The plaintiff, Richard R. Miller, appeals from the trial court’s refusal to grant a motion for a new trial or judgment n.o.v. following a verdict for the defendant, in a medical malpractice case. The issues concern instructions on res ipsa loquitur, the,physician as a guarantor of results, the liability of a physician for a mistake in *274judgment and “informed consent.” Also presented and discussed are issues regarding the rejection of certain proposed exhibits and the trial court’s removal of the claim of faulty post-biopsy care from the jury.
Dr. Kennedy is a board certified specialist in internal medicine, with subspecialties in heart and nephrology, practicing in Tacoma, Washington. The plaintiff first consulted with Dr. Kennedy on January 14, 1970, complaining of fatigue, lightheadedness, tiring out easily and becoming shortwinded with exercise. Dr. Kennedy examined Mr. Miller, wrote down his medical history and took an electrocardiogram. At that time, Dr. Kennedy found that Mr.. Miller had first-degree heart block. On January 20, 1970, Mr. Miller returned for further examination and was found to have second- and third-degree heart block. Mr. Miller was immediately hospitalized and placed in intensive care. On January 26, 1970, Mr. Miller was removed from intensive care and placed in a ward.
Many tests were performed to assist Dr. Kennedy in his efforts to diagnose the cause of Mr. Miller’s heart disease. Various tests showed evidence of a kidney problem, and therefore Dr. Kennedy felt that a kidney biopsy was necessary. Witnesses for both parties testified that the decision to perform the biopsy was not malpractice. However, Mr. Miller testified that Dr. Kennedy did not advise him of the risk of the loss of the kidney nor explain the alternative ways of performing biopsies. The plaintiff further testified that he would not have consented to the biopsy had he known there was a risk of loss of the kidney. Dr. Kennedy testified that he did so inform the patient, and this testimony is substantially corroborated by the hospital record and by the prior conduct of the doctor in which he diagramed and explained in detail to Mr. Miller what was happening in his heart.
In performing the biopsy, the biopsy needle was inserted some 3 or 4 centimeters above the intended biopsy site. The kidney is encased in an outer capsule covering, inside of *275which there is an area called the cortex. The cortex surrounds the medulla which contains the nephrons, which are filtering, absorbing and secreting units doing the essential work of the kidney. The process of forming urine begins when arterial blood flows into a tuft of capillaries, called the glomerulus. The glomerulus is enclosed in a double membrane which leads into a tubule. The glomerulus, membranes and tubule form a single nephron. The glomerulus initially filters out some of the passing blood as do the membranes. The blood fluid then enters the tubule of the nephron where useful sugars, salts and water are reabsorbed by small capillaries and returned to the main bloodstream. The capillaries in turn secrete ammonia through the tubule wall into the fluid remaining which is flowing into the collecting tubule. The resulting comparatively small amount of waste is urine. The medulla area of the kidney contains approximately two and a half million nephrons. Inside the medulla area is the calyceal area, the collecting system of the kidney.
The plaintiff alleged that the biopsy needle was negligently inserted penetrating the calyceal system of the kidney causing damage and injury which eventually resulted in loss of the kidney. The defendant contended that the calyceal area was not punctured and that a small artery may have been injured. There is no dispute in the testimony that the loss of the kidney proximately resulted from the kidney biopsy, that the kidney was healthy prior to the biopsy and that the biopsy specimens were negative as to any of the conditions for which the biopsy was performed. The position of the plaintiff is that the defendant violated the standard of care.while the defendant states that the standard of care was met and claims that an unfortunate chance led to the result.
