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PubMed1988

Interposed abdominal compressions and carotid blood flow during cardiopulmonary resuscitation. Support for a thoracoabdominal unit.

To determine if the timing of interposed abdominal compressions (IAC) affects the augmented blood flow during this form of cardiopulmonary resuscitation (CPR), we performed early-onset or late-onset abdominal compressions at three vascular volumes in nine dogs. Early-onset IAC began immediately following chest compression; we predicted that this would act primarily by emptying the aorta and sustaining the elevated intrathoracic pressure. Late-onset IAC began one-fourth to one-third of the time into diastole; this would have primarily increased venous return. We measured carotid blood flow (electromagnetic flow probe) and right atrial (Pra), thoracic aortic (Pta), abdominal aortic (Paa), and intra-abdominal pressures. The IAC-CPR increased carotid blood flow compared with conventional CPR (22.8 +/- 13.1 percent vs 8.7 +/- 5.8 percent of control; p less than 0.003), but there was no difference between the early and late modes of IAC (22.7 +/- 11.6 percent vs 22.9 +/- 14.7 percent of control). The increase in carotid blood flow was present with the first abdominal compression and was constant over the 40 to 60 seconds of CPR. Peak Pra, Pta, and Paa were similar during abdominal compression (91.8 +/- 16.9 mm Hg, 96.1 +/- 16.0 mm Hg, and 102.4 +/- 15.2 mm Hg, respectively; p less than 0.001). The Pta-Pra diastolic gradient was 18.0 +/- 8.2 mm Hg for early-onset and 20.6 +/- 7.5 mm Hg for late-onset compression (not significant). We conclude that increased carotid blood flow in IAC-CPR in the dog is principally due to the increased pressure in a common thoracoabdominal unit.

Abdomen↗

PubMed2002

V-shaped deceleration differs in the pattern of carotid blood flow from variable deceleration provoked by cord compression.

OBJECTIVE: To investigate whether V-shaped decelerations in fetal heart rate tracing are a physiologic response to fetal movements or secondary to cord compression. STUDY DESIGN: Six pregnant sheep and their fetuses (115-125 days of gestation) were surgically instrumented and studied. Fetal electrocardiogram, carotid blood flow, arterial blood pressure and fetal movement were continuously monitored for 24 hours. Following the undisturbed 24 hour recording, these parameters were monitored during umbilical cord compression (n = 6). Differences in these parameters between V-shaped decelerations and decelerations provoked by cord compressions were examined. RESULTS: Elevation of blood pressure and decreased carotid blood flow were observed coincidentally with the initiation of V-shaped decelerations. In cord compression, elevation of both blood pressure and carotid blood flow were followed by a decreased heart rate. V-shaped decelerations exhibited a different alteration of carotid blood flow compared to decelerations caused by umbilical cord compression. CONCLUSION: V-shaped deceleration is a physiologic response secondary mainly to fetal movements and is not caused by cord compression.

Animals↗

PubMed2005

Local compressibilities of proteins: comparison of optical experiments and simulations for horse heart cytochrome-c.

Spectroscopy with probe molecules yields local information on the environment of the probe. In this article we compare local compressibilities of cytochrome-c as obtained from molecular dynamics simulations with experimental results as obtained from spectroscopic measurements. The simulations show that the protein-core around the heme is much less compressible in a glycerol/water solvent than in pure water. The pocket is also much less compressible than the protein as a whole, although the compressibility of the water inside the rather incompressible protein-core is almost liquidlike. We show that the local compressibility values capture the collective correlations of local volume fluctuations with volume fluctuations in the surrounding protein-solvent system. The decoupling of the volume fluctuations of the core from the solvent shell explains the reduction of the heme-core-compressibility in glycerol/water solvent. This decoupling could be traced back to the suppression of the exchange between pocket-water and hydration-shell-water upon addition of glycerol as co-solvent.

Absorption↗

PubMed2005

Temporal expression patterns and corresponding protein inductions of early responsive genes in rabbit bone marrow-derived mesenchymal stem cells under cyclic compressive loading.

