This study systematically reports the relative and absolute chest compression depths delivered to older children, adolescent and young adult patients during actual CPR guided by pediatric ICU and ED providers. After compensating for mattress compression, 92.2% of CCs delivered to in-hospital cardiac arrest victims 8–14 years were less than 1/3 AP chest depth (the minimum pediatric CC recommendation at the time of data collection). In addition, 59.8% of the pre-puberty events had mean corrected CC depth of less than 38 mm (the minimum adult CC recommendation at the time of data collection).
In a study previously published by our research group, we reported the quantitative assessment of chest compression quality including a small number of the same events from this study. However, a number of important differences exist between the 2009 report and this study. Specifically, a completely different analysis approach was taken for this study in order to report mattress compensated depth, percent AP compression depth and the 2010 (not available in 2009) AHA Guidelines. In addition, the 2009 report analyzed and divided the data into 30 sec segments of actual measured chest compression without mattress compensation. In this report, we determined average corrected compression depth per patient for process of care outcomes (compliance with AHA Guidelines) against both the 2005 and 2010 AHA Guidelines.
Unlike evidence-based CC depth recommendations for adults, specific evidence for target depth of CC in children is lacking; thus, therapeutic targets for pediatric CCs have been based on expert consensus. As an example, a CC depth relative to the anterior–posterior chest depth (% APD), rather than an absolute depth, was previously recommended for children in order to encourage deeper CCs. This recommendation, however, was not based on real pediatric CPR, hemodynamic, or outcome data. In 2010, the AHA guidelines, ERC guidelines, and ILCOR consensus on science with treatment recommendations for pediatrics were updated, in order to encourage rescuers to provide adequately deep CCs. Conversely, these guidelines were developed from knowledge extrapolated from adult CC data, animal models, CT measurements of chest depth, and descriptive data of reported continued delivery of shallow CCs by rescuers.4,5,8,12,18
After utilizing a mattress correction analysis,16
we calculated relative and absolute CC depth and compared our findings to previous (2005) and current (2010) adult and pediatric CC depth recommendations. From our results, a CC depth of 38–51 mm corresponds to 22–29% APD in these patients 8–22 years of age receiving in-hospital CPR. However, when stratified by age, 38–51 mm corresponds to 24–32% APD for these 8–14 year olds, and 20–27% APD for these subjects 15 years or above. Pickard et al.19
found that the external compression depth target for adults, 38–51 mm, corresponded to ~6–20% APD for their cohort of male adults and 17–21% for their cohort of female adults. It would appear from these data that an increase in absolute CC depth targets may be warranted in order to achieve a greater APD percentage which may elicit improved hemodynamics.5,18,20–23
Several studies of in-hospital and out-of-hospital CPR support current AHA emphasis on adequately deep CCs, by linking quality of CPR measures with patient survival outcomes.4,5,7,8
In an attempt to improve adherence to expert guideline recommendations, quantitative CPR quality monitoring systems have been developed and utilized during adult resuscitation attempts. Real-time audiovisual directive and corrective CPR feedback can improve adherence to guidelines and resuscitation outcomes.20
These systems utilize force transducer and accelerometer technology and are able to determine chest deflection (mm) during a given CC. Extension of this real-time audiovisual CPR feedback technology, which relies on absolute depth measurements, to provide feedback to younger subjects requires determination of reasonable target depths for those children, and may require compensation for soft hospital beds. In our study population of 8–14 year olds, using 2005 adult guidelines of 38–51 mm, healthcare providers only delivered minimally guideline compliant CC depth 59% of the time, equivalent to 22 ± 4% APD. Looking toward the new 2010 guidelines in our pre-pubertal population (8–14 years), a CC of 50 mm would compress 38% (6/16) of the subject chests to >1/3 APD but would not reach 1/2 APD in any of the subjects. A 50 mm CC would compress to a mean 31% APD. Consequently, the use of a constant CC depth target of 50 mm may not be harmful for this pediatric pre-pubescent (8–14 year old) population, however this study does not directly address the harm/safety of this practice.
Greater compliance with CPR guidelines has previously been associated with better outcomes in other settings.6–8
This study was not intended, nor powered, to associate depth of chest compression with outcome. In this selected population, average event corrected CC depth <38 mm vs. ≥38 mm was not statistically associated with a difference in ROSC or survival to hospital discharge, but the power to detect a difference was very low (p
= 1.0). Additional multi-center investigation with appropriate power should be completed to properly correlate the significance of CC depth with ROSC and mortality.
Studies of adult CPR demonstrate that even with real-time audiovisual directive and corrective CPR feedback, rescuers will ignore automated feedback prompts for deeper compressions when they subjectively feel that they have provided adequate force.24
Rescuer fear of doing harm to the patient by delivering a CC that may ultimately be harmful is an ongoing issue and barrier to providing adequately deep CCs in all age groups. In our study, the mean compression force applied for the pre-puberty and post-puberty groups (30.7 kg ± 7.6 kg, 33.6 ± 9.4 kg, p
= 0.07) was about the same as reported by Tomlinson et al. in their older adult population (median age 70 [IQR 61, 81]; mean force applied was 30.3 ± 8.2 kg)24
yet was lower than the mean 43.9 ± 4.0 kg as reported in the adult study (age range 25–76 years) by Gruben et al.25
Maltese et al.’s study of the 8+ year old population (age range 8–22 years) demonstrated a comparable mean compression force of 30.9 ± 5.5 kg.14
Interestingly, they noted that when plotting the stiffness of the chest with the adult data collected by Tsitlik et al.26
, the stiffness of the chest appears to increase from youth to middle age and then decrease in the elderly. The corresponding compression force required to reach a uniform compression depth across age would follow the same pattern. Evidence from a systematic review of pediatric CPR showed that rib fractures are rarely associated with CCs27
suggesting that a deeper CC may be provided to the younger children without causing the minor injuries seen more frequently in the adult population.
The 2010 ILCOR consensus on science and 2010 AHA guidelines now recommend both absolute and relative APD CC depth targets in order to encourage improved depth of CC. Our data suggests that informed and experienced pediatric health care providers in tertiary care children’s hospitals are not currently routinely achieving the recommended relative CC depth targets nor the actual CC depth targets in clinical practice. We speculate that the extension of reliable real-time audiovisual CPR feedback technology with actual depth measurements might facilitate code leader direction to have the team achieve deeper compressions for children of all ages.