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At least 1,315 records · Page 73Linked to original sources

PubMed1989

Optimal coverage of peritoneal surface in whole abdominal radiation for ovarian neoplasms.

Patterns of failure in ovarian carcinoma include early seeding of the entire peritoneal cavity. Inability to encompass the anatomic extent of the peritoneal cavity is a possible factor leading to relapse. However, little has been published regarding technical advances in optimal coverage of the peritoneal surface in whole abdominal radiation. In the Department of Radiation Oncology at the University of Michigan, 21 consecutive patients were analyzed prospectively in regard to adequate coverage of peritoneum in the treatment of advanced ovarian carcinoma. Simulation and focused blocks were designed to treat the whole abdomen. CT treatment planning studies were obtained with the entire peritoneum identified as the target volume. Simulator designed blocks were projected over the CT scans throughout the treatment volume. Dose volume histograms were used to calculate the amount of target volume missed for each treatment plan. All treatment plans demonstrated different degrees of volume miss, ranging from 1 cm3 to 837.3 cm3 with a median of 137.9 cm3 overall. Volume missed directly correlated with increasing patient weight and flatter pelvic shape, but poorly with AP separation. This was especially evident for patients requiring treatment at extended distances in both the supine and prone positions. We conclude that bony landmarks are poor guidelines in designing pelvic blocks, especially in heavy patients and patients requiring treatment in both prone and supine positions. CT treatment planning is helpful to ensure optimal peritoneal coverage.

Abdomen↗

PubMed1986

Skin avulsion during oscillometry.

We observed a case of skin avulsion associated with measurement of blood pressure by oscillometry on an anesthetized patient in the prone position. Epidermal shearing may be avoided in the prone patient by either wrapping the antecubital skin underlying the blood pressure cuff with gauze or preventing weight-bearing by the cuffed portion of the arm.

Blood Pressure Determination↗

PubMed2004

Novel approaches in conventional mechanical ventilation for paediatric acute lung injury.

Acute lung injury remains a major cause of morbidity and mortality in paediatric intensive care units. Research over the past decade has altered our understanding of the pathophysiology of acute lung injury and the effects of mechanical ventilation on the lung. As a result, approaches to conventional mechanical ventilation of the injured lung are now largely centred around preservation of adequate gas exchange while protecting the lung from further ventilator-induced lung injury. Current techniques for accomplishing these goals include adjusting the ventilator based on the measurement and interpretation of pressure-volume curves, limitation of inspiratory tidal volumes, use of elevated levels of positive end-expiratory pressure, recruiting manoeuvres and prone positioning. The currently available data regarding the efficacy and appropriate use of these techniques are reviewed.

Child↗

PubMed2004

Why are aneurysms of the posterior inferior cerebellar artery so unique? Clinical experience and review of the literature.

BACKGROUND: Aneurysms of the posterior inferior cerebellar artery (PICA) are rare lesions. The anatomical behaviour of the artery itself is complex and characterised by a multitude of variations. The same holds true for the aneurysms discovered there. Dissecting aneurysms can be found from the PICA origin to the distal artery berry. They have a wider range of clinical and radiographical presentations and their surgical treatment requires more than one standard approach. METHODS: We encountered 14 patients with PICA aneurysms within two surgical series of a total of 1345 cerebral aneurysm patients (1 %). In this patient group of the last 27 years only 3 of the 14 were distal aneurysms ("true" PICA aneurysms) RESULTS: The 14 patients harboured 15 aneurysms (9 right-sided and 6 left-sided). The female/male ratio of the patients was 9/5, the mean age 52.7 years. 13 of them had sustained an SAH. 7/14 patients were hypertensive, in 10 patients at least one of putative cerebrovascular risk factors was found. From the 15 aneurysms treated, 11 were typical berry aneurysms, 4 dissecting aneurysms. The aneurysms ranged in size from 5 to 20 mm (mean 9.1). 11 aneurysms were located within the anterior medullary segment, 1 in the tonsillomedullary and 2 in the telovelomedullary segments. All patients were surgically treated, 10 in a semi-sitting position via a suboccipital craniotomy, 4 in the prone position. 13 aneurysms were clipped, two were treated differently. Two patients died due to their bad preoperative clinical status. CONCLUSIONS: The clinical, radiographical and surgical approaches to PICA aneurysms still represent a challenge.

