Experts described safety-focused innovations in practice and emerging safety issues at a one-day symposium sponsored by B Braun Medical. Topics included fluid therapy, blood glucose control, biosimilars and drug error reduction software
Christine Clark PhD FRPharmS FCPP (Hon)
Prescribing of IV fluids is often poor because the task is given to junior doctors who are not well trained and do not know much about the products, according to Rob Shulman (Lead Pharmacist – Critical Care, University College London (UCL) Hospitals NHS Foundation Trust). Unfortunately, fluid treatment is usually an area of weakness for pharmacists too, he added.
Errors in fluid and electrolyte therapy are more likely to occur in emergency departments, acute assessment units (AAUs) and general medical or surgical wards, but less likely to occur in theatres and intensive care areas, according to NICE guidance. Moreover, recording and monitoring of fluid and electrolyte therapy is poor, explained Dr Shulman. The consequences of fluid mismanagement can be serious.
They include hypovolaemia, pulmonary oedema, hyper- and hyponatraemia, peripheral oedema and hyper- and hypokalaemia. Hypovolaemia can result in underperfusion of critical organs resulting in oliguria, tachycardia, metabolic acidosis together with cold extremities and central nervous system symptoms such as confusion or drowsiness. There is a significant cost to “getting it wrong”, said Dr Shulman. Up to 50% of postoperative patients develop complications with IV therapy and require an additional 2.5 days in hospital at a cost of £600. Two-thirds of the patients who develop pulmonary oedema are admitted to intensive care at a cost of £1200 per day, he said.
The National Institute for Health and Care Excellence (NICE) guideline, Intravenous therapy in adults in hospital, published in December 2013, describes up-to-date thinking on this topic. The intravenous fluids available are saline or Hartmann’s solution, glucose and colloids, which are derived from starches or gelatin. Each of these is distributed in a different way in the body. Colloids remain in the intravascular compartment, Hartmann’s solution and saline go into both the intravascular and interstitial compartments and glucose goes into the vascular compartment and also interstitial and intracellular compartments.
Normal saline is isotonic but contains supraphysiological levels of sodium and chloride – 154 mmol/l compared with 135–146 of sodium and 100–106 of chloride in plasma. The high level of chloride can precipitate hyperchloraemic acidosis and the sodium load can cause serious problems. One litre of normal saline delivers 9g of sodium – “equivalent to 38 bags of crisps” – but the daily requirement of sodium (according to the World Health Organization) is 5g. Excess sodium input can result in oedema as the sodium moves into the interstitial space, explained Dr Shulman.
Fluid resuscitation guidelines call for the administration of 130–154mmol sodium in a bolus of 500ml over 15 minutes. Dextrose 4% with sodium chloride 0.18% does not deliver sufficient sodium and the most effective way to give this dose is to use Hartmann’s solution. The usage of Hartmann’s solution in theatres and intensive care has steadily increased at UCL over the past decade, noted Dr Shulman.
The NICE guideline advises against the use of starch-based colloids for fluid resuscitation. They have been associated with renal failure – hydroxyethyl starch (HES) is deposited in the kidneys and can remain there for ten years, he explained.
Routine maintenance requires 25–30ml/kg/day of water, 1mmol/kg/day of sodium, potassium and chloride and 50–100g glucose/day to minimise the risk of starvation ketosis. The most suitable product to deliver this is dextrose 4% with sodium chloride 0.18% with 40mmol/l potassium chloride, said Dr Shulman. However, giving more than 2.5l per day increases the risk of hypernatraemia and the fluid input should be reduced for patients who are elderly, frail, have renal impairment or heart failure.
In conclusion, Dr Shulman said pharmacists should learn more about intravenous fluids and educate other members of the patient care teams. One useful measure would be to use the resource available on the NICE website. Importantly, pharmacists need to rethink the stock of IV fluids that are held in clinical settings with a view to prompting more appropriate usage.
