Authors: Jonny Devaney / Code: C3AP6, CAP23, CAP35 / Published: 02/02/2016
Procedural sedation is an amazingly useful skill to have, but it is not without its perils. Listen to our podcast for some tips on how to get started or to improve your practice.
All in all, if we careful in our preparations, sedation is very safe, but this also includes preparing for things that might go wrong. When we thing about getting ready for a sedation, it raises several important process issues that are relevant to any procedure that we might be carrying out in the emergency department.
Firstly we must decide if this patient needs a sedation; is this a procedure that can be safely done under local anaesthetic? Will it be so complex and invasive that it can only be done under a general anaesthetic?
Once we are happy that this is the case we next have to ask ourselves if this is the right patient.
During a sedation we are giving some pretty powerful drugs with some fairly dangerous side effects. There are some good tools that we can use to decide if this patient is appropriate to be sedated in the department
Anything that is either a grade I or II is suitable for sedation in the department. Anything greater than grade III is probably more risky than is sensible to carry out in the department. An alternative should be considered; such regional local anaesthetic techniques or general anaesthetic.
Next we must decide if the department is in appropriate state to be carrying out a procedure that will eat up staff, space and resources. This might sound relatively trivial, but a perfectly safe procedure can very quickly become unsafe, or render a whole department unsafe, if carried out when it is not appropriate.
Can a space be provided in the resuscitation are or somewhere with equally sufficient equipment? Can you spare the staff? Namely a sedation doctor, a trained clinician (or possibly more) for the procedure, and an experienced nurse to assist with the sedation. If the answer to this is no, we must consider again of this procedure can be deferred or an alternative sought. If not, then the department must be made safe for the procedure.
The next piece of preparation is the assessment of the patient. This will obviously involve a thorough history of their past medical history, anaesthetic history (including familial history of complications) and fasting history. At this stage the patient should be formally consented.
Since many of the drugs may obtund the airway, it is essential that the airway be assessed so that we are prepared to take control of an airway, and if necessary, ventilation.
Again there are many tools to assess this, the most commonly used is the acronym LEMON
Look – observe the head and neck. Are there any features that may make the intubation more difficult? Such as craniofacial abnormalities, no teeth or beards
Evaluate – this is the 3 – 3 – 2 rule; there should be 3 finger breadths of space when they open their jaw, 3 from their hyoid to the tip of their jaw and 3 finger breadths between their thyroid and hyoid.
It is also a good idea to check if their jaw can protrude so that the patient’s lower incisors overlap their upper incisors.
Obstruction – is there anything that is likely to obstruct the view or the airway itself? Such as burns, blood, trauma, secretions or vomitus.
Neck – can the neck be freely and safely extended? Ideally the tip of the jaw should extend past the tip of the occiput
No tool will definitively predict a difficult airway, but with a through assessment, cautious preparation and good training difficulty can be avoided or worked around.
The next step will be the selection of the agent. Each of the drugs mentioned here have their own benefits and risks, and this is only the briefest of overviews about them and their usage. A considerable amount of reading and supervised experience with them is recommended.
When considering the drug, we must consider the state of the patient and the nature of the procedure. An elderly patient will be more at risk from a cardiovascularly depressant drug like propofol. Or a procedure may take slightly longer and require a drug with a longer duration. There is no easy answer to this, and a good history combined with good clinical acumen are essential.
Checking your procedure are prior to the procedure is essential. There should be suction, a table capable of head-down tilt, a fully stocked airway trolley – including intubation kit. Resuscitation equipment should be readily available.
The patient should have IV access connected to a bag of saline to allow rapid flushing of the drug and ensure the line is patent.
Minimal monitoring equipment is oxygen saturation probe, blood pressure monitoring, ECG monitoring and CO2 trace.
Once we are ready to begin the sedation we must decide on the appropriate level to aim for.
- Minimal – anxiolysis
- Moderate – purposeful response to verbal or tactile stimulus
- Deep – purposeful response to repeated or painful stimulus
- General anaesthetic – totally unto unrousable
Ideally a procedure should be carried out with the minimal level of sedation required to get cooperation and minimise distress from the patient. Some procedures will require deeper levels, for example a reduction of a dislocated hip will certainly need a deeper level of sedation. However, as deeper and deeper sedation is achieved it becomes harder to tell the difference between sedation and a general anaesthetic. And following the removal of the painful stimulus of the dislocation, it can be easy to slip down into a deeper level following a reduction and this should be carefully observed and prepared for.
Once the procedure is completed, the patient may be removed from the procedure area once they are physiologically normal, supporting their own airway, breathing and circulation. They can be discharged once they are fully alert, mobilising at a baseline level and their analgesia is controlled. They should only go home in the care of a responsible adult, with written post sedation instructions and follow-up details.
We hope you enjoyed the podcast and use this to continue to improve your sedation technique in the future.
- ACEP 2014 Clinical Policy on Sedation
- Reuben Strayers Trilogy on Procedural Sedation
- EMCrit on Procedural Sedation
- Miner JR, Gray RO, Stephens D, Biros MH. Randomized clinical trial of propofol
with and without alfentanil for deep procedural sedation in the emergency
department. Acad Emerg Med. 2009 Sep;16(9):825-34 PMID 19845550