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Am Fam Physician. 2006;73(7):1277-1284

Improvements in intensive care treatment have increased the number of patients who survive acute respiratory failure, subsequently increasing the number of patients needing prolonged mechanical ventilation. These patients have specific needs that differ from those of patients needing acute intensive care. The National Association for Medical Direction of Respiratory Care (NAMDRC) convened to develop recommendations for the assessment and management of patients requiring prolonged mechanical ventilation. The NAMDRC consensus statement was published in the December 6, 2005, issue ofChest and is available online at The NAMDRC’s recommendations are summarized below.

Recommendation 1

Prolonged mechanical ventilation should be defined as at least 21 consecutive days of mechanical ventilation for six or more hours per day.

The literature includes varying definitions of what constitutes prolonged mechanical ventilation. The 21-day guideline is consistent with the length of ventilation commonly required by patients in long-term acute care settings. The guideline of six hours or more per day is consistent with the Centers for Medicare and Medicaid Services (CMS) requirement, although this may be too stringent. More studies are needed to better define prolonged mechanical ventilation.

Recommendation 2

Large prospective studies, especially those in the acute intensive care setting, should be conducted to better understand how to properly define prolonged mechanical ventilation.

The number of patients meeting the definition discussed in recommendation 1 is likely to increase; therefore, further research is needed to better define patients at high risk of death or significant long-term complications. Future studies should focus on patients in the acute intensive care unit (ICU) as well as those in the long-term acute care setting; consecutive patients should be identified and followed for one year.

Recommendation 3

In patients with slowly resolving respiratory insufficiency, successful weaning should be defined as complete liberation from mechanical ventilation for seven consecutive days.

Respiratory system recovery is slower and chronic comorbidities are more common in patients requiring prolonged mechanical ventilation compared with those in the acute ICU. Defining successful weaning from mechanical ventilation is further complicated by differences in patient population and health care institutions, discharge criteria, and revitalization for reasons other than failed weaning. However, defining a specific threshold for weaning success is important in assessing the effectiveness of weaning protocols, comparing health care institutions, and driving reimbursement rules.

Recommendation 4

Identification of factors associated with ventilator dependence should focus on those factors that are potentially reversible.

Numerous factors have been shown to contribute to ventilator dependence (Table 1). These factors include mechanical, iatrogenic, psychological, and process-of-care factors; systemic diseases; and long-term hospitalization complications. Consideration of these factors may help predict weaning success, although this approach has not been validated independently.

Long-term hospitalization complications
  • Deep venous thrombosis

  • Infection (e.g., pneumonia, sepsis)

  • Recurrent aspiration

  • Stress ulcers

  • Other medical complications developing during prolonged mechanical ventilation

Iatrogenic factors
  • Failure to recognize withdrawal potential

  • Inappropriate ventilator settings causing excessive loads or discomfort

  • Imposed work of breathing from tracheostomy tubes

  • Medical errors

Mechanical factors
  • Imbalance between increased work of breathing and respiratory muscle capacity

  • Increased work of breathing

  • Reduced respiratory capacity (e.g., critical illness polyneuropathy; myopathy from disuse or steroids; isolated phrenic nerve or diaphragmatic injury, possibly after surgery)

  • Upper airway obstruction (e.g., tracheal stenosis) preventing decannulation

Systemic diseases
  • Chronic comorbidities (e.g., malignancy, chronic obstructive pulmonary disease, immunosuppression)

  • Nonpulmonary organ failure

  • Overall severity of illness

  • Poor nutritional status

Process of care
  • Absence of weaning (and sedation) protocols

  • Inadequate nursing staff

  • Insufficient physician experience

Psychological factors
  • Anxiety

  • Delirium

  • Depression

  • Sedation

  • Sleep deprivation

Recommendation 5

When continuing the weaning process outside the ICU, the environment of care should be selected based on the patient’s needs and evaluated for effectiveness and safety.

Although mechanical ventilation usually is initiated in the ICU, patients should be transferred to an alternative care setting when appropriate. Patients can benefit significantly by receiving care that is more comprehensive and patient-focused than that offered in the ICU. Alternative settings include short- or long-term acute care, subacute care, skilled-nursing and rehabilitation facilities, and home care.