Adult↗

PubMed1976

Changes in fetal and maternal heart rate during abdominal radiography in late pregnancy.

Continuous recordings of maternal and fetal heart rate were made in 30 antenatal patients during simulated abdominal radiography in late pregnancy. Transient changes in fetal heart rate occurred in 43 per cent of patients in the supine position compared with 27 per cent in the prone position. Transient increase of maternal heart rate occurred in 37 per cent of patients. There was no evidence of revealed or concealed caval occlusion.

Blood Pressure↗

PubMedDate not supplied

Evaluation of hamstring strength and tendon regrowth after harvesting for anterior cruciate ligament reconstruction.

BACKGROUND: It is generally thought that tissue regeneration and good functional recovery can be expected after anterior cruciate ligament reconstruction using the hamstring tendons. However, persistent strength deficit in deep knee flexion has also been reported. HYPOTHESIS: Morphologic regeneration of the harvested hamstring tendon is not necessarily associated with its functional recovery. STUDY DESIGN: Retrospective follow-up study. METHOD: Twenty-eight patients who underwent anterior cruciate ligament reconstruction with hamstring graft were evaluated after a minimum period of 2 years. Status of tendon regrowth was assessed by magnetic resonance imaging. To specifically analyze the functional deficit after graft harvest, the isometric hamstring strength was examined in a sitting position at 90 degrees of flexion and a prone position at 90 degrees and 110 degrees of flexion. Then, the strength data were correlated with the extent of tendon regeneration. RESULTS: In 22 of the 28 patients, a regrowth of the semitendinosus tendon was found, whereas regeneration of the gracilis tendon was observed in 13 patients. In the evaluation of hamstring strength, the isometric peak torque was reduced to 86.2%, 54.6%, and 49.1%, respectively, in the aforementioned 3 postures as compared with the contralateral side. CONCLUSIONS: Significant functional deficit of hamstring strength remains regardless of morphologic regeneration.

Adolescent↗

PubMed2001

[Role of videofluorography in the study of esophageal motility disorders].

PURPOSE: To repropose the importance of videofluoroscopy in the study of esophageal motor disorders, comparing the radiologic and manometric results; the manometric results are considered the reference parameters. MATERIAL AND METHODS: From 1996 to 1999, 76 patients (42 males and 34 females), were studied first using manometry and then videofluoroscopy. The patients had symptoms like dysphagia, thoracic pain or both. The manometric study was performed with a perfusional system equipped with 6 tips (4 radial for the study of the esophageal sphincters and 2 placed longitudinally for the study of the esophageal peristalsis). With the patient in a supine position we analysed 5-10 deglutitions with 5 ml water bolus at 20-25 degrees C, administered using a graduated syringe. The radiologic study was performed with a remote-control digital television system, connected to a video recorder. Three 7.5 ml bolues of high density barium suspension (250% weight/volume) were injected orally in the upright position and other three were injected in the prone position following the passage from the oral cavity to the stomach. RESULTS: The comparison of the manometric and videofluoroscopic results suggests that the total sensitivity of the radiological study in the detection of esophageal motor disorders was 92%. In particular dynamic radiologic investigation diagnosed the normal esophageal functionality in 100% of the cases, nonspecific esophageal motility disorders in 89.6%, diffuse esophageal spasm in 100% of the cases, the presence of achalasia in 90%, whereas "nutcraker esophagus" only in 50%. Videofluoroscopy therefore showed high sensitivity in four groups of the five considered. It has some limitations in the diagnosis of initial achalasia, and is not sufficiently sensitive in the diagnosis of "nutcracker esophagus". CONCLUSIONS: Videofluoroscopy is a simple method which presents high sensitivity and specificity in the detection of motility disorders of the esophagus and could therefore be proposed as the first diagnostic method in patients with specific symptoms.

