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Biomedical subjects

C Byrne

Publications and source records attributed to C Byrne.

At least 145 records · Page 8Linked to original sources

A review of current approaches used to help children and parents cope with health care procedures.

There has been a long-standing belief that children and parents require preparation and support in the event of hospitalization. Programs that prepare children for hospitalization are designed to inform the child about what will happen and to familiarize the child with his environment. Although these programs provide only general information, they do impact upon the way a child can cope with specific procedures. Even though it is unclear why information is beneficial, there are reported studies that demonstrate its effectiveness. Information about health care procedures is provided through modelling, procedural, and sensory information, and stress-point nursing. While some of these techniques, as described in the literature, may be too extensive for every nurse to fully carry out with every child, the principles can be incorporated by all nurses. The studies cited give some indication that early preparation is beneficial for older children (7 years old and older), but that younger children benefit from preparation immediately prior to the procedure. Children with a previous hospital experience are thought to respond to information on rehospitalization in a unique way. Furthermore, while children may demonstrate anxiety initially when given certain kinds of information, stress-point nursing (repeated information and support) has been reported to be particularly beneficial. The research findings tend to oppose the notions that young children should not receive information, that all children benefit equally from the same type and timing of preparation, that a child who has had a previous experience requires less preparation, and that a one-time pre-admission program provides adequate preparation. The provision of emotional support and the use of play as a means of helping children cope with procedures is strongly supported in the anecdotal and theoretical literature. However, there are few controlled studies that have specifically analyzed the effects of play programs in pediatric settings. Studies done examining techniques that assist the child in gaining a sense of control suggest that a child can benefit from being helped to gain a sense of mastery over a stressful event. Progressive muscle relaxation and desensitization have been shown to reduce anxiety and discomfort during health care procedures. The effectiveness of these techniques, who can best use them, and when they should be used are questions still to be answered. The varying degrees of methodological rigor in present studies point to a need for further research. One cannot definitively state how closely nursing practice reflects available research findings as outlined in this article.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Psychological↗

Features of residual renal function in end-stage renal failure associated with spinal cord injury.

The characteristics of end-stage renal disease (ESRD) complicating spinal cord injury (SCI) were studied retrospectively in 43 male hemodialysis patients. A control group of male patients dialyzed in the same institution were studied for comparison. The SCI patients had significantly lower serum creatinine concentrations and daily urinary creatinine excretion than the control group, despite comparable creatinine clearances. Therefore, serum creatinine, when compared with the familiar values in non-SCI patients, may greatly underestimate the severity of the renal impairment. Urine output was higher, urine specific gravity lower, and renal glucosuria more common in the SCI patients. 24-hour urinary protein excretion was higher and serum albumin was lower in the SCI patients, with 48% of the patients exhibiting nephrotic range proteinuria. Urine pH was markedly elevated, and pyuria and bacteriuria were present in all SCI patients. Fractional excretion of potassium (159 +/- 16%) exceeded its filtered load in most SCI patients.

Adult↗

Prediction of creatinine clearance from serum creatinine in spinal cord injury patients.

Measured endogenous creatinine clearance (Ccr) was compared with the predicted Ccr in 22 paraplegic, 36 tetraplegic and 11 ambulatory male individuals as well as 11 ambulatory females all of whom had normal renal function. While the predicted and measured values closely matched in the ambulatory patients the predicted values in the spinal cord injured patients consistently exceeded the measured values. It thus appears that the original Cockcroft and Gault formula; (formula; see text) when applied to SCI patients can be misleading. Modification of the original formula using a correction factor of 0.8 in paraplegics and 0.6 in tetraplegics was found to allow prediction of Ccr from age, sex, body weight, and serum creatinine in these patients with reasonable accuracy.

Adult↗

Clinicopathological characteristics of dialysis patients with spinal cord injury.