Following the biopsy, the plaintiff remained in the hospital from January 29,1970, until February 26,1970, suffering continual bleeding from his kidney and considerable pain. On February 26, 1970, Dr. Kennedy called upon another physician, Dr. Osborne, to examine Mr. Miller. In spite of *276his weakened condition and extensive bleeding, Mr. Millér was released from the hospital. Mr. Miller was again, at his own insistence, examined by Dr. Osborne; who removed blood clots from his bladder and returned him home. After the condition returned, Mr. Miller was again hospitalized on March 30, 1970. It was suggested that an operation be performed to see if the upper portion of the kidney, where the bleeding was taking place, could be surgically removed in an attempt to save the balance of the kidney. On April 4, the date set for the surgical procedure, Mr. Miller hemorrhaged, and the surgical procedure was expedited. Dr. Osborne performed this surgery, attempted to remove the upper portion of the kidney, but was unable to do so. Finally, he was required to do a complete nephrectomy, removing the entire kidney. Mr. Miller was released from the hospital on April 10,1970.
The plaintiff submits that the jury should have been instructed on res ipsa loquitur. The legal doctrine of res ipsa loquitur eliminates the need to prove negligence where (a) the apparatus which caused injury was under the exclusive control of the defendant, (b) the accident ordinarily would not have occurred unless the defendant had been negligent, and (c) the accident was not caused by any action of the plaintiff. Emerick v. Mayr, 39 Wn.2d 23, 234 P.2d 1079 (1951); Ewer v. Goodyear Tire & Rubber Co., 4 Wn. App. 152, 480 P.2d 260 (1971).
In ZeBarth v. Swedish Hosp. Medical Center, 81 Wn.2d 12, 18, 499 P.2d 1 (1972), as in this case, the instruction proposed defined circumstantial evidence, direct evidence and res ipsa loquitur.1 The plaintiff-appellant challenges *277the failure of the trial court to give this instruction claiming that the evidence made the instruction imperative. We agree that, under ZeBarth, the instruction should have been given. ZeBarth v. Swedish Hosp., in adopting the classic statement respecting res ipsa loquitur as applied to medical malpractice from Horner v. Northern Pac. Beneficial Ass’n Hosps., Inc., 62 Wn.2d 351, 382 P.2d 518 (1963), observed that there must be exclusive control of the instrumentality in the defendant and no voluntary participation or contribution by the plaintiff to the acts producing the injury. If such circumstances exist, then negligence may be deduced2 without further proof in three situations: (1) where the act causing the injury is so obviously negligent that negligence may be inferred as a matter of law, (2) when people would know from experience that the result would not have happened without negligence, (3) when a physician testifies that the bad result would not have occurred if proper care had been used. In this case, the doctor had exclusive control of the instrumentality, and the patient did not participate in the procedure. The circum*278stances present the inquiry whether an instruction on res ipsa loquitur should have been given. It cannot be said from the vantage point of an unskilled person that the insertion of a biopsy needle into the calyceal area was so palpably negligent that an inference of negligence follows, nor can it be said that the general experience of most people indicates this would not have happened without negligence.
This leaves only the inquiry whether the third situation as recognized under Washington law was present, to wit, an instruction should be given on res ipsa loquitur when medical doctors testify that the injury would not have happened but for some negligent action on the part of the treating physician. ZeBarth v. Swedish Hosp. Medical Center, supra at 19. The testimony of the doctors called as witnesses is in conflict. However, the jury was free to believe the testimony of one doctor and disregard the testimony of all the others. The testimony of the medical witness testifying on behalf of the plaintiff was such that the trier of the fact could deduce from that testimony that the defendant was negligent. The law concerning the propriety of instructing on res ipsa loquitur has been the subject of controversy as reflected in ZeBarth v. Swedish Hosp. Medical Center, supra; Zukowsky v. Brown, 79 Wn.2d 586, 488, P.2d 269 (1971); Douglas v. Bussabarger, 73 Wn.2d 476, 438 P.2d 829 (1968); and Pederson v. Dumouchel, 72 Wn.2d 73, 431 P.2d 973, 31 A.L.R.3d 1100 (1967). The currently prevailing trend of the Washington cases would instruct the jury that it could infer negligence when the plaintiff’s evidence supports the deduction that the injury would not have occurred otherwise.3 Siegler v. Kuhlman, 81 Wn.2d *279448, 502 P.2d 1181 (1972). They were not so instructed here. As stated in ZeBarth on page 22:
Res ipsa loquitur does not, and did not here, operate to deprive defendant hospital of its defense on the merits. Inferences of negligence arising from the doctrine and evidence were met with persuasive evidence to the contrary. But, although defendant presented weighty, competent and exculpatory proof of due and reasonable care and prudence, the ultimate issue of fact was one for the jury to decide.
