Shift Work in Intensive Care

very promising area of research on the relationship between dietary factors and the severity of EIB. There is accumulating evidence that dietary modification has the potential to reduce the severity and incidence of asthma and EIB.2 It has repeatedly been shown that a low-sodium diet reduces postexercise airway narrowing2,3 and moderates airway inflammation3 in asthmatic subjects with EIB. It has also been shown that a 3-week fish oil diet, rich in omega-3 polyunsaturated fatty acids has a protective effect in suppressing EIB.4,5 In addition, antioxidant supplementation has also been shown to improve EIB to subclinical levels in significant numbers of individuals with EIB.2 The dietary factors mentioned above did not normalize postexercise pulmonary function in individuals with EIB. However, on average these dietary interventions did improve pulmonary function to below the clinical threshold of a 10% fall in postexercise FEV1, which is commonly used for diagnosis of EIB. This level of improvement is not unlike that attained with many pharmacologic treatments, which also do not necessarily normalize pulmonary function in EIB patients but do improve pulmonary function to subclinical levels. Thus, the potential for enhancing the quality of life for those individuals with EIB by dietary modification or supplementation is high. These findings point toward the prophylactic and acute therapeutic effects of selected dietary factors, which seem to be attainable by simple rearrangement of nutritional components, in patients with inflammatory diseases such as asthma and EIB.2 It is also possible that any beneficial effect of diet on asthma and EIB is mediated through the combined effect of a variety of nutrients, rather than through any single nutrient. Timothy D. Mickleborough, PhD Martin R. Lindley, PhD Indiana University Bloomington, IN The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal. org/misc/reprints.shtml). Correspondence to: Timothy D. Mickleborough, PhD, Indiana University, Bloomington, Department of Kinesiology, 1025 E 7th St, HPER 112, Bloomington, IN 47404; e-mail: [email protected] DOI: 10.1378/chest.130.2.623b

References 1 Parsons JP, Mastronarde JG. Exercise-induced bronchoconstriction in athletes. Chest 2005; 128:3966 –3974 2 Mickleborough TD, Gotshall RW. Dietary components with demonstrated effectiveness in decreasing the severity of exercise-induced asthma. Sports Med 2003; 33:671– 681 3 Mickleborough TD, Lindley MR, Ray S. Dietary salt, airway inflammation, and diffusion capacity in exercise-induced asthma. Med Sci Sports Exerc 2005; 37:904 –914 4 Mickleborough TD, Murray RL, Ionescu AA, et al. Fish oil supplementation reduces severity of exercise-induced bronchoconstriction in elite athletes. Am J Respir Crit Care Med 2003; 168:1181–1189 5 Mickleborough TD, Lindley MR, Ionescu AA, et al. Protective effect of fish oil supplementation on exercise-induced bronchoconstriction in asthma. Chest 2006; 129:39 – 49 To the Editor: We greatly appreciate the comments of Drs. Mickleborough and Lindley regarding our review of exercise-induced bronchoconstriction (EIB) in athletes. We agree that dietary modification is a promising new area of research in the management of EIB. 624

The studies cited by Drs. Mickleborough and Lindley highlight the need for further randomized clinical trials to determine the role of dietary modifications in the clinical management of EIB. Jonathan P. Parsons, MD John G. Mastronarde, MD, FCCP Columbus, OH The authors report that they have no conflict of interest related to this article. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal. org/misc/reprints.shtml). Correspondence to: Jonathan P. Parsons, MD, Ohio State University Medical Center, 473 W. 12th Ave, 201 HLRI, Columbus, OH 43210; e-mail: [email protected] DOI: 10.1378/chest.130.2.624

