Epidural infusions can be a safe and effective technique for providing perioperative analgesia. However, they are not without risk. This article describes how a number of changes in practice, including new documentation, were used as risk reduction strategies to make epidural analgesia as safe as possible.
- This article has been double-blind peer reviewed
- Figures and tables can be seen in the attached print-friendly PDF file of the complete article found under “related files”
Felicia J. Cox, MSc, RN, is senior nurse, pain management, Royal Brompton and Harefield NHS Trust, Middlesex; Kirsty Scott, MRPharmS, Dip Clin Pharm, IP, is lead directorate pharmacist, critical care and A&E, West Hertfordshire Hospitals NHS Trust.
Cox, F.J., Scott, K. (2008) Improving epidural safety through new documentation. This is an extended version of the article published in Nursing Times; 104: 12, 26-27.
A National Patient Safety Agency epidural alert revealed that, between 2000 and 2004, there were three patient deaths associated with the inadvertent administration of epidural bupivacaine infusions by the intravenous route (NPSA, 2007). Epidural analgesia is not without risk. Potential serious consequences include mechanical trauma (Nolte et al, 2007); local anaesthetic toxicity (Koczmara et al, 2007); epidural haematoma (Horlocker, 2004); and abscess formation (Cox, 2002).
Bupivacaine is a long-acting amide local anaesthetic that is commonly used for nerve blocks and regional analgesic techniques, for example, epidural analgesia. When given intravenously, bupivacaine may cause adverse changes to cardiac rhythm and contractility (Zimmer et al, 2007). These changes may be profound and patients may require extended cardiopulmonary resuscitation (CPR) and the institution of cardiopulmonary bypass. Studies in animal models have shown that intravenous lipid emulsion (such as Intralipid used for parenteral nutrition) can reverse local anaesthetic-induced asystole, but the optimal dose and safety have not been established in humans (Corman and Skledar, 2007).
Dysrhythmias may be only a warning sign of inadvertent IV administration (Ohmura et al, 1999). Although newer local anaesthetics such as ropivacaine (a pure S-enantiomer) and levobupivacaine (a single isomer of bupivacaine) are less toxic than bupivacaine, they must be regarded as ‘safer’ rather than ‘safe’ (Veering, 2003).
Numerous publications have tried to raise the profile of medication safety and encourage manufacturers, pharmacies, prescribers and those who administer analgesic medicines to try to reduce the risk of medication-related adverse events. In most hospitals, the responsibility of medication safety would lie with the acute pain service.
This article describes how a pain management nurse and a specialist pharmacist developed and implemented an epidural prescription chart, streamlined available infusions and optimised storage to minimise the risks associated with epidural analgesia. These changes were all undertaken in addition to an ongoing education programme for all staff involved with epidural analgesia.
Identifying the need for change
The practice of providing epidural analgesia has been well established with bupivacaine and ropivacaine at Royal Brompton and Harefield NHS Trust for managing acute pain associated with thoracic surgery. This has expanded to include patients undergoing cardiac surgery. As a result of this growth in service provision, an increasing number of different analgesic combinations were used according to the type of surgery, the block required, the anaesthetist’s preference and individual patient need.
A multidisciplinary medication safety initiative (MSI) group was formed to try to reduce the risk of medication-related adverse events. The MSI group includes the lead clinician for clinical risk, the director of pharmacy, the governance pharmacist and a mix of prescribers and nurses. Every three months, all medication-related adverse events for that period are reviewed and trends explored. As a founding member of the group, the senior nurse for pain management is aware of the possibilities and actively seeks to reduce risks associated with epidural analgesia.
At the time the NPSA published its epidural alert, the trust complied with all the practice recommendations with the exception of epidural storage. The risk reduction strategies used are listed in the box below.
