Biomedical subjects

David W Newell

Publications and source records attributed to David W Newell.

At least 19 recordsLinked to original sources

PubMed2007

Magnesium sulfate for neuroprotection after traumatic brain injury: a randomised controlled trial.

BACKGROUND: Traumatic brain injuries represent an important and costly health problem. Supplemental magnesium positively affects many of the processes involved in secondary injury after traumatic brain injury and consistently improves outcome in animal models. We aimed to test whether treatment with magnesium favourably affects outcome in head-injured patients. METHODS: In a double-blind trial, 499 patients aged 14 years or older admitted to a level 1 regional trauma centre between August, 1998, and October, 2004, with moderate or severe traumatic brain injury were randomly assigned one of two doses of magnesium or placebo within 8 h of injury and continuing for 5 days. Magnesium doses were targeted to achieve serum magnesium ranges of 1.0-1.85 mmol/L or 1.25-2.5 mmol/L. The primary outcome was a composite of mortality, seizures, functional measures, and neuropsychological tests assessed up to 6 months after injury. Analyses were done according to the intention-to-treat principle. This trial is registered with , number . FINDINGS: Magnesium showed no significant positive effect on the composite primary outcome measure at the higher dose (mean=55 average percentile ranking on magnesium vs 52 on placebo, 95% CI for difference -7 to 14; p=0.70). Those randomly assigned magnesium at the lower dose did significantly worse than those assigned placebo (48 vs 54, 95% CI -10.5 to -2; p=0.007). Furthermore, there was higher mortality with the higher magnesium dose than with placebo. Other major medical complications were similar between groups, except for a slight excess of pulmonary oedema and respiratory failure in the lower magnesium target group. No subgroups were identified in which magnesium had a significantly positive effect. INTERPRETATION: Continuous infusions of magnesium for 5 days given to patients within 8 h of moderate or severe traumatic brain injury were not neuroprotective and might even have a negative effect in the treatment of significant head injury.

Adolescent↗

PubMed2006

Impact of basilar artery vasospasm on outcome in patients with severe cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The purpose of the present study was to evaluate the impact of basilar artery (BA) vasospasm on outcome in patients with severe vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). METHODS: Sixty-five patients with clinically suspect severe cerebral vasospasm after aSAH underwent cerebral angiography before endovascular treatment. Vasospasm severity was assessed for each patient by transcranial Doppler measurements, angiography, and (99m)Tc-ethylcysteinate dimer single-photon emission computed tomography (ECD-SPECT) imaging. Percentage of BA narrowing was calculated in reference to the baseline angiogram. RESULTS: BA narrowing >or=25% was found in 23 of 65 patients, and delayed brain stem (BS) hypoperfusion, as estimated by ECD-SPECT, was found in 16. Fourteen of 23 patients with BA narrowing >or=25% experienced BS hypoperfusion, whereas only 2 of 42 patients with >or=25% BA narrowing experienced BS ischemia (P<0.001). Stepwise logistic regression after adjusting for age with Hunt and Hess grade, Fisher grade, hydrocephalus, and aneurysmal location as covariables revealed BA narrowing >or=25% and delayed BS hypoperfusion to be significantly and independently associated with unfavorable 3-month outcome (P=0.0001; odds ratio, 10.1; 95% CI, 2.5 to 40.8; and P=0.007; odds ratio, 13.8, 95% CI, 2.18 to 91.9, respectively). CONCLUSIONS: These findings suggest for the first time that BA vasospasm after aSAH is an independent and significant prognostic factor associated with poor outcome in patients with severe cerebral vasospasm requiring endovascular therapy. Further study should be done to evaluate the role of interventional therapy on outcome in patients with posterior circulation vasospasm.

Adult↗

PubMed2006

Cerebral aneurysms.

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Aneurysm, Ruptured↗

PubMed2006

Intraoperative jugular bulb desaturation during acute aneurysmal rupture.

