Lecture 11 9/18/24 Flashcards
What is the importance of anesthetic depth?
-too light of depth can result in patients experiencing pain and other sensation
-too deep of depth can result in physiologic derangement
What are the determinants of anesthetic depth?
-amount of drug in the CNS
-magnitude of procedural stimulation
-underlying conditions
Why does the type of anesthetic drug matter?
some drugs are good at depressing the CNS while others are good at analgesia
Where should a patient fall on the anesthesia depth chart during a procedure?
plane 2 or 3 of stage 3
What are the characteristics of muscle tone?
-decreases as depth increases
-jaw tone most commonly used in small animal
-neonates and pediatrics will have naturally decreased muscle tone due to anatomy
-neck muscles and palpebral reflex are assessed in horses
-muscles should be relaxed under GA; persistence indicates light plane
-assess muscle tone in reference to other signs of depth
What is the ideal eye position during GA?
-small animal and ruminants: ventromedial
-horses: central w/ no or slow movement
What are the ideal ocular reflexes during GA?
-no/slow palpebral reflex
-no dazzle reflex
-dilated pupils
-no lacrimation
What are important things to note regarding anesthetic depth?
-“typical” drug doses do not correlate with a particular plane; each patient varies
-no correlation between level of anesthesia and physiologic consequence
What are the important characteristics of patient position?
-want to try and achieve proper position the first time
-avoid pressure points
-consider co-morbidities such as arthritis
What are the characteristics of blood glucose?
-important substrate for cellular function
-patients that have difficulty with glucose homeostasis will need this accounted for in their monitoring plan
What are the characteristics of urine output?
-renal function is altered by anesthetic drugs
-want to monitor ins and outs and assess if positive fluid balance is normal for patient metabolism or not
-inappropriate positive fluid balance is associated with increased morbidity and mortality
Why does hemorrhage cause double damage to delivery of oxygen?
it results in volume loss/low CO as well as decreased oxygen carrying capacity/CaO2
What are the steps to estimating blood loss?
-calculate patient’s blood volume
-calculate % of blood that patient can tolerate losing
-estimate blood lost and compare to the tolerance value
What are the characteristics of recovery?
-majority of anesthetic deaths occur in recovery due to ceased monitoring
-monitoring plan for recovery should be similar to procedure
-ensure maintenance of homeostasis before leaving patient alone
-prepare for complications and know how to address them
What are the most important aspects of monitoring?
-monitor the patient first; more accurate than monitors
-monitor the equipment, surgeons, and any miscellaneous components
-tailor the monitoring plan to the patient
-keep thorough and accurate records
