Shunsuke Kosugi, MD*;Shumpei Yoshino, MD;Hiroyuki Oda, MD and Hiroshi Imura, M.D., Iizuka Hospital, Iizuka-city, Fukuoka, Japan

Meeting: Hospital Medicine 2017, May 1-4, 2017; Las Vegas, Nev.

Abstract number: 112

Categories: Innovations Abstracts, Patient Safety


Background: Unexpected overnight adverse events are known to correlate with worse outcomes in inpatients.  Unfortunately, the exact occurrence and etiologies of such events have been less known.   

Purpose: The aim of our study was to clarify the occurrence, etiologies of unexpected overnight adverse events and also propose the algorithm so that the catastrophic events could be prevented by prompt action.


 This is a single center, cross-sectional study, conducted at Aso Iizuka hospital, 1000-bed community hospital from September 1st to December 31st, 2014 and April 8th to October 11th, 2015.  All unexpected overnight adverse events on the floor in the study period were reviewed, and the etiologies were categorized as follows;

“A” – “Airway”        Compromised airways

”B” – “Breathing”    Tachy-/bradypnea, hypoxia

“C” – “Circulation”   Hyper-/hypotension, tachy-/bradycardia, low urine output

“D” – “Disablity”      altered mental status

“E” – “Environment” Hyper-/hypothermia

“F” – “Forget”           lack of confirmation of instructions and prescription

“G” – “Glucose”        Hyper-/hypoglycemia

“O” – “Others”          any other event


There were a total 1216 of events during the study period, and “C” was the single most common etiology.

A – 9(0.7%)

B – 76(6.3%)

C – 265(21.8%)

D – 101(8.3%)

E – 87(7.2%)

F – 227(18.7%)

G – 95(7.8%)

O – 356(29.3%)

When the etiology of “C” was reviewed, tachycardia (27.2%) was the most common followed by hypotension.

Tachycardia – 72(27.2%)

Hypotension – 65(24.5%)

Low urine output – 44(16.6%)

Hypertension – 37(14.0%)

Bradycardia – 27(10.2%)

Others – 20(7.5%)

Looking further the etiology of tachycardia, atrial fibrillation, that is, atrial fibrillation with rapid ventricular rate (RVR) was the most common as shown below.

Atrial fibrillation – 27(37.5%)

Sinus tachycardia – 24(33.3%)

PSVT – 8(11.1%)

VPC run – 5(6.9%)

VT – 4(5.6%)

Atrial flutter – 2(2.8%)

Others – 2(2.8%)

The remarkable point here was the medication selected for atrial fibrillation was quite variable among physicians despite the current international guidelines.  This may represent either unrecognition of current guidelines by physicians or contraindicated condition of patients to use the first line medication. In order to lessen the inappropriate drug selection and subsequently improve inpatients’ outcome, proposing a new algorithm for atrial fibrillation was considered an urgent task.  

Diltiazem continuous infusion – 2(7.4%)

verapamil iv – 12(44.4%)

verapamil po – 1(3.7%)

β-blocker continuous infusion – 1(3.7%)

digitalis iv – 3(11.1%)

Follow up – 6(22.2%)

Elletrocyte adjustment – 1(3.7%)

amiodarone – 0(0.0%)


Atrial fibrillation with RVR was the most common cause of unexpected overnight adverse events in this study.  A variety of drugs were selected for its treatment despite current international guidelines.  Proposing a new algorithm was considered an urgent task to improve inpatients’ outcome.

To cite this abstract:

Kosugi, S; Yoshino, S; Oda, H; Imura, H . UNEXPECTED OVERNIGHT ADVERSE EVENTS IN INPATIENTS: CROSS-SECTIONAL STUDY IN A SINGLE CENTER IN JAPAN. Abstract published at Hospital Medicine 2017, May 1-4, 2017; Las Vegas, Nev. Abstract 112. Journal of Hospital Medicine. 2017; 12 (suppl 2). https://www.shmabstracts.com/abstract/unexpected-overnight-adverse-events-in-inpatients-cross-sectional-study-in-a-single-center-in-japan/. Accessed February 24, 2020.

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