Discordance between cardiopulmonary physiology and physical therapy. Toward a rational basis for practice.
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Biological Transport↗
Biomedical subjects
E Dean
Publications and source records attributed to E Dean.
Discordance of airflow limitation and ventilatory inhomogeneity in asthma and cystic fibrosis.
Although it is known that both airflow rates and gas distribution are impaired in asthma and cystic fibrosis (CF), the concordance of the change in these defects between two points in time has not been studied. On two separate occasions, the FEV1, FVC and slope of Phase III (SBN2/L%) of the single breath nitrogen test were determined, as well as the concordance between the change in these indices in 14 healthy subjects, 14 subjects with asthma, and seven subjects with CF. The coefficient of variation within a test session averaged less than 5% for the FEV1 and less than 10% for the SBN2/L% within each group. The change in FEV1 correlated with the change in FVC in all three groups, but did not correlate with the change in SBN2/L% in any group. In seven of the 14 cases of asthma and six of the seven cases of CF (outliers), the differences in the indices (expressed as the change in percent predicted) were greater than the differences observed in the control group. In three of the asthmatic and four of the CF outliers, the changes were as predicted, that is, both tests returned toward normal, or both became more abnormal. In two of the asthmatic and CF outliers both the FEV1 and SBN2/L% increased, while both decreased in the other two asthmatic outliers. Although some of the same factors will affect both indices, a worsening of ventilation inhomogeneity, which will affect the SBN2/L%, could occur with an improvement in ventilatory flow rate. Alternatively, airflow limitation could worsen but be accompanied by an improvement in ventilation homogeneity.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Clinical decision making in the management of the late sequelae of poliomyelitis.
Years after the initial onset of poliomyelitis, patients often report new problems, including fatigue, weakness, pain, breathing difficulty, decreased endurance, problems with swallowing, choking, increased sensitivity to cold, and psychological problems. The premise of this article is that underlying pathophysiology of these problems can be assessed on the basis of a detailed history, a multisystem physical examination, and supplemental information provided by investigative tests. The indications for treatment of the late sequelae of poliomyelitis based on the underlying pathophysiology and the rationale for treatment prescription are explored. Possible outcomes of the assessment include no intervention; prescription of a balance between activity and rest, a reduction in activity, or an increase in activity; interventions to improve postural alignment, prescription of orthoses, and weight control; prescription of walking aids and mobility devices; respiratory care; lifestyle modification; or some combination of these outcomes. If treatment can be directed at the underlying causes of the late sequelae, the possibility of reducing further deterioration and of optimizing function in these patients will likely be enhanced.
Diagnosis, Differential↗
Pulmonary function in individuals with a history of poliomyelitis.
We examined the relationship between the lung function of 74 individuals with a history of poliomyelitis and reports of shortness of breath during activities of daily living, and the presence of post-polio sequelae risk factors. First, we studied the spirometry of 60 individuals (group 1) and second, we studied the relationship between the spirometry of an additional 14 individuals (group 2) and their respiratory muscle strength (Pimax and Pemax). In both groups, we examined the relationship between factors associated with post-polio sequelae including ventilation at polio-onset, having contracted polio after the age of 10, and having had polio for over 35 years; and lung function. In group 1, the FEV1 and FVC were lower for individuals with shortness of breath than individuals without (p less than 0.01). With respect to risk factors, FEV1 and FVC were lower in individuals who were ventilated at polio-onset, in individuals who contracted polio over 10 years of age, and in individuals who had had polio for less, rather than more than 35 years (p less than 0.05). The results for group 2 were comparable to group 1. In addition, the observed Pimax and Pemax were significantly lower than predicted values (p less than 0.05). Although FEV1 and FVC were positively correlated with both Pimax and Pemax (p less than 0.05), Pemax was disproportionately impaired compared to Pimax (40 +/- 12.1 and 82 +/- 38.8 percent predicted respectively). We conclude that individuals with a history of poliomyelitis can have compromised lung function irrespective of shortness of breath, that risk factors such as ventilation at polio-onset and polio-onset after 10 years of age can help predict those at risk of respiratory compromise, and that the measurement of respiratory muscle strength and of Pemax in particular, can augment the assessment of lung function of these individuals. Such assessment may avert respiratory complications in the post poliomyelitis population including those secondary to health care interventions.
Adult↗
Effect of modified aerobic training on movement energetics in polio survivors.
