"the ICU book" by marino is the standard to use. it's not pocket size, more like a reference book but it gives a good overview on all settings, swan measurements, major cardiac drugs, general icu care...etc. it's from 1998 so obiviously the drug data is old but you can get that from other sources. vents and swans haven't changed too much in the past 10 yrs so get the old (2nd ed) for $10 at amazon instead of the (3rd ed) for 60!
I think tarascon makes a pocket ICU book...anyone know if it's any good?