PURPOSE: To describe an episode of acute jugular venous desaturation during intraoperative rupture of a cerebral aneurysm. CLINICAL FEATURES: A 57-yr-old patient was scheduled for clipping of a large unruptured basilar tip aneurysm. Abrupt bulging of the brain was observed after bone flap removal, but before dura was opened. This was associated with concurrent development of systemic hypertension to 200/120 mmHg and jugular venous bulb (S(jv)O(2)) desaturation to 13%. Rupture of aneurysm was confirmed by frank blood in cerebrospinal fluid drainage from the lumbar subarachnoid catheter. CONCLUSIONS: Abrupt S(jv)O(2) desaturation prior to dural opening may suggest an acute increase in intracranial pressure, which in our case followed aneurysmal rupture; the systemic response to increased intracranial pressure (Cushing's response) may be ineffective in maintaining cerebral perfusion.

Acute Disease↗

PubMed2006

Acute lung injury in patients with subarachnoid hemorrhage: incidence, risk factors, and outcome.

OBJECTIVE: Pulmonary complications account for significant morbidity and mortality following aneurysmal subarachnoid hemorrhage; however, the effect of acute lung injury is largely unknown. The goal of this study was to determine the incidence of acute lung injury in a large cohort of patients with subarachnoid hemorrhage as well as determine the risk factors for acute lung injury and its effect on mortality and length of stay. Ventilator management was analyzed to determine the proportion of patients with subarachnoid hemorrhage and acute lung injury who a received a low-tidal volume ventilation strategy. DESIGN: Retrospective cohort study. SETTING: University-affiliated county hospital in Seattle, WA. PATIENTS: Six-hundred and twenty patients with aneurysmal subarachnoid hemorrhage documented on computed tomography or angiography. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One-hundred and seventy patients met criteria for acute lung injury (incidence, 27%; 95% confidence interval, 24-31%). On multivariate analysis, severity of illness, clinical grade of hemorrhage, packed red blood cell transfusions, and severe sepsis in the intensive care unit were independently associated with development of acute lung injury. After adjustment for important confounders, development of acute lung injury was associated with a statistically significant increase in hospital mortality (odds ratio, 1.63; 95% confidence interval, 1.03-2.57). Acute lung injury was also independently associated with an increased intensive care unit length of stay (15%, 95% confidence interval, 5-27%). Thirty percent of patients with acute lung injury received low tidal volume ventilation. Patients receiving low tidal volume ventilation had worse oxygenation and higher positive end-expiratory pressure requirements compared with those who did not, but there were no significant differences in arterial pH or Pco2. CONCLUSIONS: Acute lung injury is common in patients with subarachnoid hemorrhage and is independently associated with a worse clinical outcome. Research is needed to determine the causes of acute lung injury in this population and whether these patients are candidates for evidence-based ventilator strategies to reduce mortality.

Adult↗

PubMed2006

Neurointerventional treatment of vasospasm.

OBJECTIVES: To review the historical development and current status of endovascular techniques used in the treatment of symptomatic vasospasm following aneurysmal subarachnoid hemorrhage. METHODS: This article summarizes the relevant literature on neurointerventional therapy for vasospasm, namely instillation of intraarterial medication (papaverine, nicardipine, verapamil) and transluminal balloon angioplasty. The authors synthesize the available literature with their own experience using the various endovascular modalities to treat vasospasm at high volume cerebrovascular centers. TECHNIQUE: Indications for the use of neurointerventional therapy as well as a summary of the technique for transluminal angioplasty to treat vasospasm as employed by the authors is described. DISCUSSION: Neurointerventional treatment of vasospasm following aneurysmal hemorrhage has been proven to be a safe and successful technique for those patients suffering symptomatic vasospasm refractory to medical management. The techniques contunue to undergo refinement as endovascular technology advances. We currently favor the use of balloon angioplasty over intraarterial antispasmotics due to the increased durability and long-lasting effects of the former and lower risk profile.

Angioplasty, Balloon↗

PubMed2006

Cystic dilation of the conus ventriculus terminalis presenting as an acute cauda equina syndrome relieved by decompression and cyst drainage: case report.