Our recent study suggested that cyclic compressive loading may promote chondrogenesis of rabbit bone-marrow mesenchymal stem cells (BM-MSCs) in agarose cultures through the transforming growth factor (TGF)-beta signaling pathway. It has been shown that the activating protein 1 (AP-1) (Jun-Fos) complex mediated autoinduction of TGF-beta1 and its binding activity was essential for promoting chondrogenesis of mesenchymal cells, whereas Sox9 was identified as an essential transcription factor for chondrogenesis of embryonic mesenchymal cells. The objective of this study was to examine temporal expression patterns of early responsive genes (Sox9, c-Fos, c-Jun, and TGF-beta type I and II receptors) and induction of their corresponding proteins in agarose culture of rabbit BM-MSCs subjected to cyclic compressive loading. The rabbit BM-MSCs were obtained from the tibias and femurs of New Zealand White rabbits. Cell-agarose constructs were made by suspending BM-MSCs in 2% agarose gel (10(7) cells/ml) for cyclic, unconfined compression tests performed in a custom-made bioreactor. In the loading experiment, specimens were subjected to sinusoidal loading with a magnitude of 15% strain at a frequency of 1 hertz for 4 hours per day. Experiments were conducted for 2 consecutive days. This study showed that cyclic compressive loading promoted gene expressions of Sox9, c-Jun, and both TGF-beta receptors and productions of their corresponding proteins, whereas those gene expressions exhibited different temporal expression patterns among genes and between 2 days of testing. The gene expression of c-Fos was detected only in the samples subjected to1-hour dynamic compressive loading. These findings suggest that the TGF-beta signal transduction and activities of AP-1 and Sox9 are involved in the early stage of BM-MSC chondrogenesis promoted by dynamic compressive loading.

Animals↗

PubMed2004

Effects of cyclic compressive loading on chondrogenesis of rabbit bone-marrow derived mesenchymal stem cells.

The objective of this study was to examine the effects of cyclic compressive loading on chondrogenic differentiation of rabbit bone-marrow mesenchymal stem cells (BM-MSCs) in agarose cultures. Rabbit BM-MSCs were obtained from the tibias and femurs of New Zealand white rabbits. After the chondrogenic potential of BM-MSCs was verified by pellet cultures, cell-agarose constructs were made by suspending BM-MSCs in 2% agarose (10(7) cells/ml) for a cyclic, unconfined compression test performed in a custom-made bioreactor. Specimens were divided into four groups: control; transforming growth factor (TGF-beta) (with TGF-beta1 treatment); loading (with stimulation of cyclic, unconfined compressive loading); and TGF-beta loading (with TGF-beta1 treatment and loading stimulation) groups. In the loading experiment, specimens were subjected to sinusoidal loading with a 10% strain magnitude at a frequency of 1 Hz for 4 hours a day. Experiments were conducted for 3, 7, and 14 consecutive days. While the experimental groups (TGF-beta, loading, and TGF-beta loading) exhibited significantly higher levels of expressions of chondrogenic markers (collagen II and aggrecan) at three time periods, there were no differences among the experimental groups after an extra 5-day culture. This suggests that compressive loading alone induces chondrogenic differentiation of rabbit BM-MSCs as effectively as TGF-beta or TGF-beta plus loading treatment. Moreover, both the compressive loading and the TGF-beta1 treatment were found to promote the TGF-beta1 gene expression of rabbit BM-MSCs. These findings suggest that cyclic compressive loading can promote the chondrogenesis of rabbit BM-MSCs by inducing the synthesis of TGF-beta1, which can stimulate the BM-MSCs to differentiate into chondrocytes.

Aggrecans↗

PubMed1996

Intermittent pneumatic compression prophylaxis for proximal deep venous thrombosis after total hip replacement.

The efficacy of intermittent pneumatic compression in the prevention of proximal deep venous thrombosis was determined in a consecutive series of patients who had primary or revision total hip replacement. Two hundred and eighty-nine patients (242 primary and eighty revision hip replacements) who were at least forty years old were managed intraoperatively and postoperatively with intermittent pneumatic compression with use of thigh-high sequential compression sleeves and thigh-high elastic compression stockings as the only form of prophylaxis. Venous ultrasonography of the ipsilateral lower extremity was performed, at an average of five days postoperatively, to determine the presence of a thrombus in the femoral and popliteal veins. The prevalence of proximal deep venous thrombosis was 6 per cent (twenty of 322 procedures), and no patient had a clinically detected pulmonary embolism. The prevalence of a proximal thrombus was 4 per cent (ten of 233 procedures) when a regional anesthetic had been used and 11 per cent (ten of eighty-nine procedures) when a general anesthetic had been used; this difference was significant (p = 0.02). The prevalence of a proximal thrombus was 3 per cent (eight of 245 procedures) for patients who were less than seventy-five years old and 16 per cent (twelve of seventy-seven procedures) for patients who were seventy-five years old or more (p < 0.0001). No patient had a major bleeding complication. Twenty-nine other patients who had an additional risk factor for thrombosis, such as a history of deep venous thrombosis, were managed with intermittent pneumatic compression and low-dose warfarin. The prevalence of proximal deep venous thrombosis in this group of patients was 19 per cent (six of thirty-one procedures). Intraoperative and postoperative intermittent pneumatic compression, combined with the use of a regional anesthetic, was found to be highly effective in the prevention of proximal deep venous thrombosis after total hip replacement. Despite the limitations inherent in comparisons among series, it is noteworthy that the prevalence of proximal thrombosis in our series was similar to the reported prevalences in several large series of patients who had a total hip replacement and were managed with either low-dose warfarin or low-molecular-weight heparin. However, there was no risk of major postoperative bleeding in the current study.