An inference that negligence caused the injury to the patient may follow from the testimony of the plaintiffs’ medical witness, and Washington law4 entitled the plaintiff to an instruction that the jury could make that inference.
The trial court instructed the jury:
The law does not hold that physicians or surgeons guarantee results, nor does it require that the result of their treatment be what is desired.
The instruction was proper under the law when considered in the context of all the instructions. A bad result is not, of itself, evidence of negligence. Teig v. St. John’s Hosp., 63 Wn.2d 369, 387 P.2d 527 (1963); Rundin v. Sells, 1 Wn.2d 332, 95 P.2d 1023 (1939); Brant v. Sweet Clinic, 167 Wash. *280166, 8 P.2d 972 (1932); Hoffman v. Watkins, 78 Wash. 118, 138 P. 664 (1914). A physician, unless he so contracts, does not warrant or guarantee that an illness or disease will be cured. Eckleberry v. Kaiser Foundation N. Hosps., 226 Ore. 616, 359 P.2d 1090, 84 A.L.R.2d 1327 (1961); Derr v. Bonney, 38 Wn.2d 678, 231 P.2d 637, 54 A.L.R.2d 193 (1951); Fritz v. Horsfall, 24 Wn.2d 14, 163 P.2d 148 (1945). A doctor is neither an insurer that health will return to a patient nor should liability be imposed upon a doctor for an unfavorable, unforeseeable outcome which was not the result of negligence. Nelson v. Murphy, 42 Wn.2d 737, 258 P.2d 472 (1953); Crouch v. Wyckoff, 6 Wn.2d 273, 107 P.2d 339 (1940). The law does not hold a physician to a standard of infallibility. Hunt v. Bradshaw, 251 F.2d 103 (4th Cir. 1958).
The instruction is likewise challenged which read:
A physician is not liable for an honest error of judgment if, in arriving at that judgment, the physician exercised reasonable care and skill, within the standard of care he was obliged to follow.
The efforts of a physician may be unsuccessful or the exercise of one’s judgment be in error without the physician being negligent so long as the doctor acted within the stand ard of care of his peers. Dinner v. Thorp, 54 Wn.2d 90, 338 P.2d 137 (1959). A doctor is liable only for misjudgment when he arrived at such judgment through a failure to act in accordance with the care and skill required in the circumstances. A mistake is not actionable unless it is shown to have occurred because the doctor did not perform within the standard of care of his practice. Huffman v. Lindquist, 37 Cal. 2d 465, 234 P.2d 34, 29 A.L.R.2d 485 (1951); Norden v. Hartman, 134 Cal. App. 2d 333, 285 P.2d 977 (1955); Skeffmgton v. Bradley, 366 Mich. 552, 115 N.W.2d .303 (1962); Marsh v. Pemberton, 10 Utah 2d 40, 347 P.2d 1108 (1959). This instruction also was appropriate as an abstract statement of the law.
