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Results for “Supine Position”

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At least 379 records · Page 21Linked to original sources

PubMed1994

Anterior rectocele: assessment with radiographic defecography, dynamic magnetic resonance imaging, and physical examination.

PURPOSE: The aim of this study was to devise a measuring method for an anterior rectocele on standardized defecographies and magnetic resonance images (MRI) to quantify anterior rectocele and to test whether this could substantiate clinical decision making for operative treatment for anterior rectocele. METHODS: Quantitative analysis by the measuring method as proposed was compared with qualitative scores on defecographies and MRI from the same patients. Thirty-eight patients with symptoms compatible with an anterior rectocele were subjected to physical examination in the left decubitis position and supine position and to defecography. Findings on defecography were compared with findings on physical examination. Thirteen patients were examined before and after surgical correction of the anterior rectocele for a total of 51 qualitative and quantitative examinations. The group of operated patients was analyzed for treatment results. Nineteen controls were included. RESULTS: Sixty-six radiographs of 33 defecographies were qualified in three grading classes and quantified with the proposed method by two observers. The mean measured value of the anterior rectocele in the three subjective grading classes is significantly different (P < 0.001). Anterior rectoceles qualified as severe had a measured value of 20 mm or more in 96 percent of the radiographs. Lower gradings were never > 20 mm. On MRI severe anterior rectoceles were not scored and measured values did not correlate with qualitative scores. When findings on physical examination were compared with defecographic measurement, the coefficient of correlation (r) between the radiologic assessment and clinical examination in the left decubitis position is r = 0.87, for the examination in the supine position, r = 0.77. All 15 cases scored as severe anterior rectocele in the left decubitis position had a measured anterior rectocele of > or = 20 mm. In the 13 cases that received surgery, there was a significant reduction of the anterior rectocele (P < 0.001) and clinical improvement. Patients with small or moderate anterior rectocele on physical examination with a size > or = 20 mm on defecography were cured by surgical correction. None of the controls had an anterior rectocele on physical examination or an anterior rectocele > or = 20 mm on defecography. CONCLUSIONS: An anterior rectocele with a size of 20 mm or more corresponds with a qualitative score of "severe" on radiographic defecography. Physical examination for anterior rectocele in the left decubitis position corresponds best with quantitative radiographic assessment and anterior rectocele with a size > or = 20 mm on defecography is pathologic. Patients with complaints compatible with anterior rectocele can be assessed in objective and quantitative terms by radiography and can be successfully surgically treated, even if at physical examination the anterior rectocele is not classified as large, provided that dynamic defecography shows an anterior rectocele of > or = 20 mm. The potential of dynamic MRI with regard to anterior rectoceles presently seems absent.

Adult↗

PubMed1987

[Significance of the examination position in urodynamic assessment of female urinary incontinence].

The present paper describes a test center which permits urodynamics tests with the patient in various positions, such as lithotomy position (A), supine position with outstretched legs (B) and, by continuously raising the patient, upright position (C). The results of a comparative investigation show the influence of these different examination positions on urodynamic parameters, in particular the functional length of the urethra and maximum urethra closing pressure at rest. Urodynamic tests on 40 patients with urinary incontinence showed that there is a significant increase in the functional length of the urethra when the patient is in lithotomy position (A) as compared to lying with outstretched legs (B), and that it is once again significantly reduced when the patient is raised to upright position. Maximum urethra closing pressure at rest drops significantly when the patient is repositioned from lithotomy (A) to supine (B) position, and once again rises significantly when she is raised to the upright (C) as compared to the supine (B) position. In the light of the changes described, which cause major changes in the form of the urethra pressure profile, it makes sense to perform urodynamic measurements in at least two different positions. The authors recommend the supine position with outstretched legs (B), as it appears more physiological than the lithotomy position (A), and measurement in the upright position (C). The importance of positioning with regard to the diagnostic information value in determining the cause of urinary incontinence is discussed.

Adult↗

PubMed1993

Faster O2 uptake kinetics at onset of supine exercise with than without lower body negative pressure.

