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Results for “Supine Position”

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PubMed1998

Prone position ultrasonography in silicone filled eyes.

PURPOSE: To evaluate the efficacy of a new technique of prone position ultrasonography in cases with silicone filled eyes. METHODS: Forty patients with prior pars plana vitrectomy and silicone oil instillation referred to a tertiary eye care centre were the subjects of this study. A prospective clinical trial was undertaken to evaluate the efficacy of prone position ultrasonography in addition to routinely performed supine position ultrasonography in these patients. The technique was undertaken by 2 independent observers and compared with the findings by indirect ophthalmoscopy or surgical results. Interobserver variability was also calculated. RESULTS: Two spikes were observed in supine position corresponding to the intravitreal silicone oil surface and the sclera, whereas a single spike corresponding to the sclera was observed in prone position. Supine position ultrasonography yielded a diagnostic accuracy of 61.8%, which increased to 96.7% when the procedure was supplemented with prone position ultrasonography. Specificity increased from 75 to 100% by the addition of this adjuvant procedure, however, with no significant difference in the interobserver variability ('K'=0.67 Vs 'K'= 0.62). CONCLUSION: Prone position ultrasonography is a useful adjunct to the routinely performed supine position ultrasonography in silicone filled eyes and increases the diagnostic yield.

Diagnostic Techniques, Ophthalmological↗

PubMed2002

MR-guided interventional breast procedures considering vacuum biopsy in particular.

Histologic work-up of just MR-detected breast lesions has become essential with increasing use of contrast-enhanced MR imaging. In the present article an overview is given about the different MR-guided breast interventions, performed since 1990. Presently, for reasons of costs and image quality closed magnets are most widely used. The following approaches have been described: MR-guided freehand localization in supine position, stereotaxic localization in supine position and most frequently used localization in the prone position by means of a compression device that immobilises the breast to prevent tissue shift during intervention. Only limited experience exists with interventions on open magnets. MR-guided wire localization is a well-established procedure. Recently, percutaneous vacuum biopsy of enhancing breast lesions has become possible under MR guidance. The new system allows accurate and safe access to lesions in any location of the breast and direct check-up of representative excision by visualisation of the cavity. Thus reliable histologic evaluation of lesions smaller than 10 mm is possible with this approach.

Biopsy, Needle↗

PubMed2006

[Intraocular pressure measurement during the day and night for glaucoma patients and normal controls using Goldmann and Perkins applanation tonometry].

OBJECTIVE: Our aim was to evaluate intraocular pressure (IOP) levels in primary open angle glaucoma (POAG) patients and healthy controls during both the day and night while measuring in an upright as well as in a supine position. METHODS: In a prospective clinical trial, 30 glaucoma patients on topical treatment and 50 healthy controls received IOP measurements every 4 h for a 24 h period starting at 8 am. Additionally, blood pressure and heart rate were measured and perfusion pressures were calculated. At 12 am IOP was initially measured in a sitting position and then, after 20 min, in a supine position. At midnight this was carried out conversely. At 4 am IOP was measured in a supine position; all other measurements were performed in a sitting position. Measurements in the sitting position were performed by Goldmann and Perkins tonometry and in a supine position by Perkins tonometry. RESULTS: IOP was 1 mmHg lower in Perkins tonometry measurements compared to Goldmann tonometry. There was no difference between the two patient groups. In a supine position, IOP measured by Perkins tonometry was higher than in an upright position. At 12 am the difference was 1.8 mmHg+/-2.7 mmHg (p=0.001) in healthy subjects and 1.3+/-2.7 mmHg (p=0.013) in the POAG patients. At 12 pm the increase of IOP in the supine position was even more pronounced with 2.4+/-3.4 mmHg in healthy subjects and 5.6+/-3.2 mmHg in the POAG patients (p=0.001). The blood pressure and the perfusion pressure were lowest during night measurements. CONCLUSIONS: During diurnal IOP measurements in an upright position there were no statistically significant differences in IOP changes between groups. However, in a supine position IOP was significantly higher than in a sitting position and increased more in the glaucoma patients than in healthy controls. This observation might be due to a faulty regulation of the fluid shift in glaucoma patients and could cause progression of glaucomatous damage.

