CORRESPONDENCE birth to adulthood in rhesus monkeys. Am J Physiol Lung Cell Mol Physiol 2007;293:L570–L579. 3. Kovar J, Sly PD, Willet KE. Postnatal alveolar development of the rabbit. J Appl Physiol (1985) 2002;93:629–635. 4. Schittny JC, Mund SI, Stampanoni M. Evidence and structural mechanism for late lung alveolarization. Am J Physiol Lung Cell Mol Physiol 2008;294:L246–L254. 5. Massaro D, Massaro GD, Baras A, Hoffman EP, Clerch LB. Calorierelated rapid onset of alveolar loss, regeneration, and changes in mouse lung gene expression. Am J Physiol Lung Cell Mol Physiol 2004;286:L896–L906. 6. Hsia CC, Herazo LF, Fryder-Doffey F, Weibel ER. Compensatory lung growth occurs in adult dogs after right pneumonectomy. J Clin Invest 1994;94:405–412. 7. Butler JP, Loring SH, Patz S, Tsuda A, Yablonskiy DA, Mentzer SJ. Evidence for adult lung growth in humans. N Engl J Med 2012;367:244–247. 8. Mitra PP, Sen PN, Schwartz LM. Short-time behavior of the diffusion coefficient as a geometrical probe of porous media. Phys Rev B Condens Matter 1993;47:8565–8574. 9. Haefeli-Bleuer B, Weibel ER. Morphometry of the human pulmonary acinus. Anat Rec 1988;220:401–414. 10. Hansen JE, Ampaya EP. Human air space shapes, sizes, areas, and volumes. J Appl Physiol 1975;38:990–995. 11. Schreider JP, Raabe OG. Structure of the human respiratory acinus. Am J Anat 1981;162:221–232. 12. Parra-Robles J, Wild JM. The influence of lung airways branching structure and diffusion time on measurements and models of shortrange 3He gas MR diffusion. J Magn Reson 2012;225:102–113. 13. J. Parra-Robles JMW. On the validity of 3He diffusion MRI evidence of neo-alveolarization in lungs: the effects of branching structure [abstract]. Proc Intl Soc Magn Reson Med Sci Meet Exhib 2013;21:1469. 14. Hansen JE, Ampaya EP. Lung morphometry: a fallacy in the use of the counting principle. J Appl Physiol 1974;37:951–954. 15. Thurlbeck WM. Postnatal human lung growth. Thorax 1982;37:564–571. 16. Smaldone GC, Mitzner W. Viewpoint: unresolved mysteries. J Appl Physiol (1985) 2012;113:1945–1947. 17. Peces-Barba G, Ruiz-Cabello J, Cremillieux Y, Rodr´ıguez I, Dupuich D, Callot V, Ortega M, Rubio Arbo ML, Cortijo M, Gonzalez-Mangado N. Helium-3 MRI diffusion coefficient: correlation to morphometry in a model of mild emphysema. Eur Respir J 2003;22:14–19. 18. Chen XJ, Hedlund LW, Moller ¨ HE, Chawla MS, Maronpot RR, Johnson GA. Detection of emphysema in rat lungs by using magnetic resonance measurements of 3He diffusion. Proc Natl Acad Sci USA 2000;97:11478–11481. 19. Woods JC, Choong CK, Yablonskiy DA, Bentley J, Wong J, Pierce JA, Cooper JD, Macklem PT, Conradi MS, Hogg JC. Hyperpolarized 3He diffusion MRI and histology in pulmonary emphysema. Magn Reson Med 2006;56:1293–1300. 20. Yablonskiy DA, Sukstanskii AL, Woods JC, Gierada DS, Quirk JD, Hogg JC, Cooper JD, Conradi MS. Quantification of lung microstructure with hyperpolarized 3He diffusion MRI. J Appl Physiol (1985) 2009; 107:1258–1265.

