Hi Matt,
I'm guessing you don't intend for those codes to be separated by ampersand. In FHIR, this means "AND" whereas comma separation means "OR" [1]. In order to get a list of items matching any of the loincs below, you would have one code parameter with a bunch of comma-separated values. EG:
Observation?subject%3APatient=4342010&code=http%3A%2F%2Floinc.org%7C3141-9,http%3A%2F%2Floinc.org%7C8302-2,http%3A%2F%2Floinc.org%7C2093-3,http%3A%2F%2Floinc.org%7C2571-8,http%3A%2F%2Floinc.org%7C2085-9,http%3A%2F%2Floinc.org%7C13457-7,http%3A%2F%2Floinc.org%7C55284-4,http%3A%2F%2Floinc.org%7C72166-2
Also, you'll need to query by this code for now for tobacco usage answers:
http://snomed.info/sct|229819007 (we have an enhancement coming in just to get the usage answer, but it's not there yet)