A systematic review on the use of topical hemostats in trauma and emergency surgery.

BACKGROUND: A wide variety of hemostats are available as adjunctive measures to improve hemostasis during surgical procedures if residual bleeding persists despite correct application of conventional methods for hemorrhage control. Some are considered active agents, since they contain fibrinogen and thrombin and actively participate at the end of the coagulation cascade to form a fibrin clot, whereas others to be effective require an intact coagulation system. The aim of this study is to provide an evidence-based approach to correctly select the available agents to help physicians to use the most appropriate hemostat according to the clinical setting, surgical problem and patient's coagulation status. METHODS: The literature from 2000 to 2016 was systematically screened according to PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses] protocol. Sixty-six articles were reviewed by a panel of experts to assign grade of recommendation (GoR) and level of evidence (LoE) using the GRADE [Grading of Recommendations Assessment, Development and Evaluation] system, and a national meeting was held. RESULTS: Fibrin adhesives, in liquid form (fibrin glues) or with stiff collagen fleece (fibrin patch) are effective in the presence of spontaneous or drug-induced coagulation disorders. Mechanical hemostats should be preferred in patients who have an intact coagulation system. Sealants are effective, irrespective of patient's coagulation status, to improve control of residual oozing. Hemostatic dressings represent a valuable option in case of external hemorrhage at junctional sites or when tourniquets are impractical or ineffective. CONCLUSIONS: Local hemostatic agents are dissimilar products with different indications. A knowledge of the properties of each single agent should be in the armamentarium of acute care surgeons in order to select the appropriate product in different clinical conditions.

Violation of prophylactic vancomycin administration timing is a potential risk factor for rate of surgical site infections in cardiac surgery patients: a prospective cohort study.

BACKGROUND: Intensivists and cardiothoracic surgeons are commonly worried about surgical site infections (SSIs) due to increasing length of stay (LOS), costs and mortality. The antimicrobial prophylaxis is one of the most important tools in the prevention of SSIs. The objective of this study was to investigate the relationship between the timing of antimicrobial prophylaxis administration and the rate of SSIs. METHODS: A prospective cohort study was carried out over 1-year period in all consecutive adult patients undergoing elective cardiac surgery. The population was stratified in patients whose antimicrobial prophylaxis administration violated or not the vancomycin timing protocol (i.e., when the first skin incision was performed before the end of vancomycin infusion). To compare SSI rates, the cohort was further stratified in patients at low and high risk of developing SSIs. RESULTS: Over the study period, 1020 consecutive adult patients underwent cardiac surgery and according to study inclusion criteria, 741 patients were prospectively enrolled. A total of 60 SSIs were identified for an overall infection rate of 8.1%. Vancomycin prophylaxis timing protocol was violated in 305 (41%) out of 741 enrolled patients. SSIs were observed in 3% of patients without violation of the antimicrobial prophylaxis protocol (13/436) compared with 15.4% of patients with a violation of the timing protocol (47/305) (P < 0.0001). Patients at low risk with protocol violation had a higher occurrence of SSIs (P = 0.004) and mortality (P = 0.03) versus patients at low risk without protocol violation. Similarly, patients at high risk with protocol violation had a higher occurrence of SSIs (P < 0.001) and mortality (P < 0.001) versus patients at high risk without protocol violation. The logistic regression analysis showed that internal mammary artery use (P = 0.025), surgical time (P < 0.001), intensive care unit (ICU) LOS (P = 0.002), high risk of developing SSIs (P < 0.001) and protocol violation (P < 0.001) were risk factors for SSI occurrence as well as age (P = 0.003), logistic EuroSCORE (P < 0.001), ICU LOS (P < 0.001), mechanical ventilation time (P < 0.001) and protocol violation (P < 0.001) were risk factors for mortality. CONCLUSIONS: This study showed that violation of the timing of prophylactic vancomycin administration significantly increased the probability of SSIs and mortality from infectious cause in cardiac surgery patients.

Native gel analysis of macromolecular protein complexes in cultured mammalian cells.

