Hydrogen sulfide improves neural function in rats following cardiopulmonary resuscitation.

The alleviation of brain injury is a key issue following cardiopulmonary resuscitation (CPR). Hydrogen sulfide (H2S) is hypothesized to be involved in the pathophysiological process of ischemia-reperfusion injury, and exerts a protective effect on neurons. The aim of the present study was to investigate the effects of H2S on neural functions following cardiac arrest (CA) in rats. A total of 60 rats were allocated at random into three groups. CA was induced to establish the model and CPR was performed after 6 min. Subsequently, sodium hydrosulfide (NaHS), hydroxylamine or saline was administered to the rats. Serum levels of H2S, neuron-specific enolase (NSE) and S100ß were determined following CPR. In addition, neurological deficit scoring (NDS), the beam walking test (BWT), prehensile traction test and Morris water maze experiment were conducted. Neuronal apoptosis rates were detected in the hippocampal region following sacrifice. After CPR, as the H2S levels increased or decreased, the serum NSE and S100ß concentrations decreased or increased, respectively (P<0.0w. The NDS results of the NaHS group were improved compared with those of the hydroxylamine group at 24 h after CPR (P<0.05). In the Morris water maze experiment, BWT and prehensile traction test the animals in the NaHS group performed best and rats in the hydroxylamine group performed worst. At day 7, the apoptotic index and the expression of caspase-3 were reduced in the hippocampal CA1 region, while the expression of Bcl-2 increased in the NaHS group; and results of the hydroxylamine group were in contrast. Therefore, the results of the present study indicate that H2S is able to improve neural function in rats following CPR.

[Clinical significance of D-dimer activity in thrombosis of patients with return of spontaneous circulation after cardiopulmonary resuscitation].

OBJECTIVE: To investigate the clinical significance of D-dimer contents in peripheral blood for monitoring the efficacy of thrombolytic therapy in patients with return of spontaneous circulation (ROSC) of cardiopulmonary resuscitation (CPR) cardiopulmonary resuscitation after cardiac arrest. METHODS: Forty-seven patients with sudden cardiac arrest received CPR according to 2005 American Heart Association (AHA) guidelines for CPR and emergency cardiovascular care (ECC). At the early stage of ROSC, those patients underwent head and breast CT scan if they were in a state of unconsciousness and had unstable vital signs. If intracranial hemorrhage, dissection of aorta and pneumothorax were rule out, and those patients who maintained blood circulation for over 24 hours were included. The expression of D-dimer contents in peripheral blood was determined at 0, 1, 2, 4, 8, 12 h after CPR in all patients. And the patients were randomly divided into control and experiment groups. Prior to thrombolysis, the patients whose D-dimer more than 512 µg/L were classified as Group A (n = 17); those whose D-dimer below 512 µg/L Group B (n = 14); and the remaining control group whose family members refused thrombolytic therapy Group C (n = 16). The general data, Glasgow coma scale, survival rate and the change of D-dimer in peripheral blood were analyzed. RESULTS: In Group A, D-dimer level began to increase significantly at CPR 1 hour. It peaked at CPR 2 hours then decreased gradually. The final survival rate was 67%. The survival rate and GCS were higher than those of Groups B and C. In Group B, the D-dimer concentrations began to increase gradually at CPR1 hour, peaked at CPR 12 hours and then decreased. The survival rate and GCS was lower than those of Group A and similar to those of Group C. Group C was control group with no thrombolysis. CONCLUSION: For those ROSC patients with D-dimer concentrations significantly higher than usual, the pathogenesis of cardiac arrest may be concerned with thromboembolism, thrombosis in circulatory system and hyperviscosity. After an initiation of thrombolytic therapy, blocked blood vessels are recanalized, blood circulation improves and the cause of cardiac arrest is removed. Thus their survival rate becomes better. For those with D-dimer concentrations no higher than usual, the cause of cardiac arrest is not concerned with thromboembolism, thrombolytic therapy can not improve the patient outcome. And the final survival rate remains unchanged. The significance of thrombolytic therapy is none.

[Identification and diagnosis of myocardial damage and acute myocardial infarction during cardiopulmonary resuscitation].

OBJECTIVE: To observe the change in contents of creatine kinase isoenzyme MB (CK-MB) and cardiac troponin I (cTnI) in peripheral blood, the elevation of ST in electrocardiogram, and the result of coronary arteriography, to identify myocardial damage and acute myocardial infarction during cardiopulmonary resuscitation (CPR). METHODS: Twenty-six patients with sudden cardiac arrest received CPR, and those patients who had blood circulation maintained for over 24 hours were included. The expression of CK-MB and cTnI activation in peripheral blood were determined at 0, 4, 8, 12, 16 and 20 hours after CPR in all patients. Electrocardiogram was checked every 2 hours in all patients. If CK-MB, cTnI and ST segment of electrocardiogram was higher than usual, or myocardial infarct with suspicious elevation of ST (STEMI), coronary arteriography and interventional therapy were carried out immediately. Patients were divided into three groups. The patients who were not found to have coronary artery block were classified as group A (15 cases), those who were found to have coronary artery block were group B (6 cases), and the remaining patients in whom ST segment of electrocardiogram did not elevate, and coronary arteriography and interventional therapy were not consider were classified as group C (5 cases). Control group consisted of 15 healthy people (group D). The change in CK-MB and cTnI in peripheral blood and the elevation of electrocardiogram ST segment were analyzed. RESULTS: In group A, CK-MB level began to elevate at CPR 4 hours, and it peaked at CPR 12 hours. cTnI began to raise at CPR 4 hours, peaking at CPR 16 hours, then decreased gradually. Elevation of ST was seen in more than two leads in electrocardiogram at the beginning of restoration of spontaneous circulation (ROSC), then lowered quickly, and the decrease exceeded 50% of the elevation at ROSC 2 hours. In group B, the levels of CK-MB and cTnI began to increase at CPR 4 hours, and remained elevated at CPR 20 hours. ST segment was elevated in more than two leads in electrocardiogram at the beginning of ROSC, and remained elevated after ROSC 2 hours. In group C, the CK-MB and cTnI concentrations were increased 4 hours after successful CPR, and reached peak at CPR 12, 16 hours respectively, then they decreased. ST segment of electrocardiogram was not elevated. In group D, the CK-MB and cTnI concentration was in the normal range. ST segment of electrocardiogram was not elevated. CONCLUSION: All patients manifested myocardial damage after CPR. Some patients showed STEMI after CPR. CK-MB and cTnI concentrations increased gradually after successful CPR without specificity for earlier identification of myocardial damage and STEMI. It is necessary to find a new reliable marker to check for myocardial damage. Relatively speaking, elevation of the ST segment in electrocardiogram has more predictive value. A decrease exceeds 50% of the elevation of ST segment in electrocardiogram at ROSC 2 hours, or the peak of contents of CK-MB and cTnI appear at CPR 12 hours or 16 hours indicates myocardial damage. If the elevation of ST segment does not descend after ROSC 2 hours, or the levels of CK-MB and cTnI remain elevated at CPR 20 hours, STEMI should be suspected, and it is necessary to undertake interventional therapy or thrombolysis therapy.