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Results for “Supine Position”

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PubMedDate not supplied

[Optimizing primary total hip replacement--a technique to effect saving of manpower].

PURPOSE: Development of a standardized surgical technique for total hip replacement thereby saving manpower (one assistant) by using a retractor system. METHOD: Total hip replacement is performed with the patient in a true lateral position on a tunnel cushion. By means of a direct lateral approach the pelvitrochanteric muscles are partially detached using an omega-shaped cut. The Bookwalter retractor is fixed dorsally on the operating table. The ring is centered keeping the greater trochanter in the middle. The Hohmann retractors are fixed to the ring to sufficiently expose the acetabulum. To insert the femoral stem the ring needs to be opened dorsally and the patient's leg is bent 90 degrees in the hip and the knee over the tunnel cushion. The muscles inserting at the greater trochanter are retracted by a separate Hohmann retractor with weight. In a case control study with matched pairs the patients treated with this technique were compared with those treated in supine position with the transgluteal approach. The number of assistants required and the operating time were assessed. RESULTS: All the hip replacements with the patient in side position were performed with one assistant, in supine position with two assistants. The operating time did not differ significantly (supine position 110 min/side position 112 min). The complication rate in both groups was comparable (one secondary wound healing, one transient ischalgia). CONCLUSION: The process of total hip replacement can be optimized. The described technique allows to spare one surgical assistant without prolonging the operating time.

Appointments and Schedules↗

PubMed2002

Pulmonary venous systolic flow: influence of gravity on pulmonary venous flow velocities assessed in patients with atrial fibrillation.

The origin of the pulmonary venous (PV) systolic flow wave is still unclear and could be the atrial relaxation and systolic descent of the atrioventricular plane, which decrease atrial pressure (suction) or raised PV pressure. In atrial fibrillation (AF), loss of atrial contraction and relaxation significantly modifies the systolic PV flow wave. The effect of recumbent positional changes on PV, however, has not yet been characterized in AF. The purpose of this study was to evaluate the effect of positional changes on systolic PV flow in patients with AF studied by transesophageal echocardiography. The study group consisted of 45 patients with AF (34 patients with AF, alone, and 11 patients with mitral stenosis [MS]). To assess the influence of left atrial pressure, we included patients with MS and AF. Pulsed wave Doppler transesophageal echocardiography of the left and right upper PV were performed in the left lateral recumbent position in all patients and repeated records were obtained with the subject in the supine position in 25 (AF alone: n = 20, MS: n = 5) of 45 patients. In the left lateral recumbent position, the systolic PV flow velocity and systolic fraction of the left PV, which were recorded on the recumbent subject's lower side, were significantly increased compared with those of the right PV in both AF alone and MS with AF (33.9 +/- 10.8 vs 13.8 +/- 6.4 cm/s, 0.45 +/- 0.09 vs 0.20 +/- 0.10 in AF alone; 30.2 +/- 11.7 vs 14.6 +/- 6.0 cm/s, 0.43 +/- 0.12 vs 0.20 +/- 0.07 in MS, respectively, P < .01). By changing the position from the left lateral to the supine position, systolic PV flow velocity and systolic fraction of the left and right PV became the same (29.3 +/- 8.4 vs 27.9 +/- 8.4 cm/s, 0.39 +/- 0.09 vs 0.36 +/- 0.06 in AF alone, 23.5 +/- 8.8 vs 27.5 +/- 5.0 cm/s, 0.35 +/- 0.08 vs 0.35 +/- 0.09 in MS, respectively). These findings show that the PV volume (hydrostatic pressure) significantly modifies systolic PV flow wave in patients without atrial contraction and relaxation. We should take into consideration the body position on which PV flow is studied.

Aged↗

PubMed1997

Cardiovascular status after postural change in compensated cirrhosis: an argument for vasodilatory concept.

