Hemorrhagic shock resuscitation with a low molecular weight starch reduces neutrophil-endothelial interactions and vessel leakage in vivo.
BACKGROUND
The polymorphonuclear neutrophil (PMN) has been implicated in the pathogenesis of endothelial cell (EC) damage and organ injury following hemorrhagic shock. Pentastarch (PTS), a low substituted medium molecular weight (MW) colloid, improves hemodynamics in hypovolemic shock and cardiac surgery. No data exist comparing the immunomodulation of PTS and Ringer's lactate (RL) on the activation of PMN in hemorrhagic shock in vivo.


METHODS
Using an in vivo murine hemorrhagic shock model (blood withdrawal to maintain 50 mmHg x 45 min), circulating PMN were observed every 15 minutes using intravital microscopy on cremaster muscle. EC-PMN interactions (videorecorded and subsequently analyzed blindly), vessel leakage (live epifluorescence after injection of 50 mg/kg fluorescent albumin) and PMN expression of L-selectin (immunofluorescent monoclonal antibodies and flow cytometry) were evaluated in three resuscitation groups: PTS (7.14 mL/kg 10% pentastarch/0.9% NaCl + shed blood, n = 13), RL (RL [2 x shed blood volume] + shed blood, n = 13) and SHAM (0 hemorrhage, 0 resuscitation, n = 9). Significance was evaluated by ANOVA with Bonferroni correction.


RESULTS
PMN rolling was significantly diminished in PTS and SHAM as compared to RL animals at all time points. Similar differences were found in PMN adherence to EC at most time points onwards from 15 minutes following resuscitation. In vivo vessel permeability was lowest in SHAM and PTS animals (mean 0.274 +/- 0.07 and 0.356 +/- 0.15, respectively, p > 0.05) and highest in RL animals (0.667 +/- 0.09, p < 0.001 vs PTS or SHAM). PMN L-selectin expression tended to be higher in the RL group than either SHAM and PTS groups. There were no flow-mechanics differences between groups (vessel diameter, mean red cell velocity, shear stress, shear rate).


CONCLUSIONS
10% pentastarch reduces RL-associated EC-PMN interactions and vessel leakage following hemorrhagic shock. These results support the use of low MW starches to resuscitate hemorrhagic shock, potentially reducing PMN-mediated tissue injury.
Pascual
J L
JL
Division of General Surgery, McGill University Health Center, McGill University, 687 Pine Avenue West, Montréal, Quebec H3A 1A1, Canada.
Ferri
L E
LE
Chaudhury
P
P
Seely
A J
AJ
Campisi
G
G
Giannias
B
B
Evans
D C
DC
Christou
N V
NV
D000818:Animals; D039481:CD11b Antigen / Q000008:administration & dosage / Q000187:drug effects; D002199:Capillary Permeability / Q000187:drug effects* / Q000502:physiology; D004195:Disease Models, Animal; D004848:Epithelium / Q000187:drug effects* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology* / Q000627:therapeutic use*; D007552:Isotonic Solutions / Q000494:pharmacology* / Q000627:therapeutic use*; D019041:L-Selectin / Q000032:analysis / Q000187:drug effects; D008297:Male; D051379:Mice; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D010952:Plasma Substitutes / Q000494:pharmacology* / Q000627:therapeutic use*; D012151:Resuscitation / Q000379:methods*; D000077325:Ringer's Lactate; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000503:physiopathology
D039481:CD11b Antigen; D006895:Hydroxyethyl Starch Derivatives; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D000077325:Ringer's Lactate; D019041:L-Selectin