Page 84 - JSOM Winter 2019

signs and hematocrit results were analyzed using STATA re- TABLE 2 Effects of Hemorrhage at Baseline (T-30), Immediately
®
peated-measures analysis of variance. Data central tendency After Hemorrhage (T-15) and at Intervention (T0)
and dispersion are reported as median and interquartile range, IV
respectively. Statistical significance was set at p < .05. Time Group IO Group IM Group
Variable (min) (n = 5) (n = 5) (n = 5) p
72 86 88
Results –30 (70–74) (82–90) (83–92) .13
Experimental Animal Characteristics
96
100
103
All animals achieved similar levels of shock and equivalent Heart rate –15 (86–101) (98–118) (93–146) .45
levels of hemorrhage (mean 38% of calculated blood vol- (bpm)
ume) as shown in Table 1. While the IV and IM groups had 87 113 111
a lower starting MAP compared with the IO group at T-30 0 (85–89) (111–130) (93–143) .06
(58 and 60mmHg vs 72mmHg, respectively, p = .02) there
were no other significant differences in hemodynamic or lab- p .05 .06 .04
oratory physiologic parameters between the groups at baseline –30 58 72 60 .02
or throughout the experiment. The effects of hemorrhage are (58–59) (69–74) (54–65)
presented in Table 2 with T-30 minutes indicating the prehem-
22
24
23
orrhage baseline. There was a significant drop in perfusion and Mean arterial –15 (22–27) (20–32) (17–24) .54
blood pressure and an increase in heart rate for all groups with- pressure
out any significant differences between groups. There was a (mmHg) 29 44 33
median increase in lactate of 1.17mmol/L (0.78–1.83, p < .01) 0 (22–30) (36–46) (29–39) .10
from start of hemorrhage to the end of the equilibration period.
p <.01 <.01 <.01
TABLE 1 Experimental Characteristics at the End of Hemorrhage –30 98 99 99 .21
(T-30) (97–99) (99–99) (99–100)
Median (IQR) Peripheral
95
98
97
Variable or IV Group IO Group IM Group capillary –15 (95–99) (93–99) (93–99) .94
Analyte (n = 5) (n = 5) (n = 5) p hemoglobin
70 71 67 saturation (%) 99 99 99
Weight (kg) .89 0 .94
(69–72) (64–71) (66–72) (96–100) (99–99) (97 -100)
Core 36.8 36.9 37.0 .75
temperature (°C) (36.3–36.9) (36.3 –37.0) (36.7–37.0) p .85 .28 .50
Heart rate (bpm) 87 113 111 .06 –30 8.3 10.5 8.5 .57
(85–89) (111–130) (93–143) (5.9–9.0) (7.6–18.3) (7.7–9.1)
Mean arterial 29 44 33
pressure (mmHg) (22–30) (36–46) (29–39) .10 Perfusion –15 2.9 3.7 2.8 .60
Peripheral (mL × min × (2.6–4.2) (2.9–3.8) (1.7–3.0)
–1
capillary 99 99 99 100 g of tissue )
–1
hemoglobin (96–100) (99–99) (97–100) .94 0 3.1 4.6 4.0 .24
saturation (%) (2.8–4.7) (4.5–6.5) (3.8–4.5)
Perfusion
(mL × min × 3.1 4.6 4.0 .24 p .03 <.01 .01
–1
100g of tissue ) (2.8–4.7) (4.5–6.5) (3.8–4.5) 1.1 1.1 1.5
–1
1620 1640 1550 –30 (1.0–1.3) (1.1–1.7) (1.4–1.9) .35
Blood loss (mL) .83
(1602–1665) (1475–1640) (1525–1665) 3.3 2.2 3.0
26.0 29.1 30.4 Lactate 0 (2.7–3.4) (1.9–2.5) (2.7–3.4) .75
Hematocrit (%) .06 (mmol/L)
(26.0–26.9) (26.4–29.6) (28.0–32.8)
p <.01 <.01 <.01
LC-MS Analysis
Serum concentrations of TXA peaked at 5 minutes for the
IV and IO routes and at 60 minutes for the IM route (147.8 of the experiment. No animals in the IV or IO groups were
[139.0–222.6], 119.6 [88.0–121.6], and 39.4 [37.8–39.9] μg/ euthanized early.
mL, respectively, p = .005). The half-life of TXA was similar
across all routes, with the IV route being slightly longer than Injection Site Inspection
the IO and IM routes (215.5 [180.6–807.0], 159.2 [128.9- None of the animals had IV, IO, or IM injection site com-
163.6], and 162.5 [90.8-242.7] minutes, respectively, p = plications during the post experimental observation phase.
.275) (Table 3). The serum concentration curves over time for On gross inspection at necropsy, there were no injection site
each group can be found in Figure 1. changes (necrosis, liquefaction, ecchymosis) to the skin, bone
marrow, or muscle for the IV, IO, and IM groups.
Postexperiment Complications
Two of the animals in the IM administration group were eu- Discussion
thanized early due to complications. One animal developed an
arterial access site hematoma and was euthanized 2 days af- The concentration curves for IV and IO administration were
14
ter the experiment. The other was severely hyperkalemic after comparable to work done by Lallemand et al. We also
autotransfusion and was euthanized shortly after completion established that TXA delivered by the IV, IO, and IM routes

82 | JSOM Volume 19, Edition 4 / Winter 2019