Hypertonic saline infusion in hemorrhagic shock treated by military antishock trousers (MAST) in awake sheep.
OBJECTIVE
To determine the effect of military antishock trousers (MAST) combined with hypertonic saline in controlled hemorrhagic shock in an awake sheep model.


METHODS
Prospective, randomized, controlled study.


METHODS
University research laboratory.


METHODS
Healthy adult sheep (21 to 33.5 kg) were studied in four experimental groups.


METHODS
Sheep underwent cannulation of the jugular vein and the carotid artery. An indwelling catheter was also inserted into their bladders. Mean arterial, pulmonary arterial, pulmonary artery occlusion, and central venous pressures, cardiac and stroke volume indices, systemic and pulmonary vascular resistances, PaO2 and PaCO2, and serum lactate and hemoglobin concentrations were measured at baseline, after induction of hemorrhagic shock, and subsequently during resuscitative treatments of normal saline, MAST, hypertonic saline, and the combination of MAST and hypertonic saline.


METHODS
Controlled hemorrhagic shock was induced by arterial bleeding of 40 mL/kg in all animals. The sheep were randomized into four groups. In group 1 (n = 5), controlled hemorrhagic shock was treated by 5 mL/kg sodium chloride 0.9% (isotonic saline). In group 2 (n = 6), controlled hemorrhagic shock was treated by 5 mL/kg sodium chloride 7.5% (hypertonic saline). In group 3 (n = 5), controlled hemorrhagic shock was treated by MAST inflated to 40 mm Hg followed by 5 mL/kg sodium chloride 0.9%. In group 4, controlled hemorrhagic shock was treated by MAST (40 mm Hg) followed by 5 mL/kg of hypertonic saline.


RESULTS
Arterial bleeding was followed by significant decreases in mean arterial pressure (87 +/- 1 to 41 +/- 4 mm Hg; p < .001), cardiac index (4.6 +/- 0.4 to 2.0 +/- 0.2 L/min/m2; p < .001), and urine output (102 +/- 30 to 13.0 +/- 7 mL/hr; p < .001), and an increase in systemic vascular resistance (1517 +/- 130 to 2601 +/- 370 dyne.sec/cm5; p < .001). MAST inflation in group 3 increased systemic vascular resistance to 3018 +/- 399 dyne.sec/cm5 (p < .05) and mean arterial pressure to 79 +/- 5 mm Hg (p < .05), while cardiac index, urine output, and lactate concentration remained unchanged. Infusion of hypertonic saline after MAST inflation (group 4) resulted in an increase in mean arterial pressure to 99 +/- 4 mm Hg (p < .001), an increase in cardiac index to 4.1 +/- 0.4 L/min/m2 (p < .001), an increase in urine output to 221 +/- 93 mL/hr (p < .001), and a decrease in systemic vascular resistance to 1847 +/- 175 dyne.sec/cm5 (p < .005).


CONCLUSIONS
In hemorrhagic shock, the combination of MAST and hypertonic saline increases mean arterial pressure, improves cardiac output and tissue perfusion during the application of MAST, and also prolongs for > 2 hrs the short beneficial effect of hypertonic saline on mean arterial pressure.
Landau
E H
EH
Department of Urology, Hadassah University Hospital, Jerusalem, Israel.
Gross
D
D
Assalia
A
A
Feigin
E
E
Krausz
M M
MM
D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output; D005260:Female; D005676:Gravity Suits; D006982:Hypertonic Solutions / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D011446:Prospective Studies; D011897:Random Allocation; D012756:Sheep; D012771:Shock, Hemorrhagic / Q000503:physiopathology / Q000628:therapy*
D006982:Hypertonic Solutions