Native gel electrophoresis enables separation of cellular proteins in their non-denatured state. In experiments aimed at analysing proteins in higher order or multimeric assemblies (i.e. protein complexes) it offers some advantages over rival approaches, particularly as an interface technology with mass spectrometry. Here we separated fractions from HEK293 cells by native electrophoresis in order to survey protein complexes in the cytoplasmic, nuclear and chromatin environments, finding 689 proteins distributed among 217 previously described complexes. As expected, different fractions contained distinct combinations of macromolecular complexes, with subunits of the same complex tending to co-migrate. Exceptions to this observation could often be explained by the presence of subunits shared among different complexes. We investigated one identified complex, the Polycomb Repressor Complex 2 (PRC2), in more detail following affinity purification of the EZH2 subunit. This approach resulted in the identification of all previously reported members of PRC2. Overall, this work demonstrates that the use of native gel electrophoresis as an upstream separating step is an effective approach for analysis of the components and cellular distribution of protein complexes.

Effects of dimethyl sulfoxide, pyrrolidine dithiocarbamate, and methylprednisolone on nuclear factor-kappaB and heat shock protein 70 in a rat model of hemorrhagic shock.

BACKGROUND: Nuclear factor kappa B (NF-kappaB) is a transcription factor involved in the inflammatory response. Heat shock protein 70 (HSP70) is involved in the cell protection from various stresses. The aim of this study was to evaluate the effects of dimethyl sulfoxide (DMSO), pyrrolidine dithiocarbamate (PDTC), and methylprednisolone (MP) on liver, renal, and intestinal activation of NF-kappaB and HSP70 in a rat model of hemorrhagic shock (HS). METHODS: Sixty rats were randomized in 6 groups: sham-operated; only HS; HS and resuscitation with blood plus normal saline (NS); HS and resuscitation with blood/NS and 6 mg/kg DMSO; HS and resuscitation with blood/NS and 100 mg/kg PDTC; HS and resuscitation with blood/NS and 30 mg/kg MP. Rats were subjected to HS by blood removal to a mean arterial pressure of 35 to 40 mm Hg through the femoral artery. After 1-hour shock-period, the animals were resuscitated according to the experimental protocol. NF-kappaB and HSP70 expression in liver, kidney, and small intestine was analyzed 1 and 3 hours after resuscitation by immunohistochemistry. RESULTS: HS upregulated NF-kappaB activation and HSP70 expression (p < 0.05). Resuscitation was not associated with a further increase in NF-kappaB and HSP70 activation. DMSO, PDTC, and MP administration resulted in a decreased liver, renal, and intestinal activation of NF-kappaB associated with an increase of HSP70 expression (p < 0.05). CONCLUSIONS: Our results suggest that treatment with DMSO, PDTC, and MP can modulate the expression of NF-kappaB and HSP70 after HS in rats. This modulation may have potential effects in HS through inhibition of the NF-kappaB-dependent production of proinflammatory mediators.

Evaluation of capillary leakage after vasopressin resuscitation in a hemorrhagic shock model.

Background: Hemorrhagic shock (HS) is a major threat to patients with trauma and spontaneous bleeding. The aim of the study was to investigate early effects of vasopressin on metabolic and hemodynamic parameters and endothelium permeability by measuring capillary leakage compared to those of other resuscitation strategies in a HS model. Methods: Forty-five Sprague-Dawley rats were randomized into five groups: S group (n = 5), sham-operated rats without shock or resuscitation; HS group (n = 10), HS and no resuscitation; RL group (n = 10), HS and resuscitation with Ringer's lactate (RL); RLB group (n = 10), HS and resuscitation with two-third shed blood plus RL; and vasopressin group (n = 10), HS and resuscitation with RL, followed by continuous infusion of 0.04 U/kg/min vasopressin. The effects of resuscitation on hemodynamic parameters [mean arterial pressure (MAP), superior mesenteric artery blood flow (MBF), and mesenteric vascular resistances (MVR)], arterial blood gases, bicarbonate, base deficit, and lactate levels as well as on capillary leakage in the lung, ileum, and kidney were investigated. Capillary leakage was evaluated with Evans blue dye extravasation. Results: In the vasopressin group, the MAP was higher than in the RL and RLB groups (p < 0.001), while MBF was decreased (p < 0.001). MVR were increased only in the vasopressin group (p < 0.001). Capillary leakage was increased in the lungs of the animals in the vasopressin group compared to that in the lungs of animals in the RLB group (p < 0.05); this increase was associated with the lowest partial pressure of oxygen (p < 0.05). Conversely, decreased capillary leakage was observed with vasopressin in the ileum (p < 0.05). Increased capillary leakage was observed in the kidney in the RLB and vasopressin groups (p < 0.05). Lastly, vasopressin use was associated with higher base deficit and lactate levels when compared to the RL and RLB groups (p < 0.001). Conclusion: Although vasopressin was proposed as a vasoactive drug for provisional hemodynamic optimization in the early phase of HS resuscitation, the overall findings of this experimental study focus on the possible critical side effects of vasopressin on metabolic parameters and endothelium permeability.

