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Biomedical subjects

A M Keenan

Publications and source records attributed to A M Keenan.

At least 19 recordsLinked to original sources
PubMed2002

Effect of rescuer fatigue on performance of continuous external chest compressions over 3 min.

Guidelines for the performance of cardiopulmonary resuscitation (CPR) have been revised recently and now advocate that chest compressions are performed without interruption for 3 min in patients during asystole and pulseless electrical activity. The aim of the present study was to determine if rescuer fatigue occurs during 3 min of chest compressions and if so, the effects on the rate and quality of compressions. Forty subjects competent in basic life support (BLS) were studied. They performed continuous chest compressions on a Laerdal Skillmeter Resusci-Anne manikin for two consecutive periods of 3 min separated by 30 s. The total number of compressions attempted was well maintained at approximately 100 min(-1) throughout the period of study. However, the number of satisfactory chest compressions performed decreased progressively during resuscitation (P < 0.001) as follows: first min, 82 min(-1); second, 68 min(-1); third, 52 min(-1); fourth, 70 min(-1); fifth, 44 min(-1); sixth, 27 min(-1). We observed significant correlations between the number of satisfactory compressions performed and both height and weight of the rescuer. Female subjects achieved significantly fewer satisfactory compressions compared with males (P = 0.03). Seven subjects (five female, two male) were unable to complete the second 3-min period because of exhaustion. We conclude that rescuer fatigue adversely affects the quality of chest compressions when performed without interruption over a 3-min period and that this effect may be greater in females due to their smaller stature. Consideration should be given to rotating the rescuer performing chest compressions after 1 min intervals.

Adult↗
PubMed2001

Inter-segment foot motion and ground reaction forces over the stance phase of walking.

OBJECTIVE: To compare the magnitude and patterns of motion of the rearfoot segment relative to the leg, forefoot segment relative to the rearfoot, height change in the medial longitudinal arch and ground reaction forces of normal adult males during the stance phase of walking. BACKGROUND: Knowledge of normal motion of the rearfoot and forefoot segments and of the arch during stance phase is important in clinical management. METHODS: Motion data were obtained from surface markers, and force data from a force plate, from the right limb of participants while walking at a self-selected pace. RESULTS: Stance phase range of motion across sagittal, frontal and transverse planes was 12 degrees, 4 degrees and 10 degrees for the forefoot, compared to 22 degrees, 8 degrees and 10 degrees for the rearfoot. Most motion occurred at the beginning and end of stance phase when support was via only the rearfoot or forefoot, and when forces were maximal. Arch height decreased from heel contact and increased after heel rise to its maximum at toe-off. CONCLUSIONS: The extent of forefoot segment motion confirms the significance of midfoot joints to normal foot function. Between foot flat and heel rise, the forefoot pattern of motion is indicative of foot stability. Typical foot motion does not obey descriptions of triplanar motion such as 'pronation' and 'supination'. RELEVANCE: Typical stance phase foot motion has been described according to a forefoot:rearfoot model and rearfoot:leg model of motion, together with profiles of medial longitudinal arch height and ground reaction forces. This information can be applied in the management of foot dysfunction and should stimulate research into midfoot motion and overall control of the foot.

Adult↗
PubMed2001

Foot orthosis prescription habits of Australian and New Zealand podiatric physicians.

This research project investigated the orthotic prescription habits of podiatric physicians in Australia and New Zealand. A 23-item questionnaire was distributed to all members of the Australian Podiatry Association and the New Zealand Society of Podiatrists. When asked what type of foot orthoses they prescribe most often, 72% of respondents reported functional foot orthoses; the next most common response was prefabricated orthoses (12%). A typical prescription for functional foot orthoses consisted of a modified Root style orthosis, balanced to the neutral calcaneal stance position, with the shell made from polypropylene and an ethyl vinyl acetate (EVA) rearfoot post applied. The majority of podiatric physicians surveyed used a commercial orthotic laboratory to fabricate their orthoses. However, New Zealand respondents were three times more likely to prescribe prefabricated foot orthoses, and males were twice as likely as females to manufacture the orthoses themselves rather than use a commercial orthotic laboratory.

Australia↗
PubMed2001

Wound healing and infection in nail matrix phenolization wounds. Does topical medication make a difference?