Shift Work in Intensive Care To the Editor: We read with great interest the study of Afessa et al (December 2005),1 which piloted a shift system for housestaff in a medical ICU. Although this represents a novel pattern of working among doctors in US training programs, this has become the accepted standard in the United Kingdom. The authors concluded that their study was insufficiently powered to detect significant differences in mortality, length of stay, or educational outcomes, and that a larger multicenter study may be required to address these issues.2 However, a possible confounding factor in this study was that the length and pattern of shifts may not have been optimal for reducing fatigue. While reduction to a 14-h shift represents a significant decrease both in the length of the duty period and the number of hours worked per week over the nonpilot period, in the United Kingdom this would, by current standards, be regarded as excessive. Although a decade or so ago the 100-h week was commonplace, national and European working-time legislation now limits doctors to working no ⬎ 56 h a week, with defined rest periods between shifts and days off between consecutive shifts. The optimal shift pattern for medical housestaff may be informed by data from the aviation industry, where safety is of paramount concern. Aviation accidents have a huge impact not only in financial cost but also in adverse public perception. This has focused the attention of aviation authorities on working patterns, fatigue, and error. The shift patterns of aircrew now consider circadian rhythms, quantity of sleep, and periods of wakefulness prior to duty periods in addition to length of shift.3 As a consequence, nighttime shifts are shorter than those during the day, and the number of consecutive night duty periods are restricted, with specific rest requirements before and after the shift in order to reduce the accumulated sleep deficit.4 In the study by Afessa et al,1 the shift pattern, and in particular working four consecutive 14-h night shifts, may abrogate the potential benefits of a shift system on patient outcome. Another possible reason why there was no demonstrable improvement in mortality or length of stay may have been the population of staff chosen for the implementation of a shift system. It seems more probable that the work patterns of senior doctors would be expected to have greater influence on patient outcomes than those of trainees. It is well-recognized that staffing ICUs with intensivists reduces morbidity, mortality, and costs.5–7 Unfortunately, in the United States a shortage of intensivists precludes the widespread adoption of this model of care.8 One solution, which increases senior input, is the development of telemedicine7; but this is unlikely to ever be the equivalent of the “hands-on” presence of an intensivist at the patient’s bedside. In Correspondence

the United Kingdom, intensivist staffing of the ICU is the norm, although these doctors operate an on-call system out of hours rather than being a permanent resident in the ICU. Since September 2004, intensivists here in Cardiff have abandoned the traditional on-call system in favor of providing a continuous resident service by working shifts.9 We believe that this change is more likely to benefit patients than altering the work patterns of our trainees, and as such is truly “a shift for the better.”2 Matt Wise, DPhil Paul Frost, FJFICM University Hospital of Wales Cardiff, UK The authors have no conflict of interests. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal. org/misc/reprints.shtml). Correspondence to: Matt Wise, DPhil, University Hospital of Wales, Cardiff, UK CF14 4XW; e-mail: [email protected] DOI: 10.1378/chest.130.2.624a

References 1 Afessa B, Kennedy CC, Klarich KW, et al. Introduction of a 14-hour workshift model for housestaff in the medical ICU. Chest 2005; 128:3910 –3915 2 Lilly CM, Landrigan CP. A shift for the better. Chest 2005; 128:3787–3788 3 Caldwell JA. Fatigue in aviation. Travel Med Infect Dis 2005; 3:85–96 4 Nicholson AN. EWTD: lessons from the air; college commentary 2005 [letter]. J R Coll Physicians Lond 2005; September/October: 39 5 Blunt MC, Burchett KR. Out-of-hours consultant cover and case-mix-adjusted mortality in intensive care. Lancet 2000; 356:735–736 6 Pronovost PJ, Angus DC, Dorman T, et al. Physician staffing patterns and clinical outcomes in critically ill patients: a systematic review. JAMA 2002; 288:2151–2162 7 Breslow MJ, Rosenfeld BA, Doerfler M, et al. Effect of a multiple-site intensive care unit telemedicine program on clinical and economic outcomes: an alternative paradigm for intensivist staffing. Crit Care Med 2004; 32:31–38 8 Pronovost PJ, Waters H, Dorman T. Impact of critical care physician workforce for intensive care unit physician staffing. Curr Opin Crit Care 2001; 7:456 – 459 9 Frost P, Wise M. Resident consultants in large intensive care units? Crit Care Resusc 2006; 8:50 –51 To the Editor We thank Drs. Wise and Frost for their letter about our article (December 2005).1 We agree that the suboptimal length and pattern of the shifts may have played confounding roles in our study. There are large differences in physicians’ working hours between Europe and the United States. The European Working Hour Directive limits physicians in training to work a maximum of 58 h/wk.2 In the United States, the Accreditation Council for Graduate Medical Education limits the working hours of residents and fellows to 80 h/wk.3 Compared to the traditional work hours in many teaching institutions in this country, our shift model represented a step forward. There are powerful drivers of change in organization and delivery of critical care in this country. Concerns for patient safety and the efficient utilization of limited resources are fueling a debate on critical care training requirements, accreditation, optimal staffing models, and sustainable work hours.4,5 Prolonged working hours compromise both patient safety and housestaff education.6,7 Drs. Wise and Frost also highlight the importance of 24-h intensivist staffing in order to improve patient outcomes. www.chestjournal.org

Although such staffing is unlikely to be universally implemented because of the shortage of critical care providers,8 their comment is well supported by several publications.9 Indeed, we know that consultant presence at the bedside increased as a byproduct of our resident shift work trial. However, as already acknowledged, our study was likely underpowered to demonstrate beneficial effects on patient outcomes. In recognition of the importance of intensivist presence at the bedside, we have recently implemented an in-house shift model for consultants and hope to describe the impact of this new staffing model on patient outcome as well as housestaff education in the future. Bekele Afessa, MD, FCCP Joseph C. Kolars, MD Rolf D. Hubmayr, MD, FCCP Rochester, MN The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be disclosed in this article. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal. org/misc/reprints.shtml). Correspondence: Bekele Afessa, MD, Division of Pulmonary and Critical Care Medicine, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905; e-mail: afessa.bekele@ mayo.edu. DOI: 10.1378/chest.130.2.625

References 1 Afessa B, Kennedy CC, Klarich KW, et al. Introduction of a 14-hour work shift model for housestaff in the medical ICU. Chest 2005; 128:3910 –3915 2 Pickersgill T. The European working time directive for doctors in training [editorial]. BMJ 2001; 323:1266 3 Accreditation Council for Graduate Medical Education. Report of ACGME work group on resident duty hours. June 11, 2002. Available at: www.acgme.org. Accessed July 20, 2006 4 Institute of Medicine. Crossing the quality chasm: a new health system for the 21st century. Washington, DC: National Academies Press Publications, 2004 5 Institute of Medicine. To err is human: building a safer health system. Washington, DC: National Academies Press Publications, 2000 6 Landrigan CP, Rothschild JM, Cronin JW, et al. Effect of reducing interns’ work hours on serious medical errors in intensive care units. N Engl J Med 2004; 351:1838 –1848 7 Lockley SW, Cronin JW, Evans EE, et al. Effect of reducing interns’ weekly work hours on sleep and attention failures. N Engl J Med 2004; 351:1829 –1837 8 Ewart GW, Marcus L, Gaba MM, et al. The critical care medicine crisis: a call for federal action; a white paper from the critical care professional societies. Chest 2004; 125:1518 – 1521 9 Pronovost PJ, Angus DC, Dorman T, et al. Physician staffing patterns and clinical outcomes in critically ill patients: a systematic review. JAMA 2002; 288:2151–2162

Work Shift Model for Housestaff in the Medical ICU To the Editor: We read with interest the article by Afessa et al (December 2005)1 describing the institution of a 14-h work shift for housestaff in the medical ICU (MICU). Another study2 found a reduction in the rate of serious medical errors when interns worked shorter MICU shifts. In the article by Afessa et al1 no CHEST / 130 / 2 / AUGUST, 2006

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