Aged↗

PubMed2006

Comparison of different extubation techniques in lumbar surgery: prone extubation versus supine extubation with or without prior injection of intravenous lidocaine.

The aim of this study was to evaluate the incidence of coughing and breath holding in patients undergoing lumbar surgery extubated in prone position, supine position, or supine position with intravenous lidocaine before extubation. About 105 ASA I to II patients undergoing lumbar surgery were extubated in prone position in group P (n = 35), in supine position in group S (n = 35) and in supine position with intravenous 1.5 mg/kg lidocaine 10 minutes before extubation in group SL (n = 35). The number of patients who coughed and demonstrated breath holding was noted at emergence period. The time of loss of monitoring while repositioning the patient was recorded. The frequency of cough in group S was higher compared with group P at 1 minute after extubation (P = 0.008). Two and three minutes after extubation, the patients in group S demonstrated higher cough incidence compared with groups P and SL (P < 0.05). The incidence of breath holding in the first 6 minutes was lower in group P (n = 11) compared with groups S (n = 29) and SL (n = 25)(P = 0.001). The loss of monitoring time was longer in groups S (62 +/- 40 s) and SL (53 +/- 39 s) when compared with group P (0 s) (P < 0.01). Prone emergence and supine emergence with intravenous lidocaine provides an alternative approach to conventional supine emergence and prone extubation offers less cough and breath holding and continuation of monitoring.

Adult↗

PubMed1992

The influence of posture on the response to loop diuretics in patients with chronic cardiac failure is reduced by angiotensin converting enzyme inhibition.

The diuretic and natriuretic response to an intravenous dose of frusemide 40 mg was assessed in the erect and supine positions in 10 patients with cardiac failure who were being treated with enalapril 10 mg twice daily in addition to diuretics (Enalapril group) and in 10 patients with cardiac failure taking diuretics alone (Control group). Total 4 h diuresis in the erect position was 728 ml and in the supine position was 824 ml in the patients taking enalapril compared to 655 ml in the erect position and 1166 ml in the supine position in those patients taking diuretics alone. Total 4 h natriuresis in the erect positions was 78 mmol and in the supine position was 85 mmol in patients taking enalapril 10 mg twice daily but in those patients taking diuretics alone total 4 h natriuresis in the erect position was 67 mmol increasing to 120 mmol in the supine position. Measurements of plasma renin activity and plasma angiotensin II concentration confirmed effective converting enzyme inhibition, in the group of patients taking enalapril, but in those patients taking diuretics alone the erect position was associated with an increase in plasma renin activity, and plasma concentrations of angiotensin II and aldosterone. We conclude that the renin angiotensin system is a major factor in mediating the effect of posture on loop diuretic drugs.

Adult↗

PubMed1998

Effects of exaggerated lithotomy position on ventilation and hemodynamics during radical perineal prostatectomy.

Ventilation and haemodynamics were studied in nine anaesthetized male patients undergoing perineal prostatectomy in the exaggerated lithotomy position (flexed, head-down position). In the flexed head-down position, as compared to the supine position, there was a significant decrease in arterial oxygen tension (13.1 +/- 2.1 to 11.2 +/- 1.1 kPa, p < 0.001), a significant increase in carbon dioxide tension (4.6 +/- 5.7 to 5.7 +/- 0.2 kPa, p < 0.001) and shunt fraction (7.8 +/- 2.3 to 14.0 +/- 3.0%, p < 0.01). There were also increases in pulmonary wedge pressures (11.3 +/- 2.9 to 17.9 +/- 2.9 mmHg, p < 0.01), mean pulmonary artery pressures (17.6 +/- 3.8 to 25.2 +/- 3.5 mmHg, p < 0.001) and central venous pressures (11.9 +/- 2.1 to 14.7 +/- 2.8, p < 0.05). Mean arterial pressure fell from 92 +/- 14 to 75 +/- 10 mmHg (p < 0.05). Heart rate and cardiac output were unchanged. All these changes had already been seen but to a lesser extent when the patients were positioned in the flexed supine position. When the patients were returned to the supine position following surgery, arterial oxygen tension was returned to baseline values. Mean pulmonary artery, pulmonary capillary wedge and central venous pressures also fell significantly. It is concluded that the extreme exaggerated lithotomy used during surgery results in impaired oxygenation and increased cardiac filling pressures but to acceptable levels in healthy anaesthetized patients. All values returned to normal when patient position was normalized after surgery.

