Discovery of a phylogenetically distinct poxvirus in diseased Crocodilurus amazonicus (family Teiidae).

A novel poxvirus was discovered in Crocodilurus amazonicus (Teiidae) presenting with a debilitating skin disease. The generated first genome sequence of a reptilian poxvirus revealed the closest phylogenetic relationship to avipoxviruses, highlighting potential virus exchanges between avian and reptilian species.

Cold aortic flush and chest compressions enable good neurologic outcome after 15 mins of ventricular fibrillation in cardiac arrest in pigs.

OBJECTIVE: The induction of deep cerebral hypothermia via ice-cold saline aortic flush during prolonged ventricular fibrillation cardiac arrest, followed by hypothermic stasis and delayed resuscitation (emergency preservation and resuscitation), improved neurologic outcome after cardiac arrest in pigs, as compared to conventional resuscitation. We hypothesized that emergency preservation and resuscitation with chest compressions would further improve outcome in the same model. DESIGN: Prospective experimental study. SETTING: University research laboratory. SUBJECTS: : Twenty-four female, large, white breed pigs (27-37 kg). INTERVENTIONS: Fifteen minutes of ventricular fibrillation cardiac arrest were followed by 20 mins of resuscitation with chest compressions (control, n = 8), deep cerebral hypothermia via 200 mL/kg 4 degrees C saline aortic flush and hypothermic stasis (emergency preservation and resuscitation, n = 8), and emergency preservation and resuscitation combined with chest compressions (emergency preservation and resuscitation plus chest compressions, n = 8). At 35 mins after cardiac arrest, cardiopulmonary bypass was initiated, followed by defibrillation. Mild hypothermia was continued for 20 hrs. Pigs were evaluated after 9 days using a neurologic deficit (neurologic deficit score: 100% = brain dead; 0%-10% = normal) and an overall performance category score (overall performance category score: 1 = normal; 2 = slightly handicapped; 3 = severely handicapped; 4 = comatose; 5 = dead/brain dead). MEASUREMENTS AND MAIN RESULTS: Brain temperature decreased from 38.5 degrees C to 15.3 degrees C +/- 3.3 degrees C in the emergency preservation and resuscitation group, and to 11.3 degrees C +/- 1.2 degrees C in the emergency preservation and resuscitation plus chest compressions group. In the control group, restoration of spontaneous circulation was achieved in four out of eight pigs, and one survived to 9 days. In the emergency preservation and resuscitation group, restoration of spontaneous circulation was achieved in seven out of eight pigs and five survived; in the emergency preservation and resuscitation plus chest compressions group, all had restoration of spontaneous circulation and seven survived (restoration of spontaneous circulation, p = .08). Neurologic outcome for (median and interquartile range) the control group included overall performance category score of 3, neurologic deficit score of 45%; for the emergency preservation and resuscitation group, overall performance category score was 3 (2-5) and neurologic deficit score was 45% (36; 50) and in the emergency preservation and resuscitation plus chest compressions group, overall performance category score was 2 (1-3) and neurologic deficit score was 13% (5; 21) (overall performance category score, p = .04; neurologic deficit score emergency preservation and resuscitation vs. emergency preservation and resuscitation plus chest compressions, p = .003). CONCLUSIONS: Emergency preservation and resuscitation by deep cerebral hypothermia combined with chest compressions during prolonged cardiac arrest in pigs are feasible and improve neurologic outcome.

Limits of conventional therapies after prolonged normovolemic cardiac arrest in swine.

AIM: Patients' outcomes after prolonged cardiac arrest are often grim. The aim of this study was to find the longest period of normovolemic, normothermic, cardiac arrest no-flow after which good neurologic outcome can be achieved with conventional therapies. METHODS: Swine (28-37 kg) were subjected to ventricular fibrillation cardiac arrest, after which they were randomized into groups with 13 min (n=6), 15 min (n=6), or 17 min (n=6) of untreated cardiac arrest followed by advanced life support (ALS) for 20 min (epinephrine 0.04 mg/kg every 3 min and vasopressin 0.4 IE/kg every 6 min, no defibrillation attempts), followed by cardiopulmonary bypass (CPB). To mimic an unresuscitable situation after prolonged cardiac arrest, CPB was initiated 20 min after the start of resuscitation, followed by defibrillation attempts. Therapeutic mild hypothermia was applied for 20 h and a final neurologic evaluation (neurologic deficit score, NDS; overall performance category, OPC) was done after 9 days. RESULTS: In the 13-min group, restoration of spontaneous circulation (ROSC) was achieved in five of six swine, four of which survived to day 9, and all had favorable neurologic outcomes [one swine OPC 1, three swine OPC 2, NDS 15% (IQR 6-21)]. In the 15- and 17-min groups, ROSC was achieved in three of six and two of six swine, respectively, one survived to day 9 with OPC 3 in each group, and NDS values were 45 and 58%, respectively (Kruskal-Wallis test for OPC, p=0.048). CONCLUSIONS: In our model, the limit of normovolemic, normothermic, cardiac arrest no-flow time, followed by ACLS, CPB, and prolonged mild hypothermia, seems to be 13 min.

