Small Volume Resuscitation With Hypertonic Saline Is More Effective in Ameliorating Trauma-Hemorrhagic Shock-Induced Lung Injury, Neutrophil Activation and Red Blood Cell Dysfunction than Pancreatic Protease Inhibition

Traumatic coagulopathy--part 2: Resuscitative strategies

OBJECTIVE

To discuss the current resuscitative strategies for trauma-induced hemorrhagic shock and acute traumatic coagulopathy (ATC).

ETIOLOGY

Hemorrhagic shock can be acutely fatal if not immediately and appropriately treated. The primary tenets of hemorrhagic shock resuscitation are to arrest hemorrhage and restore the effective circulating volume. Large volumes of isotonic crystalloids have been the resuscitative strategy of choice; however, data from experimental animal models and retrospective human analyses now recognize that large-volume fluid resuscitation in uncontrolled hemorrhage may be deleterious. The optimal resuscitative strategy has yet to be defined. In human trauma, implementing damage control resuscitation with damage control surgery for controlling ongoing hemorrhage, acidosis, and hypothermia; managing ATC; and restoring effective circulating volume is emerging as a more optimal resuscitative strategy. With hyperfibrinolysis playing an integral role in the manifestation of ATC, the use of antifibrinolytics (eg, tranexamic acid and aminocaproic acid) may also serve a beneficial role in the early posttraumatic period. Considering the sparse information regarding these resuscitative techniques in veterinary medicine, veterinarians are left with extrapolating information from human trials and experimental animal models.

DIAGNOSIS

Viscoelastic tests integrated with predictive scoring systems may prove to be the most reliable methods for early detection of ATC as well as for guiding transfusion requirements.

SUMMARY

Hemorrhage accounts for up to 40% of human trauma-related deaths and remains the leading cause of preventable death in human trauma. The exact proportion of trauma-related deaths due to exsanguinations in veterinary patients remains uncertain. Survivability depends upon achieving rapid definitive hemostasis, early attenuation of posttraumatic coagulopathy, and timely restoration of effective circulating volume. Early institution of damage control resuscitation in severely injured patients with uncontrolled hemorrhage has the ability to curtail posttraumatic coagulopathy and the exacerbation of metabolic acidosis and hypothermia and improve survival until definitive hemostasis is achieved.

Pharmacological interventions in acute respiratory distress syndrome

Pharmacological interventions are commonly considered in acute respiratory distress syndrome (ARDS) patients. Inhaled nitric oxide (iNO) and neuromuscular blockers (NMBs) are used in patients with severe hypoxemia. No outcome benefit has been observed with the systematic use of iNO. However, a sometimes important improvement in oxygenation can occur shortly after starting administration. Therefore, its ease of use and its good tolerance justify iNO optionally combined with almitirne as a rescue therapy on a trial basis. Recent data from the literature support the use of a 48-h infusion of NMBs in patients with a PaO2 to FiO2 ratio <120 mmHg. No strong evidence exists on the increase of ICU-acquired paresis after a short course of NMBs. Fluid management with the goal to obtain zero fluid balance in ARDS patients without shock or renal failure significantly increases the number of days without mechanical ventilation. On the other hand, patients with hemodynamic failure must receive early and adapted fluid resuscitation. Liberal and conservative fluid strategies therefore are complementary and should ideally follow each other in time in the same patient whose hemodynamic state progressively stabilizes. At present, albumin treatment does not appear to be justified for limitation of pulmonary edema and respiratory morbidity. Aerosolized β2-agonists do not improve outcome in patients with ARDS and one study strongly suggests that intravenous salbutamol may worsen outcome in those patients. The early use of high doses of corticosteroids for the prevention of ARDS in septic shock patients or in patients with confirmed ARDS significantly reduced the duration of mechanical ventilation but had no effect or even increased mortality. In patients with persistent ARDS after 7 to 28 days, a randomized trial showed no reduction in mortality with moderate doses of corticosteroids but an increased PaO2 to FiO2 ratio and thoracopulmonary compliance were found, as well as shorter durations of mechanical ventilation and of ICU stay. Conflicting data exist on the interest of low doses of corticosteroids (200 mg/day of hydrocortisone) in ARDS patients. In the context of a persistent ARDS with histological proof of fibroproliferation, a corticosteroid treatment with a progressive decrease of doses can be proposed.

