I may eventually update some of this and move to the Basics section.
Act based on intraoperative responses:
-inc BP, HR, or autonomic or somatic response
BIS Treatment
>65 inc hypnotic/analgesic, ID strong stimuli
50-65 inc analgesic, maintain hypnotic, ?NMB, ?antihypertensive med
<45 dec hypnotic, inc analgesic, antihypertensive
-stable
BIS Treatment
>65 r/o artifact, inc hypnotic
50-65 PERFECT!
<45 dec hypnotic, ?dec analgesic
-hypotension or unstable
BIS Treatment
>65 support BP, dec analgesic, consider amnestic
50-65 support BP, dec analgesic
<45 support BP, dec hypnotic, dec analgesic
Based on Glass, PSA and Johansen JW, "Technology Assessment: The Bispectral Index Monitor." Surgical Services Management, 4(10):50-52, October 1998
Approximations:
27 guage=.016" diameter
25 guage=.018"
21 guage=.032"
20 guage=.035"
3 French=.038"= 1 mm
18 guage= 4 french
16 guage= 5 french
14 guage= 6 french= 2 mm
From largest to smallest:
7 Fr
14 G
6 Fr
5 Fr
16 G
4 Fr
18 G
3 Fr
0.038"
0.035"
20 G
21G
25 G
.018"
•Tumors from enterochromaffin tissues. Usually in GI tract, usu
in appendix; occasionally in bronchi.
•Dx: inc urinary 5-hydroxyindoleacetic acid (serotonin degradation
product)
Syndrome:
•5% incidence
•results when vasoactive substances (serotonins, kallikrein, histamine)
create symptoms - overwhelm liver's ability to inactivate. Appendiceal
tumors don't produce carcinoid syndrome. By then, hepatic mets usu. present
•usually associated with hypotension, but can also cause HTN.
•triggers: Anxiety, dTC, MSO4, light anesthesia, hypotension
may stimulate release of vasoactive substances from tumor
•Anesthetic Managment
-avoid drugs that activate sympathetics, eg ketamine (catechols activate
kallikreins), or histamine releasers
-anesthetic requirements may be decreased
-consider Octreotide (50mcg iv & 50mcg SQ) 10-100mcg push prior
to tumor manipulation, then every hour. A synthetic peptide with t1/2 90-120
min, onset 15min, no rebound effect when stop giving. Problems: can inhibit
insulin release.
-If hypotension occurs, give fluids. May want to avoid alpha and sympathomimetic
drugs.
•Sns/Sxs
-Bronchoconstriction-asthma
-TR and/or PS
-PAC and SV dysrhythmias
-Episodic flushing or cyanosis
-Venous telangiectasia
-Chronic abdominal pain and diarrhea
-Hepatomegaly
-Hyperglycemia
-Decr plasma albumin
A-wave
-atrial kick
-R: peaks 80msec after p-wave
-L: peaks 240msec after p-wave
-peak=best measure of R/LVEDP
-Cannon a-waves: nodal rythms with retrograde atrial depolarization,
reentrant SVT where vent contracts before atria, heart block with atrial
activity during vent syst & tricuspid/mitral atresia
X-descent
-atrial relaxation
-X': downward displacement of TV & MV
C-wave
-isovolumic vent contraction
-follows a-wave by length of P-R interval
V-wave
-passive atrial filling while TV&MV are closed, during vent
systole
-peak determined by atrial compliance and volume of blood
-R: peaks near end of t-wave
-L: peaks after t-wave
-large v: TR or MR, large volume of blood return, poor atrial compliance.
May make PCWP trace look like PAP. Can differentiate them: PAP peaks 130msec
after ABP upstroke; V-wave 350msec
Y-descent
-rapid atrial emptying as TV/MV open
-attenuated in pericardial tamponade
-more prominent in constrictive pericarditis
•v-a merge in tachycardia
•a-c merge if short PR interval
•A Fib: no a, prominent c-wave
•Jnctl Rhythm, or V-pacing: cannon wave in early systole (d/n see usual
a-wave in end diastole).
