Diurnal variation in the performance of rapid response systems: the role of critical care services—a review article

Abstract

The type of medical review before an adverse event influences patient outcome. Delays in the up-transfer of patients requiring intensive care are associated with higher mortality rates. Timely detection and response to a deteriorating patient constitute an important function of the rapid response system (RRS). The activation of the RRS for at-risk patients constitutes the system’s afferent limb. Afferent limb failure (ALF), an important performance measure of rapid response systems, constitutes a failure to activate a rapid response team (RRT) despite criteria for calling an RRT.There are diurnal variations in hospital staffing levels, the performance of rapid response systems and patient outcomes. Fewer ward-based nursing staff at night may contribute to ALF. The diurnal variability in RRS activity is greater in unmonitored units than it is in monitored units for events that should result in a call for an RRT. RRT events include a significant abnormality in either the pulse rate, blood pressure, conscious state or respiratory rate. There is also diurnal variation in RRT summoning rates, with most activations occurring during the day. The reasons for this variation are mostly speculative, but the failure of the afferent limb of RRT activation, particularly at night, may be a factor.The term “circadian variation/rhythm” applies to physiological variations over a 24-h cycle. In contrast, diurnal variation applies more accurately to extrinsic systems. Circadian rhythm has been demonstrated in a multitude of bodily functions and disease states.For example, there is an association between disrupted circadian rhythms and abnormal vital parameters such as anomalous blood pressure, irregular pulse rate, aberrant endothelial function, myocardial infarction, stroke, sleep-disordered breathing and its long-term consequences of hypertension, heart failure and cognitive impairment. Therefore, diurnal variation in patient outcomes may be extrinsic, and more easily modifiable, or related to the circadian variation inherent in human physiology. Importantly, diurnal variations in the implementation and performance of the RRS, as gauged by ALF, the RRT response to clinical deterioration and any variations in quality and quantity of patient monitoring have not been fully explored across a diverse group of hospitals.Electronic supplementary materialThe online version of this article (doi:10.1186/s40560-016-0136-5) contains supplementary material, which is available to authorized users.

Implementation of a critical care outreach service: a qualitative study

“…The hospital where the CCOS was implemented faced a significant nursing staff shortage and staff shortages have been reported in the literature as an important factor in the failure to identify deteriorating patients (Sundararajan et al. ).…”

“…Yet, the CCOS also engendered conflict and leads to healthcare professionals avoiding responsibility for patient care. The hospital where the CCOS was implemented faced a significant nursing staff shortage and staff shortages have been reported in the literature as an important factor in the failure to identify deteriorating patients (Sundararajan et al 2016).…”

“…It is not surprising then that nurse-physician conflict arose in our study. Others have noted that challenges to nurse-physician hierarchies have contributed to failures of CCOSs (Sundararajan et al 2016). Strong hospital leadership by administrators, nurses and physicians is key to optimal nurse-nurse and nurse-physician working relationships, particularly when implementing new ways of working (Johansson et al 2014).…”

Association Between Survival and Time of Day for Rapid Response Team Calls in a National Registry

“…These discrepancies have been associated with treatment delays and worse outcomes at night for many conditions including maternal outcomes after childbirth (1), stroke (2), myocardial infarction (3), and in-hospital cardiac arrest (4,5). Of note, the disparity in outcome by time of day is most pronounced in lower acuity settings such as unmonitored units, as opposed to intensive care units (ICUs), which are more likely to maintain higher levels of support at all hours (6). …”

Physical deterioration in an acute mental health unit: A quantitative retrospective analysis of medical emergencies

“…Variations in the bodies’ circadian rhythm were postulated as the cause of fluctuations in vital signs, with disrupted sleep–wake cycles linked to changes in physiological parameters and abnormal vital parameters (Sundararajan et al . ).…”