Hypertonic saline resuscitation enhances blood pressure recovery and decreases organ injury following hemorrhage in acute alcohol intoxicated rodents

BACKGROUND

Acute alcohol intoxication (AAI) impairs the hemodynamic and arginine vasopressin (AVP) counter-regulation to hemorrhagic shock (HS) and lactated Ringer's solution (LR) fluid resuscitation (FR). The mechanism of AAI-induced suppression of AVP release in response to HS involves accentuated nitric oxide (NO) inhibitory tone. In contrast, AAI does not prevent AVP response to increased osmolarity produced by hypertonic saline (HTS) infusion. We hypothesized that FR with HTS during AAI would enhance AVP release by decreasing periventricular nucleus NO inhibitory tone, subsequently improving mean arterial blood pressure (MABP) and organ perfusion.

METHODS

Male Sprague-Dawley rats received a 15-hour alcohol infusion (2.5 g/kg + 0.3 g/kg/h) or dextrose (DEX) before HS (40 mm Hg × 60 minutes) and FR with HTS (7.5%, 4 ml/kg) or LR (2.4 × blood volume removed). Organ blood flow was determined, and brains were collected for NO content at 2 hours after FR.

RESULTS

HTS improved MABP recovery in AAI (109 vs. 80 mm Hg) and DEX (114 vs. 83 mm Hg) animals compared with LR. This was associated with higher (>60%) circulating AVP levels at 2 hours after FR compared with those detected in LR animals in both groups. Neither AAI alone nor HS in DEX animals resuscitated with LR altered organ blood flow. In AAI animals, HS and FR with LR reduced blood flow to the liver (72%), small intestine (65%), and large intestine (67%) compared with shams. FR with HTS improved liver (threefold) and small intestine (twofold) blood flow compared with LR in AAI-HS animals. The enhanced MABP response to HTS was prevented by pretreatment with a systemic AVP V1a receptor antagonist. HTS decreased periventricular nucleus NO content in both groups 2 hours after FR.

CONCLUSION

These results suggest that FR with HTS in AAI results in the removal of central NO inhibition of AVP, restoring AVP levels and improving MABP and organ perfusion in AAI-HS.

Damage Control Immunoregulation: Is There a Role for Low-Volume Hypertonic Saline Resuscitation in Patients Managed with Damage Control Surgery?

Hypertonic saline (HTS) is beneficial in the treatment of head-injured patients as a result of its potent cytoprotective effects on various cell lines. We hypothesize that low-volume resuscitation with 3 per cent HTS, when used after damage control surgery (DCS), improves outcomes compared with standard resuscitation with isotonic crystalloid solution (ICS). This is a 4-year retrospective review from two Level I trauma centers. Patients included had 10 units or more of packed red blood cells during initial DCS. On arrival to the trauma intensive care unit (TICU), patients were resuscitated with low-volume 3 per cent HTS or with conventional ICS. A cohort analysis was performed comparing resuscitation strategies. Univariate analysis of continuous data was done with Student t test followed by multivariate analysis. Of 188 patients included, 76 were in the low-volume HTS group and 112 in the ICS group. Demographics were similar between the groups. Over the next 48 hours after DCS in HTS versus ISC groups, intravenous fluids were given: 1920 ± 455 mL versus 8400 ± 1200 mL ( P < 0.0001); urine output was 4320 ± 480 mL versus 1940 ± 480 mL( P < 0.0001); mean TICU length of stay was 10 ± 8 versus 16 ± 15 days ( P < 0.01); prevalence of acute respiratory distress syndrome was 4.0 versus 13.4 per cent ( P = 0.02); sepsis was 6.6 versus 15.2 per cent ( P = 0.06); multisystem organ failure was: 2.6 versus 16.1 per cent ( P < 0.01); and 30-day mortality was 5.3 versus 15.2 per cent ( P = 0.03). There was no difference for prevalence of renal failure at 5.3 versus 3.6 per cent ( P = 0.58). Low-volume resuscitation with HTS administered after DCS on arrival to the TICU may have a protective effect on the polytrauma patient. We believe that this study demonstrates a role for low-volume resuscitation with HTS to improve outcomes in patients undergoing DCS.

