BioImpedance Analysis

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Authors - R

Author Raaijmakers, E.; Faes, T.J.C.; Goovaerts, H.G.;
        Devries, P.M.J.M.; Heethaar, R.M.
Title   The inaccuracy of Kubicek's one-cylinder model in thoracic
        impedance cardiography
Journal IEEE Transactions on Biomedical Engineering
        44
        1
        JAN
Year    1997
Page    70-76
Address E Raaijmakers
        Vrije Univ Amsterdam
        Univ Hosp
        Inst Cardiovasc Deceases
        Dept Med Phys & Informat
        POB 7057
        NL-1007 MB Amsterdam, Netherlands
Serial# 0018-9294
Keys    cylinder; electrical impedance cardiography; modeling; stroke volume
Abs.    The validity of a one- and a two-cylinder model, underlying
        thoracic impedance cardiography (TIC), was investigated by
        studying the length dependence of the impedance parameters
        Z(0), (dZ/dt)(min), and stroke volume (SV). It can be shown
        that, within a one-cylinder model, all parameters are
        directly proportional to the length, whereas, if the volume
        conduction of the thorax and the neck are modeled
        separately, Z(0) and (dZ/dt)(min) are expected to be linear
        dependent and SV will be nonlinear dependent upon the
        length. The expectations were compared to results from in
        vivo measurements. Two electrode arrays were studied, in
        which the caudal recording electrode position was varied;
        SV was calculated using Kubicek's equation. Except for
        small distances, the results showed a nearly linear
        relation between the parameters and the length. Regression
        analysis of the linear part revealed statistically
        significant intercepts (p < 0.05). Neither the intercept
        nor the nonlinear part can be explained by a one-cylinder
        model, whereas a model consisting of two cylinders serially
        connected describes the experimental results accurately.
        Thus SV estimation based on a one-cylinder model is biased
        due to the invalid one cylinder model. Corrections for the
        Kubicek-equation need to be developed in future research
        using this two-cylinder model.

Record, P.; Wang, M.; Dickin, F.
Title   Conducting boundary strategy: A new technique for medical EIT
Journal Physiological Measurement
        16
         Suppl. 3A
        AUG
Year    1995
Page    A249-A255
Address P Record
        Keele Univ
        Hosp Ctr
        Dept Biomed Engn & Med Phys
        Thornburrow Dr
        Stoke on Trent ST4 7QB
        Staffs, England
Serial# 0967-3334
Abs.    A medical application of a new measurement strategy
        developed for process tomography is presented. By
        exchanging the current streamlines with the equipotential
        lines impedance tomography can be performed using unipolar
        measurements. The equipotential lines are now parallel to
        the conducting boundary and voltage measurement is made
        between this boundary and an insulated electrode. A set of
        32 electrodes was placed around the chest with every
        alternate electrode connected to form the 'conducting
        boundary'. A total of 120 independent measurements were
        available. Reciprocity error without common mode feedback
        was 0.5% with a dynamic range of only 1:1.12. The images
        were comparable to that reconstructed using adjacent drive
        strategy.

