where you are asleep
And not aware of what is going on.
We can all agree on that.
So what is sedation?
The simple answer is that it is somewhere in between being completely asleep and completely awake.
The complex answer takes a bit of time to explain, if you are interested.
However, within the simple answer above, its clear that sedation is not a single state. Its a continuum.
And not aware of what is going on.
We can all agree on that.
So what is sedation?
The simple answer is that it is somewhere in between being completely asleep and completely awake.
The complex answer takes a bit of time to explain, if you are interested.
However, within the simple answer above, its clear that sedation is not a single state. Its a continuum.
Its not a strange as it sounds. In the operating theatre, there are 3 players: The Patient, The Surgical team and The Anaesthetic team and all must be on the same page. The patient, the surgeon and the anaesthetist must all be clear about where on the continuum the patient will be before starting the operation and what to do if more, or less sedation, is required than expected. While the patient is at the centre of what we do, once in theatre, it takes 3 to create a successful procedure.
If the operation is larger, or the area to be injected is sensitive, such as with a face lift then some intravenous sedation can be useful. This involves giving drugs in through a vein. Small amounts can be given by the doctor doing the procedure, but only small amounts, as the doctor needs to concentrate on the procedure and not on the effects of the sedation.
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To safely give a significant amount of intravenous sedation, where there is a chance that the patient can not reliably respond appropriately to commands, there must be a person able to monitor and manage the airway breathing and circulation. This is deep sedation, which is deeper than normal sleep. Usually you would wake up if you were just asleep during a face lift. Hence deep sedation can appear to be like general anaesthesia.
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The surgeon needs the patient to be still and calm. How still and how calm depends on the surgery and the patient. A slow pulse and normal blood pressure mean there is less bleeding, less bruising, the operation is easier and may give better results. Every operation and every patient is different, so the level of sedation needs to be considered for every patient.
A general anaesthetic for everyone makes the decision making process easy but:
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As you can now see, there are lots of different things to consider when deciding how deeply sedated someone needs to be for a successful procedure and there are 4 broad areas:
- No sedation: Talking, aware, will remember
- Conscious sedation: Talking, aware, may or may not remember
- Deep sedation: Not talking, may be aware, probably wont remember
- General anaesthesia: Not talking, not aware, will not remember
Many operations can be done under conscious sedation, if the patient is keen to minimise the effects of sedation, the surgeon wants the operative area to be as natural as possible and the anaesthetist or sedationist is able to provide it.
Here is another way to describe the sedation continuum, if you like a visual structure.
I have divided conscious sedation into light and deeper, which gives 5 possible overlapping categories.
I have divided conscious sedation into light and deeper, which gives 5 possible overlapping categories.
These categories are a guide only, there is overlap between them and the descriptions cannot be relied on absolutely. The aim is to provide a useful structure.
The only way to guarantee that patients will not remember the proceedure is for general anaesthesia.
If the resources outlined above for Deep sedation or General Anaesthesia are not available, then the patients must be counselled appropriately and expect conscious sedation.
Care Quality Commission (CQC) requirements differ significantly between conscious sedation (column 3) and deep sedation (column 4). Primarily because the difference between deep sedation (column 4) and general anaesthesia (column 5) is not clear and deep sedation can easily tip into general anaesthesia with a slight overdose.
Therefore deep sedation should be resourced as for general anaesthesia as there is a very real risk of deep sedation becoming general anaesthesia
The key point is about the aim of the sedation.
If the aim is for the patient to be deep enough not to respond to commands, then its deep sedation or general anaesthesia and all the resources that this requires.
If the aim is for the patient to respond appropriately to commands throughout, then this is conscious sedation.
And may be the difference between a sedationist and an anaesthetist is in the plan for what to do if the patient becomes deeper than expected or desired.
In sedation the plan is usually to stop giving anything and allow the patient to wake up.
In anaesthesia the plan is usually to give more and take over control of the the patients airway, breathing and circulation if required.
Abbreviations:
SV: Spontaneous Ventilation. Breathing under patient's control
IPPV: Intermittent Positive Pressure Ventilation. Breathing under mechanical control.
SpO2: O2 saturations in the blood
ECG: Electrocardiogram
NIBP: Non invasive blood pressure
ETCO2: End tidal CO2
FiO2: Fraction of inspired O2
ETCO2: End tidal Anaesthetic agent
The only way to guarantee that patients will not remember the proceedure is for general anaesthesia.
If the resources outlined above for Deep sedation or General Anaesthesia are not available, then the patients must be counselled appropriately and expect conscious sedation.
Care Quality Commission (CQC) requirements differ significantly between conscious sedation (column 3) and deep sedation (column 4). Primarily because the difference between deep sedation (column 4) and general anaesthesia (column 5) is not clear and deep sedation can easily tip into general anaesthesia with a slight overdose.
Therefore deep sedation should be resourced as for general anaesthesia as there is a very real risk of deep sedation becoming general anaesthesia
The key point is about the aim of the sedation.
If the aim is for the patient to be deep enough not to respond to commands, then its deep sedation or general anaesthesia and all the resources that this requires.
If the aim is for the patient to respond appropriately to commands throughout, then this is conscious sedation.
And may be the difference between a sedationist and an anaesthetist is in the plan for what to do if the patient becomes deeper than expected or desired.
In sedation the plan is usually to stop giving anything and allow the patient to wake up.
In anaesthesia the plan is usually to give more and take over control of the the patients airway, breathing and circulation if required.
Abbreviations:
SV: Spontaneous Ventilation. Breathing under patient's control
IPPV: Intermittent Positive Pressure Ventilation. Breathing under mechanical control.
SpO2: O2 saturations in the blood
ECG: Electrocardiogram
NIBP: Non invasive blood pressure
ETCO2: End tidal CO2
FiO2: Fraction of inspired O2
ETCO2: End tidal Anaesthetic agent