Successful Resuscitation in a Model of Asphyxia and Hemorrhage to Test Different Volume Resuscitation Strategies. A Study in Newborn Piglets After Transition

Abstract

Background: Evidence for recommendations on the use of volume expansion during cardiopulmonary resuscitation in newborn infants is limited.Objectives: To develop a newborn piglet model with asphyxia, hemorrhage, and cardiac arrest to test different volume resuscitation on return of spontaneous circulation (ROSC). We hypothesized that immediate red cell transfusion reduces time to ROSC as compared to the use of an isotonic crystalloid fluid.Methods: Forty-four anaesthetized and intubated newborn piglets [age 32 h (12–44 h), weight 1,220 g (1,060–1,495g), Median (IQR)] were exposed to hypoxia and blood loss until asystole occurred. At this point they were randomized into two groups: (1) Crystalloid group: receiving isotonic sodium chloride (n = 22). (2) Early transfusion group: receiving blood transfusion (n = 22). In all other ways the piglets were resuscitated according to ILCOR 2015 guidelines [including respiratory support, chest compressions (CC) and epinephrine use]. One hour after ROSC piglets from the crystalloid group were randomized in two sub-groups: late blood transfusion and infusion of isotonic sodium chloride to investigate the effects of a late transfusion on hemodynamic parameters.Results: All animals achieved ROSC. Comparing the crystalloid to early blood transfusion group blood loss was 30.7 ml/kg (22.3–39.6 ml/kg) vs. 34.6 ml/kg (25.2–44.7 ml/kg), Median (IQR). Eleven subjects did not receive volume expansion as ROSC occurred rapidly. Thirty-three animals received volume expansion (16 vs. 17 in the crystalloid vs. early transfusion group). 14.1% vs. 10.5% of previously extracted blood volume in the crystalloid vs. early transfusion group was infused before ROSC. There was no significant difference in time to ROSC between groups [crystalloid group: 164 s (129–198 s), early transfusion group: 163 s (162–199 s), Median (IQR)] with no difference in epinephrine use.Conclusions: Early blood transfusion compared to crystalloid did not reduce time to ROSC, although our model included only a moderate degree of hemorrhage and ROSC occurred early in 11 subjects before any volume resuscitation occurred.

Transthoracic Echocardiography of the Neonatal Laboratory Piglet

“…Other studies have shown that TTE can also be done in the right lateral, supine position as well as in the left lateral, half supine position (6, 26). Unfortunately, we were unable to assess positioning to access standard planes, because the protocol of the main study allowed supine position only (2). An additional limitation was that TTE was only performed on one piglet race using only one ultrasound probe.…”

“…In the present study we performed transthoracic echocardiography in newborn piglets before, during and after asphyxia and hemorrhage. A detailed description on instrumentation/procedures is available in the original publication (2). Briefly, in this, forty-four anesthetized and intubated newborn piglets [crossing of pietrain and landrace; age 32 h (12–44 h), weight 1,220 g (1,060–1,495g,), median (IQR)] were exposed to standardized hypoxia and blood loss until asystole occurred.…”

“…Invasive continuous monitoring of pressures is commonly used. Catheters can easily insert through the femoral vessels to measure arterial blood pressure or central venous pressure (2). The so-called Millar catheter is available in different versions and is being used for different applications.…”

Lung injury after asphyxia and hemorrhagic shock in newborn piglets: Analysis of structural and inflammatory changes

“…The animal procedure was approved by the responsible government authority (Regierungspräsidium Tübingen, Germany; TV-No:1262 and 1320) in accordance with the guidelines of the Federation of European Laboratory Animal Science Association (FELASA). A detailed description of the animal experiment is already published in Mendler, et al (2018) [12].…”

“…The present investigation aimed to carve out the effect of different volume replacement regimes on lung damage after asphyxia with blood loss. Successful resuscitation was achieved in all animals independent of group assignment and without differences in time to ROSC between crystalloid and early transfusion [12]. In this study, we used the pig as a large animal model, because of the physiological and anatomical similarity to humans, especially in regard to the cardiopulmonary system.…”