Given that individuals with disabilities may be unable to achieve maximal oxygen uptake in an exercise test and that maximal exercise testing may cause increased fatigue, pain, and muscle weakness, we examined the role of submaximal exercise testing and training based on objective as well as subjective parameters in polio survivors. Experimental (N = 7) and control subjects (N = 13) were tested before and after a 6-week period. The experimental subjects participated in a 6-week exercise training program for 30 to 40 minutes, three times a week. The program consisted of treadmill walking at 55% to 70% of age-predicted maximum heart rates; however, exercise intensity was modified to minimize discomfort/pain and fatigue. Neither objective nor subjective exercise responses were significantly different in the control group over the 6 weeks. No change was observed in cardiorespiratory conditioning in the experimental group. However, movement economy, which is related to the energy cost of walking, was significantly improved; and walking duration was significantly increased at the end of training. Modified aerobic training may have a role in enhancing endurance and reducing fatigue during activities of daily living in polio survivors.
Adult↗
Semitendinosus repair augmentation of acute anterior cruciate ligament rupture.
The semitendinosus tendon has been used since 1980 by the senior author (J.P.M) to augment anterior cruciate ligament repair surgery in cases of acute rupture. There are two major criticisms of this technique: first, the semitendinosus tendon lacks adequate tensile strength functionally to replace the normal anterior cruciate ligament; and second, the semitendinosus is an important hamstring muscle, the loss of which has the potential to weaken the dynamic control of the knee. Objective measurement of success or failure of this procedure is provided by KT1000 arthrometer laxity testing for static recovery of stability, and by Cybex isokinetic dynamometer testing of peak torque and fatigue index to evaluate muscular rehabilitation. Thirty-seven patients were examined using these techniques in a standardized protocol at least two years after surgery. Results show excellent return of static stability and near-normal recovery of strength and endurance of quadriceps and hamstring muscles.
Adult↗
Downhill walking induces rapid shallow breathing.
To examine the effect of downhill walking a form of negative work on ventilation, we studied the exercise responses of 13 healthy subjects during uphill and downhill walking on a treadmill. Each test lasted 16 min and the peak work rate was 5.6 kph with either a positive or negative 14% grade. Throughout each test we recorded VO2, VE, f, VT, HR, systolic BP and Borg's rating of perceived exertion. At the target work rates of 5.6 kph +/- 14% grade, VO2 and VE were three times greater in uphill compared with downhill walking. However, in downhill walking, f was greater compared with uphill walking wherein VT approximated baseline values, reflecting rapid shallow breathing, and VT appeared to increase after reaching some critically-low level. These trends persisted when VO2 was held constant (p less than 0.01). HR and systolic BP increased and decreased with the positive and negative grade respectively. At a constant VO2 however, HR was significantly higher during downhill compared with horizontal walking (p less than 0.01) whereas systolic BP was not significantly different (p greater than 0.05). We conclude that there is a significant difference in the ventilatory responses between the two types of work performed on a treadmill. Specifically, downhill walking is associated with rapid shallow breathing which may be countered by a protective feedback mechanism at critically-low levels of VT.
Adult↗
Genetic and molecular analysis of a Caenorhabditis elegans beta-tubulin that conveys benzimidazole sensitivity.
Benzimidazole anti-microtubule drugs, such as benomyl, induce paralysis and slow the growth of the nematode Caenorhabditis elegans. We have identified 28 mutations in C. elegans that confer resistance to benzimidazoles. All resistant mutations map to a single locus, ben-1. Virtually all these mutations are genetically dominant. Molecular cloning and DNA sequence analysis established that ben-1 encodes a beta-tubulin. Some resistant mutants are completely deleted for the ben-1 gene. Since the deletion strains appear to be fully resistant to the drugs, the ben-1 product appears to be the only benzimidazole-sensitive beta-tubulin in C. elegans. Furthermore, since animals lacking ben-1 are viable and coordinated, the ben-1 beta-tubulin appears to be nonessential for growth and movement. The ben-1 function is likely to be redundant in the nematode genome.
Alleles↗
Pathophysiology and cardiorespiratory consequences of interstitial lung disease--review and clinical implications: a special communication.
The purpose of this special communication is to review the pathophysiology of interstitial lung disease (ILD) and its cardiorespiratory consequences at rest and during exercise. Patients with ILD tend to have a resting and disproportionate exercise tachycardia; resting or exercise-induced arterial desaturation; a rapid shallow breathing pattern; and in more severe cases an increase in pulmonary arterial pressure with an associated increase in right ventricular work. Although the acute exercise responses of patients with ILD have been documented, studies on their responses to exercise training are lacking. We, therefore, discuss some of the physiologic consequences of ILD and the clinical measures available to assess these patients at rest and during exercise. We present the implications of these changes for functional ability and propose that modified endurance training is important to the patient with ILD. Potential directions for clinical research in exercise training of patients with ILD are presented.
