Esophageal solid bolus transit: studies using concurrent videofluoroscopy and manometry.

Understanding respiratory motions of liver and its surrogate organs is crucial for precise dose delivery in liver cancer radiotherapy. Although these motions have been studied for respiratory motion management in the supine posture, few studies have quantified them and evaluated their correlations in the upright posture. This study quantified the respiratory motions of liver and surrogate organs and evaluated the correlations between the liver motions and surrogate signals for respiratory motion monitoring in both the supine and upright postures. 4D dynamic volume computed tomography (CT) images were acquired from 13 asymptomatic volunteers in both supine and upright postures while free breathing. The 4D liver motions were calculated by performing deformable image registration. Subsequently, superior-inferior (SI) motion at the right diaphragm apex and anterior-posterior (AP) motion at the abdominal skin surface were obtained as surrogate signals from the 4D CT images. The average displacements and maximum magnitudes of liver motions and surrogate signals were compared between the postures. Moreover, the correlations between the liver motions and surrogate signals were evaluated based on correlation models. The average liver displacements from the end-exhalation along the SI, AP, and left-right directions were -6.1, 2.1, and -0.4 mm in the supine posture and -4.6, 2.5, and 0.1 mm in the upright posture, respectively. The maximum motion range along the SI direction significantly decreased from 16.3 ± 6.6 mm in the supine posture to 11.0 ± 2.7 mm in the upright posture. Similar to the supine posture, the correlation models also reproduced the liver motions with high fitting accuracy in the upright posture. Compared to the conventional supine posture, the liver SI motion became smaller in the upright posture while keeping evident correlations with the surrogate signals, which suggests the upright posture will allow precise dose delivery with reduced internal target margins.

There are a number of potential physical advantages to performing orotracheal intubation in an upright position. The objective of this study was to measure the success of intubation of a simulated patient in an upright versus supine position by novice intubators after brief training. This was a cross-over design study in which learners (medical students, physician assistant students, and paramedic students) intubated mannequins in both a supine (head of the bed at 0°) and upright (head of bed elevated at 45°) position. The primary outcome of interest was successful intubation of the trachea. Secondary outcomes included log time to intubation, Cormack-Lehane view obtained, Percent of Glottic Opening score, provider assessment of difficulty, and overall provider satisfaction with the position. There were a total of 126 participants: 34 medical students, 84 physician assistant students, and 8 paramedic students. Successful tracheal intubation was achieved in 114 supine attempts (90.5%) and 123 upright attempts (97.6%; P=0.283). Upright positioning was associated with significantly faster log time to intubation, higher likelihood of achieving Grade I Cormack-Lehane view, higher Percent of Glottic Opening score, lower perceived difficulty, and higher provider satisfaction. A subset of 74 participants had no previous intubation training or experience. For these providers, there was a non-significant trend toward improved intubation success with upright positioning vs supine positioning (98.6% vs. 87.8%, P=0.283). For all secondary outcomes in this group, upright positioning significantly outperformed supine positioning.

The correlation between the anatomical cardiac and electrocardiographic axes has been discussed for several years. Using upright computed tomography, this study aimed to reveal the relationship between the anatomical cardiac and electrocardiographic axes in both the supine and upright positions. Upright CT and standard supine CT were performed for healthy volunteers, following electrocardiography in both upright and supine position. On CT images, the coordinates of apex, the center of aortic valve (AV) and mitral valve (MV) were recorded, and the vectors and angles were calculated. Subcutaneous and visceral fat volume were semi-automatically calculated in a workstation. From a total 190 volunteers, 41 males were performed electrocardiography and included for this study. The QRS and anatomical axes (AV-apex and MV-apex axis) were significantly correlated in both supine and upright positions, while the angle of the AV-apex to Z axis was the most correlated (supine: r = − 0.54, p = 0.0002, upright: r = − 0.47, p = 0.0020). The anatomical axis moved in the dorsal and caudal directions from the supine to upright position. Multiple regression analysis revealed that the anatomical axis from the AV-apex to the Z-axis was determined according to age, body height, subcutaneous and visceral fat volumes.

The function of the autonomic nervous system in patients with vertigo was examined, and several parameters of the RR interval were analyzed quantitatively in the supine and upright positions. Fifty-five patients with vertigo associated with autonomic nerve dysfunction were examined, and were analyzed by computer. Patients with normal autonomic function (Group 1: n=26) and those with autonomic dysfunction (Group 2: n=25) were compared statistically. Group 2 contained four subgroups: Group 2a: 15 patients with sympathetic hyperfunction; Group 2b: 9 patients with sympathetic hypofunction; Group 2c: 2 patients with parasympathetic hyperfunction; and Group 2d: 6 patients with parasympathetic hypofunction). Six patients had double dysfunctions.The parameters examined were:1. Heart Rate (HR).2. Coefficient of variation of RR interval (RRcv).3. Relation between RRcv and age.4. Power spectrum of RR interval.HR and RRcv were recorded in the supine and upright positions. RR intervals of 20 seconds were computed with FFT, and 2 major components (low frequency; 0.1Hz (P1): high frequency; 0.3Hz (P2)) of the power spectrum were analyzed. HR of Group 2a was significantly higher than that of Group 1 in both the supine and upright positions. RRcv of Group 2b was lower than that of Group 1. RRcv of Group 2c was reduced in the upright position. RRcv of Group 2d was lower than that of Group 1 and tended to rise in the upright position. RRcv of Group 1 in the upright position was related to age (r=-0.62), but that of Group 2 showed no significant relation. The power spectrum of Group 1 showed a dominant P2 in the supine position and a dominant P1 in the upright position, but the power spectrum of Group 2a revealed a dominant P1 in both the supine and upright positions and that of Group 2b showed no marked P1 and P2 components.

