PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Prone Position”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,441 records · Page 80Linked to original sources

[Overdrainage in the treatment of hydrocephalus].

In infants or children, hydrocephalus is usually the consequence of an obstacle in the cerebro-spinal fluid (CSF) pathways and is most frequently treated by the insertion of a ventriculo-peritoneal shunt (rarely ventriculo-atrial). The CSF flow through such a shunt is equal to the ratio of the difference (DP) between the CSF input and output pressures over the valve resistance. When the child is in the upright position, a DP increase occurs due to the height of the hydrostatic column between the inlet and the shunt outlet. Thus if the shunt drains correctly in the prone position, it overdrains in the upright position. As the CSF flow through the shunt in standing patients is higher than the CSF secretion, the excess fluid will be taken out of the ventricles, resulting in pericerebral collections, slit ventricles or post-shunt craniostenoses. Many different techniques have been proposed to reduce overdrainage. The Orbis-Sigma shunt was designed in the "Service des Enfants-Malades" precisely for this purpose. In the upright position this shunt becomes a flow regulator and thus reduces overdrainage. Its use has decreased by 2-fold the number of mechanical complications related to overdrainage.

Cerebrospinal Fluid Shunts↗

Acute posterior cruciate ligament injuries.

One hundred and two posterior cruciate ligament injuries were reviewed (43 chronic and 59 acute repairs). The 59 acute repairs were profiled as to cause and site of injury, associated ligamentous damage, clinical examination, patient position at surgery, and reoperation rate. Twenty-two patients were followed up. Motor vehicle accidents and athletics were the usual causes of injury. In the 59 acute repairs, the posterior cruciate avulsion site was femoral in 21, midsubstance in 13, and tibial in 25. The high incidence of associated injuries included medial collateral ligament tears, capsular damage, lateral knee component damage, and anterior cruciate ligament ruptures. Thirteen of 59, believed to have isolated tears, had surgery in the prone position. Twelve were subsequently reoperated. Eight of 12 reoperations were done prone initially for an "isolated" tear. Our acute knees with poor results all had the most supposed "isolated" and midsubstance tears, and the most popliteal surgery. The posterior cruciate ligament tear is due to major violence with associated ligament injuries and has no single universal physical sign. Arthroscopy and examination under anesthesia are recommended to prevent the missed diagnosis (chronic case) or to clarify a suspected "isolated" tear prior to prone popliteal surgery.

Accidents, Traffic↗

CT prediction of irresectability in esophageal carcinoma: value of additional patient positions and relation to patient outcome.

BACKGROUND: To improve computed tomographic (CT) prediction of local irresectability and to correlate preoperative CT findings with patient outcome. METHODS: Eighty-five patients with esophageal carcinoma underwent CT in supine, left lateral decubitus, and prone positions. CT signs that were indicative of local irresectability included (1) an angle of contact >45 degrees with the aorta; (2) obliteration of triangular fat pad between the tumor, aorta, and spine; (3) tumor contiguous with the aorta in all three positions; and (4) indentation of the airway in all three positions. RESULTS: All CT signs indicative for local irresectability concerning the aorta had comparable percentages of false-positive scans (75%) when correlated with surgical findings. When correlated with pathologic findings, >45 degrees angle of contact with the aorta yielded the fewest false-positive cases (9%). Concerning the airway, additional positions changed the staging correctly in 1 of 18 cases. Median survival was 21 and 8 months, respectively, for tumors considered CT resectable or irresectable. CONCLUSION: Additional patient positions do not improve the CT prediction of aortic invasion. Predicted resectability correlates with a significant longer life expectancy.

Adenocarcinoma↗

Cot mattresses as reservoirs of potentially harmful bacteria and the sudden infant death syndrome.

