Comment
Advanced intensive care treatment prolongs the lives of those with conditions that would previously have been fatal, but can also produce a devastating condition known as chronic critical illness. A population-based prevalence of this complication in high-income countries is estimated to be around 35 cases per 100 000 people and growing.1 More than 100 000 chronically critically ill patients are alive in the USA at any point in time.2 The burdens of persistent critical illness are enormous. They affect patients, their families, health-care providers, and society as a whole. Chronic critical illness causes higher mortality than do most malignancies (20–49%),3,4 and survivors tend to have functional and cognitive disabilities and are often readmitted to hospital.2 Most survivors end up in skilled nursing facilities or long-term acute care hospitals, and only one in five patients is eventually discharged home.1 Furthermore, persistent critical illness is an expensive condition, with an annual cost estimated to be more than US$20 billion in the USA, straining the capacity of the health-care system as a whole.5 Finally, prolonging life at all costs is often not in accordance with most patients’ wishes. When asked, nine of ten seriously ill patients indicated that they would rather die than survive with severe impairments and disabilities.6 Defining chronic (ie, persistent) critical illness has been challenging. Kahn and colleagues1 used a consensusderived definition for chronic critical illness that included a minimum of 8 days of intensive care unit (ICU) treatment and at least one of six eligible conditions: tracheostomy, stroke, traumatic brain injury, sepsis, severe wounds, or prolonged mechanical ventilation. Previous definitions used a long duration of mechanical ventilation (longer than 21 days)7 or tracheostomy8 as inclusion criteria. In The Lancet Respiratory Medicine, Theodore Iwashyna and colleagues9 published a large retrospective multicentre observational study that included 1 028 235 critically ill patients admitted to the 182 ICUs in Australia and New Zealand during a 15 year period. Informed by a previous survey of ICU clinicians,10 the authors aimed to empirically establish the onset of the transition from acute to persistent critical illness. They defined the time of transition as the moment when outcome prediction is no longer related to initial severity of the illness, but to pre-ICU
patient characteristics. In this large cohort, diagnosis at admission progressively lost predictive ability and, after about 10 days in the ICU, no longer predicted outcomes better than did simple pre-ICU patient characteristics. This is consistent with the results of the previous survey.10 A syndrome of persistent critical illness is all too familiar to critical care clinicians, with the constellation of findings consisting of ventilator dependence, neuromuscular weakness, malnutrition, and psychocognitive dysfunction. However, investigators of previous epidemiological studies defined persistent critical illness on the basis of duration of ICU stay, mechanical ventilation, or specific procedures (tracheostomy), all of which are subject to variability in practice patterns and can greatly vary in different settings. The authors’ approach of defining the onset of persistent critical illness on the basis of its relationship with acute versus pre-existing outcome predictors is interesting and can be justified from a clinical and physiological standpoint as the achievement of new homeostasis after life-threatening physiological derangement in the setting of critical illness. Although the authors’ approach is intuitive and the definition is largely consistent with previously described outcome burdens, if this approach is truly advantageous compared with time-based definitions is unclear, particularly from the perspective of practicing clinicians. This study has brought to light the fact that a small number of cases (5%) with persistent critical illness consume a huge amount of ICU resources (33% of ICU bed-days). The results also substantiated high mortality (25%) and a lower chance of returning home after persistent critical illness (47%) than for those without persistent critical illness (78%). A somewhat higher proportion of return to home than that previously reported1 could be due to inclusion of patients with a better prognosis than those in previous studies, the availability of chronic nursing facilities, and different discharge practices in different settings. The study was done over a period of 15 years during which substantial improvements in the critical care practice have occurred,11 limiting the applicability of the overall findings at present. Moreover, the study could underestimate the true burden of chronic critical illness in other settings.
www.thelancet.com/respiratory Published online May 4, 2016 http://dx.doi.org/10.1016/S2213-2600(16)30066-2
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Chronic critical illness: unintended consequence of intensive care medicine
Lancet Respir Med 2016 Published Online May 4, 2016 http://dx.doi.org/10.1016/ S2213-2600(16)30066-2 See Online/Articles http://dx.doi.org/10.1016/ S2213-2600(16)30098-4
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Comment
Chronic critical illness is a challenging public health problem that demands an entire line of future investigations to identify potentially modifiable risk factors and develop effective treatment and prevention strategies. Many important questions need to be addressed. What can be done to improve clinical management and prevent complications? How can informed consent be provided during shared decision making in the setting of high-risk surgery or a complex medical condition? What is the role of palliative care? Considering the poor outcomes, high mortality, and negative effects on quality of life after a persistent critical illness, when is the right moment to stop with intensive care interventions? Being capable of distinguishing life worth living from unavoidable death is an everyday emotional and professional challenge for ICU clinicians, patients, and families. These important decisions profoundly affect patient’s lives, the destinies of their families, and society as a whole. Amra Sakusic, *Ognjen Gajic
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Department of Medicine, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN 55905, USA (AS, OG); Department of Medicine, Multidisciplinary Epidemiology and Translational Research in Intensive Care, Emergency and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA (OG); and Department of Internal Medicine and Department of Pulmonary Medicine, Tuzla University Medical Center, Tuzla, Bosnia and Herzegovina (AS)
[email protected]
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We declare no competing interests. Kahn JM, Le T, Angus DC, for the ProVent Study Group Investigators. The epidemiology of chronic critical illness in the United States. Crit Care Med 2015; 43: 282–87. Nelson JE, Cox CE, Hope AA, Carson SS. Chronic critical illness. Am J Respir Crit Care Med 2010; 182: 446–54. Nelson JE, Tandon N, Mercado AF, Camhi SL, Ely EW, Morrison RS. Brain dysfunction: another burden for the chronically critically ill. Arch Intern Med 2006; 166: 1993–99. Kahn JM, Carson SS, Angus DC, Linde-Zwirble WT, Iwashyna TJ. Development and validation of an algorithm for identifying prolonged mechanical ventilation in administrative data. Health Serv Outcomes Res Methodol 2009; 9: 117–32. Lamas D. Chronic critical illness. N Engl J Med 2014; 370: 175–77. Hopkins RO, Jackson JC. Long-term neurocognitive function after critical illness. Chest 2006; 130: 869–78. MacIntyre NR, Epstein SK, Carson S, Scheinhorn D, Christopher K, Muldoon S, for the National Association for Medical Direction of Respiratory Care. Management of patients requiring prolonged mechanical ventilation: report of a NAMDRC consensus conference. Chest 2005; 128: 3937–54. Cox CE, Carson SS, Holmes GM, Howard A, Carey TS. Increase in tracheostomy for prolonged mechanical ventilation in North Carolina, 1993–2002. Crit Care Med 2004; 32: 2219–26. Iwashyna TJ, Hodgson CL, Pilcher D, et al. Timing of onset and burden of persistent critical illness in Australia and New Zealand: a retrospective, population-based, observational study. Lancet Respir Med 2016; published online May 4. http://dx.doi.org/10.1016/S2213-2600(16)30098-4. IwashynaTJ, Hodgson CL, Pilcher D, Bailey M, Bellomo R. Persistent critical illness characterised by Australian and New Zealand ICU clinicians. Crit Care Resusc 2015; 17: 153–58. Kaukonen KM, Bailey M, Suzuki S, Pilcher D, Bellomo R. Mortality related to severe sepsis and septic shock among critically ill patients in Australia and New Zealand, 2000–2012. JAMA 2014; 311: 1308–16.
www.thelancet.com/respiratory Published online May 4, 2016 http://dx.doi.org/10.1016/S2213-2600(16)30066-2