The publication of the June 2012 issue of the journal Respiratory Care followed a national symposium dedicated to the “chronically critically ill patient,” the patient with ongoing costly medical interventions, risk for medical complications and death, and the need for extensive post-acute care services.  One article and subsequent discussion was devoted to the topic of liberating patients on prolonged mechanical ventilation, or PMV patients, from their need for this ongoing treatment. PMV is defined, in this article, as mechanical ventilation needed for at least 21 days.

We know there are barriers to weaning patients from PMV, but it can be argued that we haven’t formally studied them enough to know how to overcome them. The barriers may include age, identifying windows of opportunity for weaning, a concurrent condition known as critical illness neuromyopathy (CINM) and cardiac issues.

Can we do a better job of weaning patients from prolonged mechanical ventilation?

That there would be a connection between age and weaning from PMV may seem obvious, but our understanding of this connection is somewhat limited and warrants further study. We know from animal studies that aging can affect diaphragm function, which can, in turn, lead to failure to wean from PMV.

Cardiac conditions such as myocardial ischemia, or reduced blood flow and oxygen to the heart, and arrhythmias, or abnormal heartbeat rhythms, can affect the weaning process as well, and these can be followed closely with a diagnostic tool called spontaneous breathing trials or SBTs. If we can better diagnose cardiac origins of weaning failure, it may be more possible to address these issues, optimize treatment and improve a patient’s cardiac status for weaning.

Better preventive and diagnostic strategies for CINM, which is very common in ICU settings and affects the function of muscles and nerves, may optimize weaning from PMV by more effectively addressing the weakness of respiratory muscles seen in CINM.

Successful weaning rates in PMV range tremendously, anywhere from 42 to 83 percent, depending on patient selection, site of care and other factors. Weaning protocols have helped to standardize the process but the further identification of subsets of patients may allow us to better individualize treatment and weaning strategies.  Selecting the right tracheostomy tube and correctly placing it, and selecting the best ventilator mode, are also essential to preparing patients for eventual successful weaning and should always be kept in mind.

Some advances in the treatment of certain subsets of patients may serve as success models for use in addressing other conditions that may affect weaning from PMV. For instance, a treatment known as diaphragm pacing, in which the diaphragm is stimulated with electrical impulses, has been used in some cases to help wean patients with spinal cord injury from PMV.

Finally we must remember that in certain settings and certain patients we may experience a pressure to persist in weaning attempts; abandoning the hope of weaning can be seen as a failure by patients and families. Continual reassessment of goals, wishes and progress by the patient, family and care team is important. Recovery and weaning expectations may need better management earlier, by better communication between caregivers, patients and families.

By: Sean R. Muldoon, M.D., M.P.H., F.C.C.P.
Senior Vice President and Chief Medical Officer
Kindred Healthcare Hospital Division

References:
Donahoe MP. Current venues of care and related costs for the chronically critically ill. Respiratory Care.<http://www.ncbi.nlm.nih.gov/pubmed?term=current%20venues%20of%20care%20and%20related%20costs%20for%20the%20chronically#> 2012 Jun;57(6):889-97; discussion 898-899.