OPINION
GEORGE C. HANKS, JR., Justice.Thao Chau and Ha Dien Do, individually and as next friend of their minor children, S.D. and H.D. (collectively referred to as “the Dos”), appeal the trial court’s order granting Jefferson Riddle, M.D. and Greater Houston Anesthesiology, P.A.’s (“GHA”) motion for summary judgment and dismissing the Dos’ claims against them. In five issues, the Dos argue that (1) the trial court erred in striking their expert’s affidavit and their second supplemental designation of expert witnesses; (2) the trial court erred in striking two paragraphs from another expert’s affidavit; (3) the trial court erred in overruling their objections to the affidavits filed by two defense experts; and (4) the trial court erred in granting Riddle and GHA’s motion for summary judgment and dismissing the Dos’ claims. We affirm.
Background
On October 29, 2001, Dr. Jefferson Riddle was an on-call anesthesiologist at Memorial Southwest Hospital. On this same day, Thao Chau, pregnant with twins, went into labor at Memorial Southwest and remained in labor until the morning of October 30, 2001. Ms. Chau’s obstetrician, Dr. Le, decided to perform an emergency cesarean section, and Dr. Riddle was called to provide anesthesia for Ms. Chau during the surgery. After an unsuccessful attempt to use epidural anesthesia, Dr. Riddle administered general anesthesia to Ms. Chau.
At 2:46 a.m. on October 30, 2001, S.D. was delivered “floppy,” without any tone and very pale. The neonatal team took over S.D.’s care, but, after failing to resuscitate him, Dr. Le asked Dr. Riddle to assist. Dr. Riddle proceeded to intubate S.D. Afterwards, Dr. Riddle, using a stethoscope, listened and reported hearing breath sounds in S.D.’s chest. He also reported seeing S.D.’s chest rise. At this time, the neonatal team proceeded with the resuscitation, and Dr. Riddle returned to Ms. Chau, who was experiencing bleeding from a uterine atony.1
S.D.’s endotracheal tube was secured by a nurse on the neonatal team. Two members of S.D.’s neonatal team reported hearing breath sounds in S.D.’s chest, although one other member reported not hearing breath sounds. The neonatal team started chest compressions as S.D. remained unresponsive. Dr. Ruiz-Puyana, an on-call neonatologist, arrived in the operating room approximately 13 to 15 minutes after S.D. was delivered and took over efforts to resuscitate him. Dr. Ruiz-Puya-na reported not hearing breath sounds and found that the intubation tube was lodged in S.D.’s esophagus. Dr. Ruiz-Puyana ex-tubated and re-intubated S.D., at which time his color improved, but he still did not have a heart rate. Dr. Ruiz-Puyana then administered medications and afterwards detected a heart rate. S.D. suffered permanent brain damage due to a lack of oxygen.
On July 22, 2002, the Dos brought a healthcare liability suit against Dr. Riddle alleging medical malpractice in his care of S.D. The suit also named GHA, Riddle’s *703employer, as being vicariously liable for the alleged negligence.2
The trial court granted Riddle and GHA’s motion to limit expert testimony to one witness in each area of expertise. The Dos de-designated Dr. Scott Reeves and left Dr. Ronald Katz as their testifying anesthesiology expert.
Riddle and GHA moved for both traditional and no-evidence summary judgments. The motion asserted that there was no evidence that Dr. Riddle was negligent in his care of S.D. and, in the alternative, if there was a fact issue on this claim, Dr. Riddle should prevail under a traditional summary judgment because he proved his Good Samaritan affirmative defense.3
In response to the summary judgment motion, the Dos submitted two affidavits from Dr. Reeves, their previously de-des-ignated expert. Dr. Reeves testified that an “on call” anesthesiologist expects emergencies, which include intubating newborns. Dr. Reeves further testified that Dr. Riddle cannot prevail on the Good Samaritan defense because he became associated with Dr. Le when Le asked him to assist in the caesarian section; therefore, Dr. Riddle became S.D.’s physician while intubating him. Also, despite what Dr. Riddle asserted in his affidavit, Dr. Reeves testified that Dr. Riddle would be entitled to remuneration for S.D.’s intubation, which would also fall outside the Good Samaritan statute. The Dos filed a second supplemental designation of expert witnesses that re-designated Dr. Reeves as an additional anesthesiology expert.