The plaintiff has objected to the instruction given on informed consent claiming it is inadequate under the cri*281teria laid down by ZeBarth v. Swedish Hosp. Medical Center, 81 Wn.2d 12, 499 P.2d 1 (1972), wrongfully places the burden of proving the failure to inform upon the plaintiff and wrongfully imposes on the plaintiff the obligation to prove by medical testimony a breach of a medical standard of disclosure. The plaintiff claims his proposed instruction on informed consent should have been given. We have commented upon many of the cases in this area in the foregoing opinion of Holt v. Nelson, 11 Wn. App. 230, 523 P.2d 211 (1974). In 1972 at the time ZeBarth v. Swedish Hosp. was being decided, Canterbury v. Spence, 464 F.2d 772 (D.C. Cir. 1972), Cobbs v. Grant, 8 Cal. 3d 229, 502 P.2d 1, 104 Cal. Rptr. 505 (1972), and Wilkinson v. Vesey, 110 R.I. 606, 295 A.2d 676 (1972), as well as other cases, were also in the process of decision. We deem it appropriate to review the plaintiff’s assignment of error guided primarily by the pronouncement of our highest court in ZeBarth but also to take notice of the decisions reached in other jurisdictions which enlighten this area. We review the instruction given, and the instruction proposed cognizant of the fact that at the time that this case was in trial in 1972, few of the decisions which now reflect the direction of this developing area of the law had yet been published. (Appendix I reflects the plaintiff’s proposed instruction and the court’s instruction. Both contain misleading flaws and neither is approved in toto.) It is suitable that the area be reevaluated and reconciled within the extent of our authority. See Greene v. Rothschild, 68 Wn.2d 1, 402 P.2d 356, 414 P.2d 1013 (1965); Stratton v. Department of Labor & Indus., 7 Wn. App. 652, 501 P.2d 1072 (1972).
The contest over whether the failure to inform a patient of the material risks of a medical procedure constitutes an assault upon the patient or a negligent breach of a physician’s duty to acquaint the patient with the perils of each medical course of action has been laid to rest. The performance of an operation without first obtaining any consent thereto may fall within the concepts of assault and *282battery as an intentional tort, but the failure to tell the patient about the perils he faces is the breach of a duty and is appropriately considered under negligence concepts. Cobbs v. Grant, supra at 240; Wilkinson v. Vesey, supra at 620; ZeBarth v. Swedish Hosp. Medical Center, supra at 23, 29. Due care requires the physician to alert the patient to abnormalities in his body. Canterbury v. Spence, supra at 781. As stated in Wilkinson on page 620:
The prevailing view, however, classifies the physician’s duty in this regard as a question of negligence because of the absence of the elements of any wilful intent by the physician to injure his patient.
The relationship between a doctor and his patient is one of trust calling for a recognition by the physician of the ignorance and helplessness of the patient regarding his own physical condition. Canterbury v. Spence, supra at 781. The duty of the doctor to inform the patient is a fiduciary duty. Hunter v. Brown, 4 Wn. App. 899, 905, 484 P.2d 1162 (1971), aff’d, 81 Wn.2d 465, 502 P.2d 1194 (1972); Mason v. Ellsworth, 3 Wn. App. 298, 308, 474 P.2d 909 (1970). The patient is entitled to rely upon the physician to tell him what he needs to know about the condition of his own body. The patient has the right to chart his own destiny, and the doctor must supply the patient with the material facts the patient will need in order to intelligently chart that destiny with dignity. Canterbury v. Spence, supra at 782.
The scope of the duty to disclose information concerning the treatment proposed, other treatments and the risks of each course of action and of no treatment at all is measured by the patient’s need to know.5 The inquiry as to each item of information which the doctor knows or should know about the patient’s physical condition is “Would the patient as a human being consider this item in choosing his or her *283course of treatment?”6 Cobbs v. Grant referring to the Canterbury case states on page 243:
The court in Canterbury v. Spence, supra, 464 F.2d 772, 784, bluntly observed: “Nor can we ignore the fact that to bind the disclosure obligation to medical usage is to arrogate the decision on revelation to the physician alone. Respect for the patient’s right of self-determination on particular therapy demands a standard set by law for physicians rather than one which physicians may or may not impose upon themselves.” Unlimited discretion in the physician is irreconcilable with the basic right of the patient to make the ultimate informed decision regarding the course of treatment to which he knowledgeably consents to be subjected.
Indeed, it is the prerogative of the patient to choose his treatment. A doctor may not withhold from the patient the knowledge necessary for the exercise of that right. Without it, the prerogative is valueless. Canterbury v. Spence, supra at 781, 782, 786.
