Liberation from prolonged mechanical ventilation

After weaning from PMV, patients are usually far from ready to resume normal activities. A prolonged recovery period after catastrophic illness is the rule, with multidisciplinary rehabilitation and discharge planning efforts. Following such efforts, reports of success of restorative care are institutional and population specific. That all PMV patients are not "chronically critically ill" introduces selection factors that make comparisons between institutions even more difficult. Half of the authors' patients were able to go home in past years [14], although more recently, with patients admitted more debilitated and more ill, the percent returning home has gradually declined to the low 20% range. Bagley et al [11] report discharge to home in 31% of patients weaned. Gracey et al [6,133], treating younger, postsurgical patients, have reported the highest discharge to home rate, 57%; over 70% were eventually discharged to home after first being transferred to a rehabilitation unit. On the other hand, the few reports of survival 1 or more years after discharge are in the 50% range at best (Table 2). Carson and colleagues [9] report a 23% 1-year survival in 133 PMV patients. Their premorbid functional status and age analysis showed younger and more independent patients having a better mortality (56%), and older and more dependent patients having a 95% mortality at 1 year. Nasraway et al [25] report a 1-year mortality of 50.5% in 97 patients transferred from five ICUs to multiple ECFs. Most of these patients would probably meet criteria for PMV, with median time mechanically ventilated 33 days, and 71 ventilator dependent at the time of ICU discharge. A report from 25 Vencor Hospitals [134] not included in Table 2 because weaning outcome was not reported, examines mortality and cost in patients > 65 years of age primarily referred for failure to wean from mechanical ventilation (91% of the cohort of 1619 patients.) There was a 58% in-hospital mortality by day 102 (28 days in the acute care hospital before referral, 74 days in the LTAC afterward), and a 67% mortality in postdischarge follow-up to day 180. Results of functional status studies and quality-of-life (QQL) measures, some using validated instruments, are now being reported in small series of PMV patients. These will merit consideration as important as weaning outcome, disposition, and survival data, as they accumulate to round out the treatment results in this population. Using a proprietary instrument, Carson et al [9] found 42% of 1-year survivors, that is, 8% of study patients, functionally independent at 1 year after discharge. Nasraway [25], using a single-question QQL assessment, and a validated functionality measurement, found 11.5% of his original cohort at home, breathing independently, with a "fair or better" QOL and good physical functionality. In a preliminary report from Dr. Criner's VRU, objective physical improvement was demonstrated in rehabilitation after PMV, using a functional independence measure scale [89]. A full report from the same unit, using a Sickness Impact Profile score makes it clear that PMV had no independent adverse effect on QOL several years later [135]. The 46 patients (25 of whom, with mean age 59 years, responded to the follow-up questionnaire), followed for 24 months after the catastrophic episode, scored their QOL based on their underlying chronic diseases, if any. The older patients, status postsurgical illness, predominantly cardiac surgery, rated their QOL better than younger patients with acute or chronic diseases. Similar findings have been reported in a recent ICU study, reporting QOL after prolonged intensive care [136]. Those who work to liberate PMV patients from mechanical ventilation, a satisfying end in many ways, have demonstrated that this post-ICU critical care activity is usually safe, and successful, although only in observational studies. Will multicenter studies in PMV patients liberated from mechanical ventilation yield facility benchmark, weaning outcome, and survival data that warrant continuation of these activities on a cost-per-outcome basis? That remains to be seen. Assessing and interpreting QOL and functionality findings in these patients, many with underlying chronic diseases resulting in long convalescence and rehabilitation, is a particularly important challenge. The authors are participating in a multicenter study that will yield some of these data; no doubt others will also address these questions. In the mean time, "No one in our society is willing to put Grandma out on an iceberg because she's no longer contributing. Someone needs to take care of these people" [137].