Incidence and Outcomes of Acute Lung Injury
http://www.100md.com
《新英格兰医药杂志》
To the Editor: Rubenfeld and colleagues (Oct. 20 issue)1 discuss the incidence and outcomes of acute lung injury in a large, population-based cohort study. The authors provide data on the known risk factors of acute lung injury and convincingly suggest that their population cohort was representative of the U.S. population as a whole. We are surprised, however, that they did not include data that address characteristics that might protect patients against the development of acute lung injury.
As previously reported by Moss and colleagues, the incidence of and mortality from acute respiratory distress syndrome are reduced in patients with diabetes mellitus.2 Experimental data published more recently3 support these data on humans. Although the mechanisms by which diabetes provides "protection" against acute lung injury are not well understood, leptin resistance may play an important role. In future studies, inclusion of data about patient characteristics that either improve or worsen the outcomes of acute lung injury might facilitate the development of novel strategies to improve the care of patients with this deadly disease.
Gokhan M. Mutlu, M.D.
G.R. Scott Budinger, M.D.
Northwestern University Feinberg School of Medicine
Chicago, IL 60611
g-mutlu@northwestern.edu
References
Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N Engl J Med 2005;353:1685-1693.
Moss M, Guidot DM, Steinberg KP, et al. Diabetic patients have a decreased incidence of acute respiratory distress syndrome. Crit Care Med 2000;28:2187-2192.
Barazzone-Argiroffo C, Muzzin P, Donati YR, Kan CD, Aubert ML, Piguet PF. Hyperoxia increases leptin production: a mechanism mediated through endogenous elevation of corticosterone. Am J Physiol Lung Cell Mol Physiol 2001;281:L1150-L1156.
To the Editor: Rubenfeld et al. demonstrated an adjusted incidence of acute lung injury of 86.2 per 100,000 person-years, with an in-hospital mortality rate of 38.5 percent. The most common risk factor for acute lung injury was severe sepsis, with a suspected pulmonary source of 46 percent. It is well known that acute lung injury resulting from smoke inhalation and pneumonia has additive effects on mortality in patients with burns. Inhalation injury alone increases mortality by 20 percent and pneumonia increases the rate by 40 percent, with a maximal increase of approximately 60 percent when both are present.1 Rubenfeld et al. included the Harborview Medical Center (382 patients) in their study, which houses one of the biggest burn centers in the United States. In the Methods section of their article, the inhalation injury is mentioned as one source of acute lung injury, but there is no mention of this important class of patients as a subgroup in the results. Progressive improvement in burn care has been made,2 and it would have been appropriate for the authors to compare their mortality rate with that in patients with burns and smoke-inhalation injuries.
Marc O. Maybauer, M.D., Ph.D.
Dirk M. Maybauer, M.D., Ph.D.
David N. Herndon, M.D.
University of Texas Medical Branch
Galveston, TX 77555
momaybau@utmb.edu
References
Shirani KZ, Pruitt BA Jr, Mason AD Jr. The influence of inhalation injury and pneumonia on burn mortality. Ann Surg 1987;205:82-87.
Pruitt BA Jr, Goodwin CW, Mason AD Jr. Epidemiological, demographic, and outcome characteristics of burn injury. In: Herndon DN, ed. Total burn care. 2nd ed. New York: W.B. Saunders, 2002:16-30.
The authors reply: Drs. Mutlu and Budinger inquire about diagnoses, such as diabetes mellitus, that might prevent acute lung injury. Since the King County Lung Injury Project (KCLIP) was designed to study the incidence and outcomes of patients with acute lung injury, limited information was collected from patients without this diagnosis. Therefore, this cohort cannot be used to address the question they raise.
The question asked by Dr. Maybauer and colleagues supports the importance of population-based epidemiology of critical illness syndromes. During the study period, there were 30 patients with burns treated at Harborview Medical Center who met the criteria for acute lung injury; however, 26 (87 percent) of these patients lived outside of King County and therefore did not contribute to the population incidence. Clinicians who practice in academic centers and studies restricted to these centers may overestimate the incidence of diseases on the basis of the distribution of cases referred to specialized centers. Respiratory complications of inhalation and thermal injury are associated with high morbidity and mortality; however, data from KCLIP suggest that the overall contribution of these risk factors to the population incidence of acute lung injury is small.
