Effects of normal saline on hemodynamic and metabolic function during hemorrhagic shock.

<p>EPO, erythropoietin; BW, blood withdrawal; NS, normal saline; BR, blood reinfusion. The inset depicts the time course of the blood withdrawal (ml/kg) ending at 60 minutes in the 65% BW subset and at 80 minutes in the 75% BW group. Numbers in brackets indicate when the number of animals decreased from the preceding time point. Values are shown as mean ± SEM. Differences between groups were analyzed by two-way repeated measures ANOVA. Overall statistical significances for the treatment effect are shown inside each graph. *<i>p</i> ≤ 0.05 denotes statistically significant differences at the specified time point. Open circles denote normal saline (NS) and closed circles denote no fluid administration (No-NS). (<b>A</b>) Effects on hemodynamic and myocardial function. Ao, aortic pressure; HR, heart rate; CI, cardiac index; SVRI, systemic vascular resistance index; LVSWI, left ventricular stroke work index; RVWI, right ventricular stroke work index. There was an overall statistically significant interaction between treatment and time for CI (<i>p</i> < 0.001), LVSWI (<i>p</i> = 0.007), and RVWI (<i>p</i> = 0.009). (<b>B</b>) Effects on metabolic variables. P_ETCO₂, end-tidal carbon dioxide; Ao, aortic; BE, base excess; DO₂, oxygen delivery index; VO₂, oxygen consumption index; VO₂/DO₂, oxygen consumption and delivery ratio.</p

Distributions of the remaining factors for each of the four factor analyses.

<p>(<b>A</b>) Vasopressin effect, showing the 2:1 randomization with 16 pigs allocated to vasopressin also randomized to normal saline, erythropoietin, and level of hemorrhagic shock severity and 8 pigs allocated to no-vasopressin randomized only to normal saline but not to erythropoietin and exposed to the lowest hemorrhagic shock severity; (<b>B</b>) Normal saline effect, showing the 1:1 randomization with 12 pigs allocated to each level and a balanced distribution of the remaining factors; (<b>C</b>) Erythropoietin effect for the 16 pigs that received vasopressin, showing the 1:1 randomization with 8 pigs allocated to each level and a balanced distribution of the remaining factors; and (<b>D</b>) Hemorrhagic shock severity effect for the 16 pigs that received vasopressin, showing the 1:1 randomization with 8 pigs allocated to each level and a balanced distribution of the remaining factors. NS, normal saline; Epo, erythropoietin; BW, blood withdrawal.</p

Hazard ratios for main factors.

<p>Hazard ratios for main factors.</p

Effect of normal saline on indices of organ function/injury.

<p>Numbers in brackets indicate the sample size reflecting animals alive at the specific time point except for HS 150 minute in the no-normal saline group in which two samples were not available. Values are mean SD. BW, blood withdrawal; HS, hemorrhagic shock; BR, blood reinfusion. The data was analyzed using two-way repeated measures ANOVA reporting statistically significant differences from baseline within each group using the Holm-Sidak test for multiple comparisons</p><p>^a<i>p≤</i>0.05</p><p>^b<i>p≤</i>0.01, and</p><p>^c<i>p≤</i>0.001.</p><p>There were no statistically significant differences between groups at any specified time point.</p><p>Effect of normal saline on indices of organ function/injury.</p

Effect of vasopressin on indices of organ function/injury.

<p>Numbers in brackets indicate the sample size reflecting animals alive at the specific time point except for HS 150 minute in the no-vasopressin group in which two samples were not available. Values are mean SD. BW, blood withdrawal; HS, hemorrhagic shock; BR, blood reinfusion. The data was analyzed using two-way repeated measures ANOVA reporting statistically significant differences between groups at specified time points</p><p>*<i>p≤</i>0.05</p><p>^†<i>p≤</i>0.01, and</p><p>^‡<i>p≤</i>0.001, and statistically significant differences from baseline within each group using the Holm-Sidak test for multiple comparisons</p><p>^a<i>p≤</i>0.01, and</p><p>^b<i>p≤</i>0.001.</p><p>Effect of vasopressin on indices of organ function/injury.</p

Effects of vasopressin on hemodynamic and metabolic function during hemorrhagic shock.

<p>EPO, erythropoietin; BW, blood withdrawal; NS, normal saline; BR, blood reinfusion. The inset depicts the time course of the blood withdrawal (ml/kg) ending at 60 minutes in the 65% BW subset and at 80 minutes in the 75% BW group. Numbers in brackets indicate when the number of animals decreased from the preceding time point. Values are shown as mean ± SEM. Differences between groups were analyzed by two-way repeated measures ANOVA. Overall statistical significances for the treatment effect are shown inside each graph. *<i>p</i> ≤ 0.05 denotes statistically significant differences at the specified time point. Open circles denote vasopressin (VP) and closed circles denote vehicle control (No-VP). (<b>A</b>) Effects on hemodynamic and myocardial function. Ao, aortic pressure; HR, heart rate; CI, cardiac index; SVRI, systemic vascular resistance index; LVSWI, left ventricular stroke work index; RVWI, right ventricular stroke work index. (<b>B</b>) Effects on metabolic variables. P_ETCO₂, end-tidal carbon dioxide; Ao, aortic; BE, base excess; DO₂, oxygen delivery index; VO₂, oxygen consumption index; VO₂/DO₂, oxygen consumption and delivery ratio. There was an overall statistically significant interaction between treatment and time for Ao BE (<i>p</i> = 0.040).</p

Survival analysis.

