Exertional Heat Injury with Harvey Pynn

In this session we will examine Exertional Heat Injury (EHI)
within individuals undertaking endurance races, military
exercises, or extreme activity. We will draw contrast and
parallels to acute behavioural disturbance, what is happening
both at the physiological level and some of the autonomic
positive feedback mechanisms within EHI. To do this I have
Harvey Pynn with me, Harvey is a Lieutenant colonel within the
British Military and an Emergency Medicine and air ambulance
consultant with GWAAC. In the episode we examine: 


·  Definitions, spectrum of disease – EHI as a broad
definition and spectrum of states


·  How are thinking has changed on heat illness and what is
happening on a physiological level


·  Incidence of EHI; anecdotal and empirical


·  The hierarchy of ‘exercise-state’ heat loss –
evaporative, convective, conduction, then radiation.


·  Heat acclimatisation: Salt concentration (aldosterone
mediated), sweating initiation and rate.


·  Risk factors (individual, environmental)- concomitant
disease or drugs (dehydration, alcohol, co-morbid disease,
medication)


·  Subtle and not so subtle prodromal signs and symptoms of
heat injury & why urine colour isn’t a great marker (lack of
micturition during     dehydration).


·  Preventative measures and treatment modalities in severe
EHI 


·  Analogues of comparison and symptomatology – ABD, drug
induced hyperthermia.


·  Differential diagnosis and an anecdotal case from
Harvey 





Please find some related research produced by Harvey pertaining
to measuring dehydration and the sequlae of EHI:


https://www.researchgate.net/publication/327822126_The_Compensatory_Reserve_Index-potential_uses_in_a_military_context





Please also see relevant empirical literature that is congruent
with the podcast:


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819979/





Please enjoy this episode with an engaging and informative
guest.