OBJECTIVE AND IMPORTANCE: The ventriculus terminalis of the conus, or "fifth ventricle" refers to the ependymal-lined space in the middle of the conus that is present in childhood and whose persistence into adulthood is rare. A number of cases of cystic dilatation of the ventriculus terminalis have been described in adulthood. Patients tend to present with either pain alone or gradually progressive conus or cauda equina syndromes with varying degrees of recovery after cyst drainage. Presentation with an acute cauda equina syndrome and its successful surgical management has not been previously reported. CLINICAL PRESENTATION: A 57-year-old woman experienced back pain and bilateral sciatica ascribed to diabetic neuropathy for 2 years. Over a 24-hour period she developed bilateral lower extremity weakness, saddle anesthesia, and bowel and bladder incontinence. Lumbosacral magnetic resonance imaging demonstrated a large cystic dilatation of the ventriculus terminalis. INTERVENTION: She was taken for emergency surgical decompression and cyst drainage. Immediately after surgery, she experienced significant increase in lower extremity strength and has since regained continence. CONCLUSION: Cystic dilation of the ventriculus terminalis should be part of the differential diagnosis for a cauda equina syndrome; surgical decompression with simple cyst drainage can result in excellent clinical results.

Decompression, Surgical↗

PubMed2006

Surgical management of traumatic parenchymal lesions.

INDICATIONS: Patients with parenchymal mass lesions and signs of progressive neurological deterioration referable to the lesion, medically refractory intracranial hypertension, or signs of mass effect on computed tomographic (CT) scan should be treated operatively. Patients with Glasgow Coma Scale (GCS) scores of 6 to 8 with frontal or temporal contusions greater than 20 cm3 in volume with midline shift of at least 5 mm and/or cisternal compression on CT scan, and patients with any lesion greater than 50 cm3 in volume should be treated operatively. Patients with parenchymal mass lesions who do not show evidence for neurological compromise, have controlled intracranial pressure (ICP), and no significant signs of mass effect on CT scan may be managed nonoperatively with intensive monitoring and serial imaging. TIMING AND METHODS: Craniotomy with evacuation of mass lesion is recommended for those patients with focal lesions and the surgical indications listed above, under Indications. Bifrontal decompressive craniectomy within 48 hours of injury is a treatment option for patients with diffuse, medically refractory posttraumatic cerebral edema and resultant intracranial hypertension. Decompressive procedures, including subtemporal decompression, temporal lobectomy, and hemispheric decompressive craniectomy, are treatment options for patients with refractory intracranial hypertension and diffuse parenchymal injury with clinical and radiographic evidence for impending transtentorial herniation.

Craniocerebral Trauma↗

PubMed2006

Surgical management of posterior fossa mass lesions.

INDICATIONS: Patients with mass effect on computed tomographic (CT) scan or with neurological dysfunction or deterioration referable to the lesion should undergo operative intervention. Mass effect on CT scan is defined as distortion, dislocation, or obliteration of the fourth ventricle; compression or loss of visualization of the basal cisterns, or the presence of obstructive hydrocephalus. Patients with lesions and no significant mass effect on CT scan and without signs of neurological dysfunction may be managed by close observation and serial imaging. TIMING: In patients with indications for surgical intervention, evacuation should be performed as soon as possible because these patients can deteriorate rapidly, thus, worsening their prognosis. METHODS: Suboccipital craniectomy is the predominant method reported for evacuation of posterior fossa mass lesions, and is therefore recommended.

Brain↗

PubMed2006

Surgical management of depressed cranial fractures.

INDICATIONS: Patients with open (compound) cranial fractures depressed greater than the thickness of the cranium should undergo operative intervention to prevent infection. Patients with open (compound) depressed cranial fractures may be treated nonoperatively if there is no clinical or radiographic evidence of dural penetration, significant intracranial hematoma, depression greater than 1 cm, frontal sinus involvement, gross cosmetic deformity, wound infection, pneumocephalus, or gross wound contamination. Nonoperative management of closed (simple) depressed cranial fractures is a treatment option. TIMING: Early operation is recommended to reduce the incidence of infection. METHODS: Elevation and debridement is recommended as the surgical method of choice. Primary bone fragment replacement is a surgical option in the absence of wound infection at the time of surgery. All management strategies for open (compound) depressed fractures should include antibiotics.

Disease Management↗

PubMed2006

Dynamic perfusion computed tomography in the diagnosis of cerebral vasospasm.