The kinetics of oxygen uptake (VO2) were observed at the onset of submaximal cycling exercise in seven men and one woman [mean age 22.6 +/- 0.9 (SE) yr] in the upright and supine positions and the supine position with -40 mmHg lower body negative pressure (LBNP). There was no significant difference for peak VO2 and ventilatory threshold between the supine (3,081 +/- 133 and 1,954 +/- 138 ml/min, respectively) and the supine + LBNP positions (3,062 +/- 152 and 1,973 +/- 122 ml/min); however, both were reduced compared with upright exercise (3,483 +/- 200 and 2,353 +/- 125 ml/min). Kinetic analysis applied to six repetitions by each subject indicated a slowing from a mean total lag time (time required to achieve 63% of the difference in VO2 between baseline and new steady state) of 36.3 +/- 2.7 s in upright exercise to 44.1 +/- 3.5 s in the supine position. However, total lag time for the supine + LBNP position (36.0 +/- 2.8 s) did not differ from upright exercise but was significantly faster than supine exercise. These data have been interpreted in support of an O2 transport limitation to VO2 kinetics at the onset of supine exercise that is countered by LBNP, likely through a more rapid increase in perfusion to the exercising muscle at these submaximal work rates.

Adult↗

PubMed1991

[Effects of respiratory physical therapy and nasopharyngeal suction on gastroesophageal reflux in infants less than a year of age, with or without abnormal reflux].

The purpose of this study was to analyse the effects on gastro-oesophageal reflux (GOR) of the different manipulations used during pulmonary physical therapy (nasal suctions, oropharyngeal suctions, acceleration of expiratory flow). 115 children less than 1 year old, were divided into two groups according to the results of oesophageal pH monitoring: 44 with and 61 without pathological GOR. Nasal suctions did not significantly increase GOR in children without pathological GOR. Oropharyngeal suctions increased GOR significantly more than nasal suctions (*p = 0.031). The technique of acceleration of expiratory flow, used in 35 degrees verticalized position and supine position, increased the index of reflux and the time with oesophageal pH below 4 in children with pathological GOR. However it did not increase reflux in normal children. The index of induced reflux in the whole population was increased in the horizontal position (4.81 +/- 0.88 reflux/hour) as compared with 35 degrees verticalized (2.92 +/- 0.79 reflux/hour). These oesophageal pH measurements confirm the clinical observations often made during physical therapy (vomiting, regurgitations, reflex cough). This statistical study suggests that one should take into account the adverse factor of GOR secondary to pulmonary physical therapy. It seems better to use nasal rather than oropharyngeal suctions and also to use the acceleration of expiratory flow technique in the 35 degrees verticalized rather than in the supine position, even more so if a pathological reflux does exist.

Gastroesophageal Reflux↗

PubMed1985

The Grosse-Kempf interlocking nail: technique of femoral and tibial fractures.

An anatomical reduction is required on both the lateral and AP view. In our hands this is easiest obtained and maintained with the patient in the supine position. The supine position facilitates better anesthesia care in the multiply injured patient and aids in movement of the image intensifer during the procedure. Each step should be carefully followed and the horizontal screw placement is possible only when the image of the holes is perfectly round. When the previously mentioned conditions and steps are followed, a successful locking nail insertion can be achieved.

Bone Nails↗

PubMed1999

Internal organ motion in prostate cancer patients treated in prone and supine treatment position.