Adult↗

PubMed2003

Effect of intermittent pneumatic soft-tissue compression on fracture-healing in an animal model.

BACKGROUND: The fracture-healing process is closely related to blood supply. Intermittent pneumatic compression of the surrounding soft tissue may alter blood flow and, therefore, modify the healing process. The object of the present study was to evaluate the effect of intermittent pneumatic compression on fracture-healing in an animal model. METHODS: Unilateral, transverse, mid-tibial osteotomies with a 3-mm gap were performed in thirty rabbits. The osteotomy site was stabilized with a double-bar external fixator. The femoral vein was ligated to induce venous stasis. Beginning on the fourth postoperative day, fifteen rabbits were treated with intermittent pneumatic compression with use of four rubber balloons, two around the distal part of the calf and two around the midpart of the calf, for one hour daily for four weeks (the study group) and fifteen rabbits were not treated with intermittent pneumatic compression (the control group). Peripheral computerized tomographic examination was performed biweekly to measure callus area and mineral content at the fracture gap. At eight weeks, the rabbits were killed, and the biomechanical properties of the healing fractures were evaluated with a torsional test. RESULTS: An increase in callus area and mineral content at the osteotomy gap was observed in the study group, compared with the values in the control group, starting four weeks after the index procedure. At six weeks, the rabbits treated with intermittent pneumatic compression exhibited, on the average, a 32.2% larger callus area (p = 0.035) and a 49.7% higher mineral content (p = 0.01) at the osteotomy site compared with the values in the control group. The torsional stiffness, maximum torque, angular displacement at maximum torque, and energy required to failure of specimens in the study group were an average of 27.0% (p = 0.05), 61.5% (p = 0.0001), 35.4% (p = 0.0003), and 110.8% (p = 0.0001) higher, respectively, than those in the control group at eight weeks. CONCLUSIONS: Intermittent pneumatic compression enhanced callus mineralization and development and it improved the biomechanical properties of a healing osteotomy site in the rabbit tibia.

Animals↗

PubMed1989

[Study on fatigue toughness of dental materials. 1. Compressive strength on various luting cements and composite resin cores].

In this study, we investigated compressive strength of various luting cements and composite resin cores in both dry and wet condition, and then influences of repeating load on compressive strength in wet condition of distilled water at 37 degrees C. As frequency of repeating load increased, compressive strength of all materials decreased. It means that the repeated load cycling test used in this study is adequate for evaluating durability of various dental materials. The results were as follows: 1. In the condition of no loading in both dry and wet condition, resin cement indicated the highest compressive strength of all cements examined and was followed by glass ionomer cement, zinc phosphate cement and polycarboxylate cement. Glass ionomer cement was notably influenced in wet condition. 2. After 10,000 cycles of loading in wet condition, resin cement indicated the highest compressive strength again and was followed by glass ionomer cement, polycarboxylate cement and zinc phosphate cement. In particular, compressive strength of zinc phosphate cement decreased remarkably. 3. In the condition of no loading, visible light-cured composite resin core was superior to chemical one. Visible light one was notably influenced in wet condition. 4. After 10,000 cycles of loading, visible light-cured composite resin core was superior to chemical one.

Composite Resins↗

PubMed1991

Ligamentous compression of the celiac axis: CT findings in five patients.

