Sicker patients anaesthesia Flashcards
What is the key focus when anesthetizing ASA III-V patients?
Thorough preoperative evaluation & optimisation of patient’s clinical state
Why is different patient monitoring needed for different disease conditions during anesthesia?
Different conditions require specific monitoring to ensure patient safety & optimal physiological function
What monitoring is recommended for a patient with a pre-existing cardiac arrhythmia?
Electrocardiographic (ECG) monitoring during induction, maintenance & recovery
What monitoring is essential for a patient with chronic renal failure under anesthesia?
Arterial blood pressure monitoring to ensure adequate renal perfusion
Why is it important to understand the pharmacology of long-term medications in chronic disease patients undergoing anesthesia?
To avoid drug interactions with anaesthetic & analgesic agents
Should anti-epileptic and endocrine therapy medications be continued before anaesthesia?
Yes, most long-term treatments should be continued as normal
Why can angiotensin-converting enzyme (ACE) inhibitors cause complications in anaesthesia?
They cause vasodilation, which may lead to hypotension, especially if acepromazine is included in anaesthetic protocol
What are some key elements of pre-operative patient evaluation (in sicker patients)?
Clinical evaluation & recent history
Previous GA history
Current medications
Current comorbidities
Temperament/anxiety
Pain assessment
Hydration & oxygenation status
Surgical/diagnostic plan
What are some key elements of perioperative preparation for ASA III-V patients?
Pre-operative blood tests & diagnostics
IV fluid therapy (IVFT) resuscitation
Anti-anxiety medication if needed
Continuation of medications
Pre-placing IV access
Pre-oxygenation
Draining chest/abdomen if necessary
What benefits do pre-anaesthetic blood tests provide for ASA III-V patients?
Help identify abnormalities such as dehydration, electrolyte imbalances & glucose disturbances, allowing for pre-anaesthetic corrections to improve tolerance to anaesthesia
What is a pragmatic approach to pre-anaesthetic blood screening?
Should be performed on older patients (>8) & sick patients
What are the recommended pre-anaesthetic blood tests for sick and older patients?
Packed Cell Volume (PCV)
Total solids
Electrolytes
Glucose
Urea & Creatinine
Why should alpha-2 agonists be avoided in ASA III-V patients?
They can cause significant cardiovascular depression in compromised patients & have narrow therapeutic index (can give low dose of dexmedetomidine if animal is distressed)
What premedication options are commonly used in ASA III-V patients?
Opioids alone (e.g., methadone, butorphanol)
Ketamine & midazolam (IM or IV, not in HCM cats)
Alfaxalone & opioid (can add BZD if needed)
What precautions should be taken during induction of ASA III-V patients?
Don’t leave patient unsupervised after premed
Continue to provide oxygen
IV admin of premed often followed soon by induction drugs
Titrate induction drugs slowly to effect in small animals
Palpate pulse during induction
Observe mucous membranes
Be ready to intubate & secure airway swiftly to provide O2
Consider attaching monitoring equipment before induction
What are the key considerations for anaesthesia maintenance and monitoring in ASA III-V patients?
Continuous & comprehensive monitoring
Avoid deep planes of anaesthesia
Use PIVA or TIVA to reduce volatile agent dependence
Goal-directed IVFT
Adequate analgesia & local blocks
Keep emergency drugs calculated & ready
Minimize anaesthesia duration
Maintain body temperature (hypothermia is big risk)
What are the special considerations for anaesthetising sick horses (e.g., colic)?
IVFT before induction
Monitor PCV, TP, lactate (identify anaerobic resp), glucose, perform belly tap & NG tube
Avoid acepromazine
Use standard dose of alpha-2 agonist followed by ketamine & NSAIDs
Maintain careful positioning & ventilation (IPPV)
Provide IVFT throughout anesthesia
Use PIVA to minimize volatile agent use
Perform regular blood gas analysis
What is the benefit of providing IVFT to sicker patients before anaesthesia?
improves hypotension, reduces tachycardia & arryhthmias
Describe use of IVFT in horses prior to anaesthesia
hypertonic saline used, quickly improves circulating volume (lower volume needed than Hartmann’s) - give isotonic solution as soon as on table to replenish water reserves
