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Terms modified by Supine Selected AbstractsInfluence of concurrent exercise or nutrition countermeasures on thigh and calf muscle size and function during 60 days of bed rest in womenACTA PHYSIOLOGICA, Issue 2 2007T. A. Trappe Abstract Aim:, The goal of this investigation was to test specific exercise and nutrition countermeasures to lower limb skeletal muscle volume and strength losses during 60 days of simulated weightlessness (6° head-down-tilt bed rest). Methods:, Twenty-four women underwent bed rest only (BR, n = 8), bed rest and a concurrent exercise training countermeasure (thigh and calf resistance training and aerobic treadmill training; BRE, n = 8), or bed rest and a nutrition countermeasure (a leucine-enriched high protein diet; BRN, n = 8). Results:, Thigh (quadriceps femoris) muscle volume was decreased (P < 0.05) in BR (,21 ± 1%) and BRN (,24 ± 2%), with BRN losing more (P < 0.05) than BR. BRE maintained (P > 0.05) thigh muscle volume. Calf (triceps surae) muscle volume was decreased (P < 0.05) to a similar extent (P > 0.05) in BR (,29 ± 1%) and BRN (,28 ± 1%), and this decrease was attenuated (P < 0.05) in BRE (,8 ± 2%). BR and BRN experienced large (P < 0.05) and similar (P > 0.05) decreases in isometric and dynamic (concentric force, eccentric force, power and work) muscle strength for supine squat (,19 to ,33%) and calf press (,26 to ,46%). BRE maintained (P > 0.05) or increased (P < 0.05) all measures of muscle strength. Conclusion:, The nutrition countermeasure was not effective in offsetting lower limb muscle volume or strength loss, and actually promoted thigh muscle volume loss. The concurrent aerobic and resistance exercise protocol was effective at preventing thigh muscle volume loss, and thigh and calf muscle strength loss. While the exercise protocol offset ,75% of the calf muscle volume loss, modification of this regimen is needed. [source] Twenty-four-hour non-invasive monitoring of systemic haemodynamics and cerebral blood flow velocity in healthy humansACTA PHYSIOLOGICA, Issue 1 2002M. DIAMANT ABSTRACT Acute short-term changes in blood pressure (BP) and cardiac output (CO) affect cerebral blood flow (CBF) in healthy subjects. As yet, however, we do not know how spontaneous fluctuations in BP and CO influence cerebral circulation throughout 24 h. We performed simultaneous monitoring of BP, systemic haemodynamic parameters and blood flow velocity in the middle cerebral artery (MCAV) in seven healthy subjects during a 24-h period. Finger BP was recorded continuously during 24 h by Portapres and bilateral MCAV was measured by transcranial Doppler (TCD) during the first 15 min of every hour. The subjects remained supine during TCD recordings and during the night, otherwise they were seated upright in bed. Stroke volume (SV), CO and total peripheral resistance (TPR) were determined by Modelflow analysis. The 15 min mean value of each parameter was assumed to represent the mean of the corresponding hour. There were no significant differences between right vs. left, nor between mean daytime vs. night time MCAV. Intrasubject comparison of the twenty-four 15-min MCAV recordings showed marked variations (P < 0.001). Within each single 15-min recording period, however, MCAV was stable whereas BP showed significant short-term variations (P < 0.01). A day,night difference in BP was only observed when daytime BP was evaluated from recordings in the seated position (P < 0.02), not in supine recordings. Throughout 24 h, MCAV was associated with SV and CO (P < 0.001), to a lesser extent with mean arterial pressure (MAP; P < 0.005), not with heart rate (HR) or TPR. These results indicate that in healthy subjects MCAV remains stable when measured under constant supine conditions but shows significant variations throughout 24 h because of activity. Moreover, changes in SV and CO, and to a lesser extent BP variations, affect MCAV throughout 24 h. [source] Linear and nonlinear measures of blood pressure variability: Increased chaos of blood pressure time series in patients with panic disorderDEPRESSION AND ANXIETY, Issue 2 2004Vikram K. Yeragani M.B.B.S. Abstract Arterial blood pressure (BP) variability increases progressively with the development of hypertension and an increase in BP variability is associated with end organ damage and cardiovascular morbidity. On the other hand, a decrease in heart rate (HR) variability is associated with significant cardiovascular mortality. There is a strong association between cardiovascular mortality and anxiety. Several previous studies have shown decreased HR variability in patients with anxiety. In this study, we investigated beat-to-beat variability of systolic and diastolic BP (SBP and DBP) in normal controls and patients with panic disorder during normal breathing and controlled breathing at 12, and 20 breaths per minute using linear as well as nonlinear techniques. Finger BP signal was obtained noninvasively using Finapres. Standing SBPvi and DBP BPvi (log value of BP variance corrected for mean BP divided by HR variance corrected for mean HR) were significantly higher in patients compared to controls. Largest Lyapunov exponent (LLE) of SBP and DBP, a measure of chaos, was significantly higher in patients in supine as well as standing postures. The ratios of LLE (SBP/HR) and LLE (DBP/HR) were also significantly higher (P < .001) in patients compared to controls. These findings further suggest dissociation between HR and BP variability and a possible relative increase in sympathetic function in anxiety. This increase in BP variability may partly explain the increase in cardiovascular mortality in this group of patients. Depression and Anxiety 19:85-95, 2004. © 2004 Wiley-Liss, Inc. [source] Low prevalence of cardiac autonomic neuropathy in Type 1 diabetic patients without nephropathyDIABETIC MEDICINE, Issue 8 2001J. A. Meinhold Abstract Aim To assess the prevalence of cardiac autonomic neuropathy (CAN) in Type 1 diabetic patients with and without nephropathy. Methods Sixty-six consecutive patients without nephropathy (n = 24), with incipient (n = 26) or overt nephropathy (n = 16) and a diabetes duration between 21 and 31 years were examined. Heart rate variability (HRV) as measure for CAN was investigated with short-term spectral analysis in the low-frequency (LF) band (0.06,0.15 Hz), reflecting sympathetic and vagal activity, and high-frequency (HF) band (0.15,0.50 Hz), reflecting vagal activity. HRV was expressed as spectral power (ms2, log-transformed). Normal, age-corresponding reference values were established in 184 controls. QTc intervals and dispersion were measured. Results After