Cot mattress materials were investigated as potential reservoirs of bacteria in relation to the sudden infant death syndrome (SIDS). The sleeping position of the infant significantly influenced bacterial population density of cot mattress polyurethane foams (p<0.0000001) and their covers (p<0.004). Staphylococcus aureus was isolated at significantly higher frequency (p<0.03) from the infant's head region of cot mattress materials. Significantly higher bacterial population densities (p<0.001) were associated with polyurethane foams from non-integral mattresses (exposed polyurethane foam), when compared to those from mattresses completely covered by polyvinyl chloride (integral type mattress). The frequency of isolation of S. aureus from polyurethane foams from non-integral mattresses was also significantly higher (p=0.03) than from foams from the integral type. The following factors were significantly associated with increased frequency of isolation of S. aureus: from the polyurethane foam, previous use of non-integral mattresses by another child (p=0.03 for all sample sites, p=0.01 for torso region); from the covers, sleeping in the prone position (p=0.003 head region, p=0.001 torso region). Prone sleeping was also significantly associated with increased bacterial population levels (p=0.01) and increased frequency of isolation of Escherichia coli (p=0.02) from the torso region of cot mattress covers. These findings could explain some recently identified risk factors for SIDS associated with type and previous use of cot mattresses. Clostridium perfringens was isolated at very low frequency and Streptococcus pyogenes was not isolated from any cot mattress materials tested.

Bedding and Linens↗

The early introduction of percutaneous renal biopsy in Italy.

BACKGROUND: Percutaneous renal biopsy, based on the use of an aspiration needle and the patient in the sitting position, was first described by Iversen and Brun in 1951. In 1954, Kark and Muehrcke described the use of the cutting Vim-Silverman needle on patients in the prone position, with a substantial improvement in the rate of success. The 1961 CIBA Foundation Symposium on renal biopsy marked the coming of age of this technique. During the 1950s in Italy, several individuals played a part in promoting and developing percutaneous renal biopsy. Because this pioneer work has received insufficient attention, we describe the contributions of Italians to the early introduction of this technique. METHODS: The Italian and international literature about percutaneous renal biopsy of the period 1951 through 1965 was reviewed. In addition, structured interviews with surviving members of the Italian researchers who first used renal biopsy were conducted. RESULTS: The first renal biopsies in Italy were performed in 1951 in Pisa by the group of Ernico Fiaschi (1913-1989). In their hands, renal biopsy became a tool to investigate the pathogenesis of renal diseases in particular, while simultaneously using the early application of immunofluorescence and electron microscopy. In 1954, Pietro Leonardi (1914-1991) and Arturo Ruol (born 1924) introduced renal biopsy in Padova; they used this technique extensively and published one of the first monographs on the subject. In 1957, Vittorio Bonomini (born 1928) introduced renal biopsy in Bologna, and in subsequent years used this technique to focus on the study of pyelonephritis. CONCLUSIONS: Our historical research shows that Italian groups were among the first to use and develop percutaneous renal biopsy both as a clinical tool and an investigative tool. This article gives international credit to their work.

Biopsy, Needle↗

EMG analysis of shoulder positioning in testing and strengthening the supraspinatus.

We examined the electromyographic (EMG) activity of the supraspinatus and other rotator cuff muscles, the three portions of the deltoid muscle, and the pectoralis major muscle in two previously suggested positions for isolating the supraspinatus. The position suggested by Jobe and colleagues is with the elbow extended, the shoulder in full internal rotation, and the arm in the scapular plane. Blackburn and colleagues recommended the prone position, with the elbow extended and the arm abducted to 100 degrees and externally rotated. Fine-wire EMG activity was obtained from the rotator cuff muscles and surface EMG from the other muscles in 17 subjects tested in these two positions. Both positions resulted in significant activity of the supraspinatus, but the difference between these two positions was not statistically significant. The Jobe position produced greater activation of the anterior deltoid and pectoralis major, whereas the Blackburn position caused greater activation of the posterior deltoid. Both positions produced significant activation of the middle deltoid. We conclude that either position can be used to strengthen the supraspinatus; however, neither position selectively isolates the supraspinatus during manual muscle testing.

