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Every year, over a million people in the U.S. suffer respiratory failure requiring mechanical ventilation. They experience enormous catabolic stress, extended periods of inactivity, and usually go without their usual caloric intake. It's no surprise that many are rendered profoundly debilitated by the experience. For many, this weakness and loss of muscle mass represents a second dangerous illness, putting them at risk for infections, falls, and poor resiliency to other illness.
To try to prevent these consequences of respiratory failure, "early mobilization" has become a leading trend of the past 10 years in critical care. Teams at true-believing medical centers have trained physical therapy and nursing to walk intubated patients down the hall with portable ventilators or ambu bags. Watered-down versions of the practice are seen widely at U.S. community hospitals, where PT works with ventilated patients in their beds.
But does intensive physical therapy in the ICU actually help people get stronger after mechanical ventilation?
Numerous randomized trials have tested intensive physical therapy against usual care in mechanically ventilated patients. Research results have been mixed, with many trials finding no benefit, and others showing generally small improvements in function. A recent trial in JAMA added to the conversation.
What They Did
Authors randomized 300 patients in the ICU at Wake Forest Baptist Medical Center in Winston-Salem, N.C., with acute hypoxic respiratory failure requiring mechanical ventilation between 2009-2014. Half the patients were randomized to receive intensive physical therapy, and half received usual care. The rehabilitation protocol included passive range of motion exercises, physical therapy, and progressive resistance exercises. These patients got 3 sessions a day for 7 days (including weekends), while usual care patients got PT on weekdays only when ordered by the primary team. Hospital length of stay was the primary endpoint. The study was funded by the NIH.
What They Found
More-intensive physical rehabilitation therapy in the ICU did not shorten hospital stays among patients with acute respiratory failure. Patients in both groups had a median 10 day hospital stay.
Early rehab in the ICU also did not reduce time spent on the ventilator (ventilator-free days) or time spent in the ICU (ICU-free hospital days).
There was also no difference between groups in hand-grip strength or handheld dynamometer strength at 6 months, nor in surveyed health status or mental health scores.
However, 24% of the patients dropped out; many could not participate because they were too sick or required too much sedation (patients were unconscious on 15% of their rehab days). There was no standard sedation protocol.
What It Means
Roughly one in four patients admitted to ICUs in the U.S. each year have acute respiratory failure requiring mechanical ventilation. Increasing attention is being paid to the prolonged physical and cognitive impairments that often result, called post-ICU syndrome. Can intensive rehabilitation in the ICU prevent post-ICU syndrome?
A smaller 2009 study by Schweickert et al (n=104) created much of the buzz around early mobilization by finding greater improvements in activities of daily living at hospital discharge in an early ICU rehabilitation group than the control group. However, they found no difference in hospital LOS either.
Most other randomized trials have not shown a benefit of early or intensive physical therapy at improving any meaningful clinical outcome, in patients with respiratory failure receiving mechanical ventilation:
- The RECOVER trial (n=240) gave rehab after the ICU stay. It didn't improve outcomes, but patients liked the extra attention.
- Moss et al found intensive physical therapy didn't improve physical function at 1, 3, or 6 months (n=120).
- In Australia and New Zealand: ditto (n=150, but didn't reach enrollment goal).
Authors put a positive spin on things, pointing our attention to the improved longer term functional outcomes, saying that they should be the primary focus of future trials:
In view of the SPPB, SF-36 PFS, and FPI data at 6 months, the [intensive rehab] group demonstrated potential improvement compared with the usual care group that was not evident at hospital discharge. It is not obvious what aspect of [rehab] may have accounted for the differences at 6 months; however, both the physical therapy and the progressive resistance training emphasized lower extremity function. The exposure in the hospital may have inclined the [rehab] group to have greater movement while in the outpatient setting.
Undoubtedly more study would be helpful, and it will be great if future studies show specific rehab regimens that can reduce the debilitation of post-ICU syndrome.
But intensive physical therapy takes considerable resources and entails some risk (falls, extubations, etc., until everyone gets used to the new practice). With the minimal or absent benefits being reported out thus far, it's not a surprise that hospitals have not staffed up en masse to join this latest trend in intensive care.
Read more: Standardized Rehabilitation and Hospital Length of Stay Among Patients With Acute Respiratory Failure. A Randomized Clinical Trial. JAMA. 2016;315(24):2694-2702