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Biomedical subjects

Michael A Williams

Publications and source records attributed to Michael A Williams.

8 recordsLinked to original sources
PubMed2003

Critical care research on patients with advance directives or do-not-resuscitate status: ethical challenges for clinician-investigators.

Clinician-investigators face challenges in conducting research on critically ill patients when they have do-not-resuscitate orders, advance directives, or are in need of end-of-life care. Potential conflicts of interest for clinician-investigators include either financial stakes or academic and reputational stakes. The dual roles for intensive care unit physician or nurse clinician-investigators as healthcare professionals and scientists also present conflicts of interest, as does the dual purpose for the physical plant of the intensive care unit, which simultaneously serves as a site for patient care and a site for clinical research. Intensive care unit patients who become human research subjects also have dual roles that present conflict or confusion that can result in the therapeutic misconception. There are no scientifically or ethically sound reasons to exclude patients from participation in critical care research based on the presence of an advance directive or do-not-resuscitate order, as it would create a biased study sample that does not reflect the critically ill patient population, and it would treat a large group of potential research subjects differently from others without justification. There are four values in tension for critical care clinician-investigators in relation to patients/human research subjects: curative intent, palliative intent, research, and fiduciary obligations. A patient's decision to participate in research does not relieve clinician-investigators of their obligation to serve patient/human research subject's interests, even when doing so involves decisions to limit or withdraw life-sustaining interventions or withdraw the patient/human research subject from research. Critical care research involving patients with advance directives or do-not-resuscitate status is both possible and desirable because it is just, respects patient autonomy, and results in study populations that better reflect the clinical population in all respects.

Advance Directives↗
PubMed2003

The physician's role in discussing organ donation with families.

Federal Conditions of Participation from the Health Care Financing Administration (now the Centers for Medicare and Medicaid Services) introduced in 1998 require that all families be presented the option of organ and tissue donation when death is imminent. The perception that physicians were being excluded from participating in this process led to a resolution at the American Medical Association House of Delegates meeting in December 1999, calling on the American Medical Association Council on Scientific Affairs to review the Conditions of Participation "to ensure that there is no prohibition of physician involvement in the organ donation process..." The number of organs procured for transplantation in the United States is insufficient to meet needs. Families' hospital experiences significantly affect their decisions to donate organs. Discussing severe brain injury, brain death, and organ donation after brain death with families is a specialized form of end-of-life decision-making and care in the intensive care unit; however, the knowledge, skills, and attitudes necessary for physicians and nurses to promote good end-of-life decision-making are widely variable. The federal Conditions of Participation require that those making requests of families for organ donation receive specific training. They do not prohibit physician involvement in initiating organ donation requests, provided these individuals are properly trained. Physicians have an important role in caring for patients and families in these circumstances, and the care they provide is enhanced through training, attention to the special issues involved, and collaboration with organ procurement organization personnel.

Attitude to Death↗
PubMed2002

The integration of palliative care and critical care: one vision, one voice.

As technological advances transform health care and the American population ages, care at the end of life (EOL) assumes ever-greater significance. Nurses in all practice settings and specialties are challenged to integrate quality palliative care into patient care. Today, this imperative is unifying the nursing profession, with help of the Nursing Leadership Academy for End-of-Life Care.

Critical Care↗
PubMed2002

Symptomatic vasospasm diagnosis after subarachnoid hemorrhage: evaluation of transcranial Doppler ultrasound and cerebral angiography as related to compromised vascular distribution.

