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Sylvain Palmer

Publications and source records attributed to Sylvain Palmer.

11 recordsLinked to original sources
PubMed2005

Brain tissue oxygenation in brain death.

INTRODUCTION: The value of brain tissue oxygenation (PbtO2) measurements in determining brain death is unknown. METHODS: Eleven of 72 patients who had brain tissue oxygen monitors placed experienced brain death. Admission diagnoses included six severe traumatic brain injuries, one multiple trauma with cardiac arrest, one brain tumor, one subarachnoid hemorrhage, one intracerebral hemorrhage, and one cerebral stroke. Eleven males and zero females were studied, with an average age of 26 years (range: 20-70 years). Nine patients had Glasgow Coma Scores (GCS) of 3 on admission, one patient had a GCS of 5, and one patient had a GCS of 15. RESULTS: Time from admission to declaration of brain death varied from 5 hours to 7 days; the most common interval was 1 or 2 days. Cerebral perfusion pressure (CPP) fell to 0 in eight patients, which indicated primary failure of cerebral perfusion. CPP stayed above 60 mmHg in three patients, indicating primary tissue failure, possibly of the cerebral microvasculature. PbtO2 fell to 0 in all patients who experienced brain death, and all patients with PbtO2 of 0 experienced brain death. None of the 61 patients who did not experience brain death had confirmed PbtO2 readings of 0. CONCLUSION: PbtO2 can be successfully and accurately used as a bedside adjunctive test for brain death. The use of PbtO2 as a sole confirmatory test for brain death in the setting of an appropriate clinical examination will require the evaluation of a larger number of patients to assess its sensitivity and specificity.

Adult↗
PubMed2004

Retrospective analysis and modifications of retractor systems for anterior odontoid screw fixation.

The authors present an in-depth retrospective analysis of retractor systems for anterior odontoid screw fixation. They discuss various modifications and innovations of such systems and describe their own tubular retractor system, in which a beveled end conformal to the ventral surface of the vertebral column at the C2-3 level is introduced together with an incorporated light source. This new retractor system allows optimal anatomical exposure for controlled odontoid screw placement with improved protection of surrounding vital structures.

Aged↗
PubMed2004

Minimally invasive surgical treatment of lumbar synovial cysts.

OBJECTIVE: Synovial cysts are a rare cause of lumbar radiculopathy and back pain. Surgical treatment is directed at complete excision of the cyst. We used minimally invasive surgical techniques for a series of patients, to assess the effectiveness of this approach for resection of synovial cysts. METHODS: Seventeen patients (10 female and 7 male patients) with presumed synovial cysts, as indicated on magnetic resonance imaging scans, underwent surgical resection with the 18-mm METRx tubular retractor system (Medtronic Sofamor Danek, Memphis, TN). A unilateral approach was used, with either an operating microscope (13 cases) or a magnifying endoscope (4 cases), depending on the preference of the surgeon. Outcomes were reported by using modified MacNab criteria. RESULTS: The average patient age was 64 years (range, 46-82 yr). The L4-L5 level was most commonly affected (82% of cases). Grade 1 spondylolisthesis at the level harboring the synovial cyst was observed for 47% of the patients; all cases of spondylolisthesis involved the L4-L5 level. The mean operative time was 97 minutes, and the average blood loss was 35 ml. Excellent or good results were achieved for 94% of the patients. A dural tear that did not violate the arachnoid membrane occurred during surgery for one patient but did not require further treatment. CONCLUSION: Synovial cysts can be effectively treated with a tubular retractor system in conjunction with an endoscope or microscope. Use of the tubular retractor minimizes soft-tissue trauma, incision length, blood loss, and disruption of ligamentous and bony structures. This may be particularly significant when synovial cysts are associated with spondylolisthesis, minimizing the risk of progressive instability and the need for fusion.

Aged↗
PubMed2002

Use of a tubular retractor system in microscopic lumbar discectomy: 1 year prospective results in 135 patients.

