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Peter D LeRoux

Publications and source records attributed to Peter D LeRoux.

6 recordsLinked to original sources
PubMed2004

Cerebral oxygenation following decompressive hemicraniectomy for the treatment of refractory intracranial hypertension.

OBJECT: Medically intractable intracranial hypertension is a major cause of morbidity and mortality after severe brain injury. One potential treatment for intracranial hypertension is decompressive hemicraniectomy (DCH). Whether and when to use DCH, however, remain unclear. The authors therefore studied the effects of DCH on cerebral O2 to develop a better understanding of the effects of this treatment on the recovery from injury and disease. METHODS: The study focused on seven patients (mean age 30.6 +/- 9.7 years) admitted to the hospital after traumatic brain injury (five patients) or subarachnoid hemorrhage (two patients) as part of a prospective observational database at a Level I trauma center. At admission the Glasgow Coma Scale (GCS) score was 6 or less in all patients. Patients received continuous monitoring of intracranial pressure (ICP), cerebral perfusion pressure (CPP), blood pressure, and arterial O2 saturation. Cerebral oxygenation was measured using the commercially available Licox Brain Tissue Oxygen Monitoring System manufactured by Integra NeuroSciences. A DCH was performed when the patient's ICP remained elevated despite maximal medical management. CONCLUSIONS: All patients tolerated DCH without complications. Before the operation, the mean ICP was elevated in all patients (26 +/- 4 mm Hg), despite maximal medical management. After surgery, there was an immediate and sustained decrease in ICP (19 +/- 11 mm Hg) and an increase in CPP (81 +/- 17 mm Hg). Following DCH, cerebral oxygenation improved from a mean of 21.2 +/- 13.8 mm Hg to 45.5 +/- 25.4 mm Hg, a 114.8% increase. The change in brain tissue O2 and the change in ICP after DCH demonstrated only a modest relationship (r2 = 0.3). These results indicate that the use of DCH in the treatment of severe brain injury is associated with a significant improvement in brain O2.

Adult↗
PubMed2004

Relationship between intracranial pressure and other clinical variables in patients with aneurysmal subarachnoid hemorrhage.

OBJECT: Increased intracranial pressure (ICP) is well known to affect adversely patients with head injury. In contrast, the variables associated with ICP following aneurysmal subarachnoid hemorrhage (SAH) and their impact on outcome have been less intensely studied. METHODS: In this retrospective study the authors reviewed a prospective observational database cataloging the treatment details in 433 patients with SAH who had undergone surgical occlusion of an aneurysm as well as ICP monitoring. All 433 patients underwent postoperative ICP monitoring, whereas only 146 (33.7%) underwent both pre- and postoperative ICP monitoring. The mean maximal ICP was 24.9 +/- 17.3 mm Hg (mean +/- standard deviation). During their hospital stay, 234 patients (54%) had elevated ICP (> 20 mm Hg), including 136 of those (48.7%) with a good clinical grade (Hunt and Hess Grades I-III) and 98 (63.6%) of the 154 patients with a poor grade (Hunt and Hess Grades IV and V) on admission. An increased mean maximal ICP was associated with several admission variables: worse Hunt and Hess clinical grade (p < 0.0001), a lower Glasgow Coma Scale (GSC) motor score (p < 0.0001); worse SAH grade based on results of computerized tomography studies (p < 0.0001); intracerebral hemorrhage (p = 0.024); severity of intraventricular hemorrhage (p < 0.0001); and rebleeding (p = 0.0048). Both intraoperative cerebral swelling (p = 0.0017) and postoperative GCS score (p < 0.0001) were significantly associated with a raised ICP. Variables such as patient age, aneurysm size, symptomatic vasospasm, intraoperative aneurysm rupture, and secondary cerebral insults such as hypoxia were not associated with raised ICP. Increased ICP adversely affected outcome: 71.9% of patients with normal ICP demonstrated favorable 6-month outcomes postoperatively, whereas 63.5% of patients with ICP between 20 and 50 mm Hg and 33.3% with ICP greater than 50 mm Hg demonstrated favorable outcomes. Among 21 patients whose raised ICP did not respond to mannitol therapy, all experienced a poor outcome and 95.2% died. Among 145 patients whose elevated ICP responded to mannitol, 66.9% had a favorable outcome and only 20.7% were dead 6 months after surgery (p < 0.0001). According to results of multivariate analysis, however, ICP was not an independent outcome predictor (odds ratio 1.26, 95% confidence interval 0.28-5.68). CONCLUSIONS: Increased ICP is common after SAH, even in patients with a good clinical grade. Elevated ICP post-SAH is associated with a worse patient outcome, particularly if ICP does not respond to treatment. This association, however, may depend more on the overall severity of the SAH than on ICP alone.

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PubMed2004

The effect of nimodipine on cerebral oxygenation in patients with poor-grade subarachnoid hemorrhage.