A murine model of hypertonic saline as a treatment for acute spinal cord injury: effects on autonomic outcome

Object

Spinal cord injury (SCI) continues to be a problem without a definitive cure. Research based on improved understanding of the immunological aspects of SCI has revealed targets for treating and ameliorating the extent of secondary injury. Hypertonic saline (HTS), a substance both easy to create and to transport, has been investigated as an immunologically active material that can be used in a clinically relevant interval after injury. In this pilot study, HTS was investigated in a murine model for its abilities to ameliorate secondary injury after a severe spinal cord contusion.

Methods

Female C57Bl/6 mice with severe T8–10 contusion injuries were used as the model subjects. A group of 41 mice were studied in a blinded fashion. Mice received treatments with HTS (HTS, 7.5%) or normal saline solution (NSS, 0.9%) at 2 discreet time points (3 and 24 hours after injury.) A separate group of 9 untreated animals were also used as controls. Animals were assessed for autonomic outcome (bladder function). In a group of 33 mice, histological assessment (cellular infiltration) was also measured.

Results

Bladder function was found to be improved significantly in those treated with HTS compared with those who received NSS and also at later treatment times (24 hours) than at earlier treatment times (3 hours). Decreased cellular infiltration in each group correlated with bladder recovery.

Conclusions

The increased effectiveness of later administration time of the more osmotically active and immunomodulatory substance (HTS) suggests that interaction with events occurring around 24 hours after injury is critical. These events may be related to the invasion of leukocytes peaking at 8–24 hours postinjury and/or the peak benefit time of subject rehydration.

Isotonic and hypertonic crystalloid solutions in the critically ill

Disorders of fluid and electrolyte balance in the critically ill are volume-related, compositional, or both. Targeting 'normal' values for plasma volume, osmolality and electrolytes might not be optimal in conditions as diverse as intracranial trauma/haemorrhage, hepatic encephalopathy, abdominal hypertension, or major surgery, because a hyperosmolar state seems to favourably affect tissue (brain and intestinal) oedema formation. However, adequately powered studies regarding the impact of hypertonic saline on outcome are lacking. Isotonic crystalloids are the cornerstone of resuscitation and must be balanced against natural or artificial colloids and vasopressors. Crystalloid resuscitation is superior to vasopressors in shock associated with blunt trauma, and is at least not inferior to colloids in septic shock. Traditional rules of thumb indicating the need for three to four times the amount of crystalloids for the plasma volume to be replaced are probably erroneous and might have contributed to association of overly aggressive crystalloid resuscitation with poor outcome.

Hypertonic saline resuscitation reduces apoptosis of intestinal mucosa in a rat model of hemorrhagic shock

OBJECTIVE

To investigate the early effects of hypertonic and isotonic saline solutions on apoptosis of intestinal mucosa in rats with hemorrhagic shock.

METHODS

A model of rat with severe hemorrhagic shock was established in 21 Sprague-Dawley (SD) rats. The rats were randomly divided into the sham group, normal saline resuscitation (NS) group, and hypertonic saline resuscitation (HTS) group, with 7 in each group. We detected and compared the apoptosis in small intestinal mucosa of rats after hemorrhagic shock and resuscitation by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), FITC (fluorescein-iso-thiocyanate)-Annexin V/PI (propidium iodide) double staining method, and flow cytometry.