Therapeutic hypothermia with a novel surface cooling device improves neurologic outcome after prolonged cardiac arrest in swine.

OBJECTIVE: Devices for rapid induction of mild hypothermia after cardiac arrest are needed. We hypothesized that the Life Recovery Systems' ThermoSuit System provides effective core cooling by pumping ice water over the skin surface and improves neurologic outcome after prolonged cardiac arrest. DESIGN: Prospective experimental study. SETTING: University research laboratory. SUBJECTS: Large White breed pigs (29 to 35 kg). INTERVENTIONS: Swine were anesthetized and mechanically ventilated. Ten minutes of untreated ventricular fibrillation, 3 mins of basic life support, and 5 mins of advanced cardiac life support, including two 0.4 IU/kg doses of vasopressin, were followed by up to three countershocks. After restoration of spontaneous circulation, swine were randomized to two groups (normothermic control, hypothermia). The hypothermia group was cooled from a pulmonary artery temperature of 38.5 +/- 0.5 degrees C to 33.0 degrees C and kept for 14 hrs. At day 9 of the experiment, overall performance categories scores (1, normal; 2, slightly disabled; 3, severely disabled; 4, comatose; 5, dead, brain dead) and neurologic deficit scores (0%, normal; 100%, brain dead) were assessed. Data are presented as median and interquartile range; group comparison was done with a Mann-Whitney U test. MEASUREMENTS AND MAIN RESULTS: In total, 16 of 22 animals were randomized. Time to target temperature in the hypothermia group (n = 8) was 9.0 (5.3-11.9) mins (cooling rate 0.4 [0.3-0.8] degrees C/min), and all animals achieved an overall performance categories score of 1. In the control group, one swine achieved an overall performance categories score of 1, three achieved a score of 2, and four achieved a score of 3 (p = .002). Neurologic deficit score was 0% (0%-4%) in the hypothermia group and 39% (19%-55%) in the control group (p = .001). No harmful side effects could be observed. CONCLUSIONS: The Life Recovery Systems' ThermoSuit System rapidly and safely induced mild therapeutic hypothermia. Hypothermia improved neurologic outcome in swine after cardiac arrest as compared with normothermia. Further studies are warranted to compare the device with established cooling methods.

Emergency preservation and resuscitation improve survival after 15 minutes of normovolemic cardiac arrest in pigs.

OBJECTIVE: Outcome after prolonged normovolemic cardiac arrest is poor, and new resuscitation strategies have to be found. We hypothesized that the induction of deep hypothermia for emergency preservation and resuscitation (EPR) during prolonged cardiac arrest, before the start of reperfusion, will mitigate the deleterious cascades leading to neuronal death and will thus improve outcome. DESIGN: Prospective experimental study. SETTING: University research laboratory. SUBJECTS: Thirteen pigs, Large White breed (27-37 kg). INTERVENTIONS: After 15 mins of ventricular fibrillation, pigs were subjected to 1) EPR (n = 6), 20 mins of hypothermic stasis induced with a cold saline aortic flush; or 2) 20 mins of conventional resuscitation (n = 7). Then cardiopulmonary bypass was initiated in both groups, followed by defibrillation. Controlled ventilation and mild hypothermia were continued for 20 hrs; survival was for 9 days. For neurologic evaluation, neurologic deficit score (100% = brain dead, 0-10% = normal), overall performance category (1 = normal, 5 = dead or brain dead), and brain histologic damage score were used. MEASUREMENTS AND MAIN RESULTS: In the EPR group, brain temperature decreased from 38.5 degrees C +/- 0.2 degrees C to 16.7 degrees C +/- 2.5 degrees C within 235 +/- 27 secs. Five animals achieved restoration of spontaneous circulation and survived to 9 days: two pigs with overall performance category 2 and three pigs with overall performance category 3. Their neurologic deficit score was 45% (interquartile range 35, 50) and histologic damage score was 142 (interquartile range 109, 159). In the control group, four pigs achieved restoration of spontaneous circulation: one survived to 9 days with overall performance category 3, neurologic deficit score 45%, and histologic damage score 226 (restoration of spontaneous circulation, p = .6; survival, p = .03; overall performance category, p = .02). CONCLUSIONS: EPR is feasible in an experimental pig model and improves survival after prolonged cardiac arrest in pigs. Further experimental studies are needed before this concept can be brought into clinical practice.