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Biomedical subjects

J R Roberts

Publications and source records attributed to J R Roberts.

At least 163 records · Page 9Linked to original sources
PubMed1980

Endotracheal naloxone reversal of morphine-induced respiratory depression in rabbits.

In an emergency, intravenous access may be difficult to obtain rapidly. Alternate routes of administration for drugs are, therefore, desirable. Our study was performed to determine if naloxone could be efficacious in reversing morphine-induced respiratory depression in rabbits when administered using the endotracheal route. Our results indicate that naloxone administered in this fashion is effective in reversing morphine-induced respiratory depression in the rabbit. Mean minute ventilation was depressed to greater than half of resting baseline levels using morphine sulfate. Endotracheally administered naloxone reversed this respiratory depression and resulted in a greater than five-fold increase in mean minute ventilation above baseline levels. We concluded that endotracheal naloxone is efficacious in reversing morphine-induced respiratory depression in the rabbit. The endotracheal route may be an effective alternative for naloxone administration in man when rapid intravenous access is not obtainable.

Administration, Topical↗
PubMed1979

Blood levels following intravenous and endotracheal epinephrine administration.

The blood levels of epinephrine and its metabolites which were obtained when the drug was given by both the intravenous (IV) and endotracheal (ET) routes were compared. Anesthetized dogs were subjected to radioactive epinephrine in doses of 0.005, 0.03, 0.06, and 0.09 mg/kg administered both intravenously and endotracheally. Blood levels were obtained at 0.25, 0.75, 1.5, 3, 5, 10 and 30 minutes following injection and analyzed by thin layer chromatography. The maximum measured concentration following IV injection was observed at 15 seconds. Epinephrine was rapidly metabolized with 20% of the original concentration detected at 5 minutes following IV injection. When the drug was given by the ET route, the maximum measured concentration was similarly observed at 15 seconds. Following ET installation, initial blood concentrations are sustained over a much longer period of time and 80% of the initial concentration was detected at 5 minutes. Maximum concentrations are approximately one-tenth of those achieved with an equal IV dosage. It is concluded that endotracheally and intravenously administered epinephrine rapidly reach maximum blood levels although there are differences in kinetics between the two routes.

Animals↗
PubMed1979

Endotracheal epinephrine in a canine anaphylactic shock model.

This study was undertaken to determine if epinephrine administered endotracheally is as effective in treating anaphylactic shock as is intravenously administered epinephrine. An animal model of anaphylactic shock was produced in anesthetized dogs by the intravenous administration of histamine phosphate. Both the endotracheal and intravenous routes of epinephrine administration resulted in efficient and effective reversal of histamine-induced hypotension. At the doses employed, the intravenous administration of epinephrine resulted in the production of significantly (p less than 0.05) greater numbers of ventricular cardiac arrhythmias than did the endotracheal route of administration.

Anaphylaxis↗
PubMed1979

Endotracheal epinephrine in cardiorespiratory collapse.

The endotracheal route for the administration of epinephrine has been studied extensively in dogs. There has been little in the medical literature to document the successful use of this technique in humans. The successful use of endotracheally administered epinephrine in two patients with cardiorespiratory collapse is reported. Specific points concerning endotracheal drugs are discussed and a set of guidelines for clinical use is offered.

Epinephrine↗
PubMed1978

Comparison of the pharmacological effects of epinephrine administered by the intravenous and endotracheal routes.

Epinephrine in various dosages was administered to anesthetized dogs by intravenous and endotracheal routes. Both methods produced measurable effects on heart rate, blood pressure, and respiration. Tachycardia occurred more rapidly after endotracheal administration than after intravenous administration. Respiration appeared to be supported more advantageously with the larger endotracheal dosages. The maximum blood pressure rise was delayed only 60 seconds by the endotracheal route. With an endotracheally administered dose of ten times the intravenous dose, equal responses in blood pressure were obtained. However, when equal doses are compared, there is only a two to three fold increase with the intravenous route. The endotracheal route may be less toxic at higher doses, affording greater safety when large amounts of epinephrine are used. It is concluded that endotracheally administered epinephrine produces significant pharmacologic effects in anesthetized dogs.

Animals↗
PubMed1978

Intravenous regional anesthesia--'Bier block'.

The Bier block is ideally suited for management of many types of trauma to an extremity. Blood is removed from an injured extremity by elevation and wrapping, and then a pneumatic tourniquet is applied proximal to the site of injury. Lidocaine is then injected into a vein distal to the tourniquet. The tourniquet prevents entry of the lidocaine into the general circulation while anesthesia is obtained in the extremity; it also provides a bloodless surgical field.

