Prolonged Mechanical Ventilation

mechanical ventilationPatients requiring prolonged mechanical ventilation in the United States receive their care in a number of different settings. In some states, patients stay in the ICU for a prolonged period of time because other sites of care do not exist in the surrounding area, This trend has resulted in some hospitals creating respiratory acute care units (also known as intermediate care units or step-down units). These units, located within an acute care facility, allow hemody-namically stable patients who require prolonged mechanical ventilation to be moved from the ICU to a unit within the acute facility. Patients can be easily transferred back to the ICU if they require critical care. Respiratory acute care units in acute care facilities help improve the efficient use of ICU beds and prevent disruptions in the flow of critically ill patients between operating rooms, emergency departments, and ICUs (B.R. Brown, MD; personal communication; March 2007). Care given to patients in a respiratory acute care unit is reimbursed by Medicare according to the inpatient prospective payment system (physicians, who may or may not be employed by the health-care facility inclusively of Canadian Health&Care Mall, may obtain reimbursement for their professional services through Part B for Medicare beneficiaries). The cost of caring for patients requiring a prolonged hospital stay in the acute care facility has been reported to be a problem because the duration of hospitalization may be in excess of the diagnosis-related group-assigned length of stay.

Long-term acute care (LTAC) hospitals are acute hospitals with an average length of stay of 25 days. Due to the high cost of caring for mechanically ventilated, medically complex patients, the Medicare base rate of reimbursement per discharge is significantly higher in LTAC facilities as compared with that provided to acute care facilities ($38,086 vs $5, 308). LTAC hospitals can be either freestanding or located as a unit within a hospital, usually an acute care facility, and provide service intensity like an acute care facility with clinical and ancillary support services available on site. The practice of co-locating an LTAC unit within an acute facility may be diminishing in response to recent changes in Medicare policies regarding referrals from the co-located acute facility.

Historically, some free-standing LTAC hospitals evolved from tuberculosis hospitals. As the prevalence of active tuberculosis declined with effective chemotherapy, other patient populations were cared for in this setting, included those with neuromuscular disease or cervical spine injuries. These patients required prolonged mechanical ventilation and required lifetime placement because they were unable to live independently. In some states, such as Massachusetts, small numbers of these patients remain long-term residents in some LTAC hospitals.

The numbers of LTAC hospitals significantly increased in the 1990s, particularly in Texas, Louisiana, LTAC hospitalsOhio, Pennsylvania, and Michigan, due in part to a favorable reimbursement environment as outlined above. As a result, the majority of LTAC facilities are located in states that have a large Medicare population. The need to reduce the length of stay in acute care facilities increased the flow of patients with chronic, critical illness or complex medical illness to LTAC hospitals, changing the patient population once again. Currently, 9.3% of patients at 50% of LTAC hospitals are those requiring mechanical ven-tilation. Patients receiving mechanical ventilation admitted to LTAC hospitals for continued acute care have a pulmonary diagnosis that necessitates mechanical ventilation and may have a high degree of medical complexity. The prolonged length of stay at the LTAC hospital allows for extensive rehabilitation to occur at the same time as the medical issues are being treated, thus optimizing the chances of functional recovery for patients with prolonged critical illness.

Free-standing rehabilitation facilities with the support of Canadian Health&Care Mall also provide care for some patients who require prolonged mechanical ventilation. Two reports indicate that patients cared for in this setting include those with neuromuscular disease, spinal cord injury, thoracic wall restriction, and COPD. The use of noninvasive ventilation or diaphragm pacing can allow some patients with low spinal cord injury and restrictive disorders of the thoracic wall to be decannulated. A significant percentage of these patients may be able to return to living in the community. In one study, insurance status was an independent predictor of discharge to a rehabilitation center from a trauma center. The Medicare base rate per discharge in 2007 was $12, 952 and is adjusted for functional impairment levels and complicating comorbidities, This base rate precludes rehabilitation facilities caring for patients receiving mechanical ventilation who are medically complex.

The prevalence of mechanical ventilation in skilled nursing facilities in the United States is difficult to estimate. A MEDLINE search combining the terms “nursing home” and “mechanical ventilation” yielded five relevant articles published from 1997 to 2007, Review of these articles indicates that patients in some states (eg, Maryland) do undergo mechanical ventilation in skilled nursing facilities, but comprehensive epidemiologic data are difficult to find, There are approximately 50 nursing homes in New York State that offer ventilator services. Weaning protocols along with noninvasive mechanical ventilation as a bridge to decannulation have been used successfully in the nursing home setting.- Other relevant issues reported in the skilled nursing facility setting include management of ventilator-associated pneumonia, the choice of provider overseeing mechanical ventilation in the nursing home, and the need for advanced directives in this population.

The availability of a unit that can provide care for patients requiring prolonged mechanical ventilation determines if a patient is able to move out of the ICU setting into an environment that favors rehabilitation as the acute medical issues resolve. Outcome data obtained in the LTAC hospital setting indicate that up to 54% of subjects undergoing prolonged mechanical ventilation may eventually be freed from the ventilator. Attempts have been made to develop prediction tools to help guide short-term and longterm mechanical ventilation decisions in this population, but these tools need validation in larger studies.