Compression of the celiac trunk by the median arcuate ligament of the diaphragm is an uncommon angiographic and surgical finding that rarely may be symptomatic. We retrospectively reviewed contrast-enhanced abdominal CT scans in five patients with severe ligamentous compression of the celiac axis, confirmed by surgery and/or angiography, and compared the findings with those of enhanced scans of 100 consecutive patients without known ligamentous compression. In all five patients with ligamentous celiac artery compression, CT showed effacement or narrowing of the celiac trunk by an anterior soft-tissue band. Dilated peripancreatic collateral vessels were seen in four cases, and poststenotic dilatation of the distal celiac trunk was seen in two cases. The normal appearance of the vasculature was seen in the majority (76%) of the 100 control subjects, but in eight patients the celiac origin was obscured on CT scans, and in 16 patients the celiac trunk appeared narrow or effaced. Our experience suggests that severe ligamentous celiac artery compression can be identified on CT. However, the isolated CT finding of effacement or obscuration of the celiac axis occurs sufficiently often in normal patients that it is not adequate evidence to establish the diagnosis of celiac artery compression.

Aged↗

PubMed1993

Treatment of the inversion ankle sprain: comparison of different modes of compression and cryotherapy.

Relatively few studies have been performed to examine the effectiveness of different methods of treatment for the inversion ankle sprain. In this study, restoration of function following a grade II inversion sprain was compared among 34 subjects who received one of three methods of treatment, each of which incorporated an Air-Stirrup brace. The methods included uniform compression provided by elastic tape, focal compression provided by a U-shaped device, and focal compression with simultaneous cryotherapy. Although the results failed to demonstrate statistical significance at the .05 level (p = .055), the two groups that received focal compression attained each of nine levels of function in fewer days than the group that received uniform compression. The results of this study indicate that focal compression appears beneficial, but increased frequency and duration of cryotherapy does not appear to enhance the rate of recovery following an inversion ankle sprain.

Adolescent↗

PubMed1989

Phoneme perception via hearing aids with and without compression and the role of temporal resolution.

Hearing impairment is more than a sensitivity loss. The causes of reduced discrimination can be found also in deteriorations in loudness perception (recruitment), frequency resolution and temporal resolution. Only recruitment can be compensated for by modern hearing aids, namely by the reduction of the dynamic range by means of compression. However, the introduction of compression introduces temporal distortions, which may deteriorate the temporal cues of speech. In this study the perception of nonsense consonant-vowel-consonant-words presented through hearing aids was studied in a group of 12 hearing-impaired listeners. Phoneme perception in conditions with and without compression was analyzed and related to temporal parameters of the listeners' hearing. A detailed analysis of the patterns of confusions revealed clear qualitative differences in the perception of phonemes with and without compression. These differences can be related to an improved perception of temporal cues like the preburst silent interval of plosives and to spectral changes induced by the activation of the compression circuit. A reduced temporal resolution is disadvantageous for the perception of temporal cues like plosive detection, but our data do not suggest that the perception of temporal cues is hampered excessively by temporal distortions from the compression circuit itself.

Adolescent↗

PubMed1992

Effects of the fitting parameters of a two-channel compression system on the intelligibility of speech in quiet and in noise.

These experiments were carried out to assess how accurately the gains and compression ratios in a two-channel compression system needed to be set. We used as a research tool a laboratory version of a two-channel full-dynamic-range compression system. The system was initially adjusted to suit each hearing-impaired subject according to the manufacturer's recommendations. Then, further adjustments were made to ensure that speech stimuli were both audible and comfortable over a wide range of sound levels. Finally, the settings of the gains and compression ratios were systematically varied from the adjusted values and the effects of this on the intelligibility of speech in quiet and in noise (12-talker babble, levels of 65 and 75 dB SPL) were measured. The results indicated that speech reception thresholds (SRTs) in quiet were significantly adversely affected by decreases in low-level gain. However, SRTs in noise were relatively unaffected by changes in low-level gain. An exception occurred at the higher noise level used, where increases in the low-level gains (with corresponding increases in compression ratios) had a significant adverse effect on the SRTs. It is concluded that, provided excessive low-level gains (associated with high compression ratios) are avoided, the main criteria for fitting such a system should be listening comfort (i.e. achieving an acceptable tonal balance, and avoiding uncomfortably loud sounds) and an appropriate value of the threshold for detecting speech in quiet (which should be a little below 50 dB SPL).

Acoustic Stimulation↗

PubMed1999

Use of a loudness model for hearing aid fitting: III. A general method for deriving initial fittings for hearing aids with multi-channel compression.