RESULTS

In the early stage of hemorrhagic shock and resuscitation, marked apoptosis of small intestinal mucosa in the rats of both NS and HTS groups was observed. The numbers of apoptotic cells in these two groups were significantly greater than that in the sham group (P<0.01). In the HTS group, the apoptic cells significantly decreased, compared with the NS group (P<0.01).

CONCLUSION

In this rat model of severe hemorrhagic shock, the HTS resuscitation of small volume is more effective than the NS resuscitation in reducing apoptosis of intestinal mucosa in rats, which may improve the prognosis of trauma.

Effects of different resuscitation fluids on the rheologic behavior of red blood cells, blood viscosity and plasma viscosity in experimental hemorrhagic shock

BACKGROUND

Hemorrhagic shock is associated with severe rheological abnormalities. We hypothesized that in the setting of hemorrhagic shock, resuscitation can alter hemorheological characteristics dramatically, and different fluids cause different effects. The aim of this study was to investigate whether the type of fluid administered has an impact on hemorheological characteristics at the early stage of resuscitation in a rodent model of hemorrhagic shock.

METHODS

Animals were randomized into five groups: (1) sham hemorrhage (SHAM); (2) shock and sham resuscitation (SHOCK); (3) shock and resuscitation with normal saline 32 ml/kg (NS); (4) shock and resuscitation with 7.5% hypertonic saline 4 ml/kg (HS); (5) shock and resuscitation with 7.5% hypertonic saline/6% Dextran 70 4 ml/kg (HSD). Hemorheological characteristics were measured at 60 min after resuscitation.

RESULTS

Results showed that NS resuscitation deteriorated red blood cell (RBC) deformability compared with the SHOCK group. The HS group showed improved RBC deformability compared with the NS group, although the differences were not statistically significant. There were significant improvements of RBC deformability at all shear rates in the HSD group compared with the NS group. Whole blood and plasma viscosities decreased significantly in the SHOCK group compared with the SHAM group. At shear rates of 60 and 150 s(-1), the NS group decreased whole blood viscosity compared with the SHOCK group. The HSD group showed elevated plasma viscosity compared with the SHOCK, NS and HS groups.

CONCLUSION

These results suggested that at the early stage of hemorrhagic shock resuscitation, hypertonic-hyperoncotic resuscitation could improve RBC deformability compared with isotonic crystalloid resuscitation. Dextran 70 could elevate plasma viscosity to nearly baseline level. These effects of hypertonic-hyperoncotic resuscitation could be beneficial to maintain microcirculation.

Complement component C5a mediates hemorrhage-induced intestinal damage

BACKGROUND

Complement has been implicated in the pathogenesis of intestinal damage and inflammation in multiple animal models. Although the exact mechanism is unknown, inhibition of complement prevents hemodynamic alterations in hemorrhage.

MATERIALS AND METHODS

C57Bl/6, complement 5 deficient (C5-/-) and sufficient (C5+/+) mice were subjected to 25% blood loss. In some cases, C57Bl/6 mice were treated with C5a receptor antagonist (C5aRa) post-hemorrhage. Intestinal injury, leukotriene B4, and myeloperoxidase production were assessed for each treatment group of mice.

RESULTS

Mice subjected to significant blood loss without major trauma develop intestinal inflammation and tissue damage within 2 hours. We report here that complement 5 (C5) deficient mice are protected from intestinal tissue damage when subjected to hemorrhage (injury score = 0.36 compared with wildtype hemorrhaged animal injury score = 2.89; P < 0.05). We present evidence that C5a represents the effector molecule because C57Bl/6 mice treated with a C5a receptor antagonist displayed limited intestinal injury (injury score = 0.88), leukotriene B4 (13.16 pg/mg tissue), and myeloperoxidase (115.6 pg/mg tissue) production compared with hemorrhaged C57Bl/6 mice (P < 0.05).

