A selection of resources
The NICE guidelines aren't particularly specific or helpful but they do have a 2 page summary of antibiotic therapy in COPD exacerbation.
Two suggested scoring systems are DECAF and BAP-65.
British thoracic society has a detailed guide to NIV.
Some of the finest free to access resources out there
This systematic review suggests that benefit is largely limited to those with severe exacerbations.
This systematic review indicates fairly definitively that although steroids very effective, the side effect frequency is high (NNH 4-10).
EMJ review has a simple review of NIV and the evidence and thorax review is more detailed.