Asthma Exacerbations and Therapeutic Positioning

The idea: Sitting erect vs slouching or slumping improves airflow in moderate-severe exacerbations of asthma

A pale, breathless 7-year-old with a known history of asthma presents to your department. Oxygen saturations are hovering in the mid-’80s with marked tracheal tug, subcostal, substernal, intercostal and supraclavicular recessions in addition to accessory muscle usage. He’s moving air and there’s a widespread wheeze throughout the chest. This child has a moderate-severe exacerbation of asthma.

In addition to commencing standard management including O2, salbutamol, steroids, IV access for a VBG (and considering some MgSO4), you notice that he’s sliding down the bed and curling into a ball.

The Therapeutic Guidelines for Asthma Management recommend nursing the patient sitting upright, but this can be quite challenging, especially if the child keeps sliding down the bed.

Anecdotally, I’ve seen more than a dozen children in this setting whose SpO2 has improved in less than a minute after adequate re-positioning, in adjunct to standard management.

To ameliorate some of these challenges, it’s my practice to prop children in order to remain sitting upright. I was first taught some of these tips by Dr. Tom Hurley, Paediatrician on Queensland’s Sunshine Coast, and added a few of my own. I’ll describe my method for positioning a child upright (and getting them to stay there!) in the context of an exacerbation of asthma.

You will need:

• To first initiate standard management for asthma!
• A bed that sits up and has rails.
• 3-5 pillows/rolled up blankets or twice as many towels, rolled up.

What to do:

1. Tell the child and parent what you’re going to do, and why it’s helpful.
2. Make sure you can see as much of the anterior chest as dignified and practical; one of the main benefits of this positioning is that you can better observe the child’s work of breathing from the end of the bed.
3. Ramp up the head of the bed to being almost straight up; most beds will top out about 70 degrees, which will be sufficient.
4. Lift the child so their back is to the bed and their bottom is at the crease in the bed.
5. Place a blanket under their thighs as a wedge; this will stop them sliding down.
6. Additionally, if your supply of towels is plentiful, you can make a number of rolls side by side to the foot of the bed. This means the child can push on them with their feet.

1. Next, we want to prevent the child from slumping to either side.
2. Put up the rails and wedge the pillows next to the child’s torso, across the width of the bed. For smaller children, you can place the pillows flat, for larger kids you might need to place them on their edge. Either way, they shouldn’t be able to crumple off to one side if they get exhausted or fall asleep.

1. Additionally, if you still have spare pillows, you can position the pillows to stop the child’s head from rolling side to side.
2. Now, crack on with the rest of this child’s management!

Although I’m a bit uncertain on the science behind all this benefit, we’re taught in medical school about “tripoding”;  most of us are familiar with the ‘tripod prayer’ seen in adults with exacerbations of COPD. It’s just a theory, but I suspect that once in bed, children don’t adequately tripod.

Firstly, they just don’t know how to position themselves, either because breathlessness is a new sensation or they’re too young. Secondly, kids simply don’t have the levers to adequately tripod against their surroundings. Thirdly, once in a large hospital bed, the surroundings are soft and squishy, reducing the efficacy of uncoordinated tripoding. Fourthly, the improved PEFR in the erect vs supine position is well demonstrated in a number of experiments done in the 1960s and 1980s (see references). Lastly, the V/Q mismatch that occurs in asthma might further benefit from an upright position.

In the spirit of #FOAMPed, I thought I’d float this out there and see if anyone has other methods of optimizing positioning for these patients.

Selected references

Haffejee, I E., Effect of supine posture on peak expiratory flow rates in asthma. Arch Dis Child 1988 63: 127-129

Moreno F, Lyons HA. Effect of body posture on lung volumes. J Appl Physiol. 1961 Jan;16:27-9. https://www.ncbi.nlm.nih.gov/pubmed/13772524