Copyright © 2014 by the American Thoracic Society

Donation after Circulatory Determination of Death: We Need to Respect and Protect Brain-injured Patients To the Editor: Organ donation and transplantation are life-saving practices. Providing the option of donation is an important component of end-of-life care. Gries and colleagues have contributed a helpful statement, approved by several organizations, regarding ethical issues in controlled donation after circulatory determination of death (DCD) (1). We would like to emphasize additional important considerations 504

that are required to protect brain-injured patients, who are most often the individuals who become deceased organ donors. First, it is crucial that surrogate decision makers are given balanced and accurate prognostic information before a decision to withdraw life-sustaining interventions is reached. If the best possible outcome with life-sustaining interventions is to remain permanently and severely disabled, then many patients prefer, as expressed by their surrogates, to have these interventions withdrawn, even if the implication is death. Surrogates depend heavily on information provided by intensivists in making these difficult decisions. Unfortunately, accurate prediction of neurological outcomes is difficult (2, 3). There is substantial variability in clinicians’ perceptions regarding the prognosis of individual patients (4). Physicians are sometimes more pessimistic than is actually justified by available clinical information (4, 5). This may lead to premature recommendations to limit lifesustaining interventions, which in turn may produce self-fulfilling prophecies (5, 6). Outcomes in neurocritical care have improved over time, which may make older prognostic literature less reliable (7). These factors contribute to marked differences in practices related to withdrawal of life-sustaining interventions, even when the severity of brain injury is taken into account (8). It is very likely that this variability also contributes to sizable inter-center differences in donation and transplantation rates. Prognostic uncertainty should be acknowledged and disclosed. One strategy that may help safeguard against inappropriately pessimistic information is for intensivists to seek an independent second opinion, especially before discussions concerning limitations in life-sustaining interventions. Clinicians with particular experience in the care of critically ill neurological patients, such as neurointensivists, are especially well suited to provide such consultations (9). Second, patients’ willingness to become organ donors should never influence the decision to discontinue life-sustaining interventions. The authors hint at this when they recommend that discussions regarding withdrawal of life-sustaining interventions should occur before discussions of organ donation. Patients who have registered their intent to be organ donors have generally only done so in the event that there is no reasonable hope of a favorable recovery. This should not be construed as a reason to sway surrogate decision makers or clinicians toward earlier withdrawal of life-sustaining interventions when the prognosis remains unclear. Third, in order for organs to be recovered and transplanted, “warm ischemic” time must be limited. If the interval between withdrawal of life-sustaining interventions and cardiac arrest is “long”—most organ donation programs consider 60 to 120 minutes as the maximum acceptable interval—then DCD ceases to be an option. Intensivists are well aware that this time interval can be modified by administration of opiates and sedatives. This creates the uncomfortable possibility that the chance of becoming an organ donor is influenced by how aggressively the intensive care or palliative care teams administer these drugs. Use of opiates is necessary and appropriate at the end of life. However, dosing should not differ from that of patients who are not candidates for DCD. Having a well-developed protocol, in which administration of drugs is guided by objective criteria rather than the preferences of individual physicians or nurses, is a helpful safeguard (10). Finally, for the above-mentioned reasons, we are concerned about the tendency of some regulatory and organ procurement

American Journal of Respiratory and Critical Care Medicine Volume 189 Number 4 | February 15 2014

CORRESPONDENCE agencies to consider the absolute number of donors (“donors per million” [DPM]) as a “quality,” “accountability,” or “performance” measure. This practice has the potential to apply inappropriate and coercive pressure on critical care professionals. Worse, it risks discriminating against brain-injured patients by indirectly suggesting that life-sustaining interventions should be withdrawn more often. Modern, high-quality care of severely brain-injured patients may actually reduce the number of deceased organ donors (7, 11). It is conceivable that some jurisdictions could have relatively high DPM rates, but also higher rates of withdrawal and higher mortality in neurocritical care patients (8). A more meaningful metric would be one in which DPM is adjusted for appropriate brain injury quality-of-care indicators. We believe that every center that performs DCD should have policies and protocols in place that carefully address these and other ethical considerations with DCD, and do not inappropriately overemphasize the absolute number of organ donors as a measure of “success.” n Author disclosures are available with the text of this letter at www.atsjournals.org. Andreas H. Kramer, M.D., M.Sc. University of Calgary Calgary, Alberta, Canada and Southern Alberta Organ and Tissue Donation Program Calgary, Alberta, Canada David A. Zygun, M.D., M.Sc. University of Alberta Edmonton, Alberta, Canada and Alberta Health Services Alberta, Canada

