Improving the Safety of Magnesium Sulphate Injection: A

1

A Failure Modes and Effects Analysis (FMEA)

of the use of Magnesium Sulphate injection

August 2013

2

Contents

Page number

1. Executive summary 3

2. Introduction 4

• Objectives

• Scope

• Procedure/Methodology

3. Method of analysis 7

4. Findings: Significant failure modes identified 7

5. Limitations of the FMEA 8

6. Discussion 8

7. Recommendations 9

8. Conclusions 12

9. Acknowledgements 12

10. References 13

11. Further reading 14

12. Appendices 15

3

1. Executive summary

High-risk medications are those that pose an increased risk of causing significant

patient harm when used incorrectly. Although mistakes may or may not be

common with these medications, the consequences of such mistakes may be

much more devastating1. Based on incident reports submitted regionally and

nationally, and from the literature worldwide, injectable magnesium sulphate is

well known to be one such high-risk medication2.

Medication incidents have occurred in Northern Ireland hospitals with injectable

magnesium sulphate, resulting in varying degrees of patient harm. While

intravenous (IV) magnesium sulphate is widely used to treat a number of

indications such as arrhythmias, asthma, hypomagnesaemia, eclampsia and

neuroprotection of the fetus in the management of preterm labour, it is very

effective when used safely, however it has the potential to cause serious harm or

death when used incorrectly.

Following a Serious Adverse Incident involving IV magnesium sulphate and with

an awareness of other related incidents, the NI Medicines Governance Team

undertook a Failure Modes and Effects Analysis (FMEA) into the use of IV

magnesium sulphate in an attempt to identify the major risks involved in its use,

and to develop recommendations that might reduce the likelihood of future

medication incidents. This was endorsed by the Heads of Pharmacy & Medicines

Management across all 5 HSC Trusts.

Failure Modes and Effects Analysis (FMEA) is a structured prospective risk

analysis tool that has been widely used within the aerospace and automotive

industries and has more recently been utilised within healthcare since the early

1990s. It involves a multidisciplinary team mapping out a high-risk process of care

and identifying the failures that can occur. Each of these failures is then

characterised in terms of likelihood of occurrence, detectability and severity of

effects, and a risk priority number assigned to each of them. The resultant score is

then used to identify those failures most in need of attention3.

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2. Introduction

• Objectives

To improve patient safety through the identification of actions to reduce

medication errors in the use of IV magnesium sulphate.

• Scope

To evaluate the risks associated with the prescribing, dispensing,

administration and monitoring of IV magnesium sulphate, and to make

recommendations to reduce those risks considered to be associated with the

highest degree of potential harm to patients.

• Procedure/Methodology

Before starting the FMEA the NI Medicines Governance Team reviewed and

collated available information regarding risks relating to the use of IV

magnesium sulphate.

The team collated and analysed all medication incidents involving IV

magnesium sulphate reported in Northern Ireland during the period 01/04/08 to

31/03/11 inclusive.

A request was then submitted to the National Patient Safety Agency for

information/data on reported incidents in the UK taken from the NRLS

(National Reporting and Learning Services) database.

Professor David Cousins, Head of Safe Medication Practice and Medical

Devices, NPSA (May 2011) shared this information with the team which

allowed for a national perspective on the problems occurring with IV

magnesium sulphate.

5

Following analysis of the NI incidents, the following types of incident were

found to be the most common:

Type of medication incident Number of incidents

Incorrect dose – overdose 5

Incorrect rate – too fast 5

Incorrect patient 2

Incorrect drug 2

Incorrect route 1

Incorrect storage 1

Omitted medicine during stay 1

A literature review was also carried out by the NI Medicines and Poisons

Information Service, BHSCT, into medication incidents involving IV magnesium

sulphate.

The FMEA

FMEA is a systematic, proactive method for evaluating a process to identify

where and how it might fail, and to assess the relative impact of different

failures in order to identify the parts of the process that are most in need of

change. FMEA includes review of the following: 4

- Steps in the process

- Failure modes (What could go wrong?)

- Failure causes (Why would the failure happen?)

- Failure effects (What would be the consequences of each failure?)