Reilly, J.J.; Wilson, J.; Mccoll, J.H.; Carmichael, M.;
        Durnin, J.V.G.A.
Title   Ability of biolectric impedance to predict fat-free mass in
        prepubertal children
Journal Pediatric Research
        39
        1
        JAN
Year    1996
Page    176-179
Address JJ Reilly
        Univ Glasgow
        Yorkhill Hosp
        Dept Human Nutr
        Glasgow G3 8SJ
        Lanark, Scotland
Serial# 0031-3998
Keys    BODY-COMPOSITION ASSESSMENT; BIOELECTRICAL-IMPEDANCE; CROSS-
        VALIDATION; SKINFOLD-THICKNESS; DENSITY; HYDRATION; ADULTS
Abs.    Measurements of body composition are being made
        increasingly widely in pediatrics. Tetrapolar whole body
        impedance (BI) is particularly suitable as a method of
        estimating body composition in children and is therefore
        the subject of great interest at present. However, the
        ability of BI to accurately estimate fat-free mass (FFM) in
        children is unclear, and users of BI are faced with a
        growing choice of prediction equations for estimation of
        FFM. Studies in adults have suggested that choice of
        prediction equation can have a profound effect on the
        estimate obtained, The aim of the present study was to
        measure the ability of four published pediatric BI
        equations to predict FFM in 98 Caucasian prepubertal
        children (mean age 9.0 y). For three of the published
        equations, limits of agreement between predicted and
        reference FFM were wide and distinct biases were apparent.
        With mean FFM of 25 kg, the equation of L. Cordain et al.
        overestimated reference FFM (95% CI +2.1 to +3.1 kg),
        whereas those of P. Deurenberg ct al. (95% CI -1.9 to -2.9
        kg) and F. Schaefer ct al. (95% CI -1.4 to -2.5 kg)
        systematically underestimated reference FFM. The equation
        of Houtkooper et al. (95% CI -0.2 to +0.8 kg) predicted FFM
        with negligible bias and had narrower limits of agreement
        relative to the reference method than the other three
        equations tested. We conclude that the ability of BI to
        predict body composition in children depends on the
        equation chosen and that the general applicability of BI
        equations cannot be safely assumed. Cross-validation of BI
        equations is recommended before they are used routinely for
        estimation of body composition in children.

Rigaud, B.; Hamzaoui, L.; Frikha, M.R.; Chauveau, N.;
        Morucci, J.P.
Title   In vitro tissue characterization and modelling using
        electrical impedance measurements in the 100 Hz-10 MHz
        frequency range
Journal Physiological Measurement
        16
         Suppl. 3A
        AUG
Year    1995
Page    A15-A28
Address B Rigaud
        Univ Toulouse 3
        Ctr Hosp Hotel Dieu
        Inserm
        U305
        F-31052 Toulouse, France
Serial# 0967-3334
Abs.    In vitro electrical impedance spectrometry was performed on
        tissue samples excised from sheep. Measured data have been
        processed to reduce dispersion in measurements and to
        provide criteria useful for tissue comparison. Two
        electrical models are proposed for tissues exhibiting a one-
        circle impedance locus and a two-circle impedance locus.
        Measurement results and electrical parameters of tissues
        and models fitted to experimental data are presented. Model
        sensitivity to parameter variations is discussed.

Rippe-B
Pathophysiological description of the ultrastructural changes of
the peritoneal membrane during long-term continuous ambulatory
peritoneal dialysis.
Blood Purification 12(4-5): 211-220
1994
English
Some of the patients on continuous ambulatory peritoneal dialysis (
CAPD) develop with time on treatment an increased transperitoneal
transport of small solutes, implying that glucose is more rapidly
absorbed from the dialysate. Hence, the dialysate/serum
crystalloid osmotic gradient dissipates at a faster rate, so that
ultrafiltration failure may result. The pathophysiological
correlates to these changes are not well understood. However it
seems that with time on CAPD, there are changes in the
submesothelial interstitium, affecting both the ground substance
and spacing and orientation of collagen fibers. There may also be
mesothelial alterations with patchy shedding of the cells. The
present article discusses these changes in terms of a modified
three-pore model of peritoneal permeability. In this model, the
capillary walls act as a major barrier for solutes ranging in size
from inulin (molecular radius 14 ANG ) to macromolecules (
molecular radius gt 30 ANG ). However, for solutes smaller than
inulin both capillary wall and interstitium contribute to the
blood-peritoneum transport impedance. The increased small-solute
exchange sometimes occurring in long-term CAPD can be explained
either by recruitment of vascular surface area, due, e.g., to an
increased capillarization of the peritoneal membrane with time,
or, more likely, a drop in the interstitial transport resistance
to small solutes. The latter possibility is supported by the often
more pronounced increase in the transperitoneal transfer of small
solutes than that of macromolecules over time in CAPD.

