WEEK 6B - Anaesthetic Emergencies Flashcards
(13 cards)
Describe the causes of high or total spinal block
May occur from an excessive spread of local anaesthetic administered intrathecally, extradurally, or subdurally , inappropriately high doses of medication, poor positioning (supine - think gravity)
Describe the causes of local anaesthetic toxicity
When local anaesthetic drugs are accidentally injected or absorbed into the intravascular space in toxic amounts, resulting in CNS and cardiovascular compromise
Occurs during spinal or epidural or during infiltration before an episiotomy
Describe failed intubation and its causes
The inability to successfully intubate the trachea after two attempts, despite optimal positioning and use of the adjunctive techniques, with a third attempt undertaken only by an experienced anaesthetist
Describe the management of total spinal block
Stop infusion and L) lateral tilt / ABC resuscitation & IV fluids
Immediate presence of anaesthetist who can diagnose and treat this (CODE BLUE) complication with necessary equipment (epidural trolley)
Establish an airway - tracheal intubation
Ventilation with oxygen
Ephedrine or phenylephrine
Describe the management of high block
Stop infusion
Sit up-right
Complete dermatomes and full set of obs
Monitor airway
Anaesthetic review
Provision of cardiovascular support
Fluids and vasopressors administered to maintain maternal haemodynamic stability and provide adequate utero-placental perfusion to the foetus
Describe the clinical presentations of local anaesthetic toxicity
Lightheadedness
Tinnitus
Numbness of tongue
Seizures and unconsciousness
Coma and respiratory arrest
Cardiovascular depression
Describe the management of local anaesthetic toxicity
Stop injecting immediately
Emergency buzzer
Maintain the airway, and if necessary, secure with tracheal tube
Give 100% oxygen and ensure adequate lung ventilation
Establish IV access
Control seizures - small doses of benzodiazepine, propofol or thiopental
Intralipid 20%
Describe the maternal implications of failed intubation
Anatomical changes in pregnancy such as increased adipose tissue, pharyngeal and laryngeal oedema, large tongue, and enlarged breasts results in difficult laryngoscopy. FRC is reduced in pregnancy and in supine position. High BMI concerns
Increased volume and acidity of gastric contents, and raised intra-abdominal pressure can cause difficulty intubating
Higher incidence of maternal awareness due to fear of oversedation of the fetus and reduced contractility of the uterus
Describe the neonatal implications of failed intubation
Placental transfer of general anaesthetic drugs can cause lower APGAR scores in neonates
Fetal distress due to general anaesthesia - especially when foetus may already be distressed
Neonatal respiratory depression
Prolonged maternal hypoxia can occur during failed intubation, which may adversely affect neonatal neurological outcome
Describe the diagnosis and management of failed intubation
Evaluation of the airway must be performed prior to administering GA
Cardiovascular history
Current haemoglobin and confirmation of a valid group is important
Management:
Maximum of two attempts, with a third only by an experienced colleague
If inadequate:
Declare a failed intubation and call for help
Maintain oxygenation with 100% oxygen
Insert a supraglottic airway device
Or Facemask ventilation
If inadequate again:
Administer 100% oxygen
Perform front of neck access (via scalpel)
Describe the potential outcomes of spinal block
Can lead to profound hypotension, dyspnoea, inability to speak, and loss of consciousness
Foetal compromise in response to maternal compromise
Increased risk of c/s or instrumental
Describe the stabilisation and treatment of local anaesthetic toxicity
In circulatory arrest:
- Start CPR
- Manage arrhythmias using the same protocols
- Consider the use of cardiopulmonary bypass if available
- Give intravenous lipid emulsion
- Continue CPR throughout treatment with lipid emulsion
Without circulatory arrest:
- Use conventional therapies to treat hypotension, bradycardia and tachyarrhythmia
- Consider intravenous lipid emulsion
Describe the potential outcomes of local anaesthetic toxicity
Later signs of LA toxicity include: tonic-clonic seizures, altered mental state/confusion, arrhythmias, bradycardia, asystole, hypotension, coma, respiratory arrest, cardiac arrest
Outcome depends on when the toxicity is detected and managed