adjustment for age, there was no significant difference between healthy controls and patients without nephropathy. After further adjustment for diabetes duration, HbA1c, hypertension and treatment with ,-blockers, HRV in both frequency bands decreased with evidence of nephropathy. LF band (supine): patients without nephropathy 5.56 (4.89,6.21) (least squares means and 95% confidence interval (CI)), incipient nephropathy 5.72 (5.15,6.29) and overt nephropathy 4.11 (3.27,4.96). HF band (supine): without nephropathy 5.93 (5.26,6.60), incipient nephropathy 5.99 (5.41,6.57) and overt nephropathy 4.84 (4.00,5.68). Significant differences were found for patients without and with incipient nephropathy compared with those with overt nephropathy in the LF band and between patients with incipient nephropathy compared with those with overt nephropathy in the HF band. QTc intervals and QTc dispersion increased significantly with increasing nephropathy. Conclusions Long-term Type 1 diabetes without nephropathy was not associated with impaired cardiac autonomic function in our study. However, in those with nephropathy, a loss of both vagal and sympathetic activity was present, and the severity of CAN correlated positively with more advanced nephropathy. Diabet. Med. 18, 607,613 (2001) [source] Outcomes after laparoscopic Nissen fundoplication are not influenced by the pattern of refluxDISEASES OF THE ESOPHAGUS, Issue 2 2008A. T. Meneghetti SUMMARY., The purpose of this study was to compare the outcomes of patients with different types of gastroesophageal reflux disease (upright, supine, or bipositional) after laparoscopic Nissen fundoplication and determine if patients with upright reflux have worse outcomes. Two hundred and twenty-five patients with reflux confirmed by 24-h pH monitoring were divided into three groups based on the type of reflux present. Patients were questioned pre- and post-fundoplication regarding the presence and duration of symptoms (heartburn, regurgitation, dysphagia, cough and chest pain). Symptoms were scored using a 5-point scale, ranging from 0 (no symptom) to 4 (disabling symptom). Esophageal manometry and pH results were also compared. There was no statistically significant difference in lower esophageal sphincter length, pressure or function between the three groups. There was no significant difference in any of the postoperative symptom categories between the three groups. The type of reflux identified preoperatively does not have an adverse effect on postoperative outcomes after Nissen fundoplication and should not discourage physicians from offering antireflux surgery to patients with upright reflux. [source] The Effect of Hemodialysis on Left Ventricular Outflow Tract GradientECHOCARDIOGRAPHY, Issue 6 2010Pawel Petkow Dimitrow M.D. Background: The aim of the study was to assess the effect of hemodialysis (HD) on left ventricular outflow tract gradient (LVOTG) measured both in supine and upright position (provocative maneuver to unload LV cavity by rapid preload reduction). Supine/standing echocardiography was performed immediately before and immediately after HD. For additional verification of the hypothesis about preload-dependence of LVOTG, the echocardiograms after long (2-day delay HD due to weekend) versus short (usual 1-day) pause between HDs were compared. Methods: Forty-one patients on chronic HD (mean age 44 ± 11 years) were examined using a portable hand-carried echocardiograph. In accordance with the prestudy assumption the ultrafiltration volume was significantly greater during HD after a long pause in comparison to HD after a short pause (3707 ± 2826 mL vs. 2665 ± 1152 mL P < 0.05). Results: After a long pause, the mean value of LVOTG at the pre-HD was mildly increased in the supine position and remained at a similar level in the upright position (13.1 ± 6.1 vs. 13.6 ± 9.1 mmHg). Mean LVOTG at the post-HD in the supine position was similar to pre-HD, however the orthostatic stress test induced a significant increase of LVOTG (13.9 ± 15.2 vs. 18.2 ± 19.9 mmHg P < 0.05). After a short pause at the pre-HD the LVOTG in the supine position and after the orthostatic provocation was very similar to measurements after long pause (13.3 ± 9.1 vs. 13.3 ± 10.8 mmHg). At the post-HD the mean value of LVOTG increased during upright posture but the differences were of borderline significance (13.2 ± 6.6 vs. 17.9 ± 18.6 mmHg P = 0.052). Conclusions: HD predisposed to standing-provoked LVOTG especially when a long pause (2 days) between HDs induced a greater weight gain and subsequently a larger volume of ultrafiltration was needed to reduce hypervolemia. (Echocardiography 2010;27:603-607) [source] Modelflow estimates of cardiac output compared with Doppler ultrasound during acute changes in vascular resistance in womenEXPERIMENTAL PHYSIOLOGY, Issue 4 2010Kenneth S. Dyson We compared Modelflow (MF) estimates of cardiac stroke volume (SV) from the finger pressure-pulse waveform (Finometer®) with pulsed Doppler ultrasound (DU) of the ascending aorta during acute changes in total peripheral resistance (TPR) in the supine and head-up-tilt (HUT) postures. Twenty-four women were tested during intravenous infusion of 0.005 or 0.01 ,g kg,1 min,1 isoprenaline, 10 or 50 ng kg,1 min,1 noradrenaline and 0.3 mg sublingual nitroglycerine. Responses to static hand-grip exercise (SHG), graded lower body negative pressure (LBNP, from ,20 to ,45 mmHg) and 45 deg HUT were evaluated on separate days. Bland,Altman analysis indicated that SVMF yielded lower estimates than SVDU during infusion of 0.01 ,g kg,1 min,1 isoprenaline (SVMF 92.7 ± 15.5 versus SVDU 104.3 ± 22.9 ml, P= 0.03) and SHG (SVMF 78.8 ± 12.0 versus SVDU 106.1 ± 28.5 ml, P < 0.01), while larger estimates were recorded with SVMF during ,45 mmHg LBNP (SVMF 52.6 ± 10.7 versus SVDU 46.2 ± 14.5 ml, P= 0.04) and HUT (SVMF 59.3 ± 13.6 versus SVDU 45.2 ± 11.3 ml, P < 0.01). Linear regression analysis revealed a relationship (r2= 0.41, P < 0.01) between the change in TPR from baseline and the between-methods discrepancy in SV measurements. This relationship held up under all of the experimental protocols (regression for fixed effects, P= 0.46). These results revealed a discrepancy in MF estimates of SV, in comparison with those measured by DU, during acute changes in TPR. [source] Body Position and Cardiac Dynamic and Chronotropic Responses to Steady-State Isocapnic Hypoxaemia in HumansEXPERIMENTAL PHYSIOLOGY, Issue 2 2000S. Deborah Lucy Neural mediation of the human cardiac response to isocapnic (IC) steady-state hypoxaemia was investigated using coarse-graining spectral analysis of heart rate variability (HRV). Six young adults were exposed in random