OBJECTIVE: The aim of the study was to correlate absolute cerebral blood flow (CBF) and mean transient time (MTT) measured by dynamic perfusion computed tomographic (PCT) scanning with the clinical course, vasospasm severity, and perfusion abnormality in patients with cerebral vasospasm after aneurysmal subarachnoid hemorrhage. METHODS: Forty-six patients with vasospasm after aneurysmal subarachnoid hemorrhage had 63 PCT images obtained during the course of vasospasm. All patients had transcranial Doppler measurements, 28 had an angiography study, and 38 had 99mTc single-photon emission computed tomographic imaging performed in conjunction with the PCT scan. RESULTS: The average minimal regional CBF (rCBF) and maximal regional MTT in patients with delayed ischemic deficit were significantly different in comparison with patients without delayed ischemic deficit (22.6 +/- 11.2 cm3/100 g/min versus 45.2 +/- 21.3 cm3/100 g/min, P < 0.001; 7.3 +/- 2.5 s versus 3.3 +/- 1.7 s, P < 0.05). The average minimal rCBF and maximal regional MTT in middle cerebral vascular territories in which severe middle cerebral artery vasospasm was measured by transcranial Doppler were significantly different in comparison with middle cerebral vascular territories in which no vasospasm was measured by transcranial Doppler (29.3 +/- 1.7 cm3/100 g/min versus 54.1 +/- 25.4 cm3/100 g/min, P < 0.01; 4.5 +/- 2.4 s versus 2.8 +/- 1.1 P < 0.001). The average minimal rCBF and maximal rMTT in vascular territories with estimated severe hypoperfusion on single-photon emission computed tomographic imaging were significantly different in comparison with values in vascular territories with unimpaired perfusion as estimated by single-photon emission computed tomographic imaging (18.9 +/- 6.9 cm3/100 g/min versus 54.2 +/- 23.4 cm3/100 g/min, P < 0.001, 0.001; 8.1 +/- 1.9 s versus 2.5 +/- 0.39 s, P < 0.001). CONCLUSION: The present study suggests that, in general, quantitative measurements of rCBF and regional MTT by PCT show high concordance rates with the clinical course, vasospasm severity, and hemodynamic impairments in patients with cerebral vasospasm aneurysmal subarachnoid hemorrhage.

Adult↗

PubMed2006

Transcranial Doppler grading criteria for basilar artery vasospasm.

OBJECTIVE: Transcranial Doppler (TCD) criteria for basilar artery (BA) vasospasm are poorly defined, and grading criteria for vertebrobasilar vasospasm are unavailable. The purpose of the present study was to define TCD grading criteria for BA vasospasm on the basis of the absolute flow velocities and the intracranial to extracranial flow velocity ratios for the posterior circulation, and to improve the sensitivity and specificity of TCD for diagnosis of BA vasospasm. METHODS: One hundred twenty-three patients with aneurysmal subarachnoid hemorrhage underwent 144 cerebral arteriograms with views of the BA during the acute phase of vasospasm (Days 3-14 after hemorrhage). BA diameters were measured and compared with diameters obtained from baseline arteriograms. Both BA and extracranial vertebral artery flow velocities were measured by TCD within 4 hours before the arteriogram. RESULTS: The velocity ratio between the BA and the extracranial vertebral arteries (VA) strongly correlated with the degree of BA narrowing (r2 = 0.648; P < 0.0001). A ratio higher than 2.0 was associated with 73% sensitivity and 80% specificity for BA vasospasm. A ratio higher than 2.5 with BA velocity greater than 85 cm/s was associated with 86% sensitivity and 97% specificity for BA narrowing of more than 25%. A BA/VA ratio higher than 3.0 with BA velocities higher than 85 cm/s was associated with 92% sensitivity and 97% specificity for BA narrowing of more than 50%. CONCLUSION: The BA/VA ratio improves the sensitivity and specificity of TCD detection of BA vasospasm. On the basis of the BA/VA ratio and BA mean velocities, we suggest new TCD grading criteria for BA vasospasm.

Adult↗

PubMed2006

Dynamic perfusion computerized tomography in cerebral vasospasm following aneurysmal subarachnoid hemorrhage: a comparison with technetium-99m-labeled ethyl cysteinate dimer-single-photon emission computerized tomography.