Dr. Riddle and GHA moved to strike Dr. Reeves’s affidavits as well as the Dos’ second supplemental designation of expert witnesses. The Dos did not respond to the motion, and it was granted. Dr. Riddle and GHA then filed a motion to strike paragraphs six and nine of Dr. Katz’s affidavit for not being probative on the issue of whether Dr. Riddle was entitled to receive remuneration for his services of S.D. Again, the Dos did not respond, and the trial court granted the motion. Finally, at a hearing on the motion for summary judgment, the trial court granted summary judgment to Dr. Riddle and GHA, and the case was dismissed with prejudice.
Expert Testimony
In issues one and two, the Dos argue that the trial court erred in striking their second amended designation of expert witnesses, Dr. Reeves’s affidavits, and paragraphs six and nine of Dr. Katz’s affidavit. In issues three and four, the Dos contend that the trial court erred in overruling their objections to the affidavits filed by two defense experts.
Designation of Expert Witnesses
Exclusion of expert testimony is reviewed under an abuse of discretion standard. McIntyre v. Ramirez, 109 S.W.3d 741, 749 (Tex.2003). A trial court abuses its discretion if it acts arbitrarily, unreasonably, or without reference to guiding rules or principles. Powers v. Mem’l Hermann Hosp. Sys., 81 S.W.3d 463, 465 (Tex.App.-Houston [1st Dist.] 2002, pet. denied). Under an abuse of discretion standard, a reviewing court may *704not substitute its own judgment for that of the trial court. Bowie Mem’l Hosp. v. Wright, 79 S.W.3d 48, 52 (Tex.2002).
Unless otherwise ordered by the court, a party must designate experts within a specified time frame. See Tex.R. Civ. P. 195.2. A party has a duty to amend or supplement responses to discovery when the party learns that the discovery was incomplete or incorrect. See Tex.R. Civ. P. 193.5. Testimony not disclosed in response to discovery is permitted upon a showing of good cause or if its use would not unfairly surprise or prejudice the other party. Tex.R. Civ. P. 193.6. Exclusion of a witness for a party’s failure to timely or properly designate a witness is a sanction available to the trial court. Tex.R. Civ. P. 193.6.
Here, the modified docket control order indicated that only one expert per specialty could be designated. Accordingly, the Dos designated Dr. Ronald Katz as their testifying anesthesiology expert. In their second supplemental designation of expert witnesses, the Dos re-designated Dr. Reeves without de-designating Dr. Katz. The Dos filed no response to Dr. Reeves and GHA’s motion to strike; therefore, we hold that the trial court acted within its discretion when it struck Dr. Reeves as a sanction for the Dos’ failure to timely or properly designate him. See id.
Summary Judgment Evidence
In addition to striking their expert designation, the trial court struck Dr. Reeves’s affidavits and two paragraphs in Dr. Katz’s affidavit that were filed in response to Dr. Riddle’s and GHA’s motion for summary judgment.
To obtain reversal of a judgment based on error in the admission or exclusion of evidence, an appellant must show that the trial court’s ruling was in error and that the error was calculated to cause and probably did cause rendition of an improper judgment. Gee v. Liberty Mut. Fire Ins. Co., 765 S.W.2d 394, 396 (Tex.1989). The summary judgment rule provides that summary judgment proof must contain facts that would be admissible in evidence. United Blood Servs. v. Longoria, 938 S.W.2d 29, 30 (Tex.1997); see also Tex.R. Civ. P. 166a(f). To prove facts through an interested witness, the testimony must be uncontroverted, clear, positive, direct, credible, free from contradiction, and susceptible to being readily controverted. McIntyre, 109 S.W.3d at 749.