Forty-three spinal cord injured patients with endstage renal disease (ESRD) maintained on hemodialysis were studied. The most prevalent renal lesions consisted of chronic pyelonephritis and amyloidosis while the main renal functional features included nephrotic range proteinuria, high urine output and relatively low serum creatinine for the degree of renal insufficiency. Normocytic, normochromic anemia with low reticulocyte response, low serum iron and iron binding capacity and high transfusion requirement and serum ferritin were noted. Various cardiovascular, pulmonary and gastrointestinal abnormalities were found with considerable frequencies. The incidence of amyloidosis was much higher than that reported previously. This is thought to be due to continued progression of amyloidosis occasioned by longer survival in the present series.

Adult↗

The effects of oral digoxin therapy in primary mitral leaflet prolapse.

The effects of oral digoxin on symptoms, arrhythmias, exercise tolerance and echocardiographic function in primary mitral leaflet prolapse were studied in 23 patients using a double-blind crossover protocol. Digoxin reduced the incidence and severity of chest pain compared with both the control (P = 0.0002) and placebo (P = 0.0005) periods. We found a high (83%) incidence of predominantly minor arrhythmias on continuous ambulatory monitoring. Digoxin favourably affected the incidence of frequent supraventricular ectopic beats and supraventricular tachycardia but was associated with a significant number (P less than 0.0025) of asymptomatic bradyarrhythmias. In patients with frequent ventricular ectopics, digoxin had no consistent effect. No difference in exercise tolerance between treatment periods was found on maximal treadmill stress testing, but digoxin administration resulted in an increase in echocardiographic mean circumferential fibre shortening velocity (P less than 0.01) and fractional shortening percent (P less than 0.01). This study demonstrates the efficacy of oral digoxin therapy in ameliorating chest pain in patients with primary mitral leaflet prolapse and suggests a favourable effect on supraventricular arrhythmias in such patients.

Administration, Oral↗

Lipid fractions in primary hyperparathyroidism before and after surgical cure.

A number of previous studies has suggested that PTH may possess a hyperlipimic property. We determined various lipid fractions in 24 patients with primary hyperparathyroidism before and 1-3 months after surgical cure. The mean values for serum total cholesterol, triglycerides. LDL-Chol, VLDL-Chol and HDL-Chol did not change significantly with definitive correction of hyperparathyroidism. The mean values for all lipid fractions were comparable to those of the age- and and sex-matched normal control group except for HDL-Chol which was significantly lower in the hyperparathyroid group both before and after definitive cure of hyperparathyroidism. Only one patient with combined elevation of serum triglycerides and cholesterol exhibited normalization of the lipid levels after surgery. Two other patients with hypertriglyceridaemia failed to show any reduction in their triglyceride levels after correction of their hyperparathyroidism. Our data suggest that longstanding elevation of PTH to the extent seen in primary hyperparathyroidism and in the absence of predisposing conditions does not increase serum lipids in human.

Adult↗

Hematologic features of chronic renal failure associated with spinal cord injury.

We examined the available hematologic data on 43 spinal cord injury (SCI) patients with end-stage renal disease (ESRD) treated with hemodialysis since 1972. A control group consisting of 45 ESRD patients without SCI was included for comparison. Moderate to severe anemia was found in all patients. The observed anemia was generally normocytic, normochromic, and associated with a low reticulocyte response. Transfusion requirement in the SCI group was considerably more than in the control group. There was a high incidence of splenomegaly, splenic amyloidosis, and lymph node enlargement in the SCI group. Lymph node and bone marrow amyloid deposits were found in some SCI patients but not in the control subjects.

Adult↗

Bacterial infections in patients with chronic renal failure: occurrence with spinal cord injury.

The available data were examined from 43 patients with spinal cord injuries and end-stage renal disease undergoing dialysis. All but one patient had a chronic urinary tract infection, which was characterized by persistence of the same organisms for prolonged periods, high prevalence of mixed infections, scarcity of symptoms, lack of fever of leukocytosis, and a considerable prevalence of cross-infection with the decubitus ulcers. Staphylococcus aureus and various Gram-negative organisms were responsible for most of the vascular access infections in our patients. Decubitus ulcers were common and were frequently infected. Cross-contamination between infected decubitus ulcers, the urinary tract, and vascular access seemed to have occurred on several occasions. The recorded respiratory infections were preponderantly caused by Gram-negative organisms. Urinary tract, vascular access, and decubitus infections seemed to be the source of septicemia in most of the recorded instances. Septicemia was the immediate cause of death in half of the patients.

