Optimizing chest compression to rescue ventilation ratios during one-rescuer CPR by professionals and lay persons: children are not just little adults.
OBJECTIVE
To estimate the optimum ratio of chest compressions to ventilations for one-rescuer CPR that maximizes systemic oxygen delivery in children.


METHODS
Equations describing oxygen delivery and blood flow during CPR as functions of the number of compressions and the number of ventilations delivered over time were adapted from the former work of Babbs and Kern. These equations were solved explicitly as a function of body weight, using scaling algorithms based upon principles of developmental anatomy and physiology.


RESULTS
The optimal compression to ventilation (C/V) ratios for infants and younger children increase sharply as a function of body weight. Optimal C/V ratios are lower for professional rescuers, who take less time to deliver a rescue breath, than for lay rescuers, who interrupt chest compressions for longer to perform ventilations. For professional rescuers the optimal C/V ratio, x*, is approximately 1.6 square root W where the W is the patient's body weight in kg. For lay rescuers the optimum C/V ratio is approximately 2.8 square root W. These values can be approximated for children and teens by the following rules of thumb, based upon the age of the victim: "5 + one half the age in years" for professional rescuers and "5 + age in years" for lay rescuers.


CONCLUSIONS
Compression to ventilation ratios in CPR should be smaller for children than for adults and gradually increase as a function of body weight. Optimal CPR in children requires relatively more ventilation than optimal CPR in adults. A universal compression/ventilation ratio of 50:2, targeted to optimize adult resuscitation, would not be appropriate for infants and young children.
Babbs
Charles F
CF
Department of Basic Medical Sciences, Purdue University, and Indiana University School of Medicine, 1246 Lynn Hall, West Lafayette, IN 47907-1246, USA. babbs@purdue.edu
Nadkarni
Vinay
V
D000328:Adult; D000367:Age Factors; D001784:Blood Gas Analysis; D001823:Body Composition; D001835:Body Weight; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D002675:Child, Preschool; D005260:Female; D006282:Health Personnel; D006336:Heart Massage / Q000379:methods*; D006801:Humans; D007223:Infant; D008297:Male; D008348:Manikins; D008962:Models, Theoretical; D011312:Pressure; D011361:Professional Competence; D015656:Respiratory Mechanics; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013909:Thorax; D013990:Tidal Volume; D014692:Ventilation-Perfusion Ratio