RT Book, Section
A1 Zafren, Ken
A1 Thurman, R. Jason
A1 Jones, Ian D.
A2 Knoop, Kevin J.
A2 Stack, Lawrence B.
A2 Storrow, Alan B.
A2 Thurman, R. Jason
SR Print(0)
ID 1181050813
T1 Hypothermia
T2 The Atlas of Emergency Medicine, 5e
YR 2021
FD 2021
PB McGraw-Hill
PP New York, NY
SN 9781260134940
LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1181050813
RD 2024/04/24
AB Accidental  hypothermia  is  an  unintentional  decline  in  core  temperature  below  35°C  (95°F).  Presentation  may  be  obvious  or  subtle,  especially  in  urban  settings.  Symptoms  vary  from  vague  complaints  to  altered  levels  of  consciousness.  Physical  findings  include  progressive  abnormalities  of  every  organ  system.  Following  initial  tachycardia,  there  is  progressive  bradycardia  (50%  decrease  in  heart  rate  at  28°C  [82.4°F])  with  decline  in  blood  pressure  and  cardiac  output.  Electrocardiogram  (ECG)  intervals  are  prolonged,  beginning  with  the  PR  interval  followed  by  the  QRS  interval  and  finally  the  QT  interval.  A  J  wave  (Osborn  wave;  hypothermic  “hump”)  may  be  seen,  but  is  neither  pathognomonic  nor  prognostic.  The  J  wave  is  present  at  the  junction  of  the  QRS  complex  and  the  ST  segment.  J  waves  may  also  be  associated  with  central  nervous  system  lesions,  focal  cardiac  ischemia,  young  age,  and  sepsis.  In  mildly  hypothermic  patients,  an  invisible  increase  in  preshivering  muscle  tone  may  obscure  P  waves.