What is the standard of care for a plaintiff in a medical malpractice case?

'In the usual negligence case the standard of care against which the jury measures the conduct of the defendant is that of the ordinary, reasonable, prudent man. The jury, from its own lay 'expertise,' at once establishes the standard and judges its breach. But there are exceptions to this rule of which the instant case is one. * * * Thus, in this area the jury, unaided by proper expert testimony, will not be permitted to make a finding of negligence. * * * Thus, it is incumbent upon the plaintiff in this class of cases to establish the standard of care, not of the ordinary prudent man, but of the prudent, skilled, trained physician. [Citations.] Because of the wide area which must be allowed for differences of 'judgment' in a learned profession, testimony of other physicians that they would have done something different, standing alone, is insufficient to sustain a verdict for the plaintiff. Richison v. Nunn, 57 Wash.2d 1, 2, 16, 340 P.2d 793, 801 (1959). Rather, the local community standard of practice must be shown, and this applies fully to cases of alleged faulty diagnosis. * * *.' (Emphasis in original.)