Analgesia/Anaesthesia Module 1 Flashcards
How does a GDV cause pain?
Torsed stomach…
1. fills with fluid –> leads to dehydration
2. Expands and puts pressure on the diaphragm –> loss of functional residual capacity and decreased tidal volume - diaphragm movement is impeded
3. Increased the abdominal pressure and decreases the venous return to the heart and leads to decreased CO
4. Pain causing catecholamines to release - which angers myocardium (pro-arrhythmic)
Derogating spleen can cause release of further inflammatory factors further angering the myocardium –> this releases myocardium depressant factor as the spleen gets its blood supply
What drugs should be avoided during a GDV
ACP - CO drops by 20% & drops BP and PCV drops by 10%
Good for surgeries where there is a lot of blood as can hide from the surgeon
How will low protein affect anaesthetic drugs?
If protein low most anaesthetic drugs are lipophilic so. Normal dr dose will cause a relative overdose and means lots of free drug swimming about and will take longer to recover
Outline the steps for placing a central line
- 11 blade - tent and puncture the skin
- 18g cannula - never stop raising till everything is clamped off - will suck air into the jugular
- Wire through the catheter - stop advancing if VPC - never let go of the wire
- Thread catheter over the wire
- Thread over the dilator and put in and then take off
- Run the line in over the wire
- Suture into place on butterfly areas
- Pull out wire
- Aspirate blood through each lumen to dispel air
- Always stop infusions when aspirating
Premedication and stabilisation protocol for GDV
- 0.5mg/kg IM methadone
- 2x pink catheters for blood samples + fluids
- Pre-oxygenate
- Correct shock with fluids
- Blood products if bleed suspected
- Anaesthetic safety checklist
*if O2 30mmHg or lower - means the body is increasing the fractional O2 usage to compensate for hypoxaemia
Induction and maintenance of GDV
MAC - depends on noxious stimuli
Co-anaesthetic infusion with lido/fentanyl (may need glycopyrolate to combat drop in heart rate)
- Lido - helps maintain blood gut barrier, decreases active neutrophils and helps with VPCs
BP dropping due to vasodilation- noradrenaline
Bupivicaine line block down the incision
Alfaxalone - 0.5-0.25mg/kg IV + midaz (0.4mg/kg or 0.2mg/kg if already heavily sedate)
Recover in sternolateral position - sternal TL and lateral HL
Post-op care GDV
Things to monitor
O2
Pain
Infusions/boluses of pain
Anti-inflam
Bladder mx
Monitoring
What modalities for anaesthetic monitoring?
- Pulse oximeter
- Capnograph
- Blood pressure
- ECG
- BG analysis
- Blood loss (calculation)
- +/- train of four - if paralytics used
- +/- spirometry
- +/- UOP - ventilated lungs can decrease UOP due to RAAS affected
Premedication and Stabilisation of a pneumothorax
- Rehydration + O2
- Thoracocentesis
- Manual ventilation?
- Pre-clip
- IV fluids
- +/- blood products
Premed: Opoid and pre oxygenate (face mask will double the amount of time to resp failure
How is Train of Four monitored?
- paralytic drugs work to competitively inhibit NM junction
- Ulnar medial nerve used to check depth of the blockade
- Under anaesthetic + NM blocker = central eye + slack jaw
- Getting light - lacrimating, increased RR, - - Increased BP, movement
What are plans for analgesia and recovery from a thoracotomy?
- Ketamine infusion IF no intercostal blocks
- Intercostal nerve block - more dorsal the nerve block = more branches blocked
- Block 3 before infections and 3 caudal
- Through chest drain can be 1mg/kg bupivicaine - can be 5min early but not 5min late
- Daily dose max 4mg/kg
- Single dose max 2mg/kg
What do you have to consider when recovering a thoracotomy patient?
- Oxygen availability
- Pain assessment
- Infusions v. Bolus
- Locoregional wound catheter
- Recover in sternolateral
Monitoring
C-section anaesthetic plan
- Oxygen
- Pain relief - methadone 0.3mg/kg or epudural if planned c-section
- Fluids 10-20ml/kg
- Pre-clip
- Tilt to left (vena cava on right)
- Induction with alfax/propofol
- NSAIDs + paracetamol when puppies are out - okay to go home with
- Leak = abs
- Line block post op
