Foundations - Exam 2

What do we monitor with anesthesia?

Anesthetic depth, CVS, respiratory, temperature

Subjective monitory - Anesthetic Depth

Jaw tone, eye position, palpebral/corneal reflexes, rectal tone

Anesthetic Depth - objective monitoring

HR, RR, BP, EEG/BIS

Eye position and eye reflexes should be where when in the surgicla plane

Eyes - ventromedial
Eye reflexes - loss of palpebral reflex

5 main cuases for delayed recovery

Anesthesia still on, Hypothermia, Hypotension, hypoglycemia, hypercapnia

Cardiovascular - subjective monitoring

Mucous membrane color, capillary refill time, cardiac auscultation, pulse palpation

Cardiovascular system - objective monitoring

ECG, BP

Muscous membranes are an assessment of ___ while capillary refill time is an assessment of

oxygenation and perfusion
Assessment of perfusion

ECG is a visual representation of

the electrical activity of the heart not if it contracts

ECG in LA

White - neck
Black - apex of heart
Red - neck

Arrhthmias when under anesthesia occur as a consequence of

Various disorders or drugs administered

Blood pressure is representative of

perfusion pressure to the periphery
marker of tissue perfusion

MAP should be at

SA: 60-150 mmHg
LA: >70mmHG

How to measure BP

Invasive - arterial catheter connected to a pressure transducer
Oscillometric - cuff
Doppler + Sphygomonometer - when sound returns - Systolic arterial pressure

When to use invaise BP

Critical P in which fluctuations in BP are anticipated

Cat BP readings is weird becuase

In doppler that cats pressure when sound returns is closer to mean

Non-invasive BP is less accurate when

severe hypotension, severe hypertension, arrhthmias

MAP =

CO x systemic vascular resistance

Brady cardia management

Anticholinergic - atropine or glycopyrrolate
Sympathomimetic - ephedrine

Tachycardia management

Beta blocker - esmolol

Ways to assess preload

PE/PCV/TS
Thoracic x-rays
pleth variability index
Echo or central venous pressures

Decreased preload management

1) Isotonic crystalloid fluid bolus
Hypertonic crystalloids, colloids, blood products

Fluid boluses should be avoided in P with

Cardiovascular disease

What are 3 reasons for lameness

pain, mechanical restriciton, neurologic deficits

What does a lameness exam consit of

Musculoskeletal palpation and stand back and look at the horse
Dynamic exam - Flexions, blocking
Imaging

What are you evalating on the musculoskeletal palpation of an equine lameness exam

Areas of sensitivity and heat, obvious soft tissue swelling, joint effusion
Assymmetry in pain, effusion, swelling/thickkening

Hoof tester test for hoof sensation and pain in the

wall, sole, frog, heel bulbs

Canter/Lope

Rocking type motion through hindend then forehand
If turing, inside HL and inside FL should land first

Gaiting

Four beat gaits with the same pattern as walk
A really fast walk

Steps to a dynamic exam

1) Is horse lame or sound
2) If lame, is horse lame in forelimb, hindend or both
3) Which limbs are lame
4) Grade the lameness in each limb

Forelimb lameness - what happens to cause the signs we see

Pain → decreased load → Decreased flexion → decreased decent of trunk

How to tell whcih leg is lame in equine lamenss

Forelimb - down on sound
Hindlimb - increased gluteal excursion (hip drop or hip hike)

Lamness exam at a lunge line - signs of lameness

Can exacerbate the lameness, shortened cranial phase of the stride, axial placement of the hind limb, slow to advance the hindlimb, reduced stance duration

Signs of lamness at the canter

Lack of dissociation of the hindlimbs, lack of flexion through lumbosacral region, incorrect lead

Sings of lameness - Attitude

Reluctance to go forward, head shaking/tail swishing

Grading lameness: Equine AAEP scale

5- non weightbearing lame
4- Lame at the walk
3- consistiently lame at the trot under all circumstances
2 - consisitently lame at the trot under certain circumstances
1 - inconsistently lame at the trot under certain circumstances

Equine Bilateral leameness can be hard to detect so look for

Short, choppy, or shuffling gait

Flexion Tests - Distal limb

Stresses fetlock, pastern, coffin joints

Flexion Test - proximal hind limb

Stresses stiffle, lumbar back, SI

Flexion Test - Full limb hind

Stresses all joints in the hindlimb except hock/proximal metatarsus region not stressed with other hindlimb flexions

Ridden exam for lameness Exam

performed for subtle lameness or ones that occurs only during a certain movement, lameness that the rider can feel

Diagnositc Analgesia Contraindications

Local inflammation, cellulitis, dermatitis
Suspcion of a fracture - recent severe lameness, incomplete fracture
Laminits - ok for diagnosis but not repeated injections

Peri-neural nerve blocks start where and move where and how to give

Start nerve blocks distally and move proximally
(nerves are continuos)
Aim needle distally when possible
low volume as possible
Look at horse soon after performing block

What drug do you use for blocking equine and it’s method of action

Carbocaine
Blocks Na channels and prevents depolarization of membranes (blocks nerve conduction)