Adult↗

PubMed2001

Recreational scuba divers' aversion to low-frequency underwater sound.

Increasing use of active low-frequency sonar by submarines and ships raises the risk of accidental exposure of recreational divers to low-frequency underwater sound (LFS). This study aimed to characterize the subjective responses of recreational scuba divers to LFS to ascertain the extent to which LFS may impact their enjoyment, comfort, or time spent underwater. Seventeen male and nine female recreational scuba divers participated. Diving was conducted in an acoustically transparent tank located within a larger anechoic pool. Subjects wore scuba gear and were positioned I m below the surface in a prone position. The sound transducer was located 4 m directly below the diver's head. Sound exposures consisted of three signal types (pure tone, 30 Hz hyperbolic sweep up, and 30 Hz hyperbolic sweep down) each presented at six center frequencies from 100 to 500 Hz and six sound pressure levels(SPL) ranging from 130 to 157 dB re 1 microPa. The duration of each sound exposure was 7 s. Subjects responded via an underwater console to rate aversion to LFS on a category-ratio scale, and to indicate the presence or absence of vibration of any body part. Aversion to LFS and the percent incidence of vibration increased as the SPL increased. The percent incidence of vibration decreased linearly with increasing frequency. At the highest SPL the probability that an aversion rating would exceed Very Severe (7 on the category-ratio scale) was predicted to be 19%. There was no significant difference in aversion among signal types. The 100 Hz frequency was the most aversive frequency (P < 0.05). A plot of aversion vs. frequency showed a U-shaped function with minimum aversion at 250 Hz. In conclusion, diver aversion to LFS is dependent upon SPL and center frequency. The highest aversion rating was given for 100 Hz, this frequency corresponded with the greatest probability of detecting vibration. Factors other than vibration seem to account for aversion to the highest frequencies. Our data suggest that LFS exposures up to 145 dB re 1 microPa at frequencies between 100 and 500 Hz will have minimal impact on the recreational diver.

Adult↗

PubMed1975

[Bilateral determination of 131-I-hippuran clearance in nephroptoses within the scope of sequential camera scintigraphy].

In 65 patients with uni- or bilateral nephroptosis the 131I-hippurate-clearance of each kidney was determined in combination with sequential gammacamera scintigraphy. The clearance values were normal in 65% without changing due to patient position. In 35% of the ptotic kidneys clearance values were lower than normal as well as in 17,5% of the nonptotic contralateral kidneys. 23% of the ptotic kidney showed diminished clearance values in the upright position, whereas a significant increase was found in prone position. Such short-time changes of the 131I-hippurate-clearance indicate diminished perfusion of the kidney when it is moving downward.

Adult↗

PubMed2007

Longterm treatment results of childhood medulloblastoma by craniospinal irradiation in supine position.

Medulloblastoma, a primitive neuroectodermal tumor growing in cerebellum, is one of the most sensitive to radiation therapy childhood brain tumors. The radiotherapy is an essential method of treatment for these tumours, but the surgery is the primary treatment of choice in medulloblastoma. I this study between January 1997 and March 2005 were post-operative irradiated a total number of 33 pediatric patients aged under 15 years (median age 8.7 years) with medulloblastoma. All tumors were histologically proved and were localizated infratentorially in the posterior fossa. All of the patients were irradiated with a dose of 24-36 Gy to the whole craniospinal axis and boost with conformal therapy restricted to the tumor bed to the total dose of 50-54 Gy (30-36 Gy "high risk", 24-30 Gy "standard risk" group). Chemotherapy received 26 patients (78%). Patients with craniospinal irradiation were placed in supine position and fixed by a vacuum-form body immobilizer and head mask. Irradiation was performed using standard fractionation (5 fractions per week) with a single dose of 1.5-1.8 Gy for craniospinal axis by photon beam (6 MV) of the linear accelerator. The median overall survival for the whole group was 55.3 months. The median of disease-free survival was 20.6 months, 8 patients (24%) died. In our study the statistical difference in survival rate between standard and high-risk patients with medulloblastoma was not shown. No relationship was found between survival and age, sex or tumor size. Endocrine deficits occurred in 45% (8 patients of the group were hypothyroid, 6 patients needed growth hormone replacement therapy, 1 patient had early puberty). This results (results of overall and disease-free survival) and side-effects of technique of craniospinal axis irradiation in supine position are comparable with results of technique in prone position. Further evaluation of the effectiveness of our therapy is not feasible due to the small number of patients.

