Medical malpractice is just ordinary negligence by a healthcare provider which causes injury.
It is no different in theory than negligence by a motorist who does not pay attention and runs a red light causing an injury. Florida has a statute which defines the standard of care as that level of care, skill and treatment which is recognized as acceptable and appropriate by reasonably prudent similar healthcare providers under similar circumstances. In a malpractice trial, the judge tells the jury about this definition, and after hearing the evidence of what happened the jury decides what they believe a reasonably prudent similar healthcare provider should have done under the circumstances. This decision by the jury is normally aided by the testimony of expert witnesses from both sides, who explain the medical issues during the trial. That harder to prove standard of care for emergency room cases has been added as a section to Florida's Good Samaritan Statute, which is Section 768.13 Florida Statutes .