Correspondence

Cardiac Resuscitation

N Engl J Med 2001; 345:546-547August 16, 2001

Article

To the Editor:

The review of cardiac resuscitation by Eisenberg and Mengert (April 26 issue)1 summarizes the 2000 guidelines of the American Heart Association and encouraging survival results from Seattle, but it fails to focus on the brain. Since encephalopathy can begin four minutes after the cessation of blood flow in normothermic persons,2 the artificial circulation of oxygenated blood must be initiated by a bystander within seconds of a collapse. Multifaceted, community-based self-training programs may be able to help.3

I disagree with the statement that “Decades of research have failed to find the means to improve brain resuscitation significantly.” Two interventions are effective. Hypertensive reperfusion2 has been shown to improve cerebral outcome in dogs 4 and was associated with better outcome in humans.5 Mild resuscitative hypothermia (33 to 36°C), induced as early as possible after hypertensive reperfusion and sustained for at least 12 hours, normalized cerebral outcome in dogs after 11 minutes without blood flow at normal temperature.2,6 Mild hypothermia, which is safer and simpler to induce than moderate hypothermia (28 to 32°C), was found in recent clinical feasibility trials in Europe, Australia, and Japan to be beneficial after cardiac arrest.

Peter Safar, M.D.
University of Pittsburgh, Pittsburgh, PA 15260
safarp@anes.upmc.edu

6 References

1. 1

   Eisenberg MS, Mengert TJ. Cardiac resuscitation. N Engl J Med 2001;344:1304-1313
   Full Text | Web of Science | Medline

2. 2

   Safar P. Resuscitation of the ischemic brain. In: Albin MS, ed. Textbook of neuroanesthesia with neurosurgical and neuroscience perspectives. New York: McGraw-Hill, 1997:557-93.
   

3. 3

   Eisenburger P, Safar P. Life supporting first aid training of the public -- review and recommendations. Resuscitation 1999;41:3-18
   CrossRef | Web of Science | Medline

4. 4

   Sterz F, Leonov Y, Safar P, Radovsky A, Tisherman S, Oku K. Hypertension with or without hemodilution after cardiac arrest in dogs. Stroke 1990;21:1178-1184
   CrossRef | Web of Science | Medline

5. 5

   Sasser HC, Safar P. Arterial hypertension after cardiac arrest is associated with good cerebral outcome in patients. Crit Care Med 1999;27:Suppl:A29-A29 abstract.
   CrossRef | Web of Science

6. 6

   Safar P, Xiao F, Radovsky A, et al. Improved cerebral resuscitation from cardiac arrest in dogs with mild hypothermia plus blood flow promotion. Stroke 1996;27:105-113
   CrossRef | Web of Science | Medline

To the Editor:

The review of cardiac arrest includes some unexplained information in Figure 1. Only 28 percent of the persons with unwitnessed cardiac arrests had ventricular fibrillation or ventricular tachycardia, but 65 percent of those whose arrests were witnessed by bystanders had ventricular fibrillation or ventricular tachycardia. What is the reason for the large difference between the two groups?

Richard H. Fine, M.D.
San Francisco General Hospital, San Francisco, CA 94110
rhfine@itsa.ucsf.edu

To the Editor:

Cardiopulmonary resuscitation is usually performed with the patient in a horizontal position. The compression of the chest results in forward blood flow, producing some cardiac output. However, what about the venous return? Sufficient venous return is essential for the restoration of efficient circulation. It is my impression that enhancement of venous return by placing the patient in Trendelenburg's position (with the legs in an upright position) before beginning thoracic compression increases the success rate. Trendelenburg's position produces blood return from the legs for sufficient blood volume during cardiac resuscitation.

Hans von Baeyer, M.D.
Dialysepraxis Tiergarten, D-10785 Berlin, Germany

Author/Editor Response

The authors reply:

To the Editor: We certainly agree with Dr. Safar that brain resuscitation is a critical consideration in cases in which cardiac resuscitation is required. Roughly 10 to 30 percent of survivors of cardiac arrest have brain injury.1,2 In one study of in-hospital cardiac arrests, approximately half the patients had moderate-to-severe neuropsychological sequelae within the first year after the arrest.3 Promising pharmacologic interventions involving the use of either nimodipine or magnesium have, unfortunately, not shown benefit in clinical trials. We are aware of promising results of induced cerebral hypothermia in cardiac arrest in dogs. Ongoing clinical trials may clarify the best way to optimize outcomes in terms of brain function. Unfortunately, a recent trial of induced hypothermia in patients with severe traumatic brain injury failed to show any benefit.4

Dr. Fine's observation that the rate of ventricular fibrillation or ventricular tachycardia among patients with witnessed arrests was higher than the rate among those with unwitnessed arrests is correct. This difference is presumably a consequence of the deterioration in the rhythm from ventricular fibrillation or ventricular tachycardia to asystole or a preterminal idioventricular or agonal rhythm after an unwitnessed cardiac arrest.