Strategies to reduce risks associated with epidural analgesia
Change to a potentially safer infusate:
- Liaise with industry to supply levobupivacaine in combination with fentanyl rather than bupivacaine
- Use commercially prepared infusates
- Label clearly (judicious use of yellow)
- Limit presentations (see below)
- Use visibly contrasting presentations
- Separate storage for epidurals, away from infusions for other routes (for example, intravenous)
- Epidural infusions containing controlled drugs stored separately from plain local anaesthetic infusion
Initiation of epidural infusion:
- Registered staff only
- Must have attended an education programme
- Competency-based assessment by acute pain service member
- Dedicated infusion device
- Combination of the prescription, troubleshooting guide and nursing record of observations
- Colourful and immediately recognisable
- Easy to complete
Local policy clearly states that professionals administering medicines by any route should check the five ‘R’s’ or ‘rights’ to ensure safe medicine administration. These are:
- The right patient;
- The right medicine;
- The right dose/amount;
- The right route (intravenous, epidural, intrathecal etc);
- The right frequency.
Failure to adhere to these basic principles introduces risk. Although single-nurse administration (for example, of oral medicines) is said to make individuals take more responsibility for their actions and reduce the risk of errors, there is scant evidence that this is safer in high-risk patient groups or routes (for example, by the epidural route or in paediatric patients).
Minimising confusion by limiting presentations
To minimise confusion related to the variety of concentrations and different combinations of local anaesthetics and opioids, standard minibags were introduced to replace the 50ml syringes of epidural infusates prepared in the ward by nurses. The local drugs and therapeutics committee supported the minibag introduction as they agreed that this new presentation, although more expensive, would:
- Minimise the risk of drug dilution errors as the medicine was commercially prepared and pre-diluted;
- Reduce the risk of contamination, as the frequency of breaking the administration set circuit (giving set, filter, epidural catheter) to change the infusate was decreased by the larger infusate volume.
When epidural minibags were introduced, the only low-dose local anaesthetics commercially available were plain bupivacaine 0.1% or ropivacaine 0.2% (100ml) and an opioid-containing combination (bupivacaine 0.1% + fentanyl 2mcg/ml 250ml). Although fentanyl is unlicensed for administration into the epidural space it is a commonly administered epidural opioid. Unlicensed preparations such as the combination of bupivacaine and fentanyl for epidural use are known as ‘specials’ and are manufactured by industry and a small number of licensed hospital pharmacies.
Since the introduction of the potentially safer local anaesthetic levobupivacaine and following problems with the supply of bags of ropivacaine, the pain management service has revised the types of epidural infusions that are available.
Levobupivacaine is now the sole available local anaesthetic for epidural infusion that is supplied by the pharmacy. It is supplied in a pre-diluted form; as either plain levobupivacaine 0.125% or levobupivacaine 0.125% in combination with fentanyl 4mcg/ml. The 200ml plain minibag is supplied by the manufacturer in a silver foil pouch (Chirocaine, Abbott Laboratories).
The combination of fentanyl and levobupivacaine is supplied as a 500ml minibag by the ‘specials’ division of Fresenius Kabi in a striped wrapper. The fentanyl/levobupivacaine combination is stable in solution and in this presentation (minibag). This stability data is necessary for the manufacturer to ensure that their supply does not go out of date before use. In most clinical settings, a shelf life of one year would be suitable but staff must remember to rotate stock.
The two different volumes (200ml, 500ml) were chosen deliberately to provide a contrast between the two presentations. The opioid-containing bag is stored in a locked cupboard that meets or exceeds regulations (Department of Health, 2007) while the plain local anaesthetic-only bag is stored in a separate locked cupboard that is clearly labelled and is geographically isolated from infusions for IV use (NPSA, 2007).
Initiating the infusion
The majority of epidural infusions are started in the operating theatre or the recovery room. Registered staff (nurses and operating department practitioners) may only initiate an epidural infusion if they meet the following criteria:
- They have attended the local IV therapy study day and have successfully completed drug calculations;
- They have attended the local epidural study day;
- Staff have completed the medicines administration competency (level 3.1);
- They have completed the epidural competency (level 3.1).