Adult↗

A retrospective analysis of spontaneous sphenoid sinus fistula: MR and CT findings.

BACKGROUND AND PURPOSE: The sphenoid sinus is rarely implicated as a site of spontaneous CSF fistula. We undertook this study to evaluate the potential etiopathogenesis of spontaneous CSF fistula involving the sphenoid sinus and to review the imaging findings. METHODS: We retrospectively reviewed the imaging findings of 145 cases of CSF fistula from our departmental archives (August 1995 through August 1998). Fifteen (10%) patients had CSF fistulas involving the sphenoid sinus. Eleven (7%) patients had spontaneous CSF fistulas, whereas in four patients, the CSF fistulas in the sphenoid sinus were related to trauma. Of the 11 patients, nine underwent only plain high-resolution CT and MR cisternography. One patient additionally underwent contrast-enhanced CT cisternography, and one other patient underwent MR cisternography only. For each patient, the CSF fistula site was surgically confirmed. The MR imaging technique included T1-weighted and fast spin-echo T2-weighted 3-mm-thick coronal sequences obtained with the patient in the supine position. The plain high-resolution CT study included 3-mm-thick, and sometimes 1- to 1.5-mm-thick, coronal sections obtained with the patient in the prone position. Similar sections were obtained after injecting nonionic contrast material intrathecally via lumbar puncture for the CT cisternographic study. We evaluated each of the 11 patients for the exact site of CSF leak in the sphenoid sinus. We also determined the presence of pneumatization of lateral recess of the sphenoid sinus, orientation of the lateral wall of the sphenoid sinus, presence of arachnoid pits, presence of brain tissue herniation, and presence of empty sella in each of these patients. RESULTS: The exact sites of the CSF fistulas were documented for all 11 patients by using plain high-resolution CT, MR cisternography, or CT cisternography. In nine (82%) patients, the sites of the CSF fistulas were at the junction of the anterior portion of the lateral wall of the sphenoid sinus and the floor of the middle cranial fossa. In the remaining two (18%) patients, the sites of the CSF fistulas were along the midportion of the lateral wall of the sphenoid sinus. Of these 11 patients, one had bilateral sites of the CSF fistula at the junction of the anterior portion of the lateral wall of the sphenoid sinus with the floor of the middle cranial fossa. In nine (82%) patients, the presence of brain tissue herniation was revealed, and this finding was best shown by MR cisternography. Ten (91%) patients had extensive pneumatization of the lateral recess of the sphenoid sinus, with an equal number having outward concave orientation of the inferior portion of the lateral wall of the sphenoid sinus. In seven (63%) patients, the presence of arachnoid pits, predominantly along the anteromedial aspect of the middle cranial fossa, was shown. In seven (63%) patients, empty sella was shown. For comparison, we reviewed the CT studies of the paranasal sinuses in 100 age-matched control subjects from a normal population. Twenty-three had extensive lateral pneumatization of the sphenoid sinus along with outward concavity of the inferior portion of the lateral wall. None of these 23 patients had arachnoid pits. CONCLUSION: The sphenoid sinus, when implicated as a site of spontaneous CSF leak, yields a multitude of imaging findings. These are extensive pneumatization of the lateral recess of the sphenoid sinus, outward concave orientation of the inferior portion of the lateral wall of the sphenoid sinus, arachnoid pits, and empty sella. Considering the normative data, we speculate that this constellation of findings could play a role in the etiopathogenesis of spontaneous sphenoid sinus fistulas. Our findings also show the efficacy of noninvasive imaging techniques, such as plain high-resolution CT and MR cisternography, in the evaluation of sphenoid sinus CSF leak. Our data also suggest that spontaneous sphenoid sinus CSF leak is not an uncommon occurrenc

Adult↗

Postural displacement of the brain: feasibility of using CT for determination of stereotaxic coordinates.

