​

Hey Reader,

Welcome to another edition of Bursting The Bubbles, DTFB's newsletter with some top tips, evidence highlights, and the best dad jokes.

This week we look at dehydration, sleeping babies, and terrifying intubation moments.

Let's do it...

​

WEEKLY BUBBLE WRAP: HOW MUCH DO BABIES SLEEP?

​

What’s It About?

This longitudinal study aimed to define normal sleep parameters for healthy-term infants. This data was taken from the non-intervention arm of the BabySMART trial (RTC looking at massage therapy, sleep and neurodevelopment). Term babies with no NICU admission, no congenital or metabolic abnormalities and singleton pregnancy were eligible.

​

​

Parents of 106 infants completed sleep diaries capturing the duration and timing of each sleep episode from 4 to 16 weeks of age. Parental questionnaires assessed sociodemographics, sleeping arrangement, feeding status and parents’ perceptions of infant sleep. Total sleep time, day-time sleep (from 07:00-18:59), night-time sleep (from 19:00-06:59) and longest sleep in 24 hours were measured. Reference centiles for these parameters were created using multilevel linear mixed modelling and plotted against the infants’ ages.

​

Results showed variability between infants. From 4 to 16 weeks, total sleep increased by under 1 hour, daytime sleep decreased by nearly 2 hours, night-time sleep increased by 2.5 hours, and the longest sleep period increased by 3 hours.

​

By four weeks, 49% of infants were exclusively breastfed – this had dropped to 31% by 16 weeks. There was no difference in sleep patterns between infants exclusively breastfed, mixed feeding or receiving formula.

​

Most parents (80%) did not feel their child’s sleep pattern was problematic. This study relies on parental recall, which may be an underestimate or overestimate. This study also had a very specific demographic – white Irish babies. It is unclear if this can be extrapolated to a population of different ethnicities and cultures. It is important, too, that this data was taken from an RCT. Therefore, the initial plan for this data was not what this study looked at (good to think of as a spin-off series – good but not the intended initial outcome!).

​

Why does it matter?

Sleep is essential for early brain development. Many parents worry about ‘normal’ sleep patterns in babies.

​

Clinically Relevant Bottom Line

Parents can be reassured there is variability in sleep patterns between infants in the first few months. Shorter sleep episodes and mixed circadian rhythms evolve to more rhythmic day-night trends over this period. The feeding method does not appear to influence infants’ sleep.

​

Reviewed by: Bethany Davies and Hannay Cooney. Read the full Bubble Wrap here.

​

Get Your DFTB Essentials Ticket! Tickets for our online course are on sale now. ​ Live on 28th November with lifetime access. ​ The last few discounted tickets are available before the price goes up! I want my DFTB Essentials ticket!

TOPIC OF THE WEEK: ASSESSING DEHYDRATION

​

How good is the clinician’s gestalt if we clinically assess a child?

It has been suggested that doctors are right about 75% of the time when picking mild dehydration (under about 3%) and found difficulty differentiating severe dehydration from more moderate dehydration. But then, what is gestalt in this setting? It is just a collection of impressions formed by one’s subconscious mind processing the history and focused clinical exam.

​

Is that any better than the parents’ guess?

A prospective observational trial of 132 children-parent dyads had a similar sensitivity of about 73% to predict 5% dehydration. Parents don’t have the same experience as physicians concerning physical exam findings, so they were guided more by historical factors. Normal fluid intake and a history of normal urine output (normally the number of wet nappies) have a likelihood ratio of near zero. The child is highly unlikely to be significantly dehydrated if both are present.

​

What about skin turgor?

Turgor has been used to diagnose dehydration for over 50 years. When originally described by Laron in 1957, the examiner was supposed to pinch a small skin fold on the abdominal wall and watch for elastic recoil. Now most of us use the hand or forearm rather than the belly. But similarly, there is a wide variety of normal capillary refill times and a wide variation in elastic recoil, and no true range has been documented. Skin turgor and elastic recoil is, instead, classified into immediate, slightly delayed or prolonged. Several conditions may falsely normalise (obesity, hypernatraemia) or prolong (malnutrition) the recoil rate.

​

What about sunken eyes and dry mucous membranes?

They add very little to clinical reasoning, with a pooled positive likelihood ratio of only 1.7.

​

Was my mum right when she told me I had to drink water as my wee was too dark?

There is something in this not-so-old wive’s tale. U-osm increases in response to dehydration, but there is no international consensus for what U-osm cut-off indicates dehydration. Though 800 mOsm/kg seems to be used most often, be wary as this level may depend on other factors, including dietary intake. Urine colour has a strong relationship with urine osmolarity (Uosm). Urine colour has been validated as a biomarker for dehydration in adults and children over eight years of age. A bedside 8-point urine colour chart has been developed, and although it may detect dehydration it is not very specific for degree. Other urinary indices, such as specific gravity and urine ketone levels, show no correlation with the presence or absence of significant dehydration.

Some people have even tried serial use of a hand-held bladder scanner in place of bedside ultrasound to assess for urine production, but this has little utility in the real world.

So how do we know the percentage of dehydration?

Most studies use the percentage of body weight lost as the gold standard. Unless a child has been weighed recently, parents may be wildly inaccurate in their predictions. Researchers can categorise the percentage of dehydration by comparing their weight when they are well (in the post-illness phase) with their presenting weight.

per cent dehydration = baseline weight – admission weight) / baseline weight x 100

Experimental studies using radio-isotope labelled albumin have shown that percentage of body weight lost is directly comparable to the percentage of plasma volume lost.

​

Is it even clinically relevant?

Most studies regarding the assessment of dehydration have focused on diarrhoeal illness, but assessment and management of dehydration is also a cornerstone of managing diabetic ketoacidosis (DKA). In a small Australian study, there was little agreement between the assessed and measured degrees of dehydration. There was a tendency to overestimate dehydration in those less than 6% dehydrated with DKA and underestimate those with more than 6% fluid loss. Underestimation may lead to morbidity with an increased risk of overhydration and cerebral oedema.

​

With all of that in mind, what should you do?

No individual clinical sign can accurately predict the presence or the degree of dehydration. When used in combination, in the form of a dehydration scale, we are no closer to an answer. It seems that my gestalt is probably as accurate as any particular scale.

​
Read more about assessing dehydration in Andy Tagg's post here.

Stressed about Consultant Interview Prep? ​ I'm running a FREE LIVE TRAINING on Wednesday 25th October at 8pm (UK time). ​ 7 Steps To Ace Your Consultant Interview ​ Come and join us! YES! I WANT TO JOIN THE WEBINAR!

EVENT OF THE WEEK

Last week saw World Anaesthetics Day.

If you've ever been in a stressful intubation situation you will appreciate just how hard it can be.

Check out Vicki Currie's post on how to safely manage a challenging ED intubation here.

​

TIP OF THE WEEK

Diagnosing early sepsis is difficult.

It often presents non-specifically and can be accompanied by a distracting diagnosis.

"Could this be sepsis?" is worth asking yourself often.

Read more here.

​

JOKE OF THE WEEK

Why don't eggs tell jokes?

​

Because they might crack up!

​

That's it for this week, Reader.

​

Remember, your work makes a difference in the lives of paediatric patients every day.

​

Stay tuned for next week's edition of Bursting The Bubble.

​

From Tessa (on behalf of Team DFTB)

​

P.S. If you want to forward this email to someone who would enjoy the newsletter too, they can sign up here.

​

No longer interested in these emails? Click here to unsubscribe​