Riu, P.J.; Bragos, R.; Rosell, J.
Title   Broadband quasi-differential multifrequency electrical
        impedance imaging system
Journal Physiological Measurement
        17
         Suppl. 4A
        NOV
Year    1996
Page    A39-A47
Address PJ Riu
        Univ Politecn Catalunya
        Dept Elect Engn
        C Gran Capita S-N
        Modul C4
        E-08034 Barcelona, Spain
Serial# 0967-3334
Keys    TOMOGRAPHY
Abs.    Dynamic and multifrequency imaging methods have been
        demonstrated both theoretically and experimentally.
        Multifrequency methods are able to produce images of static
        structures inside the measured object. Data collection
        systems, however, are affected by errors due to their non-
        ideal frequency behaviour. If the frequencies used in the
        measurement were close enough, the system would behave in
        almost the same way. In this case, however, the impedance
        change displayed by biological tissues is small, so the
        situation is similar to dynamic imaging. We call this
        method the quasi-differential imaging method.
        We have designed and built an instrument able to apply
        signals from 1 kHz to 1 MHz, with frequency increments of
        10 Hz. Patient interface circuits and demodulators were
        designed to display a fat response in the full frequency
        range of operation. Signals are digitized with 16 bit
        resolution and sent to the host computer using a high-speed
        serial interface. This allows a maximum measurement speed
        of about 8 images/s.
        All the system parts were full characterized out of the
        system and the results of these measurements are given as
        an indication of the limits of its use as a quasi-static
        imaging or quasi-differential imaging data collection
        system.

Riu, P.J.; Rosell, J.; Lozano, A.; Pallasareny, R.
Title   Multi-frequency static imaging in electrical impedance
        tomography .1. Instrumentation requirements
Journal Medical & Biological Engineering & Computing
        33
        6
        NOV
Year    1995
Page    784-792
Address PJ Riu
        Univ Politecn Catalunya
        Dept Electr Engn
        Div Instrumentacio & Bioengn
        C Gran Capita S-N Modul C4
        E-08034 Barcelona, Spain
Serial# 0140-0118
Keys    electrical impedance tomography; multi-frequency; static
        imaging
        DIELECTRIC-PROPERTIES; BIOLOGICAL-MATERIALS
Abs.    Static images of the human body using electrical impedance
        tomography techniques can be obtained by measuring at two
        or more different frequencies. The frequencies used depend
        on the application, and their selection depends on the
        frequency behaviour of the impedance for the target tissue.
        An analysis using available data and theoretical models for
        tissue impedance yields the expected impedance and boundary
        voltage changes, therefore setting the measurement
        instrument specifications. The instrument errors produced
        by different sources are analysed, and, from this analysis
        it is possible to determine the feasibility of building the
        instrument, the limit values for some parameters (or
        components) and indications on the most suitable design of
        critical parts. This analysis also shows what kinds of
        error can be expected in the reconstructed images. It is
        concluded that it is possible to build an instrument with
        limited errors, allowing static images to be obtained. An
        instrument has been built that meets some of the design
        requirements and fails in others because of technological
        problems. In vivo images obtained with this instrument will
        be presented in Part 2 of this work.

