Theodoros Xanthos

Airway pressure and outcome of out-of-hospital cardiac arrest: A prospective observational study ☆

AIM To assess the usefulness of airway pressure as predictor of return of spontaneous circulation (ROSC), as well as to investigate the optimized ventilation compression strategy during cardiopulmonary resuscitation (CPR). METHODS In this prospective observational study, 300 out-of-hospital cardiac arrest victims were intubated and resuscitated with the use of a ventilator. Mean airway pressure (mPaw) was measured at pre-defined phases of CPR. RESULTS A significant difference in mPaw was observed between survivors and non-survivors after the onset of the third minute of CPR. An mPaw value of 42.5mbar during CPR had specificity and sensitivity of 0.788 and 0.804, respectively, for ROSC (AUC=0.668, p=0.047). During CPR, we found statistically significant differences in mPaw at phases zero (F=4.526, p=0.002), two (F=4.506, p=0.002), four (F=8.187, p<0.0001), five (F=2.871, p=0.024), and six (F=5.364, p<0.0001). CONCLUSION Mean airway pressure was higher in survivors. A value of 42.5mbar was associated with ROSC.

The effect of antioxidant supplementation on bacterial translocation after intestinal ischemia and reperfusion

ABSTRACT The intestine is highly sensitive to ischemia/reperfusion (I/R) injury. Intestinal I/R may cause local tissue injury and disruption of the intestinal mucosal barrier, allowing the passage of viable bacteria and endotoxins from the gastrointestinal lumen to distant organs. This phenomenon, known as bacterial translocation (BT), may lead to systemic disorders with high morbidity and mortality. Oxidative stress mediators such as reactive oxygen species, polymorphonuclear neutrophils and nitric oxide are believed to contribute to the intestinal I/R injury. Many antioxidants have shown protective effects against I/R injury of various organs. The present article provides an overview of studies investigating the effect of antioxidant supplementation on BT after intestinal I/R.

Amiodarone and cardiac arrest: Systematic review and meta-analysis

INTRODUCTION The 2015 Guidelines for Resuscitation recommend amiodarone as the antiarrhythmic drug of choice in the treatment of resistant ventricular fibrillation or pulseless ventricular tachycardia. We reviewed the effects of amiodarone on survival and neurological outcome after cardiac arrest. METHODS We systematically searched MEDLINE and Cochrane Library from 1940 to March 2016 without language restrictions. Randomized control trials (RCTs) and observational studies were selected. RESULTS Our search initially identified 1663 studies, 1458 from MEDLINE and 205 from Cochrane Library. Of them, 4 randomized controlled studies and 6 observational studies met the inclusion criteria and were selected for further review. Three randomized studies were included in the meta-analysis. Amiodarone significantly improves survival to hospital admission (OR=1.402, 95% CI: 1.068-1.840, Z=2.43, P=0.015), but neither survival to hospital discharge (RR=0.850, 95% CI: 0.631-1.144, Z=1.07, P=0.284) nor neurological outcome compared to placebo or nifekalant (OR=1.114, 95% CI: 0.923-1.345, Z=1.12, P=0.475). CONCLUSIONS Amiodarone significantly improves survival to hospital admission. However there is no benefit of amiodarone in survival to discharge or neurological outcomes compared to placebo or other antiarrhythmics.

Therapeutic effects of the combination of inhaled beta2-agonists and beta-blockers in COPD patients with cardiovascular disease

Chronic obstructive pulmonary disease (COPD) is a major health problem worldwide, with co-morbidities contributing to the overall severity and mortality of the disease. The incidence and prevalence of cardiovascular disease among COPD patients are high. Both disorders often co-exist, mainly due to smoking, but they also share common underlying risk factors, such as aging and low-grade systemic inflammation. The therapeutic approach is based on agents, whose pharmacological properties are completely opposed. Beta2-agonists remain the cornerstone of COPD treatment due to their limited cardiac adverse effects. On the other hand, beta-blockers are administered in COPD patients with cardiovascular disease, but despite their proven cardiac benefits, they remain underused. There is still a trend among physicians over underprescription of these drugs in patients with heart failure and COPD due to bronchoconstriction. Therefore, cardioselective beta-blockers are preferred, and recent meta-analyses have shown reduced rates in mortality and exacerbations in COPD patients treated with beta-blockers.

