Assessment of tissue oxygenation.

A continuous supply of oxygen to all tissues is necessary for the efficient production of ATP, and this supply is considered sufficient when aerobic metabolism is maintained. Nonhealing wounds, necrotizing infections, radiation-induced necrosis, crush injury, decompression illness, and CO poisoning all exhibit impaired tissue oxygenation. The need for efficacy of HBO therapy in such conditions is in part determined by the prevailing state of tissue oxygen supply and demand. The methods currently available or under development for assessing the adequacy of tissue oxygenation include blood gas analysis, transcutaneous oxygen measurement, gastric tonometry, pulse oximetry, near-infrared spectroscopy, functional MR imaging, MR spectroscopy, electron paramagnetic resonance, positron emission tomography, and single photon emission computed tomography. The clinical and experimental applications of these methods are discussed and emphasis is placed on their role in hyperbaric medicine.

Operational use and patient monitoring in a multiplace hyperbaric chamber.

Multiplace hyperbaric chambers can be used to deliver patient care with enormous flexibility. Standard critical care techniques, such as mechanical ventilation, endotracheal suctioning, hemodynamic monitoring, blood gas measurement, and emergency therapy such as cardiopulmonary resuscitation, including defibrillation and cardioversion, can all be performed inside a multiplace chamber. The multiplace chamber can be considered an extension of the intensive care unit. This flexibility is accompanied by increased complexity of chamber operation. Careful attention must be paid to minimization of fire hazards and maintenance of a safe chamber atmosphere. Although life support apparatus can easily be taken inside the chamber and will usually work under hyperbaric conditions, care must be given to facilitate the benefits to the patient of hyperbaric oxygen treatment in the face of potential risks associated with rapid changes in environmental pressure and the partial pressures of the component gases.

Electromyographic biofeedback for gait training after stroke.

OBJECTIVE: To examine the effects of electromyographic (EMG) biofeedback training on the recovery of gait in the acute phase post stroke. DESIGN: Patients were randomly assigned to EMG biofeedback or control groups. They received treatment three times a week for six weeks. All patients were assessed prior to treatment, after 18 treatment sessions, and at three months follow-up. SETTING: The study was carried out at Scunthorpe General Hospital in North Lincolnshire. The subjects were acute stroke patients who had been admitted on to the medical and elderly wards. INTERVENTIONS: The EMG biofeedback group were treated using EMG as an adjunct to physiotherapy. The patients were encouraged to facilitate or inhibit abnormal muscle tone via auditory or visual signals transmitted from electrodes placed over the appropriate muscles. The control group were treated using the same techniques, electrodes were used with this group of patients, but the EMG machine was turned off and faced away from the patient and the therapist to control the placebo effect. OUTCOME MEASURES: A large battery of outcome measures was used for physical and psychological assessment. The physical measures consisted of active movement, muscle tone, sensation, proprioception, mobility and activities of daily living (ADL). The psychological measures included orientation, memory, spatial performance, language and IQ. RESULTS: Twenty-one patients were included in the study. Scores were combined into four groups: mild EMG, severe EMG, mild control and severe control. Results showed that there was an improvement in physical scores for active movement, mobility and ADL over time, but there was no significant difference between the EMG and control groups. Scores on the psychological tests were within normal limits, and there was no difference in performance between the EMG and control groups. CONCLUSIONS: This study showed no significant differences in the rate of improvement after stroke between the two groups. Although EMG biofeedback was used as an adjunct to physiotherapy and represented clinical practice, the results provide little evidence to support the clinical significance of using EMG biofeedback to improve gait in the acute phase after stroke.

Catecholamines: study of interspecies variation.

In the last three decades, numerous articles on plasma catecholamine concentrations in various settings have been published in the medical literature. Despite this abundance of information, no summary article has analyzed the species variations in circulating catecholamine concentrations. In this paper, the plasma catecholamine responses to various stresses in 31 animal groups have been compiled from greater than 200 publications (with greater than 5000 animal subjects). Primitive cartilaginous fish such as the shark and the lamprey have the highest reported basal plasma catecholamine concentrations. Birds, mammals, and teleost fish have the lowest concentrations. The lower circulating catecholamine concentrations parallel anatomical changes in the development of the adrenal medulla and the development of the nervous system. Decapitation, hypoxia, hemorrhage, and hypothermia are the experimental conditions associated with the greatest stress-induced changes in plasma catecholamine concentrations. The differences in experimental design are tabulated to afford the reader an opportunity to compare catecholamine levels among species. The table provides a detailed guide to normal concentrations and normal responses in 31 species. This report gives a dynamic overview of catecholamine concentrations in human and animal physiology and may be particularly helpful to investigators involved in catecholamine research.

Speech modification in near-mute schizophrenics.

Twelve male neat-mute schizophrenics were divided into a model-plus-reinforcement group; a model-only group; and a control group, to test the hypothesis that the presence of a verbalizing model to 35 mm slides would serve as an eliciting stimulus to increase speech output. Significant increases in verbalizations were found over treatment sessions, the model-plus-reinforcement condition showing the most marked improvement. Generalization to the ward was found for only three subjects.