It seems that hypervolemia and vasodilatation coincide in compensated cirrhosis, but neither rank nor importance of these factors has been fully clarified in adaptive response to postural change. We studied, with gated equilibrium radionuclide angiography and thoracic electrical bioimpedance the hemodynamic status of 19 patients with compensated cirrhosis and 18 healthy subjects in upright and supine positions. In the upright position, the cirrhotic patients were hypotensive and had decreased peripheral vascular resistance despite increased cardiac output. The transition to the supine position was accompanied by a significant fall in the heart rate and an increase in the stroke volume in both controls (92 +/- 22 to 63 +/- 10 beats/min, and 38 +/- 9 to 62 +/- 19 ml/m2, respectively) and cirrhotic patients (101 +/- 20 to 79 +/- 13 beats/min, and 44 +/- 15 to 63 +/- 19 ml/m2, respectively). Besides, the diastolic arterial pressure fell in controls from 89 +/- 9 mmHg to 81 +/- 11 mmHg; p < 0.01, while it remained unchanged in cirrhotic patients (77 +/- 17 vs 82 +/- 13 mmHg). In the supine position, the cirrhotic patients presented tachycardia and left ventricular hyperkinesy (increased velocity of left ventricular filling and emptying). In conclusion, these results show that in compensated cirrhosis the decreased arterial tone and peripheral blood pooling are important factors of adaptive hemodynamic reaction to postural change.

Adult↗

PubMed2003

Influence of body posture on intestinal transit of gas.

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 investigated. AIM: To determine the effect of body posture, upright versus supine, on intestinal transit of gas loads. SUBJECTS: Eight healthy subjects without gastrointestinal symptoms. METHODS: In each subject a gas mixture was continuously infused into the jejunum (12 ml/min) for three hours, and gas evacuation, clearance of a non- absorbable gaseous marker, perception, and abdominal girth were measured. Paired studies were randomly performed in each subject on separate days in the upright and supine positions. RESULTS: In the upright position, intestinal gas retention was much smaller than when supine (13 (52) ml v 146 (75) ml retention at 60 minutes, respectively; p<0.05), and clearance of the gas marker was expedited (72 (10)% clearance v 49 (16)% at 60 minutes, respectively; p<0.05). The gas challenge test was well tolerated both in the upright and supine positions without abdominal distension. CONCLUSION: Body posture has a significant influence on intestinal gas propulsion: transit is faster in the upright position than when supine.

Adult↗

PubMed1980

Effect of labetalol on plasma catecholamines at rest and during increased sympathetic activity.

Mean arterial blood pressure was decreased by intravenous labetalol in 14 hypertensive patients, resting in the supine position, when standing, during exercise and during psychic stress. Heart rate was unchanged during psychic stress and while resting in the supine position, whereas it fell in the other situations. Plasma noradrenaline increased in all situations after labetalol compared to control studies. Plasma adrenaline only increased when standing and during stress, and there was no correlation between changes in plasma noradrenaline and adrenaline. Blood glucose rose significantly after labetalol in the supine position, whereas it only tended to increase in the other experimental situations. The changes in plasma noradrenaline and blood glucose induced by labetalol are identical to those seen after pure alpha-adrenoceptor blockade. The beta-adrenoceptor blocking property of labetalol may contribute to the higher plasma concentration of noradrenaline when standing and during exercise as this has been found during pure beta-adrenoceptor blockade.

Adult↗

PubMed1982

Passive leg raising does not produce a significant or sustained autotransfusion effect.

Passive leg raising is widely used to treat hypotension associated with hypovolemia. Presumably gravity causes a central translocation of leg venous blood and an increase in filling pressure, cardiac output, and arterial pressure. Ten healthy volunteers, 25 to 35 years old, had measurements of heart rate, blood pressure, and cardiac output in the supine position after 20 sec and 7 min of 60 degrees passive leg elevation. The protocol was performed 3 and 45 min after the subjects changed from an ambulatory upright to a supine position. Stroke volume and cardiac output increased transiently (8-10%) when the legs were raised after 3 min rest in the supine position. By 7 min of leg elevation, these beneficial effects disappeared. After 45 min supine, leg raising had no effect on stroke volume or cardiac output but increased blood pressure (4 mm Hg) by increasing peripheral resistance (15%). Thus, leg raising, like application of the MAST trousers, fails to produce any sustained increase in cardiac output or stroke volume. Small venous leg volumes and time-dependent changes in the distribution of venous volume and compliance may explain the absence of any sustained 'autotransfusion' effect.