Effect of caspase inhibition on thymic apoptosis in hemorrhagic shock.

In hemorrhagic shock (HS) an increased thymic apoptosis (TA) was described. The aim of this study was to evaluate the effect of administration of the caspase inhibitor N-benzyloxy-carbonil-Val-Ala-Asp-fluoromethylketone (Z-VAD-FMK) during the resuscitation phase on TA, organ dysfunctions, and tumor necrosis factor (TNF)-alpha release in HS. Forty rats were randomly assigned to four groups: no HS/resuscitation (sham); HS/resuscitation with shed blood and normal saline (control); HS/resuscitation with shed blood and phosphate-buffered solution (PBS) (vehicle); and HS/resuscitation with shed blood and Z-VAD-FMK (inhibitor). Rats were subjected to HS by blood removal to a MAP of 35-40 mmHg. After a 1-h shock period, the animals were resuscitated according to the protocol. At 1 and 3 h after resuscitation, transaminases, creatinine, urea, lipase, TNF-alpha, and TA were evaluated. Our study showed that a nonlethal HS is early able to induce organ dysfunctions and increased TA. Administration of Z-VAD-FMK did not significantly decrease organ dysfunctions, while it induced a significant TNF-alpha release. TA was significantly reduced by Z-VAD-FMK after 1 h, but not after 3 h. Our results suggest that postinjury caspase inhibition does not attenuate organ dysfunctions, and also does not permanently reduce TA induced by HS and resuscitation in rats.

Pyrrolidine dithiocarbamate modulates HSP70, iNOS, and apoptosis during hemorrhagic shock resuscitation in rats.

INTRODUCTION: The aim of this study is to evaluate whether hemorrhage and resuscitation affect liver, intestinal, and renal expressions of heat shock protein 70 (HSP70), inducible nitric oxide synthase (iNOS), and apoptosis indexes (TUNEL, caspase-3 activation) and whether the expression of these proteins can be modulated by pyrrolidine dithiocarbamate (PDTC) after a nonlethal hemorrhagic shock (HS) in rats. METHODS: Forty rats were randomized into four groups: sham-operated, only HS, HS/resuscitation with blood plus normal saline (NS), and HS/resuscitation with blood/NS plus PDTC, 15 mg/kg body weight, intravenously. Rats were subjected to HS by blood removal to a mean arterial pressure of 35-40 mmHg through the femoral artery. After 1 hr of shock, the animals were resuscitated according to the experimental protocol. HSP70, iNOS, cleaved caspase-3 expression, and TUNEL were analyzed in liver, small intestine, and kidney 3 hr after resuscitation. RESULTS: HS upregulated HSP70, iNOS, cleaved caspase-3 expression, and induced apoptosis (TUNEL) (p < .05 to < .001). Resuscitation was not associated with further increase of their expressions. The administration of PDTC during resuscitation decreased liver, intestinal, and renal activation of iNOS and apoptosis indexes (p < .05 to < .001), and was associated with further increase in HSP70 expression (p < .05). CONCLUSIONS: Our results show that HS resuscitation with PDTC modulates several signaling pathways (HSP70, iNOS, TUNEL, and caspase-3) in a rat model. The results suggest that PDTC administration--by reducing apoptosis and iNOS expression--may have a potential role in minimizing organ damage after severe hemorrhage.