Dr. Reeves’s Affidavits
Dr. Riddle and GHA filed an objection to and a motion to strike the Dos’ summary judgment evidence. Specifically, they sought to strike Dr. Reeves’s two affidavits — Exhibit A, dated September 15, 2003, and Exhibit G, dated January 15, 2003. The objection was that neither affidavit would be admissible at trial in this case. See Tex.R. Civ. P. 166a(f); United Blood Servs., 938 S.W.2d at 30. They further objected that neither affidavit was adequate summary judgment evidence on causation. The Dos did not respond to the motion.
When the Dos filed their summary judgment response, Dr. Reeves was not their designated expert. The affidavit of an expert who is not properly designated may not be used as evidence in a summary judgment context. Cunningham v. Columbia/St. David’s Healthcare, 185 S.W.3d 7, 10-11 (Tex.App.-Austin, no pet.); Ersek v. Davis & Davis, P.C., 69 S.W.3d 268, 274 (Tex.App.-Austin 2002, pet. denied). Where the expert’s testimony will be excluded at trial on the merits, it will be excluded from a summary judgment proceeding. Ersek, 69 S.W.3d at 273. The affidavits were inadmissible as summary judgment proof per rule 166a(f)4 of the *705Texas Rules of Civil Procedure. Tex.R. Crv. P. 166a(f); see also Ersek, 69 S.W.3d at 271.
Accordingly, because Dr. Reeves was not properly designated, because we have already held that the trial court did not abuse its discretion in striking the Dos’ second supplemental designation in which they re-designated Dr. Reeves, and because Dr. Reeves would be unable to testify during the trial on the merits, we hold that the trial court did not abuse its discretion in striking Dr. Reeves’s affidavits filed in response to Dr. Riddle and GHA’s motion for summary judgment.5
We overrule issue one.
Dr. Katz’s Affidavit
In issue two, the Dos contend that the trial court erred in stinking paragraphs six and nine of Dr. Katz’s affidavit.
In seeking the protection of the Good Samaritan statute, Dr. Riddle testified that he was not entitled to receive payment for the services provided to S.D. He asserted that neither he nor anyone he was familiar with in Harris County would have been entitled to remuneration “under these circumstances.” In response, the Dos offered the affidavit of Dr. Katz, a board-certified anesthesiologist from California, to support their contention that Dr. Riddle was entitled to compensation. Dr. Riddle and GHA moved to have paragraphs six and nine struck from Dr. Katz’s affidavit for not being probative on the issue of whether Dr. Riddle was entitled to remuneration for the intubation of S.D. because they were eonclusory and Dr. Katz was not qualified to opine about the billing practices of a Houston-based anesthesiologist.
The paragraphs that were struck stated the following:
6. Anesthesiologists are hospital-based doctors, meaning we rarely have offices where we see patients, and usually our medical practice is at a hospital. When we render anesthesia services, we expect to be compensated, whether we perform those services “on call” or during the regular workday; it is our practice to charge (or for the hospital to charge if we are salaried and at a teaching facility) for those services.
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9. From the time that Dr. Riddle began providing the anesthesia for the cesarean section in this case, he became “associated with” the attending physician, Dr. Le. He became Dr. Le’s partner, associate or colleague on the Labor and Delivery team, and they had to work together for all the patients involved in the birth — the mother and the children. Both obstetrician and anesthesiologist in a C-section are treating both the mother and the child because whatever they do to the mother is also being done to and affects the child who is in that mother’s body, whether by administering drugs, providing oxygen, and the like. It is their job to care for both the mother and the child/children. So it is disingenuous for an anesthesiologist during a C-section to say he had no responsibility for the child, especially under the circumstances where there was no neonatologist present, the baby was in distress, he had undertaken to intubate the child, and his adult patient (the mother) was not in crisis. It is below the standard of care for an anes*706thesiologist providing anesthesia during a C-section to care for only the mother and not the child as well where the mother is medically stable. Caring for both is a juggling act the anesthesiologist must manage within the standards of care.
