Query: What was the result of my last sodium level test?, FHIR Resource: {'resourceType': 'Observation', 'status': 'final', 'category': [{'coding': [{'system': 'http://terminology.hl7.org/CodeSystem/observation-category', 'code': 'laboratory', 'display': 'Laboratory'}]}], 'code': {'coding': [{'system': 'http://loinc.org', 'code': '2951-2', 'display': 'Sodium [Moles/volume] in Serum or Plasma'}], 'text': 'Sodium [Moles/volume] in Serum or Plasma'}, 'subject': {'reference': 'urn:uuid:dd5066ef-674c-3f45-1f3a-4e65602d398f'}, 'effectiveDateTime': '2005-01-12T16:56:17+05:30', 'valueQuantity': {'value': 141.37, 'unit': 'mmol/L', 'system': 'http://unitsofmeasure.org', 'code': 'mmol/L'}, 'interpretation': None}