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P J Osmundson

Publications and source records attributed to P J Osmundson.

At least 19 recordsLinked to original sources
PubMed1992

Exercise strain-gauge venous plethysmography: evaluation of a "new" device for assessing lower limb venous incompetence.

Plethysmography can be used to detect and assess venous incompetence in the lower extremities. The authors recently evaluated a new device designed for this purpose that uses strain gauges to determine changes in lower extremity circumference occurring with (and immediately after) exercise. The device plots a curve of volume against time for each limb and automatically calculates key values such as the volume of blood expelled from the lower limb veins during exercise and the time required for the veins to refill following exercise. The apparatus was incorporated into their noninvasive vascular laboratory and used (along with other standard tests) to study patients referred for suspected venous incompetence. They observed the following: (1) A shortened postexercise refilling time accurately identified limbs with venous incompetence. (2) The clinical severity of venous incompetence was inversely related to the refilling time. (3) Exercise-induced changes in lower extremity volume correlated well with simultaneously determined changes in venous pressure. (4) Valvular incompetence could be localized to the deep or superficial veins based upon the improvement in refilling times seen following placement of elastic tourniquets around the lower limb. (5) The type of exercise performed (knee bends while the patient was standing versus ankle reflexes while sitting) had little effect on results. The authors conclude that exercise venous plethysmography is a useful noninvasive tool for assessing lower limb venous incompetence.

Blood Volume↗
PubMed1992

Predictive value of transcutaneous oxygen pressure and amputation success by use of supine and elevation measurements.

The purpose of this study was to determine if transcutaneous oxygen pressure (tcPO2) measurements can be used to predict amputation site healing in lower limbs with arterial occlusive disease. We measured tcPO2 (supine and with limb elevation) in 90 limbs before amputation and reviewed their subsequent clinical course. Of these, 52 (57%) successfully healed, 21 (23%) failed, and 17 (18%) exhibited delayed healing. Limbs with delayed healing or failure had significantly lower tcPO2 values than values of those that healed. A tcPO2 greater than or equal to 40 torr was associated with primary or delayed healing in 51 of 52 limbs (98%), and a tcPO2 value of less than 20 torr was universally associated with failure. For patients with a tcPO2 between 20 and 40 torr, tcPO2 measurements obtained during limb elevation improved the predictability of outcome. We conclude that supine tcPO2 measurements can help predict amputation site healing, and that tcPO2 measurement during limb elevation improves predictability in limbs with borderline supine tcPO2 values.

Adult↗
PubMed1991

Progression of peripheral occlusive arterial disease in diabetes mellitus. What factors are predictive?

The clinical, biochemical, and vascular laboratory measurements potentially associated with the development and/or progression of peripheral occlusive arterial disease (POAD) were assessed during a 4-year period in 110 normal control subjects, 112 patients with POAD without diabetes mellitus, 240 patients with diabetes mellitus without POAD, and 100 patients with diabetes mellitus and POAD. Age, history of hypertension or coronary heart disease, history of cigarette smoking, presence of POAD, systolic blood pressure, and beta-thromboglobulin level were associated with progression of POAD. A multivariate logistic regression model indicated that the presence of diabetes mellitus or POAD or both at baseline, decreased postexercise ankle-brachial index, increased arm systolic blood pressure, and current smoking were independently associated with progression of POAD. This study suggests that cessation of smoking and control of hypertension are essential treatment modifications to decrease the risk of progression of peripheral vascular disease in diabetic patients.

Arterial Occlusive Diseases↗
PubMed1990

Effects of recombinant human erythropoietin on cerebral and cutaneous blood flow and on blood coagulability.