Robinson, T.L.; Snowharter, C.; Taaffe, D.R.; Gillis, D.;
        Shaw, J.; Marcus, R.
Title   Gymnasts exhibit higher bone mass than runners despite
        similar prevalence of amenorrhea and oligomenorrhea
Journal Journal of Bone and Mineral Research
        10
        1
        JAN
Year    1995
Page    26-35
Address C Snowharter
        Oregon State Univ
        Dept Exercise & Sport Sci
        Bone Res Lab
        Corvallis, OR 97331 USA
Serial# 0884-0431
Keys    MINERAL DENSITY; MENSTRUAL DYSFUNCTION; DISTANCE RUNNERS;
        BODY-COMPOSITION; YOUNG-WOMEN; EXERCISE; HISTORY; GIRLS; MEN
Abs.    Female athletes exhibit a higher prevalence of exercise-
        associated amenorrhea and oligomenorrhea compared with
        nonathletic women, and both conditions are related to
        reduced bone mineral density (BMD), particularly at the
        spine. This study investigated bone mass and oligomenorrhea
        and amenorrhea in two groups of competitive female athletes
        with different skeletal loading patterns: gymnasts and
        runners. Bone mineral density (g/cm(2)) of the femoral neck,
        lumbar spine (L2-4), and whole body was assessed by dual
        energy X-ray absorptiometry (QDR-1000/W, Hologic Inc.,
        Waltham, MA) in collegiate gymnasts (n = 21) and runners (n
        = 20), and nonathletic college women (n = 19). The runners
        and gymnasts had similar values for percent body fat (14.7
        +/- 2.2% and 15.6 +/- 2.9%, respectively), which were lower
        (p < 0.001) than controls (22.3 +/- 3.0%). Lean body mass
        (LBM) did not differ among the groups, but when adjusted
        for body surface area, gymnasts had a higher LBM/height(2)
        (p = 0.0001) compared with runners and controls. Muscle
        strength was significantly greater (p < 0.05) in gymnasts
        for quadriceps, biceps, and hip adductor force, compared
        with runners and controls. Gymnasts had a significantly
        later menarche age (16.2 +/- 1.7 years) compared with
        runners (14.4 +/- 1.7 years) and controls (13.0 +/- 1.2
        years). The prevalence of oligo- and amenorrhea was 47% for
        gymnasts (6 amenorrheic, 4 oligomenorrheic), 30% for
        runners (3 amenorrheic, 3 oligomenorrheic), and 0% for
        controls. Furthermore, athletic groups had similar
        menstrual histories given the higher proportion of gymnasts
        who had experienced primary amenorrhea. When evaluated
        since menarche, however, runners had somewhat longer
        histories due to an earlier age at menarche and slightly
        older ages. Dietary calcium intake did not differ among
        groups, although mean values were below the RDA of 1200
        mg/day. By athletic group, BMD at any site did not differ
        among women with amenorrhea versus oligomenorrhea versus
        eumenorrhea, although there was a trend for the regularly
        menstruating athletes in both groups to have slightly
        higher values. Lumbar spine BMD was lower (p = 0.0001) in
        runners (0.98 +/- 0.11 g/cm(2)) compared with both gymnasts
        and controls (1.17 a 0.13 and 1.11 +/- 0.11 g/cm(2),
        respectively). Femoral neck BMD differed among all groups
        (p = 0.0001): gymnasts = 1.09 +/- 0.12 g/cm(2) > controls =
        0.97 +/- 0.10 g/cm(2) > runners = 0.88 +/- 0.11 g/cm(2).
        Whole body BMD was lower (p < 0.01) in runners (1.04 +/-
        0.06 g/cm(2)) compared with gymnasts and controls (1.11 +/-
        0.08 and 1.09 +/- 0.06 g/cm(2), respectively). When
        adjusted for estimated bone size, lumbar spine and femoral
        neck bone mineral apparent density (BMAD, g/cm(3)) differed
        (p = 0.0001) among all groups: gymnasts > controls >
        runners. In conclusion: (1) gymnasts exhibited higher
        femoral neck BMD than runners and controls as well as a
        later age at menarche and a slightly higher
        (nonsignificant) prevalence of oligo- and amenorrhea; (2)
        runners exhibited lower BMD values compared with gymnasts
        despite similar current and historical menstrual cycle
        patterns; and (3) the mechanical forces generated from high
        impact loading and muscular contraction during gymnastics
        training have powerful osteogenic effects, which appear to
        counteract the increased bone resorption that has been
        shown to result from oligo- and amenorrhea.

