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Biomedical subjects

A Benini

Publications and source records attributed to A Benini.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effects of continuous negative extrathoracic pressure versus positive end-expiratory pressure in acute lung injury patients.

OBJECTIVE: To compare the effects of continuous negative extrathoracic pressure (CNEP) and positive end-expiratory pressure (PEEP) at the same level of transpulmonary pressure. DESIGN: Prospective analysis. SETTING: Medical intensive care unit of a university hospital. PATIENTS: Nine consecutive acute lung injury patients. Patients with cardiac failure and patients with chronic lung disease were excluded from the investigation. INTERVENTIONS: The patients were sedated and paralyzed while receiving mechanical ventilation and were studied in three different conditions: a) using a PEEP of 0 cm H2O (zero end-expiratory pressure); b) using a PEEP of 15 cm H2O; c) using CNEP. CNEP was applied to the thorax and the upper abdomen and its level was chosen to obtain a transpulmonary pressure similar to the one observed at a PEEP of 15 cm H2O. All patients had an arterial catheter, a pulmonary artery catheter, and a thermistor-tip fiberoptic catheter for thermo-dye-dilution in the femoral artery. These catheters were connected to an integrated monitoring system. We also placed an esophageal catheter in each patient to detect esophageal pressure. MEASUREMENTS AND MAIN RESULTS: For each step, we assessed the hemodynamic variations by measuring intravascular pressures (via a pulmonary artery catheter), transmural pressures (computed by subtracting esophageal pressure from intravascular pressure), and blood volumes (derived from the technique of double indicator). The application of CNEP of -20+/-0.7 cm H2O produced a venous admixture and PaO2/FO2 improvement similar to that obtained with a PEEP of 15 cm H2O. This procedure is associated with a higher cardiac index (5.5+/-1.5 vs. 4.6+/-1.2 L/min/m2; p < .05) coupled with lower central venous pressure, pulmonary artery occlusion pressure, and higher transmural pressures and blood volume parameters. CONCLUSIONS: In acute lung injury patients, a CNEP of -20 cm H2O has the capability to obtain transpulmonary pressure and lung function improvement similar to a PEEP of 15 cm H2O. CNEP differs from the positive pressure by increasing the venous return and the preload of the heart, and has no negative effects on cardiac performance.

APACHE↗
PubMed1998

Lumbar spine: quantitative and qualitative assessment of positional (upright flexion and extension) MR imaging and myelography.

PURPOSE: To compare measurements of the sagittal diameter of the lumbar dural sac obtained at positional magnetic resonance (MR) imaging and at functional myelography and to assess the influence of various body positions on the dural sac and the intervertebral foramina. MATERIALS AND METHODS: Thirty consecutive patients referred for lumbar myelography were examined with an open 0.5-T MR imager, Sagittal T2-weighted fast spin-echo images were acquired with patients in the supine, upright flexion, and upright extension positions. The midsagittal diameter of the dural sac was measured at the level of the disks on MR images and myelograms. Foraminal sizes on the MR images were scored independently by two observers. RESULTS: Correlation between MR imaging and myelographic measurements was high (r = .81-.97). A small but statistically significant positional dependence of the dural sac diameter was found in the lower lumbar spine. Position-dependent differences in foraminal scores were uncommon. CONCLUSION: Quantitative assessment of sagittal dural sac diameters is comparable between lumbar myelography and positional MR imaging. In a selected patient population, only small changes in the sagittal diameter of the dural sac and foraminal size can be expected between various body positions, and the information gained in addition to that from standard MR imaging is limited [corrected].

Adult↗
PubMed1998

Clinical assessment of a novel antiadhesion barrier gel: prospective, randomized, multicenter, clinical trial of ADCON-L to inhibit postoperative peridural fibrosis and related symptoms after lumbar discectomy.

A prospective, multicenter, randomized, double-blind, controlled study of ADCON-L Anti-Adhesion Barrier Gel (a medical device by Gliatech Inc, Cleveland, OH) was conducted in 298 patients undergoing first-time lumbar discectomy to evaluate the safety and effectiveness of ADCON-L in preventing postoperative peridural fibrosis and in improving patient clinical outcome. After lumbar discectomy, patients were randomized to receive either ADCON-L gel or nothing (control group) at the conclusion of the surgical procedure. Six months after surgery, peridural scar was evaluated by magnetic resonance imaging, and postoperative pain and straight-leg-raise angle were assessed. No statistically significant differences between the ADCON-L and control groups were observed in terms of adverse events or wound healing characteristics. ADCON-L gel was shown to be safe and to significantly inhibit peridural scar compared with the control group (P = 0.002). That peridural scarring was reduced with ADCON-L gel was further supported by direct visualization of scar tissue at reoperation in both groups. ADCON-L-treated patients had better clinical outcomes than did control patients. The incidence of activity-related pain was significantly reduced (P = 0.013), straight-leg-raise examination scores were significantly improved (P = 0.024 on the operative side and P = 0.015 on the nonoperative side), and ADCON-L reduced low back pain when it was most severe (P = 0.047) and at the end of the day (P = 0.044).

