Page 270 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

174 PART 2: General Management of the Patient

the use of cardiac arrest treatment can be judiciously tailored to the CHAPTER Therapeutic Hypothermia
appropriate patients. Physicians must emphasize the distinction to
76
patients between DNR and comfort care. That is, a DNR order means
that all curative measures could be employed except chest compressions 26 Benjamin S. Abella
and defibrillation. This distinction is also important for hospital person- Marion Leary
nel and physicians to understand, lest a DNR order influence other care
decisions in the critically ill. In short, do not resuscitate should never
mean do not treat. 77 KEY POINTS

• Induced hypothermia has been shown to reduce mortality when
applied after resuscitation from cardiac arrest.
KEY REFERENCES • Current guidelines recommend induced hypothermia for out-of-
• Abella BS, Alvarado JP, Myklebust H, et al.Quality of cardiopul- hospital cardiac arrest (OHCA) shockable rhythms and suggest con-
monary resuscitation during in-hospital cardiac arrest. JAMA. sideration of induced hypothermia for OHCA nonshockable rhythms
January 19, 2005;293(3):305-310. and in-hospital patients.
• Bobrow BJ, Clark LL, Ewy GA, et al. Minimally interrupted cardiac • In unconscious adults after out-of-hospital cardiac arrest, mild hypo-
resuscitation by emergency medical services for out-of-hospital thermia (36°C) appears to be as effective as more extreme hypother-
cardiac arrest. JAMA. March 12, 2008;299(10):1158-1165. mia (33°C) with regard to survival and neurological function.
• Edelson DP, Abella BS, Kramer-Johansen J, et al. Effects of compres- • Induced hypothermia may have benefit for other disease processes
sion depth and pre-shock pauses predict defibrillation failure dur- such as myocardial infarction and stroke.
ing cardiac arrest. Resuscitation. November 2006;71(2):137-145. • The mechanisms by which hypothermia acts are multifaceted and
Epub 2006 Sep 18.56. Caffrey SL, Willoughby PJ, Pepe PE, Becker a focus of much current investigation.
LB. Public use of automated external defibrillators. N Engl J Med.
2002;347:1242.
• Fagnoul D, Combes A, De Backer D. Extracorporeal cardiopul- The notion of cooling patients for medical benefit is quite old. In
monary resuscitation. Curr Opin Crit Care. 2014;20(3):259-265. 1814, Baron Larrey, a French surgeon in the service of Napoleon’s
• Hazinski MF, Nolan JP, Billi JE, et al. Part 1: Executive summary: army, reflected on soldiers who suffered major injuries on the frozen
2010 International Consensus on Cardiopulmonary Resuscitation battlefields in Russia by commenting that “cold acts on the living parts …
and Emergency Cardiovascular Care Science With Treatment the parts may remain … in a state of asphyxia without losing their life.”
1
Recommendations. Circulation. October 19, 2010;122(16 suppl 2): A belated resurgence of interest in hypothermia has taken place in the
S250-S275. past decade, expanding the possible medical indications for its use.
• Neumar RW, Otto CW, Link MS, et al. Part 8: adult advanced cardio- Induced hypothermia, the intentional lowering of body temperature,
vascular life support: 2010 American Heart Association Guidelines has been explored in a number of acute critical care settings, including
myocardial infarction, stroke, head trauma, and after cardiac arrest.
for Cardiopulmonary Resuscitation and Emergency Cardio vascular
Care. Circulation. November 2, 2010;122(18 suppl 3):S729-S767. While the optimal depth and timing of hypothermia are not yet estab-
lished for these uses, most experts advocate a temperature goal of 32°C
doi: 10.1161/CIRCULATIONAHA.110.970988. Review. Erratum
in: Circulation. 2011 Feb 15;123(6):e236. to 34°C because it seems to provide significant benefit while avoiding
most of the adverse effects associated with the intervention. Timing of
• Peberdy MA, Callaway CW, Neumar RW, et al. Part 9: Post–Cardiac hypothermia, with respect to both time of induction and duration of
Arrest Care: 2010 American Heart Association Guidelines for therapy, is even more uncertain, although general consensus holds that
Cardiopulmonary Resuscitation and Emergency Cardiovascular cooling should be initiated as soon as possible after the morbid event
Care. Circulation. 2010;122:S768-S786. and should be maintained for at least 12 to 24 hours. Regarding specific
• Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and uses, there is particularly good evidence that hypothermia is protective
stroke statistics–2012 update: a report from the American Heart for the resuscitated cardiac arrest patient after return of spontaneous
2,3
Association. Circulation. January 3, 2012;125(1):e2-e220. Epub circulation (ROSC). The use of hypothermia in other clinical scenarios
2011 Dec 15. remains promising but less clear at present.
This chapter addresses elements of the history of hypothermia, the
• Stiell IG, Hebert PC, Wells GA, et al. Vasopressin versus epineph- laboratory and clinical data that have developed our understanding of its
rine for inhospital cardiac arrest: a randomised, controlled trial.
Lancet. 2001;358:105. use, some of the various techniques used to cool patients, and the clinical
syndromes for which hypothermia appears to offer the greatest advantage.
• Sutton RM, Friess SH, Maltese MR, et al. Hemodynamic-directed
cardiopulmonary resuscitation during in-hospital cardiac arrest.
Resuscitation 2014;85(8):983-986; epub PMID 24783998. HISTORY OF INDUCED HYPOTHERMIA
• Weisfeldt ML, Becker LB. Resuscitation after cardiac arrest: a The protective effects of hypothermia induction have been suggested
three-phase time-sensitive model. JAMA. 2002;288:3035. since the time of Hippocrates, who advocated packing bleeding patients
4
• Wik L, Kramer-Johansen J, Myklebust H, et al. Quality of cardio- in snow. Hypothermic protection was also noted by Napoleon’s
pulmonary resuscitation during out-of-hospital cardiac arrest. battlefield surgeon, Baron Larrey, during the French invasion of Russia.
JAMA. January 19, 2005;293(3):299-304. He observed improved survival of injured soldiers left in the snow
compared with those treated with warm blankets and heated drinks.
1
Induced hypothermia has been studied in a wide variety of illnesses, both
ischemic and nonischemic in nature (reviewed in refs. 5 through 7).
11
REFERENCES These include traumatic brain injury, 8-10 status epilepticus, arrhyth-
mia, sepsis, and the ischemic illnesses of myocardial infarction, stroke,
7,12
Complete references available online at www.mhprofessional.com/hall and cardiac arrest. Interestingly, the first reported use of induced

section02.indd 174 1/13/2015 2:05:13 PM