The NI Medicines Governance Team (Appendix 1) met initially to map the

different steps involved in the use of IV magnesium sulphate (Appendix 2) and

the following steps were agreed as those accurately describing the overall

process:

Step 1: Decision to treat

Step 2: Prescribing IV magnesium sulphate

Step 3: Stock supply/Non-stock supply/Out-of-hours supply

Step 4: Preparation

6

Step 5: Administration

Step 6: Monitoring

Step 7: Treatment of toxicity

For each step in the process, all possible ‘failure modes’ were listed, including

minor and rare problems. Then, for each failure mode listed, all possible

‘failure causes’ were identified and the ‘failure effects’ of each of these were

also recorded.

The next stage in the FMEA process was to assign a ‘Risk Priority Number’

(RPN) to each of the failure modes. This is a numerical value based on the

likelihood of occurrence, likelihood of detection and severity of effects;

assigning a numerical value allows for prioritisation of the risks identified.

The documentation used to collate the information gathered throughout the

FMEA is shown below.

Step in process

Failure mode

Failure causes

Failure effects

Likelihood of occurrence

(1-10)

Likelihood of detection

(1-10)

Severity (1-10)

RPN

In order to ensure that each failure mode was considered in the correct

context, a multidisciplinary team (Appendix 3) was invited to meet with 2

members of the Medicines Governance Team to complete the FMEA. This

collaborative approach brought together expertise from other professionals in

the medical, nursing, midwifery and pharmacy fields to help ensure all aspects

in the use of IV magnesium sulphate injection were considered.

An information resource pack was distributed to the multidisciplinary team

members explaining the methodology of FMEA including guidance on the

‘scoring’ of the 3 parameters: likelihood of occurrence, likelihood of detection

and severity of effects, with each score being assigned a value between 1 and

10 (Appendix 4).

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3. Method of analysis

The RPN for each failure mode was calculated by multiplying the scores

obtained for each parameter. Those with the highest RPN values (150 and

above) were then considered in more detail as it is these particular failures

which would be associated with most risk.

The completed FMEA can be found in Appendix 5 where the RPN values

ranged between 1 and 384, with the top 10 RPN values highlighted in yellow

(i.e. RNP ≥ 150)

4. Findings: Significant failure modes identified

When collated, those RPN ≥ 150 were used to identify the failure modes as

having the greatest potential to cause harm and these were as follows:

Failure mode Step involved RPN value (and indication for IV magnesium sulphate)

Delay in decision Step 1: Decision to treat 150 (hypomagnesaemia)

Wrong dose Step 2: Prescribing IV magnesium

288 (hypomagnesaemia)

Wrong rate 288 (hypomagnesaemia)

Wrong patient 150 (hypomagnesaemia)

Wrong product ordered Step 3b: Non-stock supply


Wrong product selected on ward module


Wrong product selected in pharmacy


Calculate wrong volume of magnesium prescribed

Step 4: Preparation 224 (hypomagnesaemia)

Failure to do second check

Step 4: Preparation and Step 5: Administration

384 (all indications) 256 (all indications)

Failure of second check 384 (all indications)

Wrong pump setting Step 5: Administration 288 (pre-eclampsia) 180 (hypomagnesaemia) 252 (asthma)

Failure to monitor Step 6: Monitoring 160-200 (pre-eclampsia) 200 (hypomagnesaemia) 175-200 (asthma)

Failure to treat toxicity Step 7: Treatment of toxicity

200 (pre-eclampsia, hypomagnesaemia, asthma)

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5. Limitations of the FMEA

The FMEA process uses a hypothetical approach to understanding the

risks involved in a process, compared to other risk management tools such

as Root Cause Analysis which use actual data/information to understand

the problems involved.

The FMEA did not risk assess the unlicensed use of intravenous

magnesium sulphate for the neuroprotection of the fetus in the

management of pre-term labour. This indication for the use of intravenous

magnesium sulphate was identified during the development of this report.

Nor did it address the use of magnesium sulphate injection in total

parenteral nutrition (TPN).

The FMEA did not seek to evaluate the impact of implementation of any of

the recommendations.

6. Discussion

It became apparent as the FMEA was nearing completion that certain aspects in

the use of IV magnesium sulphate carried much greater risks than others. For

example, if only those RPN values > 200 are considered from the table above,

then we can make the following generalisations from the results:

Ensuring the dose and rate are correct are the key steps in the prescribing

process. The variety of measurement units in which dosage of this

electrolyte may be expressed makes potentially fatal dosing errors more

likely5.

Calculation of the volume of magnesium sulphate solution to use in the

preparation of the magnesium sulphate infusion is crucial in the safe

preparation and administration of IV magnesium sulphate, as is the

accurate setting of the infusion device.