•TR: prominent c-v (with prominent y-descent), obliterated x-descent
•TS: tall a
•RV infarct: high CVP (>=PCWP), prominent a v waves, steep x y descents
•Pericardial Constriction: PADP = PCWP = CVP. Prominent x, y (y>x)
•Tamponade: PADP = PCWP = CVP. Prominent x, attenuated y.
Size
-usually one size larger than normal OA
-measure from angle of jaw to lip (color change at lip)
Positioning
-like OA
-ensure tip is behind base of tongue
-secure strap before inflating
Size cc air
8 25
9 30
10 35
11 40
Improving Airway
-tilt head (lifts epiglottis from post. wall)
-turn, extend head (improve tissue tone in hypopharynx, reduce redundant
tissue)
-support shoulders (straightens out upper airway)
-lift chin
-CPAP (~10 cmH2O)
Removing COPA
-deflate cuff only after swallowing, coughing reflexes return
Head lift, Grip
NIF <= -25 cm H2O
RR <=30
TV >= 5cc/kg
VC >= 10 cc/kg
PaO2 > 65 on FiO2 < .40
PaCO2 < 50 torr
Resting MV < 10 l/min
Improving or stable LOC
Correction of infxn, sepsis, malnutrition, electrolyte abnormalities,
respiratory muscle weakness, CHF, PE
RR/TV < 100 breaths/min/l or TV/RR >10
Qs/Qt 20%
Vd/Vt <0.6
Static compliance >= 30 ml/cm H2O
7 things to do prior to Extubation:
Patient either deep or awake
Patient either breathing or easy to ventilate manually
Oral airway in place
Pharynx suctioned
Cuff deflated
Lungs manually inflated with 100% O2
Succinylcholine available.
NEVER extubate a patient without an oral airway in place.
AFTER you extubate a patient, suction the pharynx one more time, put
the mask on the patient, keep your right hand on the bag, test for airway
patency, and then help them breathe for a while.
Risk factors:
male
age 20-30y
hypovolemic shock
intramedullary instrumentation
rheumatoid arthritis
THA if cementing femoral stems
bilat TKA
long-bone fx (incidence 3-4%, mortality 10-20%)
Dx: 1 major and 4 minor criteria; exclude other causes of hypoxia
Major Signs:
axillary/subconjunctival petechiae
hypoxemia (PaO2<60; FiO2<0.4)
CNS depression
pulmonary edema
Minor Signs:
HR>110
hyperthermia
retinal fat emboli
urinary fat globules
dec plt/hct
inc ESR
fat globules in sputum
Onset: usually 12-40 hrs after injury
Tx:
avoid hypovolemia. albumin may be useful for resuscitation (volume,
+ binds fatty acids; may dec lung injury)
stabilize fx
respiratory support
corticosteroids may help
Classic, Disposable, or Intubating
---Max Values--
Sz Wt kg Len Cuff ETT
FOB
1 <5
10cm 3ml 3.5 2.7mm
1.5 5-10
7 4
2 10-20 11.5 10
4.5 3.5
2.5 20-30 12.5 14
5 4.0
3 30-50 19
20 6
5.0
4 50-70 19
30 6c 5.0
5 70-100 20 40
7c 5.0
6 >100 20
50 7c 5.0
ProSeal
-----Maximum Values----
Wt
Cuff --OG-- Salem Sump
Sz kg ml
mm Fr Fr
3 30-50 20
5.5 16 14
4 50-70 30
5.5 16 14
5 70-100 40 6.0
18 16
-is the anesthetic concentration that prevents responsiveness to
commands (squeeze my hand) in 50% of patients
-slightly overestimates MACaware (recall)
-clinically, ED95 would be more useful. To prevent recall, should probably
maintain 0.6-0.8 MAC (modern) volatile agent.
As percent of MAC:
-propofol 18% (Cp50; percent of plasma concentration)
-isoflurane 38%
-sevoflurane 33% ?
-desflurane 36%
-N2O 64%
-halothane 52%
-methoxyflurane 52%
-ether 60%
Sources for percentages:
iso, N2O: Dwyer et al, Anesth 77: 888-98, 1992
halo, methoxy, ether: Stoelting et al, Anesth 33: 5-9, 1970
des, propofol: Chortkoff et al, Anesth Analg 81: 737-43, 1995
sevo: not sure where I got it!