Aged↗

PubMed2000

The effects of body positioning on sucking behaviour in sick neonates.

UNLABELLED: Some infants show better oxygenation in the prone position compared to the supine position while they are bottle-fed; however, the reason for this phenomenon is not clear. The purpose of this study was to obtain a better understanding of the effects of body position on the oral feeding performance, i.e. the sucking pressure, frequency, efficiency, and ventilation. A total of 14 infants (12 full-term, 2 preterm), who often showed O2 desaturation (SpO2 < 90) during oral feeding, were enrolled in the study. The infants were fed either in the supine position or in the prone position throughout feeding. Oxygen saturation was recorded with a pulse oxymeter. The sucking pressure was measured with a 1 mm I.D. silicone tube inserted into the artificial nipple. The ventilation volume during bottle feeding was measured with a pneumotachograph. The prone position resulted in better oxygenation (97.2 +/- 0.6% prone, 92.5 +/- 0.9% supine, P < 0.05) and larger tidal volume (6.4 +/- 0.8 ml/kg prone and 4.9 +/- 0.6 ml/kg supine, P < 0.05), although the minute ventilation during bottle-feeding was not different from that in the supine position. In the prone position, the sucking pressure and frequency were higher and the duration of each suck was shorter. CONCLUSION: Sucking in the prone position may to some extent reduce disadvantages of oral feeding on ventilation.

Gestational Age↗

PubMed1996

Scoliosis elasticity assessed by manual traction: 49 juvenile and adolescent idiopathic cases.

We assessed preoperative curve elasticity in 49 consecutive patients with juvenile or adolescent idiopathic scoliosis who were operated on with Harrington distraction rods. Preoperatively, the curve was determined from posteroanterior radiographs taken in the standing position and in the supine position, with traction. In the latter, the radiographs were taken at the moment of maximal traction when one technician applied traction to the ankles and another to the wrists. The scoliotic curve in the 10 patients with juvenile scoliosis averaged 59 degrees and 32 degrees in the standing and supine positions with traction, respectively. Immediately postoperatively, the curve averaged 19 degrees. 39 patients with adolescent scoliosis had a scoliotic curve which averaged 58 degrees in the standing position and 32 degrees in the supine position with traction. The mean postoperative measurement was 21 degrees. These findings suggest that manual traction is a simple and reliable means of predicting the minimal correction of the scoliotic curve to be expected, using Harrington distraction rods.

Adolescent↗

PubMed2003

Parasympathetic heart rate modulation during parabolic flights.

During parabolic flight short periods of microgravity and hypergravity are created. These changes influence cardiovascular function differently according to posture. During the 29th parabolic flight campaign of the European Space Agency (ESA), the electrocardiogram (ECG) was recorded continuously in seven healthy volunteers in two positions (standing and supine). Five different phases were differentiated: 1 g (1 g=9.81 m/s(2)) before and after each parabola, 1.8 g at the ascending leg of the parabola (hypergravity), 0 g at the apex, 1.6 g at the descending leg (hypergravity). We assessed heart rate variability (HRV) by indices of temporal analysis [mean RR interval (meanRR), the standard deviation of the intervals (SDRR), and the square root of the mean squared differences of successive intervals (rMSSD) and coefficient of variation (CV)]. In the supine position no significant differences were shown between different gravity phases for all HRV indices. In the standing position the 0 g phase showed a tendency towards higher values of meanRR compared to the control and to the other phases ( p=NS). SDRR, rMSSD and CV were significantly higher compared to control ( p<0.05). Significantly higher values for meanRR in the supine position at 1 g and hypergravity ( p<0.05) were found when compared to standing. SDRR was significantly higher at 0 g in the standing position compared to supine [95 (44) ms vs. 50 (15) ms; p<0.05] and lower in other phases. rMSSD and CV showed the same trend ( p=NS). We confirm that, during parabolic flights, position matters for cardiovascular measurements. Time domain indices of HRV during different gravity phases showed: (1) higher vagal modulation of the autonomic nervous system in microgravity, when compared with normo- or hypergravity in standing subjects; and (2) no differences in supine subjects between different g phases.