The burden of proving that a physician failed to inform the plaintiff-patient of the available courses of treatment or failed to warn of the consequential hazards of each choice of treatment is on the plaintiff. It is the plaintiff who must initially establish the existence of the elements of an action based on the informed consent doctrine, i.e., the existence of a material risk unknown to the patient, the failure to disclose it, that the patient would have chosen a different course if the risk had been disclosed and resulting injury. Canterbury v. Spence, supra at 791; Mason v. Ellsworth, supra at 312; Trogun v. Fruchtman, 58 Wis. 2d 596, 604, 207 N.W.2d 297, 314 (1973). The burden of proving *284a.defense when failure to disclose has been established is on the doctor. Canterbury v. Spence, supra at 791; Cobbs v. Grant, supra at 245. Trogun on page 604 places the burden of proof upon the parties as follows:
We conclude that the burden of proof is on the plaintiff to establish a physician’s failure to disclose particular risk information in connection with contemplated treatment, the patient’s lack of knowledge of that risk and the adverse effects upon him which followed that treatment. . . . Once the plaintiff has established a prima facie showing of a failure of the physician to inform the patient, the physician must come forward with his explanation of the reasons for not so informing the patient, including evidence that such advice was not customarily given.
(Footnotes omitted.)
Those elements which are the province of the medical profession must be established by the testimony of medical experts in the field of inquiry. Thus, the existence of the risks and alternatives which were present in the particular physical condition would be beyond the knowledge of the layman and would have to be established by medical testimony. On the other hand, those matters which are not within the special province of the training and experience of doctors may be established by the testimony of any witness with knowledge of the particular inquiry, such as whether the patient knew of the risk or whether the average patient would consider the risk in making a decision. Trogun v. Fruchtman, supra at 604. There is no need to prove what other doctors might tell their patients in similar circumstances.7 The doctor has a duty to disclose the *285material risks as a matter of law.8 The testimony of medical experts is not necessary to establish the duty to disclose that which the law requires. Once the existence of a risk has been established by expert medical testimony, there is no need to take the next step and also prove by expert medical testimony that the doctor should have told the patient about the risk.9 Once it has been established by *286expert medical testimony that a risk existed, then the existence of the risk is the patient’s business; and it is not for the medical profession to establish a criteria for the dissemination of information to the patient based upon what doctors feel the patient should be told. Canterbury v. Spence, 464 F.2d 772 (D.C. Cir. 1972); Mason v. Ellsworth, supra. See also Comment, A New Standard for Informed Consent in Medical Malpractice Cases — The Role of the Expert Witness, 18 St. Louis Univ. L.J. 256 (1973). The patient has a right to know and the doctor has the duty to inform the patient whether the doctor wants to or not. The fiduciary duty of the doctor requires disclosure. There is no room for paternalism or for overprotectiveness. Getchell v. Mansfield, 260 Ore. 174, 182, 489 P.2d 953, 957 (1971), said:
We hold, therefore, that a plaintiff who alleges that a physician failed to warn him of material risks inherent in his treatment, and to advise him of feasible alternatives, need not produce expert medical testimony that it is the custom of physicians in the same or similar localities to give such warnings in comparable cases. The duty to warn and to advise of alternatives does not arise from and is not limited by the custom of physicians in the locality. Rather, it exists as a matter of law if (1) the risk of injury inherent in the treatment is material; (2) there are feasible alternative courses available; and (3) *287the plaintiff can be advised of the risks and alternatives without detriment to his well-being. If there is evidence tending to prove all these elements, the plaintiff is entitled to have his case submitted to the jury under proper instructions. In most cases, expert medical testimony will be necessary to establish each of the three elements.