Cerebellar Neoplasms↗

PubMed1990

Urography with spasmolytics.

The effects of glucagon (1 mg i.v.) and hyoscine butylbromide (Buscopan 20 mg i.v.) and placebo on the visualization of the pyelocalyceal systems and ureters was compared in a routine urography with abdominal compression in a double-blind, randomized trial comprising 189 kidneys and ureters. The visualization of the ureters in the supine position was highly significantly better than in the prone. In the prone position the ureteral visualization with Buscopan was marginally significantly better than with placebo or glucagon. Otherwise, neither Buscopan nor glucagon improved the pyeloureteral visualization. However, with glucagon the pyelocalyceal visualization was highly significantly poorer than with placebo, and marginally significantly poorer than with Buscopan.

Animals↗

PubMed1997

The effect of gravity on oesophageal peristalsis in humans.

Many mammalian species including non-human primates consume water in a body position not aided by gravity and it has been conjectured that oesophageal peristalsis overcomes gravity in humans. The purpose of this study was to determine the effects of gravity on oesophageal peristalsis in humans in response to water swallows. Six females (30-43 years old) and six males (27-46 years old) without oesophageal symptoms underwent oesophageal motility testing with intraluminal microtransducers placed 5, 7.5, 10 and 15 cm above the lower oesophageal sphincter. Subjects received ten 5 mL water swallows every 30 sec in the supine, standing, and head down (30 degrees) prone positions which were counterbalanced. Oesophageal contractile pressure (115, 98, 126 mmHg), duration (3.5, 3.0, 3.7 sec), onset velocity (4.7, 4.9, 4.7 cm sec-1), peak velocity (5.1, 4.8, 4.1 cm sec-1), average upstroke (dP/dT) (78, 75, 84 mmHg sec-1), or maximum upstroke (132, 120, 141 mmHg sec-1) were not significantly different among the head down prone, upright and supine positions, respectively. The frequency of abnormal contractile activity was statistically different among the positions. More abnormal contractions (i.e. simultaneous, retrograde, non-transmitted) occurred in the upright position (26%) when compared to either the supine (12%, P = 0.005) or head down prone (13%, P = 0.013) positions. The oesophagus tends to function normally to water swallows when unassisted by gravity. Oesophageal peristaltic dysfunction to water swallows may be more pronounced when assisted by the force of gravity.

Adult↗

PubMed2005

Clinical validation of high-resolution fast spin-echo MR colonography after colon distention with air.

To evaluate the feasibility of MR colonography (MRC) with air using two-dimensional (2D) T1-weighted fast spin-echo (T1wFSE) in patients scheduled for conventional colonoscopy (CC) after classic bowel preparation, and assess the ability of the technique to detect colonic lesions. The distention was sufficient for diagnosis, and the technique provided adequate delineation of the wall in the majority of segments. Residual fluid obscured the wall in different segments, especially in the ascending and descending colon (supine position) and in the cecum, transverse, and sigmoid colon (prone position). These findings were consistent with CT colonography. MRC visualized three lesions, missed one lesion >10 mm, visualized none of four lesions <5 mm, and yielded one false-positive lesion (5-10 mm). Missed lesions can be due to inconsistency in the slice positions between consecutive breath-holds, which is inherent to the multishot technique. Residual fluid may have obscured the smaller lesions. The shortcomings of the technique are limited coverage and signal drop-off at the borders of the field of view (FOV). Before multishot 2D T1wFSE colonography can become a valid screening method, improved patient preparation and a more practical technique are needed.

