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Nurse staffing in intensive care is typically based on the number of nurses per patient (nurse to patient ratio), with more nurses needed to care for the most unwell patients. New research showed that many other factors influence how nurse staffing is organised. The mix of nurses’ skills and experience, the layout of the ward, and the availability of other professionals in the team, all had an impact. The potential impact on patient safety and nurses’ wellbeing was considered.

The study was set up to explore how closely nurse to patient ratios are followed in intensive care units, and whether this is the best way to organise nurse staffing.

The researchers found that nurse to patient ratios were seen as a recommendation rather than a rule. Nurse staffing changed throughout the day to respond to patient and staff needs. Teams of different professions (including doctors, and physiotherapists) worked together to respond to situations as they arose.

Future decisions about nurse staffing should consider factors other than nurse to patient ratios, the study concludes.

What’s the issue?

A survey conducted before the COVID-19 pandemic found that more than half (60%) the intensive care units in the UK did not have enough staff. Some 2 in 5 (40%) were closing beds at least once a week because of staff shortages, particularly of nurses. A lack of nurses in intensive care has been linked with worse patient outcomes, including higher rates of infection and death.

In the UK, nurse staffing levels assume that sicker patients need more nurses to care for them than less sick patients. However, it is unclear if this is the best way to manage nurse staffing in intensive care.  

A shortage of nurses and the addition of new support roles in intensive care (including critical care nursing associates) made it timely to consider new ways to organise staff nursing.

This study examined the factors that influence nurse staffing in intensive care. The research was part of the larger SEISMIC study, which is evaluating the impact of nurse staffing models in intensive care.

What’s new?

This study included 52 clinicians (nurses, doctors and nursing assistants) from 8 intensive care units in 4 hospitals across England. Clinicians took part in focus groups about nurse staffing before the pandemic. In addition, researchers interviewed 14 decision makers and policy makers.

The researchers identified 3 themes that influenced nurse staffing in intensive care.

  1. Workload, skill mix and hospital layouts

The number of nurses per patient was seen as a guideline rather than a strict rule, and it was not always followed. There was concern that the loss of this standard would lead to understaffing.

Hospitals aimed to have nurses with a mix of skill levels on each shift, but holidays and study leave could make this difficult. The overall number and skill level of staff, including non-nursing staff, influenced how nurses were organised. For example, the number of experienced senior doctors has decreased in recent years. This has meant that senior nurses are increasingly relied upon to carry out more complex procedures.

However, support staff such as critical care nursing associates, were thought to improve the running of units.

The size and layout of the ward had an influence. For example, nurses looking after patients in single rooms needed cover each time they left the room; they also could not watch over other patients.  That meant more nurses were needed to manage patients safely.

2. Workarounds

Practical solutions to understaffing were common. For example, physiotherapists watched patients (a role they wouldn’t normally do) while nurses took their break.

The number of nurses per patient changed throughout the day according to patient need and to balance staff workload. In general, staffing levels were driven by the severity of patients’ conditions but families in need of emotional support also had an impact.

Clinicians expressed frustration when non-clinical hospital managers made staffing decisions, moved nurses to different wards, or rigidly stuck to nurse to patient ratios. ‘Intensive care champions’ among non-clinical hospital managers, along with twice-daily meetings to discuss staffing, were helpful.

3. Impact on patients and staff

Decisions on nurse staffing aimed to avoid negative consequences for patients, such as dislodged feeding tubes, pressure sores from being in the same position for too long, and delayed admissions. Other ‘red flags’ indicating understaffing were patients who were sedated (medically induced sleep) for longer than necessary, or delayed rehabilitation if nurses were not available to help physiotherapists.

Understaffing left nurses insufficient time to provide full care, such as brushing patients’ teeth or hair. Nurses could be unable to take breaks or stay hydrated.

Understaffing led to staff leaving and agency staff being hired to take their place. Staff were more likely to stay if their workload was balanced to reduce stress, and if they received support from colleagues during tough shifts. For example, experienced nurses were often moved to support more junior staff.

Why is this important?

Nurse to patient ratios were used as a guideline, but other factors influenced decisions on nurse staffing. The needs of patients and their families, staff wellbeing, the ward layout, and the experience of other members of the multi-professional team, all had an impact. Nurse staffing was revised throughout the day to respond to staff and patient needs.

Staffing guidelines assume that clinicians have fixed roles. Any change to nurse staffing guidance needs to consider how different professions work together in intensive care, sometimes outside of their traditional roles.

The researchers say senior nurses need to have the freedom to make decisions about nurse staffing in response to the needs of the ward. In addition, they believe there needs to be a shift away from fixed nurse to patient ratios and less intervention from non-clinical staff.

What’s next?

This study could inform the budgeting and management of staffing in intensive care. The study found that understaffing was common in intensive care in 2021. This is unlikely to have improved since the pandemic.

One study carried out more recently (after the pandemic) found that almost half of intensive care nurses across 9 hospitals met the criteria for post-traumatic stress disorder (an anxiety disorder caused by very stressful or frightening events) and/or depression. Staff wellbeing must be considered in any update to nurse staffing guidelines.

Following the pandemic, new models of nurse staffing are being trialled, for example using teams of registered and non-registered staff to manage a larger group of patients. Future studies could investigate the successfulness of these new models and attempt to figure out which model is best.

You may be interested to read

This Alert is based on: Endacott R, and others. The organisation of nurse staffing in intensive care units: A qualitative study. Journal of Nursing Management 2022; 30:1283–1294.

A systematic review of the effects of nurse staffing on patient, family and hospital outcomes: Rae PJL, and others. Outcomes sensitive to critical care nurse staffing levels: A systematic review. Intensive and Critical Care Nursing 2021;67:103110.

The Intensive Care National Audit and Research Centre (ICNARC) website who aim to facilitate improvements in the structure of critical care.

NHS resources on safer staffing processes for nurses and midwives.

Read our Evidence Collection on Staffing on Wards: Making decisions about healthcare staffing

Funding: The research was funded by the NIHR Programme Development Grant.

Conflicts of Interest: The study authors declare no conflicts of interest.

Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.


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