Effect of intrathoracic pressure on diastolic function of the heart during cardiopulmonary resuscitation in an animal model of cardiac arrest

의과대학/박사Background and Purpose: : The mechanism controlling blood flow during standard cardiopulmonary resuscitation (CPR) remains controversial. The two most likely explanations at present for generation of blood flow by external chest compression are the thoracic pump and cardiac pump theories. However, diastolic phase of the heart during CPR has never been investigated. Cardiac arrest is not associated with the occurrence of either active diastolic relaxations or cardiac value mechanisms that prevent retrograde blood flow and atrial contraction during ventricular diastole. Investigation of the diastolic filling mechanism during cardiac arrest is important for understanding one of the determinants of cardiac performance. The aim of this study was to investigate the effect of changes in intrathoracic pressure (ITP) on diastolic function of the heart during CPR in a swine model of cardiac arrest. Subjects and Methods: : Twelve domestic male pigs weighing 39.6±8.4 kg were acquired from a single-source breeder for use in this study. The animals were fasted overnight with only access to water. After anesthesia, the right carotid vein, right carotid artery, and both femoral arteries were cannulated with an introducer sheath. Micromanometer-tipped catheters for measuring hemodynamic data were inserted through the sheaths. Carotid blood flow was measured at the left carotid artery with an ultrasonic flow measurement system. Chest tubes were inserted into both thoracic cavities to manipulate and measure the intrathoracic pressure. After 2 minutes of ventricular fibrillation induced by AC current to the right ventricle, the animals received a total of 12 minutes of standard manual cardiopulmonary resuscitation (CPR) comprising two 6-minute courses of CPR consisting of chest tube opening (CTO) for 3 minutes and chest tube closure (CTC) for 3 minutes. A sequence of CPR with CTO or CTC was performed alternatively, according to the randomization schedule. Chest compressors were rotated every 2 minutes. Pressures were measured from the aorta, left ventricle (LV), right ventricle (RV), and right atrium (RA). Carotid blood flow (CBF) and end-tidal carbon dioxide concentration (EtCO2) were also measured. Coronary perfusion pressure (CPP), maximal and minimal dp/dt, and slopes of dp/dt of the ventricles were calculated. Statistical analysis: Normality tests were conducted on the results. A paired t-test or a Wilcoxon test, as appropriate, was used to compare outcomes of CTO and CTC. Results: Ten animals were included in the final analysis. Maximal dp/dt and upslope dp/dt of the RV and LV were higher during CPR than during spontaneous circulation (p<0.001). Minimal dp/dt and downslope dp/dt of the RV and LV were lower during CPR than during spontaneous circulation (p<0.001). Maximal dp/dt, upslope dp/dt, minimal dp/dt, and downslope dp/dt of the RV and LV, CBF, CPP, and EtCO2 did not differ between CPR with CTC and CPR with CTO. Conclusion: Intrathoracic pressure did not affect diastolic filling of the heart during CPR in an animal model of cardiac arrest.ope

Clinical significance of ECG changes in patients with nontraumatic intracraninal hemorrhage.