[S.D.] was and would have been Dr. Riddle’s responsibility in any event, as the “on call” anesthesiologist. If the mother had delivered without C-section, and the baby was not breathing, in the absence of a neonatologist, as the “on call” anesthesiologist, Dr. Riddle would likely have been called in specifically for the baby who didn’t have an established airway as the “on call” anesthesiologist.
Anesthesiologists routinely perform intubations for general anesthesia, and are often called to perform intubations or assist in difficult intubations, in an operating room or otherwise, because they are usually the most qualified to do so by experience and training. In these situations, anesthesiologists (or the hospital if they are in a teaching hospital and the anesthesiologists are salaried) commonly charge and are entitled to charge for these services. The intubation of [S.D.] is no different from the intubation of other patients in which anesthesiologists commonly charge and are entitled to charge for their services.
“The relevant standard for an expert’s affidavit opposing a motion for summary judgment is whether it presents some probative evidence of the facts at issue.” Ryland Group, Inc. v. Hood, 924 S.W.2d 120, 122 (Tex.1996). A conclusory statement of an expert witness is insufficient to create a question of fact to defeat summary judgment. McIntyre, 109 S.W.3d at 749. A party offering an expert’s affidavit must demonstrate that the witness “possesses special knowledge as to the very matter on which he proposes to give an opinion.” Gammill v. Jack Williams Chevrolet, Inc., 972 S.W.2d 713, 718 (Tex.1998).
Paragraph six of Dr. Katz’s affidavit states, in pertinent part, that, when an anesthesiologist renders anesthesia services, whether on call or during the regular workday, “it is our practice to charge for those services.” The testimony in paragraph nine states that Dr. Riddle became responsible for S.D. when he assumed the care of Mrs. Chau. As such, he was entitled to compensation for intubat-ing S.D. after birth.
While Dr. Katz purported to have personal knowledge of the facts recited in his affidavit, his statement regarding Dr. Riddle’s entitlement to compensation is a legal conclusion with no supporting facts or rationale. See McIntyre, 109 S.W.3d at 749 (holding that Maryland doctor not qualified to testify about “what’s ordinarily billed or what the law ordinarily allows people to recover for their medical services in the State of Texas”). Dr. Katz’s affidavit makes no claims that, within this particular locale, an anesthesiologist acting within the circumstances of these facts would have been entitled to compensation. See id. A conclusory statement of an expert is insufficient to create a question of fact to defeat a summary judgment. Id. Consequently, this testimony is not probative of the issue at hand, and, as such, the trial court did not abuse its discretion in striking it.
We overrule issue two.
Dr. Riddle’s Affidavit
In issue three, the Dos contend that the trial court erred in overruling their objections to Dr. Riddle’s affidavit offered in support of his contention that he was not entitled to remuneration for intu-bating S.D.
The Dos objected to paragraph six of Dr. Riddle’s affidavit where he stated that *707he “was only entitled to bill for and only did bill for the anesthesia services I provided to my patient, Thao Chau,” and that he was “not entitled to charge for the intubation of [S.D.] and was “only entitled to charge for the services directly related to the patient’s care and treatment.” The paragraphs in question stated as follows:
I was only entitled to bill for and only did bill for the anesthesia sendees I provided to my patient, Thao Chau. I would not ordinarily receive or ordinarily be entitled to receive remuneration under the above described circumstances for the emergency intubation of [S.D.] Neither myself nor anyone else that I am familiar with in Harris County would have charged a fee for the emergency intubation of [S.D.] or to any other person under the circumstances of this case. I did not charge for the intu-bation of [S.D.], I was not entitled to charge for the intubation of [S.D.], and I did not render the intubation related care to [S.D.] in expectation of compensation. This is not a situation for which I have ever or would ever charge for. As the only anesthesiologist administering anesthesia to Ms. Chau during her cesarean section, I am only entitled to charge for the services directly related to that patient’s care and treatment.