A model for predicting loudness for people with cochlear hearing loss is applied to the problem of the initial fitting of multi-channel fast-acting compression hearing aids. The fitting is based entirely on the pure tone audiogram, and does not require measures of loudness growth. One constraint is always applied: the specific loudness pattern evoked by speech of a moderate level (65 dB SPL) should be reasonably flat (equal loudness per critical band), and the overall loudness should be similar to that evoked in a normal listener by 65-dB speech. This is achieved using the 'Cambridge' formula. For hearing aids where the compression threshold in each channel can be set to a very low value, an additional constraint is used: speech with an overall level of 45 dB SPL should be audible over its entire dynamic range in all frequency channels from 500 Hz up to about 4 kHz. For hearing aids where the compression thresholds cannot be set to very low values, a different additional constraint is used: the specific loudness pattern evoked by speech of a high level (85 dB SPL, and with the spectral characteristics of shouted speech) should be reasonably flat, and the overall loudness should be similar to that evoked in a normal listener by 85-dB speech. For both cases, compression ratios are limited to values below 3. For each of these two cases, we show how to derive compression ratios and gains, and for the first case, compression thresholds, for each channel. The derivations apply to systems with any number of channels. A computer program implementing the derivations is described. The program also calculates target insertion gains at the centre frequency of each channel for input levels of 50, 65 and 80 dB SPL, and target gains at the eardrum measured relative to the level at the reference microphone of a probe microphone system.

Auditory Threshold↗

PubMed2006

Effects of roughness and compressibility of flooring on cow locomotion.

We examined the effects of roughness and degree of compressibility of flooring on the locomotion of dairy cows. We observed 16 cows walking down specially constructed walkways with materials that differed in surface roughness and degree of compressibility. Use of a commercially available soft rubber flooring material decreased slipping, number of strides, and time to traverse the corridor. These effects were most apparent at difficult sections of the corridor, such as at the start, at a right-angle turn, and across a gutter. Covering the walkway with a thin layer of slurry increased frequency of slipping, number of strides, and time taken to traverse the walkway. Effects of adding slurry were not overcome by increasing surface roughness or compressibility. Placing more compressible materials under a slip-resistant material reduced the time and number of steps needed to traverse the corridor but did not reduce slips, and the effects on cow locomotion varied nonlinearly with the degree of compressibility of the floor. Use of commercially available rubber floors improved cow locomotion compared with concrete floors. However, standard engineering measures of the floor properties may not predict effects of the floor on cow behavior well. Increasing compressibility of the flooring on which cows walk, independently of the roughness of the surface, can improve cow locomotion.

Animals↗

PubMed1994

Compressed baled alfalfa hay for primiparous and multiparous dairy cows.

Compressed baled alfalfa hay was fed to cows, and the effects on productivity, chewing activities, and digestion were measured using a replicated 4 x 4 Latin square design. Cows received second-cutting alfalfa hay (20% CP; 40% NDF) from either compressed or standard small rectangular bales at two forage to concentrate ratios (35:65 and 65:35, DM basis). Compressed hay did not affect milk yield, although milk fat content was higher (2.90 vs. 2.68%). Higher concentrate diets increased milk yield (32.2 vs. 28.3 kg/d), lowered milk fat (2.66 vs. 2.91%), and increased milk protein (3.16 vs. 2.99%) and lactose (5.06 vs. 4.99%) with no interaction between concentrate proportion and hay type. Cows fed compressed bales spent less time eating per kilogram of DM and NDF consumed than cows fed standard bales, but rumination time was unaffected by forage processing. For cows fed both types of hay, digestibilities of DM, ADF, and NDF were similar; ruminal liquid outflow rates also were similar, but rate of particulate passage from the reticulo-rumen was greater for cows receiving compressed hay. Compressing alfalfa hay did not adversely affect forage quality but increased the ease of shipping and handling and minimized storage space requirements. This process may be beneficial when higher milk fat content is desirable or when cows have limited time to consume forage.

Animal Feed↗

PubMed2002

Compressive tolerance of the maturing cervical spine.