Anesthetic Efficacy of Supine and Upright Positions for the Inferior Alveolar Nerve Block: A Prospective, Randomized Study

GullbringB., A. Holmgren, T. Sjöstrandand T. Strandell.The effect of blood volume variations on the pulse rate in supim and upright positions and during txercice.The effect of bleeding of about 10 per cent of the blood volume and reinfusion of this quantity of blood seven days later was studied in six male subjects. The study includes determination of the pulse rate at rest in supine and upright positions and during exercise on a bicycle ergometer. The physical working capacity (PWC170) was computed from the pulse rates during work. The pulse rate in upright position and during exercise increases and PWC170decreases immediately after the bleeding. During the next few days PWC170increases and the pulse rate in upright position and during exercise decreases, while the pulse rate in supine position appeared to increase. On the sixth day PWC170was found to be higher and the pulse rate in supine and upright positions and during exercise to be lower than before the bleeding. Reinfusion of the blood seemed to produce a further moderate increase in PWC170. The decrease in PWC170after the bleeding corresponded, on the whole, to the average relation in different individuals between PWC170and the total amount of hemoglobin. The respiratory rate during exercise increased after the bleeding and also showed the same tendency as the pulse rate did during exercise and in upright position during the next few days.

Systematic biases in the tactile perception of the subjective vertical in patients with unilateral neglect and the influence of upright vs. supine posture

The study aimed to investigate whether pelvic tilt (PT) angles differ between the supine and upright position in symptom-free young adults. Additionally, the concurrent validity of the measurement system was tested on a pelvis phantom against a digital inclinometer. A new smartphone-based navigated ultrasound system was used to perform the measurements. The sample consisted of 12 symptom-free young adults. A multivariate regression model was used to analyze the data. The subjects’ pelvis in supine position was significantly more tilted anteriorly (mean PT = −7.3°, 95% C.I.: −10.6 to −3.9) than in upright position (mean PT = 0.8°, 95% C.I.: −2.5 to 4.1) (mean. diff. 8.1°; p < 0.001). Rater and trial order had no significant effects on the measured PT angles (p = 0.5). The accuracy of the system when measuring PT angles on the pelvis phantom was 0.3° (0.1° to 0.7°) and 0.2° (−0.09° to 0.6°) for the supine and upright positions respectively. Pelvic tilt angles differed significantly between the supine and the upright position in symptom-free young adults. Concurrent validity showed no differences for measurements in the upright position and small (under 0.4°) significant differences for measurements in the supine position.

Kinesthetic estimation of the main orientations from the upright and supine positions

Mechanical compliance of a compartment is defined by the change in its volume with respect to a change in the inside pressure. The compliance of the spinal canal regulates the intracranial pressure (ICP) under postural changes. Understanding how gravity affects ICP is beneficial for poorly understood cerebrospinal fluid (CSF)-related disorders. The aim of this study was to evaluate postural effects on cranial hemo- and hydrodynamics. This was a prospective study, which included 10 healthy volunteers (three males, seven females, mean ± standard deviation age: 29 ± 7 years). Cine gradient-echo phase-contrast sequence acquired at 0.5T, "GE double-doughnut" scanner was used. Spinal contribution to overall craniospinal compliance (CSC), craniospinal CSF stroke volume (SV), magnetic resonance (MR)-derived ICP (MR-ICP), and total cerebral blood flow (TCBF) were measured in supine and upright postures using automated blood and CSF flows quantification. Statistical tests performed were two-sided Student's t-test, Cohen's d, and Pearson correlation coefficient. MR-ICP and the craniospinal CSF SV were significantly correlated with the spinal contribution to the overall CSC (r=0.83, p < 0.05) and (r=0.62, p < 0.05), respectively. Cranial contribution to CSC increased from 44.5% ± 16% in supine to 74.9% ± 8.4% in upright posture. The average MR-ICP dropped from 9.9 ± 3.4 mmHg in supine to -3.5 ± 1.5 mmHg. The CSF SV was over 2.5 times higher in the supine position (0.55 ± 0.14 ml) than in the upright position (0.21 ± 0.13 ml). In contrast, TCBF was slightly higher in the supine posture (822 ± 152 ml/min) than in the upright posture (761 ± 139 ml/min), although not statistically significant (p=0.16). The spinal-canal compliance contribution to CSC is larger than the cranial contribution in the supine posture and smaller in the upright posture. Thereby, the spinal canal plays a role in modulating ICP upon postural changes. The lower pressure craniospinal CSF system was more affected by postural changes than the higher-pressure cerebral vascular system. Craniospinal hydrodynamics is affected by gravity and is likely to be altered by its absence in space. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 2.

