Hemoglobin Vesicles prolong the time to circulatory collapse in rats during apnea

Yusuke Naito,Satoki Inoue,Hiromi Sakai,Masahiko Kawaguchi

doi:10.1186/s12871-017-0338-y

Abstract

BackgroundHemoglobin vesicles (HbV) are hemoglobin-based oxygen carriers manufactured by liposome encapsulation of hemoglobin molecules. We hypothesised that the infusion of oxygenated HbV could prolong the time to circulatory collapse during apnea in rats.MethodsTwenty-four Sprague-Dawley rats were randomly divided into four groups (Air, Oxy, NS and HbV). The rats were anaesthetized with isoflurane and the trachea was intubated using 14-gauge intravenous catheters. Rats in the Air group were mechanically ventilated with 1.5% isoflurane in room air, and those in other groups received 1.5% isoflurane in 100% oxygen. Mechanical ventilation was withdrawn 1 min after the administration of rocuronium bromide to induce apnea. After 30 s, 6 mL saline and HbV boluses were infused at a rate of 0.1 mL/s in the NS and HbV groups, respectively. Circulatory collapse was defined as a pulse pressure < 20 mmHg and the time to reach this point (PP20) was compared between the groups. The results were analysed via a one-way analysis of variance and post-hoc Holm–Sidak test.ResultsPP20 times were 30.4 ± 4.2 s, 67.5 ± 9.7 s, 95 ± 17.3 s and 135 ± 38.2 s for the Air (ventilated in room air with no fluid bolus), Oxy (ventilated with 100% oxygen with no fluid bolus), NS (ventilated with 100% oxygen with a normal saline bolus), and HbV (ventilated in 100% oxygen with an HbV bolus) groups, respectively, and differed significantly between the four groups (P = 0.0001). The PP20 times in the HbV group were significantly greater than in the Air (P = 0.0001), Oxy (P = 0.007) and NS (P = 0.04) groups.ConclusionInfusion of oxygenated HbV prolongs the time to circulatory collapse during apnea in rats.

Highlights

Hemoglobin vesicles (HbV) are hemoglobin-based oxygen carriers manufactured by liposome encapsulation of hemoglobin molecules
HbV was developed as an alternative to red blood cell (RBC) transfusion and has exhibited efficacy as components of the resuscitative fluid used to treat haemorrhagic shock in emergency situations using animal models [5, 6]
We found that the apnoea time to a pulse pressure lower than 20 mmHg had the lowest coefficient of variation (CV) value of 0.18

Summary

Introduction

Hemoglobin vesicles (HbV) are hemoglobin-based oxygen carriers manufactured by liposome encapsulation of hemoglobin molecules. Supraglottic airway devices may help to maintain oxygenation, but otherwise, the reinitiation of spontaneous ventilation by waking the patient, or the initiation of emergency intubation pathways, should be considered [1]. Emergency intubation pathways commonly involve invasive airway access that require at least a few minutes of preparation. Hemoglobin vesicles (HbV) are a type of cellular Hbbased oxygen carrier (HBOC) manufactured by the encapsulation of a purified, concentrated Hb solution using liposomes [4]. HbV is stored in a deoxygenated state, but is rapidly oxygenated and administered within extremely short time periods

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