BACKGROUND AND PURPOSE: To compare supine and prone treatment positions for prostate cancer patients with respect to internal prostate motion and the required treatment planning margins. MATERIALS AND METHODS: Fifteen patients were treated in supine and fifteen in prone position. For each patient, a planning computed tomography (CT) scan was used for treatment planning. Three repeat CT scans were made in weeks 2, 4, and 6 of the radiotherapy treatment. Only for the planning CT scan, laxation was used to minimise the rectal content. For all patients, the clinical target volume (CTV) consisted of prostate and seminal vesicles. Variations in the position of the CTV relative to the bony anatomy in the four CT scans of each patient were assessed using 3D chamfer matching. The overall variations were separated into variations in the mean CTV position per patient (i.e. the systematic component) and the average 'day-to-day' variation (i.e. the random component). Required planning margins to account for the systematic and random variations in internal organ position and patient set-up were estimated retrospectively using coverage probability matrices. RESULTS: The observed overall variation in the internal CTV position was larger for the patients treated in supine position. For the supine and prone treatment positions, the random components of the variation along the anterior-posterior axis (i.e. towards the rectum) were 2.4 and 1.5 mm (I standard deviation (1 SD)), respectively; the random rotations around the left-right axis were 3.0 and 2.9 degrees (1 SD). The systematic components of these motions (1 SD) were larger: 2.6 and 3.3 mm, and 3.7 and 5.6 degrees, respectively. The set-up variations were similar for both treatment positions. Despite the smaller overall variations in CTV position for the patients in prone position, the required planning margin is equal for both groups (about 1 cm except for 0.5 cm in lateral direction) due to the larger impact of the systematic variations. However, significant time trends cause a systematic ventral-superior shift of the CTV in supine position only. CONCLUSIONS: For internal prostate movement, it is important to distinguish systematic from random variations. Compared to patients in supine position, patients in prone position had smaller random but somewhat larger systematic variations in the most important coordinates of the internal CTV position. The estimated planning margins to account for the geometrical uncertainties were therefore similar for the two treatment positions.

Algorithms↗

PubMed2006

The effect of the lateral decubitus position on the intraocular pressure in anesthetized patients undergoing lung surgery.

BACKGROUND: Changing the body position alters the intraocular pressure (IOP). The aim of this study was to investigate the alteration in IOP of the eyes after a positional change from a supine position to a lateral decubitus position in anesthetized patients, in order to detect differences in IOP between the two eyes, possibly due to a gravity effect, in the lateral decubitus position. METHODS: IOP was measured in 20 patients undergoing lung surgery. IOP in both eyes was recorded prior to anesthesia in the supine position (baseline), after anesthetic induction but before tracheal intubation in the supine position, at the end of central venous catheterization in the Trendelenburg position, 5 min after a positional change to the lateral decubitus position, once every 30 min until the end of surgery in the lateral decubitus position, and 5 min after changing back to the supine position. RESULTS: The median IOP (16.3 mmHg; 25-75% percentile, 13-20 mmHg) in the dependent eye 5 min after changing to the lateral decubitus position increased significantly from the baseline median IOP (14.3 mmHg; 13-17.3 mmHg; P < 0.05). The increase in median IOP in the dependent eye persisted until the end of surgery in the lateral decubitus position (19 mmHg; 16.5-22.3 mmHg; P < 0.01 vs. baseline). The median IOP in the dependent eye was significantly higher than that in the non-dependent eye when anesthetized patients were placed in the lateral decubitus position (P < 0.01), and the mean differences in IOP between the eyes in the lateral decubitus position ranged from 2.9 to 4.1 mmHg. CONCLUSION: The IOP was higher in the dependent eye than in the non-dependent eye in anesthetized patients in the lateral decubitus position, and the IOP in the dependent eye increased in anesthetized patients compared with that in awakened and supine-positioned patients.

Adult↗

PubMed1996

The effect of four different surgical prone positions on cardiovascular parameters in healthy volunteers.

Twenty healthy volunteers were placed in four different surgical prone positions: on pillows, on an evacuatable mattress, on pelvic props and in the knee-chest position. The normal supine position was used as a control for the measurement of cardiovascular parameters. Mean arterial pressure was measured by automated oscillotonometry. Transthoracic electrical bioimpedance was used to measure cardiac output and heart rate. Cardiac index and total vascular resistance index were derived from these data. No significant changes in heart rate or mean arterial pressure occurred when the volunteers were moved from the supine position to any of the four prone positions or when returned to the supine position again. Cardiac index decreased significantly on going from the supine to the knee-chest position (20%) and onto the props (17%) but not onto the evacuatable mattress (11%) or the pillows (3%).