order to a hypoxia or control protocol, in supine and sitting postures, while end-tidal PCO2 (PET,CO2) was clamped at resting eucapnic levels. An initial 11 min period of euoxia (PET,O2 100 mmHg; 13.3 kPa) was followed by a 22 min exposure to hypoxia (PET,O2 55 mmHg; 7.3 kPa), or continued euoxia (control). Harmonic and fractal powers of HRV were determined for the terminal 400 heart beats in each time period. Ventilation was stimulated (P < 0.05) and cardiac dynamics altered only by exposure to hypoxia. The cardiac interpulse interval was shortened (P < 0.001) similarly during hypoxia in both body positions. Vagally mediated high-frequency harmonic power (Ph) of HRV was decreased by hypoxia only in the supine position, while the fractal dimension, also linked to cardiac vagal control, was decreased in the sitting position (P < 0.05). However, low-frequency harmonic power (Pl) and the HRV indicator of sympathetic activity (Pl/Ph) were not altered by hypoxia in either position. These results suggest that, in humans, tachycardia induced by moderate IC hypoxaemia (arterial O2 saturation Sa,O2, 85%) was mediated by vagal withdrawal, irrespective of body position and resting autonomic balance, while associated changes in HRV were positionally dependent. [source] The effect of single oral low-dose losartan on posture-related sodium handling in post-TIPS ascites-free cirrhosis,HEPATOLOGY, Issue 3 2006George Therapondos Post-TIPS ascites-free patients with cirrhosis and previous refractory ascites demonstrate subtle sodium retention when challenged with a high sodium load. This is also observed in pre-ascitic patients with cirrhosis. This phenomenon is dependent on an intrarenal angiotensin II (ANG II) mechanism related to the assumption of erect posture. We investigated whether similar mechanisms were involved in post-TIPS ascites-free patients, by studying 10 patients with functioning TIPS and no ascites. We measured the effect of changing from supine to erect posture on sodium excretion at baseline and after single oral low dose losartan (7.5 mg) which has been shown to blunt proximal and distal tubular sodium reabsorption in pre-ascites. At baseline, the assumption of erect posture produced a reduction in sodium excretion (from 0.30 ± 0.06 to 0.13 ± 0.02 mmol/min, P = .05), which was mainly due to an increase in proximal tubular reabsorption of sodium (PTRNa) (69.7 ± 3.1% to 81.1 ± 1.8%, P = .003). The administration of losartan resulted in a blunting of PTRNa (supine 69.7 ± 3.1% to 63.9 ± 3.9%, P = .01 and erect 81.1 ± 1.8% to 73.8 ± 2.4%, P = .01), accompanied by an increased distal tubular reabsorption of sodium in both postures, with no overall improvement in sodium excretion on standing. In conclusion, post-TIPS ascites-free patients with cirrhosis exhibit erect posture-induced sodium retention. We speculate that (1) this effect is partly mediated by the effect of ANG II on PTRNa and (2) that the inability of low dose losartan to block the erect posture-induced sodium retention may be related to the erect posture-induced rise in aldosterone which is unmodified by losartan. (HEPATOLOGY 2006;44:640,649.) [source] The mechanism of improved sodium homeostasis of low-dose losartan in preascitic cirrhosisHEPATOLOGY, Issue 6 2002Florence Wong 200 Elizabeth St. Renal sodium retention on standing is one aspect of the abnormal renal sodium handling in preascitic, well-compensated patients with cirrhosis. Recently, it has been shown that low doses (7.5 mg) of the angiotensin II (Ang II) receptor antagonist, losartan, can reverse renal sodium retention on high, 200-mmol sodium/d diet in these patients and restore them to sodium balance. Therefore, the effect of 7.5 mg of losartan on sodium excretion, when changing from supine to erect posture for 2 hours, was examined in 10 well-compensated patients with cirrhosis and 9 age- and sex-matched controls on the same sodium diet, under strictly controlled metabolic conditions. In contrast to control subjects, in whom sodium excretion was unaffected, single 7.5-mg doses of losartan again restored the preascitic patients with cirrhosis to sodium balance. In addition, it blunted the fall in erect posture, induced renal sodium excretion by a reduction in proximal and distal tubular reabsorption of sodium. These changes occurred without any significant changes in blood volumes, systemic and renal hemodynamics, or glomerular filtration rate (GFR) and filtered sodium load compared with controls, and despite activation of the systemic renin-angiotensin-aldosterone system, which was still within normal levels. In conclusion, the beneficial natriuretic effects of low-dose losartan on erect posture , induced sodium retention in preascitic cirrhosis supports the suggestion that the pathophysiology of sodium retention in preascites is in part caused by an intrarenal tubular effect of Ang II in that posture. [source] Gravity is an important determinant of oxygenation during one-lung ventilationACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2010L. L. SZEGEDI Background: The role of gravity in the redistribution of pulmonary blood flow during one-lung ventilation (OLV) has been questioned recently. To address this controversial but clinically important issue, we used an experimental approach that allowed us to differentiate the effects of gravity from the effects of hypoxic pulmonary vasoconstriction (HPV) on arterial oxygenation during OLV in patients scheduled for thoracic surgery. Methods: Forty patients with chronic obstructive pulmonary disease scheduled for right lung tumour resection were randomized to undergo dependent (left) one-lung ventilation (D-OLV; n=20) or non-dependent (right) one-lung ventilation (ND-OLV; n=20) in the supine and left lateral positions. Partial pressure of arterial oxygen (PaO2) was measured as a surrogate for ventilation/perfusion matching. Patients were studied before surgery under closed chest conditions. Results: When compared with bilateral lung ventilation, both D-OLV and ND-OLV caused a significant and equal decrease in PaO2 in the supine position. However, D-OLV in the lateral position was associated with a higher PaO2 as compared with the supine position [274.2 (77.6) vs. 181.9 (68.3) mmHg, P<0.01, analysis of variance (ANOVA)]. In contrast, in patients undergoing ND-OLV, PaO2 was always lower in the lateral as compared with the supine position [105.3 (63.2) vs. 187 (63.1) mmHg, P<0.01, ANOVA]. Conclusion: The relative position of the ventilated vs. the non-ventilated lung markedly affects arterial oxygenation during OLV. These data suggest that gravity affects ventilation,perfusion matching independent of HPV. [source] Effects