The importance of having an independent second check carried out at the

preparation and administration stages, regardless of who is preparing

and/or administering the preparation, adds an extra safety barrier into the

overall process, and could be the difference between the patient receiving

the correct dose and a harmful incorrect dose.

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7. Recommendations

Following consideration of all the failure modes recognised in each step of the

process where the RPN ≥ 150, and the associated failure causes identified

with these failure modes, the following recommendations are made.

Those recommendations which are specific to the use of IV magnesium

sulphate are highlighted in bold followed by other recommendations relevant to

safe medication practice.

Recommendations

Ensure all wards/clinical areas have readily available access to

clinical guidance on the safe use of IV magnesium sulphate for the

indications being treated.

Laboratory staff should ensure that reliable systems are in place to

communicate all abnormal laboratory test results to the relevant medical

practitioner looking after the patient.

Recommendations

Trusts should ensure that clinical guidelines are in place to

support the safe prescribing of IV magnesium sulphate in all

settings (e.g. hypomagnesaemia, asthma, arrhythmias, severe pre-

eclampsia, eclampsia and neuroprotection of the fetus in the

management of preterm labour) including guidance on the

required dose and rate of infusion, and conversion between

different expressions of units.

Consensus should be reached on suitable pre-prepared IV

magnesium sulphate infusions for the required indications, which

should then be prescribed.

Step in process: Decision to treat

Failure mode: Delay in decision

Step in process: Prescribing IV magnesium sulphate

Failure mode: Wrong dose/wrong rate/wrong patient

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Magnesium sulphate injection and pre-prepared infusion strengths

should be expressed in mmol and grams in all electronic

prescribing systems to reduce confusion in magnesium dosing.

Ensure treatment plans are written clearly in the patient’s medical notes,

medication charts or any other record used to document treatment

decisions/information.

Ensure all relevant laboratory results are correlated with the correct

patient before prescribing new treatment.

The kardex should always be checked against the details of the patient

before prescribing to ensure the correct kardex is used when

prescribing medication.

A clinical pharmacist check of prescribed medication should be carried

out at ward level where feasible.

Recommendations

Magnesium sulphate injection and pre-prepared infusion strengths

should be expressed in mmol and grams in all electronic

dispensing systems to reduce confusion in magnesium dosing.

All non-stock requisitions for IV magnesium sulphate should be

clinically checked by a pharmacist, against the patient’s kardex

where feasible.

Trusts should ensure that storage of IV magnesium sulphate is

risk assessed to minimise mix-ups between IV magnesium

sulphate products or other pharmaceuticals stored in the same

area, taking into consideration the product packaging.

Step in process: Non-stock supply

Failure mode: Wrong product ordered/wrong product selected on ward

module/wrong product selected in pharmacy

11

Recommendations

Pre-prepared magnesium sulphate infusions should be procured

and used wherever possible in accordance with prescribing

consensus.

Magnesium sulphate injection should be removed from ward stock

and replaced with pre-prepared IV magnesium sulphate infusions

in accordance with prescribing consensus.

Where pre-prepared magnesium sulphate infusions are not

available, calculation of the volume of magnesium sulphate

solution required to prepare the IV infusion should be carried out

carefully. It is very rare that ‘more than 3’ vials/ampoules of

magnesium sulphate injection would be required to prepare an

infusion, even at the higher doses6,7. For this reason it is

imperative that all calculations are independently second checked

by another member of medical/nursing/pharmacy staff.

The second check of medicine preparation and administration

should include the following: right patient, right route, right dose,

right volume of magnesium sulphate solution required to prepare

the dose, right final volume, right infusion fluid, right rate of

administration and right rate setting on the infusion device.

Bolus doses of IV magnesium sulphate must never be

administered from an infusion preparation where both a bolus and

infusion are to be given.

Confusion between the different expressions of strength of

magnesium sulphate injection can lead to calculation errors. Staff

involved in the preparation of magnesium sulphate bolus

injections and/or infusions should check with a more senior

colleague if unsure about any aspect of the strength of magnesium

sulphate injection when preparing the dose.

Staff should avoid distractions/interruptions during the preparation of

medicines.

Step in process: Preparation and administration

Failure mode: Calculate wrong volume of magnesium sulphate solution

required to prepare dose/failure to carry out second check/failure of

second check/wrong pump setting

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Consideration should be given to the use of smart pumps in the

administration of IV medicines.

All staff must be encouraged to challenge staff regarding the

preparation of medicines where they feel has been inaccurately

prepared/administered.