The use of standardised products could help to improve the safe use of parenteral nutrition (PN) in children, according to Judith Cope (Chief Pharmacist, Great Ormond Street Hospital (GOSH) for Children NHS Trust, London)
At GOSH, about 45 children receive PN every day. A survey in 2008 showed that the majority of PN is for neonates, with only small quantities for children. A systematic review in 2008 yielded very little information about the use of standardised products in paediatrics. One problem here is that there are large changes between the ages of 1 and 16 years, noted Ms Cope.
The use of standardised products would allow routine end-product testing and ensure immediate availability of products. It would also decrease the variability in prescribing and compounding practice and allow more effective use of the skilled pharmacy compounding workforce. However, it might be necessary to make additions to the standard products in order to meet the differing needs of a wide range of patients. At GOSH a standard procedure is followed and detailed guidelines are available (see Resources).
In the pharmacy compounding unit, PN solutions are prepared using an automated compounder that provides a complete audit trail. In addition, a number of safety measures have been built into the local procedures, for example a gravimetric device provides in-process checks and the volumes pumped are recorded and compared with the worksheet. As both high and low glucose levels have contributed to significant morbidly and mortality over the years, compounded PN solutions are routinely sampled for glucose before release, explained Ms Cope. No additions are made to PN solutions on wards.
The finished product is labelled with both contents and the dose expressed as amount per kilogram. Some care is needed here because there must be sufficient overage to prime the giving set, she noted.
Once PN is being infused it is important to check the connections regularly as “children break things off, disconnect things and bite things”, explained Ms Cope.
Most junior doctors know little about parenteral nutrition and so prescribing and managing PN is an important role for consultant pharmacists. In addition, the reporting and analysis of mistakes and poor practice is critical for continual process improvement, she concluded.
Decision support in glucose control
The implementation of a computerised decision support to improve the management of stress-induced hyperglycaemia resulted in better control of blood glucose, Helen Beard (Senior Sister, ICU, West Suffolk Hospitals NHS Trust, Bury St Edmunds, UK) told the audience. The system predicts insulin requirements based on nutritional input and then controls the rate of insulin infusion. It aims for a blood glucose level between 4.4 and 8.3 mmol/l. In the past ‘tight’ control, with target levels of 4.00–6.00 mmol/L, was advocated, she noted.
In the past there had been problems using a conventional algorithm for insulin dosing resulting in wide fluctuations in blood glucose levels and inconsistent monitoring of patients, explained Ms Beard. Space Glucose Control (SGC)
(B Braun) was introduced to the critical care area in May 2013 after in-depth training and upgrading of equipment. The agreed protocol provided automated glucose control when a patient’s blood glucose level went above 10mmol/L and aimed for a target level of 6.3mmol/l. The system is not used for management of diabetic ketoacidosis or for patients who are eating and drinking.
A baseline audit of 20 patients showed that there was poor adherence to the treatment protocol for 60% of the time and that only 54% of samples were taken on time. This was the “prompt for action”, said Ms Beard. After the introduction of the SGC system, a review of 87 patients showed that the average time to reach control had fallen from 11 hours to 5 hours, and the time in the target range had increased from 58% to 80%. Hypoglycaemic episodes were reduced to less than 3%.
Most patients required 36 hours on SGC although one had needed 1000 hours, said Ms Beard. Some patients required high rates of insulin administration, for example, 50 units/hour but the majority need 9.5 units/hour. The frequency of blood glucose sampling was increased and this was probably a good thing, said Ms Beard. Some nurses loved it and some hated it, but the main result was much less variability in blood glucose control, she added.
Future developments of the SGC will include a software modification to alter the target level to 7.2 mmol/l with a safe interval of 5.6–8.9mmol/l.
Medication safety officers
A minimum of two patients per year are still killed by over-rapid administration of potassium and in one recent incident a potassium infusion was administered by gravity alone with only a roller-clamp to control the flow rate, David Cousins (Senior Head, Safe Medication Practice and Medical Devices, NHS England) told the audience.
