Feasibility of Early Mobilization Therapy in Mechanically Ventilated Patients

By Richard J. Wall, MD, MPH, Pulmonary Critical Care & Sleep Disorders Medicine, Southlake Clinic, Valley Medical Center, Renton, WA, is Associate Editor for Critical Care Alert.

Dr. Wall reports no financial relationship to this field of study.

Synopsis: This study provides a detailed description of the successful mobilization protocol, including barriers and complications, used in a recently published randomized trial.

Source: Pohlman MC, et al. Feasibility of physical and occupational therapy beginning from initiation of mechanical ventilation. Crit Care Med 2010;38:2089-2094.

Intensive care unit (ICU) survivors experience various morbidities that can limit long-term recovery. One of the most common problems, neuromuscular weakness, has been linked to substantial and lasting decrements in quality of life. In recent years, researchers have started exploring the utility of "early mobilization" (i.e., physical therapy while still in the ICU) to counteract this problem.

In a 2009 landmark study, early mobilization of mechanically ventilated patients led to improved functional independence, more ventilator-free days, and reduced ICU delirium.1 Patients were randomized either to the intervention of early physical/occupational therapy (PT/OT) or to usual care.

The results were impressive. A return to independent functional status by hospital discharge was seen in 59% of the intervention arm vs 35% of controls (P = 0.02). Patients in the intervention group also had shorter median duration of delirium (2 days vs 4 days; P = 0.02), and more ventilator-free days (24 vs 21 days; P = 0.05).

Although the authors described complication rates as low, lingering concerns remained for many of us who were trying to translate these findings into practice in our own ICUs.

In the current study, the authors offer a more detailed glimpse at what actually occurred in the intervention arm (n = 49 intubated patients). First, patients were screened for contraindications to initiating PT/OT (see Table 1, below). A protocol ensured that patients underwent daily sedative interruption unless neuromuscular blocking agents were being administered. To be considered "wakeful" a patient was required to follow at least three of four commands: open eyes to voice, track with eyes, squeeze hand on request, protrude tongue on command. On meeting wakefulness criteria, therapy was initiated. All medical devices were assessed and properly positioned before the session. The article describes the preparatory steps and various exercises employed in detail. Patients were reassessed each day.

Table 1. Contraindications to initiating PT/OT

  • Mean arterial pressure < 65 mm Hg
  • Heart rate < 40 or > 130 beats/min
  • Respiratory rate < 5 or > 40 breaths/min
  • Pulse oximetry < 88%
  • Evidence of elevated intracranial pressure
  • Active gastrointestinal bleeding
  • Active myocardial ischemia
  • Actively undergoing procedure
  • Agitation requiring increased sedatives in past 30 min
  • Insecure airway device

Overall, early PT/OT occurred at a median of 1.5 days after intubation. On average, therapy sessions lasted 26 minutes. Sedative infusions were stopped before therapy in 83% of patients. The majority of intubated patients were able to perform extremity exercises (85%), actively move in bed (76%), sit at the edge of bed (69%), simulate eating (67%), and groom themselves (64%). A substantial number of sessions saw patients move from bed to chair (33%) or stand (33%). Ambulation occurred in 15% of sessions (median, 15 feet).

"Potential barriers" were identified in 58% of sessions. For example, 35% of sessions had FiO2 of ≥ 0.6, a single vasopressor running in 17%, and two vasopressors running in 14%. Central venous catheters were present in 75%, arterial lines in 47%, dialysis catheters in 18%, and 37% of patients were obese (body mass index > 30 kg/m2). Delirium was seen in 53% of patients. Continuous renal replacement occurred during 9% of sessions. Among intubated patients, therapy was withheld in 26 of 270 eligible sessions. The most common reasons were ventilator dysynchrony (n = 20), blood pressure drop (n = 4), and active gastrointestinal blood loss (n = 2).

Despite a high number of potential barriers, adverse events led to discontinuation of therapy in only 16% of sessions (see Table 2, below). These included desaturation (6%), heart rate increase (4%), ventilator dysynchrony (4%), agitation/discomfort (2%), and device displacement (0.8%). Four devices were displaced without harm to patient (arterial line, rectal tube, nasogastric tube, and transient disconnection of ventilator circuit). Agitation after sedative interruption, requiring stopping therapy and resedation, occurred in < 10% sessions.

Table 2. Adverse events: Contraindications to continuing PT/OT

  • Mean arterial pressure < 65 mm Hg
  • Heart rate < 40 or > 130 beats/min
  • Respiratory rate < 5 or > 40 breaths/min
  • Pulse oximetry < 88%
  • Marked ventilator dysynchrony
  • Patient distress, combativeness
  • New arrhythmia
  • Concern for myocardial ischemia
  • Concern for airway device integrity
  • Fall to knees
  • Endotracheal tube removal

Commentary

Not surprisingly, a majority of critically ill patients have perceived "barriers" to early mobilization. According to the results of this study, however, adverse events resulting from those barriers are not a big problem. In this study, no patient was extubated, no central venous catheter was lost, and no serious arrhythmias ensued.

Nonetheless, perceived barriers are relevant because they can ultimately determine whether clinicians are willing to adopt protocols and follow through on actions. When an organization implements an early mobilization protocol, they would be wise to periodically audit the process, ensure goals are being met, survey staff, and feed those data back to frontline clinicians.

In my opinion, the real obstacle to early mobilization isn't lines, tubes, and drains. Rather, it's the rampant oversedation and delirium seen in mechanically ventilated patients. It makes little sense for an ICU to implement an early mobilization protocol if they don't have a working "sedation vacation" protocol in place. If a patient is unresponsive and unable to follow commands, PT/OT sessions will merely consist of passive range-of-motion exercises.

To be successful, an early mobilization protocol requires continuous interdisciplinary coordination between nurses, physicians, clinical pharmacists, respiratory therapy, and PT/OT. An early mobilization protocol is not a simple plug-play-and-walk-away add-on for the ICU.

Reference

  1. Schweickert WD, et al. Early physical and occupational therapy in mechanically ventilated, critically ill patients: A randomised controlled trial. Lancet 2009;373:1874-1882.