Ten patients were studied with computed tomography (CT) in an attempt to determine if CT could be used preoperatively to establish stereotaxic coordinates for an operation and to find out more about how postural changes affect the position of the brain. Certain well defined cerebral structures were chosen as anatomic landmarks, and their relation to the skull determined with the patient in the supine, lateral, and prone positions. An external helmet fixation system was used to ensure consistent and reproducible CT slices. No displacement of the brain structures was observed in any of the positions, so it may be assumed that it is feasible to use CT-generated preoperative stereotaxic coordinates for reference during an operation, regardless of the patient's position. Four of the 10 patients were examined after lumbar intrathecal administration of metrizamide (200 mg I/ml). This small amount of positive contrast material did not seem to influence the position of the brain.

Brain↗

[Comparative studies of patient positioning for lumbar intervertebral disk operation].

For surgery on lumbar disks by the posterior route, patients are placed either on a Wilson frame or in genupectoral position. The aim of the prospective study was to record and describe the haemodynamic changes resulting from the patients' position. After written informed consent had been received, 80 neurosurgical patients undergoing lumbar disk surgery were randomly divided into two groups; group I--Wilson frame, group II--genupectoral position. In each group, 20 patients received total intravenous anaesthesia (Alfentanil or Remifentanil, Propofol) and 20 balanced anaesthesia with Isoflurane and Alfentanil or Remifentanil. Haemodynamic parameters (mean arterial pressure--MAP and heart rate--HR) were recorded automatically at three measuring times (MT): firstly, after induction of anaesthesia; secondly, before re-direction; thirdly, after re-direction on the Wilson frame or in the genupectoral position. Induction of anaesthesia did not lead to a significant decrease in MAP (MT 1: 92.5 +/- 15.2 mmHg, MT 2: 89 +/- 13.4 mmHg, n = 80). In group I (n = 40), no significant changes were observed in MAP and HR at MT 3 (p = 0.882, p = 0.051). In comparison to group I, the genupectoral position was associated with significant drops in MAP and HR. The genupectoral position caused a significant decrease in MAP (p < 0.001) and HR (p = 0.016) at MT 3. Our data suggest that body weight or body mass index do not necessarily lead to a preference for one of the two possible positions of the patient. Complications resulting from haemodynamic changes were not seen in either group. We recommend the Wilson frame for neurosurgical lumbar disk surgery in cases of cardiovascular or cerebrovascular disorders. The adaptive capacities in the genupectoral position as a result of the modifying distribution of blood volume are limited in these patients. Furthermore, the dose-dependent effects of different anaesthetics on haemodynamic parameters in these prone positions should be explored.

Adult↗

Enhanced alveolar clearance with chest percussion therapy and positional changes during whole-lung lavage for alveolar proteinosis.

Pulmonary alveolar proteinosis has traditionally been treated with whole-lung lavage (WLL). The literature describes a variety of techniques used in performing the WLL, including mechanical vs manual chest percussion, use of prone positioning, and variances in lavage volume. We have quantified and compared the effective alveolar clearance for each component of the lavage by measuring the dry weight of material in the lavage effluent. We measured this in five patients who underwent six consecutive WLLs at the University of Pittsburgh Medical Center. We performed the lavage in the following three stages: stage I, passive drainage; stage II, assisted clearance; and stage III, positional clearance. Aliquots of lavage effluent were centrifuged to determine the dry weight of material present in sequentially recorded bottles within each stage. At the initiation of each augmentation, there was a statistically significant improvement in the clearance of material (stage II, p = 0.009; stage III, p = 0.012). Furthermore, we show that lipoproteinaceous material is present in the lavage effluent in all stages of latter portions of the lavage. The effective removal of material would be expected to have an impact on the physiologic and clinical response to WLL. This finding emphasizes the importance of performing an adequate and standardized lavage.

Bronchoalveolar Lavage↗

A comparison of the lateral and posterior retroperitoneoscopic approach for complete and partial nephroureterectomy in children.

