Correspondence

Cardiopulmonary Resuscitation in Children

N Engl J Med 1997; 336:1325-1326May 1, 1997

Article

To the Editor:

Schindler et al. (Nov. 14 issue)1 report the clinical predictors of unsuccessful resuscitation in children who had out-of-hospital cardiac or respiratory arrest. Among the predictors of unsuccessful resuscitation identified in the study was the requirement for higher doses of sodium bicarbonate during resuscitation in the emergency department. Before any conclusions can be made about the variables influencing the decision to stop efforts at resuscitation, this observation should be carefully examined.

Most studies have failed to demonstrate that the administration of sodium bicarbonate in the course of cardiopulmonary resuscitation improves the outcome of cardiac arrest in children.2,3 Instead, a growing body of evidence suggests that the administration of bicarbonate may not be beneficial and may actually be detrimental.

Cardiopulmonary arrest in children, as opposed to adults, is rarely an acute, primary cardiac event. Instead, it is often the terminal event in a progressive deterioration of respiratory or circulatory function,2 as clearly reflected by the characteristics of the patients in the study by Schindler et al. and the initial blood gas values in the emergency department. Since bicarbonate therapy transiently elevates carbon dioxide tension, its administration during resuscitation in children may actually worsen preexisting respiratory acidosis.4 The additional carbon dioxide generated by the administration of bicarbonate readily diffuses into cells and produces intramyocardial and intracerebral acidosis. This effect ultimately leads to the depression of both myocardial and cerebral function.5

The treatment of arrest-induced acidosis remains controversial. The mainstay of therapy consists of efforts to maximize oxygenation and tissue perfusion. Bicarbonate is not a first-line drug; its use should be considered if there is no response to advanced life-support efforts.2 Injudicious use of sodium bicarbonate can potentially reduce the effectiveness of cerebral–cardiopulmonary resuscitation in children.

With these points in mind, the observation that the children who did not survive had been given more sodium bicarbonate than those who survived may reflect not merely more intensive and vigorous resuscitation efforts, as the writers imply, but inappropriate use of this agent.

Oren Fruchter, M.D.
29 Greenbaum St., Haifa 34987, Israel

5 References

1. 1

   Schindler MB, Bohn D, Cox PN, et al. Outcome of out-of-hospital cardiac or respiratory arrest in children. N Engl J Med 1996;335:1473-1479
   Full Text | Web of Science | Medline

2. 2

   Emergency Cardiac Care Committee and Subcommittees, American Heart Association. Guidelines for cardiopulmonary resuscitation and emergency cardiac care. VI. Pediatric advanced life support. JAMA 1992;268:2262-2275
   CrossRef | Web of Science

3. 3

   Zaritsky A. Pediatric resuscitation pharmacology. Ann Emerg Med 1993;22:445-455
   CrossRef | Web of Science | Medline

4. 4

   Gazmuri RJ, von Planta M, Weil MH, Rackow EC. Cardiac effects of carbon dioxide-consuming and carbon dioxide-generating buffers during cardiopulmonary resuscitation. J Am Coll Cardiol 1990;15:482-490
   CrossRef | Web of Science | Medline

5. 5

   Weisfeldt ML, Guerci AD. Sodium bicarbonate in CPR. JAMA 1991;266:2129-2130
   CrossRef | Web of Science | Medline

Author/Editor Response

The authors reply:

To the Editor: The use of bicarbonate therapy during cardiopulmonary resuscitation in children continues to be controversial. Although we realize that there is a theoretical concern about the effect of the increase in carbon dioxide production associated with bicarbonate therapy, we would like to make the following observations. There is uniform agreement that positive-pressure ventilation and the administration of epinephrine, not bicarbonate, are the first-line therapies for cardiac arrest in children. In our study, all the patients had out-of-hospital cardiopulmonary arrest, and global hypoxic ischemia was therefore prolonged. Under these circumstances, there is severe metabolic acidosis, for which bicarbonate therapy may be effective. Bicarbonate was used after chest compressions, epinephrine, and ventilation had failed to restore spontaneous circulation.

In the absence of underlying heart disease, cardiac arrest in children is primarily due to hypoxia, which must be prolonged to cause the cessation of cardiac activity. In a study of brain-dead children in whom ventilator support was being withdrawn, the mean interval between apnea and asystole was 17 minutes.1 Thus, asystolic cardiac arrest in children is associated with prolonged cerebral hypoxia, and the resultant injury is unlikely to be influenced by whether or not bicarbonate therapy is used. This view is supported by Kurose et al.,2 who found that hypoxia during cardiopulmonary resuscitation, not pH or bicarbonate therapy, was correlated with severe cerebral dysfunction in adults.

In terms of studies of bicarbonate therapy during cardiopulmonary resuscitation in humans, we are aware of only one randomized trial. This study, which involved adults who had had an out-of-hospital cardiac arrest, showed no difference in the rates of admission or survival to discharge in the two groups.3 There have been no similar studies in children. One well-controlled study by Vukmir et al.4 showed that the use of bicarbonate therapy in dogs, which were maintained in arrest for 15 minutes before resuscitation, was associated with improvement in the return of spontaneous circulation, survival at 24 hours, and the neurologic outcome.

Thus, in the absence of any convincing studies in children, we believe there is a place for bicarbonate therapy in the management of prolonged hypoxic arrest in children if the establishment of effective ventilation and the administration of epinephrine have failed to restore spontaneous circulation.

Margrid Schindler, M.B., B.S.
Great Ormond Street Hospital for Children, London WC1N 3JH, United Kingdom

Desmond Bohn, M.B., B.Ch.
John Edmonds, M.B., B.S.
Hospital for Sick Children, Toronto, ON M5G 1X8, Canada

4 References

1. 1

   Friesen RM, Duncan P, Tweed WA, Bristow G. Appraisal of pediatric cardiopulmonary resuscitation. Can Med Assoc J 1982;126:1055-1058
   Web of Science | Medline

2. 2

   Kurose M, Okamoto K, Sato T, et al. The determinant of severe cerebral dysfunction in patients undergoing emergency extracorporeal life support following cardiopulmonary resuscitation. Resuscitation 1995;30:15-20
   CrossRef | Web of Science | Medline

3. 3

   Dybvik T, Strand T, Steen PA. Buffer therapy during out-of-hospital cardiopulmonary resuscitation. Resuscitation 1995;29:89-95
   CrossRef | Web of Science | Medline

4. 4

   Vukmir RB, Bircher NG, Radovsky A, Safar P. Sodium bicarbonate may improve outcome in dogs with brief or prolonged cardiac arrest. Crit Care Med 1995;23:515-522
   CrossRef | Web of Science | Medline

Citing Articles (1)

Citing Articles

1. 1

   Gad Bar-Joseph. (1999) The use of acid buffers during cardiopulmonary resuscitation: a time to change again?. Current Opinion in Critical Care 5:3, 201
   CrossRef