Recommendations

Trusts should ensure that clinical guidelines are in place to

support the safe prescribing of IV magnesium sulphate in all

settings (e.g. hypomagnesaemia, asthma, arrhythmias, severe pre-

eclampsia, eclampsia and neuroprotection of the fetus in the

management of preterm labour) including guidance on the normal

reference range for magnesium, the monitoring requirements

when IV magnesium sulphate is prescribed, signs of toxicity, how

to treat toxicity and availability of the antidote (calcium gluconate

10%).

8. Conclusions

FMEA facilitated the identification and prioritisation of risks with the use of

injectable magnesium sulphate. Recommendations have subsequently been

developed, aimed at reducing medication errors with magnesium sulphate

injection in secondary care in Northern Ireland.

9. Acknowledgements

The Regional Medicines Information Service undertook a literature review of

medication incidents involving intravenous magnesium sulphate.

David Cousins, Head of Safe Medication Practice, National Patient Safety Agency,

provided medication incident data from the National Reporting and Learning System.

Step in process: Monitoring and the treatment of toxicity

Failure mode: Failure to monitor/failure to treat toxicity

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10. References

1 Pathways for Medication Safety. www.medpathways.info

2 Implementation of a High-Alert Medication Program. The Permanente Journal.

Spring 2008. Volume 12 No.2

3 Failure mode and effects analysis outputs: are they valid? BMC Health Services

Research 2012, 12:150 NA Shebl, BD Franklin, N Barber.

4 Failure Modes and Effects Analysis (FMEA). Institute of Healthcare Improvement

2004

5 Magnesium sulphate: Is that the right dose? American Journal of Nursing (AJN).

August 1997 – Volume 97 – Issue 8 – pp12-14. Linda L. Lilley, Robert Guanci

6 ISMP (Institute for Safe Medication Practices). Medication Safety Alert, 5th Nov

1997. http://search.ismp.org/cgi-

bin/hits.pl?in=517791&fh=80&ph=1&tk=y%22vXfb%20sruC%203%22&su=qevvrT--

xxx.uibr.Q_P-%3Aqxipqvvq_i-WVCvqVW_q-W_vuVpqi-

19971105.Wir&qy=p%22p%3AFE%20JP%26b%203%22&pd=1

7 ISMP (Institute for Safe Medication Practices). Medication Safety Alert, 14th July

1999. http://search.ismp.org/cgi-

bin/hits.pl?in=517791&fh=80&ph=1&tk=zCxj%3A%20Cxj%3APd%20MFwX%20MFw

XPd%203%20j%27v%3A%20j%27v%3APd%20j%27v%3Ad&su=w%3AjjCKVVMMM

.QaiC.vxbVJLMa_LjjLxaVPudjLuPxLVPxjQu_LaVD3g99DujQvJ.PaC&qy=fKEPn%20

w-HV%203%20PLWn&pd=1

http://search.ismp.org/cgi-bin/hits.pl?in=517791&fh=80&ph=1&tk=y%22vXfb%20sruC%203%22&su=qevvrT--xxx.uibr.Q_P-%3Aqxipqvvq_i-WVCvqVW_q-W_vuVpqi-19971105.Wir&qy=p%22p%3AFE%20JP%26b%203%22&pd=1




http://search.ismp.org/cgi-bin/hits.pl?in=517791&fh=80&ph=1&tk=zCxj%3A%20Cxj%3APd%20MFwX%20MFwXPd%203%20j%27v%3A%20j%27v%3APd%20j%27v%3Ad&su=w%3AjjCKVVMMM.QaiC.vxbVJLMa_LjjLxaVPudjLuPxLVPxjQu_LaVD3g99DujQvJ.PaC&qy=fKEPn%20w-HV%203%20PLWn&pd=1





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11. Further reading

The Ten Most Common Lethal Medication Errors in Hospital Patients. Hospital

Pharmacy 2000, 35(5), 470-474. Argo AL, Cox KK, Kelly NN.

Obstetrical accidents involving intravenous magnesium sulphate: recommendations

to promote patient safety. MCN Am J Matern Child Nurs. 2004 May-Jun;29(3):161-9;

quiz 170-1. Simpson KR, Knox GE.

Preventing magnesium toxicity in obstetrics. Hospital Pharmacy 2005, 40(12), 1028-

1031. Cohen M.

Shaken, not stirred. Hospital Pharmacy 2005, 40(7), 556-557. Cohen M.