After nail matrix ablation using phenolization, a medicated wound dressing (10% povidone iodine), an amorphous hydrogel dressing (Intrasite Gel), and a control dressing (paraffin gauze) were evaluated. Forty-two participants, randomly divided into three dressing groups, were evaluated. Healing time did not differ between the 10% povidone iodine (33 days), amorphous hydrogel (33 days), and the control dressing (34 days). For all groups, the clinical infection rate was lower than in previous studies, and there was no clinical difference between groups (one infection in the povidone iodine and control groups; none in the amorphous hydrogel group). However, in the amorphous hydrogel group, other complications, such as hypergranulation, were more likely. This investigation indicated that medicated or hydrogel dressings did not enhance the rate of healing or decrease infection rates.

Adult↗
PubMed2001

The effect of high-Dye and low-Dye taping on rearfoot motion.

High-Dye and low-Dye taping are commonly used by clinicians to treat a variety of foot and ankle pathologies, particularly those associated with excessive rearfoot pronation. While the effects of taping on end range of motion have been extensively studied, relatively little is understood about the effect of the two styles of taping on rearfoot motion. Eighteen participants were analyzed in three conditions: 1) barefoot, 2) with high-Dye taping, and 3) with low-Dye taping. Two-dimensional motion of the rearfoot was assessed for each condition. The results indicated maximum inversion was increased with both high-Dye and low-Dye taping as compared with no taping. Only high-Dye taping, however, significantly reduced the maximum eversion of the rearfoot. The results suggest that high-Dye taping is an appropriate taping choice when control of eversion of the rearfoot is desired.

Ankle↗
PubMed2000

Efficacy of foot orthoses. What does the literature tell us?

This paper reviews the literature relating to foot orthoses, in particular foot orthoses that attempt to alter biomechanical function. Whilst few well-controlled studies have been performed, the findings from the available literature are generally positive. The authors provide an overview of this literature and then summarise the findings. The literature is categorised into six research outcome areas: (i) patient satisfaction, (ii) pain and deformity, (iii) plantar pressures, (iv) position and motion, (v) muscle activity, and (vi) oxygen consumption. In addition, the difficulties associated with researching foot orthoses are discussed.

Biomechanical Phenomena↗
PubMed1999

Syndrome of inappropriate secretion of antidiuretic hormone in malignancy.

OBJECTIVES: To provide a review of pathophysiology, epidemiology, signs and symptoms, diagnosis, treatment, and nursing management of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in malignancy. DATA SOURCES: Research reports, review articles, and book chapters relevant to SIADH. CONCLUSIONS: The principle cause of hyponatremia in malignancy is SIADH. Early recognition and prompt treatment can prevent serious neurologic sequelae. Antineoplastic therapy and methods to correct hyponatremia constitute effective treatment strategies. IMPLICATIONS FOR NURSING PRACTICE: Nurses play a major role in nursing assessment, appropriate interventions and symptom control, and promoting resolution of problems and optimal quality of life in patients with malignancy complicated by SIADH.

Carcinoma, Neuroendocrine↗
PubMed1999

Lithium as a potential adjuvant to 131I therapy of metastatic, well differentiated thyroid carcinoma.

As lithium inhibits the release of iodine from the thyroid but does not change iodine uptake, it may potentiate 131I therapy of thyroid cancer. The effects of lithium on the accumulation and retention of 131I in metastatic lesions and thyroid remnants were evaluated in 15 patients with differentiated thyroid carcinoma. Two 131I turnover studies were performed while the patients were hypothyroid. One was performed while the patient received lithium; the second served as a control study. From a series of gamma-camera images, it was found that lithium increased 131I retention in 24 of 31 metastatic lesions and in 6 of 7 thyroid remnants. A comparison of 131I retention during lithium with that during the control period showed that the mean increase in the biological or retention half-life was 50% in tumors and 90% in remnants. This increase occurred in at least 1 lesion in each patient and was proportionally greater in lesions with poor 131I retention. When the control biological half life was less than 3 days, lithium prolonged the effective half-life, which combines both biological turnover and isotope decay, in responding metastases by more than 50%. More 131I also accumulated during lithium therapy, probably as a consequence of its effect on iodine release. The increase in the accumulated 131I and the lengthening of the effective half-life combined to increase the estimated 131I radiation dose in metastatic tumor by 2.29 +/- 0.58 (mean +/- SEM) times. These studies suggest that lithium may be a useful adjuvant for 131I therapy of thyroid cancer, augmenting both the accumulation and retention of 131I in lesions.

Adult↗
PubMed1996

Video assessment of rearfoot movements during walking: a reliability study.