Exercise↗
Integrating physiological principles into the comprehensive management of cardiopulmonary dysfunction.
Impairment of oxygen transport can be conceptualized as a motion disorder based on the framework previously reported by Hislop and Zadai. Extensive literature exists that demonstrates the beneficial effects of body positioning and mobilization on impaired oxygen transport. This article integrates this existing information and attempts to extend the framework of Hislop and Zadai in cardiopulmonary physical therapy. To provide a basis for discussion, we describe the multisystemic consequences of immobility from bed rest. We also discuss the role of body positioning and mobilization as therapeutic interventions that can be used to directly enhance all components of oxygen transport in patients with cardiopulmonary dysfunction. This approach may improve the efficacy of treatment in these patients and thus may address some of the limitations of current methods of practice. Further research is needed, however, to clarify and extend the application of this approach.
Adult↗
A rejoinder to "Exercise Programs for Patients with Post-Polio Syndrome: a case report"--a short communication.
This communication is in response to the article by Michael T Gross and Charles P Schuch entitled "Exercise Programs for Patients with Post-Polio Syndrome: A Case Report" published in the January 1989 issue of Physical Therapy. The investigators examined the effects of a rigorous isokinetic training program on peak torque of the knee flexor and extensor muscles of a post-polio patient. The literature on post-polio syndrome, however, does not support the use of either conventional muscle strengthening regimens or rigorous isokinetic exercise programs in the management of post-polio syndrome. In addition, based on the observation that there was no appreciable increase in muscle strength in either the affected or the apparently unaffected leg, the investigators concluded that their rigorous exercise program was not deleterious. The lack of a normal training response, however, is consistent with bilateral muscle fatigue secondary to overuse rather than muscle weakness secondary to disuse. This result is consistent with the need for a balance between rest and low-intensity exercise, which will help to maintain or enhance function while slowing rather than hastening further deterioration. We hope that this rejoinder clarifies some of the misconceptions that may arise from the Gross and Schuch article and that physical therapists consider very carefully the rationale for any type of exercise program for post-polio patients.
Exercise Therapy↗
Improving the validity of clinical exercise testing: the relationship between practice and performance.
Many studies involving exercise testing fail to address the issue of practice. Those that do vary considerably with respect to the parameters of practice used. We evaluated the effect of two standardized practices on a horizontal submaximal exercise test performed on a treadmill. Healthy men (n = 20) with no previous treadmill exposure were alternately assigned to the experimental (practice) or control (no practice) group. Heart rate (HR), systolic blood pressure (SBP), rate pressure product (RPP), step cadence (CAD) and perceived exertion (PE) were recorded at the end of each work load of the practices and/or tests. We observed no significant differences in these variables over the common work loads for the first practice session in the experimental group and the exercise test in the control group (p greater than 0.05). The two groups were homogeneous with respect to fitness and magnitude of arousal on initial exposure to the treadmill. During the submaximal test, HR, SBP, RPP, CAD, and PE were systematically lower for the experimental group than for the control group. The SBP and RPP were significantly lower in the experimental group (p less than 0.01). The CAD tended toward statistical significance (p less than 0.07), whereas HR and PE were not significantly different for the two groups (p greater than 0.05). When the four common work loads were compared over the two practices and the exercise test for the experimental group, SBP and CAD were significantly higher for practice 1 than for practice 2 and the test (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Physiology and therapeutic implications of negative work. A review.
Energy efficiency is an important attribute of negative work (W neg). Eccentric muscle contractions characteristic of W neg can generate greater force at reduced oxygen cost and perceived exertion compared with concentric muscle contractions in positive work (W pos). Thus, activities incorporating W neg could have important implications in improving the functional capacity of an individual with limited physiologic reserves or ability to use these reserves. Other characteristics of W neg such as muscle trauma or soreness and increased total heat production and cutaneous blood flow, however, may be counter-therapeutic and even hazardous. The purpose of this review is to describe the physiology and therapeutic implications of W neg. Because the body of knowledge with respect to the therapeutic effects of W neg is relatively scant compared with W pos, clinical trials are needed to establish the indications, contraindications, possible limitations, guidelines for prescription, and therapeutic efficacy of W neg.