Seizures, hypertensive encephalopathy, transient ischemic attacks, and thrombosis of hemodialysis accesses occurred in early clinical trials with recombinant human erythropoietin. To determine if these events may be caused by the increased hematocrit value or some direct effect of the recombinant human hormone, 10 transfusion-dependent hemodialysis patients were divided into two groups of five according to their serum ferritin concentration: group A. less than 800 microgram/liter, and group B. greater than 800 micrograms/liter. After a month of placebo administration, recombinant human erythropoietin was given (150 U/kg intravenously thrice weekly) for four months and then stopped for one month. Hematocrit values were maintained at 0.33 +/- 0.02 (mean +/- SD) by dose adjustment in group A and at 0.26 +/- 0.02 by thrice weekly phlebotomies in group B, who received a constant dose of erythropoietin. Viscosity increased from subnormal to normal in group A (P less than 0.02) and cerebral blood flow decreased from above normal to normal (P less than 0.02). In group B minor, statistically insignificant, changes in viscosity and reciprocal changes in cerebral blood flow also occurred. There was no change in either group in transcutaneous oxygen tension. Bleeding time decreased toward normal in both groups during recombinant human erythropoietin administration but the changes did not reach statistical significance. Fibrinogen levels were increased in all patients but remained unchanged. No other significant coagulation-related changes were observed. Recombinant erythropoietin in the dosage and schedule of administration described in this study did not lead directly or indirectly to changes likely to precipitate seizures or intravascular thrombosis.

Anemia↗
PubMed1990

Sex differences in control of cutaneous blood flow.

Women are far more likely than men to suffer from Raynaud's disease. The purpose of this study was to determine whether there are gender differences in local or central control of cutaneous blood flow that could account for the increased incidence of Raynaud's disease in women. To assess cutaneous blood flow, hand blood flow (HBF), finger blood flow (FBF), or skin perfusion (SP) was measured by fluid plethysmography, mercury strain-gauge plethysmography, or laser Doppler spectroscopy, respectively, in 47 volunteers. Basal HBF in men exceeded that of women (12.1 +/- 2.0 versus 6.2 +/- 1.5 ml/100 ml/min). Likewise, FBF in men surpassed that of women (19.5 +/- 4.1 versus 7.7 +/- 1.8 ml/100 ml/min). Similarly, SP in men was greater than that of women (270 +/- 42 versus 81 +/- 16 perfusion units). However, after total body warming (to induce a thermal sympatholysis), HBF in women exceeded that of men, suggesting that the lower basal HBF in women was due to increased sympathetic outflow to the extremities. Mental stress and deep inspiration reduced HBF and SP in men. Paradoxically, both of these maneuvers increased HBF and SP in women. To determine whether these paradoxical responses in women were due to the women's elevated basal sympathetic tone, these experiments were repeated after total body cooling in men to increase sympathetic tone and after total body warming in women to reduce sympathetic tone. Total body cooling reduced HBF and SP in men. Under these conditions, mental stress and deep inspiration induced vasodilation. In women, total body warming for 10 minutes increased HBF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Course of peripheral occlusive arterial disease in diabetes. Vascular laboratory assessment.

To determine comparative rates of development and progression of peripheral occlusive arterial disease, 110 healthy nondiabetic control subjects, 112 patients with peripheral occlusive arterial disease (POAD), 240 patients with diabetes mellitus (DM), and 100 patients with diabetes mellitus and peripheral occlusive arterial disease (DM + POAD) were studied over 4 yr with noninvasive techniques. The presence of peripheral occlusive arterial disease was determined by postexercise ankle-brachial index (ABI) values; progression of peripheral occlusive arterial disease was determined by the rate of change in postexercise ABI. Patients who underwent peripheral arterial reconstructive surgery or amputation were also classified as having progression of their peripheral occlusive arterial disease. On this basis, follow-up revealed that peripheral occlusive arterial disease developed and therefore progressed in 1 (1%) of the control group and 22 (9%) of the DM. Peripheral occlusive arterial disease progressed in 31 (28%) of the POAD and 26 (26%) of the DM + POAD. The presence of peripheral occlusive arterial disease predisposes to progression of disease, and peripheral occlusive arterial disease is more likely to develop in diabetic patients who do not have peripheral occlusive arterial disease than in nondiabetic control subjects. However, the presence of diabetes mellitus in patients with peripheral occlusive arterial disease does not seem to increase the risk of progression.

Amputation, Surgical↗
PubMed1990

The influence of age, sex, smoking, and diabetes on lower limb transcutaneous oxygen tension in patients with arterial occlusive disease.