CONCLUSIONS

Complement activation is important in the development of hemorrhage-induced tissue injury and C5a generation is critical for tissue inflammation and damage. Thus, therapeutics targeting C5a may be useful therapeutics for hemorrhage-associated injury.

Hypertonic saline up-regulates A3 adenosine receptor expression of activated neutrophils and increases acute lung injury after sepsis

OBJECTIVE

Hypertonic saline resuscitation reduces tissue damage by inhibiting polymorphonuclear neutrophils. Hypertonic saline triggers polymorphonuclear neutrophils to release adenosine triphosphate that is converted to adenosine, inhibiting polymorphonuclear neutrophils through A2a adenosine receptors. Polymorphonuclear neutrophils also express A3 adenosine receptors that enhance polymorphonuclear neutrophil functions. Here we investigated whether A3 receptors may diminish the efficacy of hypertonic saline in a mouse model of acute lung injury.

DESIGN

Randomized animal study and laboratory investigation.

SETTING

University research laboratory.

INTERVENTIONS

The effect of A3 receptors on the efficacy of hypertonic saline resuscitation was assessed in A3 receptor knockout and wild-type mice. Animals were treated with hypertonic saline (7.5% NaCl, 4 mL/kg) before or after cecal ligation and puncture, and acute lung injury and mortality were determined. The effect of timing of hypertonic saline exposure on A3 receptor expression and degranulation was studied in vitro with isolated human polymorphonuclear neutrophils.

MEASUREMENTS AND MAIN RESULTS

Treatment of human polymorphonuclear neutrophils with hypertonic saline before stimulation with formyl methionyl-leucyl-phenylalanine inhibited A3 receptor expression and degranulation, whereas hypertonic saline-treatment after formyl methionyl-leucyl-phenylalanine-stimulation augmented A3 receptor expression and degranulation. Acute lung injury in wild-type mice treated with hypertonic saline after cecal ligation and puncture was significantly greater than in wild-type mice pretreated with hypertonic saline. This aggravating effect of delayed hypertonic saline-treatment was absent in A3 receptor knockout mice. Similarly, mortality in wild-type mice with delayed hypertonic saline-treatment was significantly higher (88%) than in animals treated with hypertonic saline before cecal ligation and puncture (50%). Mortality in A3 receptor knockout mice remained only 50% regardless of timing of hypertonic saline administration.

CONCLUSIONS

Polymorphonuclear neutrophil A3 receptors expression determines whether hypertonic saline resuscitation inhibits or aggravates polymorphonuclear neutrophil-induced acute lung injury. These findings suggest that A3 antagonists could improve the efficacy of hypertonic saline resuscitation by reducing side effects in patients whose polymorphonuclear neutrophils are activated before hypertonic saline treatment.

A3 and P2Y2 receptors control the recruitment of neutrophils to the lungs in a mouse model of sepsis

We have recently shown that A3 adenosine receptors and P2Y2 purinergic receptors play an important role in neutrophil chemotaxis. Chemotaxis of neutrophils to sites of infections is critical for immune defense. However, excessive accumulation of neutrophils in the lungs can cause acute lung tissue damage. Here we assessed the role of A3 and P2Y2 receptors in neutrophil sequestration to the lungs in a mouse model of sepsis. Sepsis was induced by cecal ligation and puncture (CLP) using adult male C57BL/6J mice (wild type [WT]), homozygous A3 receptor knockout (A3KO) mice, and P2Y2 receptor knockout (P2Y2KO) mice. Animals were killed 2, 4, 6, or 8 h after CLP, and peritoneal lavage fluid and blood were collected. Lungs were removed, and neutrophil infiltration was evaluated using elastase as a marker. Leukocyte and bacterial counts in peritoneal lavage fluid and blood samples were determined. Survival after sepsis was determined in a separate group. Leukocyte counts in the peritoneum were lower in A3KO and P2Y2KO mice than in WT mice. Conversely, initial leukocyte counts in the peripheral blood were higher in KO mice than in WT mice. Neutrophil sequestration to the lungs reached a maximum 2 h after CLP and remained significantly higher in WT mice compared with A3KO and P2Y2KO mice (P < 0.001). Survival after 24 h was significantly lower in WT mice (37.5%) than in A3KO or P2Y2KO mice (82.5%; P < 0.05). These data suggest that A3 and P2Y2 receptors are involved in the influx of neutrophils into the lungs after sepsis. Thus, pharmaceutical approaches that target these receptors might be useful to control acute lung tissue injury in sepsis.

