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Monitoring plasma sodium levels in babies | Signal

Reference number
Issue date25 March 2011

This Signal is about the investigation into the death of a baby at the Neonatal Intensive Care Unit, Nottingham University Hospitals NHS Trust.

In 2009 a baby was prescribed sodium infusion to correct hyponatraemia, partly attributed to the use of diuretic drugs over the previous week, during which time the falling plasma sodium level was not recognised. The required amount of sodium was correctly calculated. An infusion to provide this amount over a 24 hour period was prescribed legibly (0.5mmol/ml) and consistent with hospital practice. The infusion prepared was of undiluted concentrated 30 per cent sodium chloride (i.e. 5 mmol/ ml).  The baby sustained irreversible brain damage and died three days later.

Trust policy describes that two nurses share responsibility for interpreting the prescription, drawing up the correct elements and checking each other’s actions. The nurses had received appropriate training. 
The underlying causes for this incident were:

• a breakdown in understanding as to the correct constituents of the infusion syringe despite evidence of verbal instruction and discussion between team members;

• the nursing handover process failed to identify that the syringe infusion syringe label was not consistent with the prescription.

Actions taken by the Trust following the incident:

1. Protocols were strengthened for monitoring and managing plasma sodium levels in babies receiving diuretics and saline infusions.

2. The infusion prescription chart was redesigned to distance the diluent and additive columns.

3. Ampules of concentrated sodium chloride solutions (30 per cent) are recorded, ordered, stored and administered as if a controlled drug.

4. Low volume infusions to correct hyponatraemia are not prepared using 30 per cent saline, but using ready-prepared 1.8 per cent sodium chloride.

5. Prescription documentation and labelling of all infusion fluids are checked at each nursing handover.

6. Working practices were changed to prohibit interruption of ‘cot side’ preparation of infusions and to protect the ‘supernumerary’ role of the nurse in charge.  

Please contact the Trust at safety@nuh.nhs.uk with any initiatives to reduce risk in these areas.

This Signal emerged from a local investigation carried out by the Trust and at their request is being shared by the NPSA for wider national learning.