Adult↗

PubMed2002

Autonomic nervous system and left ventricular hypertrophy in essential hypertension.

BACKGROUND: Patients with essential hypertension (EH) and left ventricular hypertrophy (LVH) have an increased risk of cardio-vascular complications. Alterations in the autonomic nervous system (ANS) activity may play a role in the development of serious cardiac arrhythmias and mortality in these patients. AIM: To examine the activity of ANS in patients with established EH in relation to the presence of LVH. METHODS: The study group consisted of 70 subjects: 50 patients with untreated EH (mean age 44.4+/-12.7 years, 28 patients without LVH and 22 with LVH), and 20 age-matched healthy volunteers. ANS reactivity was assessed using heart rate variability (HRV) analysed during tilt table testing at 60 degrees. The following 5-min time-periods were analysed: (A) before tilting (supine position), (B) initial period of tilting, (C) last 5 min of tilting, and (D) immediately after completion of tilt test (after return to supine position). RESULTS: Patients with EH without LVH had a higher increase of LF/HF values (period B versus period C) compared with controls (p<0.05). The change from tilt to supine position caused significantly lower change in lnHF values in patients with EH and LVH than in controls (p<0.01) or patients with EH without LVH (p<0.005). In patients with EH and LVH a significant correlation between HF and LVmass/height (r=-0.5, p<0.01) was noted. Compared with healthy controls, patients with EH and LVH had significantly lower HRV parameters [lnLF values were significantly lower in all analysed periods, (p<0.05), and lnHF - during period D, (p<0.01)] whereas LF/HF ratio assessed during period D was significantly higher (p<0.05). CONCLUSIONS: In patients with EH without LVH a relative dominance of sympathetic activity is present. LVH in EH leads to a decrease in vagal drive and progressive inhibition of parasympathetic activity, both of which decrease HRV. These changes may play an important role in the electrical instability of hypertrophied myocardium.

Journal Article↗

PubMed1996

Results of levator-advancement blepharoptosis repair using a standard protocol: effect of epinephrine-induced eyelid position change.

PURPOSE: Blepharoptosis repair by levator advancement is successful in most instances, but the postoperative eyelid level is not uniformly predictable. This study was undertaken to evaluate the possible effect of epinephrine (from local anesthetic) on eyelid position. METHODS: Seventeen adults with acquired unilateral ptosis as a result of levator aponeurosis dehiscence underwent levator aponeurosis advancement. The distance between the upper eyelid margin and the central corneal light reflex was measured preoperatively with the patient in both the upright and the supine position, 10 minutes after injection of 1.0 mL of anesthetic solution (2% lidocaine with 1:100,000 epinephrine and 12 U hyaluronidase per mL) in the supine position, intraoperatively after skin closure in the supine position, and 1 week or more postoperatively in the upright position. The ptotic lid was positioned intraoperatively in relation to the contralateral unoperated lid according to the change (presumably) induced by epinephrine stimulation of Müller's muscle. RESULTS: Eleven (65%) of the 17 patients had final postoperative lid positions within 1 mm between eyes. Two patients (12%) had undercorrection. Four patients (24%) had overcorrection by > 1 mm. The overcorrected lids were satisfactorily positioned, however, and none required further surgery; in 3 of these 4 patients, the unoperated lid had become ptotic, probably as a result of Hering's law. Differences between operated and unoperated lids and between the different times of measurement were analyzed. Significant changes in lid position occurred in the ptotic lids after injection (mean, +1.1 +/- 1.5 mm; median, +1.0 mm; P = .004) and in the final intraoperative difference between operated and unoperated lids (mean, +0.8 +/- 0.9 mm; median, +1.0 mm; P = .003). The change in the unoperated lid from preoperative upright to preoperative supine was significantly greater in the 6 failures (mean, -0.8 +/- 0.6 mm; median, -1.0 mm) than in the 11 successful outcomes (mean, +0.1 +/- 0.8 mm; median, 0.0 mm; P = .03). The change in unoperated lid position after injection of the ptotic lid was significantly greater in the failures (mean, +0.4 +/- 0.5 mm; median, +0.3 mm) than in the successful cases (mean, -0.2 +/- 0.4 mm; median, 0.0 mm; P = .02). CONCLUSION: Although it seems intuitively reasonable and clinically appropriate to account for the stimulatory effect of epinephrine during ptosis surgery, such intraoperative compensation alone did not yield a universally successful outcome in this study.