Recommendation 6

Transfer from ICU should be considered as soon as tracheostomy is considered.

A clinical assessment (e.g., no need for pressors or inotropes, acute illness has stabilized) can determine if a patient is ready for transfer to an alternative care setting. The appropriate timing of transfer consideration generally occurs when a tracheostomy is considered (as early as day 7). This allows one to two weeks to set up the transfer to the post-ICU setting.

Recommendation 7

Weaning strategies in the post-ICU setting should include nonphysician-implemented protocols and daily spontaneous breathing trials that progressively increase in duration as the level of ventilatory support decreases.

Because the weaning process usually is slower in the post-ICU setting, ICU protocols may not be applicable. Although the available evidence on post-ICU approaches to weaning is limited, starting daily spontaneous breathing trials after reducing the level of support to about one half of that required for full support is a common practice. Spontaneous breathing tests in the post-ICU setting differ from those in the ICU setting in two ways: (1) unsupported tracheostomy collars are used in the post-ICU setting rather than continuous positive airway pressure or low-level pressure support; and (2) post-ICU tests often exceed the 120-minute limit used in the ICU. Because post-ICU weaning focuses on rehabilitation rather than only ventilator dependence, nonphysician-implemented protocols (e.g., therapist-implemented) may be effective. Approaches will differ depending on available resources.

Recommendation 8

Weaning efforts should continue until the medical team and the patient or patient’s family agree they should cease; however, this group should have a frank and open discussion if weaning is deemed futile.

Relying on a strict time limit for continuing weaning efforts is inappropriate because decisions to cease efforts are based on multiple variables. When a joint decision is made to cease weaning efforts, focusing on palliative care, social services, and pastoral services can help facilitate discussions about continued care.

Recommendation 9

Palliative care services can benefit patients and their families when weaning efforts continue in the post-ICU setting and should be initiated if resources are available.

Palliative care focusing on pain relief, dyspnea, anxiety, and other symptoms associated with chronic critical illness is common in end-of-life care. However, many of these symptoms also are common in patients who require prolonged mechanical ventilation. Early consultation with a palliative care team can help ensure that these concerns are quickly identified and addressed.

Recommendation 10

Financial managers at facilities that offer prolonged mechanical ventilation should thoroughly understand Medicare’s Prospective Payment System (PPS), and the system should be modified to prevent financial incentives to discharge patients or delay treatment. Admissions should be based on clinical criteria, not on arbitrary quotas.

The main advantage of PPS is its simplicity (i.e., hospitals are paid similar amounts for similar patients). Hospitals can predict how much they will receive, patients can predict how much they will owe, and policy makers can easily change payments for all patients when cost of care is reduced. Although this system has disadvantages, the CMS appears committed to PPS; therefore, other proposed systems must work within PPS.

Recommendation 11

Leaders from various facilities that offer care for patients needing prolonged mechanical ventilation should regularly discuss options for improving PPS.

Facilities that offer care for patients needing prolonged mechanical ventilation rarely fit the PPS model, because they commonly are low-volume facilities, serve patients with highly variable diagnoses and comorbidities, and have limited discharge options. Therefore, addressing these differences can help ensure that PPS works properly in the post-ICU setting. Approaches that focus on incentives for these facilities, encourage patient transfer to the most effective facilities, and promote proper reimbursement may help ensure that PPS is effective.

Recommendation 12

Research funding should give high priority to studies that evaluate long-term outcomes in respect to patient selection, care processes, and care settings.

Stresses that are common in continued post-ICU weaning efforts (e.g., late mortality, ongoing morbidity, impaired mental health, decreased quality of life, emotional stress on family or caregivers) can increase the risk of late sequelae. Therefore, developing predictive models for intermediate outcomes (e.g., weaning success, hospital discharge) and long-term outcomes (e.g., survival, functional status, costs) through randomized multicenter trials is important. Subsequent follow-up studies on the implementation of proven therapies also are needed.

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