Resident training for eclampsia and magnesium toxicity management: simulation or

traditional lecture? American Journal of Obstetrics & Gynecology 2010, SMFM

Papers 379.e1

Acute magnesium toxicity in an obstetric patients undergoing general anaesthesia

for caesarean delivery. Int J Obstet Anesth, 2010, Apr;19(2):226-31. McDonnell NJ,

Muchatuta NA, Paech MJ.

Inadvertent administration of magnesium sulphate through the epidural catheter:

report and analysis of a drug error. Int J Obstet Anesth, 2006, 15, 63-67. Goodman

EJ, Haas AJ, Kantor GS.

Hypermagnesenia in a paediatric patient. Anesth Analg 2000;91:1160-2. Harker HE,

Majcher TA.

Failure mode and effects analysis: too little for too much? BMJ Qual Saf, published

online March 23, 2012. Dean Franklin B, Shebl NA, Barber N.

Design of a safer approach to intravenous drug infusions: failure mode effects

analysis. Qual SAF Health Care, 2004;13:265-271. Apkon M, Leonard J, Probst L,

DeLizio L, and Vitale R.

FMEA: a new approach to manage high risk medicines. The British Journal of

Clinical Pharmacy Dec 2009, Vol 1. Williamson S, Wake N, Donovan G.

Towards standardisation of drug infusion concentrations in UK critical care units.

Journal of the Intensive Care Society, 2009, Volume 10, Number 3. Borthwick M,

Keeling S, Keeling P, Scales K, and Waldmann C.

Managing high-risk medications: implementing medication management standard

7.10. Hospital Pharmacy 2006, 41(5), 470-476. Shlom EA, May SK.

15

NI Medicines Governance Team members Appendix 1

Anna Lappin, Northern Health & Social Care Trust

Daryl Connolly, Western Health & Social Care Trust

Jillian Redpath, Southern Health & Social Care Trust

Sharon O’Donnell, Belfast Health & Social Care Trust

Aine Liggett, South Eastern Health & Social Care Trust

Angela Carrington (Team Leader) Belfast Health & Social Care Trust

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Process mapping of IV magnesium sulphate use Appendix 2

1. Decision to treat - based on lab results +/-

- clinical presentation of patient [consider Neonates & Paediatrics]

2. Prescribing - dose (mmol or gm) - rate of administration - volume of fluid - type of fluid - where to prescribe - kardex

- fluid balance chart

- recommendation in patients notes

- verbal recommendation from specialist e.g.

over the phone (does this include dose

guidance?)

3. Supply: stock supply/non-stock supply/out-of-hours (OOH) supply - ward top-up item or non-stock item - selection of correct medicine in dispensary - clinical check against kardex: Trust specific

4. Preparation - select medicines - read prescription - calculate volumes - withdraw from amps – Mg - query withdrawal of excess infusion fluid? - add Mg to infusion fluid - mix - label - 2nd check: Trust specific

5. Administration - identify patient - (2 steps) Bolus & maintenance - ensure IV access for eclampsia

- flush to ensure patency

- connect infusion – ensure correct line

- pump setting (large v small volume [bolus])

- infusion commenced

- document administration

- 2nd check: Trust specific

6. Monitoring - in accordance with requirements of guidelines or

- instructions of the prescriber (communication) - document

7. Treatment of toxicity if required - seek advice from specialist

***The FMEA did not address; the use of intravenous magnesium sulphate for the neuroprotection of the fetus in the management of pre-term labour or the use of magnesium sulphate injection

in TPN***

17

Multidisciplinary Team members Appendix 3

Anna Lappin, Medicines Governance Pharmacist, NHSCT

Daryl Connolly, Medicines Governance Pharmacist, WHSCT

Dr Francis McCarroll, Registrar, Physician, NHSCT

Dr Michael Ryan, Consultant Biochemist, NHSCT

Gillian Morrow, Practice Educator, Midwifery, BHSCT

Damien Holland, Staff Nurse, BHSCT

Majella Moohan, Clinical Pharmacist, BHSCT

Dr Kevin Glackin, ST6, Obstetrics, BHSCT

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Failure Modes and Effects Analysis Resources Appendix 4

Institute for Healthcare Improvement Information and tools available at:

http://app.ihi.org/Workspace/tools/fmea/

Institute for Safe Medication Practice Canada

Training presentation available at:

http://www.ismp-canada.org/download/ISMP_Canada_FMEA_presentation.pdf

Failure Modes and Effects Analysis (FMEA)

FMEA is a tool/process that was developed outside of healthcare but has been used

widely within healthcare to identify ways in which a process can fail.

