Unanswered Questions

Letter to the Editor Structured Delirium Management in the Hospital—a Randomized Controlled Trial by PD Dr. med. Julia Krämer, Dr. rer. nat. Katharina Nolte, Laura Zupanc, Stefan Schnitker, Dr. med. Anna Roos, Christopher Göpel, Janina Santos Cid, Kirsten Eichler, Thomas van den Hooven, Prof. Dr. rer. nat. Georg Hempel, Prof. Dr. med. Hermann-Joseph Pavenstädt, Dr. rer. nat. Christoph Klaas, Dr. med. Georg Gosheger, Prof. Dr. med. Michael J. Raschke, Prof. Dr. med. Prof. h. c. Heinz Wiendl, and Prof. Dr. med. Thomas Duning in issue 11/2022

Many thanks to the authors for their project „Structured Delirium Management in the Hospital“ (1). The first among the general therapeutic measures is quite rightly continuous administration of fluids, since neurological symptoms can develop when 1% of body fluid is lost and elderly patients often do not drink enough. More than 60% of people older than 70 show signs of dehydration (2).

We asked ourselves how many of the study patients with cognitive deficits were dehydrated? Did the nursing staff responsible for the intervention patients pay attention to regular liquid intake, and might this be the reason for the improved MoCA test at discharge? And, finally: how many patients with delirium underwent surgery, since prolonged preoperative liquid fasting can cause postoperative delirium (3).

Since the guideline recommendation of a two-hour liquid fasting before induction of anesthesia is organizationally hardly implementable, many patients last drink on the evening before their operation. But the longer the liquid fasting times, the higher the incidence of postoperative complications. Could the preoperative liquid fasting time, which was better organized by the study nurses and thus shorter, be the reason for the lower incidence of delirium in the intervention group?

No study showed an association between drinking clear liquids and increased risk of aspiration. And since the half-life of gastric emptying for clear liquids is 10–20 minutes, some hospitals have started to allow their patients to drink clear liquids until they are called to the operating room (4). This extremely simple measure significantly improves patient’s wellbeing and reduces perioperative morbidity.

If further analysis of the study data would show an association between delirium and long preoperative liquid withdrawal times would it not be time to reconsider the guideline recommendation of the two hour preoperative liquid fasting period?

DOI: 10.3238/arztebl.m2022.0241

Dr. med. Anne Rüggeberg

Dr. med. Eike Nickel

Klinik für Anästhesie und Schmerztherapie

Helios Klinikum Emil von Behring

Berlin

References

1. Krämer J, Nolte K, Zupanc L, et al.: Structured delirium management in the hospital—a randomized controlled trial. Dtsch Arztebl Int 2022; 119: 188–94

2. Stookey JD, Pieper CF, Cohen HJ: Is the prevalence of dehydration among community-dwelling older adults really low? Informing current debate over the fluid recommendation for adults aged 70+years. Public Health Nutr 2005; 8: 1275–85

3. Radtke FM, Franck M, MacGuill M, et al.: Duration of fluid fasting and choice of analgesic are modifiable factors for early postoperative delirium: Eur J Anaesthesiol 2010; 27: 411–6

4. Rüggeberg A, Dubois P, Böcker U, Gerlach H: Präoperative Flüssigkeitskarenz: Etablierung eines liberalen Flüssigkeitsregimes mittels Nüchternheitskarten. Anaesthesist 2021; 70: 469–75