References 1. Gries CJ, White DB, Truog RD, Dubois J, Cosio CC, Dhanani S, Chan KM, Corris P, Dark J, Fulda G, et al.; American Thoracic Society Health Policy

Correspondence

Committee. An official American Thoracic Society/International Society for Heart and Lung Transplantation/Society of Critical Care Medicine/Association of Organ and Procurement Organizations/United Network of Organ Sharing Statement: ethical and policy considerations in organ donation after circulatory determination of death. Am J Respir Crit Care Med 2013;188:103–109. 2. Finley Caulfield A, Gabler L, Lansberg MG, Eyngorn I, Mlynash M, Buckwalter MS, Venkatasubramanian C, Wijman CA. Outcome prediction in mechanically ventilated neurologic patients by junior neurointensivists. Neurology 2010;74:1096–1101. 3. Stevens RD, Sutter R. Prognosis in severe brain injury. Crit Care Med 2013;41:1104–1123. 4. Turgeon AF, Lauzier F, Burns KE, Meade MO, Scales DC, Zarychanski R, Moore L, Zygun DA, McIntyre LA, Kanji S, et al.; Canadian Critical Care Trials Group. Determination of neurologic prognosis and clinical decision making in adult patients with severe traumatic brain injury: a survey of Canadian intensivists, neurosurgeons, and neurologists. Crit Care Med 2013;41:1086–1093. 5. Becker KJ, Baxter AB, Cohen WA, Bybee HM, Tirschwell DL, Newell DW, Winn HR, Longstreth WT Jr. Withdrawal of support in intracerebral hemorrhage may lead to self-fulfilling prophecies. Neurology 2001;56:766–772. 6. Hemphill JC III, Newman J, Zhao S, Johnston SC. Hospital usage of early do-not-resuscitate orders and outcome after intracerebral hemorrhage. Stroke 2004;35:1130–1134. 7. Kramer AH, Zygun DA. Declining mortality in neurocritical care patients: a cohort study in Southern Alberta over eleven years. Can J Anaesth 2013;60:966–975. 8. Turgeon AF, Lauzier F, Simard JF, Scales DC, Burns KE, Moore L, Zygun DA, Bernard F, Meade MO, Dung TC, et al.; Canadian Critical Care Trials Group. Mortality associated with withdrawal of life-sustaining therapy for patients with severe traumatic brain injury: a Canadian multicentre cohort study. CMAJ 2011;183:1581–1588. 9. Kramer AH, Zygun DA. Do neurocritical care units save lives? Measuring the impact of specialized ICUs. Neurocrit Care 2011;14:329–333. 10. Treece PD, Engelberg RA, Crowley L, Chan JD, Rubenfeld GD, Steinberg KP, Curtis JR. Evaluation of a standardized order form for the withdrawal of life support in the intensive care unit. Crit Care Med 2004;32:1141–1148. 11. Kramer AH, Zygun DA, Doig CJ, Zuege DJ. Incidence of neurological death in brain-injured patients: a cohort study in a Canadian health region. CMAJ 2013;185:E838–E845.

Copyright © 2014 by the American Thoracic Society

505

Donation after circulatory determination of death: we need to respect and protect brain-injured patients.

Donation after circulatory determination of death: we need to respect and protect brain-injured patients. - PDF Download Free
428KB Sizes 0 Downloads 0 Views