We think Dr. von Baeyer's suggestion that Trendelenburg's position be used during cardiopulmonary resuscitation is intriguing. We are not aware of any experimental data supporting or refuting the benefit of such a position during cardiac arrest. Although Trendelenburg's position would optimize venous return from the legs, it might impair venous return from the brain. What effect would impaired cerebral venous return have on cerebral resuscitation? These are questions in need of further study.

Mickey S. Eisenberg, M.D., Ph.D.
Terry J. Mengert, M.D.
University of Washington Medical Center, Seattle, WA 98195-6123
gingy@u.washington.edu

4 References

1. 1

   Robertson S, Safar P. Cardiopulmonary-cerebral resuscitation. In: Grenvik A, Ayers SM, Holbrook PR, Shoemaker WC, eds. Textbook of critical care. 4th ed. Philadelphia: W.B. Saunders, 2000:9-20.
   

2. 2

   Bergner L, Bergner M, Hallstrom A, Eisenberg M, Cobb LA. Health status of survivors of out-of-hospital cardiac arrest six months later. Am J Public Health 1984;74:508-510
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3. 3

   Roine RO, Kajaste S, Kaste M. Neuropsychological sequelae of cardiac arrest. JAMA 1993;269:237-242
   CrossRef | Web of Science | Medline

4. 4

   Clifton GL, Miller ER, Choi SC, et al. Lack of effect of induction of hypothermia after acute brain injury. N Engl J Med 2001;344:556-563
   Full Text | Web of Science | Medline

Citing Articles (9)

Citing Articles

1. 1

   Kenneth R. Diller, Liang Zhu. (2009) Hypothermia Therapy for Brain Injury. Annual Review of Biomedical Engineering 11:1, 135-162
   CrossRef

2. 2

   Heleen den Hertog, Bart van der Worp, Maarten van Gemert, Diederik Dippel. (2007) Therapeutic hypothermia in acute ischemic stroke. Expert Review of Neurotherapeutics 7:2, 155-164
   CrossRef

3. 3

   Donald W. Marion. (2004) Controlled normothermia in neurologic intensive care. Critical Care Medicine 32:Supplement, S43-S45
   CrossRef

4. 4

   Harald G. Fritz, Reinhard Bauer. (2004) Secondary Injuries in Brain Trauma: Effects of Hypothermia. Journal of Neurosurgical Anesthesiology 16:1, 43-52
   CrossRef

5. 5

   Ludger Bahlmann, Stefan Klaus, Wolfgang Baumeier, Peter Schmucker, Claus Raedler, Christian A. Schmittinger, Volker Wenzel, Wolfgang Voelckel, Karl H. Lindner. (2003) Brain metabolism during cardiopulmonary resuscitation assessed with microdialysis. Resuscitation 59:2, 255-260
   CrossRef

6. 6

   Hülya Bayr, Robert S. B. Clark, Patrick M. Kochanek. (2003) Promising strategies to minimize secondary brain injury after head trauma. Critical Care Medicine 31:Supplement, S112-S117
   CrossRef

7. 7

   T. Frietsch, A. Piepgras, P. Krafft, S. Schwab, W. Kuschinsky, K. F. Waschke. (2002) Acid-base management - is it relevant for the study design of hypothermic neuroprotection?. European Journal of Anaesthesiology 19:6, 389-394
   CrossRef

8. 8

   The Hypothermia after Cardiac Arrest Study Group. (2002) Mild Therapeutic Hypothermia to Improve the Neurologic Outcome after Cardiac Arrest. New England Journal of Medicine 346:8, 549-556
   Full Text

9. 9

   Myron D. Ginsberg. (2002) Therapeutic trials for traumatic brain injury???A journey in progress *. Critical Care Medicine 30:4, 935
   CrossRef