Schon zu Beginn der Anästhesie 1846 wurde darauf hingewiesen, dass ein mehrstündiges
präoperatives Nüchternheitsgebot bestehende Erschöpfungszustände verschlimmert. Dennoch
hat sich in den folgenden Jahrzehnten „Nihil per os nach Mitternacht“ etabliert. Unter
der Annahme, dass ein nüchterner Patient einen leeren Magen hat und somit nicht aspirieren
kann, lag der Fokus auf: Hauptsache nüchtern, egal wie lange. Heute sieht man das
differenzierter.
Abstract
When anaesthesia was in its infancy, the purpose of preoperative fasting was to prevent
nausea and vomiting. In these early days of anaesthesia, liquid fasting periods were
kept short to avoid exhaustion. The later introduction of the ‘nothing by mouth after
midnight’ rule aimed to prevent aspiration. For decades, no distinction was made between
clear liquids and solids. However, as studies could not demonstrate a difference in
gastric residual volume when consuming clear liquids within the last 2–4 hours versus
fasting for over 4 hours, the guideline recommendation regarding clear liquids was
reduced to 2 hours by the end of the last century. As solid food remains in the stomach
for longer, fasting periods of 6–8 hours are required. These should be adapted according
to the type of food and the characteristics of the patient. However, periods of liquid
fasting often exceed the recommended 2 hours, with a median duration of 9–12 hours.
This can lead to dehydration, insulin
resistance, and postoperative complications. As clear liquids leave the stomach quickly,
an international, multidisciplinary consensus statement recommends implementing institutional
protocols to minimise preoperative fasting times for liquids. These protocols can
either encourage patients to drink clear liquids up to 2 hours before anaesthesia
is induced or allow for liberal liquid fasting times.
Schlüsselwörter
präoperative Nüchternheit - Aspiration - klare Flüssigkeiten - Nüchternheit
Keywords
preoperative fasting - aspiration - clear liquids - fasting