Adaptation, Physiological↗

PubMed2004

Effects of sevoflurane, propofol and position changes on respiratory mechanics.

This study was designed to investigate the effects of propofol, sevoflurane and position changes on respiratory mechanics. Forty patients scheduled for thyroid surgery were divided randomly into two groups; those receiving sevoflurane (group S) (n=20), and those receiving TIVA propofol (group P) (n=22). Dynamic compliance (Cdyn), peak inspiratory pressure (PIP), and respiratory resistance (Rr) values were recorded with a VenTrak respiratory monitor (Novometrix Inc. USA) at three time instances. The first measurement was done immediately after the beginning of ventilation and before the inhalation agent was initiated (Induction). Second measurement was done after 5 minutes of thyroid position (Thyroid) (ventilation with 1 MAC sevoflurane concentration or propofol infusion at the rate of 6 mg/kg/h). The third measurement was performed 5 minutes after end of surgery in the supine position (Supine) Blood gases were measured at the three time instances. Respiratory mechanics did not change in the P group (51 +/- 13, 46 +/- 11, 48 +/- 10 mL/cmH2O) at Induction, Thyroid and Supine positions). In the S group, dynamic compliance measurements showed changes statistically significant in the supine position (52 +/- 6 mL/cmH2O)) when compared to Induction (47 +/- 9 mL/cmH2O) and Thyroid position (47 +/- 6 mL/cmH2O) measurements (p<0.05). When the groups were compared with each other, there was no significant difference whatsoever at all periods (p>0.05). His concluded that sevoflurane, propofol and position changes exhibit similar effects on respiratory mechanics and blood gases at described dose and concentration.

Adult↗

PubMedDate not supplied

Effect of body positions and splints in bioelectrical impedance analysis.

The objective of this study was to evaluate body composition as measured by bioelectric impedance analysis using splints and body positions differing from the standard supine position. Forty-three patients, randomized into two groups of different body positions, and 101 healthy volunteers were prospectively studied. Resistance and reactance of body tissues were measured by bioelectric impedance analysis. Body composition is described by a three-compartment model composed of body fat, body cell mass, and extra cellular mass. The patients were measured in the standard supine position and then randomized into two groups. They were then remeasured with the appropriate splinting device or position change. Volunteers were measured in the standard supine position and all four alternative positions. There was a statistically significant difference demonstrated in whole body resistance, whole body reactance, body cell mass, and the ratio of extracellular mass to body cell mass in some body positions. The percentage of change with different body positions and splints, when compared with the standard supine position, was generally below 2%, a clinically insignificant difference. We conclude that the reliability of resistance and reactance as measured by bioelectric impedance analysis is clinically valid using any of the tested body positions and/or splints. The three-compartment model may be a useful concept to measure body composition changes in both healthy and sick persons.

Body Composition↗

PubMed2000

The effect of pressure from the table top and patient position on pelvic organ location in patients with prostate cancer.