Harper and James write forcefully that there should be no need in most cases for expert medical testimony to establish that disclosure of certain risks and alternatives is the customary medical practice:
“Since the courts quite rightly recognize room for a doctor’s therapeutic discretion in exercising his duty of disclosure, expert evidence of what is proper medical practice in that respect is relevant and is everywhere received. This is as it should be. But courts have generally gone much further and have required medical evidence that it is local professional practice to make the disclosure in question before a jury may find a doctor negligent in failing to make it, even where the treatment was an ‘elective’ one presenting no emergency.
“Such a requirement in these circumstances is, it is submitted, an unwarranted abdication of responsibility and of the individual’s right to make an informed choice, to the medical profession. * * 2 Harper and James, Law of Torts, 60-61 (1956, Supp 1968).
The patient is endowed with the right to know each hazard which the usual person would utilize in reaching his decision. When a reasonable person in the patient’s position probably would attach significance to the specific risk in deciding on treatment, the risk is material and must be disclosed. Canterbury v. Spence, supra at 787. Wilkinson v. Vesey, 110 R.I. 606, 627, 295 A.2d 676, 689 (1972), discusses materiality as follows:
[M] ateriality is to be the guide. It is our belief that, in due deference to the patient’s right to self determination, a physician is bound to disclose all the known material risks peculiar to the proposed procedure. Materiality may be said to be the significance a reasonable person, in what the physician knows or should know is his patient’s position, would attach to the disclosed risk or risks in *288deciding whether to submit or not to submit to surgery or treatment.
(See Appendix II.)
Situations may be envisioned where the disclosure of a risk to a patient would be detrimental to the patient. The existence of such a situation is a matter of defense for the doctor. The doctor may present evidence to justify the failure to disclose by his own testimony or by the testimony of other lay or expert witnesses. The doctor may establish the existence of a standard of nondisclosure by medical experts in his field or practice, but it is for the jury to accept or reject whether any standard of nondisclosure should deprive a patient of his right of self-determination. The situations where there was either no requirement of disclosure or where there was a reason for nondisclosure have been illustrated in Holt v. Nelson, 11 Wn. App. 230, 523 P.2d 211 (1974).10 Included are mental incompetence, emergencies, and potential physical trauma or mental disturbance to the patient. Canterbury v. Spence, supra; Cobbs v. Grant, 8 Cal. 3d 229, 245, 502 P.2d 1, 12, 104 Cal. Rptr. 505 (1972). A review of the defenses reveals that the validity of a defense is considered from the standpoint of concern for the well-being of the patient.
The jury is capable of deciding whether the doctor did not tell the patient about something that should have been revealed. The jury does not need testimony from physicians about the norm of disclosure in the community. The usual conduct of doctors in this matter is not relevant to the establishment of the liability which is imposed by law. The jury, as lay people, are equipped to place themselves' in the position of a patient and decide whether, under the circum*289stances, the patient should have been told. Wilkinson v. Vesey stated on page 625:
The jury can decide if the doctor has disclosed enough information to enable the patient to make an intelligent choice without the necessity of the plaintiff’s expert. The plaintiff, of course, must present evidence as to the undisclosed facts and their materiality. If the jury finds the undisclosed information immaterial, the doctor has acted reasonably in withholding it. If it finds the nondisclosure is material, the doctor may have acted unreasonably and will be held liable for his failure to obtain the patient’s informed consent.
