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A fundamental conflict of care: Nurses’ accounts of balancing patients' sleep with taking vital sign observations at night

Aims and objectives To explore why adherence to vital sign observations scheduled by an early warning score protocol reduces at night. Background Regular vital sign observations can reduce avoidable deterioration in hospital. early warning score protocols set the frequency of these observations by the severity of a patient's condition. Vital sign observations are taken less frequently at night, even with an early warning score in place, but no literature has explored why. Design A qualitative interpretative design informed this study. Methods Seventeen semi‐structured interviews with nursing staff working on wards with varying levels of adherence to scheduled vital sign observations. A thematic analysis approach was used. Results At night, nursing teams found it difficult to balance the competing care goals of supporting sleep with taking vital sign observations. The night‐time frequency of these observations was determined by clinical judgement, ward‐level expectations of observation timing and the risk of disturbing other patients. Patients with COPD or dementia could be under‐monitored, while patients nearing the end of life could be over‐monitored. Conclusion In this study, we found an early warning score algorithm focused on deterioration prevention did not account for long‐term management or palliative care trajectories. Nurses were therefore less inclined to wake such patients to take vital sign observations at night. However, the perception of widespread exceptions and lack of evidence regarding optimum frequency risks delegitimising the early warning score approach. This may pose a risk to patient safety, particularly patients with dementia or chronic conditions. Relevance to clinical practice Nurses should document exceptions and discuss these with the wider team. Hospitals should monitor why vital sign observations are missed at night, identify which groups are under‐monitored and provide guidance on prioritising competing expectations. early warning score protocols should take account of different care trajectories.


| INTRODUCTION
Monitoring vital sign is the first step in the "chain of prevention" of serious events like death or cardiac arrest (Smith, 2010), but reasons for a lack of adherence to monitoring protocols are the least studied (Odell, 2015). Inadequate responses to deterioration were the most common cause of critical incidents reported to a UK national database (Donaldson, Panesar, & Darzi, 2014). However, routine vital sign observations are less frequently carried out at night (National Patient Safety Agency (NPSA) 2007). Even under a standardised nursing protocol linking frequency of vital sign observations to patient severity of illness (acuity), vital sign observations remain lower at night than during the day (Hands et al., 2013;National Patient Safety Agency, 2007).