In their objection to the summary judgment evidence, the Dos asserted that (1) Dr. Riddle is not an attorney and, pursuant to Texas Rule of Evidence 702, is not qualified to comment on what he is “entitled to”; (2) his statement was conclusory; (3) he cannot testify as a lay witness under rule 701 because he has not demonstrated “what rational basis leads him to that conclusion”; and (4) the statement “under the circumstances of this case” is “deceptively vague.”
In McIntyre, the Texas Supreme Court held that “proof that Dr. McIntyre is not legally entitled to remuneration under any conceivable circumstance or theory is unnecessary.” McIntyre, 109 S.W.3d at 746 (emphasis added). A person seeking protection of the Good Samaritan statute must prove that he would neither ordinarily receive nor ordinarily be entitled to receive remuneration. Id. at 747. If a person presents evidence that he does not customarily receive payment under the circumstances in question, he can negate the first prong of section 74.001(d). Id. at 746.
Unlike Dr. Katz’s legal conclusion regarding billing practices, Dr. Riddle’s affidavit provides “supporting facts or rationale” for his statement that he does not ordinarily receive payment for and is not entitled to bill for S.D.’s intubation. See id. at 749. Furthermore, because McIntyre only requires that Dr. Riddle prove that he does not customarily receive payment under the circumstances in question, the Dos cannot prove that the alleged error was calculated to cause and probably did cause, rendition of an improper judgment. See Gee, 766 S.W.2d at 396. Finally, the Dos’ complaints regarding Dr. Riddle’s use of the term “under the circumstances of this case” are unfounded considering that the Good Samaritan statute uses the term “under such circumstances” and the McIntyre case refers to “under the circumstances in question.” See Tex. Civ. PRAC. & Rem.Code ANN. § 74.001(d); McIntyre, 109 S.W.3d at 746.
Accordingly, we overrule issue three.
Marie Walton’s Affidavit
In issue four, the Dos contend that the trial court erred in overruling their objections to Marie Walton’s affidavit where she testified that, as the director of operations for Preferred Healthcare Business Services — the company that provided billing services for Dr. Riddle and GHA— she knew that Dr. Riddle could only charge for the anesthesia he administered to his patient, Thao Chau.
*708The Dos objected to Walton’s affidavit for containing “several self-serving conclu-sory statements ... about ‘GHA’s billing guidelines’ and ‘applicable guidelines.’ However, none of those guidelines have been proved up as a business record, attached or even described, if indeed they exist.” They objected to the “rank hearsay,” and conclusory, self-serving affidavit. The paragraphs in question stated as follows:
The charge for anesthesia services provided to Thao Chau on October 30, 2001 was $734.50. Dr. Riddle charged only for the anesthesia services he provided to Thao Chau on October 20, 2001.
Pursuant to GHA’s billing guidelines, Dr. Riddle was the primary anesthesiologist providing anesthesia services to Thao Chau and may only charge for the anesthesia services he provided to Thao Chao, [sic]
Pursuant to such guidelines, Dr. Riddle did not submit a bill for the intubation of [S.D.] He would not be able to bill for the intubation of [S.D.] I am not familiar with anyone in Harris County who would send a bill for providing emergency care for [S.D.] under the circumstances of this case. An anesthesiologist would not ordinarily receive or ordinarily be entitled to receive payment under the circumstances in which the emergency care was provided to [S.D.]
Pursuant to the applicable billing guidelines, Dr. Riddle would not be entitled to payment for a procedure that was not related to his patient, Thao Chau, on October 30, 2001.
The Dos complain that (1) Walton is not an attorney and therefore not qualified to comment, as an expert, on what Dr. Riddle is entitled to charge; (2) she cannot comment, as a lay witness, because she “has not demonstrated to us what rational basis leads her to that conclusion”; and (3) the term “the circumstances of this case” is “deceptively vague.”