The infusion is delivered using a dedicated yellow infusion device (Hospira’s GemStar infusion system) as recommended by the NPSA (2007) via a yellow striped administration set. The epidural infusion device has been programmed for epidural infusion use only. Preset parameters devised by the pain service prevent a bolus-only programme, such as that used for patient-controlled analgesia (PCA), being programmed through the epidural device. This action should prevent PCA being initiated with an incorrect infusion device.
The catheter and administration set are clearly labelled with ‘EPIDURAL’ stickers (black text on a yellow background). The patient’s primary prescription chart used for all other medicines is labelled on the front page with a similar ‘EPIDURAL CHART ALSO IN USE’ sticker.
To complement the introduction of the commercially prepared infusates, a combination prescription (Fig 1), troubleshooting guide (Fig 2) and a nursing assessment document were developed. The content of the document was approved by the drugs and therapeutics committee. The design of the final document was undertaken by a graphic designer.
The international convention for regional analgesia is to use the colour yellow and this has been incorporated where possible into all aspects of the management of epidurals, including the prescription chart. The leading edge of the front page uses colour to draw the reader’s eyes towards the word EPIDURAL. The use of a variety of colours (shades of blue and brown) was suggested by the designer to make the chart instantly recognisable and to make it an attractive patient assessment document that staff would want to complete. One of the frustrations of working in pain management is that, although patients may have their pain assessed by staff, it is often unrecorded. This revised document contrasted sharply with the previous black and white photocopied epidural record of assessment.
Fig 1 illustrates the limited choice of infusates that are currently available to prescribers. An anaesthetist or a member of the acute pain service may wish to reduce the concentration of fentanyl (from 4mcg/ml to 2mcg/ml) that a patient receives because of their age. Or they may wish to change the opioid because of inadequate analgesia (for example, from fentanyl to diamorphine), or remove the opioid completely, perhaps because of intractable pruritus or nausea. The choice of the plain levobupivacaine bag allows prescribers to do this. The insertion level and depth of the epidural catheter is recorded on this page and allows the pain service to easily determine if the catheter has migrated without the need to consult the anaesthetic record.
The troubleshooting guide (Fig 2) allows nursing staff to access guidance about caring for patients with epidural analgesia at the bedside. Evidence-based advice about the management of patients experiencing pruritus, hypotension or altered sensation or loss of motor power in limbs is provided. The frequency of observations is also outlined.
Assessing the impact of changes
Regular prospective audit is undertaken to ensure that patient assessment is carried out and recorded. Pain intensity scores at rest and on movement are compared against previous audit findings and the results shared with anaesthetic, surgical and nursing colleagues. Medication-related adverse events are all reported and discussed every three months by the MSI group. Serious analgesia-related events are reported immediately to the senior nurse for pain management, who is responsible for exploring the event as well as devising and implementing an action plan. The significant reduction in adverse events since the changes related to epidural analgesia has been previously reported (Cox et al, 2007).
Staff attendance at the epidural study day and completion of the competency document are subject to continuous review. The need to provide an update session for staff who last attended the study day more than three years ago was highlighted. These staff members have been able to attend a two-hour update session that focuses on patient selection criteria, pharmacology, troubleshooting and patient safety. Recent trends in adverse incidents are reviewed and discussed at the update session.
Implications for nursing practice
Nurses should implement the following practical advice:
- Where possible, use commercially prepared epidural infusates to reduce the risk of concentration errors and contamination;
- Store epidural infusions in a separate cupboard away from intravenous fluids;
- Keep up-to-date by attending an epidural update session and ensure your competency-based assessment has been completed;
- Pre-printed epidural prescriptions can facilitate streamlined prescribing;
- Use a dedicated infusion device and a yellow administration set for epidural analgesia.
Epidural analgesia can be a safe, effective means of providing pain relief after surgery. The role of the multidisciplinary acute pain team is to provide guidance and minimise the risks associated with epidural analgesia and ensure that NPSA recommendations and those of professional societies are adhered to in clinical practice. Clinical leadership and project management skills are necessary to ensure that practices are optimised and that all staff are aware of the importance of these changes and the potential for enhancing patient safety.
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