There are two types of general impairment in a Pennsylvania and Bucks County DUI. They fall under 75 Pa.C.S.A. 3802, specifically 3802(a)(1) or 3802(a)(2).
§ 3802. Driving under influence of alcohol or controlled substance.
(a) General impairment --
(1) An individual may not drive, operate or be in actual physical control of the movement of a vehicle after imbibing a sufficient amount of alcohol such that the individual is rendered incapable of safely driving, operating or being in actual physical control of the movement of the vehicle.
(2) An individual may not drive, operate or be in actual physical control of the movement of a vehicle after imbibing a sufficient amount of alcohol such that the alcohol concentration in the individual's blood or breath is at least 0.08% but less than 0.10% within two hours after the individual has driven, operated or been in actual physical control of the movement of the vehicle.
Here's an example -- say you have a person who hired a Quakertown DUI lawyer to represent her in a DUI. The lawyer sees that the blood test results come back with a BAC of .102. There is an argument to be made by the attorney that the BAC is within the margin of error and should be rounded down below .10, putting the individual in the 3802(a)(2). That would reduce potential jail and a license suspension.
Say the blood/lab results are corrupted and/or suppressed. You can still be convicted of a DUI based upon an officer's testimony that their professional experience lead them to the conclusion that you were incapable of safely driving based upon alcohol or drug use. It's a bit more complicated than just that, so you probably want to talk to a Bucks County criminal attorney to clear things up.