The National Reporting and Learning System (NRLS) for adverse events is the biggest database of its kind in the world. By 2010 more than five million reports had been analysed. The majority involved no harm to patients but all were important, said Dr Cousins. Medication errors are the third most common category; delayed or omitted doses are top of the list followed by ‘wrong dose or strength’. Opioids, antibiotics, warfarin, low molecular weight heparins and insulin are the top five medicines that consistently cause harm, he said. One recent ‘signal of interest’ from the NRLS was the risk of hypothermia for patients receiving continual renal replacement treatment. Two patients have died as result of administration of fluids at room temperature. Other reports concerned the danger of residual anaesthetic drugs in cannulae and IV lines that had not been properly flushed.
NHS England and the Medicines and Healthcare Products Regulatory Agency (MHRA) are working together to improve the quality of reporting, explained Dr Cousins. Some 32% of medication error reports failed to name the drug involved, he said. In future, medication error reporting is to have a higher profile. Each large NHS organisation is to have a Medication Safety Officer (MSO) and a multiprofessional group within the organisation responsible for reviewing reports regularly and taking action to improve medication safety.
He suggested that MSOs should routinely check on how actively reporting was encouraged and the types of incident that were reported. The NRLS already provides benchmarking data feedback on these topics so that MSOs can see how their organisations perform compared with others. One useful new metric that will be reported on the Medicines Optimisation dashboard will be the number of medication incidents reporting harm divided by the total number of medication incidents. This will provide an indication of preventable harms occurring and a surrogate measure of reporting culture, explained Dr Cousins.
In future, he predicted that there would be improved governance of reporting and learning in healthcare provider organisations with a key role for medication and medical device safety officers. In addition, the establishment of a national medication safety network will enable two-way communication and support the activities of medication safety officers.
Over the past ten years, the use of biologics has steadily increased so that they now account for 30% of drug preparations used in oncology and rheumatology. Coupled with the fact that the patents on a number of biologics will expire in the near future and biosimilars will become available, this raises a number of issues, according to Martin Hug (Director of Pharmacy, University Hospital, Freiburg, Germany). Unambiguous prescribing will be an issue – the Association of the British Pharmaceutical Industry (ABPI) recommends that all biological products should be prescribed by brand name to avoid confusion. This is in line with the EU Directive that requires authorities to ensure that all biological products prescribed or supplied should be clearly identified, he added. However, in his own hospital, the electronic prescribing system uses only INNs and so some software modification will be needed, he said.
The introduction of biosimilars raises further potential problems that could occur in an unplanned way due to drug shortages, suggested Dr Hug. If a switch is made (from originator product to biosimilar) and a patient suffers side-effects or treatment failure, then where would responsibility lie? Clearly the consent of the treating physician is needed before a switch can be made. However, tracing and informing all the prescribers may not be a straightforward exercise – for example, at the University Hospital, Freiburg, no fewer than 100 indications for the use of rituximab have been recorded, said Dr Hug.
Technology to minimise errors
Smart pumps with inbuilt drug error reduction systems have been available in the UK since 2004, but the key safety feature is commonly disabled, explained Steve Bailey (Technical Product Manager, Automated Infusion Systems, B Braun Medical UK Ltd). The majority of smart pumps are used in intensive care units but reports of medication errors from general wards are fourfold higher. For this reason, error reduction efforts should be focused on general wards, argued Mr Bailey.
Modern pumps can provide information in real time and it is possible to have a ward ‘dashboard’ displaying information such as the patients/beds that are receiving infusions and how much longer they have to run. It should also be possible to link smart pumps to electronic patient record systems. In this way, the patient, prescription and medication data could be matched and programming data could be sent automatically to the pump, said Mr Bailey. Effective prevention of medication errors depends on implementing a combination of product and organisational measures, he concluded.
Great Ormond Street Hospital for Children Parenteral Nutrition Guidelines. www.gosh.nhs.uk/health-professionals/clinical-guidelines/nutrition-parenteral/
The one-day conference, Changing Practice to Improve Safety, sponsored by B Braun Medical Ltd, took place on 16 October 2014 at the International Conference Centre in Birmingham, UK