of restricted thoracic movement on the regional distribution of ventilationACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2010S. PULLETZ Background: Restricted thoracic movement is often encountered in patients, necessitating mechanical ventilation during surgery or intensive care treatment. High intraabdominal pressure, obesity or thorax rigidity and deformity reduce the chest distensibility and deteriorate the lung function. They render the selection of proper ventilator settings difficult and complicate the weaning process. Electrical impedance tomography (EIT) is currently being proposed as a bedside imaging method for monitoring regional lung ventilation. The objective of our study was to establish whether the effects of decreased chest compliance on regional lung ventilation can be determined by EIT. Methods: Ten healthy male volunteers were studied in our pilot study under three conditions: (1) unrestricted breathing and (2) restricted breathing by abdominal and (3) lower rib cage strapping. The subjects were followed during spontaneous tidal breathing in five postures (sitting, supine, prone, left and right side). EIT and spirometry data were acquired in each condition. Results: The distribution of ventilation in subjects with unrestricted breathing corresponded with the physiologically expected values. In the left and right lateral postures, abdominal and thoracic cage restrictions reduced the ventilation in the dependent lung areas; the non-dependent areas were unaffected. In the prone position, the ventilation of the dependent and non-dependent areas was reduced. The effects of strapping were least pronounced in the supine posture. Conclusions: We conclude that EIT is able to measure changes in the regional distribution of ventilation induced by restricted chest movement and has the potential for optimising artificial ventilation in patients with limited chest compliance of different origins. [source] Roman Period fetal skeletons from the East Cemetery (Kellis 2) of Kellis, EgyptINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2005M. W. Tocheri Abstract Much can be learned about the religious ideology and mortuary patterns as well as the demographic and health profiles of a population from archaeological human fetal skeletons. Fetal skeletons are rare, however, largely due to poor preservation and recovery, misidentification, or non-inclusion in general burial populations. We present an analysis of 82 fetal/perinatal skeletons recovered from Kellis 2, a Roman Period cemetery dated to the third and fourth centuries AD, located in the Dakhleh Oasis, Egypt. Most of the fetal remains were individually wrapped in linen and all were buried among the general cemetery population in a supine, east,west orientation with the head facing to the west. Gestational age estimates are calculated from diaphysis lengths using published regression and Bayesian methods. The overall similarity between the fetal age distributions calculated from the regression and Bayesian methods suggests that the correlation between diaphysis length and gestational age is typically strong enough to avoid the ,regression' problem of having the age structure of reference samples adversely affecting the age distribution of target samples. The inherent bias of the regression methods, however, is primarily reflected in the gestational age categories between 36 and 42 weeks corresponding with the expected increase in growth variation during the late third trimester. The results suggest that the fetal age distribution at Kellis 2 does not differ from the natural expected mortality distribution. Therefore, practices such as infanticide can be ruled out as having a significant effect on the observed mortality distribution. Moreover, the Kellis 2 sample is well represented in each gestational age category, suggesting that all premature stillbirths and neonatal deaths received similar burial rites. The age distribution of the Kellis 2 fetal remains suggests that emerging Christian concepts, such as the ,soul' and the ,afterlife', were being applied to everyone including fetuses of all gestational ages. Copyright © 2005 John Wiley & Sons, Ltd. [source] Laparoscopic nephropexy: Treatment outcome and quality of lifeINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2004YOSHIYUKI MATSUI Abstract Background:, The recent introduction of laparoscopic procedures has markedly altered urological surgery. Laparoscopic nephropexy has attracted the attention of urologists as a treatment for nephroptosis. Herein, we describe our experiences and quality-of-life outcome of laparoscopic nephropexy and discuss its indications and surgical techniques. Methods:, From May 1998 to February 2002, six female patients, ranging in age from 20 to 64 years (median age 39.8 years), with symptomatic nephroptosis underwent laparoscopic nephropexy. Mean preoperative downward kidney displacement was 2.25 vertebral bodies (range 2,2.5) and all affected kidneys were tilted at orthostasis. One patient underwent nephropexy through the transperitoneal approach and the remaining patients underwent nephropexy through the retroperitoneal approach. To evaluate surgical results, postoperative follow-up interview (pain visual analog scale and the short-form 36 (SF-36) health survey questionnaire) and objective examinations were performed. Results:, All procedures were accomplished without complication. Postoperative intravenous pyelography correctly confirmed fixed kidney in both supine and erect positions. All patients reported an improvement of symptoms approximately 1 month after nephropexy and no symptoms have recurred during the follow-up period (range 6.3,50.7 months). On the SF-36, two domains, including role limitations due to emotional problems (RE) and mental health (MH), exhibited significant improvement postoperatively (P = 0.0405 and P = 0.0351, respectively). Conclusions:, Laparoscopic, in particular retroperitoneoscopic, nephropexy yields excellent outcomes and greatly improves general health-related quality of life, particularly mental status, as a minimally invasive treatment for symptomatic nephroptosis. [source] Treatment of Vasodepressor Carotid Sinus Syndrome with Midodrine: A Randomized, Controlled Pilot StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2005Allan Moore MRCPI Objectives: To evaluate the efficacy of treatment of the vasodepressor form of carotid sinus hypersensitivity (carotid sinus syndrome (CSS)) with midodrine. Design: A prospective, double-blind, randomized, controlled trial of crossover design. Setting: A dedicated outpatient facility with access to tilt-table, digital arterial photoplethysmography, and 24-hour