Mercier, Judge.Rose Edokpolor died at Grady Memorial Hospital on July 28, 2008. Following her death, Edokpolor’s surviving relatives, Patrick Edokpolor and Linda Patrick (collectively, “appellants”), sued Grady Memorial Hospital Corporation and Shirley Singh, R. N. (collectively, “Grady”), for medical malpractice. Grady subsequently moved for summary judgment, arguing inter alia that appellants had failed to raise genuine issue of material fact as to causation. The trial court granted the motion, and appellants challenge that ruling on appeal. We affirm.[1] 1. Summary judgment is appropriate when “the pleadings, depositions, answers to interrogatories, and admissions on file, together with the affidavits, if any, show that there is no genuine issue as to any material fact and that the moving party is entitled to a judgment as a matter of law.” OCGA § 9-11-56 (c). We review the grant of summary judgment de novo, construing the evidence and all reasonable inferences in favor of the non-moving party. See Beasley v. Northside Hosp., 289 Ga. App. 685, 685-686 (658 SE2d 233) (2008).So viewed, the record shows that Edokpolor, who had a history of cardiac disease and other medical complaints, was admitted to Grady Memorial Hospital on May 17, 2008. She remained hospitalized, and on June 17, 2008, Edokpolor’s treating physicians determined that she needed a colonoscopy. Prior to the test, a doctor prescribed Golytely, a liquid bowel preparation medication. Although Golytely normally is taken by mouth, Edokpolor had a nasogastric-feeding tube (nose-to-stomach “NG” tube) in place, and the doctor ordered that the medication be administered through the “NG tube when started,” rather than orally. Despite this order, a Grady Hospital nurse gave the Golytely to Edokpolor by mouth throughout the day on June 17, 2008. At some point Edokpolor aspirated, resulting in a “code blue” that evening. Edokpolor died six weeks later. The death certificate listed “Aspiration Pneumonia” as the immediate cause of death.Appellants sued Grady Memorial Hospital Corporation and Shirley Singh, the nurse who administered the Golytely to Edokpolor, for medical malpractice. Pursuant to OCGA § 9-11-9.1 (a), appellants attached the affidavit of Kelly Thrasher, M. D., to their complaint.[2] Thrasher testified that the applicable standard of care required Singh and other nursing personnel to “follow the doctor’s orders to administer the Golytely through the NG tube rather than by mouth.” He asserted that their failure to do so was negligent and breached the standard of care. And he concluded that this negligence “proximately caused the death of Rose Edokpolor.” Grady moved for summary judgment on several grounds, including that appellants failed to show that the alleged negligence proximately caused Edokpolor’s death. Grady acknowledged Thrasher’s causation testimony, but characterized it as unsupported, conclusory, and insufficient to raise a genuine question of material fact. The trial court agreed and granted the motion. We find no error.“[A] plaintiff cannot recover for medical malpractice, even where there is evidence of negligence, unless the plaintiff establishes by a preponderance of the evidence that the negligence either proximately caused or contributed to cause plaintiff harm.” Zwiren v. Thompson, 276 Ga. 498, 500 (578 SE2d 862) (2003) (citations and punctuation omitted). To meet this burden, a medical malpractice plaintiff must present expert testimony “because the question of whether the alleged professional negligence caused the plaintiff’s injury is generally one for specialized expert knowledge beyond the ken of the average layperson.” Id. (citation omitted). Ultimately, the causation evidence must rise above mere chance, possibility, or speculation. See id. at 506. As we have explained:A plaintiff must show that the purported violation or deviation is the proximate cause of the injuries sustained. He must prove that the injuries complained of proximately resulted from such want of care or skill. A bare possibility of such result is not sufficient. There can be no recovery where there is no showing to any reasonable degree of medical certainty that the injuries could have been avoided.