Body mass index and outcome of out-of-hospital cardiac arrest patients not treated by targeted temperature management ☆ ☆☆

Background: Obesity has been demonstrated to increase the risk of out‐of‐hospital cardiac arrest (OHCA) and may influence the quality and effectiveness of cardiopulmonary resuscitation. Our aim was to investigate the association between body mass index (BMI) and the outcome of OHCA victims not treated by targeted temperature management. Methods: This was a prospective observational study of OHCA patients. The patients were categorized according to BMI into two groups: the normal BMI group (nBMI) and the elevated BMI group (eBMI). The primary endpoint was return of spontaneous circulation (ROSC), while secondary outcomes were survival to intensive care unit (ICU) admission and survival to ICU discharge. Results: Of the initial 99 patients who were transported to the Emergency Department, 84 (85%) were included in the study. Mean BMI was 29.8 kg/m2. Thirteen (15.5%) patients achieved ROSC and were admitted to the ICU, with the mean duration of ICU length of stay being 6.7 ± 4.9 days. Survival to ICU admission and ICU discharge were higher in the eBMI group (17.6% vs. 6.25%, p = 0.010 and 10.3% vs. 6.25%, p = 0.021, respectively). Survival to ICU discharge was higher in ventricular fibrillation patients compared to patients with non‐shockable rhythms, irrespectively of their BMI (p = 0.002). All patients that survived to ICU discharge did so with a cerebral performance category score of 2. Conclusions: Survival to ICU admission and ICU discharge were higher in the eBMI group.

Effect of cardiac pacing on sleep-related breathing disorders: a systematic review

Sleep-related breathing disorders are commonly encountered in the middle-aged population, negatively affecting quality of life. Central sleep apnea is associated with congestive heart failure, whereas obstructive sleep apnea is related to different pathophysiologic mechanisms, such as the total or partial occlusion of upper airway tract. Both sleep-related disorders have been associated with increased morbidity, and hence, they have been a target of several treatment strategies. The aim of this systematic review is to evaluate the effect of different types of cardiac pacing on sleep-related breathing disorders in patients with or without heart failure. The PubMed and Cochrane Central Register of Controlled Trials were examined from April 2015 to January 2016. Of the initial 360 studies, 22 eligible trials were analyzed. The included studies were classified according to the type of sleep disorder and the intervention undertaken. The evidence shows that cardiac resynchronization therapy but not atrial overdrive pacing can reduce apneic events in central sleep apnea patients. However, their effect on obstructive sleep apnea is controversial. It can be assumed that pacing cannot be used alone as treatment of sleep-related breathing disorders. Further research is needed in order to elucidate the effect of these interventions in sleep apnea patients.

Metabolomics profiling reveals different patterns in an animal model of asphyxial and dysrhythmic cardiac arrest

Cardiac arrest (CA) is not a uniform condition and its pathophysiology strongly depends on its cause. In this work we have used a metabolomics approach to study the dynamic metabolic changes occurring in the plasma samples of a swine model following two different causes of CA, namely asphyxia (ACA) and ventricular fibrillation (VFCA). Plasma samples were collected at baseline and every minute during the experimental phases. In order to identify the metabolomics profiles characterizing the two pathological entities, all samples were analysed by 1H NMR spectroscopy and LC-MS/MS spectrometry.The metabolomics fingerprints of ACA and VFCA significantly differed during the peri-arrest period and the resuscitation phase. Major alterations were observed in plasma concentrations of metabolites related to tricarboxylic acid (TCA) cycle, urea cycle, and anaplerotic replenishing of TCA. ACA animals showed significant metabolic disturbances during the asphyxial and CA phases, while for VFCA animals this phenomenon resulted shifted at the resuscitation phase. Interestingly, starting from the asphyxial phase, the ACA animals were stratified in two groups based on their metabolomics profiles that resulted to be correlated with the clinical outcome. Succinate overproduction was observed in the animals with the worse outcome, suggesting a potential prognostic role for this metabolite.

Intralipid™ administration attenuates the hypotensive effects of acute intravenous amiodarone overdose in a swine model.