Adult↗

The effects of chronic oral cimetidine therapy on the cardiovascular system in man.

1 The demonstration of histamine (H2) receptors in the cardiovascular system in man and the widespread use of the specific H2 receptor antagonist cimetidine for the treatment of peptic ulcer has necessitated assessment of the cardiovascular effects of this drug during oral therapy in man. 2 Consequently, nineteen patients with a history of peptic ulcer but in symptomatic remission underwent a double-blind crossover trial of oral cimetidine v placebo, each treatment period lasting 4 weeks. No significant difference in various cardiac parameters at rest (heart rate, blood pressure, ECG) or following a maximal treadmill exercise test (time-into-protocol, maximum heart rate and blood pressure) was found between the groups. Similarly, cimetidine produced no change in the incidence of ventricular ectopics or in heart rate on 24 h ambulatory monitoring and had no effect on left ventricular volume or contractility as measured by echocardiography. 3 Thus oral administration of cimetidine in a dose of 400 mg four times daily was associated with no demonstrable cardiovascular changes. In addition, since this dose is thought compatible with cardiovascular H2 receptor blockade this study favours the lack of a physiological role for these receptors in man.

Cardiovascular Diseases↗

Ineffectiveness of intravenous ascorbic acid as an acidifying agent in man.

The acidifying effect of intravenous (IV) ascorbic acid was studied in seven healthy adult volunteers. After obtaining baseline urine and blood samples, 2-g IV doses of ascorbic acid were administered to each subject during a 20-minute period. Venous blood samples were obtained at times 0.5, 1, and 2 hours, and urine was collected at times 0.5, 1, 2, and 3 hours. Our results show that venous blood pH, plasma bicarbonate concentration, urine PCO2, and urine bicarbonate excretion did not change significantly during the study period. Urinary titratable acidity, ammonium excretion, and net hydrogen ion excretion decreased, and urinary pH actually showed a significant rise at two hours. We therefore conclude that IV ascorbic acid administered in recommended doses does not effectively acidify urine.

Acid-Base Equilibrium↗

Assessment of prognostic factors in patients undergoing surgery for non-rheumatic mitral regurgitation.

Twenty-four patients who had undegone mitral valve surgery for pure non-rheumatic mitral regurgitation were studied non-invasively six months to six years postoperatively. The long-term results of operation were assessed on the basis of clinical history, echocardiography, and treadmill stress testing using a points scoring system. The score so obtained was used to divide the patients into those with a good response to surgery (group 1) and those responding poorly (group 2). The effects on the long-term surgical outcome of several intraoperative and preoperative factors were then analysed both together and separately. A short symptomatic history (less than 1 year), a normal left ventricular end-diastolic volume index (less than or equal to 100 ml per m2), and a large post-ectopic potentiation of KV max (greater than 50 s-1) were found to be favourable prognostic factors when analysed independently. An angiographic ejection fraction less than 0.5 was uniformly associated with a poor outcome, and 71 per cent of patients in atrial fibrillation at the time of operation also responded badly. In those patients with good long-term function, cold potassium cardioplegia was more commonly used than intermittent aortic cross clamping as the means of intraoperative myocardial preservation, though this difference did not reach conventional significance. A standard analysis of variance allowed assessment of length of history, left ventricular end-diastolic volume index, and type of valve prosthesis simultaneously. This indicated that both length of history and left ventricular end-diastolic volume index were highly significant prognostic factors. The use of a Björk-Shiley as opposed to a Starr-Edwards prosthesis also emerged as significantly favouring a good long-term result. The state of the left ventricular myocardium before operation and the type of valve prosthesis used were thus shown to be the prime determinants of surgical outcome in these patients. The optimum time for operation was shown to be within one year of the onset of symptoms, and before the left left ventricular end-diastolic volume index exceeds 100 ml per m2, or the ejection fraction falls to less than 0.5. At such a time, irreversible changes in myocardial function sufficient to negate the beneficial effects of mitral valve surgery have not yet occurred.