Roche-A-F; Siervogel-R-M
Measures of body composition: Their relationship to blood pressure
and use in epidemiologic research.
Annals of Epidemiology 1(4): 313-319
1991
English
The association between "overweight" and increased risk of high
blood pressure has long been recognized. The quantification of
overweight into various aspects of body composition and the
relationships of these aspects to blood pressure remain important
areas of current research. The manner in which adipose tissue is
distributed over the body is proving to be another important risk
factor. Methodologies for assessing body composition include a
variety of approaches commonly used in epidemiologic studies,
ranging from simple indices (e.g., body mass index) to estimation
of total body fat mass from equations based on skinfolds and other
anthropometry, to newer approaches incorporating bioelectric
impedance. Refined Laboratory methods for assessing body
composition are important in the study of small groups and in the
development of predictive equations. These refined methods include
the traditional approaches of hydrostatic weighing and K-40
determinations, as well as newer improvements on these techniques
incorporating estimates of bone mineral content and total body
water. Other new sophisticated methodologies include dual-energy
x-ray absorptiometry and nuclear magnetic resonance imaging. The
approach to assessing body composition may vary among age groups;
methodologies applicable to children may not work for the elderly.

Royall, D.; Jeejeebhoy, K.N.; Oconnor, B.; Taylor, B.R.;
        Langer, B.; Mcleod, R.S.
Title   Nutritional status and function in patients following Whipple
        procedure compared with controls
Journal Journal of the American College of Nutrition
        15
        1
        FEB
Year    1996
Page    73-78
Address KN Jeejeebhoy
        Univ Toronto
        Dept Med
        RM 6352
        Med Sci Bldg
        Toronto
        on M5S 1A8, Canada
Serial# 0731-5724
Keys    nutritional assessment; skeletal muscle function; Whipple
        procedure; bioelectric impedance analysis
        TOTAL PANCREATECTOMY; PANCREATICODUODENECTOMY; INSUFFICIENCY;
        PYLORUS; BODY
Abs.    Objective: Despite the potential for nutritional deficits
        in patients undergoing pancreaticoduodenectomy or Whipple
        procedure, long-term assessment of nutritional status has
        largely been ignored. This study assessed nutritional
        status of 24 Whipple patients compared with matched post-
        cholecystectomy controls. Methods: Clinical assessment was
        by subjective global assessment, body composition was
        assessed by bioelectric impedance analysis and functional
        assessment was by respiratory muscle strength and skeletal
        muscle function performed by electrical stimulation of the
        ulnar nerve of the wrist and hand-grip dynamometry.
        Results: Whipple patients studied 4.6 +/- 0.7 years since
        surgery and controls (4.8 +/- 0.7 years since surgery) were
        all judged clinically to be in a good nutritional state.
        Compared with controls, Whipple patients had significantly
        lower body weight (Whipple: 72.5 +/- 2.8 kg, control: 83.9
        +/- 3.3 kg, p < 0.05) however, the mean body weight of both
        Whipple and controls was above ideal weight (Whipple: 113.3
        +/- 4.3%, control: 122.3 +/- 3.7% p = NS). No significant
        differences in functional performance were observed between
        groups. Energy intake of Whipple and controls was also
        comparable. In the Whipple group, neither the extent of
        gastric resection or the pathological diagnosis had an
        effect on the nutritional parameters studied. Conclusions:
        Long-term follow-up of patients having undergone Whipple
        procedure failed to reveal the presence of any nutritional
        or functional deficits suggesting that a full nutritional
        recovery is possible after this surgery.