OBJECT: Nimodipine has been shown to improve neurological outcome after subarachnoid hemorrhage (SAH); the mechanism of this improvement, however, is uncertain. In addition, adverse systemic effects such as hypotension have been described. The authors investigated the effect of nimodipine on brain tissue PO2. METHODS: Patients in whom Hunt and Hess Grade IV or V SAH had occurred who underwent aneurysm occlusion and had stable blood pressure were prospectively evaluated using continuous brain tissue PO2 monitoring. Nimodipine (60 mg) was delivered through a nasogastric or Dobhoff tube every 4 hours. Data were obtained from 11 patients and measurements of brain tissue PO2, intracranial pressure (ICP), mean arterial blood pressure (MABP), and cerebral perfusion pressure (CPP) were recorded every 15 minutes. Nimodipine resulted in a significant reduction in brain tissue PO2 in seven (64%) of 11 patients. The baseline PO2 before nimodipine administration was 38.4+/-10.9 mm Hg. The baseline MABP and CPP were 90+/-20 and 84+/-19 mm Hg, respectively. The greatest reduction in brain tissue PO2 occurred 15 minutes after administration, when the mean pressure was 26.9+/-7.7 mm Hg (p < 0.05). The PO2 remained suppressed at 30 minutes (27.5+/-7.7 mm Hg [p < 0.05]) and at 60 minutes (29.7+/-11.1 mm Hg [p < 0.05]) after nimodipine administration but returned to baseline levels 2 hours later. In the seven patients in whom brain tissue PO2 decreased, other physiological variables such as arterial saturation, end-tidal CO2, heart rate, MABP, ICP, and CPP did not demonstrate any association with the nimodipine-induced reduction in PO2. In four patients PO2 remained stable and none of these patients had a significant increase in brain tissue PO2. CONCLUSIONS: Although nimodipine use is associated with improved outcome following SAH, in some patients it can temporarily reduce brain tissue PO2.

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PubMed2002

Intramedullary injection of contrast into the cervical spinal cord during cervical myelography: a case report.

STUDY DESIGN: A case of iatrogenic intramedullary contrast injection during a C1-C2 cervical myelography is reported. OBJECTIVE: To investigate the occurrence of iatrogenic intramedullary contrast injection during a current C1-C2 cervical myelography. SUMMARY OF BACKGROUND DATA: Intramedullary injection of contrast is a rare but serious complication of C1-C2 cervical myelography that has not been reported since the widespread use of magnetic resonance imaging and the NASCIS III study protocol. METHODS: A 39-year-old woman received an iatrogenic intramedullary contrast injection during a C1-C2 cervical myelography. RESULTS: During the procedure the patient reported right-side face, neck, and arm pain and parethesias. After the procedure, right arm weakness and diffuse hyperreflexia developed. Postmyelography imaging demonstrated intramedullary contrast and cord swelling. High-dose methylprednisolone was administered intravenously and the patient's symptoms improved. The literature and management of this rare complication are reviewed. CONCLUSIONS: Intramedullary cord injection is a rare complication of cervical myelography. The mechanism of spinal cord injury appears to involve a combination of physical compression from the injected liquid and neurotoxicity of the contrast material. Iohexol rather than metrizamide should be used when C1-C2 myelography is indicated in patients who are unable to undergo magnetic resonance imaging, or those whose pathology is inadequately demonstrated magnetic resonance imaging alone. In the event of contrast injection into the spinal cord, administration of high-dose methylprednisolone is recommended.

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PubMed2002

Three-dimensional bone-free rendering of the cerebral circulation by use of computed tomographic angiography and fuzzy connectedness.

INTRODUCTION: Three-dimensional computed tomographic angiography (3-D-CTA) can be used to evaluate cerebrovascular disease. A potential limitation of this technology is obscuration of vascular anatomy by bone. In view of this, we developed a method for bone-free rendering using iterative relative fuzzy connectedness (IRFC) of 3-D-CTA to examine the cerebral vasculature without the intervening cranial base. METHODS: 3-D-CTA was obtained in 10 patients with cerebrovascular disease by use of an algorithm based on IRFC. Bone structures were removed and vascular anatomy was isolated with an almost completely automated process. Bone-removed images were rendered via maximum intensity projections, compared with digital subtraction angiography, and evaluated for vascular abnormalities. RESULTS: Compared with digital subtraction angiography, IRFC 3-D-CTA successfully defined the intracranial vascular anatomy in all 10 patients. An aneurysm was identified in 6 patients, bilateral carotid-cavernous fistulae in 1 patient, and no structural abnormalities in the remaining 3 patients. CONCLUSION: In 3-D-CTA, our preliminary findings suggest that bone obscuration, one of the current limitations of CTA, can be overcome through appropriate computer algorithms. We are now working on improving the computational efficiency of these algorithms to allow routine use of IRFC 3-D-CTA in an interventional or surgical suite.

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