PURPOSE: To assess the impact of pressure from the table top and patient position on the relationship of the prostate, rectum, and bladder to the bony pelvis. METHODS AND MATERIALS: In 9 patients with prostate cancer (3 status postprostatectomy), computed tomography (CT) scans were obtained in four positions: supine with and without false table top under the buttocks, prone with and without false table top under the lower abdomen. In four patients, a fifth scan was obtained in the first position (supine with table top in place) to assess the impact of changes in bladder/rectal fullness over time. Urination and defecation were not permitted between scans. For each patient, the four (or five) CT scans were registered to each other. RESULTS: The anal canal and the rectum caudal to the coccyx shifted posteriorly in 7/9 patients when the support under the buttocks was removed in the supine position. When pressure from the table top was removed in the prone position, the anterior bladder extension increased. The superior rectum was adjacent to the prostate in all scans and the prostate/superior rectum/bladder generally moved together. Rectal fullness changed with time and rectal gas position was gravity-dependent and shifted with patient position. Bladder volume increased with time. Organs had shifted and/or changed fullness between the first and fifth scan obtained in the same patient position approximately 90 min apart, mostly due to increase in bladder volume. All patients found the supine position most comfortable. CONCLUSIONS: The bladder and rectal fullness vary with time, confounding the ability to attribute changes in organ location to positional factors. Pressure from the table top affects the relative location of pelvic organs and, in part, is responsible for changes previously attributed to position/gravity.

Aged↗

PubMed1990

Comparison of effects of upright versus supine body position and liquid versus solid bolus on esophageal pressures in normal humans.

New studies monitoring ambulatory esophageal pressures during food ingestion often compare results to normal values obtained from supine liquid swallows. We compared distal esophageal peristaltic and lower esophageal sphincter (LES) pressures in 15 normal subjects during six liquid swallows in the upright and supine positions, and six solid (small marshmallow) swallows in upright position. LES pressures were significantly (P less than 0.05) higher supine than upright but no differences were noted in LES pressure, relaxation, and duration of relaxation between upright solid and liquid swallows. Distal peristaltic wave velocities were faster upright than supine. Peristaltic wave amplitudes, durations, and DP/DT were significantly (P less than 0.05) greater in supine than in upright position. Atypical wave forms, defined as nontransmitted, simultaneous, and simultaneous/repetitive, increased in the upright position compared to supine (P less than 0.01), and during solid vs liquid swallows (P less than 0.05). These results indicate that body position substantially affects normal distal esophageal peristalsis and LES pressure and that "abnormal" wave forms occur more frequently during swallowing solids than liquids in the upright position. Conclusions regarding "abnormal" motility over prolonged periods and during food ingestion in patients should be tempered by these findings.

Adult↗

PubMed2003

Laboratory assessment of diurnal and nocturnal ocular perfusion pressures in humans.

We estimated diurnal and nocturnal levels of ocular perfusion pressure at rest in both young and older adults in a clinical sleep laboratory. Measurements of blood pressure and intraocular pressure (IOP) were obtained every 2 hours for 24 consecutive hours in 16 healthy young adults (ages 18-25 years) and 16 older adults (ages 47-74 years). In the 16-hour diurnal wake period, blood pressure and IOP were measured after a 5-minute sitting rest. In the 8-hour nocturnal period, measurements were taken with subjects in the supine position. Sitting and supine ocular perfusion pressures in the diurnal and nocturnal periods were calculated respectively based upon the blood pressure and IOP. Ocular perfusion pressure was found to be higher in the older group than in the younger group throughout the 24 hours. The peak of ocular perfusion pressure was in the nocturnal period for both groups. Within each subject group, the average nocturnal ocular perfusion pressure in the supine position was higher than the average diurnal ocular perfusion pressure in the sitting position. The diurnal-to-nocturnal increase of ocular perfusion pressure was larger in the older group than in the younger group.

Adolescent↗

PubMedDate not supplied

Cardiac performance at rest and during exercise in normal subjects.

