If an employer drives an injured employee to the hospital after getting injured at work and their condition worsens along the way, is the employer liable?

As long as the employer did not do anything to bring on the worsening of the employees condition - did not take the longer route or something affirmative - then I can not see any situation in which the employer would be held liable under the facts as you have presented here.  It seems to me that the employer could fall under what has been called the Good Samaritan law by administering help to some one who needed it even if arguably one could say he had a duty to drive him in the first place.  This is obviously weighing on your mind.  Please go and seek consultation from an attorney in your area who can give you guidance based upon all the facts.  Good luck.

Pretty much all states in this country have what is called "the good samaritan rule".

Under this rule, if a person assists one who is injured in a situation which essentially requires emergency care immediately or within a reasonable time and the person assisting the injured person aggravates the injuries that the person has, the "good samaritan" would not be liable for the injuries that worsened for the injured person.

This rule results from public policy considerations that it is inherently unfair to penalize someone who undertakes assistance to an injured person when that person has no obligation to do so.

If an employer drives an injured employee to the hospital after injury out of necessity for medical treatment and the condition of the injured person worsens along the way, the employer would not be liable for worsening the injured employee's condition.