Reply to: Intraosseous Versus Intravenous Resuscitation During In-Hospital Cardiac Arrest

Abstract

15 jection" used in the primary aim statement of our Introduction. By this 16 we mean generally "injection of medications" through either a 17 peripheral intravenous (PIV) or intraosseous (IO) device during car-18 diac arrest. We provide data only on epinephrine administration as 19 this is the most consistently used medication during cardiac arrest. 20 Additional medications were given to patients in this study with some 21 frequency. However, information regarding their relative use was 22 incomplete. Given this incomplete documentation, in combination 23 with their mostly undetermined or neutral effects on our study out-24 comes, we felt their comparative utilization would be difficult to inter-25 pret in the context of our study. 1 26 Second, we are asked to clarify the patient population in our 27 study. We use the term "acute care" to mean all those on the hos-28 pital floor, step-down unit (i.e. intermediate severity of illness 29 between ICU and floor), and observation unit (e.g. those patients 30 expected to stay inpatient for <72 hrs). As such, when included with 31 the intensive care and procedural patients, we feel our study popula-32 tion reasonably includes those thought of as being "in-hospital." 33 Third, we are asked to differentiate between those patients in the 34 "PIV group" who had pre-existing PIV access and those who had 35 PIV placed after IHCA. Patients with pre-existing PIV access could 36 have shorter times-to-epinephrine (TTE) and shorter times-to-ROSC 37 (TTR). Differentiating between these groups may also more accu-38 rately reflect the entirety of the in-hospital resuscitation process. 39 The authors additionally request information regarding time-to-40 access between PIV and IO. Unfortunately, this information was 41 not available with robust presence in our dataset. As a surrogate 42 for venous access times, we used TTE. This variable has been asso-43 ciated with differences in survival and neurologic outcomes. 2,3 As 44 discussed in our paper, the TTE was statistically longer in the IO 45 group compared to the PIV population and we adjusted for this vari-46 able during multivariate logistic regression.47 65 is a statistically significant difference in the number of witnessed car-66 diac arrest events between the PIV and IO group in favor of the PIV 67 group. In fact, several studies have shown an association between 68 witnessed status and increased odds of survival during IHCA. 5 Thus, 69 having a higher percentage of witnessed events in the PIV group 70 may skew towards more favourable outcomes. We have attempted 71 to correct for such a difference by adjusting for this variable using 72 multivariate logistic regression, rather than performing a subgroup 73 analysis as suggested. 6,7 74 Many of the limitations addressed here and previously should be 75 considered when interpreting the outcomes of our paper. Neverthe-76 less, we feel our analysis serves to add meaningful knowledge to 77 IHCA resuscitation literature, in addition to serving as a basis for fur-78 ther prospective ...