Transcript Moyamoya disease

O2 vs N2O.
Who’s the bad guy??
YEE L. KWAN, RN, CCRN
DUNAP, CLASS OF 2013
OCTOBER 22, 2012
How many of you…
Always use 100% O2 for
emergence?
50%
50%
1. Yes
2. No
1
2
I routinely…
50%
50%
Titrate the FIO2 to the
lowest amount my patient
needs to maintain their
baseline sat.
1. Yes
2. No
1
2
What’s the point?
By the end of this presentation you should be
able to…….
1.Discuss the pros & cons of O2 and N2O use
2.Identify risks for and s/s of O2 toxicity
3.Discuss various methods/techniques to
prevent atelectasis in our pts
O2 IS GOOD B/C
• Well, it’s essential to life!
• Possible prevention of surgical site
infection (SSI)
• Can reduce incidence of PONV
• Prevention of hypoxia
Meyhoff, C.S., Staehr, A. K., & Rasmussen L. S. (2012)
HAZARDS OF O2 THERAPY
• Oxygen toxicity
• Absorption atelectasis*
• Induced hypoventilation
• Fire hazard
• Retinopathy of Prematurity (ROP)
Atelectasis….did you know?
• In 90% of anesthetized pts
• Both with spontaneous ventilation
and paralysis
• Edmark et al. – CT of lungs of
anesthetized patients
• PEEP – 10 cmH2O
• VC maneuver – 40 cmH2O, 7-8s
• Benoit et al. – postop atelectasis
Atelectasis….did you know?
Benoit et al. (2002)
I typically….
Use N2O regularly as part of my
anesthetic (assuming no
contraindications).
33%
33%
33%
1. Yes
2. No
3. Depends on who I’m
working with that day
1
2
3
I don’t use N2O because…..
1. I’m not comfortable
with it
2. I prefer to keep
things simple
3. Risk of N&V
4. My preceptors don’t
like it
25%
1
25%
25%
2
3
25%
4
N20 IS GOOD B/C
• Has analgesic effects
• Rapid uptake and elimination
• Little cardiac or respiratory depression
• Nonpungent
• Additive effect with co-administration of
other volatile agents
• Can speed up the rate of lung collapse
for OLV
2nd gas effect…in reverse
• Using the 2nd gas effect to
speed up emergence
• Peyton et al. found
• Time to eye opening and
extubation were significantly
shorter
• Partial pressure of Sevo 39%
higher
N20 CONTRAINDICATIONS
ABSOLUTE
Known deficiency of
enzyme or substrate
in methionine
synthase pathway
Gas filled spaces
Increased ICP
RELATIVE
Pulmonary HTN
Prolonged
anesthesia >6hrs
1st trimester
High risk PONV
Risk of MI
Do you use recruitment maneuvers
during your anesthetics?
1. Yes
2. Not usually
3. No
33%
1
33%
2
33%
3
When I use a recruitment
maneuver I apply pressure to
25%
1.
2.
3.
4.
25%
25%
2
3
25%
20cmH2O
30cmH2O
40cmH2O
I don’t
know. I just
squeeze
until it feels
“about
right”
1
4
After this presentation I will
definitely think about using N2O on
my next patient
50%
50%
1. Yes
2. No
1
2
In summary…..
•
Lots of evidence already exists both pro
and con
•
Every patient requires individual
consideration
•
There never is a right or wrong choice
•
Think about why you do what you do –
is there a good rationale?
References:
Edmark, L., Kostova-Aherdan, K., Enlund, M., & Hedenstierna, G. (2003). Optimal oxygen concentration during
induction of general anesthesia. [Clinical Trial Randomized Controlled Trial]. Anesthesiology, 98(1), 28-33.
Edmark, L., Auner, U., Enlund, M., Ostberg, E., & Hedenstierna, G. (2011). Oxygen concentration and characteristics
of progressive atelectasis formation during anaesthesia. [Research Support, Non-U.S. Gov't]. Acta anaesthesiologica
Scandinavica, 55(1), 75-81. doi: 10.1111/j.1399-6576.2010.02334.x
Grocott, H. P. (2008). Oxygen toxicity during one-lung ventilation: is it time to re-evaluate our practice? [Review].
Anesthesiology clinics, 26(2), 273-280, v. doi: 10.1016/j.anclin.2008.01.008
Hedenstierna, G., & Edmark, L. (2010). Mechanisms of atelectasis in the perioperative period. [Research Support,
Non-U.S. Gov't Review]. Best practice & research. Clinical anaesthesiology, 24(2), 157-169.
Hedenstierna, G., & Rothen, H. U. (2000). Atelectasis formation during anesthesia: causes and measures to prevent
it. [Review]. Journal of clinical monitoring and computing, 16(5-6), 329-335.
Meyhoff, C. S., Jorgensen, L. N., Wetterslev, J., Christensen, K. B., & Rasmussen, L. S. (2012). Increased Long-Term
Mortality After a High Perioperative Inspiratory Oxygen Fraction During Abdominal Surgery: Follow-Up of a
Randomized Clinical Trial. Anesthesia and analgesia. doi: 10.1213/ANE.0b013e3182652a51
Rothen, H. U., Sporre, B., Engberg, G., Wegenius, G., Hogman, M., & Hedenstierna, G. (1995). Influence of gas
composition on recurrence of atelectasis after a reexpansion maneuver during general anesthesia. [Clinical Trial
Comparative Study Randomized Controlled Trial Research Support, Non-U.S. Gov't]. Anesthesiology, 82(4), 832-842.
Staehr, A. K., Meyhoff, C. S., & Rasmussen, L. S. (2011). Inspiratory oxygen fraction and postoperative
complications in obese patients: a subgroup analysis of the PROXI trial. [Comparative Study Multicenter Study
Randomized Controlled Trial Research Support, Non-U.S. Gov't]. Anesthesiology, 114(6), 1313-1319. doi:
10.1097/ALN.0b013e31821bdb82
Vimlati, L., Kawati, R., Hedenstierna, G., Larsson, A., & Lichtwarck-Aschoff, M. (2011). Spontaneous breathing
improves shunt fraction and oxygenation in comparison with controlled ventilation at a similar amount of lung
collapse. [Comparative Study Research Support, Non-U.S. Gov't]. Anesthesia and analgesia, 113(5), 1089-1095. doi:
10.1213/ANE.0b013e31822ceef8