Ouch! Why is it so hard to assess children's pain?

The simple answer it is difficult to assess pain full stop, because pain is by definition subjective, the classic definition being that it is whatever the experiencing person says it is.  With children of course there is the added complication of developmental issues, in particular the inability to verbalise pain.

To get round this, there are a large number of different pain assessment tools and scales, ranging in complexity from a straight line with no pain at one end and the worst imaginable pain at the other; to quite sophisticated behavioural tools, which try to identify behaviours associated with pain.  The problem remains though; how do you know when someone who can't verbalise pain is in pain, and how do you know your treatment is working?

A new study has looked at two tools that are fairly commonly used, a 'faces' scale and a colour intensity scale.  The first has faces that reflect differing degrees of discomfort; the second a graduated colour scale, where more intense colour is associated with greater pain.  In my travels around hospitals in the UK, I have to say that I see these scales a lot, but I rarely see them actually used.  Never mind lets press on with the study.

They looked at the reliability and validity of these tools in children aged between 4 and 17 years in the United States who had painful and non-painful conditions; and compared the two tools.  When you are assessing how useful tools such as this are, there are two key things that people look for:

1. Validity - is it actually measuring what you think it is (in this case is it measuring pain, or might it be measuring something else, such as mood?)
2. Reliability - how consistent is it, in other words if you measured the same thing twice at the same time, would you get the same answer?

They actually did some quite sophisticated tests here, and found that overall the tools seemed to work quite well.  However, there is a but..

Firstly, the children were quite old; and there was least agreement between the tools in the youngest age-group, which is the very children in which it is hardest to measure pain.  Secondly, validity is context specific.  Just because it works with these children in this place at this time, it does not mean it is going to work elsewhere.  Watch for this one, the famous 'validated tool' which people talk about without often knowing the circumstances of the validation.  For example, a tool validated among old people in New York is not likely to be valid for children in Bolton.  You may think this sounds far fetched (and it is a bit) but I have seen similar claims made.  Lastly just because two tools agree, it doesn't make them right - they could both be wrong.  Often people refer to a 'gold standard' measure and compare a new measure to this, but even then there can be problems, for example the existing standard may itself not be very good.  Everyone 'agreed' about banking 5 years ago - it is just a shame that they were all wrong.

For parents my suggestion is to know your child's pain behaviours, and make sure that when you are with healthcare professionals you make them know that you know!

Tsze (2013) validation of self-report pain scales in children.  Pediatrics 132 e971-979

Guidlines-keep them simple otherwise we won't remember them! The example of weight estimation.

One of the most important variables in paediatrics is development, and one important measure of physical development is weight.  This is used for all sorts of things, including drug doses, fluid calculations and body surface area estimation.  Normally of course we can weigh children, so this should be pretty accurate.

Unfortunately, sometimes we can’t do this, most notably in emergency situations; and in such cases it is necessary to estimate the child’s weight.  While this is never going to be as accurate as weighing the child, a good estimate is the best that can often be achieved.  However, this obviously requires two things: 

1. A formula for estimating weight
2. That the person using it can remember it and use it correctly.

A number of methods for estimating weight exist, however a recent letter published in Archives of Disease in Childhood describing a survey among 25 paediatric trainees suggest that this may be a cause of some confusion.   The authors start by reviewing the current Advanced Paediatric Life Support (APLS) Guidelines, which contain three methods of estimating weight:

·         Infants from 1-12 months (0.5 x age in months +4)

·         Children aged 1-5 years (2 x age in years +8)

·         Children aged 6-12 years (3 x age in years +7)

These replace the previous Guidelines which had one formula for children aged 1-10 years, and which still used in some Guidelines.

The study found that only 2 of the participants (8%) were able to correctly apply the new formulae to examples that they were given, and that around half used the old formula.  The extent to which this matters is debatable, but clearly someone thought it was worth changing the guidance on this, and this is what is now taught, so one would expect that paediatric trainees at least would know them.

The lesson from this is that Guidelines should always be as simple as possible if we expect people to remember them.  For parents, it might be worth knowing roughly how much your child weighs!

How accurate are the doses of medicines given to children?

An interesting letter in Archives of Disease in Childhood published online ahead of print publication goes some way to answering that very question, and the answer is, in many cases not very.

An audit of children's wards at two hospitals in England looked at the doses of liquid medicines that were prescribed, and how easy these were to give using the syringes available on the ward.  For example, one 1.48 mg dose of morphine which came in a concentration of 10 mg/mL should have been 1.48 mL - a dose that was not possible to give accurately with either a 1 mL or 2.5 mL syringe, requiring either rounding up/down, or the use of two syringes.

Across all of the drugs given 34% of antimicrobials, 25% of analgesics; 11% of steroids and 5% of sedatives were not accurately measurable using the syringes available.  This leads to two issues:

1. The technical issue of whether an unmeasurable dose that is rounded up/down, and so which is  not really correct, is a prescribed wrongly or administered wrongly.  In crude terms 'whose fault is it?' (in a no blame, new open NHS kind of way).
2. Secondly, and of course much more important, is does it matter?  That depends on many things, the child; the dose; the amount of the rounding; other medicines that the child may be on....the list could go on and on.  Also when rounding up, do you round up to the line on the syringe, go half way through it, or go to the top of the line?

The other interesting thing that the authors speculate on is if it is like this in hospital, what might be going on in homes?   To this I would add the issue of crushed tablets; never recommended but it probably still goes on.

Does it matter?  Probably not in most cases, but the authors do conclude that research into the clinical implications of this would be helpful.  Probably the most important thing is not the variation per se, but the judgement of those giving the medicines.  The dangerous people are those who don't know what they don't know.

Challenging the paediatric ward discharge status-quo

One of the unwritten rules of paediatric medicine is that once a child is admitted to a ward they will stay over-night; and if they are ok they will bed and breakfast and probably go home the next morning.  That is one of the reasons that assessment and observation units were set up.  A recent paper in JAMA Pediatrics by Stephanie Iantorno and Evan Fieldston challenges this assumption, and in particular the idea that morning discharges are necessarily a measure of good practice.  One quote in particular seemed pertinent..."accommodating evening discharges can enhance the patient centeredness of care; families have obligations and barriers, including employment and transportation, that make morning discharges difficult and undesirable."

This seems to be one of the biggest challenges for health systems around the world - not just providing high quality care; but also care that fits in with today's lifestyles and expectations that things should happen when we want them to happen or when we need them to happen.  This is an American paper, and of course the health system there is very different to the UK; but the same challenges exist.  Some of this can be seen in the case of general practice hours - which often don't fit in with the hours of those who work in the day.  Another surprisingly important issue in London is avoiding the rush-hour; 07.00-10.00 and 16.00-19.00 are not good discharge times, particularly if one is relying on public transport!