Adult↗

PubMed1976

Effect of the left lateral recumbent position compared with the supine and upright positions on placental blood flow in normal late pregnancy.

The placental blood flow was assessed by the 99mTc accumulation method in 10 normal pregnancies in the left lateral recumbent position accomplished by a 15 degree wedge and in the supine position. The postural change caused a 17% decrease in the mean placental accumulation rate, which was not statistically significant. Ten patients were moved from the left lateral recumbent position to the upright position, which caused a statistically significant 23% decrease in the mean accumulation rate. Other haemodynamic variables studied were the maternal heart rate and the systolic and diastolic blood pressures. The clinical significance of the haemodynamic changes produced by alterations in posture are briefly discussed.

Adult↗

PubMed1999

Twenty-four-hour pattern of intraocular pressure in the aging population.

PURPOSE: To characterize the 24-hour pattern of intraocular pressure (IOP) in a sample of the aging human population. METHODS: Twenty-one healthy volunteers 50 to 69 years of age were housed in a sleep laboratory for 24 hours. Experimental conditions were strictly controlled with a 16-hour light period and an 8-hour dark period. Sleep was encouraged in the dark period. Intraocular pressure was measured using a pneumatonometer every 2 hours (total of 12 times). Measurements were taken in both the sitting position and the supine position during the light/wake period but only in the supine position during the dark period. RESULTS: When the sitting IOP data from the light/wake period and the supine IOP data from the dark period were considered, elevation and reduction of IOP occurred around the scheduled lights-off and lights-on transitions, respectively. Mean IOP in the dark period was significantly higher than mean IOP in the light/wake period. The trough appeared at the end of the light/wake period, and the peak appeared at the beginning of the dark period. The magnitude of trough-peak difference was 8.6+/-0.8 mm Hg (mean +/- SEM). Cosine fits of 24-hour IOP data showed a significant 24-hour rhythm. When IOP data from just the supine position were analyzed, the trough-peak IOP difference was 3.4+/-0.7 mm Hg, with similar clock times for the trough and the peak. Cosine fits of supine IOP data showed no statistically significant 24 hour rhythm. CONCLUSIONS: Nocturnal elevation of IOP occurred in this sample of the aging population. The trough of IOP appeared at the end of the light/wake period, and the peak appeared at the beginning of the dark period. The main factor in the nocturnal IOP elevation appeared to be the shift from daytime upright posture to supine posture at night.

Aged↗

PubMed2000

Patient positioning in prostate radiotherapy: is prone better than supine?

PURPOSE: To assess potential dose reductions to the rectum and to the bladder with three-dimensional conformal radiotherapy (3D-CRT) to the prostate in the prone as compared with the supine position; and to retrospectively evaluate treatment position reproducibility without immobilization devices. METHODS AND MATERIALS: Eighteen patients with localized prostate cancer underwent pelvic CT scans and 3D treatment planning in prone and supine positions. Dose-volume histograms (DVHs) were constructed for the clinical target volume, the rectum and the bladder for every patient in both treatment positions. "Comparative DVHs" (cDVHs) were defined for the rectum and for the bladder: cDVH was obtained by subtracting the organ volume receiving a given dose increment in the prone position from the corresponding value in the supine position. These values were then integrated over the entire dose range. The prescribed dose to the planning target volume (PTV) was 74 Gy using a 6-field technique. To evaluate reproducibility, portal films were subsequently reviewed in 12 patients treated prone and 10 contemporary patients treated supine (controls). No immobilization devices were used. Deviations in the anterio-posterior (X) and cranio-caudal (Y) axes were measured. Mean treatment position variation, total setup variation, systematic setup variation, and random setup variation were obtained. RESULTS: Prone position was associated with a higher dose to the rectum or to the bladder in 6 (33%) and 7 (39%) patients, respectively. A simultaneously higher dose to rectum and bladder was noted in 2 (11%) patients in prone and in 7 (39%) patients in supine. Rectal and bladder volumes were frequently larger in prone than in supine: mean prone/supine volume ratios were 1.21 (SD, 0.68) and 1.03 (SD, 1.32), respectively. In these cases cDVH analysis more often favored the prone position. Mean treatment position variation and total setup variation were similar for both prone and supine plans. A higher systematic setup variation was observed in prone positioning: 2.7 mm vs. 1.9 mm (X axis) and 4.1 mm vs. 2.2 mm (Y axis). The random variation was similar for both prone and supine: 4. 0 mm vs. 3.6 mm (X axis) and 3.7 mm vs. 3.6 mm (Y axis). CONCLUSIONS: Prone position 3D-CRT is frequently, but not always, associated with an apparent dose reduction to the rectum and/or to the bladder for prostate cancer patients. As suggested by the increased mean prone/supine rectal volume ratio, the advantage of prone positioning for the rectum may be artifactual, at least partly reflecting a position-dependent rectal air volume, which may significantly vary from treatment to treatment. In the absence of immobilization devices, daily setup reproducibility appears less accurate for the prone position, primarily due to systematic setup variations.