의학과/석사[한글]중추신경계질환은 다양한 경로로 심혈관계에 영향을 줄 수 있다. 중추신경계질환에 의한 심혈관계 변화는 임상적으로 심전도의 이상으로 확인된 바 있다. 그러나 중추신경계질환에 의한 심혈관계 변화가 생체에서 심근손상을 초래하고, 이에 따라 환자의 예후에도 영향을 주는 지에 대한 보고는 없다. 이번 연구에서는 두개내 출혈 환자에서 발생하는 초기 심전도 변화와 심근손상을 진단하여 그 빈도를 확인하고, 심근손상을 시사하는 임상 소견이 환자의 예후와 어떤 연관이 있는지를 알아보고자 하였다. 증상 발현 이후 6시간이내에 응급실로 내원한 비외상성 두개내 출혈 환자 124예를 대상으로 하였다. 모든 대상 예에서 내원 1시간 이내에 뇌 전산화 단층촬영을 시행하였고, 심전도는 내원 시와 내원 후 24시간에 기록하였고, 심초음파검사는 내원 2시간 이내에 시행하였으며, 혈중 troponin I와 CK-MB 검사는 내원 시와 내원 후 8시간에 시행하였다. 심전도의 이상은 65예(52.4%), 심초음파검사의 이상은 21예(17%), 혈중 troponin I의 증가는 35예 (28.2%), 혈중 CK-MB의 증가는 58예(46.8%)에서 관찰되었다. 심전도 또는, 심초음파검사 상 이상소견의 발생, 혈중 troponon I, 또는 혈중 CK-MB의 상승은 심혈관계 합병증의 발생과 환자의 생존여부과 관계가 있었다. 로지스틱 회귀분석 결과, 심혈관계 합병증에 영향을 주는 요소는 심초음파검사의 이상과 혈중 troponin I의 증가였으며, 환자의 생존에 영향을 주는 요소는 내원 시 의식상태와 심전도 상 이상소견의 발생이었다. 이상의 결과로 비외상성 두개내 출혈 환자에서 심전도 상 이상소견의 발생은 실제적인 심근손상의 발생과 높은 연관성이 있으며, 심혈관계 합병증 발생 및 환자의 생존여부에도 영향을 주는 요소임을 알 수 있었다. [영문]Neurological disease could result in functional and structural abnormalities of the heart. There have been many reports related to ECG change in patient with intracraninal hemorrhage. This study was to investigate clinical significance of electrocardiographic changes observed in patients with nontraumatic intracranial hemorrhage by identifying occurrence of myocardial injury and its correlation with subsequent cardiovascular events and outcome. One hundred and twenty-four patients with nontraumatic intracraninal hemorrhage presented to the emergency department within six hours from onset of the symptom were enrolled in this study. Brain CT, ECGs and echocardiography were done. Blood samples for troponin I and creatine kinase(CK)-MB were drawn immediately and eight hours after admission. Troponin I and CK-MB were measured by chemiluminescent immunoassay, respectively. Abnormal findings of ECG and echocardiography were found in 65 cases(52.4%) and 21 cases(17%), respectively. Elevated levels of serum troponin I and creatine kinase-MB were elevated in 35 cases(28.2%) and in 58 cases(46.8%), respectively. Abnormal findings of echocardiography and ECG, elevated levels of serum troponin I and creatine kinase-MB were associated with an increased risk of cardiovascular event and survival. Logistic regression analysis showed that abnormal echcocardiographic finding and elevation of serum troponin I were the factor associated with development of adverse cardiovascular event and that abnormality in ECG and initial mental status were the factor associated with poor prognosis. This study revealed that ECG changes with intracraninal hemorrhage was associated with actual myocardial damage, development of adverse cardiovascular event and survival.ope

Hypochloraemia is associated with 28-day mortality in patients with septic shock: a retrospective analysis of a multicentre prospective registry

Objectives Hyperchloraemia is associated with poor clinical outcomes in sepsis patients; however, this association is not well studied for hypochloraemia. We investigated the prevalence of chloride imbalance and the association between hypochloraemia and 28-day mortality in ED patients with septic shock. Methods A retrospective analysis of data from 11 multicentre EDs in the Republic of Korea prospectively collected from October 2015 to April 2018 was performed. Initial chloride levels were categorised as hypochloraemia, normochloraemia and hyperchloraemia, according to sodium chloride difference adjusted criteria. The primary outcome was 28-day mortality. A multivariate logistic regression model adjusting for age, sex, comorbidities, acid-base state, sepsis-related organ failure assessment (SOFA) score, lactate and albumin level was used to test the association between the three chloride categories and 28-day mortality. Results Among 2037 enrolled patients, 394 (19.3%), 1582 (77.7%) and 61 (3.0%) patients had hypochloraemia, normochloraemia and hyperchloraemia, respectively. The unadjusted 28-day mortality rate in patients with hypochloraemia was 27.4% (95% CI, 23.1% to 32.1%), which was higher than in patients with normochloraemia (19.7%; 95% CI, 17.8% to 21.8%). Hypochloraemia was associated with an increase in the risk of 28-day mortality (adjusted OR (aOR), 1.36, 95% CI, 1.00 to 1.83) after adjusting for confounders. However, hyperchloraemia was not associated with 28-day mortality (aOR 1.35, 95% CI, 0.82 to 2.24). Conclusion Hypochloraemia was more frequently observed than hyperchloraemia in ED patients with septic shock and it was associated with 28-day mortality