I don't know who wrote this question, but it is blatently apparent that you have no comprehension of what a CRNA is/does. As a critical care nurse who is both nationally certified in Critical Care and sub specialized in Cardiovascular Surgical Critical Care, as well as a current CRNA student, I am well aware of the qualifications and rigors that are required of a CRNA.
1.) First and Foremost the CRNA is the Ultimate Airway manager. CRNAs (as well as MDAs) are the experts in Emergency management and ventilation, as well as emergency access to patent airways
2.) The CRNA is essentially a hemodynamic badass, or at least that is the intent. This is why CRNA schools require the CCRN certification for school. In critical care, especially cardiovascular critical care you learn in depth hemodynamic control. As a CVSU nurse I have been left alone on thousands of occasions to manage fresh post op hearts. I manage all aspects of swan gang cath care such as SVR, CVP, PA pressures. I have to know normal pressures, how to manage pressures, and patient trends. I have to not onl know what drips do, but how they work. I have to know that dobutamine is a positive ionotrope and that it acts on beta 1 and 2 as well as alpha 1 and 2 andrenergic receptors. I have to know that because it acts on all of these receptor sites there is a potential for many side effects. Such as, bc it is a beta 1 agonist it will increase ionotropy, lusitropy, chronotropy, and dromotropy. If my patient is dry and their CI is low I have to know that dobutrex's influence on chronotropy will probably throw my patient into Sinus tach, and that I should probably give fluid instead of starting dobutrex. The fluid will increase CVP and preload, which is greatly needed in a post op heart that has severe myocardial stunning from beta blockers and cardiapleagia, not to mention the cool 92 degrees that the heart may be. I have to know that giving fluids and rewarming the patient will allow the patient to loosen their Systemic Vascular Resistance and therefore decrease after load and increase CI/COO. I have to know that the formula for SVR is (MAP-CVP*80)/COCO and that if I have an inadequate CVP waveform I will not have an accurate SVR.
3.) Beyond number two, the CRNA is well versed in all areas of Critical Care IE Central line placement, airway management, epidural/pain control, Arterial line placement/management, hemodynamic stabilization, airway management.
In fact there is a really good article written by an MD in a book called Clinical Anesthesiology by Morgan and Mikhail (you MDA buffs should have this one), in which the Dr. talks about CRNAs being in a prime position to be acute care physicians within the current medical arena.
I hope this clears up what Critical Care has to do with being a CRNA. When you have a patient on the OR table who has had their entire Autonomic nervous system wiped out by anesthetics, beta blockers, and various other drugs you better be a bad ass at managing hemodynamics, and there is no better place to learn this than in critical Care.