| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Guest Access | Sign In via User Name/Password
|
|
|
|||||||
Guest Access | Sign In via User Name/Password |
|||||||||
Dr. Nichols is Assistant Professor of Medicine, Dr. Maziarz is Associate Professor of Medicine, Microbiology and Immunology, and Dr. Haupt is Professor, Department of Medicine at Oregon Health Sciences University.
Correspondence to: Dane Nichols, MD, Division of Pulmonary and Critical Care Medicine, Oregon Health Sciences University, UHS8Q, 3181 SW Sam Jackson Park Rd, Portland, OR 97221
Respiratory failure in the context of bone marrow transplant (BMT) is distressingly common and is associated with low long-term survival rates among patients requiring mechanical ventilation. Although disparate processes may lead to invasive ventilatory support, when multiorgan system dysfunction supervenes survival may be impossible. The bleak experience in this population has lead some authors to suggest early withdrawal of support in the presence of key organ dysfunction or, in the extreme view, withholding the option of mechanical ventilation altogether.1 2
In this issue of CHEST (see page 1012), Dr. Shorr and colleagues provide important lessons for those of us who routinely manage the critical care aspects of patients undergoing hematopoietic stem cell transplant. First, not all transplanted patients with respiratory failure can be expected to succumb. Second, in the select, low-risk population of autologous stem cell transplant, respiratory failure requiring mechanical ventilation is still encountered relatively frequently (10.7%). Third, the survival rate in the subset of patients with respiratory failure posttransplant falls within a range that we see for many other diseases that are routinely managed in ICUs, such as sepsis-related ARDS and anoxic encephalopathy.3 4 5
Recent case reports and observational studies support the conclusion that the prognosis for many of these patients is significantly improved over that reported in the 1980s and early 1990s. Survival rates for intubated bone marrow and stem cell transplant patients may now be as high as 16 to 19% overall.1 6 7 Within certain groups, such as those with engraftment syndrome, survival may be considerably higher. Lee et al8 reported 68% survival in patients described as having ARDS following engraftment of autologous cells when treated with high-dose steroids.
What factors are responsible for this trend toward improved survival? New molecular diagnostics and more effective prophylaxis leading to lower rates of viral and fungal pneumonias may have contributed to better outcomes. Reduced toxicity of conditioning regimens culminating in less severe expression of the idiopathic pneumonia syndrome may be playing a role as well.7 9 While difficult to quantitate, it is also quite likely that experience with this group of patients has played a role in increasing our ability to recognize and effectively manage potentially lethal complications.
It is, therefore, incumbent on critical care practitioners to aggressively support these patients in the early phase of respiratory failure, to diligently attempt to establish an etiology, and to avoid contributing to the climate of pessimism that frequently surrounds their ICU care. This can best be achieved by collaboratively managing patients with the transplant team. It is important to recall that many of these patients do not progress to severe respiratory failure and often can be managed by way of noninvasive mask ventilation. Treatable diagnoses such as capillary leak associated with engraftment, congestive heart failure, and pulmonary hemorrhage also represent opportunities for therapeutic intervention.
Despite the improved outlook, 
80% of patients undergoing
hematopoietic stem cell transplant who develop respiratory failure will
not survive their ICU or hospital stay. In those who progress,
it is our obligation to limit treatment ... in those patients who
are overwhelmed by their disease. The appropriate timing for
withholding or withdrawal of support is probably the most contentious
issue surrounding the care of these patients. Our ability to
prognosticate early in the course of an ICU stay is hampered by the
poor performance of standard scoring systems such as the
simplified acute physiology score II, Mortality Probability
Model II, and acute physiology and chronic health evaluation
II.5
Although they are more accurate (and are difficult to
apply), other models specific to oncology patients have, at present,
unacceptably wide confidence intervals.6
10
Guidelines proposed by Rubenfeld and Crawford1 provide a reasonable approach for the ICU practitioner who is dealing with this high-risk population. A period of mechanical ventilation should generally be offered to all patients who are requesting this level of support. This is continued until progressive organ dysfunction and/or ongoing vasopressor requirements lead to the conclusion that further aggressive treatment would be futile. Certain combinations of organ involvement in particular carry a very low probability of survival and may allow for the early limitation of care. In the Seattle experience, where the majority of patients were allogeneic marrow recipients, no patient survived with the combination of lung injury, hepatic and renal failure, and hypotension necessitating vasopressor use.1
With the availability of such data, it is instructive to review what impact antecedent knowledge and awareness of these outcome measures has on physician performance and patient preference. Paz and colleagues11 developed an educational program in their institution that stressed the dismal survival rates for intubated BMT recipients. ICU admission rates were not significantly changed over time despite general acceptance of the data. What proved even more striking was the self-reported timing of discussions regarding ICU care. Approximately one third of the attending oncologists did not raise the issue of efficacy of intensive care in the pretransplant or immediate posttransplant period.
Studies in other groups, such as the elderly, suggest that conveying this kind of information is important in guiding patient preferences.12 However, the same may not hold true in the BMT population. Reports dealing with informed consent in BMT patients suggest that the survival imperative and trust in their physician carry more weight in the decision-making process than risk and outcome data.13 14 Clearly, during this time of emotional turmoil and physical stress, asking patients and their families to provide direction for their future care in a disinterested, objective manner is unrealistic.
So what should we consider for the future? (1) Patients must be encouraged to generate advanced directives. (2) Informed consent should include intubation outcome data based on current evidence. (3) Proactive collaboration between the transplant team and ICU service must be established early in the ICU stay. (4) Physicians need to stay abreast of the changing spectrum of respiratory disease in this population, and they must move quickly to identify processes for which treatment can be expected to lead to reasonable survival rates. Finally, when uncertainty exists over the direction that care should take, decisions should be guided by probability estimates that are undertaken in a climate of understanding and compassion.
References
This article has been cited by other articles:
|
|
 |
|
  A. O. Soubani, E. Kseibi, J. J. Bander, J. L. Klein, G. Khanchandani, H. P. Ahmed, and J. A. Guzman Outcome and Prognostic Factors of Hematopoietic Stem Cell Transplantation Recipients Admitted to a Medical ICU Chest, November 1, 2004; 126(5): 1604 - 1611. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Rano, C. Agusti, N. Benito, M. Rovira, J. Angrill, T. Pumarola, and A. Torres Prognostic Factors of Non-HIV Immunocompromised Patients With Pulmonary Infiltrates* Chest, July 1, 2002; 122(1): 253 - 261. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. B. Bach, D. Schrag, D. M. Nierman, D. Horak, P. White Jr, J. W. Young, and J. S. Groeger Identification of poor prognostic features among patients requiring mechanical ventilation after hematopoietic stem cell transplantation Blood, December 1, 2001; 98(12): 3234 - 3240. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
