A national survey of prevention of infection in obstetric central neuraxial blockade in the UK

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1 Anaesthesia, 2011, 66, pages doi: /j x ORIGINAL ARTICLE A national survey of prevention of infection in obstetric central neuraxial blockade in the UK A. G. McKenzie 1 and K. Darragh 2 1 Consultant Anaesthetist, Simpson Centre for Reproductive Health, 2 Consultant Anaesthetist, Royal Infirmary, Edinburgh, UK Summary We conducted a postal survey of all consultant-led UK obstetric anaesthetic units in August 2009, to assess the standard of aseptic technique used for neuraxial blocks. One hundred and sixty-four units responded giving a response rate of 76%; 93% of units ( ) follow recommended precautions and attach a bacterial micropore filter to the epidural catheter. Epidural top-ups are provided by 72% ( ) of units, with about two thirds using premixed solutions (of local anaesthetic with opioid) in a variety of ways: 51% (57 111) via a continuous infusion pump; 47% (52 111) by a prefilled syringe; and 23% (25 111) by multiple use of a premixed bag of solution. For spinals, 91% of units ( ) add diamorphine: of these 85% ( ) draw the diamorphine from non-sterile-wrapped ampoules. If required to draw opioid from a nonsterile-wrapped ampoule, 86% ( ) of units use a micropore filter and 21% (29 138) wipe the ampoule neck with an alcohol swab. Although sepsis secondary to neuraxial block in obstetric practice is uncommon (declared by 8.5% of units over an unspecified period of time), there is scope for further improvement.... Correspondence to: Dr Alistair G McKenzie alistair.mckenzie@luht.scot.nhs.uk Accepted: 25 February 2011 Infection is a rare complication of neuraxial block in obstetric patients but if it occurs, it is potentially catastrophic and disabling to the mother. A combined effort by the Royal College of Anaesthetists, the Royal College of Nursing, the Association of Anaesthetists of Great Britain & Ireland (AAGBI), the British Pain Society and the European Society of Regional Anaesthesia & Pain Therapy produced the guideline Good practice in management of continuous epidural analgesia in the hospital setting [1] in The publication of Safer practice with epidural injections and infusions by the National Patient Safety Agency (NPSA) occurred in 2007 [2], followed in 2008 by the AAGBI s publication Infection control in anaesthesia 2 [3]. In January 2009, the Royal College of Anaesthetists published the National Audit Project (NAP) 3 Report [4], with a chapter on complications after neuraxial block in obstetric practice, which included infection. Subsequent learning points and recommendations were stated. The aim of this survey was to ascertain the standard of aseptic practice in the UK, with reference to these national guidelines and recommendations. Methods Data were collected from a questionnaire sent, together with a covering letter, to the lead obstetric anaesthetist in 221 maternity units in the UK. Approval for the survey was obtained from the Obstetric Anaesthetists Association s Audit Subcommittee, which provided postal details. In the covering letter, each lead obstetric anaesthetist was asked to complete the questionnaire, commenting on the current practice in his or her unit. The questionnaire was designed to assess compliance with the current recommended good practice. The lead clinicians were asked to tick yes or no to questions and provide a few words of comment, where appropriate, with regard to practice in their maternity units. There were five sections of the questionnaire: Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 497

2 A. G. McKenzie and K. Darragh Æ Prevention of infection in obstetric central neuraxial blockade Anaesthesia, 2011, 66, pages facilities and practice in setting up epidural analgesia in the labour suite; management of epidural catheter disconnection; method of administering the epidural drugs, in particular the source of premixed epidural local anaesthetic with opioid and the precautions taken; the precautions taken with administration of spinal opioids; and lastly, an invitation to comment on any identified cases of sepsis involving neuraxial block. We wanted to include a question on the choice of antiseptic solution for disinfecting the patient s back, but this was the subject of another OAA survey. The questionnaire are given in the Appendix. Microsoft EXCEL was used to aid the data analysis. Results Two hundred and twenty-one questionnaires were sent out and 168 were returned. In four cases, the questionnaire was not completed as these hospitals did not offer an epidural service and thus, these questionnaires were discarded. The remaining 164 questionnaires were satisfactory for analysis, giving an overall response rate of 76%. Hand washing facilities with surgical scrub solution were available at (90%) of the maternity units in every labour room. Details of the aseptic precautions observed for insertion of an epidural catheter are presented in Table 1. A micropore filter was always attached to the epidural catheter by (93%) of