Gordon D. Rubenfeld, M.D.
Ellen Caldwell, M.S.
Leonard D. Hudson, M.D.
University of Washington
Seattle, WA 98104
nodrog@u.washington.edu
As previously reported by Moss and colleagues, the incidence of and mortality from acute respiratory distress syndrome are reduced in patients with diabetes mellitus.2 Experimental data published more recently3 support these data on humans. Although the mechanisms by which diabetes provides "protection" against acute lung injury are not well understood, leptin resistance may play an important role. In future studies, inclusion of data about patient characteristics that either improve or worsen the outcomes of acute lung injury might facilitate the development of novel strategies to improve the care of patients with this deadly disease.
Gokhan M. Mutlu, M.D.
G.R. Scott Budinger, M.D.
Northwestern University Feinberg School of Medicine
Chicago, IL 60611
g-mutlu@northwestern.edu
References
Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N Engl J Med 2005;353:1685-1693.
Moss M, Guidot DM, Steinberg KP, et al. Diabetic patients have a decreased incidence of acute respiratory distress syndrome. Crit Care Med 2000;28:2187-2192.
Barazzone-Argiroffo C, Muzzin P, Donati YR, Kan CD, Aubert ML, Piguet PF. Hyperoxia increases leptin production: a mechanism mediated through endogenous elevation of corticosterone. Am J Physiol Lung Cell Mol Physiol 2001;281:L1150-L1156.
To the Editor: Rubenfeld et al. demonstrated an adjusted incidence of acute lung injury of 86.2 per 100,000 person-years, with an in-hospital mortality rate of 38.5 percent. The most common risk factor for acute lung injury was severe sepsis, with a suspected pulmonary source of 46 percent. It is well known that acute lung injury resulting from smoke inhalation and pneumonia has additive effects on mortality in patients with burns. Inhalation injury alone increases mortality by 20 percent and pneumonia increases the rate by 40 percent, with a maximal increase of approximately 60 percent when both are present.1 Rubenfeld et al. included the Harborview Medical Center (382 patients) in their study, which houses one of the biggest burn centers in the United States. In the Methods section of their article, the inhalation injury is mentioned as one source of acute lung injury, but there is no mention of this important class of patients as a subgroup in the results. Progressive improvement in burn care has been made,2 and it would have been appropriate for the authors to compare their mortality rate with that in patients with burns and smoke-inhalation injuries.
Marc O. Maybauer, M.D., Ph.D.
Dirk M. Maybauer, M.D., Ph.D.
David N. Herndon, M.D.
University of Texas Medical Branch
Galveston, TX 77555
momaybau@utmb.edu
References
Shirani KZ, Pruitt BA Jr, Mason AD Jr. The influence of inhalation injury and pneumonia on burn mortality. Ann Surg 1987;205:82-87.
Pruitt BA Jr, Goodwin CW, Mason AD Jr. Epidemiological, demographic, and outcome characteristics of burn injury. In: Herndon DN, ed. Total burn care. 2nd ed. New York: W.B. Saunders, 2002:16-30.
The authors reply: Drs. Mutlu and Budinger inquire about diagnoses, such as diabetes mellitus, that might prevent acute lung injury. Since the King County Lung Injury Project (KCLIP) was designed to study the incidence and outcomes of patients with acute lung injury, limited information was collected from patients without this diagnosis. Therefore, this cohort cannot be used to address the question they raise.
The question asked by Dr. Maybauer and colleagues supports the importance of population-based epidemiology of critical illness syndromes. During the study period, there were 30 patients with burns treated at Harborview Medical Center who met the criteria for acute lung injury; however, 26 (87 percent) of these patients lived outside of King County and therefore did not contribute to the population incidence. Clinicians who practice in academic centers and studies restricted to these centers may overestimate the incidence of diseases on the basis of the distribution of cases referred to specialized centers. Respiratory complications of inhalation and thermal injury are associated with high morbidity and mortality; however, data from KCLIP suggest that the overall contribution of these risk factors to the population incidence of acute lung injury is small.
Gordon D. Rubenfeld, M.D.
Ellen Caldwell, M.S.
Leonard D. Hudson, M.D.
University of Washington
Seattle, WA 98104
nodrog@u.washington.edu