OBJECTIVE: Rearfoot motion, particularly rearfoot pronation, has been associated with many foot and leg pathologies. The assessment of abnormal rearfoot pronation frequently involves the use of video assessment in both clinical and research settings, but the reliability of this assessment has not been addressed. DESIGN: In this study, 14 participants were videotaped during walking. Five clinicians individually viewed the recordings on two separate occasions and assessed whether the participant's rearfoot motion was abnormal. SETTING: University Gait Analysis Laboratory. PATIENTS OR OTHER PARTICIPANTS: Patients from the university's podiatry clinic were assessed for rearfoot motion by five experienced clinicians. INTERVENTION: Because this was a reliability study, no intervention was undertaken. MAIN OUTCOME MEASURES: Clinicians were asked to assess the videotape of the patients walking and indicate on a 3-point scale if they considered the person to be abnormally pronating. Retest and intertester results were compared. RESULTS: The results indicated that there was poor intertester agreement (kappa = .19). Retest agreement, while slightly higher, varied from poor to fair (kappa = -.12 to kappa = 59). CONCLUSIONS: Although video recordings have been thought to enhance reliability of assessment of rearfoot motion, the results indicated that the exclusive use of video recordings in the assessment of motion of the rearfoot was not reliable.

Adult↗
PubMed1996

Blanket use of intranasal mupirocin for outbreak control and long-term prophylaxis of endemic methicillin-resistant Staphylococcus aureus in an open ward.

In December 1992, a thoracic ward in a Melbourne teaching hospital experienced an increase in patients infected with methicillin-resistant Staphylococcus aureus (MRSA). It was decided to attempt to control the outbreak by cohorting positive patients (infected and colonized), as well as nurse cohorting, emphasis on handwashing, and use of intranasal mupirocin initially three times a day for three days, then thrice weekly, for all patients in the ward (with or without MRSA). The campaign comprised for phases of 53, 45, 92 and 365 days, respectively. Patient and nurse cohorting stopped at the end of phase I. In phases I and II, surveillance nose swabs were taken on admission, then twice weekly; in phase III, on admission and weekly and in phase IV, on admission until the end of 1993. In phases I and II (98 days), only one patient acquired MRSA. When the frequency of mupirocin prophylaxis was decreased to once weekly (phase III), two patients acquired MRSA in 92 days (no significant difference): thrice weekly administration resumed (phase IV), during which there were three acquisitions in 365 days. The rates of nose colonization of admissions were 6.4%, 6.3%, 9.7% and 3.1% in phase I-IV, respectively. Only three patients were treated with vancomycin between July 1993 and June 1994 (significantly lower than historical rates, P = 0.0086). No mupirocin resistance was seen in MRSA isolates from this ward during phases I, II and III. In areas of low-level endemic MRSA, the blanket use of thrice-weekly intranasal mupirocin may be effective in decreasing serious infections with MRSA, and does not necessarily elicit mupirocin resistance.

Administration, Intranasal↗
PubMed1996

Aspirin and warfarin for thromboembolic disease after total joint arthroplasty.

This study compares the benefits of aspirin and warfarin prophylactic agents for patients with thromboembolic disease after total joint arthroplasty. It is a prospective randomized study of 388 patients having total hip or total knee surgery. All consecutive patients having total hip or total knee surgery were entered into this study and evaluated with preoperative and postoperative ventilation perfusion scans and a postoperative venogram. The aspirin and warfarin treatment groups were compared by size and location of venographically revealed clots and changes in ventilation perfusion scans. The results showed that there was no difference in the size or location of deep venous thrombosis in the aspirin or warfarin treatment groups. The venogram was negative in 44.5% of patients; 28.8% had small ++calf clots, 16% had large calf clots, 3.9% had popliteal clots, and 6.7% had femoral clots. Patients with total knee replacement had a 2.6 times greater incidence of calf deep venous thrombosis than patients with total hip replacement. There was no difference between the aspirin and warfarin groups in the incidence of changes in ventilation perfusion scans (18.9%). There was no difference between the 2 groups in bleeding complications. The results suggest that aspirin and warfarin are equivalent in prophylaxis against thromboembolic disease, as determined by prevention of venographic changes or changes in ventilation perfusion scans.

Aged↗
PubMed1992

Nuclear medicine in the diagnosis of deep venous thrombosis and pulmonary embolism.

Nuclear medicine techniques offer a variety of approaches to the diagnosis of deep venous thrombosis and pulmonary embolism. Several radionuclide methods are available to visualize venous structures, and many radiolabeled agents have been developed for direct visualization of blood clots, including platelets and monoclonal antibodies. Although still available on a limited basis, radiolabeled fibrinogen uptake studies have been replaced largely by newer methods. Ventilation-perfusion lung scanning remains the mainstay of nuclear medicine detection of pulmonary embolism as it has for the past two decades.

Humans↗
PubMed1991

Direct intralymphatic injection of radiolabeled 111In-T101 in patients with cutaneous T-cell lymphoma.

