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Biomedical subjects

P Sukhum

Publications and source records attributed to P Sukhum.

11 recordsLinked to original sources
PubMed2001

Mechanical advances in cardiopulmonary resuscitation.

Challenged by the continued high mortality rates for patients in cardiac arrest, the American Heart Association and the European Resuscitation Council developed a new set of guidelines in 2000 to help advance several new and promising cardiopulmonary resuscitation (CPR) techniques and devices. This is the first time these organizations have taken such a bold move, in part because of the poor results with standard closed-chest cardiac massage. The new techniques, interposed abdominal counterpulsation and active compression decompression CPR, each provide greater blood flow to the vital organs in animal models of CPR and lead to higher blood pressures in patients in cardiac arrest. In some clinical studies, both techniques have resulted in a significant increase in survival after cardiac arrest in comparison with standard CPR. Three of the four new CPR devices that were recommended in the new guidelines also provide superior vital organ blood flow and increased blood pressures in comparison with standard CPR. The three devices that improve the efficiency of CPR are the circumferential vest, an active compression decompression CPR device, and an inspiratory impedance valve used in combination with the active compression decompression CPR device. The fourth device type, one that compresses the thorax using an automated mechanical piston compression mechanism, was recommended to reduce the number of personnel required to perform CPR. However, no studies on the automated mechanical compression devices have showed an improvement in hemodynamic variables or survival in comparison with standard CPR. Taken together, these new technologies represent an important step forward in the evolution of CPR from a pair of hands to devices designed to enhance CPR efficiency. Each of these advances is described, and the recent literature about each of them is reviewed.

Cardiopulmonary Resuscitation↗
PubMed2000

Use of an inspiratory impedance threshold valve during cardiopulmonary resuscitation: a progress report.

Building upon studies on the mechanism of active compression-decompression (ACD) cardiopulmonary resuscitation, a new inspiratory impedance threshold valve has been developed to enhance the return of blood to the thorax during the decompression phase of CPR. Use of this device results in a greater negative intrathoracic pressure during chest wall decompression. This leads to improved vital organ perfusion during both standard and ACD CPR. Animal and human studies suggest that this simple device increases cardiopulmonary circulation by harnessing more efficiently the kinetic energy of the outward movement of the chest wall during standard CPR or active chest wall decompression. When used in conjunction with ACD CPR during clinical evaluation, addition of the impedance valve resulted in sustained systolic pressures of greater than 100 mmHg and diastolic pressures of greater than 55 mmHg. The new valve may be beneficial in patients in asystole or shock refractory ventricular fibrillation, when enhanced return of blood flow to the chest is needed to 'prime the pump'. The potential long-term benefits of this new valve remain under investigation.

Airway Resistance↗
PubMed2000

Improving the efficiency of cardiopulmonary resuscitation with an inspiratory impedance threshold valve.

In an effort to improve the efficiency of cardiopulmonary resuscitation (CPR), a new inspiratory impedance threshold valve has been developed to enhance the return of blood to the thorax during the chest decompression phase. This new device enhances negative intrathoracic pressure during chest wall recoil or the decompression phase, leading to improved vital organ perfusion during both standard CPR and active compression-decompression CPR. With active compression-decompression CPR, addition of the impedance threshold valve results in sustained diastolic pressures of >55 mm Hg in patients in cardiac arrest. The new valve shows promise for patients in asystole or shock refractory ventricular fibrillation, when enhanced return of blood flow to the chest is needed to "prime the pump." The potential long-term benefits of this new valve remain under study.

Airway Resistance↗
PubMed1986

Pacemakers of the 1980s. An overview.

Methods and devices for permanent cardiac pacing remained relatively stable for over two decades with use of the single-chamber ventricular demand (VVI) pacemaker. However, changes have occurred in the 1980s and are expected to continue with the availability of more advanced technology and with increasing knowledge about cardiac pacing. The physiologic benefit of the newer dual-chamber atrial synchronous (VDD) and fully automatic, universal (DDD) pacemakers over the VVI pacemaker in patients with permanent complete heart block and normal sinus node function has been established. These newer units not only reestablish atrioventricular synchrony but also are physiologically rate-responsive. The VDD pacemaker is expected to be phased out in favor of the DDD pacemaker. When the atrial rate or interval is lower than the lower rate limit, the VDD pacemaker functions as a VVI, whereas the DDD pacemaker functions as an atrioventricular sequential (DVI) pacemaker to maintain continuous atrioventricular synchrony. Contrary to general belief, patients with complete heart block and normal sinus node function may gain very little physiologic benefit, if any, from DVI pacing. The sinus node will compete with the pacemaker's atrial stimulation when the sinus rate is faster than the DVI pacemaker rate (which usually occurs during activity). Also, the ventricular pacing rate will not vary with physiologic change. The DVI and atrial demand (AAI) pacemakers have been used in some patients with sinus node dysfunction. Increasing exercise tolerance should not be expected in the majority of patients because they are not pacemaker-dependent during activity, ie, their heart rate is higher than the pacemaker rate. However, these pacemakers appear to help in eliminating pacemaker syndrome, which does not infrequently occur with VVI pacemakers. Patients with sinus node dysfunction but without atrioventricular block do not gain more physiologic benefit with a DDD than with a DVI pacemaker. Whether these patients have severe sinus node dysfunction all the time or adequate sinus node function most of the time during follow-up, the DDD pacemaker will function as a noncommitted DVI with atrial sensing (DDI). The early report of DVI pacemaker-induced atrial fibrillation during follow-up has been refuted by more recent works. If the DDD pacemaker is significantly more expensive than the DVI pacemaker, the latter type may be a good alternative for this condition.

Arrhythmias, Cardiac↗
PubMed1979

Echocardiography and fetal heart sounds in the diagnosis of fetal heart block.

A 32-week fetus was demonstrated phonocardiographically and echocardiographically to have a regular atrial rate of 150 per minute and a regular ventricular rate of 39 per minute, indicating complete heart block. The diagnosis was suspected when two groups of heart sounds at two distinct rates were heard on auscultation, and was confirmed by the postnatal ECG. The maternal history was significant for the presence of systemic lupus erythematosus. The basis for the echocardiographic diatnosis of complete heart block, the presence of atrial heart sounds in complete heart block, and the relationship of maternal SLE to congenital heart block are discussed.

Adult↗
PubMedDate not supplied

Failure of thiopental to modify global anoxic injury.

To corroborate thiopental protection from cerebral anoxia after cardiopulmonary arrest, 23 sedated, curarized, adult dogs were asphyxiated by plugging the endotracheal tube. Cardiopulmonary resuscitation (CPR) was started 7 minutes after electrocortical silence. Twelve animals received no other treatment (controls), 10 regained consciousness and spontaneous respirations, but remained decerebrate, blind, unable to drink or feed. Two dogs returned to a normal neurologic state. Ten dogs were treated with thiopental after CPR, 7 received 15 mg/kg the first minute, followed by 23 mg/kg over 1 hour; 3 received 60 mg/kg in the first 3 minutes, followed by 30 mg/kg over 1 hour. Except for 1 dog in the low-dose group that recovered neurologically, thiopental-treated dogs showed no neurological or survival improvement over the controls.

Animals↗