Energy Metabolism↗
Bilateral chondrodermatitis nodularis antihelicis. An unusual complication of cardiac pacemaker insertion.
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Aged↗
Apparent finger systolic pressures during cooling in patients with Raynaud's syndrome.
Despite considerable research, the mechanisms responsible for the vasospasm associated with Raynaud's syndrome are not well understood and there is no reliable diagnostic test. In the present studies, measurements of systolic pressure in locally cooled fingers were used to address these issues. We found that local cooling produced a marked decrease or loss of the apparent finger systolic pressure in patients with Raynaud's syndrome in whom a standardized vasoconstriction had been induced by body cooling. Abnormal responses were encountered in 109 of 125 patients with secondary Raynaud's syndrome, in 21 of 37 patients with primary Raynaud's disease or the syndrome of uncertain cause, and in two of 63 subjects without symptoms of Raynaud's. These data suggest a high accuracy of the test in patients with secondary Raynaud's syndrome and lower accuracy in those with disease of primary or uncertain cause. We studied responses of systolic pressures to alterations in body and local temperatures in fingers with and without low pressures secondary to proximal arterial obstruction. Our data show that although local cooling has a small independent effect that increases vascular tone: (1) sympathetic vasoconstriction induced by body cooling is necessary to produce vasospasm and often produces it without local cooling, (2) high local temperature (30 degrees C) protects from vasospasm, and (3) low finger blood pressure predisposes to it. Delayed opening of the vessels observed after sudden deflation of blood pressure cuffs suggests that abnormal responses of finger systolic pressure to cold represent combined effects of high vascular tone, delayed opening, and local blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Modified aerobic walking program: effect on patients with postpolio syndrome symptoms.
Modified aerobic exercise may have a role in the management of patients with symptoms of postpolio syndrome by improving biomechanical efficiency, alleviating secondary cardiorespiratory and muscular deconditioning, and avoiding some risks associated with traditional strengthening exercises. The effects of a walking program on the functional capacity of patients with symptoms of postpolio syndrome were studied. Three patients participated in full oxygen consumption studies during submaximal treadmill exercise tests before and after an eight-week period. Two patients participated in an eight-week program designed to prolong walking duration while maintaining perceived exertion and discomfort/pain at minimal levels. A third patient was tested before and after eight weeks but did not receive training. The untrained patient showed some reduction in the retest compared with the initial test at all workloads with respect to oxygen consumption, heart rate, and systolic blood pressure, but ratings of perceived exertion and discomfort/pain were comparable for the two tests. Reductions in metabolic responses during the retest could be explained by the effect of habituation to the testing situation. In contrast, the trained patients showed relatively marked reductions in both metabolic and subjective responses after training. These results suggest that patients with symptoms of postpolio syndrome can increase their functional work capacity after a modified aerobic walking program. This improvement reflects improved biomechanical efficiency and possible training effects at the cardiorespiratory and muscular levels. Further research is needed to elucidate the role and interactions of these mechanisms in improving the functional work capacity of patients with chronic neuromuscular dysfunction.
Adult↗
Frequency of citation and reputational assessment of contributors in physical therapy.
This article describes a study designed to determine whether a correlation exists between those contributors whom practicing physical therapists consider to be eminent in the profession and those contributors with high citation frequencies in the current physical therapy literature. The study consisted of a citation analysis of a two-year period, 1981 and 1982, of the journals Physical Therapy and Physiotherapy Canada to identify the most frequently cited authors. Forty physical therapists practicing in two large general hospitals in Vancouver, Canada, volunteered to rate a random selection of contributors to the profession using a scale of 0 to 10 according to their apparent influence on the profession. Our study revealed that the scores of the therapists were correlated with the frequencies based on the citation analysis (p less than .05). We further observed that the citation frequency of authors in the Canadian journal was correlated with the citation frequency of authors in the American journal (p less than .05). We conclude that, with the increased emphasis on research in physical therapy, a stronger relationship will develop between subjective and objective measures of the professional impact of contributors on the profession.
Canada↗
Mutations affecting microtubule structure in Caenorhabditis elegans.
Three types of microtubules are seen in the neuronal processes of the nematode Caenorhabditis elegans. Single cytoplasmic microtubules of most neurones have 11 protofilaments whereas those of six touch receptor cells have 15 protofilaments. The axonemes of sensory cilia have nine outer doublets with a variable number (up to seven) of singlet microtubules. Mutations in 11 genes affect the appearance of these microtubules.
Animals↗