| BACKGROUND
Controlling body temperature, managing breathing, supporting sleep and keeping patients safe are all part of the fundamental care work of nurses (Kitson, Conroy, Wengstrom, Profetto-McGrath, & Robertson-Malt, 2010). Yet monitoring vital sign at night is likely to disrupt sleep, setting up a potential conflict of care priorities. There is great variation internationally in the minimum frequency of observations and the content of routine vital sign sets (see Smith, Recio-Saucedo, & Griffiths, 2017 for a more detailed discussion), although a greater frequency of vital sign observations is associated with a reduction in unexpected deaths and intensive care admissions (Mitchell et al., 2010).
Vital sign observations at night have traditionally been managed in different ways internationally, but current approaches are converging.
In the USA, where four-hourly vital sign observations throughout the night have been the norm, researchers have argued that a system based on the level of patient acuity allows a proportionate response, balancing risk with the need to support rest (Yoder, Yuen, Churpek, Arora, & Edelson, 2013). In the UK, NICE has recommended a graduated monitoring approach with vital sign observations taken at least every 12 hrs in all hospitalised patients, with increasing frequency as patient acuity rises (NICE Clinical Guidelines, 2007). Internationally, there has been a development of early warning score (EWS) algorithms, such as the National early warning score (NEWS) (Royal College of Physicians, 2012) in the UK. early warning scores use the extent of deviation of vital sign measurements from an expected, "normal" range to calculate a score; higher scores require more frequent vital sign observations on a sliding scale. There is evidence that adherence to early warning score-led intervals is associated with reduced mortality (De Meester et al., 2013a;Schmidt et al., 2015) and reduced serious adverse events (De Meester et al., 2013b). However, the optimum period between vital sign observations is not yet established (Smith et al., 2017).
Evidence suggests vital sign observations are taken less frequently at night than during the day, even when an early warning score protocol is used (Hands et al., 2013;National Patient Safety Agency, 2007). Most night-time vital sign observations are taken at the beginning and end of the night shift (Hands et al., 2013;Yoder et al., 2013). Hands et al. (2013) found that although more acutely unwell patients were observed more often during the night, the frequency of vital sign observations was not as often as required by the early warning score protocol. While vital sign observations were performed as scheduled 73% of the time between What does this paper contribute to the wider global clinical community?
• Nursing staff on night shifts experience a conflict between the care tasks of supporting sleep and monitoring patients for deterioration. This may result in covert strategies to support uninterrupted "blocks" of sleep under an early warning score protocol.
• Patients with chronic conditions or dementia may be under-monitored at night while patients requiring palliative care risk being over-monitored under an early warning score protocol.
• A lack of clarity about the optimum frequency of vital sign observations and difficulty in using early warning score algorithms with patients on long-term management or palliative trajectories of care risks delegitimising their use and reducing safety in some patient groups. Somewhat surprisingly, no study has directly explored why vital sign observation sets are performed less frequently at night (Hands et al., 2013;Odell, Victor, & Oliver, 2009). While there is some evidence about why nurses monitor certain vital sign (see Flenady, Dwyer, & Applegarth, 2017) or follow an early warning score protocol, the reasons are not night-time specific (see Odell et al., 2009).
In their systematic review of the evidence, Odell et al. (2009) found nurses use vital sign observations to support clinical "intuition"-potentially using "pattern recognition" of deteriorating patients in their speciality area-and family concerns about the patient's condition.
Other factors identified in the papers included relationships with other health professionals, issues with equipment (difficulties in access, poor maintenance or broken or missing equipment) and the clinical environment.
Despite the paucity of evidence, existing literature suggests areas requiring further examination. We know from Hands et al. (2013) that acuity does moderate frequency of vital sign observations to a certain extent, which may reflect attempts to manage competing priorities in a systematic way (Hands et al., 2013). It is possible the night-time difference relates to attempts to support sleep. However, there is no research evidence exploring how nursing staff navigate these dilemmas in their routine work at night. Qualitative research is needed to explore why vital sign observations reduce at night (Buist & Stevens, 2013).
This study aimed to explore why adherence to early warning score protocol-led observation schedules is poorer at night by analysing nurses' accounts of decision-making about taking vital sign at night.

| Design
This was a qualitative interpretative study based on semi-structured interviews with nurses, exploring decisions surrounding use of a local early warning score protocol at night.

| Setting-the night surveillance study
The study was based in a large English NHS acute district general hospital that has used an early warning score-led monitoring protocol on all adult medical and surgical wards since 2009. This is implemented using mobile devices running VitalPAC TM software (Smith et al., 2006). Vital-PAC TM uses the National early warning score (NEWS

| Interviews
Interviews lasting between 19-61 min were carried out using a semi-structured interview schedule, either face-to-face in a neutral setting (n = 9) or via telephone (n = 8). The interview guide was developed by JH in consultation with the rest of the study team. Memoing was used alongside the interviews to capture interesting topics after each interview, with memos saved in NVivo alongside transcripts.

| Analysis
Qualitative analysis was carried out following the method described by Lofland, Snow, Anderson, and Lofland (2006). This is a constant comparative method informed by grounded theory, but allowing the use of some initial top-down codes related to areas of interest in the project. NVivo software was used for the analysis. Two members of the team (JH and AR-S) coded the data. Both coded three transcripts blind and compared and agreed coding of transcripts and generation of new codes. The remaining transcripts were divided between JH and AR-S for full coding. Codes created and coding of individual transcripts were discussed at regular intervals, with differences recorded in NVivo memos and discussed to reach a consensus. Finally, after coding of all transcripts was completed, each coder checked the other's transcripts, suggesting changes where they did not agree with the coding. Differences of opinion were discussed until final coding was agreed.