ambulatory blood pressure (BP) monitoring equipment. Participants: Ten older adults (4 male, 6 female, mean age 75, range 66,86 years) with a history of unexplained syncope who displayed an asymptomatic decrease in systolic BP (SBP) of more than 50 mmHg or a symptomatic decrease of more than 30 mmHg within 30 seconds of carotid sinus massage (CSM). Measurements: Symptom reproduction and BP and heart rate changes were evaluated after CSM in supine and semierect positions on the right and then left sides. These measurements were performed on the final day of placebo and active-treatment phases. Ambulatory 24-hour BP monitoring took place on the penultimate and final days of each treatment phase. Results: Eight patients were symptomatic after their initial CSM. The mean±standard deviation SBP decrease after initial CSM was 54±22 mmHg. Initial mean 24-hour ambulatory BP was 127/70±7/5 mmHg. Eight patients reported symptoms after CSM at the end of the placebo phase. The mean SBP decrease at the end of the placebo phase was 49±12 mmHg. The mean 24-hour ambulatory BP was 127/69±9/7 mmHg. One patient reported symptoms after CSM at the end of the active-treatment phase. The mean SBP decrease at the end of the active-treatment phase was 36±9 mmHg. The mean 24-hour ambulatory BP at the end of the treatment phase was 133/75±7/6 mmHg. The differences in symptom reporting and mean SBP decrease after CSM were both significant (P<.01 and P=.03, respectively). Conclusion: The results of this pilot study suggest that treatment of vasodepressor CSS with midodrine significantly reduced the rate of symptom reporting and attenuated SBP decreases after CSM but increased mean 24-hour ambulatory BP. [source] The intrinsic shape of the human lumbar spine in the supine, standing and sitting postures: characterization using an active shape modelJOURNAL OF ANATOMY, Issue 2 2009Judith R. Meakin Abstract The shape of the lumbar spine in the sagittal plane varies between individuals and as a result of postural changes but it is not known how the shape in different postures is related. Sagittal images of the lumbar spines of 24 male volunteers were acquired using a positional magnetic resonance scanner. The subjects were imaged lying supine, standing and sitting. An active shape model was used to characterize shape in terms of independent modes of variation. Two modes were identified that described the total (mode 1) and distribution (mode 2) of the curvature. The spinal shape was found to be intercorrelated between the three postures for both modes, suggesting that the lumbar spine has an element of shape that is partially maintained despite postural alterations. Mode 1 values indicated that the spine was straightest when standing and curviest when sitting. Mode 2 values indicated that the distribution in the curvature was most even when sitting and least even when lying supine. Systematic differences in the behaviour of the spine, when changing posture, were found that suggest that the shape of the spine may affect its biomechanics. [source] Relationship between stroke volume, cardiac output and filling of the heart during tiltACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2009M. BUNDGAARD-NIELSEN Background: Cardiac function curves are widely accepted to apply to humans but are not established for the entire range of filling of the heart that can be elicited during head-up (HUT) and head-down tilt (HDT), taken to represent minimal and maximal physiological filling of the heart, respectively. With the supine resting position as a reference, we assessed stroke volume (SV), cardiac output (CO) and filling of the heart during graded tilt to evaluate whether SV and CO are maintained during an assumed maximal physiological filling of the heart elicited by 90° HDT in healthy resting humans. Methods: In 26 subjects, central blood volume was manipulated with graded tilt from 60° HUT to 90° HDT. We measured SV, CO (Finometer®) and cardiac filling by echocardiography of the left ventricular end-diastolic volume (LVEDV; n=12). Results: From supine rest to 60° HUT, SV and CO decreased 23 ml [confidence intervals (CI): 16,30; P<0.001; 23%] and 0.9 l/min (0.4,1.4; P<0.0001; 14%), respectively, but neither SV nor CO changed during HDT up to 70°. However, during 90° HDT, SV decreased 12 ml (CI: 6,19; P<0.0001; 12%), with an increase of 21 ml (9,33; P=0.002; 16%) in LVEDV because HR increased 3 bpm and CO decreased 0.5 l/min (ns). Conclusion: This study confirmed that SV and CO are maximal in resting, supine, healthy humans and decrease during HUT. However, 90° HDT was associated with increased LVEDV and induced a reduction in SV. [source] Iloprost inhalation redistributes pulmonary perfusion and decreases arterial oxygenation in healthy volunteersACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2009D. RIMEIKA Background: Previous studies have shown that ventilation,perfusion matching is improved in the prone as compared with that in the supine position. Regional differences in the regulation of vascular tone may explain this. We have recently demonstrated higher production of nitric oxide in dorsal compared with ventral human lung tissue. The purpose of the present study was to investigate regional differences in actions by another vasoactive mediator, namely prostacyclin. The effects on gas exchange and regional pulmonary perfusion in different body positions were investigated at increased prostacyclin levels by inhalation of a synthetic prostacyclin analogue and decreased prostacyclin levels by unselective cyclooxygenase (COX) inhibition. Methods: In 19 volunteers, regional pulmonary perfusion in the prone and supine position was assessed by single photon emission computed tomography using 99mTc macro-aggregated albumin before and after inhalation of iloprost, a stable prostacyclin analogue, or an intravenous infusion of a non-selective COX inhibitor, diclofenac. In addition, gas distribution was assessed in seven subjects using 99mTc-labelled ultra-fine carbon particles before and after iloprost inhalation in the supine position. Results: Iloprost inhalation decreased arterial PaO2 in both prone (from 14.2±0.5 to 11.7±1.7 kPa, P<0.01) and supine (from 13.7±1.4 to 10.9±2.1 kPa, P<0.01) positions. Iloprost inhalation redistributed lung perfusion from non-dependent to dependent lung regions in both prone and supine positions, while ventilation in the supine position was distributed in the opposite direction. No significant effects of non-selective COX inhibition were found in this study. Conclusions: Iloprost inhalation decreases arterial oxygenation and results in a more gravity-dependent pulmonary perfusion in both supine and prone