OBJECTIVE: To report the comparative results of a selective posterior or lateral retroperitoneoscopic approach (RPA) for nephroureterectomy in children. PATIENTS AND METHODS: Following an established experience with RPA, 36 complete and 19 partial nephrouretectomies were prospectively randomized to a posterior and lateral retroperitoneoscopic approach The patients were aged 4 months to 14 years, with a body weight at operation of 5.7-82 kg. For posterior RPA the child is positioned prone, with three access ports. The operating space was created with balloon dissection and maintained with CO2 insufflation. The child was then rotated 30 degrees with the kidney in the dependent position, and the operator and assistant standing on the affected side. In the lateral approach the child is in the lateral decubitus position with the operator and assistant facing the dorsal aspect of the patient. RESULTS: There was no significant difference in operative duration between the lateral and posterior approaches for nephrectomy (65 and 47 min) or partial nephrectomy (85 and 75 min). Two lateral nephrectomies required open conversion (one upper pole and one lower pole). CONCLUSION: The posterior approach gives easy and quick access to the renal pedicle. It is preferable for complete nephrectomy alone and partial or polar excision. In children under 5 years old a near complete ureterectomy can be achieved. The lateral approach creates more inferomedial space, gives better access to ectopic kidneys and allows complete ureterectomy in all cases. Access to the pedicle in the normal position requires more frequent positioning of the kidney. Care must be taken as peritoneal tears are more common.

Adolescent↗

Total removal of a falcotentorial junction meningioma by biparietooccipital craniotomy in the sea lion position: a case report.

The successful total removal of a huge falcotentorial junction meningioma in a 59-year-old woman by biparietooccipital craniotomy with the patient in the sea lion position (prone with a hyperextended neck and with 20 degrees elevation of the upper and lower halves of the body) is reported, with some comments on the advantages of this approach and position. Taking advantage of the exposure of the dural sinus, the confluens sinuum pressure was measured by direct catheterization with the patient in various positions. The pressure was 3.6 cm H2O in the sea lion position, 2.4 cm H2O in the reverse jackknife position (supine with 20 degrees elevation of the upper and lower halves of the body), and -12 cm H2O in the sitting position.

Adult↗

[Stress deformations of skeletal remains from prehistoric cremation burials].

Vertebrae and parts of joints from long bones from prehistoric cremations of the Late Bronze Age and Early Iron Age are presented, showing marked deformations caused by pressure during cremation when bones exposed to temperatures of 400 degrees-500 degrees Centigrade display minimal hardness. The vertebrae with deformation of the arcus parts are only from the lower vertebral column; on account of the weight of this body region, this suggests that the corpse lay in the dorsal position at the place of cremation. The fact that there were deformed arches only on one side might suggest an irregular structure of the surface on which the corpse lay. In the prone position, i.e. in the absence of pressure caused by body weight, all vertebrae should be unaltered; alternatively, if cremation wood was piled on top of the corpse, the arches of thoracic and cervical vertebrae are also likely to be deformed. Deformations resulting from weight bearing were found in the joints of extremities only, with flattening of the heads of joints as well as fissures in the external layers of bones and compression into folds. Some bones show distinct even grooves caused by direct pressure, possibly resulting from the fixation of joint regions for cremation? Evidently the deformations caused by the weighting down of different skeletal regions provide hints that may help in the recognition of cremation rites. It would be helpful if experimental cremations could be performed to establish the pressure necessary to cause deformations.

Biomechanical Phenomena↗

[Management of acute respiratory distress syndrome in Midi-Pyrnees].

