Nitrous/Sevoflurane Flashcards
What is the MAC value of Nitrous?
104%
What is the metabolism rate of Nitrous?
0.004%
In a Nitrous tank when the pressure begins to decrease, about how much is remaining in the cylinder?
~400 L
What is the BGPC of Nitrous?
0.46
What property does Nitrous have that no other VA shares with it?
prominent analgesic effects—>10% nitrous = 7.5 mg morphine
Can Nitrous cause skeletal muscle relaxation?
No actually can cause rigidity
What is the mechanism of action related to the analgesic effects of Nitrous?
N2O produces analgesia via opioid like neurons in the periaqueductal gray matter of the brain stem. These neurons project to the dorsal horn of the spinal cord where they act through alpa-2B adrenergic receptors inhibiting nociception
Nitrous provides analgesia by inhibition of the dorsal horn nociceptive neurons
Nitrous may increase motor activity with ___ and ___.
clonus and opisthotonus
Substitution of nitrous for a portion of VA ___ the magnitude of BP decrease produced by the same MAC {} of the VA alone.
decreases
Is PHT contraindicated for N2O administration?
yes due to increased CVP secondary to increased PVR
Which type of shunt patient should not receive N2O?
those with Right to Left shunts
Nitrous do’s:
hastens inhalation induction-second gas effect lower VA MACS deeper levels of anesthesia Hasten emergence with Iso/Sevo Analgesia
Nitrous don’ts:
laparoscopic cases bowel cases cases with potential for air emboli PONV patients Vitamin B12/folate metabolism deficiencies Pneumothorax abuse Muscle relaxation potential for hypoxia free flaps hasten Desflurane emergence PHT R to L shunts
What is the BGPC of Sevoflurane?
0.69
What agent is in Sevo making it nonflammable?
Fluorines—>they replace the hydrogens
What is the MAC value of Sevo?
2.1%(or 1.8% in some text)
What is the MAC BAR of Sevo(blocked autonomic reflex)?
1.5 x MAC
On how much MAC Sevo can you intubate?
2 x MAC
Hyperthermia reduce or increase the amount of VA needed?
reduce
Patients with lower cardiac outputs will take longer or be faster to put to sleep?
Lower CO faster to sleep
What percentage of the body mass is the VRG?
10%
What percent of the body’s CO goes to the VRG?
75%
At what percentage does the cerebral metabolic oxygen requirements begin to decrease on Sevo?
0.4 MAC
At what level does EEG activity cease while on sevo?
2 MAC
At what MAC does Sevo cause EEG burst suppression?
1.5 MAC
At what MAC does Sevo cause increased blood flow to the brain—>increased ICP?
0.6 MAC
Sevo circulatory effect will disappear in about ___ hours?
5 hrs
Sevo neuro alterations will disappear in about ___ hours
4 hrs
In contrast to Iso and Des, neurocirculatory responses do not accompay…..?
abrupt increases in Sevo concentrations. Sevo is smoother
Can Sevo cause Halothane hepatitis?
Sevo cannot form trifluoracetylated protein antibodies resulting in immune mediated hepatotoxicity. The chemical structure of sevo does not allow metabolism to an acetyl halide
Should Sevo be avoided in patients with ESRD?
yes
What % Sevo is metabolized?
5%
Compound A can be caused from ?
HGF LGF closed circuits Metabolism rates Higher temps
mostly LGF and minimal flow anesthesia
Is Sevo a triggering agent for MH?
yes