Aged↗

PubMed2004

Oral airway resistance during wakefulness in eucapnic and hypercapnic sleep apnea syndrome.

The purpose of this study was to evaluate whether there was an abnormal increase of upper airway resistance in the sitting and supine positions in hypercapnic obstructive sleep apnea syndrome (OSAS) patients compared with eucapnic OSAS or normal controls as measured by impulse oscillometry (IOS) while awake. Twenty subjects without OSAS served as controls (group I), and 20 patients with moderate or severe eucapnic OSAS (group II) and another eight hypercapnic severe OSAS patients (group III) were studied. Group II was further divided into two subgroups. Group IIa consisted of 14 subjects whose BMI was less than 35 and group IIb of six subjects whose BMI was greater than 35. All subjects also had an overnight sleep study. Oral airway resistance (AR) (including impedance (Zrs), resistance (R) and reactance (X)) was measured by impulse oscillometry (IOS) (MasterScreen IOS, VIASYS Healthcare GmbH, Germany) in the upright (seated) position and then in the supine position while awake. The results demonstrated that in both group I and group II, Zrs was normal in the sitting position. However, there was a high Zrs in the supine position for group II patients. In contrast, in group III patients, there was a high Zrs in both the sitting and supine positions. In conclusion, upper airway resistance was increased both sitting and supine in the hypercapnic OSAS patients; this would presumably increase the work of breathing and might explain why these subjects were hypercapnic while awake, while eucapnic OSAS patients and normal controls were not. Secondly, the increased upper airway resistance in the supine position in the eucapnic OSAS patients may contribute to their OSAS.

Adult↗

PubMed2005

Diagnosis and management of lateral semicircular canal benign paroxysmal positional vertigo.

OBJECTIVE: Describe the diagnosis, treatment, and outcome of a group of 20 patients with lateral semicircular canal benign paroxysmal positional vertigo (LSC-BPPV). STUDY DESIGN AND SETTING: Retrospective review of 20 patients with LSC-BPPV (10 with geotropic and 10 with apogeotropic nystagmus) presenting to a tertiary balance center. Diagnosis was confirmed with infrared nystagmography in Dix-Hallpike positioning tests and supine positional tests. Patients were treated with one or more particle repositioning maneuvers. RESULTS: Addition of supine positional nystagmus tests to Dix-Hallpike positioning testing improves sensitivity in the diagnosis of LSC-BPPV. Treatment outcomes in the apogeotropic LSC-BPPV group were poorer than the geotropic LSC-BPPV group. SIGNIFICANCE: Adding supine positional testing to routine vestibular diagnostic testing will increase the identification of LSC-BPPV. Apogeotropic LSC-BPPV is more challenging to treat.

Adult↗

PubMed2004

Early enteral nutrition in mechanically ventilated patients in the prone position.

