Lecture 3

Question 1

What is important to assess in birds prior to anesthesia?

Answer 1

-body condition
-cardiopulmonary status
-overall physiological stability

Question 2

What are the characteristics of dehydration correction in birds?

Answer 2

-fluids can be given IO, SQ, or IV
-absorb fluids really well
-be aware of continued losses; bleeding, vomiting, diarrhea
-75 ml/kg/day maintenance rate

Question 3

How is anemia corrected in birds?

Answer 3

-fluids
-blood transfusion

Question 4

How is hypoglycemia corrected in birds?

Answer 4

dextrose

Question 4

What are the characteristics of ASA status?

Answer 4

-assessment of patient’s pre-anesthesia medical comorbidities
-clinical decision with multiple affecting factors
-can change with changes in patient status

Question 5

What are the ASA classes?

Answer 5

1: normal, healthy patient
2: mild systemic dz
3: severe systemic dz
4: severe systemic dz; constant threat to life
5: moribund; not expected to survive w/o procedure

Question 6

What are the characteristics of fasting birds for anesthesia?

Answer 6

-small birds (less than 200g) fast for ~ 3 hrs
-larger birds fast for ~ 6 hrs
-ideally want an empty crop and reduced proventricular distension

Question 7

How can surgery in birds best be prepared for?

Answer 7

-know emergency drug doses; esp. atropine and epinephrine
-prepare checklist, supplies, personnel, and procedure plan

Question 8

What are the characteristics of anesthetic death in birds?

Answer 8

-higher death rate than dogs and cats within 48 hours of anesthesia
-majority of patients that die do so within 3 hrs of procedure end time

Question 9

What are the most important factors to prevent anesthetic death in birds?

Answer 9

-reduce anesthesia time
-adequate monitoring during and post-anesthesia
-be aware of increased risks in sicker animals

Question 10

What are the typical anesthesia protocols in birds?

Answer 10

-start with 100% O2 and slowly increase isoflurane PRN
-start at 3% isoflurane and inc. or dec. PRN
-start at 5% isoflurane and dec. PRN

Question 11

Why is avian anesthesia typically done with gas (isoflurane) alone?

Answer 11

highly efficient resp. tract allows for rapid induction and recovery with gaseous anesthesia

Question 12

What are the characteristics of gaseous anesthesia in bald eagles?

Answer 12

-reports of arrhythmia with isoflurane
-arrhythmia possible with sevo. but less so
-sevo. recommended over iso. in bald eagles; especially if compromised

Question 13

What are the characteristics of sedation protocols in birds?

Answer 13

-typically use intranasal or IM midazolam
-midazolam can be reversed with flumazenil
-ketamine is possible; no reversal (not commonly used)

Question 14

What are the characteristics of bird intubation?

Answer 14

-be aware of complete tracheal rings
-use non-cuffed, silicone tubes
-minimize head and neck movement to prevent tracheal strictures

Question 15

What are the characteristics of pulse ox. monitoring in birds?

Answer 15

-based on mammalian O2-Hb dissociation curve
-not validated for birds
-evaluate for trends rather than just the number alone

Question 16

What are the characteristics of respiration monitoring in birds?

Answer 16

-want 10 to 30 breaths per minute
-assess in line with depth of respirations and SpO2
-be prepared to assist with ventilation

Question 17

What are the locations for doppler monitoring in birds?

Answer 17

-superficial ulnar/deep radial artery just inside elbow
-roof of oropharynx in larger birds

Question 18

What are the characteristics of ECG monitoring in birds?

Answer 18

-blunt alligator teeth to avoid skin damage
-values vary by species; trends are more important
-Ta wave is present in some species; represent atrial repolarization
-S wave is dominant in birds (largest)

Question 19

What are the characteristics of temp. monitoring in birds?

Answer 19

-hypothermia is a major concern
-use heat pads, bair hugger, warm fluids, and warm environment to maintain temp.
-reduce anesthesia time to lower hypothermia risks

Question 20

What are the characteristics of blood pressure monitoring in birds?

Answer 20

-typically indirect measurement
-pediatric cuffs
-placed on distal humerus over brachial artery or tibiotarsal-tarsometatarsal joint over dorsal metatarsal artery

Question 21

What is important regarding surgery in birds?

Answer 21

-need to have a clear surgical plan and a plan B
-be aware of limitations/difficult procedures
-reach out to specialists as needed
-make owners aware of all potential risks

Question 22

How are birds prepared for surgery?

Answer 22

-pluck feathers
-clean skin with chlorhexidine
-avoid betadine; causes skin reactions
-beware of too much alcohol; contributes to hypothermia

Question 23

What are the characteristics of ventral midline approach in birds?

Answer 23

-bird is in dorsal recumbency
-simple single incision provides limited exposure
-can create Y-shaped incision by extending along sternum
-difficulties with gas anesthesia since multiple air sacs must be opened

Question 24

What does a ventral midline approach provide access to?

Answer 24

-mid-abdominal masses -uterine masses -generalized abdominal dz

Question 25

What are the characteristics of transverse abdominal approach in birds?

Answer 25

-bird is in dorsal recumbency -incision made midway between vent and caudal sternum

Question 26

What does a transverse abdominal approach provide access to?

Answer 26

viscera similar to ventral midline but with overall more exposure

Question 27

What are the characteristics of a left lateral approach in birds?

Answer 27

-left leg is pulled caudally -skin incision made from middle of pubis to sixth rib -must be careful around femoral artery

Question 28

What does a left lateral approach provide access to?

Answer 28

-repro. tract -ventriculus -proventriculus -spleen -left kidney -some intestines

Question 29

What are the characteristics of crop surgery?

Answer 29

-crop is very superficial and liable to trauma and burns -crop biopsy is relatively simple and used to diagnose proventricular dilation disease -stay sutures are useful; very thin tissue -close with continuous or inverting pattern

Question 30

What are the characteristics of orthopedic procedures in birds?

Answer 30

-avian bones heal very well if fractures are closed -can use bandages, IM pins + external fixator, or plates depending on fracture type

Question 31

What are the scientific names for surgical procedures in birds?

Answer 31

-coeliotomy: surgery within body cavity (coelom) -ingluviotomy: surgery within the crop

Question 32

What are the characteristics of analgesia in birds?

Answer 32

-preemptive analgesia can reduce or prevent prolonged CNS changes due to pain -local anesthetics commonly used are bupivicane and EMLA cream (lidocaine + prilocaine)

Question 33

What are the characteristics of opioids in birds?

Answer 33

-lack of information regarding effectiveness -poor knowledge of mu and kappa receptor distribution -morphine (mu agonist) works well; species dependent -butorphanol (kappa agonist) provides most consistent analgesia based on studies -buprenorphine (partial mu) has mixed results in avian species

Question 34

Which NSAIDs are most commonly used in birds?

Answer 34

-meloxicam -celecoxib

Question 35

What are important aspects of avian anesthesia recovery?

Answer 35

-ensure cessation of gas/flush system -keep animal warm -clinical decision on keeping vs removing catheter -keep intubated until regain head control -place into warmed area with rolled up towel as nest -prop animal up -monitor closely