A retrospective study involving 129 patients (256 limbs) with unilateral or bilateral arterial occlusive disease was performed to assess the effects of age, sex, smoking, and diabetes on lower limb transcutaneous oxygen tension (TcPo2) measurements of were made according to a standard protocol, and the severity of lower limb arterial occlusive disease was estimated using the clinical signs and symptoms of disease or the ankle/brachial blood pressure index. The results demonstrated that age, sex, and smoking had no major effects on limb TcPo2 or disease severity; however, both limb TcPo2 and clinical disease severity were adversely affected by diabetes. When limbs with similar occlusive disease severity were compared, TcPo2 remained consistently lower in diabetic than in nondiabetic patients. We conclude that diabetes causes a reduction in limb TcPo2 beyond that which can be accounted for by large-vessel arterial occlusive disease alone.

Age Factors↗
PubMed1989

Influence of coronary artery disease on morbidity and mortality after abdominal aortic aneurysmectomy: a population-based study, 1971-1987.

The prognostic importance of coronary artery disease at the time of elective abdominal aortic aneurysmectomy was evaluated among 131 residents of Olmsted County, Minnesota who underwent elective aneurysmectomy from 1971 to 1987 and were followed up to 1988 for death and cardiac events (cardiac death, myocardial infarction, coronary bypass surgery and angioplasty). Before aneurysmectomy, 75 patients (Group 1) had no clinically recognized coronary disease, 47 patients (Group 2) had suspected or overt uncorrected coronary artery disease (history of prior myocardial infarction, angina or a positive stress test) and 9 patients (Group 3) had undergone coronary artery bypass grafting or coronary angioplasty. The 30 day operative mortality rate was 3% (2 of 75) in Group 1 and 9% (4 of 47) in Group 2 (p = 0.15). According to Kaplan-Meier analysis, estimated survival 8 years after aneurysmectomy was 59% (expected rate 68%, p = 0.29) in Group 1 versus 34% (expected rate 61%, p = 0.01) in Group 2. The cumulative incidence rate of cardiac events at 8 years was 15% and 61%, respectively, for patients without and with suspected/overt coronary artery disease (p less than 0.01). Using multivariable proportional hazards analysis, uncorrected coronary artery disease was associated with a nearly twofold increased risk of death (hazard ratio 1.79, 95% confidence interval 1.06 to 3.00) and a fourfold increased risk of cardiac events (hazard ratio 3.71, 95% confidence interval 1.79 to 7.69). These population-based data support an aggressive life-long approach to the management of coronary artery disease in patients undergoing abdominal aortic aneurysmectomy.

Aged↗
PubMed1989

Variability and reproducibility of transcutaneous oxygen tension measurements in the assessment of peripheral vascular disease.

Transcutaneous oxygen tension (TcPO2) was measured according to a standard protocol in 43 limbs from 23 subjects, by use of oxygen-sensing electrodes attached to the chest (at a single site) or dorsum of the foot (at proximal and distal sites, located 1-2 cm apart). With the subjects supine, distal foot TcPO2 differed from proximal by an average of +/- 7.4 mmHg, and in 80% of all limbs the differences were between -6 mmHg and +15 mmHg. The two TcPO2's were subsequently combined to yield a single "average" value for each foot. TcPO2 measurements were repeated twenty-four to forty-eight hours later; in the supine position the change in "average" foot TcPO2 from the first to second measurement was +/- 6.9 mmHg, and in 80% of limbs the changes were between -11 mmHg and +9 mmHg. Similar reproducibility data were also obtained for ankle/brachial blood pressure indices (ABIs), chest TcPO2, and foot TcPO2 during three minutes of leg elevation at 30 degrees. The authors conclude that: (1) TcPO2 measurements from adjacent areas on the dorsum of the foot usually differ by 20-25% or less and (2) the short-term reproducibility of TcPO2 between studies is comparable to that for ABIs.

Arterial Occlusive Diseases↗
PubMed1988

Effect of intermittent venous occlusion on transcutaneous oxygen tension in lower limbs with severe arterial occlusive disease.

We evaluated the ability of intermittent venous occlusion to improve cutaneous circulation in patients with severe peripheral arterial occlusive disease. Fourteen patients with ischemic lower extremities had a pneumatic cuff placed around the thigh of an ischemic limb; intermittent inflation of this cuff produced a significant increase in the transcutaneous oxygen tension of the foot, suggesting that cutaneous blood flow had been improved.

Arterial Occlusive Diseases↗
PubMed1988

Effect of arterial revascularization on transcutaneous oxygen tension of the ischemic extremity.