OBJECT: The aim of this study was to correlate cerebral blood flow (CBF) and mean transient time (MTT) measured on dynamic perfusion computerized tomography (CT) with CBF using (99m)Tc ethyl cysteinate dimer-single-photon emission computerized tomography (SPECT) in patients with cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). METHODS: Thirty-five patients with vasospasm following aneurysmal SAH (12 men and 23 women with a mean age of 49.3 +/- 10.1 years) underwent imaging studies; thus, 35 perfusion CT scans and 35 SPECT images were available for comparison. The CBF and MTT values in 12 different brain regions were defined relative to the interhemispheric occipital cortex values using perfusion CT scans and were compared with qualitative relative (rel)CBF estimated on SPECT images. In brain regions with normal, mild (relCBF 71-85%), moderate (relCBF 50-70%), and severe (relCBF < 50%) hypoperfusion on SPECT, the mean relCBF values measured on perfusion CT were 1.01 +/- 0.08, 0.82 +/- 0.22, 0.6 +/- 0.15, and 0.32 +/- 0.08, respectively (p < 0.0001); the mean relMTT values were 1.04 +/- 0.14, 1.4 +/- 0.31, 2.16 +/- 0.46, and 3.3 +/- 0.54, respectively (p < 0.0001). All but one brain region (30 regions) with severe hypoperfusion on SPECT images demonstrated relCBF values less than 0.6 and relMTT values greater than 2.5 on perfusion CT scans. CONCLUSIONS: Relative CBF and MTT values on perfusion CT showed a high concordance rate with estimated relCBF on SPECT in patients with vasospasm following aneurysmal SAH. Given its logistical advantages, perfusion CT may be a valuable method of assessing perfusion abnormality in the acute setting of vasospasm and in patients with an unstable condition following aneurysmal SAH.

Adult↗

PubMed2006

Diagnosis and treatment of craniocervical dislocation in a series of 17 consecutive survivors during an 8-year period.

OBJECT: Craniocervical dissociation (CCD) is a highly unstable and usually fatal injury resulting from osseoligamentous disruption between the occiput and C-2. The purpose of this study was to elucidate systematic factors associated with delays in diagnosing and treating this life-threatening condition and to introduce an injury-severity classification with therapeutic implications. METHODS: In a retrospective evaluation of institutional databases, the authors reviewed medical records and original images obtained in 17 consecutive surviving patients with CCD treated between 1994 and 2002. Images and clinical results of treatment were evaluated, emphasizing the timing of diagnosis, clinical effect of delayed diagnosis, potential clinical or imaging warning signs, and response to treatment. Craniocervical dissociation was identified or suspected on the initial lateral cervical spine radiograph acquired in two patients (12%) and was diagnosed based on screening computerized tomography findings in two additional patients (12%). A retrospective review of initial lateral x-ray films showed an abnormal dens-basion interval in 16 patients (94%). The 2-day average delay in diagnosis was associated with profound neurological deterioration in five patients (29%). Neurological status declined in one patient after a fixation procedure was performed. There were no cases of craniocervical pseudarthrosis or hardware failure during a mean 26-month follow-up period. The mean American Spinal Injury Association (ASIA) motor score of 50 improved to 79, and the number of patients with useful motor function (ASIA Grade D or E) increased from seven (41%) preoperatively to 13 (76%) postoperatively. CONCLUSIONS: The diagnosis of CCD was frequently delayed, and the delay was associated with an increased likelihood of neurological deterioration. Early diagnosis and spinal stabilization protected against worsening spinal cord injury.

Adolescent↗

PubMed2006

Cerebrovascular dynamics with head-of-bed elevation in patients with mild or moderate vasospasm after aneurysmal subarachnoid hemorrhage.

