Building a 24-hour roster with five nurses: when the constraint makes it impossible
A 30-bed medical ward has 20 patients. The local staffing standard used in this hospital is a minimum of one nurse for every 6 patients on the day shift (8 am–8 pm) and one nurse for every 10 patients on the night shift (8 pm–8 am), rounded up. The roster for the next 24 hours must be made from five staff nurses: A, B, C, D and E. Constraints: each nurse can work only one 8-hour shift; A has a documented medical condition and cannot work nights; B is on approved leave for the first 8 hours of the day (8 am–4 pm); C can work only the night shift because of an exam; D and E can work any shift. The nurse-in-charge must decide whether the roster is feasible with five nurses and, if not, what to request.
1. Calculate the minimum number of nurses needed on day and night, and test whether five nurses can cover the roster. Show your steps.
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Day: 20 patients ÷ 6 = 3.33, rounded up = 4 nurses. Night: 20 patients ÷ 10 = 2, rounded up = 2 nurses. Total shift-slots needed: 4 + 2 = 6.
Five nurses can each work only one 8-hour shift, so they provide at most 5 shift-slots. That is already one short.
The constraints make it worse. A cannot work night; C can work only night. So the two night slots must be C plus one of B, D or E. If C and, say, B take night, the day shift must be covered by A, D and E - only 3 nurses, not 4. If C and D take night, the day has A, E and B (but B is unavailable until 4 pm), again not 4 from 8 am. There is no arrangement of five nurses that gives four day nurses and two night nurses while respecting A's night restriction, C's night-only restriction and B's morning leave. The roster is not feasible with five.
2. Propose a roster with one additional nurse F who can work any shift, and state any remaining risk.
Read the worked answer
With F added, there are six shift-slots and six nurses, so the arithmetic works. One feasible roster is:
- Day (8 am–8 pm): A, D, E, F - four nurses, meeting the 1:6 ratio.
- Night (8 pm–8 am): B and C - two nurses, meeting the 1:10 ratio.
Check the constraints: A is not on night; B is on leave only until 4 pm and starts at 8 pm, so B is available for night; C works night only; D, E and F work one shift each. No nurse works more than one shift.
The remaining risk is skill mix, not just numbers: C is a staff nurse and B may be less experienced; the night team should have at least one nurse competent in male catheterisation, ECG and emergency drug administration. Also, if a patient deteriorates and needs transfer, the night team of two may be stretched. Record the roster, the ratio calculation and the skill-mix check.
3. If no additional nurse is available, what will you do and what will you document?
Read the worked answer
Escalate immediately to the nursing superintendent or duty administrator, stating the calculated requirement (4 day + 2 night = 6) and the shortfall. Ask for an on-call nurse, a shift overlap, or temporary merging of low-acuity beds with another ward. In the meantime, prioritise by acuity: place the most unstable patients near the nurses' station, reduce non-essential tasks such as routine paperwork, and ensure the night nurse knows whom to call. Do not leave the ward below the safe minimum without a written escalation. Document the patient count, the ratio calculation, the constraints on A, B and C, the request made, the time and the name of the person who received it, and any temporary mitigation. This record protects patients and staff and shows that the shortfall was managed, not ignored.