Adult↗

PubMed2002

Early renal changes in 45 degrees HDT rats.

BACKGROUND: Both microgravity and simulated microgravity models, such as the 45HDT (45 degrees head-down tilt), cause a redistribution of body fluids indicating a possible adaptive process to the microgravity stressor. Understanding the physiological processes that occur in microgravity is a first step to developing countermeasures to stop its harmful effects, i.e., (edema, motion sickness) during long-term space flights. HYPOTHESIS: Because of the kidneys' functional role in the regulation of fluid volume in the body, it plays a key role in the body's adaptation to microgravity. METHODS: Rats were injected intramuscularly with a radioactive tracer and then lightly anesthetized in order to facilitate their placement in the 45HDT position. They were then placed in the 45HDT position using a specially designed ramp (45HDT group) or prone position (control group) for an experimental time period of 1 h. During this period, the 99mTc-DTPA (technetium-labeled diethylenepentaacetate, MW=492 amu, physical half-life of 6.02 h) radioactive tracer clearance rate was determined by measuring gamma counts per minute. The kidneys were then fixed and sectioned for electron microscopy. A point counting method was used to quantitate intracellular spaces of the kidney proximal tubules. RESULTS: 45HDT animals show a significantly (p=0.0001) increased area in the interstitial space of the proximal tubules. CONCLUSIONS: There are significant changes in the kidneys during a 1 h exposure to a simulated microgravity environment that consist primarily of anatomical alterations in the kidney proximal tubules. The kidneys also appear to respond differently to the initial periods of head-down tilt.

Adaptation, Physiological↗

PubMed2003

Spinal anaesthesia for spinal surgery.

Spinal anaesthesia for spinal surgery is becoming increasingly more popular because this anaesthetic technique allows the patient to self-position and avoid neurological injury that may occur with prone positioning under general anaesthesia. Spinal anaesthesia reduces intraoperative surgical blood loss, improves perioperative haemodynamic stability and reduces pain in the immediate postoperative period. This leads to a reduced need for analgesics and a reduction in the incidence of nausea and vomiting in the postoperative setting. Spinal anaesthesia for lumbar spine surgery also decreases the incidence of lower extremity thrombo-embolic complications and does not increase the occurrence of problems with micturition. These benefits increase the patient's satisfaction, and they expedite discharge of the patient from the hospital. Combination anaesthetic techniques, using both subarachnoid and epidural dosing schemes, may be beneficial for improving postoperative pain control and add further to the benefit of spinal anaesthesia for lumbar spine surgical procedures.

Anesthesia, Spinal↗

PubMed2001

Pulmonary and extrapulmonary forms of acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is usually viewed as the functional and morphological expression of a similar underlying lung injury caused by a variety of insults. However, the distinction between ARDS due to a direct (ARDSp) versus an indirect (ARDSexp) lung injury is gaining more attention as a means of better comprehending the pathophysiology of ARDS and for modifying ventilatory management. From the few published studies, we can summarize that: (1) the prevalent damage in early stages of a direct insult is intra-alveolar, whereas in indirect injury it is the interstitial edema. It is possible that the two insults may coexist (i.e., one lung with direct injury (as in pneumonia) and the other with indirect injury, through mediator release from the contralateral pneumonia); (2) the radiological pattern, by chest x-ray or computed tomography (CT), is different in ARDSp (characterized by prominent consolidation) and ARDSexp (characterized by prominent ground-glass opacification); (3) in ARDSp lung elastance is more markedly increased than in ARDSexp, where the main abnormality is the increase in chest wall elastance, due to abnormally high intra-abdominal pressure; (4) positive end-expiratory pressure (PEEP), inspiratory recruitment, and prone position are more effective to improve respiratory mechanics, alveolar recruitment, and gas-exchange in ARDSexp. Further studies are warranted to better define if the distinction between ARDS of different origins can improve clinical management and survival.