Adult↗
PubMed1997

[Cyst of the ligamentum flavum of the lumbar spine: description of 6 cases].

Cysts of the ligamentum flavum of the lumbar spine have seldom been described. They are clearly visible in computed tomography as well as nuclear magnetic resonance, but are frequently wrongly diagnosed as ganglion or synovial cysts. The correct diagnosis is not feasible until after surgery. Such space occupying lesions can most often lead to uniradicular pain due to compression of a root. These cysts should be viewed as part of the degenerative process of the spine but not as tumor lesions. They need to be removed only in case of root entrapment. On the basis of six of our cases treated by surgery we describe the symptoms, imaging findings, operative techniques and pathological investigations.

Aged↗
PubMed1996

[Spinal surgery in elderly patients].

Surgery of the degenerated cervical and lumbar spine in the elderly is often a very difficult challenge for the spine surgeon. General health, sociofamilial and mental condition the entire postoperative milieu of the patients as well as the surgical techniques and postoperative management are to be accurately evaluated and planned. The data on aging of populations in the near future highlights the importance of this aspect of geriatric medicine and surgery.

Aged↗
PubMed1996

[Cervical myelopathy: anatomopathology, clinical aspects and therapy].

Cervical myelopathy is a condition in which progressive compression of the spinal cord occurs going hand in hand with ongoing degenerative changes of the cervical segment of the spine. The degenerative changes start with a progressive degeneration of the disc, leading to a sometimes very severe narrowing of the cervical canal, mostly by osteophytes growing from the posterior edge of the vertebrae. Surgical decompression of the spinal cord is mandatory, as soon as the lesion is recognizable. In the same age group of patients with cervical myelopathy (i.e. aged between 50 and 70 years), primary degenerative lesions of the spinal cord, such as primary spastic progressive paralysis or amyotrophic lateral sclerosis, can occur. They resemble the cervical myelopathy closely. In that age group, everybody's cervical spine is degenerated to some degree; therefore, patients with primary and not compressive lesions of the spinal cord in the cervical tract are very often unnecessarily operated upon. Even if a pathognomonic neurologic pattern of cervical myelopathy does probably not exist, many of the more frequent symptoms and signs permit to lay out a profile of it, which may help to select the patients suitable for surgery as well as to avoid unnecessary and dangerous operations.

Aged↗
PubMed1996

Andreas Vesalius 1514-1564.

Andreas Vesalius was born in Brussels on December 31, 1514. After having spent some disappointing years at the Universities of Louvain and Paris, he graduated as Doctor of Medicine in Padua on December 5, 1537. The next day he was appointed as a teacher of both human anatomy and surgery. During the 6 years he held this chair, Vesalius engaged in impressive academic activities and published three masterly anatomic books: Tabulae Anatomicae Sex, De Humani Corporis Fabrica Libri Septem, and Epitome. The last two works contain anatomic woodcuts of incomparable artistic quality by Titian's pupils (by Stefan v. Calcar in particular). In 1544, at the age of 28, Vesalius gave up his chair and took up service as a court physician, first with Emperor Charles V and later with his son, Philip II of Spain. He died in 1564 on the small Greek island of Zante on return from a pilgrimage to the Holy Land. The gist of Vesalius' teaching was his conviction that valid anatomic knowledge could be gained only through dissection of the human corpse and not through the study of the traditional texts. Vesalius rid the study of human anatomy of mythic speculations, which had encrusted it for two millennia. Through Vesalius' work, human anatomy became an empirical science. Like Copernicus, Kepler, Bruno, and Galileo, Vesalius was one of the initiators of the new science. The tables of osteology and of the spine in Fabrica and Epitome are most impressive. Much of the nomenclature used for the spine today can be credited to him.

Anatomy↗
PubMed1996

[Micro-technological anterior discectomy without fusion in cervical disk displacement with radicular symptoms].

Only cervical disc herniation that provokes root compression unresponsive to conservative treatment should be selected for operation. The operative technique must allow adequate removal of the disc and relieve any root pressure without distressing the patient. Operative decompression of the root can be attained via laminectomy and arthrotomy or by way of an anterior approach. With this second procedure, the ventral discectomy can be done in conjunction with an interbody fusion. We report our experience with 216 patients who underwent anterior cervical microsurgical discectomy without fusion between 1980 and 1944. All these patients were suffering from compressive cervical radiculopathy caused by disc displacement without significant degenerative deformation of the motion segment and without manifest segmental instability. The follow-up ranged between 6 and 185 months (average 71 months) in the 175 patients in whom it was possible. Only in 7 patients (4%) is the result unsatisfactory; 79 patients (45%) are completely free of symptoms 99; (56.6%) are very satisfied and 45 (25.7%) satisfied with the result of the procedure.