Anesthesia, Conduction↗
PubMed1977

Cutaneous and subcutaneous complications of calcium infusions.

Five infants with hypocalcemia experienced complications after treatment with calcium gluconate intravenously. Inadvertent soft tissue extravasation resulted in erythema, subcutaneous calcification, tissue necrosis, skin slough, and transient radial nerve damage with wrist drop, the latter previously unreported. The soft tissue lesions may be mistaken for cellulitis, abscess, calcified hematoma, or osteomyelitis, resulting in unnecessary antibiotic therapy or surgical intervention. Initially, no clinical abnormality may be apparent. The lesions appear from days to weeks following extravasation. Radiographs are initially negative but soft calcification appears in one to three weeks. Follow-up x-ray films show complete resorption of the calcium over several months. Skin sloughs heal in four to six weeks without skin grafting. Extreme care in the parenteral use of calcium gluconate and conservative treatment of the complications is advocated.

Calcinosis↗
PubMed1977

The continuing emergency care clinic: improving patient compliance with follow-up care.

Traditionally, emergency patients have been noted for high rates of noncompliance with appointments in outpatient clinics for follow-up care. S study of cases referred for follow-up care at the outpatient clinic of The Medical College of Pennsylvania showed that less than 20% of the patients kept their appointments. To cope with this problem, a Continuing Emergency Care (CEC) clinic was established on the assumption that a change in structural environment could change noncompliance behavior patterns. The clinic is a small unit near the emergency department, separate from the larger hospital outpatient clinic area. Patient compliance data were collected on each case referred to the CEC clinic during a three-month period. Findings showed a threefold increase in appointment compliance over the previous study in which referrals were made to the hospital clinics.

Appointments and Schedules↗
PubMed1977

Intravenous regional anesthesia.

A series of 33 patients who underwent intravenous regional anesthesia for treatment of orthopedic and surgical procedures is reported. Intravenous regional anethesia is a safe and reliable alternative to general or other regional anesthesia techniques for use in the emergency department. The technique is easily mastered and requires minimal special equipment. The agent of choice is lidocaine in a dosage of 3 mg/kg administered as a 0.5% solution. Complications are few and are usually related to rapid systemic absorption of the anesthetic agent or minor mistakes in technique.

Adolescent↗
PubMed1976

Solid-phase, magnetic particle radioimmunoassay.

A solid-phase radioimmunoassay system has been developed based on the use of antibodies covalently linked to polymer-coated iron oxide (EnzacrylR). An electro-magnet is employed both to mix the particles during incubation (by switching the field on and off) and to separate the antibody-bound and free fractions. This obviates the need for vertical rotation and for the time-consuming, multiple centrifugations required with conventional solid phase procedures. The system is universally applicable and methods have been established for the assay of thyroxine, human placental lactogen and digoxin. The thyroxine assay was employed as a model and it was shown that the results obtained for serum samples correlated closely with those using a routine liquid-phase radioimmunoassay. The applicability of employing a second antibody linked to the iron oxide particles was also studied.

Binding Sites, Antibody↗
PubMed1976

Feasibility studies of evoked response audiometry in the mentally subnormal.

Evoked response audiometry was attempted on a group of seventy-seven unsedated severly subnormal patients up to the age of twenty-two years. Data of some clinical value were obtained in fifty-seven cases. It is suggested that sedation need only be used if the initial attempt at E.R.A. is unsuccessful. Over twenty per cent of the subjects appeared to have significant hearing loss.

Acoustic Stimulation↗
PubMed1976

An ECG telemetry system for physiological studies on swimmers.

A low frequency telemetry system is described which has been designed to allow high quality ECG measurements to be made on active swimmers. The transmitting antenna is a small loop worn by the swimmer whilst the receiver is fed from a single wire loop around the swimming pool. Both ECG electrodes and the transmitter case are made in a waterproof form which allows the swimmer complete freedom of action to dive and swim normally. The transmitter can be constructed from normal miniature components although the present version has been assembled using thick film techniques which combine high reliability with a reduction in overall volume.

Coronary Care Units↗
PubMed1974

Gowers' syringal haemorrhage.

The second case of Gowers' syringal haemorrhage, successfully treated by surgery, and the first such case in a child, is described. It is suggested that the very slow development of haematomyelia within an existing hydrosyringomyelia may originate from a torn intraspinal vein, deprived of its normal neural and glial support.

Adolescent↗