Direct intralymphatic administration of radiolabeled monoclonal antibody in targeting antigen-bearing lymphoma cells in regional lymph nodes of patients with cutaneous T-cell lymphoma was evaluated. Seven consecutive patients undergoing staging lymphangiography received intralymphatic infusions of 111In-T101 to evaluate lymph node involvement. This procedure was accomplished without significant complication. The 111In-T101 rapidly distributed throughout the regional lymphatic compartment and passed into the systemic circulation. Tumor-bearing sites in the inguinal-femoral lymph nodes retained from 0.42 to 4.8% of the injected dose of radiolabeled antibody. Three patients were upstaged to Stage IVA based on tumor involvement found after radiolymphoscintigraphy-directed biopsy of groin lymph nodes, selected because of intense radioactivity by gamma camera imaging. Compared with previously reported s.c. antibody administration, there was a marked reduction in the radioactive exposure of normal tissues at the injection sites in the lower extremities. Direct intralymphatic delivery of 111In-T101 appears to be a feasible, efficient method for delivering therapeutic doses of radiolabeled antibody.

Adult↗
PubMed1991

An evaluation of preoperative and postoperative ventilation and perfusion lung scintigraphy in the screening for pulmonary embolism after elective orthopedic surgery.

One hundred two patients undergoing elective knee or hip arthroplasty were studied with radionuclide ventilation scans (V) and perfusion scans (Q) preoperatively (preop) and postoperatively (postop) to assess their relative value in the diagnosis of asymptomatic pulmonary embolism (PE) after orthopedic surgery. Postop Q were read in combination with preop V and Q and postop V using prospective investigation of pulmonary embolism diagnosis (PIOPED) criteria. Of 25 postop Q interpreted as either high or intermediate probability for PE, preop Q were judged useful in 96%; the postop V were useful in 78%; and the preop V were not helpful in any of the cases. Of 63 postop Q interpreted as low probability, preop Q were useful in 74%; the postop V were useful in only 33%; and the preop V were useful in only one case. When postop Q were read as normal (14 cases), none of the three auxiliary studies were found to be useful. Overall, postop V were more helpful than preop Q in only 2%, and preop V contributed significantly in only 1%. This experience suggests that preop Q alone is the most useful adjunct to the postop Q in the postoperative evaluation for PE. The authors conclude that to screen for asymptomatic PE after elective orthopedic surgery, preop Q should be performed in all cases, preop V are not necessary, and postop V need be performed only if a baseline preop Q is not available.

Aged↗
PubMed1990

In vivo traffic of indium-111-oxine labeled human lymphocytes collected by automated apheresis.

The in vivo traffic patterns of autologous lymphocytes were studied in five normal human volunteers using lymphocytes obtained by automated apheresis, separated on Ficoll-Hypaque gradients, and labeled ex vivo with 111In-oxine. Final lymphocyte infusions contained 1.8-3.1 X 10(9) cells and 270-390 microCi (9.99-14.43 MBq) 111In, or 11-17 microCi (0.41-0.63 MBq) per 10(8) lymphocytes. Gamma imaging showed transient lung uptake and significant retention of radioactivity in the liver and spleen. Progressive uptake of activity in normal, nonpalpable axillary and inguinal lymph nodes was seen from 24 to 96 hr. Accumulation of radioactivity also was demonstrated at the forearm skin test site, as well as in its associated epitrochlear and axillary lymph nodes, in a subject who had been tested for delayed hypersensitivity with tetanus toxoid. Indium-111-oxine labeled human lymphocytes may provide a useful tool for future studies of normal and abnormal lymphocyte traffic.

Blood Component Removal↗
PubMed1989

Immunolymphoscintigraphy.

Immunolymphoscintigraphy (ILS) refers to lymphatic administration of radiolabeled antibodies for lymph node imaging. Macromolecules such as immunoglobulins are preferentially taken up by lymphatic vessels rather than venous capillaries following interstitial injection. They then travel to regional nodes by lymph flow where they can interact with tumor cells, lymphocytes, or macrophages residing within the node. A variety of radiolabeled antibodies and their fragments have been studied, both in animals and humans, to test their ability to selectively target cells in lymph nodes. Preliminary clinical trials in patients with lymphoma, melanoma, and breast cancer suggest that immunolymphoscintigraphy holds great potential for accurate staging of early malignant disease. The procedure is safe and simple to perform, and offers a noninvasive means to detect small deposits of tumor in regional lymph nodes. Furthermore, direct intralymphatic administration results in even more efficient delivery of immunospecific agents, raising the possibility of radiotherapy by this route.

Animals↗