Hypertonic saline reduces inflammation and enhances the resolution of oleic acid induced acute lung injury

Background

Hypertonic saline (HTS) reduces the severity of lung injury in ischemia-reperfusion, endotoxin-induced and ventilation-induced lung injury. However, the potential for HTS to modulate the resolution of lung injury is not known. We investigated the potential for hypertonic saline to modulate the evolution and resolution of oleic acid induced lung injury.

Methods

Adult male Sprague Dawley rats were used in all experiments. Series 1 examined the potential for HTS to reduce the severity of evolving oleic acid (OA) induced acute lung injury. Following intravenous OA administration, animals were randomized to receive isotonic (Control, n = 12) or hypertonic saline (HTS, n = 12), and the extent of lung injury assessed after 6 hours. Series 2 examined the potential for HTS to enhance the resolution of oleic acid (OA) induced acute lung injury. Following intravenous OA administration, animals were randomized to receive isotonic (Control, n = 6) or hypertonic saline (HTS, n = 6), and the extent of lung injury assessed after 6 hours.

Results

In Series I, HTS significantly reduced bronchoalveolar lavage (BAL) neutrophil count compared to Control [61.5 ± 9.08 versus 102.6 ± 11.89 × 10³ cells.ml^-1]. However, there were no between group differences with regard to: A-a O2 gradient [11.9 ± 0.5 vs. 12.0 ± 0.5 KPa]; arterial PO2; static lung compliance, or histologic injury. In contrast, in Series 2, hypertonic saline significantly reduced histologic injury and reduced BAL neutrophil count [24.5 ± 5.9 versus 46.8 ± 4.4 × 10³ cells.ml^-1], and interleukin-6 levels [681.9 ± 190.4 versus 1365.7 ± 246.8 pg.ml^-1].

Conclusion

These findings demonstrate, for the first time, the potential for HTS to reduce pulmonary inflammation and enhance the resolution of oleic acid induced lung injury.

Review article: hypertonic saline use in the emergency department

Hypertonic saline (HS) is being increasingly used for the management of a variety of conditions, most notably raised intracranial pressure. This article reviews the available evidence on HS solutions as they relate to emergency medicine, and develops a set of recommendations for its use. To conclude, HS is recommended as an alternative to mannitol for treating raised intracranial pressure in traumatic brain injury. HS is also recommended for treating severe and symptomatic hyponatremia, and is worth considering for both recalcitrant tricyclic antidepressant toxicity and for cerebral oedema complicating paediatric diabetic ketoacidosis. HS is not recommended for hypovolaemic resuscitation.

The influence of volume management on outcome

PURPOSE OF REVIEW

Fluid (volume) therapy is an integral component in the management of critically ill patients and fluid management may influence outcome. There is much controversy, however, about the type, timing and amount of fluid therapy. Here, we discuss the evidence available to guide such choices.

RECENT FINDINGS

Fluid therapy is widely endorsed for resuscitation of critically ill patients across a range of conditions. Yet, the approach to fluid therapy is subject to substantial variation in clinical practice. Emerging data show that the choice, timing and amount of fluid therapy may affect clinical outcomes. Synthetic colloids may increase the risk of acute kidney injury. Albumin may benefit hypoalbuminemic patients with sepsis and acute lung injury but may worsen outcome in traumatic brain injury. Early administration of fluid therapy in sepsis may improve survival but may be unnecessary in patients with penetrating trauma. Later fluid therapy in acute lung injury patients will increase the duration of ventilator dependence without achieving better survival. A positive cumulative balance likely contributes to increased morbidity and mortality after major surgery.

