Preoperative Fasting: Old Habits Die Hard

Abstract

Prolonged preoperative fasting is a time-honored tradition. The typical order of "npo after midnight" (or no liquid or food after 12 am on the day of surgery) has been challenged in recent years-so much so that in 1999 the American Society of Anesthesiology (ASA) revised its practice guidelines for preoperative fasting in healthy patients undergoing elective procedures. The newer, more liberal recommendations, based on studies showing that pulmonary aspiration occurs only rarely as a complication of modern anesthesia, allow the consumption of clear liquids up to two hours before elective surgery, a light breakfast (tea and toast, for example) six hours before the procedure, and a heavier meal eight hours beforehand. There is a well-known lag between the dissemination and implementation of practice guidelines, so the authors sought to determine whether the publication of the revised ASA recommendations had changed preoperative fasting practices. They interviewed 155 patients in one hospital about their preoperative fasting, comparing instructed, actual, and ASA-recommended fasting durations for liquids and solids. Their findings demonstrate that the majority of patients continued to receive instructions of npo after midnight for both liquids and solids, whether they were scheduled for early or late surgery. On average, the patients fasted from liquids and solids for 12 and 14 hours, respectively, with some patients fasting as long as 20 hours from liquids and 37 hours from solids. These fasts were significantly longer than those recommended by the ASA, indicating that inappropriate preoperative fasting is an issue that demands attention. The authors conclude that more collaboration between nurses and physicians is needed to assure that fasting instructions are consistent with the ASA guidelines and that patients understand these directives.

Präoperative Nüchternzeiten

“…Wie verschiedene Studien belegen, entsprechen die tatsächlichen präoperativen Nüchternzeiten oft in keiner Weise den Empfehlungen der meisten anästhesiolo-gischen Gesellschaften [5,6,12]. Gründe dafür sind möglicherweise eine gewisse Trägheit, von der traditionellen Praxis abzuweichen, der Glaube, dass trotz aller wissenschaftlichen Erkenntnisse län-gere Nüchternzeiten sicherer seien, über-triebene Sorge um eine Aspiration und die Angst vor juristischen Konsequenzen [5].…”

“…Gründe dafür sind möglicherweise eine gewisse Trägheit, von der traditionellen Praxis abzuweichen, der Glaube, dass trotz aller wissenschaftlichen Erkenntnisse län-gere Nüchternzeiten sicherer seien, über-triebene Sorge um eine Aspiration und die Angst vor juristischen Konsequenzen [5]. Bereits in den 1980er-Jahren konnte gezeigt werden, dass gelockerte Karenzvorschriften für klare Flüssigkeiten sogar in einer signifikanten Verminderung des im Magen verbleibenden Volumens resultierten [20,37] und außerdem auch vergleichbare pH-Werte erzielt werden konnten [20].…”

“…Obschon wissenschaftliche Grundlagen belegen, dass die liberalisierte Nüch-ternheitsregelung sicher angewendet werden kann, zeigen mehrere Publikationen, dass die tatsächlichen Nüchtern-zeiten in der Praxis weiterhin die empfohlenen Mindestzeiten überschreiten [4,5]. So konnten beispielsweise Pearse u. Rajakulendran durchschnittliche präoperative Nüchternzeiten von 12 h und 30 min für Flüssigkeiten bzw.…”

Preoperative chewing gum and foreign body airway obstruction

“…While most anesthesiologists, in accordance with American Society of Anesthesiologists (ASA) guidelines, are modifying To the editor: In the past decade, NPO (nil per os) rules for scheduled surgical operations have been under contestation [1]. However, the most recent NPO guidelines do not refer to chewing-gum consumption [2].…”

“…The original endotracheal tube after extubation, with the attached mass of gum, leaving the cuff intact. Due to its location, the foreign body was not forced into the tracheobronchial tract their NPO rules [1,2], none of the new guidelines reports the intake of solids. Digestion of apparently innocent solid substances such as chewing gum constitutes a potential risk during anesthesia [4].…”