Adult↗

PubMed1997

[Laparoscopic cholecystectomy--effect of position changes and CO2 pneumoperitoneum on hemodynamic, respiratory and endocrinologic parameters].

UNLABELLED: The effect of laparoscopic cholecystectomy on cardiopulmonary and endocrinological parameters results from various factors such as increased intraabdominal pressure (IAP), CO2, and the positioning. However, positioning has not yet been regarded. Reliable examination of the individual influencing factors requires standardized anesthesiological procedure and constant IAP. Presently, the effect of positioning is observed separately from those effects caused by the pneumoperitoneum with CO2 (PP) under standardized conditions. METHODS: 40 patients with no history of cardiopulmonary disease were analyzed. Preoperative medication, induction and management of general anesthesia, positioning of the patient and IAP (12 mmHg) were standardized. Hemodynamic, respiratory and endocrinological parameters were determined with the patient in a supine position and in the position typical for the procedure (15 degrees head-down and 10 degrees slant to the left), each with and without PP. Heart rate (ECG), endexpiratory pCO2 (peECO2), invasive blood pressure (radial art.), central venous pressure, partial arterial O2 saturation (psaO2), and ventilation pressures (peak, plateau) were monitored throughout anesthesia. The parameters pH, pCO2, BE, HCO3-, COHb, vasopressin, lactate, and ammonia were analysed in arterial and venous blood samples at predetermined set points: base line, 10 min after CO2 insufflation, 10 min after desufflation, and 1 h after extubation (cf. table 1). Statistical analysis was performed using the Wilcoxon-test with p < or = 0.05 considered statistically significant. RESULTS: Insufflation of CO2 lead to a 12% increase of heart rate in supine position and to even 18% in the position required for surgery. Same significant changes were observed for arterial blood pressure (21 or respectively 28%). Central venous pressure increased by more than 200% after CO2 insufflation. Endexpiratory pCO2 increased by 2.4 mmHg after CO2 insufflation in the supine position and by 5 mmHg in the surgical position. Ventilation pressures increased significantly by 16%. Analysis of the effect of PP on blood gases showed that pH decreased from 7.47 to 7.43, and arterial pCO2 increased by 5.1 mmHg to 38.7 mmHg and increased further after desufflation to values of up to 43.9 mmHg. Arterial pO2 decreased steadily (18% after insufflation). Vasopressin plasma levels increased exponentially from 3.03 to maximal values of 104.45 pg/ml. Ammonia and lactate showed the expected, nearly identical course. Lactate increased within the clinically and methodically irrelevative range, from 1.12 to 1.159 mmol/l. Ammonia decreased by 29%. CONCLUSIONS: The observed changes, i.e. heart rate, central venous pressure, and arterial blood pressure are caused and altered by CO2 insufflation and the various positioning of patients. The increased vasopressin concentration more than likely contributes to these changes. The query whether the position of the patient also causes a change in respiratory parameters and blood gas analysis cannot be differentiated except for the end-tidal pCO2. Inspite of the observed changes no cardiopulmonary complications occurred in this patient group. Therefore, it seems possible to omit invasive monitoring in cardiopulmonary healthy patients. In patients with concomitant history of cardiopulmonary disease, however, deteriorations due to laparoscopy should be thoroughly taken into consideration and studied further.

Acid-Base Equilibrium↗

PubMed1988

Pleural liquid pressure measured with rib capsules in anesthetized ponies.