Walton testified that she has personal knowledge of the facts of this case and, as such, she can certainly testify to what Dr. Riddle’s ordinary billing practices are. Furthermore, as we held above, McIntyre only requires that Dr. Riddle prove that he does not customarily receive payment under the circumstances in question. Thus, the Dos cannot prove that the alleged error regarding Walton’s testimony regarding “entitlement” was calculated to cause, and probably did cause, rendition of an improper judgment. See Gee, 765 S.W.2d at 396. Finally, the Dos’ complaints regarding Walton’s use of the term “the circumstances of this case” are unfounded considering that the Good Samaritan statute uses the term “under such circumstances” and the McIntyre ease refers to “under the circumstances in question.” See Tex. Civ. Prac. & Rem.Code Ann. § 74.001(d); McIntyre, 109 S.W.3d at 746.
We overrule issue four.
Summary Judgment
In issue five, the Dos contend that the trial court erred in granting the motion for summary judgment and dismissing their claims. Dr. Riddle and GHA’s summary judgment consisted of (1) a traditional summary judgment in which they asserted that the Good Samaritan affirmative defense precluded recovery and (2) a no-evidence summary judgment in which they asserted that there was no evidence that Dr. Riddle had a duty to care for S.D., there was no evidence of a breach of the alleged duty, and there was no evidence that the breach of the alleged duty caused S.D.’s injuries.
Good Samaritan
In a traditional summary judgment, the movant bears the burden of proof. Tex.R. Civ. P. 166a(c); Roskey v. Tex. Health *709Facilities Comm’n, 639 S.W.2d 302, 303 (Tex.1982). All doubts concerning the existence of a genuine issue of fact must be resolved against the movant. Montgomery v. Kennedy, 669 S.W.2d 309, 311 (Tex.1984). Once the movant proves a right to a summary judgment, the burden shifts to the nonmovant to present evidence creating genuine issues of material fact. Phan Son Van v. Pena, 990 S.W.2d 751, 753 (Tex.1999). A defendant moving for summary judgment on an affirmative defense has the burden to establish conclusively that defense. McIntyre, 109 S.W.3d at 748.
Under certain circumstances, the Good Samaritan statute exempts a person who responds to a medical emergency from liability for ordinary negligence. The statute provides in relevant part:
Liability for Emergency Care
(a) A person who in good faith administers emergency care ... is not liable in civil damages for an act performed during the emergency unless the act is wilfully or wantonly negligent.
(b) This section does not apply to care administered:
(1) for or in expectation of remuneration; or
(2) by a person who was at the scene of the emergency because he or a person he represents as an agent was soliciting business or seeking to perform a service for remuneration.
(c) If the scene of an emergency is in a hospital or other health care facility or means of medical transport, a person who in good faith administers emergency care is not liable in civil damages for an act performed during the emergency unless the act is wilfully or wantonly negligent, provided that this subsection does not apply to care administered:
(1) by a person who regularly administers care in a hospital emergency room unless such a person is at the scene of the emergency for reasons wholly unrelated to the person’s work in administering health care; or
(2) by an admitting or attending physician of the patient or a treating physician associated by the admitting or attending physician of the patient in question.
(d) For purposes of Subsections (b)(1) and (c)(1), a person who would ordinarily receive or be entitled to receive a salary fee, or other remuneration for administering care under such circumstances to the patient in question shall be deemed to be acting for or in expectation of remuneration even if the person waives or elects not to charge or receive remuneration on the occasion in question.
(e) This section does not apply to a person whose negligent act or omission was a producing cause of the emergency for which care is being administered.
Tex. Crv. Prac. & Rem.Code Ann. § 74.001.