OBJECT: Application of minimally invasive techniques to lumbar disc surgery has led to the development of the Microscopic Endoscopic Tubular Retractor System (METRx-MD). A prospective evaluation of results and complications was undertaken. METHODS: One hundred thirty-five patients underwent surgery in which the METRx-MD system was used; most procedures were performed on an outpatient basis, and general anesthesia was induced in all cases. All patients were followed prospectively. Outcomes were measured using a visual analog scale (VAS), the Oswestry Disability Index (ODI), and the Short Form-36 (SF-36) questionnaires. Follow-up data were collected by an outside company, which also tabulated the data. Data were collected in 129 of 135 patients. Improvement was seen on the VAS (Scores 7-2), ODI (Scores 57-16), and SF-36 scales (bodily pain Scores 20-60). Patient satisfaction with results was 94% and with office services 88%. Thirty-six percent of patients returned to work at 0 to 2 weeks, 38% at 3 to 5 weeks, and 25% at 5 to 26 weeks. Hospital charges decreased by $2395 (18%). The mean operative time was 66 minutes, and the mean blood loss was 22 ml. Complications included one superficial wound infection, one discitis, three durotomies, and three cases of excessive bleeding (> 100 ml). There were five reoperations: four for recurrent disc herniations, (two ipsilateral and two contralateral to the index site) and one for spinal stenosis contralateral to the index site. CONCLUSIONS: Minimally invasive surgery in which the METRx-MD system is used is clinically effective and cost effective. Patient satisfaction was high. A mean per case cost savings of $2395 was realized. Complications rates were comparable with those associated with traditional microdiscectomy procedures.

Adult↗
PubMed2002

Bilateral decompressive surgery in lumbar spinal stenosis associated with spondylolisthesis: unilateral approach and use of a microscope and tubular retractor system.

OBJECT: The objective of this study was to assess the feasibility and efficacy of treating spondylolisthesis-related spinal stenosis via unilateral approach bilateral decompression in which METRx-MD instrumentation is placed. METHODS: Eight consecutive patients with spinal stenosis underwent bilateral decompressions via a unilateral approach in which METRx-MD instrumentation was placed. The procedures were performed on an outpatient basis after induction of general anesthesia. The patients underwent preoperative and 3-month postoperative plain radiography in which flexion-extension x-ray films were obtained. Preoperative and postoperative magnetic resonance imaging was also performed. All radiographs and neuroimages were read by a single radiologist blinded to the clinical results. Eight vertebral levels in the eight patients were surgically decompressed (in one patient an additional level of nonspondylolisthesis-related stenosis was decompressed). The mean operative time was 92 minutes and the mean blood loss was 33 ml/level. Preoperatively stenosis was severe in five patients, moderate/severe in two, and moderate in one; postoperatively stenosis was absent in five, mild in two, and mild/moderate in one. Motion was detected on flexion-extension radiographs in three patients, but on early (3-month) postoperative radiographs there was no evidence of progression. CONCLUSIONS: By following the authors' procedure, minimally invasive bilateral decompression of acquired spinal stenosis associated with spondylolisthesis can be successfully performed on an outpatient basis, with reasonable operative times, minimal blood loss, and acceptable morbidity.

Aged↗
PubMed2002

Bilateral decompression of lumbar spinal stenosis involving a unilateral approach with microscope and tubular retractor system.

OBJECT: The authors studied a consecutive series of patients with spinal stenosis in whom surgery was performed by a single surgeon who used a microscopic tubular retractor system (METRx-MD); patients underwent prospective evaluation involving radiography and magnetic resonance (MR) imaging. The objective was to assess the feasibility and surgery-related efficacy of performing unilateral-approach bilateral decompression and utilization of METRx-MD instrumentation in patients with spinal stenosis. METHODS: Seventeen consecutive patients with spinal stenosis underwent bilateral decompression; surgery was performed via a unilateral approach using METRx-MD instrumentation. The procedures were performed on an outpatient basis after induction of general anesthesia. Preoperative and 3-month follow-up plain radiographs with flexion-extension views were obtained. Preoperative and postoperative MR imaging was also performed. All studies were assessed by a single radiologist blinded to the clinical results. Twenty-two levels were surgically decompressed. The mean operative time was 90 minutes and the mean blood loss was 28 ml per level. Preoperatively stenosis was severe at 13 levels, moderate/severe at eight, and moderate at one. Postoperatively stenosis was absent at 13 levels, mild at seven, mild/moderate at one, and moderate at one. Preoperatively degenerative spondylolisthesis was documented in eight patients, with flexion-extension radiography revealing motion in three cases. On early (3-month) postoperative x-ray films there was no evidence of progression in any case. Grade I spondylolisthesis developed postoperatively in one patient, who remained asymptomatic. CONCLUSIONS: Minimally invasive bilateral decompression and instrumentation-assisted fusion can be successfully performed via a unilateral approach in patients with acquired spinal stenosis; the procedure can be undertaken on an outpatient basis, with reasonable operative times, minimal blood loss, and acceptable morbidity rates.