Pleural liquid pressure was measured at end expiration in 11 spontaneously breathing anesthetized ponies in the prone and supine positions. A liquid-filled capsule was implanted into a rib to measure pleural liquid pressure with minimal distortion of the pleural space (Wiener-Kronish et al., J. Appl. Physiol. 59: 597-602, 1985). Capsule position relative to lung height was measured from thoracic radiographs taken in each position. In each body position, pleural liquid pressure was most negative in the superior lung regions and least negative in the inferior lung regions. In the supine position, the magnitude of the vertical gradient in pleural liquid pressure was 0.67 cmH2O/cm ht and was not significantly different from 1 cmH2O/cm ht. In the inferior lung regions (less than 50% lung ht), pleural liquid pressure averaged -1.3 cmH2O, indicating a low transpulmonary pressure over the region of the chest where most of the lung mass is located. When animals were in the prone position, the magnitude of the vertical gradient in pleural liquid pressure was 0.14 cmH2O/cm ht and was not statistically different from 0 cmH2O/cm ht. In each body position, mean transpulmonary pressure, measured postmortem, was similar to the estimated magnitude of pleural liquid pressure at 50% lung ht. This suggests that pleural liquid pressure is closely related to pleural surface pressure. These results are consistent with the poor ventilation distribution and reduced lung volumes measured in anesthetized horses in the supine position compared with values measured in horses in the prone position.

Animals↗

PubMed1986

[Ergometry procedures independent of body weight in children with special reference to blood pressure behavior in stress].

UNLABELLED: For the purpose of investigating differences in terms of gender and methodology, a group of 80 healthy children engaged in leisure-time sport activities (male: n = 50; 10.9 +/- 1.1 years; female: n = 30; 11.5 +/- 1.1 years) was divided into 3 groups, which were then subjected to different ergometric procedures. In group I, boys and girls were compared in a bicycle ergometry in an upright seated position. In group II, a bicycle ergometry in upright seated position was compared with a bicycle ergometry in a supine position. In group III, a bicycle ergometry in upright seated position was compared with a treadmill exercise. Bicycle ergometry was started at 25 W; workload was increased in steps of 25 W every 3 min until the children felt exhausted. RESULTS: No differences with respect to gender were found for maximum oxygen uptake, maximum heart rate and maximum lactate. The relevant parameters were also similar on submaximal levels of exercise intensity. All children reached a degree of thorough physical exhaustion at heart rates close to 200 X min-1. As in adults, maximum oxygen uptake decreased in the following order: treadmill exercise greater than bicycle ergometry in upright seated position greater than bicycle in supine position. Systolic and diastolic blood pressure on the various levels of exercise were lower than among adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗

PubMed2004

Non-apneic snoring and the orthodontist: radiographic pharyngeal dimension changes with supine posture and mandibular protrusion.

OBJECTIVE: To evaluate the radiographic changes that occur in the pharynx and surrounding structures with alteration of posture from the upright to the supine position and the effect that mandibular protrusion whilst supine has on these dimensions. DESIGN: Prospective cephalometric study. SETTING: University Dental Hospital and School. SUBJECTS AND METHOD: This prospective study involved 35 consecutively referred adults with proven non-apneic snoring. Lateral skull radiographs were obtained with the subjects upright in occlusion, supine in occlusion and supine with the mandible protruded to the maximum comfortable position. Radiographs were traced and digitized, and the pharyngeal dimensional changes and hyoid position were examined. Males and females were examined separately. RESULTS: Radiographic pharyngeal dimensions were changed with altered posture, resulting in significant reductions in the minimum post-palatal (p<0.01) and post-lingual (p<0.05) airway measurements in the supine position. Mandibular protrusion whilst in the supine position produced increases in the functioning space for the tongue. CONCLUSION: A supine posture results in significant reductions in pharyngeal airway measurements of non-apneic snorers. Mandibular protrusion whilst in the supine position produces an increase in the functioning space for the tongue.

Adult↗

PubMed1993

Transfer of embryos into the uterus: how much do technical factors affect pregnancy rates?

