Crisis and complications Flashcards
What is the ECG criteria for Acute myocardial ischaemia?
- ST segment depression >0.5mm at the J point in >2 contiguous leads
- T wave inversion
- Wellen’s T waves (Deeply inverted or biphasic) in V2-4
What is the ECG criteria for acute myocardial infarction?
- ST elevation in 2 contiguous leads
- > 1mm (all leads other than V2, V3)
- > 2mm in V2 and V3
- NSTEMI
- new ST depression or TWI in 2 contiguous leads
Which leads refer to which part of the heart?
Lateral: I, aVL
Anterior V1-V6
Inferior: II, III, aVF
What is the management of acute myocardial ischaemia?
Aims: 1. Confirm diagnosis. 2. Optomise myocardial oxygen supply and demand
- Confirm diagnosis: Full set of obs, 12 lead ECG, urgent bloods eg trop and Hb
May need serial ECGs
If STEMI -> cath lab
If NSTEMI unstable -> cath lab
If NSTEMI stable, consult cardiology
- Optomise myocardial O2 supply and demand
- Prepare for arrythymias
- A: Maintain Airway
- B: supplemental O2
- C: Treat hypotension, treat anaemia, reduce preload (GTN), aspirin load, short acting beta blockers if tachycardic and can tolerate it
D - treat Pain (analgesia)
Consult cardiology and surgeon
What is oliguria?
<0.5mls/kg/hr or <300-500mls/day
What are risks factors for venous gas embolism?
- Procedures with gas insufflation
- Procedures with open veins that may be at low pressure eg spinal/neurosurg
- Unprimed venous lines during rapid infusion
What are signs of venous gas embolism?
- Tachycardia/arrhythmia
- Decreased BP
- Sudden etCO2
- Increased CVP
- Mill wheel murmur
What is the management of venous gas embolism?
- Inform surgeon and try and stop further entrainment
- Call for help
- Operation site below heart
- 100% FiO2
- Circulation - > treat BP
- Aspirate CVC
- Post op - consider hyperbaric/HDU/ICU/Pt informed/documentation/debriefing
How does venous Co2 gas embolism occur and what is the difference compared to air embolism?
- Direct trocar insertion into a vessell or inadvertent inflation of a solid organ
- Less severe compared to air due to increased solubility and rapid absorption of CO2
How can you recogonise accidental intra-arterial injeciton?
- Pain and discomfort on injection
- Expected physiological response to drug not seen
- Pallor/paraesthesia/hyperaemia of limb distal to injection site
What is the pathophysiology of arterial drug injection injury?
- Arterial spasm due to release of vasoactive substances of direct action of drug
- Risk of drug precipitation and crystal formation with ischaemia and thrombosis
What are the goals of managing inadvertant intra-arterial injection?
- Identify the drug administered to risk stratify
- Maintain perfusion distal to site of injury
- Analgesia
What is the management of inadvertant intra-arterial injection?
- Analgesia: as needed
- Maintain perfusion: consider anticoagulation to prevent thrombosis, elevate arm to improve venous drainage, keep art line in to monitor perfusion to arm
- If prior to operation, observe for period of time and monitor for ischaemia
- If concerns then plastic referral
- Open disclosure
- M+M
- Refer to complication database
What is a useful structure talking about crticial inductions?
-Opening statement labelling it as a critical induction
- Outlining priorities
- Management A -> E
- With C - focus on rate/rhythm/afterload/preload/contractility
- Discuss monitoring/access/drugs for circulation
- Defending sinus rhythm important in some conditions -> with esmolol or shock if unstable
What are the ECG changes with RV strain?
- Dominant R wave V1
- Dominant S wave V6
- ST changes
- Right axis deviation
What are the cardiac aims in cardiac tamponade?
- Maintain SR
- High normal HR - increased filling time won’t help as filling is pressure dependent rather than time
- Increase preload
- Maintain normal Afterload
- Maintain contractility
What are neuroprotective mechanisms?
- A - Avoid coughing/straining
- B - Normal O2 sats, low/normal CO2
- C - normal BP
- D - decreased CMRO2 eg thiopentone, anti-epileptics
- E - Avoid tight neck ties etc, normothermia, head up 30 degrees
- F - Na high normal, normal glucose
What are causes of delayed emergence?
Patient:
- metabolic disturbances eg hypo/hyper Na, hypoglycaemia, Mg, Ca
- Hypothermia
- Coingestion of sedating agents
- Pathology: Seizures, stroke
Anaesthetic:
- Residual anaesthetic
- Residual paralysis
- Opioid narcosis
- Benzodiazepine overdose
- Abnormal vitals eg hypotension, hypoxia
- LAST
Surgical:
- Direct surgical injury to blood supply of brain
- Positioning related injury to neck vessels/blood supply
What are the priorities in a theatre fire?
- Identify and communicate crisis
- Ensure self, patient and staff safety –> evacuate
- contain +/- extinguish fire
What is the management of a fire in theatre area (not intraop)?
- Confirm fire
- Declare crisis
- Extinguish small flames with water and fire extinguisher, remove flammable material such as drapes
- R: rescue, listen to fire warden, evacuate pt with prop infusion, laerdel bag, surgical packing, portable monitoring
- A : Alarm
- C: Confine , shut theatre doors after evacuation, turn off medical gases
- E: extinguish flames using fire extinguisher
- Post review patient for injuries and temporise/complete surgery, review staff for injury
What is awareness?
Explicit awareness is explicit recall of intraoperative events after completion of general anaesthesia
What are risk factors for awareness?
Patient:
- younger adults but not children
- Obesity
- Chronic substance use
- Previous awareness
Anaesthetic:
- Difficult airway
- Use of neuromuscular blockers
- Junior anaesthetic provider
- TIVA
Surgical:
- Emergency surgery
- Cardiac, neurosurgery, obstetric
- Evening/night surgery
What are the strategies to minimise risk of awareness?
- History - explore details of previous awareness, obtain previous anaesthetic records
- Vigilance - check equipment and drugs, give repeat bolus in difficult airways, intraop vigiliance with signs of lightening eg tachycardia/BIS changes
- Anaesthetic technique: benzodiazepine, adequate induction and maintainence doses, depth of anaesthesia monitoring, avoid TIVA, ensure reliable IV access, continous etSevo monitoring, rationalise use of NMB
- Emergence: avoid lightening plane of anaesthesia prior to reversal, use twitcher, use of suggamadex
What are risk factors for PONV?
Patient: - age 3-50, female, non smoker, hx motion sickness, hx of PONV
Anaesthetic: long anaesthetic, volatile anaesthetics, N20, large doses of opioids, emetigenic drugs eg ergometrine, general anaesthetic vs regional
Surgical: types of surgery eg inner ear, neurosurgery, bowel surgery, laparoscopic surgery