Combined inhalation of nitric oxide and oxygen in patients with moderate to severe COPD: effect on blood gases

Background: Patients describe that body posture may affect their abdominal bloating, distension, and flatulence, but whether changes in position have objectively demonstrable effects, either beneficial or deleterious, has not been...

Carbonated water has long been a popular beverage, but its impact on esophageal motility remains unclear. This study aimed to evaluate the effect of carbonated water using high-resolution esophageal manometry (HRM). A standard HRM protocol, incorporating measurements in both supine and upright positions per the updated Chicago Classification v4.0, along with additional carbonated water swallows, was performed in our motility laboratory. Ineffective esophageal motility (IEM) was diagnosed based on > 70% ineffective swallows or ≥ 50% failed peristalsis in the supine position and categorized as "Supine IEM (SI)". Patients who met the IEM diagnostic criteria in the upright position but not in the supine position were classified as "Upright Ineffective (UI)" for further comparison. A total of 62 patients were found to have ineffective motility, with 30 diagnosed with IEM (SI group) and 32 categorized as UI. Compared with the standard water swallows, carbonated water increased the median DCI in the upright position (130 vs. 208 mmHg·cm·s, p < 0.001). It also reduced the proportion of failed peristalsis (85% vs. 65%, p < 0.01) and ineffective swallows (94% vs. 69%, p < 0.001) during upright swallows. The number of ineffective motility cases was reduced from 30 to 26 in the SI group, indicating a 13% improvement, and from 32 to 22 in the UI group, representing a 31% improvement (p < 0.01). Carbonated water significantly improves esophageal motility, particularly in the upright position. This effect is more pronounced in patients with upright ineffective motility.

To evaluate the potential relationship between scrotal ultrasound findings and abnormal semen analysis. Eighty-seven patients with varicoceles underwent semen analysis and scrotal sonography. On ultrasound, estimated testes volume and the largest pampiniform vein diameters on the affected side at rest and with Valsalva manoeuvre in both the supine and upright positions were examined. In addition, the differences between the largest venous diameters at rest and during the Valsalva manoeuvre in each position (supine and upright) and also the differences between the largest venous diameter in the supine position and the upright position in each condition (at rest and during the Valsalva manoeuvre) were calculated. The relationship between various ultrasound parameters and impaired semen analysis was evaluated using receiver operating characteristic curves. Seventy-one patients had spermatogenesis impairment, and the remaining 16 had normal semen analysis. The difference in the mean spermatic vein diameter at rest between the supine and upright positions (cut-off point, 0.25 mm) had the highest diagnostic accuracy in differentiating the patients with abnormal sperm analysis from those with normal spermatogenesis with an area under the curve of 0.86. Real-time scrotal ultrasound can be helpful in predicting abnormal sperm analysis in patients with varicoceles. Scrotal ultrasound is a non-invasive method to evaluate spermatic veins in varicoceles. Ultrasound can evaluate venous dimension change at rest after upright position (ΔD(R) ). ΔD( R) > 2.5 mm distinguishes patients with abnormal semen analysis. ΔD( R) has the most accuracy in predicting abnormal spermatogenesis. Ultrasound findings improve differentiation between patients with abnormal and normal spermatogeneses.

Understanding the degree of facial mobility upon postural changes is of great clinical relevance especially if facial assessment, facial measurements and/or facial markings are done in an upright position, but facial procedures are performed in a supine position. The objective of this study is to investigate regional facial skin displacement and facial volume changes in individuals between upright and supine positions. This multi-center study analyzed a total of 175 study participants with a mean age of 35.0 (10.2) years and a mean body mass index of 24.71 (3.5) kg/m2. 3D surface scanning technology with automated registration and alignment was utilized, and multivariate analyses were performed with adjustment for age, gender, body mass index, facial skin sagging and laxity. The medial face displaced less than the lateral face in both cranial (0.88 mm) and in lateral (0.76 mm) directions, and the lower face displaced more than the middle face in both cranial (1.17 mm) and lateral directions (1.37 mm). Additionally, the medial face lost, on average, 3.00cc whereas the lateral face increased by 5.86cc in volume; the middle face increased by 2.95cc, whereas the lower face decreased by 0.98cc in volume. All p < 0.001. Practitioners should be mindful that there is a statistically significant change in facial soft tissues between the upright and supine positions and that the magnitude of the change does not necessarily reflect on the aging process alone but is a multi-factorial process which should be individualized for each patient's needs. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .