The
n e w e ng l a n d j o u r na l
3. Liu X, Gao N, Li M, et al. Elevated levels of CD4(+)CD25(+)
FoxP3(+) T cells in systemic sclerosis patients contribute to the secretion of IL-17 and immunosuppression dysfunction. PLoS One 2013;8(6):e64531. 4. Radstake TR, Gorlova O, Rueda B, et al. Genome-wide association study of systemic sclerosis identifies CD247 as a new susceptibility locus. Nat Genet 2010;42:426-9.
of
m e dic i n e
5. Lundholm M, Mayans S, Motta V, Löfgren-Burström A,
Danska J, Holmberg D. Variation in the Cd3 zeta (Cd247) gene correlates with altered T cell activation and is associated with autoimmune diabetes. J Immunol 2010;184:5537-44.
DOI: 10.1056/NEJMc1402401
Distracted Driving and Crash Risk To the Editor: Klauer et al. (Jan. 2 issue)1 report 31 crashes among 42 newly licensed drivers and 42 crashes among 109 experienced drivers who were operating cars equipped with vehicle sensors and other monitoring equipment during an 18-month period in Virginia. This equates to a 49% crash rate per year for novice drivers (mean age, 16.4 years) and a 26% rate for experienced drivers. In 2007, the Virginia Department of Motor Vehicles reported 145,405 crashes among 5,436,825 licensed drivers; the overall crash rate was 2.7% per year.2 Despite increasing cell-phone use, the crash rate declined to 2.2% per year in 2012.3 The crash rates that were reported by Klauer et al. are 10 to 20 times as high as the Virginia statewide statistics. This disparity is not explained. Most people would drive more carefully if video cameras and sensors were installed on their cars. Were participants encouraged to drive normally and reflect the practices used by the general population or to push the limits of driving while distracted to the limit? Charles Mick, M.D. Pioneer Spine and Sports Northampton, MA
[email protected]
Richard A. Young, Ph.D.
No potential conflict of interest relevant to this letter was reported. 1. Klauer SG, Guo F, Simons-Morton BG, Ouimet MC, Lee SE,
Dingus TA. Distracted driving and risk of road crashes among novice and experienced drivers. N Engl J Med 2014;370:54-9. 2. 2007 Virginia traffic crash facts. Richmond: Virginia Department of Motor Vehicles (http://www.dmv.virginia.gov/safety/ #crash_data/crash_facts/crash_facts_07.asp). 3. 2012 Virginia traffic crash facts. Richmond: Virginia Department of Motor Vehicles (http://www.dmv.virginia.gov/safety/ crash_data/crash_facts/crash_facts_12.pdf). DOI: 10.1056/NEJMc1401241
To the Editor: Novice drivers may have elevated relative risks of crashes or near-crashes associated with involvement in secondary tasks, as compared with experienced drivers. However, appar1564
ent differences between novice and experienced drivers in the study by Klauer et al. may alternatively reflect confounding effects of age, a major limitation that should have been acknowledged or controlled for by contrasting novice adolescent drivers with novice adult drivers. Other potential confounders that were not addressed in this study include traffic conditions, nearness to an intersection, and time of day.1 The authors estimated relative risks associated with talking on the phone to be near 1, in contrast to estimates of a relative risk of nearly 4 in previous studies without video recordings.2,3 They attribute this major discrepancy to that fact that previous studies did not differentiate between dialing (an activity associated with higher risk) and talking. However, previous studies used billing records, in which outbound time stamps are recorded only after a caller finishes dialing, hits “send,” the call is successfully routed, and the called party answers. There is no billing record if a crash occurs during dialing or before the called party answers. If a crash occurs during talking, then talking is the potential proximate cause, not dialing. Wayne State University School of Medicine Detroit, MI
[email protected] Dr. Young reports having received financial support from automotive companies on research projects unrelated to this letter. No other potential conflict of interest relevant to this letter was reported. 1. Young RA. Cell phone conversation and automobile crashes:
relative risk is near 1, not 4. Presented at the 3rd International Conference on Driver Distraction and Inattention, Gothenburg, Sweden, September 4–6, 2013. 2. Redelmeier DA, Tibshirani RJ. Association between cellulartelephone calls and motor vehicle collisions. N Engl J Med 1997; 336:453-8. 3. McEvoy SP, Stevenson MR, McCartt AT, et al. Role of mobile phones in motor vehicle crashes resulting in hospital attendance: a case-crossover study. BMJ 2005;331:428-30. DOI: 10.1056/NEJMc1401241
n engl j med 370;16 nejm.org april 17, 2014
The New England Journal of Medicine Downloaded from nejm.org at STOCKHOLMS UNIVERSTITETSBIBL on August 11, 2015. For personal use only. No other uses without permission. Copyright © 2014 Massachusetts Medical Society. All rights reserved.
correspondence
To the Editor: Klauer et al. report that the risk of crashes increased with distracted driving among young, novice drivers, as compared with the risk in older, experienced drivers between the ages of 18 and 72 years (mean age, 36). However, in a previous study,1 as compared with adult drivers between the ages of 40 and 49 years, drivers between the ages of 65 and 69 years had a 30% higher risk of being involved in a fatal crash, and drivers who were 85 years of age or older had a risk that was 3 to 4 times as high. Thus, in countries in which older persons are constituting an increasingly high percentage of the population (e.g., Italy, Japan, and Germany), the number of elderly drivers is projected to sharply increase the rate of numerous challenges to public safety. Driving requires the integration of high-level cognition, vision, and motor function.2 Conversely, many physical and cognitive changes affect driving among the elderly, such as slower reaction time, hearing and vision problems, decreased ability to focus, and medical problems, including age-associated cognitive decline and the use of drugs affecting cognitive performance.3 Thus, although Klauer et al. note particular risks of distracted driving among young, inexperienced drivers, elderly drivers over the age of 75 (who were not included in the study) may be another group at particular risk, increasing the risk of morbidity and mortality of their passengers and other people on the road.4 Virginia Boccardi, M.D. Giuseppe Paolisso, M.D., Ph.D.
are a major concern, we often ignore a much more common risk factor: the use of cell phones while driving. The article by Klauer et al. and the accompanying Perspective article by Jones1 point out both the risks and the role of the physician. Since the behavior of physicians may influence patients, we should take a lead in this area. It may be difficult to modify physician behavior, since doctors are already being distracted with the use of smartphones during patient care, and there is the rationalization that we must use our free time in the car to return calls from patients. However, I propose that physicians should not speak to patients while they (or we) are using a cell phone while driving. If we call patients and they are driving, we should state that we will be happy to speak with them at a time when they are not distracted. Jonathan M. Silver, M.D. New York University School of Medicine New York, NY
[email protected] No potential conflict of interest relevant to this letter was reported. 1. Jones DS. Doctors and the dangers of driving. N Engl J Med
2014;370:8-11.
DOI: 10.1056/NEJMc1401241
The authors reply: Mick raises a concern that the rates of crashes and near-crashes in our study appear to be higher than those in published statistics. Crash databases typically include only severe crashes that are generated by police reports. In naturalistic driving studies (NDS), the conSecond University of Naples Naples, Italy tinuous, high-resolution data allow for the [email protected] tion of serious collisions, minor crashes, and nearNo potential conflict of interest relevant to this letter was recrashes, providing a comprehensive measure of ported. risk.1 Thus, the crash rate of the study population 1. Preusser DF, Williams AF, Ferguson SA, Ulmer RG, Weinstein HB. Fatal crash risk for older drivers at intersections. Accid is not higher than that in the general teenage Anal Prev 1998;30:151-9. driving population. However, our findings indi2. Sherman FT. Driving: the ultimate IADL. Geriatrics 2006; cate that participating teenagers were involved in 61:9-10. 3. Classen S, Horgas A, Awadzi K, Messinger-Rapport B, Shecht more “loss of control” events than was previousman O, Joo Y. Clinical predictors of older driver performance on a ly known. standardized road test. Traffic Inj Prev 2008;9:456-62. Regarding the comment by Young with re4. Braver ER, Trempel RE. Are older drivers actually at higher spect to age versus experience: we purposefully risk of involvement in collisions resulting in deaths or non-fatal injuries among their passengers and other road users? Inj Prev selected a target population of teenagers who 2004;10:27-32. had had their licenses for 3 weeks or less. Our DOI: 10.1056/NEJMc1401241 study was not designed to address the effects of age versus experience on distracted driving. The To the Editor: Physicians have an important results were analyzed and presented separately role in preventing disease, including traumatic for the novice drivers and the more experienced brain injury. Although concussions from sports drivers. Young also expresses concern about
n engl j med 370;16 nejm.org april 17, 2014
1565
The New England Journal of Medicine Downloaded from nejm.org at STOCKHOLMS UNIVERSTITETSBIBL on August 11, 2015. For personal use only. No other uses without permission. Copyright © 2014 Massachusetts Medical Society. All rights reserved.
The
n e w e ng l a n d j o u r na l
potential confounding in our study. Since this was an observational study, we acknowledge this possibility. However, we believe that random sampling of noncrash road segments, as we used for our control, minimizes the chance that such confounders substantially influenced the results. The continuous video collected by NDS allows for the precise separation of talking on a cell phone with visual–manual tasks associated with cell-phone use, which effectively averts any potential information bias associated with cell-phone use while driving. Young’s argument that previous research that was conducted on the basis of cell-phone records was limited to the risk associated with talking on but not with dialing a cell phone has been debated previously.2 In addition, others have reported that both the beginning and ending of cell-phone conversations, which are not reflected in billing records, require risky visual–manual tasks.3 Contributing factors leading to crashes typically unfold over time. Since the moment when a crash occurs is difficult to match precisely to time stamps in cell-phone records, the determination of a proximate cause is not possible on the basis of crash reports and cell-phone records. As noted by Boccardi and Paolisso, more research should be done on the effects of secondarytask involvement on the risk of crashes or nearcrashes for drivers of all ages. We also argue that more research on the effects of driver distraction should be conducted on specialty popu-
of
m e dic i n e
lations of drivers, including emergency responders (e.g., police officers and ambulance drivers), as well as physicians who are using their vehicle as a mobile office. As Silver notes, complex conversation is a distraction for drivers, but the effect of this type of conversation is not yet fully understood. Sheila G. Klauer, Ph.D. Feng Guo, Ph.D. Virginia Tech Transportation Institute Blacksburg, VA
[email protected]
Bruce G. Simons-Morton, Ed.D., M.P.H. Eunice Kennedy Shriver National Institute of Child Health and Human Development Bethesda, MD Since publication of their article, Dr. Klauer’s disclosure form has been updated to include grant support from the automotive industry and Dr. Guo’s disclosure form has been updated to include grant support from an accident-management company. The disclosure forms of Drs. Lee and Dingus, coauthors, have also been updated to include grant support from the automotive industry. No further potential conflict of interest relevant to this letter was reported. 1. Dingus TA, Klauer SG, Neale VL, et al. The 100-Car Natural-
istic Driving Study, Phase II — results of the 100-car field experiment. Washington, DC: National Highway Traffic Safety Administration, 2006 (http://www.distraction.gov/research/pdf-files/ the-100-car-naturalistic-driving-study.pdf). 2. Mittleman MA, Maclure M, Mostofsky E. Cell phone use and crash risk. Epidemiology 2012;23:647-50. 3. Fitch GM, Soccolich SA, Guo F, et al. The impact of handheld and hands-free cell phone use on driving performance and safety-critical event risk. Washington, DC: National Highway Traffic Safety Administration, 2013 (http://www.distraction.gov/ download/811757.pdf). DOI: 10.1056/NEJMc1401241
Sedation and Delirium in Intensive Care To the Editor: We agree with Reade and Finfer (Jan. 30 issue)1 that prevention of delirium in patients in the intensive care unit (ICU) is clearly preferable to treatment after the fact. Reduction or prevention of sleep deprivation may be an additional measure to reduce the risk of delirium in the ICU.2 Noise, light, and other factors may be associated with poor sleep quality. A reduction in these factors and promotion of positive sleep-hygiene behaviors are associated with a reduction in the incidence of delirium or coma.3 Because most sedatives degrade sleep architecture, their use may actually increase the risk of delirium, rather than reduce it.2 In addition to minimizing the use of sedative agents, other therapies warrant mention. Critically ill patients 1566
have a documented loss of a normal circadian rhythm associated with melatonin secretion.4 Exogenous melatonin may be an effective countermeasure to reduce abnormalities in sleep architecture, and preliminary data to this effect are encouraging.5 Data are lacking from studies to evaluate the effects of melatonin on sleep, delirium, and acute brain dysfunction in critically ill patients. We hope that future studies of delirium in the ICU include this therapy. Alexander H. Flannery, Pharm.D. Kevin W. Hatton, M.D. Barbara Phillips, M.D., M.S.P.H. University of Kentucky HealthCare Lexington, KY [email protected]
n engl j med 370;16 nejm.org april 17, 2014
The New England Journal of Medicine Downloaded from nejm.org at STOCKHOLMS UNIVERSTITETSBIBL on August 11, 2015. For personal use only. No other uses without permission. Copyright © 2014 Massachusetts Medical Society. All rights reserved.
n e w e ng l a n d j o u r na l
3. Liu X, Gao N, Li M, et al. Elevated levels of CD4(+)CD25(+)
FoxP3(+) T cells in systemic sclerosis patients contribute to the secretion of IL-17 and immunosuppression dysfunction. PLoS One 2013;8(6):e64531. 4. Radstake TR, Gorlova O, Rueda B, et al. Genome-wide association study of systemic sclerosis identifies CD247 as a new susceptibility locus. Nat Genet 2010;42:426-9.
of
m e dic i n e
5. Lundholm M, Mayans S, Motta V, Löfgren-Burström A,
Danska J, Holmberg D. Variation in the Cd3 zeta (Cd247) gene correlates with altered T cell activation and is associated with autoimmune diabetes. J Immunol 2010;184:5537-44.
DOI: 10.1056/NEJMc1402401
Distracted Driving and Crash Risk To the Editor: Klauer et al. (Jan. 2 issue)1 report 31 crashes among 42 newly licensed drivers and 42 crashes among 109 experienced drivers who were operating cars equipped with vehicle sensors and other monitoring equipment during an 18-month period in Virginia. This equates to a 49% crash rate per year for novice drivers (mean age, 16.4 years) and a 26% rate for experienced drivers. In 2007, the Virginia Department of Motor Vehicles reported 145,405 crashes among 5,436,825 licensed drivers; the overall crash rate was 2.7% per year.2 Despite increasing cell-phone use, the crash rate declined to 2.2% per year in 2012.3 The crash rates that were reported by Klauer et al. are 10 to 20 times as high as the Virginia statewide statistics. This disparity is not explained. Most people would drive more carefully if video cameras and sensors were installed on their cars. Were participants encouraged to drive normally and reflect the practices used by the general population or to push the limits of driving while distracted to the limit? Charles Mick, M.D. Pioneer Spine and Sports Northampton, MA
[email protected]
Richard A. Young, Ph.D.
No potential conflict of interest relevant to this letter was reported. 1. Klauer SG, Guo F, Simons-Morton BG, Ouimet MC, Lee SE,
Dingus TA. Distracted driving and risk of road crashes among novice and experienced drivers. N Engl J Med 2014;370:54-9. 2. 2007 Virginia traffic crash facts. Richmond: Virginia Department of Motor Vehicles (http://www.dmv.virginia.gov/safety/ #crash_data/crash_facts/crash_facts_07.asp). 3. 2012 Virginia traffic crash facts. Richmond: Virginia Department of Motor Vehicles (http://www.dmv.virginia.gov/safety/ crash_data/crash_facts/crash_facts_12.pdf). DOI: 10.1056/NEJMc1401241
To the Editor: Novice drivers may have elevated relative risks of crashes or near-crashes associated with involvement in secondary tasks, as compared with experienced drivers. However, appar1564
ent differences between novice and experienced drivers in the study by Klauer et al. may alternatively reflect confounding effects of age, a major limitation that should have been acknowledged or controlled for by contrasting novice adolescent drivers with novice adult drivers. Other potential confounders that were not addressed in this study include traffic conditions, nearness to an intersection, and time of day.1 The authors estimated relative risks associated with talking on the phone to be near 1, in contrast to estimates of a relative risk of nearly 4 in previous studies without video recordings.2,3 They attribute this major discrepancy to that fact that previous studies did not differentiate between dialing (an activity associated with higher risk) and talking. However, previous studies used billing records, in which outbound time stamps are recorded only after a caller finishes dialing, hits “send,” the call is successfully routed, and the called party answers. There is no billing record if a crash occurs during dialing or before the called party answers. If a crash occurs during talking, then talking is the potential proximate cause, not dialing. Wayne State University School of Medicine Detroit, MI
[email protected] Dr. Young reports having received financial support from automotive companies on research projects unrelated to this letter. No other potential conflict of interest relevant to this letter was reported. 1. Young RA. Cell phone conversation and automobile crashes:
relative risk is near 1, not 4. Presented at the 3rd International Conference on Driver Distraction and Inattention, Gothenburg, Sweden, September 4–6, 2013. 2. Redelmeier DA, Tibshirani RJ. Association between cellulartelephone calls and motor vehicle collisions. N Engl J Med 1997; 336:453-8. 3. McEvoy SP, Stevenson MR, McCartt AT, et al. Role of mobile phones in motor vehicle crashes resulting in hospital attendance: a case-crossover study. BMJ 2005;331:428-30. DOI: 10.1056/NEJMc1401241
n engl j med 370;16 nejm.org april 17, 2014
The New England Journal of Medicine Downloaded from nejm.org at STOCKHOLMS UNIVERSTITETSBIBL on August 11, 2015. For personal use only. No other uses without permission. Copyright © 2014 Massachusetts Medical Society. All rights reserved.
correspondence
To the Editor: Klauer et al. report that the risk of crashes increased with distracted driving among young, novice drivers, as compared with the risk in older, experienced drivers between the ages of 18 and 72 years (mean age, 36). However, in a previous study,1 as compared with adult drivers between the ages of 40 and 49 years, drivers between the ages of 65 and 69 years had a 30% higher risk of being involved in a fatal crash, and drivers who were 85 years of age or older had a risk that was 3 to 4 times as high. Thus, in countries in which older persons are constituting an increasingly high percentage of the population (e.g., Italy, Japan, and Germany), the number of elderly drivers is projected to sharply increase the rate of numerous challenges to public safety. Driving requires the integration of high-level cognition, vision, and motor function.2 Conversely, many physical and cognitive changes affect driving among the elderly, such as slower reaction time, hearing and vision problems, decreased ability to focus, and medical problems, including age-associated cognitive decline and the use of drugs affecting cognitive performance.3 Thus, although Klauer et al. note particular risks of distracted driving among young, inexperienced drivers, elderly drivers over the age of 75 (who were not included in the study) may be another group at particular risk, increasing the risk of morbidity and mortality of their passengers and other people on the road.4 Virginia Boccardi, M.D. Giuseppe Paolisso, M.D., Ph.D.
are a major concern, we often ignore a much more common risk factor: the use of cell phones while driving. The article by Klauer et al. and the accompanying Perspective article by Jones1 point out both the risks and the role of the physician. Since the behavior of physicians may influence patients, we should take a lead in this area. It may be difficult to modify physician behavior, since doctors are already being distracted with the use of smartphones during patient care, and there is the rationalization that we must use our free time in the car to return calls from patients. However, I propose that physicians should not speak to patients while they (or we) are using a cell phone while driving. If we call patients and they are driving, we should state that we will be happy to speak with them at a time when they are not distracted. Jonathan M. Silver, M.D. New York University School of Medicine New York, NY
[email protected] No potential conflict of interest relevant to this letter was reported. 1. Jones DS. Doctors and the dangers of driving. N Engl J Med
2014;370:8-11.
DOI: 10.1056/NEJMc1401241
The authors reply: Mick raises a concern that the rates of crashes and near-crashes in our study appear to be higher than those in published statistics. Crash databases typically include only severe crashes that are generated by police reports. In naturalistic driving studies (NDS), the conSecond University of Naples Naples, Italy tinuous, high-resolution data allow for the [email protected] tion of serious collisions, minor crashes, and nearNo potential conflict of interest relevant to this letter was recrashes, providing a comprehensive measure of ported. risk.1 Thus, the crash rate of the study population 1. Preusser DF, Williams AF, Ferguson SA, Ulmer RG, Weinstein HB. Fatal crash risk for older drivers at intersections. Accid is not higher than that in the general teenage Anal Prev 1998;30:151-9. driving population. However, our findings indi2. Sherman FT. Driving: the ultimate IADL. Geriatrics 2006; cate that participating teenagers were involved in 61:9-10. 3. Classen S, Horgas A, Awadzi K, Messinger-Rapport B, Shecht more “loss of control” events than was previousman O, Joo Y. Clinical predictors of older driver performance on a ly known. standardized road test. Traffic Inj Prev 2008;9:456-62. Regarding the comment by Young with re4. Braver ER, Trempel RE. Are older drivers actually at higher spect to age versus experience: we purposefully risk of involvement in collisions resulting in deaths or non-fatal injuries among their passengers and other road users? Inj Prev selected a target population of teenagers who 2004;10:27-32. had had their licenses for 3 weeks or less. Our DOI: 10.1056/NEJMc1401241 study was not designed to address the effects of age versus experience on distracted driving. The To the Editor: Physicians have an important results were analyzed and presented separately role in preventing disease, including traumatic for the novice drivers and the more experienced brain injury. Although concussions from sports drivers. Young also expresses concern about
n engl j med 370;16 nejm.org april 17, 2014
1565
The New England Journal of Medicine Downloaded from nejm.org at STOCKHOLMS UNIVERSTITETSBIBL on August 11, 2015. For personal use only. No other uses without permission. Copyright © 2014 Massachusetts Medical Society. All rights reserved.
The
n e w e ng l a n d j o u r na l
potential confounding in our study. Since this was an observational study, we acknowledge this possibility. However, we believe that random sampling of noncrash road segments, as we used for our control, minimizes the chance that such confounders substantially influenced the results. The continuous video collected by NDS allows for the precise separation of talking on a cell phone with visual–manual tasks associated with cell-phone use, which effectively averts any potential information bias associated with cell-phone use while driving. Young’s argument that previous research that was conducted on the basis of cell-phone records was limited to the risk associated with talking on but not with dialing a cell phone has been debated previously.2 In addition, others have reported that both the beginning and ending of cell-phone conversations, which are not reflected in billing records, require risky visual–manual tasks.3 Contributing factors leading to crashes typically unfold over time. Since the moment when a crash occurs is difficult to match precisely to time stamps in cell-phone records, the determination of a proximate cause is not possible on the basis of crash reports and cell-phone records. As noted by Boccardi and Paolisso, more research should be done on the effects of secondarytask involvement on the risk of crashes or nearcrashes for drivers of all ages. We also argue that more research on the effects of driver distraction should be conducted on specialty popu-
of
m e dic i n e
lations of drivers, including emergency responders (e.g., police officers and ambulance drivers), as well as physicians who are using their vehicle as a mobile office. As Silver notes, complex conversation is a distraction for drivers, but the effect of this type of conversation is not yet fully understood. Sheila G. Klauer, Ph.D. Feng Guo, Ph.D. Virginia Tech Transportation Institute Blacksburg, VA
[email protected]
Bruce G. Simons-Morton, Ed.D., M.P.H. Eunice Kennedy Shriver National Institute of Child Health and Human Development Bethesda, MD Since publication of their article, Dr. Klauer’s disclosure form has been updated to include grant support from the automotive industry and Dr. Guo’s disclosure form has been updated to include grant support from an accident-management company. The disclosure forms of Drs. Lee and Dingus, coauthors, have also been updated to include grant support from the automotive industry. No further potential conflict of interest relevant to this letter was reported. 1. Dingus TA, Klauer SG, Neale VL, et al. The 100-Car Natural-
istic Driving Study, Phase II — results of the 100-car field experiment. Washington, DC: National Highway Traffic Safety Administration, 2006 (http://www.distraction.gov/research/pdf-files/ the-100-car-naturalistic-driving-study.pdf). 2. Mittleman MA, Maclure M, Mostofsky E. Cell phone use and crash risk. Epidemiology 2012;23:647-50. 3. Fitch GM, Soccolich SA, Guo F, et al. The impact of handheld and hands-free cell phone use on driving performance and safety-critical event risk. Washington, DC: National Highway Traffic Safety Administration, 2013 (http://www.distraction.gov/ download/811757.pdf). DOI: 10.1056/NEJMc1401241
Sedation and Delirium in Intensive Care To the Editor: We agree with Reade and Finfer (Jan. 30 issue)1 that prevention of delirium in patients in the intensive care unit (ICU) is clearly preferable to treatment after the fact. Reduction or prevention of sleep deprivation may be an additional measure to reduce the risk of delirium in the ICU.2 Noise, light, and other factors may be associated with poor sleep quality. A reduction in these factors and promotion of positive sleep-hygiene behaviors are associated with a reduction in the incidence of delirium or coma.3 Because most sedatives degrade sleep architecture, their use may actually increase the risk of delirium, rather than reduce it.2 In addition to minimizing the use of sedative agents, other therapies warrant mention. Critically ill patients 1566
have a documented loss of a normal circadian rhythm associated with melatonin secretion.4 Exogenous melatonin may be an effective countermeasure to reduce abnormalities in sleep architecture, and preliminary data to this effect are encouraging.5 Data are lacking from studies to evaluate the effects of melatonin on sleep, delirium, and acute brain dysfunction in critically ill patients. We hope that future studies of delirium in the ICU include this therapy. Alexander H. Flannery, Pharm.D. Kevin W. Hatton, M.D. Barbara Phillips, M.D., M.S.P.H. University of Kentucky HealthCare Lexington, KY [email protected]
n engl j med 370;16 nejm.org april 17, 2014
The New England Journal of Medicine Downloaded from nejm.org at STOCKHOLMS UNIVERSTITETSBIBL on August 11, 2015. For personal use only. No other uses without permission. Copyright © 2014 Massachusetts Medical Society. All rights reserved.
