Does naloxone alone increase resuscitation rate during cardiopulmonary resuscitation in a rat asphyxia model?
ABSTRACT Cardiac arrest was induced with asphyxia to identify if naloxone alone increases resuscitation rate during cardiopulmonary resuscitation in a rat asphyxia model. The animals were randomized into either a saline group (Sal-gro, treated with normal saline 1 ml iv, n = 8), a low-dose naloxone group (treated with naloxone 0.5 mg/kg iv, n = 8), or a high-dose naloxone group (HN-gro, treated with naloxone 1 mg/kg iv, n = 8) in a blinded fashion during resuscitation. At the end of 10 minutes of asphyxia, cardiopulmonary resuscitation was started, and each drug was administered at the same time. The rate of restoration of spontaneous circulation was seen in 1 of 8, 3 of 8, and 7 of 8 animals in the Sal-gro, LN-gro, and HN-gro, respectively. The rate of restoration of spontaneous circulation in HN-gro was significantly higher than that in Sal-gro (P < .05). Naloxone (1 mg/kg) alone can increase resuscitation rate following asphyxial cardiac arrest in rats.
- SourceAvailable from: Alfredo Nicodemos Cruz SantanaThe American journal of emergency medicine 02/2008; 26(1):113.e5-8. DOI:10.1016/j.ajem.2007.06.029 · 1.15 Impact Factor
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ABSTRACT: We hypothesized that the combination of cardiac pacing and epinephrine would yield a better efficacy for cardiopulmonary resuscitation (CPR) and the combination of 2 therapies at different opportunity would achieve the same results of CPR. Cardiac arrest was induced by clamping the tracheal tubes in 60 Sprague-Dawley rats. At 10 minutes of asphyxia, the animals were prospectively randomized into 5 groups (n = 12/group), and received saline (Sal-gro, 1 mL, intravenous [i.v.]), epinephrine (Epi-gro, 0.4 mg/kg, i.v.), pacing (Pac-gro, transesophageal cardiac pacing combined with saline 1 mL, i.v.), pacing + epinephrine group 1 (PE-gro1, transesophageal cardiac pacing combined with epinephrine 0.4 mg/kg, i.v.), or pacing + epinephrine group 2 (PE-gro2, transesophageal cardiac pacing combined with epinephrine 0.4 mg/kg, i.v., 4 minutes after the transesophageal cardiac pacing initiating and failing to resuscitate the animals), followed by initiation of CPR. Restoration of spontaneous circulation in Sal-gro was lower than in Epi-gro, Pac-gro, PE-gro1, and PE-gro2 (16.67% vs 66.67%, 66.67%, 100%, and 100%; P < .05 or P < .001, respectively). The proportions of withdrawing ventilator and 2-hour survival proportions in Pac-gro and PE-gro2 were higher than in Epi-gro and PE-gro1 (8/8, 10/12 vs 1/8, 2/12, respectively, P < .01, and 7/8, 8/12 vs 1/8, 2/12, respectively, P < .05 or P < .01). Mean survival time in Pac-gro and PE-gro2 were longer than in Epi-gro and PE-gro1 (P < .05 or P < .01). Therefore, the combination of 2 therapies does not always improve outcome of CPR. It is obvious that the combination of transesophageal cardiac pacing with delayed administration of epinephrine yields a better outcome compared to the combination of 2 therapies at the same time during CPR in a rat asphyxia cardiac arrest model.The American journal of emergency medicine 11/2007; 25(9):1032-9. DOI:10.1016/j.ajem.2007.03.013 · 1.15 Impact Factor
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ABSTRACT: The metabolic or late phase of cardiac arrest is highly lethal. Emergency cardiopulmonary bypass (ECPB) can resuscitate many patients even after prolonged cardiac arrest and provides immediate vascular access for correction of metabolic derangement during the reperfusion process. We developed a rodent model of ECPB resuscitation which showed the superiority of ECPB over conventional CPR, especially when combined with hypothermia. For this study we examined a metabolic strategy against ischemia-reperfusion injury (MS-IR) that included: leukoreduction, low Ca(2+), Mg(2+), buffered pH, red blood cells and a colloid. We tested whether ECPB plus MS-IR and/or hypothermia improves short-term hemodynamic outcomes compared to a standard ECPB reperfusate. Using a 2×2 factorial design we tested ECPB with (a) MS-IR versus a standard crystalloid solution; and (b) hypothermia versus normothermia in our rat model. The four reperfusion strategies included: (1) MS-IR plus hypothermia, (2) MS-IR with normothermia, (3) standard plasma-lyte (STD) reperfusate plus hypothermia, or (4) STD plus normothermia. Animals underwent 12 min of untreated asphyxial arrest and were resuscitated with ECPB and one of the four strategies for 30 min. Thereafter, ECPB was discontinued and ventilatory support was provided for 3 hours, while hemodynamic, perfusion and other metrics were serially measured. All rats achieved ROSC with ECPB. Significant differences between the groups emerged after 3 hrs: the best outcomes were in animals with MS-IR plus hypothermia (lactate: 1.1 ± 0.1 mmol/L; MAP: 83 ± 4 mm Hg, seizures: 0/10), while the worst outcomes were with STD and normothermia (lactate: 8.9 ± 1.4 mmol/L, MAP: 36 ± 4 mm Hg, seizures: 7/10, p < 0.001). The outcomes of the other two groups (MS-IR only; hypothermia only) were intermediate. MS-IR and hypothermia improved outcome in an additive fashion. While most human ECPB is applied with a normothermic crystalloid priming solution, we observed that in rodents the addition of MS-IR plus hypothermia resulted in considerable short-term benefit after prolonged arrest. Future long-term and translational survival studies are warranted to optimize ECPB resuscitation methods.Resuscitation 12/2011; 82 Suppl 2:S27-34. DOI:10.1016/S0300-9572(11)70148-4 · 3.96 Impact Factor