OBJECTIVE: To assess the tolerance of early enteral nutrition in critically ill patients receiving invasive mechanical ventilation in the prone position. DESIGN: Prospective, comparative study. SETTING: General intensive care unit in a university-affiliated hospital. PATIENTS: A total of 71 consecutive patients receiving invasive mechanical ventilation with early nasogastric enteral nutrition were studied for 5 days while being treated continuously in the supine position (supine position group, n = 37) or with intermittent prone positioning for severe hypoxemia (prone position group, n = 34). INTERVENTIONS: Inclusion occurred within 24 hrs of mechanical ventilation initiation. Daily 18-hr enteral nutrition via a 14F gastric tube was initiated. Prone position patients were turned every 6 hrs as long as PaO2/FiO2 remained at <150, with a FiO2 of 0.6 and positive end-expiratory pressure of 10; the head was slightly elevated. When supine, patients in both groups were semirecumbent. Residual gastric volume was measured every 6 hrs, and enteral nutrition was discontinued if it exceeded 250 mL or vomiting occurred. MEASUREMENTS AND MAIN RESULTS: The groups were similar for age, sex, Simplified Acute Physiology Score II, mortality, and risk factors for enteral nutrition intolerance. At baseline, PaO2/FiO2 was lower in prone position patients than in supine position patients (127 +/- 55 vs. 228 +/- 102; p <.001). As compared with supine position patients, prone position patients had significantly greater residual gastric volumes on days 1, 2, and 4 and experienced more vomiting episodes (median, 1 [interquartile range, 0-2] vs. 0 [interquartile range, 0-1]; p <.05). Enteral nutrition was stopped in 82% of prone position patients and 49% of supine position patients (p <.01) so that daily enteral nutrition volumes were lower with prone position patients. In the prone position group, vomiting occurred more frequently in the prone than in the supine position (relative risk, 2.5; 95% confidence interval, 1.5-4.0; p <.001). CONCLUSION: In critically ill patients receiving invasive mechanical ventilation in the prone position, early enteral nutrition is poorly tolerated. Prokinetic agents or transpyloric feeding and semirecumbency should be considered to enhance gastric emptying and to prevent vomiting in patients receiving mechanical ventilation in the prone position.

Adult↗

PubMed2001

Dual X-ray absorptiometry assessment of body composition in children with altered body posture.

Many children have contractures and/or deformities that preclude positioning in a fully supine position. The purpose of this study was to evaluate the effects of "poor" positioning on the assessment of body composition with dual X-ray absorptiometry (DXA) in thirty-seven normal child volunteers ages 3-16 yr. Multiple whole-body DXA scans of each child were performed: duplicate scans in the correct fully supine position, two scans while simulating different positions typical of children with contractures, and a scan while positioned in the full lateral position as a "worst-case" scenario. Also evaluated were the precision of duplicate measures in the altered positions, the effect of knee flexion contractures, and the impact of metallic orthopedic fixation devices. Errors in body composition assessment did occur from "poor" positioning. In those positions simulating children with contractures, the mean errors were 4-6% for measures of bone mineral content, 1-3% for lean body mass, and 5-11% for fat mass. Measures in the correct fully supine position and the contracted positions were highly correlated. The errors obtained by altering position were small. If errors of this magnitude are of significance, then corrective equations could be utilized to improve accuracy. Precise and reasonably accurate measures of body composition can be obtained with DXA in children with disabilities and deformities that preclude fully supine positioning.

Absorptiometry, Photon↗

PubMed1995

Isoproterenol infusion provokes vasovagal response without upright tilt in a patient exhibiting syncopal episodes.

