PREOPERATIVE FASTING patient may be uncomfortable evaluated evidence and expert After reading “Preoperative while fasting after midnight. Gas consensus. Adhering to them may Fasting: Will the Evidence Ever tric emptying times may be short reduce clinical variation from the Be Put into Practice?” (October in normal patients, but many con best available evidence, improve 2011), I’d like to point out an ditions may delay such emptying. quality of care, and reduce mal other reason for ending the stan For patients who must wait until practice liability.3 dard practice of npo (non per os, the afternoon for their surgery, Although certain conditions or nothing by mouth) after mid an iv infusion may be started. may delay gastric emptying of night before surgery, and this is Patients scheduled for surgery solids (obesity, diabetes with gas based on personal experience. later in the day may have a light troparesis, use of narcotics), there I followed the preoperative in breakfast. are no data suggesting that pa structions prior to a mastectomy. The American Society of Anes tients with these conditions are Usually my veins offer easy ac thesiologists (ASA) recommen at greater risk for pulmonary aspi cess when inserting an iv. Unfor dations on the issue of fasting ration when clear liquids are con tunately, on the morning of my before surgery, which are not la sumed up to two hours before surgery, I was stuck five times in beled standards, are interesting surgery. In fact, patients who con an effort to get an iv going. The but don’t necessarily represent sume clear liquids up to two to preoperative nurse gave up after the standard of care. Also, to four hours prior to surgery have three tries; the anesthesiologist, my knowledge, wellconducted been found to have lower gastric on his second try, finally got one randomized, doubleblind studies volumes and similar or higher pH started in a vein in my foot. Dur haven’t been undertaken to eval values compared with healthy pa ing this process, the anesthesiol uate the incidence of aspiration in tients who fast more than four ogist casually mentioned that patients who followed npoafter hours.4–9 there was evidence to support the midnight instructions versus those What puzzles me is why we’re notion that patients can consume who were allowed to eat and still debating preoperative fasting clear liquids within a shorter time drink near the time of surgery. and the consumption of clear liq span before surgery. Finally, I have doubts about uids. In addition to recommen How many other patients have the author’s statement that it’s a ding clear liquids until a few hours been stuck numerous times before myth that clear liquids ingested before surgery, international prac surgery, simply because they’re up to two hours before surgery tice guidelines recommend the dehydrated? It’s painful, and it’s increase the risk of aspiration. routine use of oral carbohydrate a waste of time for staff to start Why bet a patient’s life on it? rich clear beverages two to three an iv on a scheduled surgery pa Mitchel B. Sosis, MD, PhD hours before surgery in most pa tient who’s dehydrated due to Lafayette Hill, PA tients.10, 11 Referred to as carbohy preoperative instructions. drate loading, this can reduce the Mary Lynn Mathre, RN Author Jeannette T. Crenshaw patient’s discomfort, including Howardsville, VA responds: Based on expert opinion preoperative thirst and anxiety and the results of multiple studies and postoperative nausea and I read with interest the recent ar (including randomized controlled vomiting. It also reduces several ticle on preoperative fasting for trials and metaanalyses of these), of the potentially dangerous re patients undergoing surgery with the ASA recommended a mini sults of preoperative fasting, such anesthesia. As a practicing anes mum fast of two hours from clear as postoperative insulin resistance thesiologist, this is a topic of great liquids for healthy patients of all and diminished immune response. concern. I was surprised the au ages receiving general, regional, thor didn’t explicitly mention that or monitored anesthesia care for The reference list for this letter can pulmonary aspiration can be fa elective procedures.1, 2 The ASA be found at http://links.lww.com/ tal, even when the aspirated ma specified when the guidelines may AJN/A31. t terial is only a liquid of high need to be modified or may not acidity. apply. Although practice guidelines For more letters from AJN Accordingly, an anesthesiolo may not represent local standards readers, go to http://links. gist’s first duty is to prevent this of care, they are strong recom lww.com/AJN/A32. dreaded complication, even if the mendations based on carefully
12 AJN ▼ January 2012 ▼ Vol. 112, No. 1 ajnonline.com