key: cord-0929968-i70sc79u authors: Nakamura, Yoshihiro; Yasuda, Yoshinari; Shibata, Katsuaki; Yamazaki, Michiko; Yamakawa, Taishi title: Importance of the sick day rule: a case of prerenal acute kidney injury after COVID-19 vaccination in a patient with chronic kidney disease date: 2021-10-02 journal: CEN Case Rep DOI: 10.1007/s13730-021-00651-5 sha: 1000f1890fcf64c704693060b3fa8d5d8879da3e doc_id: 929968 cord_uid: i70sc79u nan diagnosed with AKI, uremic encephalopathy, and bradycardia induced by hyperkalemia and carvedilol. Normal saline, 10-mL calcium gluconate 8.5% solution, and 10 U of regular insulin with 25 g of glucose (50 mL of a 50% solution) were administered. Hemodialysis was performed for 3 h on the day of admission and the following day. GCS scores of 14/15 and urine output were obtained, and dialysis was discontinued. Based on the history of loss of appetite, hypotension on admission, and reversible acute kidney injury, prerenal AKI was diagnosed. Three weeks after admission, her serum creatine level and body weight were 1.15 mg/dL and 42.4 kg, respectively. At discharge, she was prescribed amlodipine (2.5 mg/day), furosemide (20 mg/day), rosuvastatin (2.5 mg/ day), lansoprazole (15 mg/day), and aspirin (100 mg/day). The strong temporal association with vaccination suggests that the loss of appetite was due to vaccination, which led to prerenal AKI and hyperkalemia. Currently, more individuals are being inoculated with COVID-19 vaccine. The reported side effects of the BNT162b2 mRNA COVID-19 vaccine include fever (21.9%), nausea (15.9%), and decreased appetite (5.7%) [2] . Nephrologists often encounter AKI because of acute illness in CKD patients treated with RASi. The "sick day rule" was proposed in patients at risk of AKI [3] . Although evidence is weak, CKD patients are recommended to be checked on regular visits, to temporarily discontinue RASi, diuretics, nonsteroidal anti-inflammatory drugs, and metformin when they experience acute symptoms (e.g., vomiting, diarrhea, and fever) [4, 5] . Therefore, CKD patients on RASi or diuretics may be better advised before COVID-19 vaccination to temporarily discontinue such drugs and consult a hospital when they experience acute illness. Further studies are needed to clarify when RASi or diuretic drugs should be discontinued after COVID-19 vaccination. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. COVID-19 vaccines, and kidney disease Side effects of BNT162b2 mRNA COVID-19 vaccine: a randomized, cross-sectional study with detailed self-reported symptoms from healthcare workers Sick day guidance in patients at risk of acute kidney injury: a position statement from the Think Kidneys Board A practical guide to diagnosis and assessment of chronic kidney disease for the non-nephrologist education Understanding the implementation of "sick day guidance" to prevent acute kidney injury across a primary care setting in England: a qualitative evaluation Acknowledgements We extend our sincere gratitude to Dr. Nozomi Mori for providing constructive comments and warm encouragement. Conflict of interest All the authors have declared no competing interest.Ethics approval This article does not contain any studies with human participants or animals performed by any of the authors.Informed consent Written informed consent was obtained from the patient.