We report a case of a patient with vasovagal syncope, in whom isoproterenol infusion provoked vasovagal response without upright tilting. We subjected the patient, who had had two previous syncopal and several presyncopal episodes, to upright tilting with isoproterenol infusion. Before a control tilt was performed for 10 min (80 degrees), the patient was placed in the supine position for 5 min. The control tilt did not provoke a vasovagal response. With isoproterenol being infused at a dose of 1 mu g/min, the sequence of positioning in the supine position for 5 min and upright tilting for 10 min was repeated. This dose of isoproterenol infusion did not provoke any vasovagal response in the patient, either in the supine or in the upright position. When the dose of isoproterenol infusion was then increased to 2 mu g/min, the heart rate increased to 121/min, but then suddenly dropped to 74/min; systemic arterial pressure simultaneously fell from 148/80 to 108/80 mmHg. The patient complained of palpitation and anxiety, and showed profound cold sweating. The drop in the heart rate and the fall in blood pressure occurred when the patient was in the supine position, indicating that, unlike upright tilting with isoproterenol infusion, venous return was not decreased at the beginning of vasovagal response in this setting. This observation suggests that isoproterenol infusion, even without upright tilting, may provoke the vasovagal response in some patients.

Adult↗

PubMed2001

Effects of supine body position and low radial accelerations on the visually perceived apparent zenith.

The visually perceived eye level (VPEL) has been shown to shift toward the lower part of the body in upright subjects facing toward the axis of rotation on a centrifuge. This shift occurs in the same direction as the shift in the gravito-inertial forces (Gis) produced by very low radial acceleration (centrifugation) combined with gravity. The purpose of this study was to determine whether the same phenomenon affects the visually perceived apparent zenith (VPAZ) in subjects in a supine position. Twelve supine subjects were instructed to set a luminous target to the VPAZ, either while they were in total darkness and motionless or while undergoing very low centrifugation. Data showed that Gis induced a VPAZ shift similar to that observed for the VPEL. Thus, as is the case for the VPEL, the corresponding logarithmic psychophysical function of the VPAZ may be considered to be a type of oculogravic illusion phenomenon with differences in the subjects' that differs from subject to subject, depending on the subject's sensitivity to low radial accelerations. Data on VPEL and VPAZ support the notion that the subjective perception of eye level in total darkness takes into account changes--even if extremely slight-in the direction of the gravito-inertial forces produced by the combination of gravity and low radial accelerations, although subjects are unaware of the Gi shift. However, depending on the intensity of the radial acceleration and the angular deviation of Gi relative to G, the shift of the VPEL and the VPAZ can be either amplified or attenuated. Moreover, differences between VPEL and VPAZ responses suggest two explanatory assumptions--namely, that this is (1) a peripheral phenomenon dependent on the neurophysiological anisotropy of the otolithic system or (2) a central phenomenon dependent on the relevance assigned to the peripheral information by the integrative sensory functions and the associative processes.

Adult↗

PubMed1987

[Effect of forced respiration on the stress on puncture channels of sutures in transverse laparotomies of the upper abdomen; experimental studies in the anesthesized dog].

In 11 mongrel dogs in propiophenylpromazine-pentobarbital-anaesthesia the influence of forced respiration on the load of puncture channels of a suture was investigated. For this horizontal suture in the upper abdominal wall, threads No. 3 USP and round needles No. ECT-4 were used. The experiments were carried out in supine position with stretched hindlegs, in supine position with relaxed hindlegs, in lateral position, and in hanging abdominal position. Measurements were performed with a selfconstructed resistance strain gauge element. Rising forced respiration pressure increased the inspiratory load of puncture channels, but there were no significant differences between spontaneous breathing and forced respiration with pressure of 10 cm H2O. In contrary to this there were highly significant differences between spontaneous breathing and forced respiration with pressure of 20 and 30 cm H2O (multiple variance analysis). For instance the load during forced respiration with a pressure of 30 cm H2O in supine position with relaxed hindlegs rose about 67% above pressure values of spontaneous breathing. It could be shown that the expiratory load in the puncture channels was not influenced by forced respiration pressure, but depended on the body position; in dogs it was minimal in side position (45-48 g), higher in supine position with relaxed hindlegs (67-71 g), even higher in supine position with stretched hindlegs (88-92 g), and maximal in hanging abdominal position (109-113 g). By this investigation the increase of load in the puncture channels during forced respiration with pressures of 20 and 30 cm H2O was quantified.

Abdomen↗