Type 2 diabetes mellitus worsens neurological injury following cardiac arrest: an animal experimental study

Abstract Background Cardiac arrest carries a poor prognosis. The typical cardiac arrest patient is comorbid, and studies have shown that diabetes mellitus is an independent risk factor for increased mortality after cardiac arrest. Despite this, animal studies lack to investigate cardiac arrest in the setting of diabetes mellitus. We hypothesize that type 2 diabetes mellitus in a rat model of cardiac arrest is associated with increased organ dysfunction when compared with non-diabetic rats. Methods Zucker diabetic fatty (ZDF) rats (n = 13), non-diabetic Zucker lean control (ZLC) rats (n = 15), and non-diabetic Sprague Dawley (SprD) rats (n = 8), underwent asphyxia-induced cardiac arrest. Animals were resuscitated and monitored for 180 min after return of spontaneous circulation (ROSC). Blood levels of neuron-specific enolase were measured to assess neurological injury. Cardiac function was evaluated by echocardiography. Results No differences in cardiac output or neuron-specific enolase existed between the groups at baseline. Median levels of neuron-specific enolase 180 min after ROSC was 10.8 μg/L (Q25;Q75—7.6;11.3) in the ZDF group, which was significantly higher compared to the ZLC group at 2.0 μg/L (Q25;Q75—1.7;2.3, p < 0.05) and the SprD group at 2.8 μg/L (Q25;Q75—2.3;3.4, p < 0.05). At 180 min after ROSC, cardiac output was 129 mL/min/kg (SD 45) in the ZDF group, which was not different from 106 mL/min/kg (SD 31) in the ZLC group or 123 mL/min/kg (SD 26, p = 0.72) in the SprD group. Conclusions In a cardiac arrest model, neuronal injury is increased in type 2 diabetes mellitus animals compared with non-diabetic controls. Although this study lacks to uncover the specific mechanisms causing increased neuronal injury, the establishment of a cardiac arrest model of type 2 diabetes mellitus lays the important foundation for further experimental investigations within this field

Thiamine for the Treatment of Cardiac Arrest–Induced Neurological Injury: A Randomized, Blinded, Placebo‐Controlled Experimental Study

Background Thiamine supplementation has demonstrated protective effects in a mouse model of cardiac arrest. The aim of this study was to investigate the neuroprotective effects of thiamine in a clinically relevant large animal cardiac arrest model. The hypothesis was that thiamine reduces neurological injury evaluated by neuron‐specific enolase levels. Methods and Results Pigs underwent myocardial infarction and subsequently 9 minutes of untreated cardiac arrest. Twenty minutes after successful resuscitation, the pigs were randomized to treatment with either thiamine or placebo. All pigs underwent 40 hours of intensive care and were awakened for assessment of functional neurological outcome up until 9 days after cardiac arrest. Nine pigs were included in both groups, with 8 in each group surviving the entire intensive care phase. Mean area under the curve for neuron‐specific enolase was similar between groups, with 81.5 μg/L per hour (SD, 20.4) in the thiamine group and 80.5 μg/L per hour (SD, 18.3) in the placebo group, with an absolute difference of 1.0 (95% CI, −57.8 to 59.8; P=0.97). Likewise, there were no absolute difference in neurological deficit score at the end of the protocol (2 [95% CI, −38 to 42]; P=0.93). There was no absolute mean group difference in lactate during the intensive care period (1.1 mmol/L [95% CI, −0.5 to 2.7]; P=0.16). Conclusions In this randomized, blinded, placebo‐controlled trial using a pig cardiac arrest model with myocardial infarction and long intensive care and observation for 9 days, thiamine showed no effect in changes to functional neurological outcome or serum levels of neuron‐specific enolase. Thiamine treatment had no effect on lactate levels after successful resuscitation