ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The American Heart Association's current standards for CPR indicate that acid-base therapy should be guided by measurements of arterial blood gases. However, we have discovered a striking discrepancy between arterial and venous blood gases during CPR: severe venous hypercarbia and acidosis may coexist with simultaneous arterial alkalosis. Arterial blood gases during CPR, therefore, may not accurately reflect the acidbase status of mixed venous blood and thus may fail to indicate systemic acid-base status.

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

During experimental CPR, a marked venoarterial gradient in Pco2has been reported. This is accompanied by a disproportionate decrease in venous pH and a simultaneous increase in arterial pH. This study includes a case report of human CPR in which simultaneous arterial and mixed venous blood gases were obtained before and after cardiac arrest. Similar venoarterial Pco2gradients were observed subsequently in six additional patients during arrest. These clinical data indicate that arterial blood gases fail to reflect striking increases in venous Pco2and decreases in pH due to respiratory acidosis on the venous side of the circulation.

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The acid-base and electrolyte conditions which favor survival were examined in 105 patients during and after CPR. There was a sharp decrease in survival when arterial pH exceeded 7.55 during the initial 10 min after initiation of CPR. Measurements made one hour after successful resuscitation also demonstrated an increase in mortality when pH exceeded 7.55.Arterial blood lactate also served as a sensitive quantitative indicator of prognosis, both during and one hour after successful CPR. The adverse effects of alkalemia were largely explained by increases in whole-blood bicarbonate, plasma sodium, and plasma osmolality after administration of sodium bicarbonate.

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

In a porcine model of cardiac arrest, the intravascular pressure measured during circulatory standstill was positively correlated with the success of cardiopulmonary resuscitation. When volume was expanded before cardiac arrest, circulatory arrest pressure increased and the success of resuscitation increased. After volume expansion, the hematocrit was reduced and colloid osmotic pressure was decreased. However, neither hematocrit nor colloid osmotic pressure changes were directly related to survival.

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

A porcine model of cardiac arrest with irreversible electromechanical dissociation was associated with highly significant decreases in colloid osmotic pressure in the absence of increases in hematocrit during the initial half hour of CPR. Pulmonary edema was typically observed. These observations are best explained by increases in capillary permeability to plasma proteins. The progression of acidemia was remarkably slow; arterial blood pH remained normal for more than 16 min. Even though there was significant lactic acidosis, concurrent respiratory alkalosis during CPR accounted for the greatly delayed onset of acidemia. There was also an as-yet unexplained increase in plasma osmolality.

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Manual and mechanical chest compressions during CPR were compared in the canine model. Endpoints were hemodynamics produced during CPR, resuscitation success at 30 min, 24-h survival, neurologic function of survivors, and CPR-produced trauma. Ten animals in each group underwent 20 min of ventricular fibrillation, during which CPR was performed for 17 min. Hemodynamics produced with manual and mechanical chest compressions were similar. Seven of ten animals in each group were resuscitated. Five animals from the manual group and four animals from the mechanical group survived for 24 h. Neurologic function of survivors was excellent and similar in each group. There was no significant difference in trauma between the two types of chest compression. The similar results for manual and mechanical chest compression in this canine model suggest that different experimental CPR studies can be compared regardless or whether manual or mechanical chest compressions were performed.

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Echocardiographic studies were conducted during CPR to establish whether blood flow through the heart was passive or whether cardiac compression accounted for forward blood flow. M-mode and two-dimensional echocardiographic studies were performed on anesthetized minipigs during external CPR and open-chest cardiac massage. With external compression, mitral valve closure was observed during compression systole and valve opening during compression diastole. The aortic valve opened during compression systole and closed during compression diastole. Identical observations were made during open-chest cardiac compression.Left ventricular area was computed during compression systole. A 24% reduction in the area of the left ventricle during precordial compression confirmed left ventricular ejection of blood. Saline tracer was injected into the right and left ventricles. Echocardiographic observation of the tracer demonstrated forward blood flow across the pulmonic and aortic outflow tracts during compression. There was minimal valvular regurgitation.These findings support the concept of cardiac compression as a mechanism for forward blood flow during open- and closed-chest CPR.

ISSN:0090-3493    

出版商:OVID    

年代:1985

数据来源: OVID