Journal Article↗

PubMed1999

Extracorporeal life support in pulmonary failure after trauma.

OBJECTIVE: To present a series of 30 adult trauma patients who received extracorporeal life support (ECLS) for pulmonary failure and to retrospectively review variables related to their outcome. METHODS: In a Level I trauma center between 1989 and 1997, ECLS with continuous heparin anticoagulation was instituted in 30 injured patients older than 15 years. Indication was for an estimated mortality risk greater than 80%, defined by a PaO2: FIO2 ratio less than 100 on 100% FIO2, despite pressure-mode inverse ratio ventilation, optimal positive end-expiratory pressure, reasonable diuresis, transfusion, and prone positioning. Retrospective analysis included demographic information (age, gender, Injury Severity Score, injury mechanism), pulmonary physiologic and gas-exchange values (pre-ECLS ventilator days [VENT days], PaO2:FIO2 ratio, mixed venous oxygen saturation [SvO2], and blood gas), pre-ECLS cardiopulmonary resuscitation, complications of ECLS (bleeding, circuit problems, leukopenia, infection, pneumothorax, acute renal failure, and pressors on ECLS), and survival. RESULTS: The subjects were 26.3+/-2.1 years old (range, 15-59 years), 50% male, and had blunt injury in 83.3%. Pulmonary recovery sufficient to wean the patient from ECLS occurred in 17 patients (56.7%), and 50% survived to discharge. Fewer VENT days and more normal SvO2 were associated with survival. The presence of acute renal failure and the need for venoarterial support (venoarterial bypass) were more common in the patients who died. Bleeding complications (requiring intervention or additional transfusion) occurred in 58.6% of patients and were not associated with mortality. Early use of ECLS (VENT days < or = 5) was associated with an odds ratio of 7.2 for survival. Fewer VENT days was independently associated with survival in a logistic regression model (p = 0.029). Age, Injury Severity Score, and PaO2:FIO2 ratio were not related to outcome. CONCLUSION: ECLS has been safely used in adult trauma patients with multiple injuries and severe pulmonary failure. In our series, early implementation of ECLS was associated with improved survival. Although this may represent selection bias for less intractable forms of acute respiratory distress syndrome, it is our experience that early institution of ECLS may lead to improved oxygen delivery, diminished ventilator-induced lung injury, and improved survival.

Adolescent↗

PubMed1998

Transillumination mapping prior to ambulatory phlebectomy.

BACKGROUND: Ambulatory phlebectomy (AP) for removal of varicose and reticular veins has become a very popular and widely used in-office outpatient technique over the past decade. One of the major obstacles of this or any other surgical vein removal technique is the technical difficulty presented to the surgeon by the disappearance of the veins to be removed when the patient is positioned horizontally on an operative table. Preoperative marking is therefore essential. OBJECTIVE: To investigate whether use of transillumination would facilitate and enhance marking of varicose veins prior to AP, we performed a study in which both traditional marking with the patient standing and transillumination marking with the patient horizontal were performed sequentially. METHODS: One hundred patients were sequentially examined prior to AP. The veins to be removed were mapped by the traditional way utilizing visual inspection and palpation in a standing position. They were then mapped in the supine or prone position utilizing a transillumination device specifically designed to enhance visualization of veins prior to venipuncture. RESULTS: In 100 out of 100 patients the markings performed using transillumination mapping most closely correlated with actual vein position during surgery. In addition, transillumination allowed for gauging of vein depth. CONCLUSIONS: Transillumination mapping significantly enhances the technique of ambulatory phlebectomy by more accurately visualizing the course of a varicose vein prior to extraction. Furthermore, sites for incisions or punctures are more accurately guided. As a result of this experience, it is now our routine practice to perform preoperative mapping for AP by transillumination in the horizontal position.

Ambulatory Surgical Procedures↗