Ruiztorres, A.; Vicent, D.; Depaco, G.S.; Munoz, F.J.;
        Gimeno, A.; Carraro, R.
Title   Increase in insulin secretion with age: Its clinical
        importance in evaluating abnormal secretions focused on
        diabetes type II and obesity
Journal Archives of Gerontology and Geriatrics
        22
        1
        JAN-FEB
Year    1996
Page    39-47
Address A Ruiztorres
        Univ Autonoma Madrid
        Hosp Princesa
        Inst Invest Gerontol & Metab
        Diego Leon 62
        E-28006 Madrid, Spain
Serial# 0167-4943
Keys    ageing; insulin secretion; C-peptide excretion; diabetes type
        II; obesity; energy intake
        BETA-CELL FUNCTION; C-PEPTIDE; BODY-COMPOSITION; GROWTH-
        HORMONE; MELLITUS; RATES
Abs.    The urinary C-peptide excretion was measured in a healthy
        standardized population sample of 160 subjects from 20 to
        90 years of age, homogeneously distributed by age and sex.
        Urinary C-peptide excretion corresponded to 7% of the total
        amount released. The daily C-peptide excretion was 61.23 +/-
        2.2 (S.E.) mu g in the whole sample which corresponds to
        41.9 +/- 1.5 IU of insulin secreted/day (I(CP)(d)), without
        sex differences. There is an increase of the I(CP), value
        from the young to the healthy middle-aged person, but when
        the results were corrected for standard amounts of excreted
        creatinine (1 g) and urea (22 g) the age-dependent increase
        is to be observed during the whole adult life span.
        Assuming that cross-sectionally observed data are
        representative of the individual changes, it is concluded
        that age alone increases insulin secretion. The results
        which may be useful as reference values for clinical
        application were as follows: (A) in 5 diabetes type II
        patients in which the I(CP)(d) value was measured several
        times a week, the intraindividual variation coefficient was
        10.9 +/- 7.2%; (B) in a sample of 47 type II diabetic
        patients of both sexes, between 51 and 70 years of age, a
        clear correlation was found between I(CP)(d) and the
        results of the glucagon stimulation test, mainly regarding
        the relationship between I(CP)(d) and the planimetrically
        measured area under the curve (r = 0.7, P < 0.0001); (C) in
        7 obese non-diabetic individuals of similar ages the
        influence of the hypocaloric diet on the I(CP)(d) value was
        more evident than the use of C-peptide blood determinations
        before or after glucagon. Finally, the I(CP)d values of
        type II diabetes patients with insulin requirement (n = 27)
        were significantly lower than in the healthy control group
        (31.1 +/- 24.0 vs. 45.0 +/- 20.4), while diabetic patients
        without insulin requirement showed significantly higher
        values (73.0 +/- 33.0) (n = 27). These clinical studies
        primarily focused on the physiology of human ageing justify
        the measurement of C-peptide urinary excretion for
        evaluating daily insulin secretion in patients with type II
        diabetes.

Ryan-C-F; Love-L-L; Buckley-P-A
Energy expenditure in obstructive sleep apnea.
Sleep (Rochester) 18(3): 180-187
1995
English
Patients with obstructive sleep apnea (OSA) are often obese and,
in common with obese patients generally, find it difficult to lose
weight. Obstructive sleep apnea may be associated with changes in
total daily energy expenditure that could contribute to obesity
and complicate its management. To determine whether resting
metabolic rate and the thermogenic effect of food are reduced in
OSA, we have compared postabsorptive resting energy expenditure (
REE) and dietary thermogenesis (DT) in 14 patients with moderate
to severe symptomatic OSA and 14 control subjects matched for
obesity. Anthropometrics, body composition analysis using
bioelectrical impedance and indirect calorimetry using a metabolic
cart and canopy system were performed in all subjects. Dietary
thermogenesis after a liquid meal equivalent to 35% of REE was
measured in 13 patients and 8 control subjects. Measurements were
repeated after chronic (mean +- SD 12 +- 5 weeks) nasal continuous
positive airway pressure (CPAP) therapy in 10 patients with OSA.
Energy expenditure was expressed in terms of metabolic body size.
The patients with OSA were heavier and had larger necks and a
larger lean body mass (LBM) than controls, but the two groups were
well matched for body mass index (BMI) and percent body fat. REE
was greater in OSA patients than controls, but when corrected for
LBM there was no difference between the two groups (27 +- 3 vs. 28
+- 4 kcal/kg). DT was similar in patients and controls (17 +- 6
vs. 15 +- 10%). REE/LBM was quite consistent among patients with
OSA, regardless of body weight. REE and DT did not change
following chronic nasal CPAP therapy. Resting energy expenditure
was related to LBM (r = 0.76; p lt 0.001) but not apnea + hypopnea
index (r = 0.11). We conclude that REE and DT are not reduced in
obese patients with moderate to severe symptomatic OSA. These
findings suggest that patients with OSA have a pattern of obesity
characterized by energy homeostasis at an elevated body weight
set-point.