OBJECTIVE: To evaluate the reliability of transcranial Doppler ultrasound in detecting symptomatic vasospasm in patients after aneurysmal subarachnoid hemorrhage and monitoring response after hypertensive and endovascular treatments. DESIGN: Retrospective chart review. SETTING: Neurosciences critical care unit in a tertiary-care university hospital. PATIENTS: All patients admitted to a neurosciences critical care unit with the diagnosis of subarachnoid hemorrhage between January 1990 and June 1997. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: We reviewed transcranial Doppler ultrasound data of 199 patients; 55 had symptomatic vasospasm. Clinical symptoms and corresponding vascular distributions were identified, as was angiographic vasospasm (n = 35). The sensitivity and specificity of transcranial Doppler ultrasound for anterior circulation vessels were calculated by using a mean cerebral blood flow velocity criterion of >120 cm/sec. Clinical diagnosis of symptomatic vasospasm was used as the standard to determine sensitivity and specificity of transcranial Doppler ultrasound and cerebral angiography. The sensitivity of transcranial Doppler ultrasound for anterior circulation in patients with symptomatic vasospasm was 73% with a specificity of 80%. The sensitivity of cerebral angiography was 80%. For individual vessels, the sensitivity and specificity of transcranial Doppler ultrasound were middle cerebral artery, 64% and 78%; anterior cerebral artery, 45% and 84%; and internal carotid artery, 80% and 77%, respectively. The mean times for symptomatic and transcranial Doppler ultrasound signs of vasospasm presentation were 6.4 +/- 2 and 6.1 +/- 3 days, respectively. In patients without symptomatic vasospasm, the mean time for mean cerebral blood flow velocities >120 cm/sec was 7.0 +/- 3 days (p <.05). Symptomatic vasospasm also was associated with thickness of clot on head computed tomography scan and rapidly increasing mean cerebral blood flow velocities. Transcranial Doppler ultrasound signs of vasospasm improved after endovascular treatment in 30 patients. CONCLUSIONS: The reliability of transcranial Doppler ultrasound was better at detecting high mean cerebral blood flow velocities in patients with symptomatic vasospasm related to middle cerebral and internal carotid artery distributions than for anterior cerebral artery distribution. Transcranial Doppler ultrasound was as sensitive as cerebral angiography at detecting symptomatic vasospasm. High mean cerebral blood flow velocities can be apparent before the presence of symptomatic vasospasm. Daily transcranial Doppler ultrasound monitoring could provide early identification of patients with aneurysmal subarachnoid hemorrhage who are at high risk for symptomatic vasospasm and may be helpful at following success of endovascular treatment.

Cerebral Angiography↗
PubMed2002

Ventilatory care in myasthenia gravis crisis: assessing the baseline adverse event rate.

OBJECTIVE: Myasthenic patients who require mechanical ventilation often develop pneumonia or atelectasis. Although there are differences in the prevalence of these complications among various institutions, there is no evidence that aggressive treatment shortens the course of the myasthenic crisis. We have quantified the severity of lung injury and aggressiveness of respiratory intervention in myasthenic patients admitted to the neuro-critical care unit. DESIGN: We retrospectively identified all mechanically ventilated myasthenic patients admitted in our unit between 1990 and 1998. SETTING: Neuro-critical care unit of a tertiary care center in an urban area with a large, established, regional neuromuscular disease program. PATIENTS: Eighteen myasthenia gravis patients with 24 episodes of respiratory failure requiring mechanical ventilation. INTERVENTIONS: A novel respiratory intervention index, comprising the use of suction, intermittent positive-pressure breathing or bronchodilator treatments, sighs, and chest physiotherapy represented the aggressiveness of the respiratory treatment. The respiratory intervention index was correlated with the lung injury score, used as a measure of lung involvement and other respiratory variables. MEASUREMENTS AND MAIN RESULTS Our patients had less atelectasis and pneumonia than previously published series (46% vs. 91%), leading to shorter mechanical support and neuro-critical care unit stay. The mean respiratory intervention index correlated with lung injury score and inversely with forced vital capacity. CONCLUSIONS: This study presents an estimate for both severity of pulmonary complications and intensity of respiratory therapy in the severe myasthenic patient with mechanical ventilatory compromise. Our results suggest that aggressive respiratory treatment should be used in myasthenic patients in crisis to diminish the risk for prolonged respiratory complications. These observations should be validated in a prospective study.

Aged↗
PubMed2002

Interhemispheric intracranial pressure gradients in massive cerebral infarction.

We report continuous bilateral intracranial pressure (ICP) monitoring immediately after transtentorial herniation in a patient with massive cerebral infarction to: 1) determine presence and time course of compartmental ICP differences, and 2) to study effects of therapy on both hemispheres. A 55-year-old man admitted with watershed infarctions in the left anterior-middle-posterior cerebral arteries distribution. Initial investigations demonstrated highly narrowed left extracranial internal carotid artery. Eight days later he developed unexplained lethargy and anisocoria. Head computerized tomography (CT) showed massive left hemispheric infarction, edema, and midline shift. Bilateral subarachnoid bolts demonstrated equally elevated ICP in both hemispheres. Hyperventilation and osmotic therapy produced near-identical ICP reduction bilaterally with resolution of anisocoria. Later, plateau waves and autonomic instability developed. Shortly before loss of brainstem function, interhemispheric ICP gradients (left greater than right) of 30-40 mm Hg developed. Intracranial pressure did not equalize prior to brain death determination. Bilateral ICP monitoring did not reveal an interhemispheric ICP gradient soon after transtentorial herniation in massive MCA infarction. The presence of interhemispheric ICP gradients in massive stroke remains unproven and further clinical study is necessary.

Dysarthria↗