BACKGROUND: In patients with aneurysmal subarachnoid hemorrhage, elevation of the head of the bed during vasospasm has been limited in an attempt to minimize vasospasm or its sequelae or both. Consequently, some patients have remained on bed rest for weeks. OBJECTIVES: To determine how elevations of the head of the bed of 20 degrees and 45 degrees affect cerebrovascular dynamics in adult patients with mild or moderate vasospasm after aneurysmal subarachnoid hemorrhage and to describe the response of mild or moderate vasospasm to head-of-bed elevations of 20 degrees and 45 degrees with respect to variables such as grade of subarachnoid hemorrhage and degree of vasospasm. METHODS: A within-patient repeated-measures design was used. The head of the bed was positioned in the sequence of 0 degrees -20 degrees -45 degrees -0 degrees in 20 patients with mild or moderate vasospasm between days 3 and 14 after aneurysmal subarachnoid hemorrhage. Continuous transcranial Doppler recordings were obtained for 2 to 5 minutes after allowing approximately 2 minutes for stabilization in each position. RESULTS: No patterns or trends indicated that having the head of the bed elevated increases vasospasm. As a group, there were no significant differences within patients at the different positions of the head of the bed. Utilizing repeated-measures analysis of variance, P values ranged from .34 to .97, well beyond .05. No neurological deterioration occurred. CONCLUSIONS: In general, elevation of the head of the bed did not cause harmful changes in cerebral blood flow related to vasospasm.

Adolescent↗

PubMed2006

Surgical management of acute epidural hematomas.

INDICATIONS FOR SURGERY: An epidural hematoma (EDH) greater than 30 cm3 should be surgically evacuated regardless of the patient's Glasgow Coma Scale (GCS) score. An EDH less than 30 cm3 and with less than a 15-mm thickness and with less than a 5-mm midline shift (MLS) in patients with a GCS score greater than 8 without focal deficit can be managed nonoperatively with serial computed tomographic (CT) scanning and close neurological observation in a neurosurgical center. TIMING: It is strongly recommended that patients with an acute EDH in coma (GCS score < 9) with anisocoria undergo surgical evacuation as soon as possible. METHODS: There are insufficient data to support one surgical treatment method. However, craniotomy provides a more complete evacuation of the hematoma.

Disease Management↗

PubMed2006

Surgical management of acute subdural hematomas.

INDICATIONS FOR SURGERY: An acute subdural hematoma (SDH) with a thickness greater than 10 mm or a midline shift greater than 5 mm on computed tomographic (CT) scan should be surgically evacuated, regardless of the patient's Glasgow Coma Scale (GCS) score. All patients with acute SDH in coma (GCS score less than 9) should undergo intracranial pressure (ICP) monitoring. A comatose patient (GCS score less than 9) with an SDH less than 10-mm thick and a midline shift less than 5 mm should undergo surgical evacuation of the lesion if the GCS score decreased between the time of injury and hospital admission by 2 or more points on the GCS and/or the patient presents with asymmetric or fixed and dilated pupils and/or the ICP exceeds 20 mm Hg. TIMING: In patients with acute SDH and indications for surgery, surgical evacuation should be performed as soon as possible. METHODS: If surgical evacuation of an acute SDH in a comatose patient (GCS < 9) is indicated, it should be performed using a craniotomy with or without bone flap removal and duraplasty.

Disease Management↗

PubMed2006

Effect of continuous display of cerebral perfusion pressure on outcomes in patients with traumatic brain injury.

BACKGROUND: Clinical bedside monitoring systems do not provide prominent displays of data on cerebral perfusion pressure (CPP). Immediate visual feedback would allow more rapid intervention to prevent or minimize suboptimal pressures. OBJECTIVE: To evaluate the effect of a highly visible CPP display on immediate and long-term functional outcome in patients with traumatic brain injury. METHODS: A total of 157 patients with traumatic brain injury at a level 1 trauma center who had invasive arterial blood pressure and intracranial pressure monitoring were randomized to beds with or without an additional, prominent continuous CPP display. Primary end points were scores on the Extended Glasgow Outcome Scale (GOSE) and Functional Status Examination (FSE) 6 months after injury. Secondary end points were GOSE scores at discharge and 3 months after injury and FSE score 3 months after injury. RESULTS: Although GOSE and FSE scores at 6 months were better in the group with the highly visible CPP display, the differences were not significant. Slope of recovery for GOSE and FSE over all follow-up time points did not differ significantly between groups. However, the intervention's positive effect on odds of survival at hospital discharge was strong and significant. Within a subgroup of more severely injured patients, the intervention group was much less likely than the control group to have CPP deviations. CONCLUSIONS: The presence of a highly visible display of CPP was associated with significantly better odds of survival and overall condition at discharge.

Adult↗