An instruction outlining the elements of the negligence doctrine of “informed consent” should set forth that it is the duty of a physician or surgeon to disclose to a patient all relevant, material information the patient will need to make an informed decision on whether to consent to or reject the proposed treatment or operation. The jury should also be instructed that the plaintiff-patient must prove by a preponderance of the evidence that (1) the physician failed to inform the patient of a material risk involved in submitting to the proposed course of treatment; (2) the patient consented to the proposed treatment without being aware of or fully informed of the material risks of each choice of treatment and of no treatment at all; (3) a reasonable, prudent patient probably would not have consented to the treatment when informed of the material risks; and (4) the treatment chosen caused injury to the patient. It is also appropriate to instruct the jury that in the event a patient has consented to a proposed treatment or operation, a failure of the physician or surgeon to fully inform the patient of all of the material risks present in his medical situation before obtaining such consent is negligence; and a physician or surgeon is liable for any injury proximately resulting from the treatment if a reasonably prudent person in the patient’s position would not have consented to the *290treatment if adequately informed of all the significant perils.11
The instruction given by the court apprised the jury that the physician must disclose all material facts to the patient. However, the instruction was misleading in emphasizing that the duty to inform existed regardless of negligence or the exercise of due care by the physician “in the procedure itself” without making it clear also that the duty to inform of the risks inherent in the treatment existed as a matter of law. The small but important transgression of the instruction is one of misdirection. The instruction also stressed that the plaintiff was required to prove that he, the plaintiff-patient, would not have consented to the treatment had he been fully informed; while the proper approach requires the plaintiff to prove instead that a reasonable person in the plaintiff-patient’s position would not have consented. See Comment, Informed Consent: Alternatives for Illinois, 4 Univ. of Ill. L.F. 739 (1973). The instruction incorrectly stated the precepts of the law of informed consent. The plaintiff is entitled to a new trial with revised instructions given on res ipsa loquitur and informed consent.
*291Since a new trial is indicated, we will indicate our views on questions which might arise again. Both of the assignments of error relating to the exclusion of exhibits were unsupported by cited authority and, therefore, need not have been considered unless meritorious on their face. Myers v. Harter, 76 Wn.2d 772, 459 P.2d 25 (1969); Northern State Constr. Co. v. Robbins, 76 Wn.2d 357, 457 P.2d 187 (1969); Brown v. Quick Mix Co., 75 Wn.2d 833, 454 P.2d 205 (1969); Myers v. Western Farmers Ass’n, 75 Wn.2d 133, 449 P.2d 104 (1969). Both exhibits were offered to impeach the testimony of the defendant-doctor. One excluded exhibit was a letter to the defendant-doctor from the witness Dr. Hickman which discussed the procedure followed by the defendant-doctor in the kidney biopsy. Such an exhibit could not be offered for purposes of impeachment of the defendant-doctor even though the letter was inconsistent with his later testimony since the letter did not contain his statements and, therefore, did not contain inconsistent pronouncements of the person whose credibility was sought to be impeached. The letter, therefore, contained merely the contradictory statements of another, would-be hearsay, and not available for impeachment purposes. As noted in Jacqueline’s Washington, Inc. v. Mercantile Stores Co., 80 Wn.2d 784, 498 P.2d 870 (1972), impeaching evidence affects only the credibility of the witness and is incompetent to prove the substantive facts encompassed therein. The effort to introduce the letter was an impermissible attempt to rebut the testimony of the defendant-doctor through impeachment. The other excluded exhibit contained the handwritten answers to the interrogatories proposed to the defendant-doctor. Nothing in that document was inconsistent with the answers given to the interrogatories except as admitted by the doctor. The trial court was within its discretion in excluding the exhibit as cumulative.
The trial court did not submit the issue of post-biopsy care to the jury on the ground that the evidence was insufficient to establish the standard of care required as to the post-biopsy treatment “coupled with requisite evidence *292showing a failure of the standard, a breach of the standard as a basis of liability, . . .” We have reviewed the record and concur with the trial court’s ruling that the evidence must be found wanting on that issue. Absent special exceptions or situations, a plaintiff-patient must establish the standard of professional practice at the time of the alleged injury by the testimony of the professional equals of the defendant-physician, a failure to meet that standard and resulting injury to himself. Hayes v. Hulswit, 73 Wn.2d 796, 440 P.2d 849 (1968); Douglas v. Bussabarger, 73 Wn.2d 476, 438 P.2d 829 (1968); Pederson v. Dumouchel, 72 Wn.2d 73, 431 P.2d 973, 31 A.L.R.3d 1100 (1967). The physicians who testified were not interrogated directly on this aspect of the case, and our attention has not been called to any evidence that would establish this contention. CAROA 42(g) (ii) reads:
Under this heading the following shall be included: A brief statement of the nature of the case; a short resume of the pleadings and proceedings; the nature of the judgment or appropriate ruling or order from which the appeal is taken; a clear and concise statement of the facts appropriate to an understanding of the nature of the controversy, with page references to the record.