respondents. Eleven respondents stated that this was not attached and there were four abstentions. With regard to the management of epidural catheter disconnection, some or all of the parts to this question were unanswered in 57 questionnaires. However, respondents would, for a brief period of disconnection, clean the catheter with antiseptic, allow to dry and then aseptically cut off a proximal portion before reconnecting (21 answered no, 15 abstentions). For a longer period of disconnection, respondents would remove the catheter and either resite or Table 1 Details of the aseptic precautions observed for insertion of an epidural catheter. Values are number (proportion) of respondents. Cap 143 (87%) Gown 163 (99%) Mask 149 (91%) Gloves 164 (100%) Insistence that assistant wears cap and mask 148 (90%) Sterile Drape 163 (99%) abandon the epidural (31 answered no, 24 abstentions). Only one respondent recorded that the decision to salvage the epidural depended on the level and movement of meniscus in the catheter (109 answered no, 54 abstentions). Nineteen respondents declared that it was mandatory to remove the catheter regardless of the period of disconnection (99 answered no, 46 abstentions). This information is shown in Fig. 1. Epidural top-ups were given at units with two abstentions, i.e. 72% ( ). Administration was as follows: at 24 units by anaesthetists only; at 37 units by midwives only; and at 55 units by both. Conversely, 28% of units (46 162) did not use epidural top-ups at all. Epidural infusions were used at 81 units, whereas 57 units used patient-controlled epidural analgesia (PCEA). Whereas half of all the units adopted just one method of administering epidural solutions, the other half offered a choice of methods (Table 2). The question on epidural top-ups of premixed solution was not applicable to 53 units. In 10 of the units using epidural top-ups, these were drawn from a bag of premixed local anaesthetic and opioid solution by multiple puncture. Of these, six units kept the bag in the labour room, two units kept it in the controlled drug cupboard and one unit kept it in the PCEA box. Syringes of premixed epidural solution were available at 52 units, and were obtained from the pharmacy in 23 units and from a commercial source in 29 units. The size of syringe was not declared by 33 of the units using this system. Single-use, small-volume syringes were used at 10 hospitals, five units using 10-ml syringes and five units using 20-ml syringes. A further nine units had 50-ml syringes, containing enough premixed solution for 3 5 epidural top-ups. At one hospital, the contents of a 100-ml bag were drawn into two 50-ml syringes: one of these was attached to the epidural catheter and the other stored in the controlled drug cupboard for up to 12 h. At another hospital, the 50-ml syringe was attached to the epidural catheter without disconnection, for bolus administration when necessary. At 57 units, epidural top-ups were administered from a bag via an infusion pump. The question on precautions taken for puncturing a premixed bag (as required for an epidural top-up) was answered by all 10 respondents, where this was usual practice. A further 15 respondents answered this question, implying that this was sometimes their source of epidural top-ups. Of the 10 respondents who stated that this was usual practice, six would wipe the injection port with an alcohol swab; this was also the practice of six of the other 15 respondents. Two respondents used a 498 Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland

3 Anaesthesia, 2011, 66, pages A. G. McKenzie and K. Darragh Æ Prevention of infection in obstetric central neuraxial blockade Figure 1 Management of accidental epidural filter disconnection. Grey: yes; black: no; white: abstained. Table 2 Different types of methods used for administering epidural solutions. Values are number (proportion) of units. Top-ups only 41 (25%) Infusions only 15 (9%) PCEA only 29 (18%) Top-ups + infusions only 51 (31%) Top-ups + PCEA only 13 (8%) Infusions + PCEA only 4 (2%) Top-ups + infusions + PCEA 11 (7%) PCEA, patient-controlled epidural analgesia dispensing pin attached to the bag. Two other respondents stated that they used a bacterial filter, that was attached to the injection port. Only six respondents declared that they would label the syringe into which the premixed epidural solution was drawn before use. With regard to precaution with administration of spinal opioids, 15 units did not use diamorphine. Of the remaining 149 units, 21 used sterile solutions of diamorphine prepared by the pharmacy. Two units were provided with sterile-wrapped ampoules of diamorphine powder. Regarding precautions in using opioid from a nonsterile-wrapped ampoule, 18 respondents did not answer the question, and a further eight recorded not applicable. Of the remaining 138, 29 wiped the ampoule neck with an alcohol swab before opening the ampoule and 119 used a micropore filter when drawing up the solution. A few wrote that they would use a particulate filter needle; this was not scored as use of a bacterial micropore