Response to Letter: Increased incidence of CPR-related rib fractures in infants – Is it related to changes in CPR technique?

Abstract

Sir, We appreciate the Letter to the Editor by Martin et al., 1 and welcome the opportunity to respond. Identification of the study population was based upon the cause of the fractures, as determined from autopsy findings and information gathered by the Coroner and police investigators. None of the study cases had a history of accidental trauma; nor was there any circumstantial or pathological evidence of inflicted trauma/abuse. Incidences of acute posterior segment rib fractures were not identified. Microscopic examination confirmed the lack of a cellular inflammatory reaction at the fracture site, in keeping with an immediate peri-mortem event. Our cohort did include two infants (Case #8 and #12) who were born prematurely (25 and 32 weeks gestational age, respectively). Case #8 died in hospital at the corrected age of 32 weeks and case #12 died at home at 20 weeks of age. We do recognize that premature neonates are at an increased risk for sustaining rib fractures, 2 but do not feel it warranted their exclusion from the study population. Regarding Case #9, although this infant was clinically suspected to have birth-related trauma, death was in fact due to a Group B Streptococcus infection. All of the postmortem examinations were performed under the direct supervision of experienced pediatric pathologists, following a standard protocol that did not materially change during the study period. Cases suspected to have rib fractures were photographed in situ at the time of autopsy, with documentation of the number and location of the fractures and extent of soft tissue haemorrhage. The involved area of the rib cage was excised, radiologically imaged and the suspected fracture sites histologically analysed to confirm the fracture diagnosis. With respect to the CPR technique, we surmised that the “twothumbs encircling hands” (TT) method was used in the cases from 2006 to 2008 because the 2005 ILCOR update advocated its use by healthcare providers 3 and all the infants in our study had resuscitation performed in a medical setting. We fully accept some of the cases of acute rib fractures in the 2006–2008 period may have occurred in the setting of the “two-finger” (TF) compression method, which may also be associated with rib fracturing as indicated by our finding of five cases of acute CPR-related rib fractures during the 1997–2005 period when TF compression was the recommended technique. Nevertheless, we believe the difference in the incidence of acute rib fractures before and after the published change in CPR technique is so striking that it was reasonable to postulate the difference was related to greater bending forces being applied to the ribs via the TT method. 4 Further research into the relationship between the method of cardiac compressions in infants and the risk of rib fracturing is clearly indicated. 5 Regardless of the underlying explanation for the recent increase in CPR-related rib fractures, we maintain that this observation remains an important consideration when both clinicians and pathologists encounter acute rib fractures in infants who have undergone cardiopulmonary resuscitation.