FMEA looks at any given process, identifies possible or likely errors (failure modes),

and gauges what the consequences (effects) will be, even before they take place.

The aim is to predict where and how the process may fail, the causes of such

failures, and to examine the consequences of such failures. The severity of the effect

on the patient is then examined alongside the likelihood of occurrence and the

likelihood of detection of the failures, before assigning a risk score to each failure

mode (Risk Priority Number, RPN).

The process then finishes with producing a set of prioritised recommendations to be

implemented in order to eliminate the possibility of error, detect the error before it

reaches the patient, or minimise the harmful effects of the error on a patient.

FMEA Steps

1. Choose a multidisciplinary team

2. Construct a detailed flow chart of the process

3. Decide ‘how’ and ‘where’ the process can go wrong

- The failure mode is ‘What might happen’

- The cause is ‘Why it happens’

4. Determine the ‘effect’ of each failure

http://app.ihi.org/Workspace/tools/fmea/

http://www.ismp-canada.org/download/ISMP_Canada_FMEA_presentation.pdf

19

- Try to limit this to the true effect of the failure, not what the effect might be

5. For each failure ‘effect’

• Estimate the likelihood of occurrence (A)

• Estimate the likelihood of detection (B)

• Estimate the severity of effects (C)

Then calculate the Risk Priority Number (RPN)

RPN = A x B x C

6. Rank the ‘effects’ in order of RPN

7. Redesign systems to

• Decrease recurrence

• Decrease the severity

• Increase the probability of detection

8. Implement ‘new’ process

9. Audit new process for uptake

10. Repeat exercise to determine new RPN and monitor the RPN over time

against improvements in processes.

Tips

• Take small bites / keep it simple

• Think ‘what could possibly go wrong’ and/or ‘what has gone wrong frequently

in the past’

• Modifying a new process may create new risks

• Map quickly

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Scoring

(A) Likelihood of occurrence

Score Probability Description

1 1:1,000,000 Remote, no known occurrence

2 1:100,000 Very low, possible but no known data

3 1:100,000

4 1:10,000 Low, possible but infrequent documented occurrences

5 1:10,000

6 1:1,000 Moderate, documented occurrences

7 1:1,000

8 1:100 High, documented and frequent

9 1:10 Very high, documented almost certain

10 1:1 Extreme – will always occur

(B) Likelihood of detection

Score Probability Description

1 10:10 (100%) System will always detect error

2 8:10 (80%) High, likely to be detected before reaching the patient

3 7:10 (70%)

4 6:10 (60%) Moderate, moderate likelihood of detection before it reaches the patient 5 5:10 (50%)

6 4:10 (40%) Low likelihood of detection before it reaches the patient

7 3:10 (30%)

8 2:10 (20%) Very low likelihood of detection before it reaches the patient 9 1:10 (10%)

10 0:10 (0%) Detection not possible at any point within system

(C) Severity of effects

Score Description

1 Slight annoyance, may annoy the system

2 Moderate system problem, may affect the patient

3

4 Major system problem, may affect the patient

5

6 Minor patient injury

7 Moderate patient injury

8 Major patient injury

9 Terminal injury/patient death

10 Multiple terminal injury/death

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Intravenous Magnesium Sulphate FMEA (The top 10 RPN scores are highlighted in yellow) Appendix 5

Step in process

Failure mode

Failure causes Failure effects


(1-10)


(1-10)

Severity (1 – 10)

RPN

1. Decision to treat

Decide not to treat when they should

Lack of knowledge/ experience

Deterioration of clinical state

Pre-eclampsia = 1 HypoMg = 4 Asthma = 2 Arrhythmias = 1



24 100 28 27

No decision made to prescribe:

Overlooked - no level taken or - not acted on





24 100 28 27

Decide to treat when not appropriate

Lack of knowledge/ experience. - using before other treatment maximised (asthma)

Possible magnesium toxicity




4 48 48 8

Delay in decision

Delay in Lab results. Cannot contact specialist. Cannot find guidelines.





48 150 28 27

2. Prescribing IV Mg

Not prescribed

Forget. Decision not communicated to prescriber.





32 120 42 18

Delay in prescribing

Forget. Decision not communicated to prescriber.





