There has been increasing recognition that mechanical ventilation is a part of the critical care continuum that goes beyond the confines of the intensive care unit (ICU).<sup>54 Scheinhorn D.J., Artinian B.A., Catlin J.L. Weaning from prolonged mechanical ventilation: The experience at a regional weaning center Chest 1994 ;  105 : 534  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> One third to one half of patients entering the ICU require mechanical ventilatory support. Most spend only two to four days receiving such support and do not require weaning. Their respiratory failure resolves quickly and mechanical ventilation is discontinued. Five to 15 percent of patients get stuck on the ventilator (i.e., require more than 7 days of mechanical ventilation).<sup>52 Rosen R.L., Bone R.C. Financial implications of ventilator care Crit Care Clinics 1990 ;  6 : 799

Cliccare qui per andare alla sezione Riferimenti, 67 Wagner D.P. Economics of prolonged mechanical ventilation Am Rev Respir Dis 1989 ;  140 (suppl) : 14

Cliccare qui per andare alla sezione Riferimenti</sup> That percentage may be increasing, as older and medically more complex patients are subjected to aggressive therapy for catastrophic illness. In a recent series including almost 6000 patients ventilated on the first day of ICU admission, 20.2% required mechanical ventilation for >7 days.<sup>58 Seneff M.G., Zimmerman J.E., Knaus W.A. , e al. Predicting the duration of mechanical ventilation: The importance of disease and patient characteristics Chest 1996 ;  110 : 469  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup>

Prolonged mechanical ventilation (PMV) is variously defined. At 21 days of mechanical ventilation for at least 6 hours per day, patients meet Health Care Financing Administration (HCFA) criteria for prolonged mechanical ventilation.<sup>9 Cohen I.L., Booth F.V.M. Cost containment and mechanical ventilation in the United States New Horizons 1994 ;  2 : 283

Cliccare qui per andare alla sezione Riferimenti</sup> HCFA's definition of PMV is a good one, as the pressure to transfer patients suffering PMV out of the ICU is, to a large extent, economic. In an oft-quoted article, Wagner<sup>67 Wagner D.P. Economics of prolonged mechanical ventilation Am Rev Respir Dis 1989 ;  140 (suppl) : 14

Cliccare qui per andare alla sezione Riferimenti</sup> showed that patients on mechanical ventilation for 21 days account for 37% of ICU costs, with the majority of the cost incurred after the seventh day. The cost of caring for all such patients nationally would then be approximately $25 billion per year.<sup>26 Halpern N.A., Bettes L., Greenstein R. Federal and nationwide intensive care units and healthcare costs: 1986–1992 Crit Care Med 1994 ;  22 : 2001  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 39 Levit K. , e al. National health expenditures, 1993 Health Care Financing Review 1994 ;  16 : 280

Cliccare qui per andare alla sezione Riferimenti</sup> For purposes of this review, PMV will be defined as mechanical ventilation for ≥21 days.