positions in healthy humans. [source] Acute Blood Pressure Changes After the Onset of Atrioventricular Nodal Reentrant Tachycardia: A Time-Course AnalysisJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2005MEHDI RAZAVI M.D. Introduction: We aimed to characterize blood pressure (BP) response at the beginning of atrioventricular nodal reentrant tachycardia (AVNRT) and its relationship to orthostatic challenge and variable atrioventricular interval. Methods and Results: In this prospective study of 17 consecutive patients with documented AVNRT, mean BP was analyzed in the supine and upright positions during sinus rhythm, AVNRT, and pacing with atrioventricular delay of 150 msec (AV150) and 0 msec (AV0). Mean BPs were compared at 3,5 seconds, 8,10 seconds, and 28,30 seconds after the onset of AVNRT or pacing. BP decreased immediately after AVNRT initiation, with gradual recovery during the first 30 seconds from 71.9 ± 16.5 mmHg to 86 ± 13.8 mmHg, P < 0.01. A similar pattern was observed during AV0, but not during AV150, pacing. While supine, mean BP decrease was more pronounced during AVNRT and AV0 pacing (,26.1% and ,32.1%, respectively) than during AV150 pacing (,8%, P = 0.02 and P = 0.07, respectively). This difference subsided 30 seconds after the onset of AVNRT or pacing. When upright, the mean BP time course was similar, but mean BP recovery during AVNRT was slower, and the difference between mean BP during AVNRT and AV150 persisted at 30 seconds. Conclusions: The initial mean BP decrease during AVNRT recovered gradually within 30 seconds. A short atrioventricular interval is associated with a greater mean BP decrease at the onset of tachycardia. These observations may explain clinical symptoms immediately after the onset of AVNRT. [source] Esophageal motility in patients with sliding hiatal hernia and reflux esophagitisJOURNAL OF DIGESTIVE DISEASES, Issue 2 2002Ping YE OBJECTIVE: To study the radiographic and esophageal motility changes that are characteristic of patients with both sliding hiatus hernia (HH) and reflux esophagitis. METHODS: Thirty patients were diagnosed with HH by using gastroscopy. These patients were divided into two groups according to the severity of their esophagitis: group HH1 (grades A and B, n= 18); group HH2 (grades C and D, n= 12). Sliding HH was confirmed by barium meal examination. Radiographic techniques were used to test for spasms and strictures, the coarseness of the mucosa, and to study the types of reflux and clearance. Esophageal pH (24-h), lower esophageal sphincter pressure and the frequency and amplitude of esophageal peristalsis during reflux were also studied. RESULTS: Radiography revealed that the mucosa was coarse in all cases. Eighty percent of patients had sucking reflux and 36.7% had passive clearance. The percentages of total, supine and upright acid exposure times were greater in patients with HH than those in the controls (P < 0.01), but the difference between the HH1 and HH2 groups was not significant. Lower esophageal sphincter resting pressure was less in the HH group than that in the control group (P < 0.05). However, there were no differences in the length of the sphincter among groups. During episodes of acid reflux, the frequency and amplitude of peristalsis, and the percentage of normal primary esophageal peristalsis were all lower in HH patients than in the controls, and the duration of peristalsis was increased relative to that of the controls (P < 0.05). CONCLUSIONS: Sucking reflux and passive clearance are very important in HH. Esophageal acid exposure time does not correlate with the severity of esophagitis. Lowered lower esophageal sphincter resting pressure, decreased frequency and amplitude, and increased duration of esophageal peristalsis during the episode of reflux may play an important role in the pathogenesis of sliding HH. [source] Comparison between intubation and the laryngeal mask airway in moderately obese adultsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009M. ZOREMBA Background: Obesity is a well-established risk factor for perioperative pulmonary complications. Anaesthetic drugs and the effect of obesity on respiratory mechanics are responsible for these pathophysiological changes, but tracheal intubation with muscle relaxation may also contribute. This study evaluates the influence of airway management, i.e. intubation vs. laryngeal mask airway (LMA), on postoperative lung volumes and arterial oxygen saturation in the early postoperative period. Methods: We prospectively studied 134 moderately obese patients (BMI 30) undergoing minor peripheral surgery. They were randomly assigned to orotracheal intubation or LMA during general anaesthesia with mechanical ventilation. Premedication, general anaesthesia and respiratory settings were standardized. While breathing air, we measured arterial oxygen saturation by pulse oximetry. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 0.5, 2 and 24 h after extubation, with the patient supine, in a 30° head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t -test analysis. Statistical significance was considered to be P<0.05. Results: Postoperative pulmonary mechanical function was significantly reduced in both groups compared with preoperative values. However, within the first 24 h, lung function tests and oxygen saturation were significantly better in the LMA group (P<0.001; ANOVA). Conclusions: In moderately obese patients undergoing minor surgery, use of the LMA may be preferable to orotracheal intubation with respect to postoperative saturation and lung function. [source] Proton and sodium MRI assessment of fluid level in calf tissueJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2006Chun S. Zuo PhD Abstract Purpose To investigate the feasibility of using 1H and 23Na MRI to detect fluid levels in the lower leg muscle. Materials and Methods Proton and sodium MRI was applied to detect body fluid levels in the lower leg muscles of 18 healthy young male subjects at 3T and 4T. The paradigms under investigation were a postural change from sitting upright to lying supine, and saline infusion. Results We found that the average proton MR signal in gastrocnemius and soleus muscles were reduced following the postural change by 3.5% ± 1.4% (P < 0.05) and rose following saline infusion by 3.7% ± 0.9% (P < 0.01). More dramatically, the sodium MR signal decreased by 7.1% ± 1.2% (P < 0.01) following the postural change and increased following saline infusion by 12% ± 3.8% (P < 0.05). The ratio of intra- to extracellular fluid levels was 1.6 ± 0.5 for the subjects based on the acquired proton and sodium data. Conclusion Our results indicate that proton and sodium MRI can be used to assess fluid levels in the lower extremities, and this technique may be applied to evaluate fluid retention. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Gravity-dependent signal gradients on MR images of the lung in supine and prone positions: A comparison with isogravitational signal variabilityJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2006Alexander A. Bankier MD Abstract Purpose To investigate the tendency of proton MR signal intensity (SI) gradients to be steeper in the supine than in the prone body position, and to quantify the relation between gravity-related and isogravitational changes of SI on proton MR images of the lung. Materials and Methods In eight healthy volunteers, MR images were obtained in the supine and prone positions using a multiple inversion recovery turbo spin-echo (TSE) sequence. The variation in SI along the gravity-dependent direction and within isogravitational planes was measured on a pixel-by-pixel basis. Ratios of slopes were calculated for comparisons among volunteers. Comparisons of ratios were made using Fisher's exact test. Isogravitational variability was compared with the mean SI, the signal-to-noise ratio (SNR), and the image noise. Results The average ratios of slopes showed that the overall SI gradient was steeper in the supine than the prone position, with a substantial difference in the supine/prone ratios between inspiration (1.21) and expiration (1.72). In both the supine and prone positions, gravity-dependent gradients were steeper in expiration than in inspiration (P = 0.001). The SI variability along the gravitational direction was larger than the isogravitational variability. The isogravitational variability in turn was larger than the image noise but smaller than the mean SI of the MR images. Conclusion Gravity-dependent gradients in proton MR SI are steeper in the supine than in the prone position. The magnitudes of these gradients were larger than the isogravitational signal variability, showing that MRI is sensitive to gravitationally induced effects. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Relationship between ease of swallowing and deglutition-related muscle activity in various posturesJOURNAL OF ORAL REHABILITATION, Issue 8 2010T. SAKUMA Summary, The purpose of this study was to investigate the relationship between the ease of swallowing and the deglutition-related muscle activity in various body and head postures by surface electromyography (EMG). Bipolar surface electrodes were placed on the right suprahyoid and infrahyoid muscles of nine healthy adults (19,28 years) while swallowing jelly. Ten postures per subject were examined: five body angulations (0° [supine], 30°, 60°, 90° [upright] and 120° from the horizontal) and two head positions (chin-up and chin-down). The duration and amplitude of suprahyoid and infrahyoid muscle activity were measured by an electromyograph, and the ease of swallowing was subjectively determined by using a rating scale (0 = difficult to swallow, 10 = easy to swallow). The group-average duration and amplitude of muscle activity and the group-average rating scales mostly showed insignificant changes with the body angulations independent of the head positions. Interestingly, the duration and amplitude of muscle activity during swallowing were negatively correlated with the rating scales, indicating that a shorter duration and smaller activity of muscle activity corresponds to easier swallowing. Consequently, the duration and amplitude of suprahyoid and infrahyoid muscle activity measured by surface EMG would be a useful indicator of the easy-to-swallow performance. [source] Influence of food properties and body posture on durations of swallowing-related muscle activitiesJOURNAL OF ORAL REHABILITATION, Issue 9 2008D. INAGAKI Abstract, The purpose of this study was to determine (i) whether or not textural properties of foods and body positions affect the durations of anterior tongue and suprahyoid muscle activities during swallowing, and (ii) if such changes occur, is the ,pre-peak' or the ,post-peak' duration of integrated muscle activity responsible. We used two test foods with different proprieties of hardness and adhesiveness. We recorded electromyograms (EMGs) from the anterior tongue and suprahyoid muscles as well as the laryngeal movement associated with swallowing in normal subjects (six men and three women; 21,30-years old). The subjects swallowed the test foods in four randomly set postures: upright, two inclined (60 ° and 30 ° to horizontal), and supine. None of the measured durations for the anterior tongue and suprahyoid EMGs were different among the four positions during swallowing of either food. The ,total' duration, from the start to the end of the integrated EMG, of anterior tongue activity was significantly (P < 0·001, anova) longer during the swallowing of the tougher and more adhesive food than during swallowing of the other food, but the ,total' duration of suprahyoid activity was unchanged. The ,post-peak' duration of anterior tongue activity, which stretched from the peak to the end of the integrated EMG, was also significantly longer (P < 0·001, anova) during swallowing of the tougher and more adhesive food. The results indicate that tougher and more adhesive foods prolong the duration, especially the ,post-peak' duration, of anterior tongue activity during swallowing in the upright, inclined and supine positions. [source] Body posture during sleep and disc displacement in the temporomandibular joint: a pilot studyJOURNAL OF ORAL REHABILITATION, Issue 2 2005H. HIBI summary, ,Many possible factors associated with internal derangement of the temporomandibular joint (TMJ) have been discussed, but the causal factors remain unproven. The present study aimed to investigate habitual body posture during sleep (HBP) of patients with anterior disc displacement (ADD) in the TMJ. The sample comprised 87 patients (12 males, 75 females) aged 13,68 years (mean 25 years) and diagnosed by magnetic resonance imaging as having unilateral or bilateral ADD in the TMJ. The HBPs were classified into five categories: supine, prone, right lateral, left lateral, and no-dominant positions. Of the 50 patients with the unilateral ADD, 33 (66%) had the ipsilateral HBP to the affected joint while none (0%) had the contralateral HBP. This contrast showed that the HBP was a possible contributing factor to the ADD. It was suggested that HBP allows the ipsilateral condyle to displace posteriorly and this posterior position causes relative ADD. [source] Role of mastication and swallowing in the control of autonomic nervous activity for heart rate in different posturesJOURNAL OF