| Ethical considerations
The parent study-the Night Surveillance Study-received ethical clearance from the University of Southampton and governance  This meant night-time nursing staff faced a dilemma: how to support sleep while also carrying out vital sign observations. Interviewees described the importance of allowing patients to gain the largest feasible uninterrupted "block" of sleep: . . .It depends on what time we finish the night time stuff. So if we finish at 11, then waking them up at two or three is okay, but if we don't finish until twelve or one then I would be reluctant to wake them up any earlier than four before I did it again, just because I think they just need a solid block of undisturbed sleep. . .

(HCSW/SN2-low adherence ward)
Only one interviewee (on a medium adherence ward) claimed she had never woken someone at night to take vital sign observations (although she said she would if they had interrupted breathing due to sleep apnoea). Another interviewee (based on a medical ward) described how the nurse in charge on one shift asked her not to wake patients to do vital sign observations.
Interviewees reported using different strategies to support the longest "block" of sleep. These did not always meet the requirements of the early warning score protocol. Sometimes, an observation was carried out earlier than required while a patient was still awake, or vital sign observations were taken when someone woke in the night. These strategies adhered to the protocol and allowed patients to sleep for the full interval between vital sign observations. Some nurses described being able to carry out vital sign observations without waking their patients, particularly when patients were connected to automatic monitoring equipment at night. However, this could be undermined by noisy equipment and was particularly difficult when using a blood pressure cuff. Others decided to measure only the vital sign that was scoring highly, rather than the whole set required by the early warning score protocol (which would be recorded as nonadherent).
Avoiding sleep disturbance was also affected by the proximity of other patients, even if the patient requiring vital sign observations was awake: .  Interview data suggest their higher level of adherence may be an artefact of following the postoperative frequencies for vital sign observations recording, which were often more frequent than the intervals required by the early warning score protocol: . . .Whereas because we're slightly different in our surgical management that we would automatically do obs, we've never on [our ward] got to be 'do your once-a-day obs'. We don't do that. We automatically do four-hourly or six-hourly anyway. . .

(RN9-medium adherence ward)
Two of the interviewees on medium adherence wards reported needing to provide a "fresh set of obs" for Doctors coming on shift at 6am. These threatened their ability to protect longer periods of sleep: . Interviewees argued that vital sign observations may be needed less frequently for these patients (once or twice a day to monitor the effectiveness of medication) so did not need to be performed at night.

| DISCUSSION
This study aimed to explore the reasons why vital sign observations monitoring reduced at night, even with an early warning score protocol in place. Ward staff decisions about whether or not to follow the protocol were influenced by their own judgement about the necessity and urgency of the vital sign observations required, ward factors, hospital surveillance targets and patient-specific factors. Most of these factors could be expected to influence observation taking during the day. However, while staff would carry out what they judged to be "unnecessary" vital sign observations during the daytime, the protocol was more likely to be resisted at night as it would mean interrupting patients' sleep. This mirrors some of the findings in Odell et al. (2009), which highlighted the role of nurse clinical judgement, but explains why this may become more pronounced at night.
While most of our interviewees did take vital sign observations at night if they felt they were necessary, some described how they or the nurse in charge had a policy of not taking vital sign observations at night. However, our study also found that unqualified personnel were carrying out observations and sometimes making clinical judgements. This raises concerns about the impact of staff competence on safety (such as adverse events and mortality). More research needs to explore if this is a commonplace practice and how it affects patient safety.
The early warning score reading was used as part of the clinical decision for almost all interviewees as an indicator of acuity rather than required frequency of vital sign observations. This could explain why previous research has found that increased acuity increases adherence to the observation schedule at night, but not to the level expected by the early warning score protocol (Hands et al., 2013).
The impact of ward factors was more complex. Both ward-level protocols and perceived doctor expectation of vital sign observations appeared to override the early warning score protocol. In some cases the frequency of vital sign observations required by postoperative protocols was greater than that required by the early warning score protocol. This could explain some of the high adherence rates among wards using such protocols, suggesting they are an artefact of a different process rather than reflecting adherence to the early warning score protocol. Where a "fresh" set of vital sign observations was However, there is also a risk that a lack of transparent deci- where surgeons and physicians were concerned about the impact of standardised pathways on professional decision-making (Martin, Kocman, Stephens, Peden, & Pearse, 2017). However, rather than rejecting these outright they were able to build more nuanced pathways that actually enhanced clinical decision-making and collaboration between professional groups. The findings above provide a strong steer on how deterioration-based algorithms could be adapted to reflect different care trajectories.