OBJECTIVE: Our objective was to identify the effect on outcome of (a) ultrasound-assisted embryo transfer, (b) the use of different embryo transfer catheters, and (c) the length of time the patients remain in the supine position after embryo transfer. SETTING: The setting was a private fertility center. SUBJECTS: This was a prospective study of 178 in vitro fertilization and embryo transfers (IVF-ET) and 63 frozen embryo replacements (FER). RESULTS: The pregnancy rate was 28.7% following IVF-ET and 31.8% for FER. Ultrasound-assisted transfer did not affect the outcome (29 vs 30.3%). There was no difference in the performance of the Wallace and Frydman catheters with regard to outcome (30.3 vs 30.7%). Although there was an increase in pregnancy rate as the time interval in the supine position after ET increased, this needs a larger study. CONCLUSION: The parameter studies did not affect the outcome of IVF/ET or FER. Some factors encouraged us to recommend ultrasound-assisted transfer in some cases, and the use of a Frydman catheter for transfer and to encourage the supine position after transfer for longer periods.

Abdomen↗

PubMed1982

Measurement of instantaneous blood-flow velocity in the human aorta using pulsed Doppler ultrasound.

The reproducibility and ease of use of a pulsed Doppler system has been investigated in 27 normal subjects. Measurements were performed in the ascending aorta and the aortic arch in the sitting and supine position. Good quality recordings were obtained in over 90% of the subjects. Maximum velocities of 120 and 108 cm . s-1 were found in the supine position of the ascending aorta in males and females respectively, while the corresponding acceleration were 2254 and 2148 cm . s-2. When moving from the sitting to the supine position, changes in integral under the mean and maximum velocity curve, which is supposed to be proportioned to stroke volume, were approximately 30% both in the ascending aorta and in the aorta arch. Making certain assumptions about dimensions of the aorta, reasonable values for cardiac output could be calculated in all subjects. The reproducibility of the measurements was tested by making ten repeat measurements in five subjects. The mean variation coefficient was between 6 and 11% for all measured variables. It is concluded that blood-flow velocity can be measured in the ascending aorta and the aortic arch using pulsed ultrasound and that the method has a reproducibility which permits measurements of changes in the flow and flow velocity of over 10%.

Adult↗

PubMed2005

Clinical comparison of tympanic membrane displacement with invasive ICP measurements.

OBJECTIVE: Tympanic membrane displacement (TMD) measurements may be useful in the management of patients with hydrocephalus if they can be directly associated with measurements of ICP. We have compared TMD measurements using the Marchbanks Measurement System with invasive ICP monitoring. METHODS: Twenty-nine patients who were undergoing routine invasive monitoring using a Camino fibre optic ICP measurement system as part of their clinical management were studied. Simultaneous measurements of ICP and TMD in both sitting and supine positions were successfully made in thirteen patients. RESULTS: Thirty-nine pairs of readings were obtained. The invasive ICP readings varied from 1 to 36 mmHg in the supine position and from -12 to +35 mmHg sitting. Corresponding TMD values varied from 275 to +277 nL in the supine position and -133 to +466 nL sitting. Linear regression showed a significant negative relationship between the two measurements (r = -0.57, p = 0.0013). CONCLUSIONS: There is a strong negative linear association between mean TMD and invasively measured ICP and this relationship is highly significant. Nevertheless, TMD is a poor surrogate for ICP in clinical terms because the predictive limits of the linear regression are too wide. However, serial intra-patient measurements may be useful to determine changes in ICP with time.

Acoustic Impedance Tests↗

PubMed2001

Comparison of the response to the prone position between pulmonary and extrapulmonary acute respiratory distress syndrome.