While a number of experiments have reported injury thresholds for the adult cervical spine in compression, the compressive failure tolerance of the child spine has not been characterized. In order to develop useful safety measures for children, the biomechanical effects of maturation must be evaluated. Hence, this study examined the effects of spinal development on the compressive mechanics of the cervical spine. An animal model was used due to the lack of human tissues in the pediatric age range. Twenty-two fresh cadaveric baboon cervical spines (all male) were dissected into two functional spinal unit segments: Occiput-C2, C3-C5, C6-T1. The specimens ranged in age from 1 to 30-human equivalent years based upon radiographic assessment of their skeletal maturity. Dynamic (1.0-m/sec) haversine displacement inputs up to 70% strain were imparted on each specimen and the resulting loads were recorded. Significant increases in the compressive failure load were observed with increased maturation of the spinal tissues (ANOVA, p = 0.003). Differences were also observed between the spinal levels examined. The lower cervical spine, C6-T1, had the smallest failure load for specimens greater than 8-human-equivalent years, while the upper cervical spine was the most susceptible to injury at less than 8-human-equivalent years. The compressive failures generated are consistent with those observed clinically, consisting of primarily burst fractures and physis (growth plate) failures. These data clearly suggest that spinal compressive tolerance is directly related to maturation. Therefore, through scaling, these data may provide tolerance values applicable to anthropomorphic test dummies and computational models aimed at injury prevention for the pediatric occupant.

Journal Article↗

PubMed2000

Effect of image compression on telepathology. A randomized clinical trial.

CONTEXT: For practitioners deploying store-and-forward telepathology systems, optimization methods such as image compression need to be studied. OBJECTIVE: To determine if Joint Photographic Expert Group (JPG or JPEG) compression, a glossy image compression algorithm, negatively affects the accuracy of diagnosis in telepathology. DESIGN: Double-blind, randomized, controlled trial. SETTING: University-based pathology departments. PARTICIPANTS: Resident and staff pathologists at the University of Illinois, Chicago, and University of Cincinnati, Cincinnati, Ohio. INTERVENTION: Compression of raw images using the JPEG algorithm. MAIN OUTCOME MEASURES: Image acceptability, accuracy of diagnosis, confidence level of pathologist, image quality. RESULTS: There was no statistically significant difference in the diagnostic accuracy between noncompressed (bit map) and compressed (JPG) images. There were also no differences in the acceptability, confidence level, and perception of image quality. Additionally, rater experience did not significantly correlate with degree of accuracy. CONCLUSIONS: For providers practicing telepathology, JPG image compression does not negatively affect the accuracy and confidence level of diagnosis. The acceptability and quality of images were also not affected.

Diagnosis, Computer-Assisted↗

PubMed1994

Large, compressive goiters treated with radioiodine.

OBJECTIVE: To evaluate the effectiveness of radioiodine therapy as an alternative for surgery in elderly patients with a large, compressive goiter using objective methods for measuring thyroid volume and tracheal compression. DESIGN: Prospective study. SETTING: University hospital in the Netherlands. PATIENTS: 19 patients (mean age +/- SD, 66 +/- 14 years) with a large, compressive multinodular goiter who had a high operative risk or refused to have thyroid surgery. INTERVENTION: A single intravenous dose of 131I at 2.6 +/- 1.0 GBq (70 +/- 28 mCi) (3.7 MBq or 100 microCi/g of thyroid tissue), followed by daily administration of L-thyroxine in doses that did not suppress thyroid-stimulating hormone. MEASUREMENTS: Clinical evaluation and measurements of thyroid volume, maximal tracheal deviation, and the smallest cross-sectional area of the tracheal lumen with magnetic resonance imaging before and 1 year after 131I treatment. RESULTS: No exacerbation of compressive symptoms after 131I therapy was observed. Thyroid volume was 269 +/- 153 mL before treatment and 154 +/- 73 mL 1 year after treatment (P < 0.001). Thyroid volume was reduced 40% +/- 15% (range, 19% to 68%). Maximal tracheal deviation (1.9 +/- 0.8 cm before and 1.5 +/- 0.7 cm 1 year after therapy) had decreased by 20% +/- 20% (range, -4% to 73%; P < 0.001), and the smallest cross-sectional area of tracheal lumen (0.78 +/- 0.38 cm2 before and 1.04 +/- 0.48 cm2 1 year after therapy) had increased by 36% +/- 38% (range, -3% to 125%; P < 0.001). Clinical signs and symptoms improved in 8 of 12 patients with dyspnea and inspiratory stridor and in both patients with compression of the superior vena cava. CONCLUSIONS: Therapy with 131I is an effective alternative to surgery for elderly patients with a large, compressive multinodular goiter.

Aged↗