<p>Kaplan-Meier survival curves analyzed using the log-rank test and the Holm-Sidak test for multiple comparisons when applicable. The <i>p</i>-value for each log-rank test results is shown inside each graph. (<b>A</b>) Kaplan-Maier survival curves comparing the effects of vasopressin with normal saline (VP-NS), VP without NS (VP-noVP), no VP with NS (noVP-NS), and neither VP nor NS (noVP-noNS). Pairwise comparisons by the Holm-Sidak test demonstrated significantly lower survival for VP-noNS (*<i>p</i> = 0.035), noVP-NS (<b>†</b><i>p</i> = 0.0198), and noVP-noNS (<b>‡</b><i>p</i> = 0.001) compared with VP-NS. B through E show Kaplan-Maier survival curves for the independent effects of vasopressin (<b>B</b>), normal saline (<b>C</b>), erythropoietin (<b>D</b>), and hemorrhagic shock severity (<b>E</b>) with the remaining factors allocated as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130134#pone.0130134.g001" target="_blank">Fig 1</a>. In parentheses, number of animals alive at 72 hour survival relative to the initial subset.</p

Effects of Intraosseous Erythropoietin during Hemorrhagic Shock in Swine

<div><p>Objective</p><p>To determine whether erythropoietin given during hemorrhagic shock (<i>HS</i>) ameliorates organ injury while improving resuscitation and survival.</p><p>Methods</p><p>Three series of 24 pigs each were studied. In an initial series, 50% of the blood volume (BV) was removed in 30 minutes and normal saline (threefold the blood removed) started at minute 90 infusing each third in 30, 60, and 150 minutes with shed blood reinfused at minute 330 (<i>HS-50_BV</i>). In a second series, the same <i>HS-50_BV</i> protocol was used but removing an additional 15% of BV from minute 30 to 60 (<i>HS-65_BV</i>). In a final series, blood was removed as in <i>HS-65_BV</i> and intraosseous vasopressin given from minute 30 (0.04 U/kg min⁻¹) until start of shed blood reinfusion at minute 150 (<i>HS-65_BV+VP</i>). Normal saline was reduced to half the blood removed and given from minute 90 to 120 in half of the animals. In each series, animals were randomized 1∶1 to receive erythropoietin (1,200 U/kg) or control solution intraosseously after removing 10% of the BV.</p><p>Results</p><p>In <i>HS-50_BV</i>, O₂ consumption remained near baseline yielding minimal lactate increases, 88% resuscitability, and 60% survival at 72 hours. In <i>HS-65_BV</i>, O₂ consumption was reduced and lactate increased yielding 25% resuscitability. In <i>HS-65_BV+VP</i>, vasopressin promoted hemodynamic stability yielding 92% resuscitability and 83% survival at 72 hours. Erythropoietin did not affect resuscitability or subsequent survival in any of the series but increased interleukin-10, attenuated lactate increases, and ameliorated organ injury based on lesser troponin I, AST, and ALT increases and lesser neurological deficits in the <i>HS-65_BV+VP</i> series.</p><p>Conclusions</p><p>Erythropoietin given during HS in swine failed to alter resuscitability and 72 hour survival regardless of HS severity and concomitant treatment with fluids and vasopressin but attenuated acute organ injury. The studies also showed the efficacy of vasopressin and restrictive fluid resuscitation for hemodynamic stabilization and survival.</p></div

Survival curves comparing pigs treated with EPO and controls.

<p>Series <i>HS-50_BV</i> and <i>HS-65_BV+VP</i> include 72 hour survival. The <i>p</i>-values for survival differences between groups were calculated using the Gehan-Breslow test and are shown within each graph along with the resuscitation and survival rates for the combined EPO and control groups. The shaded horizontal bars successively represent; the percentage of blood withdrawn (BW), the interval of hemorrhagic shock after blood withdrawal without fluid administration, the administration of normal saline (NS) as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110908#s2" target="_blank">Method</a>, and blood reinfusion (BR). Shown in <i>65_BV+VP</i> is the vasopressin infusion (VP).</p

Swine model of hemorrhagic shock.

<p>CO, cardiac output; IO, intraosseous; P_ETCO₂, end-tidal PCO₂; ECG, electrocardiogram.</p