Second brain death examination may negatively affect organ donation.

BACKGROUND: Little is known about the impact of the requirement for a second brain death examination on organ donation. In New York State, 2 examinations 6 hours apart have been recommended by a Department of Health panel. METHODS: We reviewed data for 1,229 adult and 82 pediatric patients pronounced brain dead in 100 New York hospitals serviced by the New York Organ Donor Network from June 1, 2007, to December 31, 2009. We reviewed the time interval between the 2 clinical brain death examinations and correlated this brain death declaration interval to day of the week, hospital size, and organ donation. RESULTS: None of the patients declared brain dead were found to regain brainstem function upon repeat examination. The mean brain death declaration interval between the 2 examinations was 19.2 hours. A 26% reduction in brain death examination frequency was seen on weekends when compared to weekdays (p = 0.0018). The mean brain death interval was 19.9 hours for 0-750 bed hospitals compared to 16.0 hours for hospitals with more than 750 beds (p = 0.0015). Consent for organ donation decreased from 57% to 45% as the brain death declaration interval increased. Conversely, refusal of organ donation increased from 23% to 36% as the brain death interval increased. A total of 166 patients (12%) sustained a cardiac arrest between the 2 examinations or after the second examination. CONCLUSION: A single brain death examination to determine brain death for patients older than 1 year should suffice. In practice, observation time to a second neurologic examination was 3 times longer than the proposed guideline and associated with substantial intensive care unit costs and loss of viable organs.

Emerging trends in ICU management and staffing.

It is likely that greater on-site intensivist coverage in critical care units will be observed in the future. Regionalization of critical care services will make this a financial reality because this level of expertise cannot realistically be provided to all hospitals. Perhaps units above a certain size will warrant this level of coverage and smaller community hospitals will transfer patients in need of a very high level of service, which can be provided only by intensivists on site. Community hospitals may rely on specially trained nurse practitioners or physician assistants to provide more on-site coverage during off hours. As technology advances, telemedicine will play a greater role in providing intensivist coverage to ICUs during off hours or to community hospitals in remote areas. Advanced technology and reorganization of critical care services offer opportunities for creative and nontraditional ways to deliver improved care to patients.

Other modalities of oxygen therapy: hyperbaric oxygen, nitric oxide, and ECMO.

Novel therapies for the next decade include hyperbaric oxygen, nitric oxide, and extracorporeal membrane oxygenation. Hyperbaric oxygen delivers oxygen at a pressure greater than one atmosphere and has been used in diseases ranging from decompression sickness to carbon monoxide poisoning. Inhaled nitric oxide, a potent vasodilator, has been used in the acute respiratory distress syndrome and for the diagnosis and treatment of pulmonary hypertension. Extracorporeal membrane oxygenation (ECMO) has been used to provide cardiopulmonary bypass support, particularly in the pediatric and neonatal population.

Magnetic resonance spectroscopy: use in monitoring MELAS treatment.

BACKGROUND: Sodium dichloroacetate has been used to treat patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). Magnetic resonance spectroscopy (MRS) has been used to assess cerebral metabolism in MELAS, but to our knowledge, the findings of serial MRS studies performed after therapeutic intervention of strokelike episodes have not been reported. METHODS: Proton MRS was serially used to measure brain metabolites in strokelike regions and in clinically uninvolved brain regions in a patient with MELAS. PATIENT: A patient with MELAS and a strokelike episode clinically improved after treatment with sodium dichloroacetate. An elevated lactate-creatine ratio in the "stroke" region decreased on MRS studies after treatment. After a second episode, the lactate-creatine ratio increased from baseline in a region of the brain that was normal on magnetic resonance imaging scans. CONCLUSIONS: To our knowledge, this is the first study to assess the response to treatment of a MELAS strokelike episode and the first to show an increase in the lactate-creatine ratio in a brain region that was associated with a clinical abnormality, even though it appeared normal on magnetic resonance imaging. We conclude that MRS may help to monitor therapeutic efficacy in mitochondrial encephalomyopathies.

Monocyte response to bacterial toxins, expression of cell surface receptors, and release of anti-inflammatory cytokines during sepsis.

Exposure to endotoxin produces a state of macrophage hyporesponsiveness on subsequent stimulation. Monocytes in patients with septic shock demonstrate a similar hyporesponsiveness to endotoxin. The purpose of this study was to examine whether this state of hyporesponsiveness extends to other inflammatory stimuli and the relationship of this state to cell surface receptor expression and the release of anti-inflammatory cytokines. Twelve normal volunteers, 10 patients with severe sepsis, and 9 patients with septic shock were included in the study. Monocytes from each subject were isolated and stimulated with lipopolysaccharide (LPS), staphylococcal enterotoxin B (SEB), and phorbol myristate acetate (PMA). Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were measured in the supernatants by enzyme-linked immunosorbent assay (ELISA). Serum levels of transforming growth factor-beta1 (TGF-beta1), prostaglandin E2 (PGE2), and interleukin-10 (IL-10) were also measured by ELISA. The expression of monocyte CD14 and HLA-DR in whole blood were measured by flow cytometry. Patients with septic shock demonstrated significantly decreased TNF-alpha and IL-1beta release as compared with normal subjects in response to LPS. In response to SEB, patients with sepsis and patient with septic shock demonstrated significantly decreased release of TNF-alpha and IL-1beta. Significant decreases in TNF-alpha release were found in the patients with septic shock after PMA stimulation. There were no significant differences in the monocyte response to the different stimuli between patients with gram-positive sepsis and gram-negative sepsis. HLA-DR expression was significantly decreased in patients with septic shock (58 +/- 9 fluorescence units (flU)) as compared with normal subjects (102 +/- 14 flU) (p < 0.05). No differences in CD14 expression were observed. IL-10 levels were significantly increased in patients with sepsis (16 +/- 4 pg/ml) and in patients with septic shock (42 +/- 15 pg/ml) and were detectable in 1 normal subject. TGF-beta1 levels were decreased in patients with septic shock (25 +/- 6 pg/ml) as compared with those in normal subjects (37 +/- 2 pg/ml)(p < 0.05). PGE2 levels were significantly increased in patients with septic shock and patients with sepsis. These data are consistent with a more generalized monocyte hyporesponsiveness to bacterial toxins that may be related to altered cell surface receptor expression and the release of anti-inflammatory cytokines.