Hemodynamic profiles at rest and during bicycle exercise are described in 50 normal male subjects. In nine of these, the hemodynamics at rest and during exercise in the supine position have been compared to those in the sitting position. In the supine position, the observed and derived hemodynamic parameters at rest and during exercise (mean +/- standard deviation) were: heart rate 77 +/- 11 vs 127 +/- 17 beats . min-1, brachial arterial mean pressure, 12.4 +/- 1.2 vs 15.0 +/- 1.6 kPa (93 +/- 9 vs 113 +/- 12 mmHg), pulmonary arterial mean pressure 1.9 +/- 0.5 vs 3.2 +/- 0.8 kPa (14 +/- 4 vs 24 +/- 6 mmHg), left ventricular end-diastolic pressure 1.2 +/- 0.4 vs 1.7 +/- 0.7 kPa (9 +/- 3 vs 13 +/- 5 mmHg), cardiac output 6.3 +/- 1.5 vs 12.0 +/- 3.0 1 . min-1, stroke volume 88 +/- 22 vs 95 +/- 23 cm3, and left ventricular stroke work 0.93 +/- 0.27 vs 1.26 +/- 0.34 J . beats-1. Comparison of hemodynamic data in the supine and sitting position showed that pulmonary capillary wedge pressure, left ventricular end-diastolic pressure, cardiac output, stroke volume, and left ventricular stroke work were lower and heart rate higher in the sitting position, while brachial arterial and pulmonary arterial mean pressures were similar in the two positions. During exercise, the absolute values of pulmonary capillary wedge pressure, left ventricular end-diastolic pressure and stroke volume were lower and heart rate higher in the sitting position, while cardiac output and left ventricular stroke work were similar in the two positions. Comparison of changes from rest to exercise in the supine and sitting postures revealed similar increases in heart rate, pulmonary capillary wedge pressure, left ventricular end-diastolic pressure, cardiac output, and stroke volume in the two positions.

Adult↗

PubMed2006

[Management of the upper airway in spontaneously breathing children. A challenge for the anaesthetist].

In unconscious, spontaneously breathing and anaesthetised children, a high incidence of partial or complete airway obstruction jeopardizes sufficient oxygenation. In this situation, the most important and efficient manoeuvre is to open up the upper airway. Chin lift, jaw thrust and continuous positive airway pressure (CPAP) are proven and effective methods for opening an obstructed upper airway. In addition to these simple airway manoeuvres, different techniques of body positioning (e.g., lateral positioning or supine position in combination with the "sniffing position") are effective to improve and maintain upper airway patency.

Airway Obstruction↗

PubMed2004

Swimmer's CT: improved imaging of the lower neck and thoracic inlet.

CT findings of the base of the neck are often degraded by beam-hardening artifact from the shoulder girdle. This artifact can be reduced by placing the patient in a "swimmer's" position, a supine position in which the patient has one arm fully abducted and the other arm lowered. We selectively employed swimmer's CT in patients between January 1999 and December 2002 when standard (arms-down) CT failed to depict suspected disease. In nine of 10 patients, swimmer's CT improved CT quality or accuracy or both over that obtained when the standard CT position was used.

Artifacts↗

PubMed1998

Visualization of pressure-dependent luxury perfusion in a patient with subacute cerebral infarction.

Luxury perfusion characterized by depressed metabolism compared with CBF might be changed by decreasing cerebral perfusion pressure during the sitting position. A 77-yr-old man with subacute cerebral infarction was studied with brain X-ray computed tomography (CT), raise-up test with 99mTc-d,1-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission tomography (SPECT) and positron emission tomography (PET). Brain X-ray CT revealed a low-density area in the left middle cerebral artery (MCA) anterior area. Raise-up 99mTc-HMPAO brain SPECT revealed decreased uptake in the left MCA anterior area in the sitting position and subsequent supine 99mTc-HMPAO brain SPECT revealed hot accumulation there. PET study in the supine position demonstrated some differences between CBF and the cerebral metabolic rate for oxygen in the left MCA anterior area, indicating luxury perfusion. CBF in the area of luxury perfusion might be decreased during the sitting or standing position and increased during the supine position by dysautoregulation of the cerebral vessels in the luxury perfusion during the subacute infarct.

Aged↗