Adult↗
PubMed1996

Pefloxacin penetration into human necrotic pancreatic tissue.

Antibiotic prophylaxis may be useful in acute necrotising pancreatis, a disease associated with a considerable incidence of infectious complications. The aim of this study was to assess pefloxacin penetration into necrotic pancreatic tissue during human necrotic pancreatitis. Ten patients (mean age 53.2 +/- 17.4 years) with severe acute pancreatitis (mean Ranson score 4.3) were studied. Pefloxacin was administered at a dose of 400 mg bd every 12 h by i.v. infusion (bolus, 15 min). Intraoperative samples of necrotic pancreatic tissue and blood were collected simultaneously 1, 2, 4.5, 6, 8.5 or 10 h after the last pefloxacin administration in patients treated for 1, 3, 4, 7, 8, 17 or 20 days. Drug concentrations were determined by the microbiological agar-well diffusion method (Escherichia coli Kp 05124 as test micro-organism in Isosensitest Agar). Levels in serum ranged from 2.0 to 9.0 mg/L (at 2 and 6 h, respectively), in necrotic pancreatic tissue from 2.0 to 29.0 micrograms/g depending on different sampling time. Maximum tissue peak concentrations appeared between 4 and 6 h. The necrotic pancreatic tissue/serum concentration ratio ranged from 0.9 to 5.1, values depending on tissue sample collection. Therapeutic concentrations (20.6 micrograms/g) above the MIC of potentially pathogenic enteric microorganisms were still present in necrotic pancreatic tissue 10 h after the last drug administration. Pefloxacin appeared to concentrate in necrotic pancreatic tissue, without appreciable accumulation after multiple-dose administration. The pefloxacin concentrations in necrotic pancreatic tissue showed high variability, depending on the degree of necrosis, inflammation and sample vascularization. Our results provided evidence of good, prompt penetration of pefloxacin into necrotic pancreatic tissue. Pefloxacin seems to exhibit favourable pharmacokinetic and pharmacodynamic properties for pancreatic infections.

Anti-Infective Agents↗
PubMed1996

Antimicrobial activity of human pancreatic juice and its interaction with antibiotics.

Pancreatic juice (PJ) should be a factor of variability in the antimicrobial activity of antibiotics eliminated by the pancreas during pancreatic infections. We studied its effects on the activity of antimicrobial drugs with different mechanisms of action. Samples of pure PJ were collected from 16 patients with stabilized external pancreatic fistulas. The antimicrobial activity of the juice at different concentrations (from 1.25 to 100%) alone and in combination with mezlocillin, imipenem, ceftriaxone, gentamicin, ofloxacin, and ciprofloxacin was studied by a microbiological method (continuous turbidimetric recording of bacterial growth). The human PJ showed dose-dependent antimicrobial activity that increased directly with the concentration. The activity of the antibiotics at bactericidal concentrations were not modified by the PJ, while the combination with subinhibitory concentrations produced the following variable and different effects: (i) additivity with mezlocillin, ceftriaxone, gentamicin, and ciprofloxacin and autonomy (no interaction) with imipenem and ofloxacin against Providencia rettgeri and (ii) additivity with ceftriaxone, ofloxacin, gentamicin, imipenem, and mezlocillin and autonomy with ciprofloxacin against Escherichia coli. In the presence of PJ, fluoroquinolones showed constant positive effects, while beta-lactams showed more variable antimicrobial activity. Antibiotic concentrations and PJ pharmacodynamics are the main factors determining the final effect of the interaction in vitro. These results may be useful in choosing antibiotics for the treatment of pancreatic infections when they are supplemented with the pharmacokinetic data for each drug.

Adult↗
PubMed1995

Vittorio Putti.

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History, 20th Century↗
PubMed1995

Surgical treatment of degenerative spondylolisthesis in the lumbar spine: no reposition without prior decompression.

In the present note, the cause of root compression in cases with degenerative lumbar spondylolisthesis is discussed in order to clarify the best method of surgery and to avoid iatrogenic damage of the cauda equina if a transpedicular fusion is going to be performed. The root compression is due to osteophytes growing out from the upper articular facets and from the upper ridge of the lamina of the lower vertebra. Therefore, the repositioning of the anteriorly displaced vertebra by the instrumentation could lead to the squeezing of the cauda equina between the withdrawn vertebral body and the degeneratively enlarged and hypertrophic facet joints of the lower vertebra. The reposition (even if incomplete) must always be preceded by decompression on both sides, even if radicular complaints are unilateral.

Cauda Equina↗