filter. Fourteen units affirmed identification of cases of sepsis involving neuraxial block. Nine of these gave details: there were six cases of meningitis and three cases of epidural abscess. Discussion We have had to trust that the lead clinicians recorded the practice of the majority in their units. Of course, it is likely that not everyone in any particular unit does exactly the same thing. Our survey showed that there is room for improvement in provision of hand washing facilities, donning of cap and mask and insistence on the assistant also wearing a cap and mask, the compliance with these measures being in the range of 87 91%. Hospital policy for prevention of infection after neuraxial blocks in obstetrics has been described with meticulous attention to procedure by Benhamou et al. [5]. We were surprised that only 93% of units always attached a micropore filter to the epidural catheter. The 2004 guideline on good practice [1] stated that an antibacterial filter must always be used in the infusion line, at the junction of epidural catheter and infusion line (recommendation 5.9). When managing epidural catheter disconnection, the 2004 guideline on good practice [1] also advised that local protocols and guidelines should include the management of accidental catheter disconnection (recommendation 8.4). However, about one third of respondents failed to answer this question fully, indicating that many lack such a protocol. Nevertheless, the majority favoured (for a brief period of disconnection) cleaning with antiseptic, drying, cutting off the proximal portion with a sterile instrument and then re-connecting, as suggested by Langevin et al. [6]. Only one unit agreed with considering the position of the meniscus, which was also suggested by Langevin et al.[6]. A wide range of methods was evident for administering epidural solutions, with many units using a Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 499

4 A. G. McKenzie and K. Darragh Æ Prevention of infection in obstetric central neuraxial blockade Anaesthesia, 2011, 66, pages combination of epidural top-ups, PCEA or continuous infusions. Of the 111 units where epidural top-up boluses were used, 23% drew the solution from premixed bags, but only about half would swab the access port before drawing the top-up solution into a syringe. Based on expert opinions Benhamou et al. suggested that frequent disconnections may cause hub colonisation [5]. Head and Enneking have drawn attention to the possibility of contamination of the infusate itself [7]. However, a study by Madeo et al on contamination of bags for continuous epidural infusion was reassuring [8]. The remaining units (47%) used prefilled syringes of varying size. Christie and McCabe pointed out that despite the presence of a filter, frequent syringe changes may be associated with a higher rate of epidural infection [9]. Although less of an infection issue, we were concerned that six units kept the premixed bag in the labour room, creating a potential risk of inadvertent intravenous administration. The report of the Confidential Enquiry into Maternal and Child Health included a death resulting from intravenous infusion of bupivacaine that was intended for the epidural route [10]. It is also noteworthy that only 6 25 respondents (24%) would label the syringe into which the premixed epidural solution was aspirated. The NPSA alert 21 listed wrong-route incidents, including epidural medicine administered by the intravenous route and vice versa [2]. Both of these errors could potentially occur as a result of a syringe containing premixed epidural solution not being labelled. When administering spinal opioids, 21% of respondents would swab the ampoule neck with alcohol if opening and drawing up solution from a nonsterile-wrapped ampoule of opioid for intrathecal use. Hemmingway et al. reported that this manoeuvre was effective in preventing contamination, and that the effect of a filter straw in addition was less certain [11]. However, 86% of units would use a micropore filter. It must be pointed out that a micropore filter is a 0.2-lm bacterial filter, whereas a particulate filter needle has a less fine filter of 5-lm diameter [5]. Meningitis and epidural abscess are considered to be rare complications in UK obstetric practice. This survey reveals 8.5% of units declaring incidents over an unspecified period of time. It is possible that some respondents may have declared cases from their past experience at other hospitals, which possibly overlap. Schroeder et al. have reported a case of epidural abscess following epidural analgesia for labour, with advice on management [12]. A learning point from the NAP3 Report was that neuraxial infection may occur despite full aseptic practice, and that multiple attempts at inserting a neuraxial block, especially when accompanied by significant bleeding, may well be a factor. Extra vigilance is required in such cases [4]. Acknowledgements We thank the Obstetric Anaesthetists Association for providing the mailing list and all the lead obstetric anaesthetists who responded to the questionnaire. No external funding and no competing interests declared. References 1 Royal College of Anaesthetists, Royal College of Nursing, Association of Anaesthetists of Great Britain and Ireland, British Pain Society, European Society of Regional Anaesthesia & Pain Therapy. Good Practice in the Management of Continuous Epidural Analgesia in the Hospital Setting, November publications/guidelines/docs/epidanalg04.pdf (accessed 11/05/2009). 