OBJECTIVES: To determine whether the response to the prone position differs between acute respiratory distress syndrome (ARDS) resulting from a pulmonary cause (ARDSp) and that from an extrapulmonary cause (ARD-Sexp). DESIGN AND SETTING: Prospective observational study in a medical ICU of a university-affiliated hospital. SUBJECTS: A consecutive series of 31 patients with ARDSp and 16 with ARDSexp within 3 days of onset of ARDS. INTERVENTION: Prone position for at least 2 h. MEASUREMENTS AND RESULTS: In ARDSp, compared with the supine position (121 +/- 49 mmHg), PaO2/FIO2 was not increased after 0.5 h but was increased after 2 h in the prone position (158 +/- 60 mmHg). In ARDSexp, compared with the supine position (106 +/- 53 mmHg), PaO2/FIO2 was increased after 0.5 h (155 +/- 91 mmHg), but was not further changed after 2 h. Marked oxygenation response (increase in PaO2/FIO2 > 40% from baseline) after 0.5 h was 23% in ARDSp and 63% in ARDSexp, and that after 2 h was 29% and 63%, respectively. Static respiratory compliance decreased in the prone position in ARDSexp (30 +/- 11 ml/cmH2O at baseline, 27 +/- 11 after 0.5 h and 25 +/- 9 after 2 h) but not in ARDSp. Consolidation score as determined on the first chest radiography taken in the prone position decreased to a greater degree in ARDSexp (-2.4 +/- 4.1) than in ARDSp (0.3 +/- 4.1). CONCLUSION: Pulmonary ARDS and extrapulmonary ARDS in their early stages respond differently to the prone position with regard to the time course of oxygenation, respiratory mechanical behaviour, and radiographic change. These findings suggest that the early pathophysiology of ARDS differs according to the type of primary insult to the lung.

Aged↗

PubMed2001

[Anterior chamber structural change in postural variation in pseudoexfoliation syndrome].

PURPOSE: The anterior chamber structure in the supine position and the prone position was investigated with ultrasound biomicroscopy (UBM) in pseudoexfoliation syndrome (PE). METHODS: We studied 12 eyes of 12 PE subjects. Patients were placed in the supine position for 30 minutes, after which UBM was performed. The UBM was repeated after 30 minutes in the prone position. Anterior chamber depth (ACD), angle opening distance 500 microns (AOD 500), and angle recess area (ARA) in 4 quadrants were measured. RESULTS: Following the postural change from the supine position to the prone position, ACD decreased significantly (p < 0.0001). AOD 500 and ARA decreased significantly in the superior (AOD 500: p < 0.05, ARA: p = 0.03) and temporal quadrants (AOD 500: p < 0.0001, ARA: p < 0.0001). CONCLUSIONS: The anterior chamber structural change was greater in the temporal and superior quadrants in the PE eyes. This corresponds with previous reports that zonular involvement by pseudoexfoliation material is more pronounced temporally and superiorly.

Anterior Chamber↗

PubMed1992

Lateral dual-energy radiography: artifact error from rib and pelvic bone.

A lateral projection of the lumbar spine with dual-energy radiography (DER) may be a more sensitive tool for the detection of vertebral demineralization than the standard anterior-posterior (AP) DER measurement. The lateral view allows measurement of the vertebral body and selective measurement of the central trabecular compartment, excluding the majority of the cortical envelope and posterior vertebral elements. The lateral DER typically contains L2-4 in the region of interest. The present study was designed to investigate the frequency and bone mineral content (BMC) contribution of rib to the L2 vertebral body BMC measurement in a lateral view DER scan. In addition, the frequency of pelvic overlap of L4 was evaluated. All patients were scanned in the supine position. Abdominal CT images of L2 were examined in 20 women aged 28-82 years to determine the frequency of rib and pelvic interference. QCT images of L2 also were examined in an additional 35 women aged 20-82 years to further investigate the frequency of rib overlap and to calculate the potential contribution of rib superimposition to the L2 BMC in a lateral projection. Pelvic overlap of L4 occurred in 15% of the 20 cases reviewed. Rib overlapped the L2 vertebral body in 100% of the L2 images. The expected contribution of rib BMC to L2 BMC in a lateral DER scan was 10.4% on average. There was no relationship between the percentage of rib BMC contribution and age and relatively poor correlations between rib BMC and that of either the vertebral body or the central trabecular compartment of L2. We conclude that supine positioning allows routine inclusion of L3 and L4 in a lateral lumbar scan. Results also suggest that L2 should be excluded from DER scans on patients scanned in either the lateral decubitus or supine position.

Adult↗