ORAL REHABILITATION, Issue 12 2003E. Nitta summary, Mastication and swallowing increase the heart rate, and posture change and respiration also modulate the heart rate. To clarify the role of mastication and swallowing in the modulation of the autonomic nervous activity, we investigated how they interact with modulation of the heart rate by changing body positions and respiration in young healthy subjects. R,R intervals of electrocardiogram at rest were significantly changed with different body positions, compared with supine and standing. A net shortening by mastication of a chewing gum base was similar in various postures. Respiration induced a periodic change in the R,R intervals, depending on the body postures, but mastication did not markedly change them in each posture. Dry swallowing at rest and spontaneous swallowing during the mastication in the sitting position induced a similar transient shortening and suppressed the respiration-induced changes after the swallowing. The net transient shortening by dry swallowing at rest was similar in the different postures. These results suggest that signals from mastication and swallowing are summated with those from body positions and respiration for shortening the R,R intervals and that signals from swallowing suppress the respiration-induced periodic changes. [source] Early Detection Of Diminished Baroreflex Sensitivity In Diabetic Patients Without Evidence Of Cardiovascular Autonomic NeuropathyJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2000D Ziegler Diabetic cardiovascular autonomic neuropathy (CAN) carries an increased risk of mortality. Decreased baroreflex sensitivity (BRS) has been identified as a predictor of increased mortality following myocardial infarction. We evaluated spontaneous BRS in 39 healthy control subjects (C: age (mean ± SEM): 41.5 ± 1.9 years) and 116 diabetic patients (64% Type 1, 36% Type 2; age: 45.8 ± 1.4 years; diabetes duration: 16.9 ± 1.0 years; HbA1c: 9.2 ± 0.2%) using cross-spectral analysis between systolic blood pressure and heart rate in the low-frequency (LF) and high-frequency (HF) bands as well as time domain (sequence) analysis in the supine and standing positions over 10 min. According to previously suggested definitions based on autonomic function tests (AFTs), 36 patients had definite CAN (CAN+: 3 of 7 indices abnormal), 13 had borderline CAN (CAN[+]: 2 of 7 indices abnormal), and 64 had no evidence of CAN (CAN,: 1 of 7 indices abnormal). Maximum gain in cross-spectral LF band (standing) was significantly reduced in CAN, as compared with C (5.2 ± 0.4 vs. 7.2 ± 0.8 ms/mmHg, p < 0.05). Moreover, maximum gain in cross-spectral HF band was significantly lower in CAN, than in C (supine: 12.0 ± 1.2 vs. 17.9 ± 2.5 ms/mmHg, p < 0.05; standing: 4.9 ± 0.5 vs. 8.7 ± 1.0 ms/mmHg, p < 0.05). The slope of the regression line between defined increases or reductions in systolic blood pressure and R-R intervals was significantly reduced in CAN, compared to C (supine: 10.6 ± 0.7 vs. 14.2 ± 1.6 ms/mmHg, p < 0.05; standing: 5.6 ± 0.4 vs. 8.1 ± 0.7 ms/mmHg, p < 0.05). Similar differences were obtained when comparing the CAN, and CAN[+] groups, the latter showing significantly reduced BRS by both techniques (p < 0.05). In contrast, no such differences were noted when comparing the CAN[+] and CAN+ groups. In conclusion, reduced spontaneous baroreflex sensitivity is an early marker of autonomic dysfunction at a stage when autonomic function tests do not yet indicate the presence of CAN, while cases with borderline CAN show a degree of BRS abnormality that is comparable to the level seen in definite CAN. Prospective studies are needed to evaluate whether reduced BRS is a predictor of mortality in diabetic patients. [source] Effect of hiatal hernia on proximal oesophageal acid clearance in gastro-oesophageal reflux disease patientsALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2006S. EMERENZIANI Summary Background Proximal acid reflux is common in gastro-oesophageal reflux disease and is a determinant of symptoms. Patients with hiatal hernia complain of more symptoms than those without and are less responsive to proton-pump inhibitors. Aim To evaluate the role of hiatal hernia on spatiotemporal characteristics of acid reflux. Methods Thirty seven consecutive gastro-oesophageal reflux disease patients underwent endoscopy, videofluoroscopy, manometry and multichannel 24-h pH test. Data were compared with those of 15 asymptomatic controls. Multivariate linear regression was used for statistical analysis. Results At videofluoroscopy, hiatal hernia was found in 16 of 37 patients. The mean size of hiatal hernia was 3.4 cm. Patients showed significantly prolonged acid clearance time, both at proximal and distal oesophagus, compared with controls. Hiatal hernia patients showed a significantly delayed acid clearance, along the oesophageal body, compared with non-hiatal hernia patients. The prolonged acid exposure was maintained during upright and supine position. The presence of hiatal hernia significantly predicted acid clearance delay in the distal and proximal oesophagus [at 10 cm below upper oesophageal sphincter: , + 2.5 min (95% confidence interval: 0.4,4.5); P < 0.02]. Conclusions The presence of hiatal hernia is a strong predictor of more prolonged proximal oesophageal acid exposure and clearance. Hiatal hernia is likely to play a role in the pathophysiology of gastro-oesophageal reflux disease symptoms, and should be taken into greater consideration in the treatment strategies of the disease. [source] Reverse sensory geste in cervical dystonia,MOVEMENT DISORDERS, Issue 2 2009Friedrich Asmus MD Abstract Sensory gestes (SG) are a pathognomonic sign of dystonia, which can be detected in up to two thirds of patients with cervical dystonia (CD). They reduce dystonia severity markedly but transiently. We report a patient whose CD substantially worsened with sensory input to the back of the head and neck in different body postures, a phenomomen recently termed "reverse" sensory geste (rSG) in craniocervical dystonia. In a cohort of CD outpatients, screening for "reverse" effects of SG on dystonia yielded a prevalence of 12.8% (n = 6/47). The most frequent rSG pattern was increased dystonic activity in a supine, resting position while trying to fall asleep. The response to rSG persisted throughout the course of the disease arguing for an impairment of central integration of neck proprioception. Assessment of rSG should be included in the routine examination of CD patients, since BTX treatment may have to beadjusted accordingly to be efficacious. © 2008 Movement Disorder Society [source] | ||||||||||||||||||||||||||||||||||