We are not referred to any page in the record containing testimony establishing the post-biopsy standard of care or any breach thereof. We conclude from our review of the record and the absence of reference pursuant to the rule that such evidence does not exist. See State v. Day, 7 Wn. App. 965, 971, 503 P.2d 1098 (1972).
Reversed and remanded.
Horowitz and Farris, JJ., concur.
Petition for rehearing denied July 18, 1974.
Review granted by Supreme Court October 10, 1974.
Appendix I
The plaintiff’s proposed instruction reads:
You are instructed that a patient has the right to determine what shall be done with his own body. A surgeon must obtain from the patient consent to perform a surgical procedure, such as a kidney biopsy. The consent of the patient must be an informed consent, that is, the physician must inform the patient of all material facts which are necessary to form the basis of an intelligent consent by the *293patient, and, in that regard, must inform him of the nature and consequences of the procedure and the reasonably foreseeable risks. If the patient inquires further as to any or all risks involved, the physician must make a complete disclosure of all facts and risks. Surgery performed, without disclosure by the surgeon as above described, constitutes an assault and battery. If you find from the evidence that the defendant physician failed to properly inform the plaintiff as above described, and further find that the plaintiff would not have consented to the surgical procedure if he had been informed, and that the plaintiff was injured as a result of submitting to the procedure, then you should find the defendant liable to the plaintiff for the injuries and damages resulting from said surgical procedure.
The court’s instruction reads:
Under the legal doctrine of “informed consent,” a patient may recover from a physician for damages proximately caused by a procedure performed without the patient’s “informed consent,” irrespective of any negligence or lack of negligence of the physician in the procedure itself.
In order to recover on this basis in this case, plaintiff must prove by a preponderance of the evidence:
1. That he was not informed of a reasonably foreseeable risk or that he inquired of defendant as to all risks and was not informed thereof;
2. That he would not have consented to the procedure had he been so informed;
3. That he has been injured as a proximate result of the procedure.
Appendix II
The Statement of a Patient’s Bill of Rights as promulgated in 1972 by the American Hospital Association includes the following provisions:
1. The patient has the right to considerate and respectful care.
2. The patient has the right to obtain from his physician complete current information concerning his diagnosis, treatment, and prognosis in terms the f^atient can be reasonably expected to understand. When it is not medically advisable to give such information to the patient, the information should be made available to an appropriate person in his behalf. He has the right to know, by name, the physician responsible for his care.
3. The patient has the right to receive from his physician information necessary to give informed consent prior to the start of any procedure and/or treatment. Except in emergencies, such information for informed consent should include but not necessarily be limited to the specific procedure and/or treatment, the medically significant risks involved, and the probable duration of incapacitation. Where medically significant alternatives for care or treatment exist, or when the patient requests information concerning medical altematives, the patient has the right to such information. The patient also has the right to know the name of the person responsible for the procedures and/or treatment.
*2944. The patient has the right to refuse treatment to the extent permitted by law and to be informed of the medical consequences of his action.
8. The patient has the right to obtain information as to any relationship of his hospital to other health care and educational institutions insofar as his care is concerned. The patient has the right to obtain information as to the existence of any professional relationships among individuals, by name, who are treating him.
9. The patient has the right to be advised if the hospital proposes to engage in or perform human experimentation affecting his care or treatment. The patient has the right to refuse to participate in such research projects.
10. The patient has the right to expect reasonable continuity of care. He has the right to know in advance what appointment times and physicians are available and where. The patient has the right to expect that the hospital will provide a mechanism whereby he is informed by his physician of the patient’s continuing health care requirements following discharge.