• 
• 

Three Part Question

In [children in anaphylaxis] does [lying flat with feet elevated] help with [cardiovascular and respiratory symptoms]?

Clinical Scenario

A 10 year old child presents to the paediatric emergency department after eating peanut butter to which he is allergic. His reaction is severe, he is struggling to breathe and his blood pressure is low. IM adrenaline, steroids and fluids are administered. You wonder if lying the child flat will help his symptoms.

Search Strategy

Medline 1946 to June Week 1 2013
EMBASE 1980 to 2013 Week 26

‘((exp hypersensitivity/) OR (exp anaphylaxis/) OR (anaphyla$.mp) OR (aller$.mp) OR (acute ADJ allergic ADJ reaction)) AND ((exp supine position/) OR (exp posture/) OR (recline$.mp) OR (lying down.mp) OR (lying flat.mp)) LIMITS – English Language, Humans, Children (0-18 years)

Search Outcome

158 papers were found, only one was relevant

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Pumphrey, RSH 2003 UK	88 fatal anaphylactic shock patients	Retrospective autopsy report review	An upright posture can be fatal in anaphylaxis	In 4 patients death occurred in seconds after a movement to a more upright position In 1 patient death occurred after moving from a chair to a bed. In 5 patients had been supported in an upright position despite unconsciousness and subsequently died.	Only small number of patients have postural changes noted in reports. May have been other confounding factors, which lead to death.

Comment(s)

The findings of Pumphreys study fit with the known cardiovascular changes in anaphylaxis. Due to vasodilation and increased capillary permeability, blood volume is significantly decreased. Compensatory mechanisms may be able to maintain an adequate venous return in a supine position, but not when the patient is upright. Without adequate venous filling the left side of the heart will empty, leading to a lack coronary artery perfusion

Clinical Bottom Line

Although again more research is needed in this area, it seems sensible to opt for this simple maneourve for patients in anaphylactic shock.

References

1. Pumphrey RSH. Fatal posture in anaphylactic shock Journal of Allergy and Clinical Immunology. 2003;112(2):451-2.