The Good Samaritan statute has separate provisions to apply depending on the physical location at which the emergency care was rendered. See id. § 74.001(a), (c). Here, the scene of the emergency was a labor and delivery room in a hospital. Accordingly, this case implicates section 74.001(c), which applies when the scene of the emergency is a hospital. See id. § 74.001(c). Dr. Riddle testified that he acted in good faith and without wilful or wanton negligence, and the Dos did not present any controverting evidence on this issue; therefore, Dr. Riddle is exempt from liability under section 74.001(c), unless he is excepted by some other provision of the statute.
*710Pre-existing- Relationship or Duty
The purpose of the Good Samaritan statute is to protect persons who respond to an emergency absent a preexisting relationship or duty to respond. See McIntyre, 109 S.W.3d at 747-48. While consent may be implied, the “on call” status of a physician does not automatically impose a duty. St. John v. Pope, 901 S.W.2d 420, 424 (Tex.1995).
The Dos contend that the duty of an anesthesiologist to a patient in the process of giving birth also extends to the unborn child. They offer the affidavit of Dr. Katz, which states that “it is foreseeable that an anesthesiologist may have to intubate a newborn when called to assist in a cesarean section,” and that, “from time to time,” an anesthesiologist is needed to intubate the newborn if he can do so because the mother is stable. In his deposition, Dr. Katz testified that, if Dr. Riddle found that he could not leave his patient to assist with the intubation, then he had no responsibility to the child. The Dos contend that Dr. Riddle owed a duty to S.D., and, as such, is precluded from seeking exemption from liability under the Good Samaritan statute.
Dr. Katz testified that Dr. Riddle could have chosen not to intubate S.D. In his affidavit, he testified that
Dr. Riddle was [S.D.’s] treating physician while intubating [S.D.] He could have refused to intubate him if the anesthetized mother was in crisis or medically unstable and he had to choose her. However, once he agreed to intubate [S.D.], laid hands on him, and undertook to intubate [S.D.], Dr. Riddle became one of [S.D.’s] physicians. It was Dr. Riddle’s responsibility to perform that intubation within the standard of reasonably prudent anesthesia care.
(Emphasis added.) These statements do not establish a pre-existing relationship or impart an affirmative duty on the part of Dr. Riddle to act. Rather, they seem to merely'give instances when the assistance of an anesthesiologist may be sought to resolve an emergency situation and suggest that any assistance on the anesthesiologist’s part is discretionary. As such, the Dos failed to establish a pre-existing relationship or an affirmative duty on the part of Dr. Riddle to act on behalf of S.D.
Emergency
The Dos contend that a lack of oxygen in a newborn may be a medical emergency, however, because the anesthesiologist can expect that this might happen and is trained to handle such a situation, then it is not a medical emergency for the purposes of the Good Samaritan statute. Just because an anesthesiologist has trained to respond to such emergencies does not make them any less of an emergency.
The Good Samaritan statute serves to shield from liability a person who acts without a pre-existing duty. See Tex. Civ. Prac. & Rem.Code Ann. § 74.001; see also McIntyre, 109 S.W.3d at 747. Even Dr. Katz acknowledged that a “patient who is not getting oxygen, or is getting little oxygen, is always an emergency.” Having already held that Dr. Riddle did not have a pre-existing relationship with S.D., we hold that S.D.’s status at birth created an emergency for Dr. Riddle within the Good Samaritan statute.
Expectation of Remuneration
The protection of the Good Samaritan statute is only available if the one rendering emergency care proves that he would not ordinarily receive or ordinarily be entitled to receive remuneration for such care. McIntyre, 109 S.W.3d at 747. The Dos asserted that Dr. Riddle was entitled to remuneration for S.D.’s intubation.
In his affidavit, Dr. Riddle stated the following:
*711I am not a physician who regularly administers care in the emergency room at Memorial Southwest Hospital or any other hospital. I was not an attending or admitting physician of Thao Chau. I was not an attending or admitting physician of [S.D.]. I was not a treating physician associated with Dr. Le.... I was not a treating physician associated with Dr. Ruiz-Puyana.