Angiocardiography↗

Preservation of urinary postprandial alkaline tide despite inhibition of gastric acid secretion.

Ingestion of food leads to a rise in urinary pH. This phenomenon is commonly known as "postprandial alkaline tide" and is generally attributed to acid secretion in the stomach. To examine this hypothesis, we studied the changes of urinary pH, H+ concentration, PCO2, and bicarbonate in nine healthy volunteers with and without histamine H2 receptor blockade, using cimetidine and placebo medication. Postprandial alkaline tide persisted and was even exaggerated during treatment with cimetidine. Preservation of postprandial urinary alkaline tide, despite the expected inhibition of gastric acid secretion by cimetidine, tends to exclude a causal relation between alkaline tide and gastric acid secretion.

Acid-Base Equilibrium↗

An approach to estimating exposure-specific rates of breast cancer from a two-stage case-control study within a cohort.

The Breast Cancer Detection and Demonstration Project (BCDDP) included a large cohort of women followed for incidence of breast cancer and from whom an initial case-control sample was drawn and standard risk factors obtained. In order to study the effect of mammographic features on breast cancer risk, a nested subsample of cases and controls was drawn. Therefore, these data can be viewed as two-stage case-control data within a cohort, or as cohort data with two nested levels of missingness, since basic characteristics like age were measured on all members of the cohort, standard risk factors were elicited only in the initial case-control sample, and mammographic features were assessed only in the nested subsample of cases and controls. We present a Poisson pseudo-likelihood approach to estimating age- and exposure-specific breast cancer incidence rates based on the three types of variables. This approach takes into account the nested missingness as well as two other type of missingness namely, that for basic variables and standard risk factors, some levels (i) were omitted by design in the nested subsample of case and controls or (ii) were empty because of the sparsity of the data in that subsample. Estimates of standard errors are obtained from a parametric bootstrap. The approach seems to be efficient when applied to the BCDDP data and is flexible for modelling breast cancer rates and taking the special missingness features of these data into account.

Adult↗

Efficacy of a new quarternary ammonium compound against TB.

Ten of 12 strains of Mycobacteria (11 M. tuberculosis, 1 M. bovis) including 7 resistant strains were found to be sensitive to tetradecyl-dimethyl-benzyl-ammonium fluoride (TDBAF) at a concentration of 15-7.75 micrograms/ml (end point 10 micrograms/ml). A single multi-resistant strain of M. tuberculosis and a culture of M. bovis were also sensitive but at a slightly higher level.

Antitubercular Agents↗

Facilitating empowerment groups: dismantling professional boundaries.

The purpose of this study was to identify the issues and the process faced by public health nurses facilitating empowerment groups with people with a chronic and persistent mental illness. Five public health nurses facilitated seven groups which met weekly for a period of one year. Nurses kept field notes following each group session and methods of grounded theory were used to develop an understanding of the process of facilitating empowerment groups. A process of dismantling professional boundaries was identified which included three dimensions: experiencing the clash of worlds; joining the lives of people with a mental illness; and an exploration of professional self. The results highlight the need to challenge traditional ways of practicing.

Chronic Disease↗

Adult psychosocial adjustment following childhood injury: the effect of disfigurement.

The literature investigating the psychosocial adjustment of burn survivors is limited and that addressing such adjustment in burned children is contradictory. Forty-two adults, burned in childhood, were assembled into burn severity cohorts and compared as to burn severity, intensity of stress, and extent of disfigurement and disability. The findings substantiated the hypothesis that the biologic variables of years since burn and severity would not explain psychosocial adjustment in adulthood; lower adjustment correlated with visible disfigurement and less peer support rather than with severity of burn.

Adaptation, Psychological↗