In 20 patients (24 limbs) with peripheral occlusive arterial disease involving the lower extremities, foot and chest transcutaneous oxygen tension (tcPO2) and ankle and arm systolic blood pressures were measured, with the patient's legs horizontal and with them in an elevated position, before and after revascularization procedures. Eighteen of the procedures were unilateral and were performed to alleviate severe ischemia; the three bilateral procedures were done to relieve intermittent claudication. Regional perfusion index (RPI) was calculated for each foot (RPI = tcPO2 foot/tcPO2 chest) with the legs horizontal and with the legs elevated for 3 minutes (RPI3). The ankle/brachial index was calculated from ankle and arm systolic blood pressures. Limbs with severe ischemia had considerably decreased RPI and RPI3 before revascularization, whereas limbs affected by claudication had only a modest decrease in RPI but a pronounced decrease in RPI3. The tcPO2, RPI, and RPI3 increased substantially after revascularization.

Arm↗
PubMed1987

Percutaneous transluminal angioplasty in the lower extremities: a 5-year experience.

From January 1979 to March 1984, percutaneous transluminal angioplasty (PTA) was used to treat 148 limbs of 135 Mayo Clinic patients with occlusive arterial disease of the lower extremities. The procedure was technically successful in more than 95% of the attempts. The outcome was clinical improvement in 89 limbs and no improvement in 40 limbs; in 19 limbs, PTA was technically successful but the patient was dismissed from the hospital and lost to follow-up before the extent of improvement could be determined. Mean ankle/brachial pressure indices increased after PTA in those with clinical improvement but not in those without improvement. Clinical improvement was less likely to follow PTA in patients with advanced age, diabetes, severe initial symptoms, low ankle/brachial indices, or distal occlusive disease. In patients with improvement after PTA, the mean follow-up period was 33 months; during that time, failure (defined as recurrence of the original symptoms or the need for repeat PTA or operation) occurred at a rate of 6.4% per year. Serious complications occurred after three procedures (2.0%). We conclude that PTA is technically feasible and generally safe for many patients with occlusive arterial disease of the lower limbs.

Aged↗
PubMed1987

The influence of sympathetic nerves on transcutaneous oxygen tension in normal and ischemic lower extremities.

The authors evaluated the relationship between sympathetic nerve activity and transcutaneous oxygen tension (TcpO2) in normal and ischemic lower extremities. Dorsal foot TcpO2 was measured by using oxygen-sensing electrodes with surface temperatures of 42 degrees C and 45 degrees C; in theory, changes in sympathetic activity should affect vasomotor tone and TcpO2 in skin beneath an electrode at 42 degrees C (submaximal vasodilation), but not at 45 degrees C (maximal vasodilation). The vasodilation index (TcpO2 at 42 degrees C/TcpO2 at 45 degrees C) was created as an index of vasomotor tone (vasodilation index increases as tone decreases). In normal limbs (n = 24) averages for TcpO2 at 42 degrees C, TcpO2 at 45 degrees C, and vasodilation index were 30.3 mmHg, 62.1 mmHg, and 0.47, respectively. In subjects (n = 5) with quadriplegia and reduced sympathetic tone secondary to cervical cord trauma, TcpO2 at 42 degrees C and vasodilation index were increased (45.0 mmHg and 0.61); TcpO2 at 45 degrees C did not change. When normal subjects (n = 7) were chilled for twenty minutes with a cooling blanket at 5 degrees C (to increase sympathetic tone) average vasodilation index dropped from 0.50 to 0.29. Among ischemic limbs (n = 34) vasodilation index was highly variable (range: 0-0.77); in general, vasodilation index fell as the ischemia worsened. In a subset of patients with ischemic limbs, the vasodilation index increased after the limb was wrapped in a warm dressing (average vasodilation index = 0.25 without dressing, 0.37 with dressing). The authors conclude: TcpO2 can be used to assess the degree of vasomotor tone (and sympathetic activity) in skin; tone generally increases as ischemia worsens; and local warmth can improve cutaneous circulation in ischemic limbs.

Cold Temperature↗
PubMed1986

Heparin and the in-hospital management of deep venous thrombosis: cost considerations.