Ryuko, K.; Takahashi, K.; Okada, M.; Tamaru, N.; Kitao, M.
Title   Cardiac output measurement by thoracic electrical
        bioimpedance in a patient with ovarian hyperstimulation
        syndrome
Journal Gynecologic and Obstetric Investigation
        41
        2
        MAR-APR
Year    1996
Page    140-142
Address K Ryuko
        Shimane Med Univ
        Dept Obstet & Gynecol
        89-1 Enya CHO
        Izumo
        Shimane 693, Japan
Serial# 0378-7346
Keys    ovarian hyperstimulation syndrome; thoracic bioimpedance;
        cardiac output
        STROKE VOLUME
Abs.    A 31-year-old woman developed severe ovarian
        hyperstimulation syndrome (OHSS) after exogenous
        gonadotropin stimulation for an in vitro fertilization
        program. Because of refusal of invasive monitoring,
        thoracic electrical bioimpedance (TEE) was performed to
        evaluate cardiac function and volume status. TEE pointed
        out decreased cardiac output (GO: 4.23 liters/min), cardiac
        index (CI: 2.63) and stroke volume (SV: 57.5 ml/beat).
        Serial monitoring of hemodynamic variables was then
        performed. After the data were obtained, fluid management
        was performed, and the patient recovered from abnormal
        homeostasis in 3 days. The hemodynamic variables returned
        to the normal range (GO: 6.85 liters/min, CI: 4.25, SV:
        100.5 ml/beat) within the first 24 h. There were no
        complications such as life-threatening multiple organ
        failure. We discuss the usefulness of TEE for the fluid
        management of severe OHSS, as well as its implications.

Ryuko, K.; Takahashi, K.; Okada, M.; Tamaru, N.; Kitao, M.
Cardiac output measurement by thoracic electrical
bioimpedance in a patient with ovarian hyperstimulation
syndrome
Gynecologic and Obstetric Investigation
41
2
MAR-APR
1996
140-142
K Ryuko
Shimane Med Univ
Dept Obstet & Gynecol
89-1 Enya CHO
Izumo
Shimane 693, Japan
0378-7346
ovarian hyperstimulation syndrome; thoracic bioimpedance;
cardiac output
STROKE VOLUME
A 31-year-old woman developed severe ovarian
hyperstimulation syndrome (OHSS) after exogenous
gonadotropin stimulation for an in vitro fertilization
program. Because of refusal of invasive monitoring,
thoracic electrical bioimpedance (TEE) was performed to
evaluate cardiac function and volume status. TEE pointed
out decreased cardiac output (GO: 4.23 liters/min), cardiac
index (CI: 2.63) and stroke volume (SV: 57.5 ml/beat).
Serial monitoring of hemodynamic variables was then
performed. After the data were obtained, fluid management
was performed, and the patient recovered from abnormal
homeostasis in 3 days. The hemodynamic variables returned
to the normal range (GO: 6.85 liters/min, CI: 4.25, SV:
100.5 ml/beat) within the first 24 h. There were no
complications such as life-threatening multiple organ
failure. We discuss the usefulness of TEE for the fluid
management of severe OHSS, as well as its implications.