32 120 42 36

22

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Wrong dose Illegibility in recommendation (notes). Lack of knowledge. Confusion with units (e.g. mmol/ml/G/%). Lack of regional/national guideline. (respiratory/ cardiology/ hypomagnasaemia). Lack of consistency between local guidelines. Failure to interpret guidelines correctly. BNF (info in different sections). Calculation. No pharmacist clinical check of prescription. Wide stock availability does not trigger further questioning of incorrect prescription.

Deterioration of clinical state (underdose) Toxicity (overdose)

Pre-eclampsia = 2 HypoMg = 3 Asthma = 3 Arrhythmias = 2 Pre-eclampsia = 2 HypoMg = 6 Asthma = 2 Arrhythmias = 2



32 90 84 48

64 288 64 32

23

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Wrong rate Calculation. Confusing guideline e.g. hours per day or per hour. Lack of knowledge. Lack of guideline. Illegibility in recommendation (notes). No pharmacist clinical check of prescription. Wide stock availability does not trigger further questioning of incorrect prescription.

Deterioration of clinical state (rate too slow) Toxicity (rate too fast)



Pre-eclampsia = 8 HypoMg = 5 Asthma = 7 Arrhythmias = 9 Pre-eclampsia = 8 HypoMg = 8 Asthma = 8 Arrhythmias =8

32 90 84 54

64 288 64 32

Wrong volume

Lack of knowledge. Lack of guideline. Illegibility in recommendation (notes). No pharmacist clinical check of prescription. Wide stock availability does not trigger further questioning of incorrect prescription.

Extravasation if too concentrated




40 60 60 5

24

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Wrong type of fluid

1 1 1 1

Not documented correctly

Location as to where it is prescribed – fluid balance chart / prescription. No pharmacist clinical check of prescription.

Repeated dose (toxicity) Omitted dose Delayed dose (underdose)




48 18 18 18

32 90 48 54

Wrong patient

Similar names. Not checking the kardex against the details of the patient to be treated. Mismatch between lab result and patient to be treated. Bed locations being quoted. Instruction on which patient to treat misheard. No pharmacist clinical check of prescription. Wide stock availability does not trigger further questioning of incorrect prescription.

Wrong patient receives Mag. Correct patient does not receive Mag.




32 150 32 9

25

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

3a. Stock supply Not ordered on top-up when level below top-up

Overlooked. Manual system.

Stock not available – delay in treatment or wrong product selected

Pre-eclampsia = 2 HypoMg = 3 Asthma = 2 Arrhythmia = 2



32 54 32 36

Ordered but not supplied

Overlooked at picking and checking stage. Manual system.





32 54 32 36

Wrong product supplied

Similar packaging with other medicines or wrong size ampoule. Poorly labelled product. Poor product description on computer. Wrong product ordered on top-up. Overlooked at picking and checking stage. Manual system.





32 54 32 36

Expired product supplied

Overlooked at picking and checking stage. Manual system. Lack of routine expiry date checks.

In date stock not available – delay in treatment or expired product administered




32 54 32 36

26

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

3b. Non-stock supply

Unclear requisition (minijet vs 2ml vs 10ml ampoule vs oral)

Unaware of different products. No clinical check against prescription in Pharmacy. No pharmacist screen on non-stock orders.

Delay in supply or wrong product supplied




4 54 4 4

Wrong product ordered

Confusion. No clinical check against prescription in Pharmacy. No pharmacist screen on non-stock orders.





4 162 4 4

Wrong product selected on ward module

Pick-list. Products poorly described on computer. Unaware of different products. Poorly documented prescription. No clinical check against prescription in Pharmacy. No pharmacist screen on non-stock orders.





4 162 4 4

27

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Wrong product selected in Pharmacy

Similar packaging. Wrong storage – another product in bin location. Manual check fails. Manual check not done. Non-ACT final checking requisitions (cf to stock request where only top-items can be ordered, NB not all hospitals label non-stock). Wrong product requested from robot. Lack of training of staff to check. Distraction.

Stock not available – delay in treatment or wrong product selected on ward




4 162 4 4

Sent to wrong ward

Misread/unclear/wrong ward on requisition. Placed in wrong pigeon hole. Pneumatic delivery fault.





32 54 32 36

3c. Out of hours supply

Select wrong product from emergency cupboard

Single check on selection from emergency cupboard.





4 54 4 4

28

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Wrong product borrowed from another ward

Ward don’t realise pharmacist input into non-stock supply. Have been told to borrow previously.





