Key Point

Whole-body rehabilitation can help speed weaning time in patients who are receiving chronic mechanical ventilation.

PHILADELPHIA—Patients receiving chronic mechanical ventilation are inarguably weak and deconditioned. However, the extent of this deconditioning is largely unexplored. Likewise, data regarding the effects of rehabilitation after chronic ventilation are scarce. Currently, no guidelines exist for rehabilitation of chronically ventilated patients, despite the high mortality rate and high costs of care for this group.

Researchers from Temple University School of Medicine in Philadelphia undertook an analysis of whole-body weakness in chronically ventilated patients and evaluated the impact of aggressive whole-body and respiratory muscle rehabilitation.¹

"Many of the patients in our whole-body rehabilitation program have long-term respiratory failure," said Ubaldo J. Martin, MD, Assistant Professor of Medicine and Director of Pulmonary Function and Rehabilitation at Temple University. "Many have COPD, but there are also patients with idiopathic pulmonary fibrosis, pulmonary arterial hypertension, neuromuscular disease, or obstructive sleep apnea."

The study included 49 consecutive patients who were admitted to the study center’s chronic ventilator-dependent rehabilitation unit (VRU) from surgical, medical, and cardiac ICUs. All patients had been mechanically ventilated for at least 14 consecutive days and underwent two failed attempts at weaning. A detailed history was taken and complete physical examination was performed for all patients. In addition, medical charts were reviewed to determine whether patients had been exposed to corticosteroids or neuromuscular-blocking agents during their ICU stay.

Rehabilitation was performed five days a week in a gym within the VRU. Therapy sessions lasted for 30 to 60 minutes. Once patients were able to breathe spontaneously for more than four hours, therapy could be given at the same time as spontaneous breathing trials. In those unable to breathe spontaneously, physical therapy was given while the patient used a portable ventilator. Oxygen saturation was maintained at 94% or higher during therapy. Patients with airway obstruction were given nebulized albuterol 30 minutes before their rehabilitation session. Patients progressed from one to two sessions per day as tolerated.

Initially, rehabilitation focused on improving trunk control and body posture. As trunk control improved, lower extremity ergometry, standing, and walking were added. Patients were successfully weaned once they tolerated 48 consecutive hours of unassisted breathing.

IMPROVEMENT SEEN IN ALL PATIENTS

The primary causes for respiratory failure were pneumonia in 15 patients, heart failure in nine, ARDS in eight, sepsis in eight, acute or chronic renal failure in three, and diaphragmatic dysfunction in two. Nine patients had a previous history of COPD. Patients were intubated for a mean of 18.1 days before tracheostomy placement and were transferred to the VRU a mean of seven days afterwards. The mean time to weaning measured from VRU admission was 16 days. Fifteen of the 49 patients were weaned in seven or fewer days.

Nine patients were exposed to neuromuscular-blocking agents and corticosteroids for more than five days. All patients were severely deconditioned at admission to the VRU and exhibited marked weakness of the upper and lower extremities.

At time of discharge from the VRU, all patients had a significant improvement in the combined motor strength score for upper and lower limbs. All patients were able to sit and stand at the end of the rehabilitation period. Notably, they had been bed bound at the time of VRU admission. Ambulation increased from 0 to a mean distance of 52 feet in the entire group, and 40 patients (81%) were able to walk at the time of discharge.

During the rehabilitation period, a significant correlation was seen between upper limb motor strength and time to wean. Conventional weaning variables at the time of VRU admission or on the day of weaning did not have a significant correlation with weaning success.

Stepwise regression analysis revealed that the only significant variables affecting time to wean were upper limb motor strength and exposure to neuromuscular-blocking agents and/or systemic corticosteroids.

WHAT IT TAKES TO SET UP A VRU

VRUs are not common in most hospitals, Dr. Martin noted. "For whole-body rehabilitation, you need a special area with space for enough patients, and a multidisciplinary approach. The VRU at Temple University has space for 20 patients. Pulmonary physicians, fellows, pharmacists, specialized nurses, and physical therapists are all involved," he explained. "Ideally, there should also be a gym in the area for physical training. In addition, respiratory therapists must be present because some patients have to do the exercises while on a ventilator. A psychologist and nutritionist provide additional support." He added that physical therapists can be easily trained to work with pulmonary rehabilitation patients.

Dr. Martin stressed that there is not enough research into this type of practice. "No one really knows the advantages or disadvantages of whole-body rehabilitation. At some point there has to be a set of guidelines, especially regarding which patients have the most rehabilitation potential. Conventional weaning parameters are not very accurate in these patients," he pointed out.

In the present study, the lack of difference between patients who weaned quickly and those who took longer suggests that whole-body rehabilitation results in similar positive outcomes regardless of body strength when rehabilitation began.

"The benefits of whole-body rehab very likely outweigh the costs," said Dr. Martin. "A lot of the patients are in the ICU. The very fact that they are being taken off the ventilator—even for a short while—is reducing health care costs."

—Gale Jurasek

Reference
1. Martin UJ, Hincapie L, Nimchuk M, et al. Impact of whole-body rehabilitation in patients receiving chronic mechanical ventilation. Crit Care Med. 2005;33:2259-2265.

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