10 / 12
1 4
INTERNSHIP SURVIVAL GUIDE
•
To correct for isopropyl alcohol + ([IPA]/6). And in this case, IPA
does not stand for India pale ale.
•
To correct for ethylene glycol + ([EG]/6.2).
•
To correct for mannitol + ([mannitol]/18.2).
OSMOLAL GAP
Osmolal gap = measured S
osm
−
calculated S
osm
•
Causes of increased osmolal gap: decreased serum water, hyper-
proteinemia, hypertriglyceridemia, and presence of unmeasured
osmoles (e.g., sorbitol, glycerol, mannitol, ethanol, isopropyl alco-
hol, acetone, ethyl ether, methanol, and ethylene glycol)
•
Every time you drink alcohol you have an osmole gap! Unless you
correct for it as mentioned.
RETICULOCYTE INDEX
Reticulocyte index = [reticulocyte count × (Hct/45)]/maturation factor
Maturation factor = 1 + (0.5 × [(45
−
Hct)/10])
•
Good marrow response = 3.0-6.0. You go marrow!
•
Borderline response = 2.0-3.0
•
Inadequate response = <2.0. Gosh marrow, is that the best you
can do?
MELD Score
Observed Mortality (over 3 mo) (%)
>40
71.3
30-39
52.6
20-29
19.6
10-19
6.0
<9
1.9
Adapted from Wiesner R, et al. Model for end stage liver disease (MELD)
and allocation of donor livers.
Gastroenterology
2003;124:91-6, with
permission.
TABLE 4-1
MORTALITY BASED ON MODEL FOR
END-STAGE LIVER DISEASE (MELD)
SCORE