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Biomedical subjects

R L Watson

Publications and source records attributed to R L Watson.

At least 19 recordsLinked to original sources
PubMed1992

The effects of exercise on serum potassium levels.

In view of the significant influence of potassium on the heart, a decision was made to study the effect of exercise on this important ion in two exercise groups of different intensity. The first group consisted of 44 individuals with known coronary artery disease participating in a supervised cardiac rehabilitation program while the other consisted of 30 healthy joggers. Postexercise mean potassium levels were higher in both groups than resting baseline values. In addition, 5 of 44 participants in the coronary artery disease group experienced major potassium increases of 0.9 mmol/L or more while 7 of 30 healthy joggers experienced this magnitude of increase. Remaining unanswered is the question of whether such abrupt rises in potassium levels in this subset of patients alter their vulnerability to cardiac rhythm and conduction disturbances. A question is also raised as to whether rapid return of potassium levels to baseline postexercise contributes to any risks.

Aged↗
PubMed1990

Potassium and calcium intake, excretion, and homeostasis in blacks, and their relation to blood pressure.

Blacks in the United States have higher blood pressures than whites. They ingest and excrete less calcium and potassium. There is some evidence that blacks have a difference in vitamin D metabolism that might increase any problem caused by low calcium intake. Some studies can be interpreted to suggest that calcium or potassium therapy has greater hypotensive effects in blacks than in whites. Decreased intake of calcium and potassium may be major causes of the greater prevalence of hypertension in blacks than in whites.

Black People↗
PubMed1989

Medical and financial implications of discontinuing a statewide free insulin program involving 3,720 people.

In 1981 a statewide program supplying free insulin to 3,720 patients of state health clinics was discontinued. We attempted to assess whether this action had an adverse effect medically and financially on those concerned. A computer randomized sample of 351 patients (9%) was studied by personal interview and questionnaire. Information obtained focused on certain events that occurred 18 months before and after the program ceased. Measurements used to determine medical impact were number of hospitalizations, emergency room and physician visits, changes in weight and glucose levels, and episodes of ketoacidosis. Financial impact was measured by cost of hospitalization and physician visits. Our results revealed no significant changes in any of the medical parameters studied except for fasting serum glucose levels above 300 mg/dl, which occurred less frequently after the free insulin program was discontinued. There were fewer hospitalizations, more visits to physicians, and no change in number of emergency room visits after discontinuance of the free program. The overall cost saving was estimated to be +883,558 for the 18-month study period, in addition to the +550,000 the plan had been costing the state.

Blood Glucose↗
PubMed1983

The effects of morphine, nalbuphine, and butorphanol on adrenergic function in canine saphenous veins.

Saphenous vein rings mounted in organ chambers containing Krebs-Ringer solution were used to determine if the venodilator effects of morphine, nalbuphine, and butorphanol are the result of interference with adrenergic neurotransmission or are caused by direct depressant actions on venous smooth muscle cells. Morphine (5 X 10(-5) M and 2 X 10(-4) M) caused a dose-dependent depression of the contractile response to transmural electrical stimulation. H1- and H2- histamine antagonists did not attenuate the inhibitory effect of morphine. Concentrations of morphine and nalbuphine lower than 5 X 10(-5) M had no effect, whereas 5 X 10(-6) M butorphanol significantly depressed the evoked tension response to electrical stimulation. The contractile responses of the veins to exogenous norepinephrine (NE) were not altered by morphine, indicating a presynaptic site of action rather than a direct action on the venous smooth muscle. Transmural electrical stimulation was used to evoke release of endogenous NE. Morphine (5 X 10(-5) M and 2 X 10(-4) M), nalbuphine (2 X 10(-4) M), and butorphanol (4 X 10(-6) M) significantly decreased release of NE. Naloxone did not alter NE release and did not attenuate the inhibition of NE release observed with the opiates, indicating that the effect of morphine on this neuroeffector junction is not mediated by a naloxone-sensitive opiate receptor. Blockade of presynaptic alpha receptors by phenoxybenzamine or phentolamine augments NE release caused by transmural electrical stimulation; morphine inhibited this augmentation. The results of these experiments indicate that high concentrations of morphine may decrease NE release, an effect that may contribute to the venodilation and hypotension observed following administration of high doses of morphine in humans. In the usual analgesic doses, the venodilatory effects of morphine cannot be explained by local action on either NE release or venous smooth muscle contractility.

Adrenergic alpha-Antagonists↗
PubMed1981

Epidural morphine following epidural local anesthesia: effect on ventilatory and airway occlusion pressure responses to CO2.

The authors measured the minute inspired ventilation (VI) and airway occlusion pressure (P 100) responses to CO2 during rebreathing in ten patients who were given epidural morphine for analgesia following lower extremity or lower abdominal surgery. All patients were studied and blood samples for morphine analysis were obtained at four different times: preoperatively, postoperatively premorphine, and one and six hours after a single 10-mg epidural dose of preservative-free morphine in 10 ml of saline. All patients reported effective analgesia with a duration ranging from 8-25.5 h. There were no differences between the pre- and postoperative VI vs. PCO2 and P100 vs. PCO2 response slopes, indicating that the epidural local anesthetic alone had no effect on respiratory drive. Administration of 10 mg morphine epidurally caused a significant 22 per cent decrease in the average VI vs. PCO2 slope and a 33 per cent decrease in the average P100 vs. PCO2 slope one hour postmorphine when compared to the postoperative slopes. The average decrease in VI vs. PCO2 at 6 h postmorphine was not significant. The average P100 vs. PCO2 response slope was decreased significantly at 6 h postmorphine by 27 per cent. There was no significant correlation between serum morphine concentration and the ventilatory responses. The authors conclude that morphine administered by the epidural route produces decreased respiratory drive and that there is a high degree of individual variability in the magnitude and time course of this effect.

Adult↗
PubMed1979

Spontaneous-ventilation general anesthesia for outpatients using enflurane.

We have described our technique for general anesthesia for outpatients using a mixture of nitrous oxide, oxygen, and enflurane with spontaneous ventilation through a Bain anesthetic circuit. In our experience, surgical excision of impacted teeth, multiple extractions and alveoloplasty, enucleation of simple cysts, excision of benign tumors, and other similar operations have been done efficiently with these anesthetic techniques. More than 500 such cases have been managed without significant complication. The concepts of selection and preparation of patients, airway security and protection during surgery performed in the upper airway on an unconscious patient who is breathing spontaneously, continuous monitoring of vital functions, and rapid induction and recovery all combine to make this technique consistent with standards for excellence in anesthesia.

Ambulatory Care↗
PubMed1978

An evaluation of enflurane as an amnesic agent for outpatient oral surgery.

An alternative to general anesthesia for outpatient oral surgery that creates a state of cooperative amnesia without eliminating the patient's protective reflexes has been developed. Enflurane, 1.5%, administered via a nasal mask produced a high incidence of amnesia with all patients remaining cooperative, with protective reflexes intact.

Adolescent↗