Preparing for Emergence 🛬
Emergence is the second-busiest time after induction. The aim is to have the patient conscious, pain-free and with near-normal physiology, including…
- Spontaneous breathing
- No supplemental oxygen requirement
- Normal temperature
- Blood pressure within 20% of where it was on induction
- No ongoing need for vasopressors or inotropes
Reversing Muscle Relaxation 💪
Suxamethonium cannot be reversed but it’s short-acting so we don’t bother.
The non-depolarising muscle relaxants can be reversed using a combination of anticholinesterase and anti-muscarinic agents.
Conventional Reversal
Non-depolarising muscle relaxants work by out-competing acetylcholine (ACh) for binding sites on post-synaptic ACh receptors. ACh is normally broken down by acetylcholinesterase (AChE), an enzyme that lives in the synaptic cleft.
Inhibiting acetylcholinesterase means less ACh is broken down, so more stays in the synaptic cleft to compete with muscle relaxants for binding sites.
Et voila, muscle function returns!
Cholinesterase inhibitors also cause ACh to accumulate in the paraympathetic nervous system, which will cause significant bradycardia and hypotension. We counter-act this unwanted effect by co-administering an anti-muscarinic agent like atropine or glycopyrolate.
Sugammadex
Sugammadex is a tubular molecule that traps rocuronium and vecuronium in its core, thus preventing their action on the post-synaptic ACh receptors.
It’s very expensive, so it should only be used for urgent reversal of profoundly paralysed patients. More details are available in the Nerd Box.
Are They Awake? 👀
There are no antidotes for the commonly-used maintenance agents. We turn them off and wait for them to “wash out”, which takes a few minutes.
Patients are generally considered “awake” if they can obey verbal commands like “open your eyes” or “squeeze my hand”. If they’re pulling at their still-in-place endotracheal tube, they’re up.
Extubation 🙊
Extubation is risky because any patient can laryngospasm, aspirate or become apnoic without warning. The ideal patient to extubate is…
- Adequately fasted
- Haemodynamically stable
- Easy to re-intubate
- Adequately oxygenated
- No longer paralysed
- Breathing spontaneously
- Awake enough to obey commands
If the patient tries to pull the tube out by themselves, help them.
We bend (and break) these rules all the time. Once the risk of airway emergency is acceptably low, it’s time to pull the tube…
- Pre-oxygenate (again)
- Insert a bite block
- Suction the airway with your Yankauer sucker
- Raise the bed to a semi-recumbent position
- Double-check that they’re reversed and awake enough
- Inflate the lungs (so they can cough the secretions out)
- Deflate the cuff and gently pull the tube out
- Monitor for apnoea
Now call for a porter start heading to PACU.
Nausea and Vomiting 🤮
Surgery and anaesthetic medications make patients want to vomit. The risk factors for post-operative nausea and vomiting (PONV) are…
- Demographic
- Young
- Female
- Non-smoker
- Anaesthetic
- Volatile anaesthetics
- Nitrous oxide
- Opioids
- Surgical
- Inner ear
- Gynaecological
- Laparoscopic
- History
- Prior PONV
- Motion sickness
The Apfel score is commonly used to estimate the risk of PONV.
Management
We give a range of anti-emetics from different classes. Good rule of thumb: count up their Apfel score and give that many anti-emetics.
Handover to PACU 🏈
The post-anaethetic care unit (“PACU” or “recovery ward”) is staffed by specialist nurses who monitor and manage post-operative patients one-to-one.
A structured handover between anaesthetists and PACU nurses ensures safety and efficiency. Consider presenting a few of your patients using this structure, loosely based on the ISOBAR system…
- Indentify
- Yourself
- The patient
- Surgical situation
- Type of operation
- Drains
- Catheters
- Blood loss
- Surgeons’ instructions
- Anaesthetic situation
- Type of anaesthetic
- Amount of opioid given
- Anti-emetics given
- Reversal method
- Problems during anaesthesia
- Observations
- Wait for the nurses to do one set of observations
- Highlight any persisting physiological issues
- Relevant medical background
- Plan
- Analgesia plan
- Where they’re going after recovery
- Anything you need done (blood tests)
- How to contact the anaesthetist
Now head for the tea room.