I was only entitled to bill for and only did bill for the anesthesia services I provided to my patient, Thao Chau. I would not ordinarily receive or ordinarily be entitled to receive remuneration under the above described circumstances for the emergency intubation of [S.D.], Neither myself nor anyone else that I am familiar with in Harris County would have charged a fee for the emergency intubation of [S.D.] or to any other person under the circumstances of this case. I did not charge for the intu-bation of [S.D.], I was not entitled to charge for the intubation of [S.D.], and I did not render the intubation related care to [S.D.] in expectation of compensation. This is not a situation for which I have ever or would ever charge for.
To prove facts through an interested witness, the testimony must be uncontrovert-ed, clear, positive, direct, credible, free from contradiction, and susceptible to being readily controverted. Tex.R. Civ. P. 166a(c); McIntyre, 109 S.W.3d at 749. The Dos objected to Dr. Riddle’s affidavit. The trial court, however, allowed the affidavit as well as the affidavit of billing specialist, Marie Walton, offered in support of Riddle’s proposition that he was not entitled to remuneration. Having already held that the trial court did not abuse its discretion in striking the Dos’ summary judgment evidence on this issue, we hold that Dr. Riddle’s summary judgment evidence conclusively established that he did not act for or in expectation of remuneration within the meaning of section 74.001(b)(1) and (d) of the Texas Civil Practice and Remedies Code.
Association
The Good Samaritan statute does not shield a treating physician associated by the admitting or attending physician of the patient in question from ordinary negligence during emergency care rendered to that patient in a hospital. Tex. Civ. Pra.c. & RemCode Ann. § 74.001(c)(2). The Dos claim that, because Dr. Riddle was working with Dr. Le, Ms. Chau’s obstetrician, he became “associated” within the meaning of section 74.001(c)(2) of the Good Samaritan statute. The patient in question is S.D. Dr. Le testified that he was the attending physician for Ms. Chau, but Dr. Ruiz-Puyana, the neonatologist, was the attending physician for S.D. Dr. Katz’s affidavit makes no contention that Dr. Riddle was, in any way, associated with Dr. Ruiz-Puyana. As such, we hold that Dr. Riddle was not associated with S.D.’s attending physician within the meaning of the Good Samaritan statute.
We hold that Dr. Riddle and GHA. conclusively established that Dr. Riddle is not excepted by any provision of the statute and is therefore entitled to the Good Samaritan affirmative defense. Having held that Dr. Riddle and GHA conclusively established their Good Samaritan affirmative defense, we need not evaluate their traditional and no-evidence summary judgment motions on negligence.
We overrule issue five.
Conclusion
We affirm the order of the trial court granting summary judgment and dismissing the Dos’ claims.
Justice KEYES, dissenting.
. In his affidavit, Dr. Riddle explained that a uterine atony is a potentially life-threatening condition that occurs “where there is excessive bleeding from the uterus due to the failure of the uterus to sufficiently contract after delivery.”
. Numerous healthcare providers were sued in addition to Riddle and GHA. This case has been severed from the remaining claims in the case.
. The Good Samaritan statute provides an affirmative defense against ordinary negligence for persons who administer emergency care, under specified circumstances. Tex. Civ. Prac. & Rem.Code § 74.001 Ann. The Legislature has amended the statute, effective September 1, 2003. Acts of June 1, 2003, 78th Leg., R.S., ch. 204, § 10.01, 2003 Tex. Gen. Laws 204. Because the amendments do not apply to our decision today, all statutory references are to the Code as it existed at the time that the care was rendered.
. Rule 166a(f) provides that supporting and opposing affidavits shall be made on personal *705knowledge, shall set forth such facts as would be admissible in evidence, and shall show affirmatively that the affiant is competent to testify to the matters stated therein. Tex.R. Civ. P. 166a(f).
. Despite filing several responses and supplemental responses to Dr. Riddle and GHA’s motion for summary judgment, the Dos never argued that the trial court arbitrarily enforced its docket control order.