4 54 4 4

Wrong product supplied

Single check on supply by EDC pharmacist.





4 54 4 4

4 Preparation Read medicine name and dose incorrectly

Illegible prescription / handwriting (e.g. decimal point).

Delay Underdose Overdose

Pre-eclampsia = 2 HypoMg = 4 Asthma = 2 Arrhythmias = 2 Pre-eclampsia = 2 HypoMg = 2 Asthma = 2 Arrhythmias = 1 Pre-eclampsia = 2 HypoMg = 2 Asthma = 2 Arrhythmias = 2



32 80 28 36

32 40 28 16

32 64 32 16

Wrong selection

Incorrect storage of similarly packaged ampoules.

Underdose of magnesium or toxicity due to an unintended medicine

5

3

7

105

29

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Calculate wrong volume of magnesium prescribed

Calculation error. Misunderstanding of ampoule contents on label. Confusion between expression of units (mmol/ml/ G/ml/%). Unaware of ‘more than 3’ rule.

Underdose Overdose


Pre-eclampsia = 2 HypoMg = 4 Asthma = 2 Arrhythmias = 1 Pre-eclampsia = 3 HypoMg = 4 Asthma = 3 Arrhythmias =1


32 40 28 8

96 224 48 8

Withdraw wrong volume from ampoules

Slip or lapse. Distracted Interruption.

Underdose Overdose




32 40 28 16

48 48 48 8

Withdraw wrong volume of excess infusion fluid

Slip or lapse. Distracted Interruption.

Pre-eclampsia = 1 HypoMg = 1 Asthma = 1



10 10 2

Failure to mix thoroughly

Not aware of need. Overdose Extravasation




24 18 2

Unlabelled or incorrectly labelled infusion

Forget. No labels. Not routine practice.

Toxicity (Think just dealing with NaCl or glucose) Administered to wrong patient




120 96 96

30

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Failure to do Second Check

Not routine practice. Medical cf nursing staff.

Underdose Overdose Extravasation

6

8

8

384




4

8

8

256

Failure of second check

Knowledge. Distraction. Interruption. Incomplete. Culture. Cursory Check. Failure to challenge.


6 8 8 384

5 Administration

Failure to identify correct patient

Similar names. Not checking the kardex against the ID braclet. Bed locations being quoted.

Wrong patient receives Mag. Correct patient does not receive Mag.




96 60 84 9

No IV access

Venflon tissued. Lack of trained staff to cannulate.

Delay in treatment.




32 15 21 18

Failure to check patency

Forget. Unaware of policy.

Unable to administer Mag. Extravasation




16 10 14 18

Non-patent line

Poor line care. Patient related factors.

Unable to administer Mag.




16 10 14 18

31

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Wrong line Lack of line labelling process. Failure to trace line back to patient.

Magnesium administered via wrong route.




96 96 96 96

Wrong pump setting

Adjusted/set rate for another drug. Bolus rate continued. Operator error on pump. Lack of ‘smart’ pumps. Calculation error.

Magnesium administered at the wrong rate – Too Fast Magnesium administered at the wrong rate – Too Slow




144 144 144 8

288 180 252 9

Infusion not commenced

Distraction. Unfamiliar with pumps.

Magnesium not administered




120 75 42 9

Administration not documented

Forget. Documented on wrong document.

Dose administered again (bolus)




120 72 72 72



Wrong patient Wrong route Underdose Overdose Extravasation

6

8

8

384




6

8

8

384

32

Step in process

Failure mode



(1-10)


(1-10)

Severity (1 – 10)

RPN

Failure of second check

Knowledge. Distraction. Interruption. Incomplete. Culture. Cursory Check. Failure to challenge.


6 8 8 384

6. Monitoring Not done Forget. Lack of guidelines. Prescribers requirements not clearly documented.

Toxicity not detected Lack of effect not detected Incorrect rate not detected – overdose Underdose




160 200 200 32

200 125 175 32

Not acted on

Lack of knowledge. Lack of clear guidance.

Toxicity/lack of effect not recognised




64 120 64 32

Not documented

Forget. Document in wrong document.

Toxicity/lack of effect not recognised by others




64 64 64 64

7. Treatment of toxicity

Not treated Unaware of how to treat. Unaware of need to treat (severity of magnesium toxicity). Not seeking specialist advice.

Toxicity not treated




200 200 200 32

Documents

Improving the Safety of Magnesium Sulphate Injection: A