PURPOSE To investigate whether a lipid emulsion could counteract the hypotensive effects of amiodarone overdose after an acute intravenous administration and improve 4 h survival in an established model of swine cardiovascular research. METHODS Twenty pigs were intubated and instrumented to measure aortic pressures and central venous pressures (CVP). After allowing the animals to stabilize for 60 minutes, amiodarone overdose (1 mg/kg/min) was initiated for a maximum of 20 minutes. Afterwards, the animals were randomized into 2 groups. Group A (n = 10) received 0.9% Normal Saline (NS) and Group B (n = 10) received 20% Intralipid® (ILE). A bolus dose of 2 ml/kg in over 2 min time was initially administered in both groups followed by a 45 min infusion (0.2 ml/kg/min) of either NS or ILE. RESULTS All animals survived the overdose and all animals survived the monitoring period of 4 hours. Systolic aortic pressure (SpthAorta) (6.90 vs 14.10 mmHg, P = .006) and mean arterial pressure (MAP) (6.10 vs 14.90 mmHg, P = .001) were higher in the ILE group 2 min after the bolus ILE infusion. This difference was maintained for 15 min after ILE infusion for both SpthAorta (7.85 vs 13.15 mmHg, P = .044) and MAP (7.85 vs 13.15 mmHg, P = .042). Animals that received ILE had higher CVP (11.6 vs 15.7 mmHg, P = .046), an effect which was attenuated 2 and 4 hours post administration. Animals receiving ILE were more acidotic (7.21 vs 7.38, P = .048) in the monitoring period compared to animals receiving NS. CONCLUSIONS Intralipid attenuated the hypotensive effects of amiodarone toxicity for a period of 15 minutes compared to animals receiving NS.

Intraoperative initiation of a modified ARDSNet protocol increases survival of septic patients with severe acute respiratory distress syndrome

PURPOSE To assess the intraoperative initiation and feasibility of a modified NIH-NHLBI ARDS Network Mechanical Ventilation Protocol (mARDSNet protocol) in septic patients with severe ARDS. MATERIALS AND METHODS This prospective observational study included consecutive adult septic patients with severe ARDS who underwent emergency abdominal surgery prior to intensive care unit (ICU) admission. The primary outcome was survival to hospital discharge and at 90 days. Secondary outcomes were intraoperative adverse events and ICU length of stay. RESULTS Seven patients were included. A statistically significant difference in lung compliance [ε=0.150, F(1.053, 3.158)=31.098, p=0.010] and driving pressure [ε=0.263, F(1.844, 5.532)=7.042, p=0.031] was observed with time, while plateau pressure did not changed significantly during surgery [ε=0.322, F(2.256, 6.769)=1.920, p=0.219]. Also, PEEP values were constantly increased during surgery [ε=0.252, F(1.766, 5.297)=9.994, p=0.017], with the highest values being observed towards to the end of the procedure. No intraoperative adverse events were observed. Mean (±SD) ICU length of stay was 10.43 (±2.64) days, while all patients survived to hospital discharge and at 90 days. CONCLUSIONS The intraoperative implementation of our mARDSNet protocol is feasible and may increase the survival of septic patients with severe ARDS if initiated prior to ICU admission.

Survival after cardiac arrest in Greece.

We readwith interest the article by Latsios et al. [1] which illustrates the importance of mechanical compressions in the catheterization laboratory. We would like to congratulate the authors for their persistent efforts in this case. Besides the post-resuscitation complication of sepsis, other factors could be identified for the poor outcome. Considering that right femoral artery and vein access was established after numerous two minute cycles of cardiopulmonary resuscitation (CPR) in pulseless electrical activity cardiac arrest, the total cumulative dose of adrenaline during CPR was deleterious to the ischemic myocardium, aggravating tissue perfusion and decreasing the odds for survival to hospital discharge. In addition, cardiac asystole persisted for about 45min period duringwhich reperfusion efforts via primary percutaneous coronary intervention were attempted. Cardiac asystole for 45 min implies that the prolonged global ischemia had resulted in severe tissue injury and the emergence of ischemic contracture,with reperfusion causing additional injury with initiation of apoptosis and myocardial cell death [2]. Consequently, post-resuscitationmyocardial dysfunction and a severe post-cardiac arrest syndrome characterized by complex neurological, metabolic, and hemodynamic interactions should be expected, making