2 National Patient Safety Agency. Patient Safety Alert 21. Safer Practice with Epidural Injections and Infusions, Available at: (accessed 11/05/2009). 3 AAGBI Safety Guideline. Infection Control in Anaesthesia 2 (Originally published in Anaesthesia 2008; 63: ). 4 Royal College of Anaesthetists. Report and Findings of the Third National Audit Project: Major Complications of Central Neuraxial Block in the UK, January rcoa.ac.uk/docs/nap3_web-large.pdf (accessed 11/05/2009). 5 Benhamou D, Mercier FJ, Dounas M. Hospital policy for prevention of infection after neuraxial blocks in obstetrics. International Journal of Obstetric Anesthesia 2002; 11: Langevin PB. How should we handle epidural solutions? One view. Regional Anesthesia and Pain Medicine 2000; 25: Head S, Enneking FK. Infusate contamination in regional anesthesia: what every anaesthesiologist should know. Anesthesia and Analgesia 2008; 107: Madeo M, Samaan AK, Allison W, Wilson JA, Martin CR. Contamination of bags for continuous epidural infusion. Acute Pain 1999; 2: Christie IW, McCabe S. Major complications of epidural analgesia after surgery: results of a six-year survey. Anaesthesia 2007; 62: Lewis G (ed). The Confidential Enquiry into Maternal and Child Health (CEMACH). Saving Mothers Lives: Reviewing Maternal Deaths to Make Motherhood Safer London: CEMACH, (accessed 11/05/2009). 500 Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland

5 Anaesthesia, 2011, 66, pages A. G. McKenzie and K. Darragh Æ Prevention of infection in obstetric central neuraxial blockade 11 Hemmingway CJ, Malhotra S, Almeida M, Azadian B, Yentis SM. The effect of alcohol swabs and filter straws on reducing contamination of glass ampoules used for neuraxial injections. Anaesthesia 2007; 62: Schroeder TH, Krueger WA, Neeser E, Hahn U, Unertl K. Spinal epidural abscess a rare complication after epidural analgesia for labour and delivery. British Journal of Anaesthesia 2004; 92: Appendix Questionnaire used in the survey Please tick appropriate box. Some options require a few words of comment. In your maternity unit: Yes No 1. Do you have hand washing facilities with surgical scrub solution available in every labour room? 2. When inserting an epidural, what aseptic precautions are taken? a. Cap b. Gown c. Mask d. Gloves e. Insistence that assistant wears a cap and mask f. Sterile drape g. Any other precautions (specify.) 3. Is a micropore filter always attached to the epidural catheter at the time of insertion? 4. Describe your protocol of management in the event of the micropore filter becoming detached from the epidural catheter a. If brief period of disconnection: clean catheter with antiseptic, allow to dry and cut off cm with a sterile instrument, then re-connect. b. If period of disconnection longer: remove the catheter and either resite or abandon. c. Decision to salvage the epidural depends on level and movement of meniscus in catheter. (Explain.) d. Regardless of period of disconnection, it is mandatory to remove the catheter and either resite or abandon. 5. Do you use?: a. Epidural top-ups i. by anaesthetists ii. by midwives b. Epidural infusions This survey has the OAA Seal of Approval Survey No: 93 approved Prevention of infection with epidurals and spinals a national survey of practice in obstetric units c. Patient-controlled epidural analgesia Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 501

6 A. G. McKenzie and K. Darragh Æ Prevention of infection in obstetric central neuraxial blockade Anaesthesia, 2011, 66, pages If you use top-ups of premixed epidural solution, what is the source of the top-ups? a. Drawn from bag by multiple puncture If yes, where is bag stored between uses.. b. Single-use small volume i. prepared by pharmacy (specify drugs and concentration) ii. commercial preparation (specify drugs and concentration) c. Bag via infusion pump 7. If top-ups are drawn from a premixed bag, do the staff?: a. Wipe the injection port with alcohol swab b. Attach a dispensing pin to the injection port c. Attach a filter device to the injection port d. Label the syringe before use 8. When performing a spinal with diamorphine added to the local anaesthetic, what is the source of the diamorphine? a. Sterile volume prepared by pharmacy b. Drawn from non-sterile-wrapped ampoule 9. If opioid for a spinal is drawn from a non-sterile-wrapped ampoule, state the precautions taken. a. Ampoule neck wiped with alcohol swab b. Use of micropore filter 10. Have you identified any cases of sepsis relating to epidural or spinal insertion in obstetrics? Thank you. Single-use small volume Please give details.. Yes No 502 Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland