Which patient would a nurse be most concerned about needing surgery to be postponed?

The nurse would be most concerned about postponing surgery for a patient taking Ginkgo Biloba and aspirin daily. Ginkgo Biloba is known to have blood-thinning properties, and when combined with aspirin, it can significantly increase the risk of bleeding during and after surgery. Since both substances can affect the coagulation process, the presence of these in the patient's system raises concerns about ensuring hemostasis during surgical procedures. Delaying the surgery would be a prudent choice to minimize the risk of excessive bleeding, which could complicate the surgical outcome and recovery.

The other scenarios do not pose the same level of immediate concern regarding surgical risk. A vegan patient may have nutritional considerations to think about, but this does not inherently delay surgery the way the blood-thinning effects of Ginkgo Biloba and aspirin could. An elderly client taking nutritional drinks might require assessment regarding overall health and recovery, but their condition is not as directly concerning as the bleeding risk presented by the first patient. Lastly, while considerations around a breastfeeding infant are important, surgical delays would be more related to the infant's specific health conditions rather than a direct risk as seen with the anticoagulant effect of the herbal and pharmaceutical combination.