A comparison of epinephrine only, arginine vasopressin only, and epinephrine followed by arginine vasopressin on the survival rate in a rat model of anaphylactic shock
ABSTRACT Epinephrine and more recently arginine vasopressin (AVP) alone or in combination have been proposed in patients with anaphylactic shock, but few experimental data exist. The authors investigated the effects of epinephrine only, AVP only, or epinephrine followed by AVP in a model of anaphylactic shock.
Ovalbumin-sensitized Brown Norway rats were anesthetized, intubated, and shock induced with ovalbumin. Rats (n = 6/group) were randomly allocated to receive 5 min after shock onset: (1) saline (no-treatment group); (2) two boluses of epinephrine followed by continuous infusion (epinephrine group); (3) AVP bolus followed by continuous infusion (AVP group); (4) epinephrine bolus followed by AVP continuous infusion (epinephrine + AVP group). Mean arterial pressure (MAP) and skeletal muscle oxygen pressure (PtiO2) were measured. Continuous infusion rates were titrated to reach MAP values of 60 mmHg. Survival was analyzed.
Without treatment, MAP and PtiO2 decreased rapidly with 0% survival. In the epinephrine group, MAP and PtiO2 recovered after an initial decrease, with 84% survival. In the AVP group, MAP was partially restored and subsequently decreased; PtiO2 values decreased to values similar to those in the no-treatment group; survival was 0%. In the epinephrine + AVP group, MAP and PtiO2 values increased more slowly as compared with the epinephrine group; survival was 100%.
In this model of anaphylactic shock, early treatment with epinephrine followed by continuous epinephrine or vasopressin infusion resulted in an excellent survival rate, whereas vasopressin only resulted in a 100% death rate. These experimental results suggest that epinephrine must still be considered as the first-line drug to treat anaphylactic shock.
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ABSTRACT: Allergens can induce anaphylactic shock and death due to serve hypotension. Potassium channel blockers (K(+)(ATP)) such as glyburide (GLY) induce vasoconstriction. The effect of (K(+)(ATP)) channel blockers on anaphylactic shock is poorly understood. Objective of the study was to test the hypothesis that GLY reduces hypotension induced in anaphylactic shock and increases survival. Rats were grouped into: G1-N=Naïve; G2-SC=Sensitized-Control; G3-SG=Sensitized-GLY (glyburide 40 mg/kg); G4-SE=Sensitized-EPI (epinephrine 10 mg/kg). G2 to G4 groups were sensitized with ovalbumin (OVA) and shock was induced by i.v. injection of OVA. Treatments were administered intravenously 5 min later. Mean arterial pressure (MAP), heart rate (HR), and mean survival time (MST) were measured for 60 min following OVA injection and treatments administration. At the end of the experiment, blood withdrawal was performed to measure plasma levels of histamine, leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)) and prostaglandin F(2) (PGF(2)). Additionally blood gas (paO2, paCO2, SaO2) and electrolytes (Na(+), K(+) and Ca (++)) were measured. MAP was normal in G1-N; severe hypotension, negative inotropic and short MST were observed in G2-SC; normalization of MAP, with lesser negative inotropism and increased MST were observed in G3-SG; full recovery was observed in G4-SE. Histamine level was significantly higher in G2-SC; reduced in G3-SG and G4-SE. PGE(2) increased in G3-SG; PGF(2) increased in G2-SC and G3-SG. Na(+) and Ca (++) concentration decreased in sensitized rats but reversed in treated groups, without change in K(+) concentration. In conclusion, our data suggest that administration of GLY reduced hypotension and increases survival time in rat anaphylactic shock.European journal of pharmacology 11/2013; 720(1-3):166-73. DOI:10.1016/j.ejphar.2013.10.031 · 2.59 Impact Factor
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ABSTRACT: The prevalence of anaphylaxis occurring during pregnancy is approximately 3 cases per 100,000 deliveries. The management of anaphylaxis occurring during the third trimester of pregnancy may be challenging because of the additive effects of aortocaval compression and cardiovascular disturbances of anaphylaxis. In this review, we identify the clinical signs of anaphylaxis occurring during labor and cesarean delivery, discuss the more common allergens that cause anaphylaxis during this clinical setting, and develop a rational approach to the identification of the offending allergen. We also suggest strategies for the management of anaphylaxis occurring during the third trimester of pregnancy, including the prompt administration of epinephrine and emergency cesarean delivery in cases of severe reactions. Evidence is limited to case reports and extrapolation from nonfatal and fatal cases, interpretation of pathophysiology, and consensus opinion.Anesthesia and analgesia 12/2013; 117(6):1357-1367. DOI:10.1213/ANE.0b013e3182a706c7 · 3.42 Impact Factor
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ABSTRACT: Background:Optimization of cerebral oxygenation after pediatric cardiac arrest (CA) may reduce neurological damage associated with the post-CA syndrome. We hypothesized that important alterations in regional partial pressure of brain tissue oxygen (PbO2) occur after resuscitation from CA and that clinically relevant interventions such as hyperoxia and blood pressure augmentation would influence PbO2.Methods:Cortical and thalamic PbO2 were monitored in immature rats subjected to asphyxial CA (9 or 12 min asphyxia) and sham-operated rats using oxygen sensors.Results:Thalamus and cortex showed similar baseline PbO2. Post-resuscitation there was early and sustained cortical hypoxia in an insult-duration fashion. In contrast, thalamic PbO2 initially increased four-fold, and afterwards returned to baseline values. PbO2 was FiO2-dependent, and the response to oxygen was more pronounced after a 9 min vs. 12 min CA. After a 12 min CA, PbO2 was modestly affected by blood pressure augmentation using epinephrine in the thalamus but not cortex.Conclusion:After asphyxial pediatric CA, there is marked regional variability of cerebral oxygenation. Cortical hypoxia is pronounced and appears early, while thalamic hyperoxia is followed by normoxia. Compromised PbO2 in the cortex may represent a relevant and clinically measurable therapeutic target aimed at improving neurological outcome after pediatric CA.Pediatric Research (2013); doi:10.1038/pr.2013.220.Pediatric Research 11/2013; DOI:10.1038/pr.2013.220 · 2.84 Impact Factor