Adult↗
PubMed2002

Minimally invasive percutaneous posterior lumbar interbody fusion.

OBJECTIVE: The wide exposure required for a standard posterior lumbar interbody fusion (PLIF) can cause unnecessary trauma to the lumbar musculoligamentous complex. By combining existing microendoscopic, percutaneous instrumentation and interbody technologies, a novel, minimally invasive, percutaneous PLIF technique was developed to minimize such iatrogenic tissue injury (MIP-PLIF). METHODS: The MIP-PLIF technique was validated in three cadaveric torsos with six motion segments decompressed and fused. Preoperative variables measured from imaging included interpedicular distance, pedicular height and width, interspinous distance, lordosis, intervertebral height, Cobb angle, and foraminal height and volume. Using the METRx and MD spinal access systems (Medtronic Sofamor Danek, Memphis, TN), bilateral laminotomies were performed using a hybrid of microsurgical and microendoscopic techniques. The intervertebral disc spaces were then distracted and prepared with the Tangent (Medtronic Sofamor Danek) interbody instruments. Either a 10 or 12 by 22 mm interbody graft was then placed. Using the Sextant (Medtronic Sofamor Danek) system, percutaneous pedicle screw-rod fixation of the motion segment was completed. We then applied MIP-PLIF in three patients. RESULTS: For segments with preoperative intervertebral/foraminal height loss, MIP-PLIF was effective in restoring both heights in all cases. The amount of improvement (9.7 to 38% disc height increase; 7.7 to 29.9% foraminal height increase) varied directly with the size of the graft used and the original degree of disc and foraminal height loss. Segmental lordosis improved by 29% on average. Graft and screw placement was accurate in the cadavers, except for a single Grade 1 screw violation of one pedicle. The average operative time was 3.5 hours per level. In our three clinical cases, the MIP-PLIF procedure required a mean of 5.4 hours, estimated blood loss was 185 ml, and inpatient stay was 2.8 days, with no intravenous narcotic use after 2 days in any of the patients. All screw and graft placements were confirmed. CONCLUSION: A complete PLIF procedure can be safely and effectively performed using minimally invasive techniques, thereby potentially reducing the pain and morbidity associated with standard open surgery. Prospective, randomized outcome studies will be required to validate the efficacy of this exciting new surgical technique.

Aged↗
PubMedDate not supplied

Refractory increased intracranial pressure in severe traumatic brain injury: barbiturate coma and bispectral index monitoring.

Patients with severe traumatic brain injury resulting in increased intracranial pressure refractory to first-tier interventions challenge the critical care team. After exhausting these initial interventions, critical care practitioners may utilize barbiturate-induced coma in an attempt to reduce the intracranial pressure. Titrating appropriate levels of barbiturate is imperative. Underdosing the drug may fail to control the intracranial pressure, whereas overdosing may lead to untoward effects such as hypotension and cardiac compromise. Monitoring for a therapeutic level of barbiturate coma includes targeting drug levels and using continuous electroencephalogram monitoring, considered the gold standard. New technology, the Bispectral Index monitor, utilizes electroencephalogram principles to monitor the level of sedation and hypnosis in the critical care environment. This technology is now being considered for targeting appropriate levels of barbiturate coma.

Adult↗
PubMedDate not supplied

What's the "hyper" in hyperacute stroke? Strategies to improve outcomes in ischemic stroke patients presenting within 6 hours.

Ischemic stroke patients presenting to acute care hospitals require an organized response from multiple disciplines and clinical areas. Patients presenting within 6 hours of stroke onset constitute a category of stroke patient known as the "hyperacute stroke patient." This category of stroke patients is eligible for treatment using intravenous recombinant tissue plasminogen activator when treated within 3 hours, or interventional treatment options when treated within 6 hours of stroke onset. Guidelines have been established identifying critical elements for hospitals in order to be designated as primary or comprehensive stroke centers. Research studies exploring treatment options for stroke, as well as general care priorities exist in the scientific literature but must be integrated into hospital-based protocols. Recommended interventions are highlighted to assist critical care practitioners in the delivery of care for stroke patients. Coordinated teams using an evidence-based approach can optimize the outcomes of the stroke patient population.

Acute Disease↗