SUMMARY

Emerging evidence shows that choice, timing and amount of fluid therapy affect outcome. Future studies need to focus on these aspects of fluid therapy by means of larger, more rigorous and blinded controlled trials.

Comparison of lung injury after normal or small volume optimized resuscitation in a model of hemorrhagic shock

OBJECTIVE

To compare lung injury induced by a hemorrhagic shock resuscitated with normal saline or with small volumes of a hypertonic/hyperoncotic solution.

DESIGN AND SETTING

Randomized, controlled, laboratory study in an animal research laboratory.

SUBJECTS

Nineteen pigs (43 +/- 4 kg).

INTERVENTIONS

After anesthesia and mechanical ventilation animals were bled to induce a 2-h deep shock and resuscitated for 2 h using normal saline (NS, 2 ml/kg per minute, n = 7) or the association of 7.2% NaCl with 6% hydroxyethylstarch 200/0.5 (HSHES, 4 ml/kg in 10 min followed by 0.2 ml/kg per minute, n = 7) to reach cardiac index and mixed venous oxygen saturation goals. Lungs were removed 6[Symbol: see text]h after the initiation of hemorrhage. Five animals were used as controls without hemorrhage.

MEASUREMENTS AND RESULTS

Resuscitation goals were achieved using 90 +/- 17 ml/kg NS or 6.8 +/- 1.9 ml/kg HSHES. Lung injury was noted in both hemorrhage groups but was not influenced by the type of resuscitation. Extravascular lung water was measured at 9.6 +/- 1.8 ml/kg in the NS group, 9.2 +/- 1.6 ml/kg in the HSHES, group and 6.4 +/- 1 m/kg in the control group. The degree of histological alveolar membrane focal thickening and interstitial neutrophil infiltration were significantly more pronounced in the hemorrhage groups with no difference between the two types of fluid loading. Finally, pulmonary levels of IL-8 were higher after hemorrhage regardless of the type of resuscitation.

CONCLUSIONS

When included in an optimized and goal directed resuscitation, the use of normal saline or a small volume of hypertonic/hyperoncotic solution does not result in a different early hemorrhage-induced lung injury.

Hypertonic saline resuscitation maintains a more balanced profile of T-lymphocyte subpopulations in a rat model of hemorrhagic shock

OBJECTIVE

To investigate the potential and early effect of hypertonic saline resuscitation on T-lymphocyte subpopulations in rats with hemorrhagic shock.

METHODS

A model of rat with severe hemorrhagic shock was established in 18 Sprague-Dawley (SD) rats. The rats were randomly divided into Sham group, HTS group (hypertonic saline resuscitation group) and NS group (normal saline resuscitation group). Each group contained 6 rats. The CD4(+) and CD8(+) subpopulations of T-lymphocytes in peripheral blood were detected respectively before shock and after resuscitation by double antibody labelling and flow cytometry.

RESULTS

In the early stage after hemorrhagic shock, fluid resuscitation and emergency treatment, the CD4(+) lymphocytes of peripheral blood in HTS and NS groups markedly increased. Small volume resuscitation with HTS also induced peripheral CD8(+) lymphocytes to a certain extent, whereas NS resuscitation showed no effect in this respect. Consequently, compared with Sham and HTS groups, CD4(+)/CD8(+) ratio of peripheral blood in NS group was obviously increased, and showed statistically differences.

CONCLUSION

In this model of rat with severe hemorrhagic shock, small volume resuscitation with HTS is more effective than NS in reducing immunologic disorders and promoting a more balanced profile of T-lymphocyte subpopulations regulating network.