Im actually surprised by the number of people having trouble answering this question.
Respiratory Distress: Is a symptom they are experiencing. The patient is short of breath. (dypsneic). It also involves the psychological aspect of dyspnea.
Respiratory Failure: Inadequate gas exchange at the alveolar level. There are two types.
Hypoxic (Type 1) which means on a blood gas or pulse oximeter the SaO2/PaO2 or SpO2 if Pulse Ox are decreased.
Hypercapneic (Type 2) means the patient is unable to adequately eliminate CO2. On a blood gas the patient would have an elevated PaCO2 or with Capnography and elevated EtCO2.
Treatment for respiratory failure should always involve increasing the airway pressure either by intubation with mechanical ventilation or non-invasively with either CPAP for hypoxic failure or CPAP with PS (BiPAP) for Hypercapneic failure. If the patient has a significant shunt (meaning obstruction of lower airways not allowing oxygen to get to the functional levels of the lung) then increasing the FiO2 or percentage of O2 will not help.
CPAP is often times adequate for hypoxic failure as one provides extra pressure expanding the alveoli thus increasing surface area and oxygenation. CPAP will not substantially help hypercapneic failure as it does not increase tidal volumes.
BiPAP or CPAP with Pressure Support will likely be beneficial for Hypercapneic failure because the pressure is ramped up when the patient takes a breath improving tidal volumes thus allowing the patient to blow off more CO2.
Last edit by kdavis308 on Sep 15, '12