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Biomedical subjects

A Acheson

Publications and source records attributed to A Acheson.

40 records · Page 3Linked to original sources

The effect of bystander CPR on survival of out-of-hospital cardiac arrest victims.

The effect of bystander cardiopulmonary resuscitation (CPR) was studied in 2142 emergency medical service (EMS) cardiac arrest runs. When bystander CPR was administered to cardiac arrest victims, 22.9% of the victims survived until they were admitted to the hospital and 11.9% were discharged alive. In comparison, the statistics for cardiac arrest victims who did not receive bystander CPR were 14.6% and 4.7%, respectively (p less than 0.001). A critical factor in patient survival was the amount of time that elapsed before the EMS personnel arrived and administered CPR. Patients who received bystander CPR were more likely to have ventricular fibrillation when the EMS arrived. Other factors relating to patient survival were the location of the victim at the time of the cardiac arrest and the age of the victim. Understanding these factors is important in developing community strategies to treat patients with cardiac arrest out of hospital.

Adult↗

Predictive survival models for resuscitated victims of out-of-hospital cardiac arrest with coronary heart disease.

Resuscitated victims of cardiac arrest with coronary heart disease represent a group of patients with an accelerated mortality rate. Among 227 such patients in our follow-up study, 20% had died at 1 year and 50% were dead in slightly over 3 years. Predictors of death were related to use of digitalis, elevated blood urea nitrogen, cerebral vascular accident, previous myocardial infarction, and age. In a subset of 103 patients in whom ambulatory electrocardiographic recordings were available within 3 months of the arrest event, the presence of complexity and high-frequency ventricular premature beats (VPBs) (greater than or equal to 25/hr) were added to the mortality predictors of digitalis and diuretic therapy and elevated blood urea nitrogen. An almost equal number of patients died suddenly and nonsuddenly. Predictors of sudden death were treatment with quinidine and paired VPBs. Occurrence of arrhythmias was an important addition to the previous mortality predictors related to left ventricular dysfunction.

Actuarial Analysis↗

Lesions and inactivation implicate dorsolateral hindbrain in MFB self-stimulation.

Two experiments explored the role of the motor nucleus of the trigeminal nerve (Mo5) and surrounding area in the rewarding effects of medial forebrain bundle (MFB) stimulation. In the first, eight rats received serial bilateral lesions of the target region. The reward value of MFB stimulation was assessed at 200, 400, and 800 microA using the rate-frequency curve shift paradigm. In five rats, no lesions affecting the motor nucleus or its surrounding area affected the frequency required to maintain half-maximal response rate at any current. One rat with a relatively ventrally placed lesion showed substantial enhancement of stimulation reward value at two currents, while two rats with lesions affecting the area around the descending fibers of the superior cerebellar peduncle (scp) showed substantial increases in required frequency. In the second experiment, six rats received uni- and bilateral injections of lidocaine to temporarily inactivate the target area. Two rats with injections centered near the descending fibers of the scp showed substantial increases in required frequency, as great as 0.30 log(10) units. Two rats with injections slightly rostral to these showed little change in required frequency. Two rats with injections in the ventral cerebellum, just lateral to the fastigial nucleus, showed increases in required frequency, particularly following injections contralateral to the MFB stimulation site. These data are interpreted to imply a role for the area around the lateral pole of the scp, perhaps including axons arising from the cerebellum, in MFB stimulation reward.

Anesthetics, Local↗