OBJECTIVE: To assess management of acute respiratory distress syndrome (ARDS) in Midi-Pyrénées, France. METHODS: A prospective study using a questionnaire divided into 10 parts, definition, etiology, radiography, computed tomography, management, was conducted in 26 intensive care units in the Midi-Pyrénées. Management of ARDS in Midi-Pyrénées was comparted with management elsewhere as described in the literature. RESULTS: Overall participation rate was 73%. Disparities were found concerning the definition. Four etiologies accounted for 75% of all ARDS cases. Chest x-rays were used for positive diagnosis and thoracic scans for complications. Ventilatory and hemodynamic optimizations were the first line therapy used. Twenty-nine percent and 41% of the intensive care unites used nitric oxide and prone position respectively. CONCLUSIONS: There are differences between ARDS management in Midi-Pyrénées and that described in the current literature. Epidemiologic studies such as this one are necessary before publishing guidelines for the management of ARDS.

Diagnosis, Differential↗

[Evidence-based medicine of the acute respiratory distress syndrome].

Different therapeutic approaches have recently been developed for treatment of acute respiratory distress syndrome (ARDS) with the aim of improving the outcome. The clinical significance and success of these therapies is variable with respect to evidence based medicine. Lung protective ventilation is accepted as a proven therapy and the use of positive end-expiratory pressure as well as spontaneous breathing during controlled ventilation are common therapies. High frequency ventilation, partial liquid ventilation and pulmonary surfactant application are still in the experimental stage. The prone position is recommended for severe cases of ARDS and the application of inhaled nitric oxide and of extracorporeal membrane oxygenation is established in specialized centers for patients with imminent hypoxia. But for the routine use of these three therapies a clear improvement in outcome could not demonstrated. Recommended drug therapy is limited to the administration of stress doses of corticosteroids and a special anti-inflammatory enteral diet.

Evidence-Based Medicine↗

Effect of posture on inter-regional distribution of pulmonary ventilation in man.

Regional ventilation per unit alveolar volume (V/VA) and regional lung expansion (FRCR/TLCR) were measured in twelve normal male human subjects in seated, supine, lateral decubitus and prone postures using a gamma camera and inhalation of the radioactive gases 81Krm (half-life 13 sec) and 85Krm (half-life 4.4 h). FRCR/TLCR decreased from superior to inferior in all postures except prone where it was uniform; V/VA increased from superior to inferior except in the prone position where it was uniform. In the horizontal axis FRCR/TLCR and V/VA were uniformly distributed except for cranial to caudal gradients (with lower values caudally) in supine and lateral decubitus postures. In the prone posture V/VA tended to be higher in caudal lung zones.

Adult↗

Factors affecting heart rate variability and heart rate responses to tilting in infants aged 1 and 3 months.

Heart rate variability (HRV) and heart rate (HR) responses following a 60 degree head-up tilt were measured in 60 infants at 1 and 3 mo of age to investigate the effects on these of age, sleep state, sleep position, and mother's smoking status. HRV was determined from Poincaré plots of 500 sequential RR intervals to measure overall variability derived from the SDRR of this plot, and instantaneous variability derived from the SDdeltaRR. HR responses to the tilt were measured as changes in RR interval length from rest to immediately following the tilt and again once a stable pattern was reached. SDRR and SDdeltaRR increased 20 and 40%, respectively, with age (p < 0.0001), SDRR was higher in active sleep (AS) than quiet sleep (QS, +72%, p < 0.0001) but both measures of variability (SDRR and SDdeltaRR) were lower in the prone position compared with supine (-18%, p < 0.0001). However, several findings were dependent on the basal RR interval, thus the age effect disappeared once RR interval was taken into account, sleep state remained an important factor and the lower variability when prone now became a difference of -3% (p = 0.034). The tilt generally provoked a reflex tachycardia followed by a bradycardia and settling to a stable HR level below, at, or above baseline within 30 s. The more unusual responses were no HR change, sustained tachycardia or sustained bradycardia (15% of total). These were more likely to occur in younger infants (p = 0.008) and in AS (p < 0.0001). No changes were seen in any of the cardiac indices related to maternal smoking status. The findings confirm several reports indicating that prone sleeping damps some physiologic responses. The data emphasize the need to consider basal heart rate, and sleep position as well as sleep state in autonomic function testing during infant sleep.

Female↗