| STUDY LIMITATIONS
This was a small, qualitative study in a single centre study, so it is not possible to generalise. Nonetheless it meets the need for an exploratory qualitative, in-depth study of why vital sign observations are taken less at night, as highlighted by Buist and Stevens (2013).
As these findings chime with existing qualitative and quantitative research, this suggests some of our conceptual findings may be transferable (Lincoln & Guba, 1985) to nursing practice at night more generally.
Although we designed the study as purposive, using a "deviant case" sample, we had to open it to all who were eligible and interested due to difficulties recruiting enough participants. We were still able to interview nurses from the wards with the extremes of monitoring adherence, but also include a useful cross section of staff working on a range of wards with differing levels of adherence to the early warning score protocol. One potential weakness of the sampling approach is the use of whole ward statistics, which cannot Further qualitative work could aim to recruit a more homogenous There were also concerns raised by some interviewees about the difficulties of waking patients with dementia to take vital sign observations, which were more to do with patient or ward management than patient safety. While there is more research to be carried out to establish the optimum frequency of vital sign observations, a key issue is the widespread perception of "exceptions" that are not accounted for by the system. These raise two potential safety issues. These findings also highlight the importance of taking into account the wider context within which nursing practices occur (Hands et al., 2013). As with all nursing staff, our interviewees' working practices were bounded by ward-and hospital-level protocols, targets and monitoring, and the expectations of medical staff.
These served to threaten their ability to protect uninterrupted chunks of sleep, to follow early warning score-led intervals and to HOPE ET AL. It is important to identify certain patient groups whose care trajectories do not fit neatly into the prevention of deterioration model that prescribes the use of an early warning score protocol.
Where The evidence base relating to early warning score protocolsparticularly the optimum frequency of observation sets-is still developing. Individual interpretations, intervals and uses vary between hospitals at national and international levels. Despite these limitations, the majority of our interviewees found having an early warning score calculated by a digital device with reminders to be a useful addition to practice. However, rather than simply following the protocols they instead used them much like a Satellite Navigation System-guiding but not dictating their work. Therefore, for nurses currently using such protocols, we recommend the involvement of wider teams in decision-making and creating auditable documentation for these decisions. For hospitals implementing early warning score protocols, we suggest the use of an exceptions reporting system that can monitor and highlight exceptions, allowing for the identification of systematic over-or under-monitoring of specific patient groups, particularly at night.

ACKNOWLEDG MENTS
We thank the other members of the Night Surveillance Study team for their valuable contributions and insights: Dr Paul Meredith (Portsmouth Hospitals NHS Trust), Nicky Sayer (Portsmouth Hospitals NHS Trust), Yvonne Alton (Patient and Public Involvement [PPI] advisor-independent) and Anya de Iongh (PPI advisor-independent) and Dr Antonello Maruotti (University of Southampton).
We also wish to thank the anonymous reviewers for their constructive feedback. Finally, we wish to thank the nursing staff members who were generous enough to share their time and experiences with us.

CONTRI BUTIONS
The authors have confirmed that all authors meet all three of the ICMJE criteria for authorship credit (www.icmje.org/ethical_1au thor.html), as follows: (1)