Numerous protocols for the treatment of deep venous thrombosis (DVT) with heparin have been recommended. In the past, physicians rarely considered costs in their decision to use a particular protocol; however, the recent introduction of the diagnosis-related groups (DRGs) and other cost-reduction measures has imposed financial limitations on the practice of medicine and surgery. To determine how the cost of treatment for DVT at the Mayo Clinic might be affected by the use of alternative heparin protocols, we conducted a two-stage study. In the first part, charts of 40 patients with uncomplicated DVT were analyzed retrospectively to determine an "average" Mayo Clinic heparin protocol for DVT. In the second part, this "average" protocol was compared with four other currently advocated protocols, and the cost of using each protocol at the Mayo Clinic was estimated. These protocols differed from the Mayo Clinic protocol with respect to method and route of heparin administration, frequency of monitoring anticoagulation, and duration of heparin treatment. This analysis revealed that the average charges resulting from treatment of DVT at the Mayo Clinic exceeded the corresponding DRG payment and that the cost of treatment varied substantially with the protocol used (a difference of more than $2,000 between two of the protocols analyzed). A review of the literature provided little evidence to suggest that the alternative protocols were not equally effective. Therefore, we concluded that measures such as shortening the duration of heparin therapy, administration of heparin by the subcutaneous route, and minimal monitoring of anticoagulation (in patients with a low risk of bleeding) can substantially reduce the cost of treating DVT and may be no less effective than other protocols for heparinization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Use of captopril as early therapy for renal scleroderma: a prospective study.

We conducted a prospective study of captopril therapy in patients with scleroderma and combined hypertension and renal insufficiency. In all seven patients studied during a 1-year period, control of blood pressure was achieved, and in six of the seven, renal function stabilized or improved. The total daily dosage of captopril ranged from 32 to 100 mg, divided into doses taken every 6 to 8 hours. Although one patient had a suspected captopril-induced rash for a short time, none of the other patients had any adverse side effects. Renal biopsies were performed in six patients; in three of them, specimens were obtained both at the beginning and at the end of the study. The initial biopsy specimens showed changes that were similar to those described in other reports. Findings on repeat biopsies were unchanged except for evidence of chronicity. In the six patients with controlled blood pressure and improved or stabilized renal function, the improvement was maintained for 1 1/2 to nearly 3 years on this drug therapy. Using specific measurements of skin compliance and vascular blood flow in the upper extremities, we could detect no evidence, however, of concomitant improvement in these other features of the disease. Although the blood pressure was controlled with captopril, one patient had progressive skin induration, one had progressive pulmonary insufficiency, and another had progressive renal failure.

Adult↗
PubMed1985

Reproducibility of noninvasive tests of peripheral occlusive arterial disease.

We studied the reproducibility of four tests of peripheral occlusive arterial disease in 54 subjects, 32 of whom had this disease. We found that the reproducibility of systolic blood pressures obtained at rest from the thighs, calves, and ankles approximated that of arm systolic and diastolic blood pressures, as did the ankle-to-arm systolic blood pressure ratios. The average of the tenth and ninetieth percentile ranges of the resting systolic blood pressure ankle-to-arm ratios was +/- 0.10. Systolic blood pressures from the fingers were somewhat less reproducible, and those from the toes were even more variable. Systolic blood pressure ankle-to-arm ratios measured after the patient had exercised were less reproducible than resting ratios. The average of the tenth and ninetieth percentile ranges of the 1-, 3-, 5-, and 10-minute ratios after exercise was -0.13 to +0.16. Skin temperatures from the fingers and toes were approximately as reproducible as systolic blood pressures from the arms and legs and as the resting ankle-to-arm blood pressure ratios. Pulse-volume recordings from the thighs, calves, ankles, feet, toes, and fingers were very poorly reproducible. We conclude that information on the reproducibility of these measurements is essential in the evaluation of noninvasive arterial tests that are used to determine the course of peripheral occlusive arterial disease.

Arm↗
PubMed1984

Trial of platelet-inhibiting drug in scleroderma. Double-blind study with dipyridamole and aspirin.

In a randomized, double-blind, controlled study, 28 patients with early scleroderma received dipyridamole (225 mg/day) and aspirin (975 mg/day) or placebo for 1-2 years. No significant clinical or objective laboratory improvement was noted in either group. Platelet survival time, plasma renin activity, and coagulation tests were not predictive of disease course. Biomechanical and vascular tests of the hands correlated with clinical extent of skin induration and presence of finger ulcers, respectively.

Aspirin↗