Anaesthesia Points to Remember
Beware of conus injuries from needling the spinal cord during spinal anaesthesia. It can lead to lifelong disability and pain. Once you insert your spinal needle more than one space above a line joining the iliac crests then the risks start to escalate.
Maintain adequate levels of blood pressure during anaesthesia. Hypotension under anaesthesia continues to be associated with increased morbidity and mortality. Patient age and co-morbidities should influence the minimum acceptable blood pressure.
The recommended dose of morphine for an IV PCA should not be greater than 1 mg with a 5 minute lockout, except in opiate dependent patients.
There is no point giving a test dose of antibiotic IV unless you perform minute dilutions into one litre of crystalloid and run it into the patient slowly.
Blood needs to be carefully checked to ensure the correct patient is receiving the correct blood. Errors continue to occur. Mismatched blood transfusion carries a high mortality rate.
When injecting significant amounts of LA it is recommended to have patients awake and communicative to reduce the likelihood of LA toxicity
Aspiration prior to injection does not rule out being intravascular (the side of the vessel wall can be sucked against the bevel of the needle).
Slow injection of LA is essential while maintaining communication with the patient: “Tell me if you are experiencing anything unusual”.
Longer acting LA’s such as bupivacaine and ropivacaine have a higher incidence of LA toxicity than shorter acting ones such as lignocaine or prilocaine.
LA toxicity with mortality and major morbidity continues to occur.
Laryngeal tumours can create major airway difficulties for anaesthesia with airway obstruction and bleeding
Patients with laryngeal tumours ideally should have an MRI prior to anaesthesia.
Beware of gas trapping with IPPV in patients with respiratory conditions such as asthma and cystic fibrosis. This can lead to cardiovascular collapse. Such patients require reduced respiratory rates and longer I:E ratios to allow sufficient time for gas to be exhaled.
In patients with gastric outlet obstruction be prepared for regurgitation of large volumes of gastric fluid or blood.
Naloxone can precipitate massive sympathetic response with pulmonary oedema. Giving divided doses may diminish this effect.
Take care not to have malleable stylets protruding out the end of ETTs as they can also cause tracheal damage.
Jet ventilation must be used with considerable caution as surgical emphysema and pneumothoraces have been frequently reported. Care must be taken to ensure the upper airway is not obstructed. Gas needs to be able to get out as well as get in.
TIVA continues to be associated with awareness under anaesthesia.
Gas insufflation at laparoscopy can cause asystole or profound bradycardia. Careful monitoring is required. Treatment may require allowing the gas to escape rapidly.
Negative pressure pulmonary oedema may occur following emergence from anaesthesia in younger patients. CPAP or IPPV will usually be required.
Syringe swap continues to cause problems. Take extra care with muscle relaxants and vasopressors.
If your patient is hypotensive consider anaphylaxis, particularly if you have given muscle relaxants or antibiotics. There are many case reports of patients receiving significant doses of metaraminol and ephedrine prior to anaesthetists starting definitive treatment of anaphylaxis with adrenaline.
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