WORCHESTER, MASS—Critically ill patients who require several weeks or more of mechanical ventilation make up only about 10% of the intensive care unit (ICU) population, yet they consume half of the ICU resources. In fact, some data suggest that only heart, liver, and lung transplant recipients consume more health care resources.[1]

To provide better care and reduce costs for patients on prolonged mechanical ventilation, Nicholas A. Smyrnios, MD, and colleagues devised and implemented a hospital-wide program that substantially sped these patients’ weaning from ventilation and shortened their hospital and ICU length of stay (LOS). This program saved several million dollars in a span of two years, the group recently reported.[2]

Interestingly, the program achieved these outcomes despite a steady rise in illness severity among the patients being weaned. Also important was the downward trend in hospital and ICU mortality for these patients, added Dr. Smyrnios, Director of the Medical ICU at the University of Massachusetts Medical Center in Worcester.

A COMPREHENSIVE PROCESS

To assess their hospital-wide program, Dr. Smyrnios and colleagues compared its performance in the first two years to the weaning outcomes observed the year before the program was implemented. Weaning practices during this baseline year were not standardized and included spontaneous breathing trials with a T-piece, as well as protocols that used continuous positive airway pressure (CPAP), synchronized intermittent mandatory ventilation, or pressure support ventilation.

For the new program, everyone involved agreed on once-daily spontaneous breathing trials as the hospital’s weaning technique of choice. The process would begin with an initial five-minute trial, the success of which would lead to a full CPAP trial that was not time-limited. All breathing trials were based on objective criteria for success or failure (see Table 1).

Table 1 To Wean or Not To Wean? Breathing Trial Criteria

Step 1: The Initial Five-Minute Weaning Trial Criteria for Success* • Respiratory rate of eight to 35 breaths/min • Spontaneous tidal volume greater than 2 mL/kg • Respiratory rate/tidal volume ratio less than 100 • Minute ventilation less than 15 L/min Step 2: Full CPAP Trial Criteria for Failure† • Diaphoresis • New atrial or ventricular arrhythmias • Apnea lasting more than 45 seconds • Inability to maintain an oxyhemoglobin saturation of at least 90% on a fraction of inspired oxygen of at least 0.6 • Systolic blood pressure declines greater than 15 mm Hg or rises exceeding 20 mm Hg • Breathlessness or fatigue exceeding 7/10 on the modified Borg Category Scale • Physician, nurse, or therapist assessment of weaning failure

CPAP = continuous positive airway pressure. * Patients must satisfy all of these criteria before a weaning attempt is made. † Patients who display any of these criteria at any time while on CPAP are returned to the ventilator at settings that provide full ventilatory support and allow maximum muscle rest. Patients who display none of these criteria remain on CPAP until they are extubated or, if appropriate, switched to a tracheotomy mask. Data extracted from Smyrnios et al. Crit Care Med. 2002.

However, the technique used was less important than the overall philosophy behind the weaning trials—that once the cause of respiratory failure has been stabilized and the patient’s condition has begun to improve, it is the delivery of appropriate medical care that is the primary determinant of weaning success.

“Rather than focus on a particular weaning technique, we now view weaning as a comprehensive process, a continuum,” remarked Dr. Smyrnios. “Hospitals contain so many impediments to weaning that it is almost impossible to know which technique is best. So, at this point, it is more important to streamline the weaning process and make sure everybody is following what we already know are best practices.”

To facilitate weaning, the program strongly stressed that physicians need to systematically address common medical barriers, such as cardiovascular dysfunction, fluid overload, and infection. “We also focus on identifying the most appropriate and cost-effective location of care,” related Dr. Smyrnios. “For example, when patients are no longer surgical cases, we move them from the surgical ICU to a medical ICU.”

Other methods of expediting patient flow through the system included integrating the activities of the acute and rehabilitation facilities and identifying and evaluating patients outside the medical ICU who could not be removed from the ventilator after three days of weaning attempts. Also, the entire program was directed and monitored by a pulmonary and critical care specialist and coordinated by two pulmonary nurses daily.

The program could not have succeeded without follow-up to ensure that protocols were being implemented, Dr. Smyrnios emphasized. “But rather than impose the program on everyone, we try to include them in it and get their genuine support,” he said.

RESULTS FOR THE FIRST TWO YEARS

The number of patients who required weaning rose from 220 at baseline to 247 during the first year of the new weaning program and to 267 during the second year. The patients, whose mean age was slightly higher than 60, were classified into diagnosis-related groups 475 (respiratory system diagnosis with mechanical ventilation) and/or 483 (tracheotomy except for mouth, laryngeal, or pharyngeal disorder). Their mean APACHE II scores were significantly higher in the first two years of the new program than at baseline (24.4 and 26.2 vs 22.2).

In the program’s first year, the mean hospital LOS dropped significantly to 31.6 days from 37.5 days at baseline; the mean ICU LOS fell from 30.5 to 25.9 days. A trend toward improvement occurred in the mean and median number of days on the ventilator, total cost per patient, and overall costs.

The researchers found even larger decreases in the mean hospital LOS (to 24.7 days) and ICU LOS (to 20.3 days) in the second year of the program. They also reported significant declines relative to baseline in the mean number of days on the ventilator (from 23.9 to 22.0) and total cost per patient (from $92,933 to $63,687). The overall cost savings that year surpassed $3.4 million, Dr. Smyrnios said.

Furthermore, in addition to a trend toward decreased hospital and ICU mortality, there were significant declines in the proportion of patients requiring tracheotomy (from 61% to 41%) or more than one course of mechanical ventilation (from 33% to 26%) during the two-year study. “Our goal now is to prove that we can sustain the program and its positive effects over a very long period,” Dr. Smyrnios acknowledged.

—Timothy Begany

References
1. Kurek CJ, Cohen IL, Lambrinos J, et al. Clinical and economic outcome of patients undergoing tracheotomy for prolonged mechanical ventilation in New York state during 1993: analysis of 6,353 cases under diagnosis-related group 483. Crit Care Med. 1997;25:983-988.
2. Smyrnios NA, Connolly A, Wilson MM, et al. Effects of a multifaceted, multidisciplinary, hospital-wide quality improvement program on weaning from mechanical ventilation. Crit Care Med. 2002;30:1224-1230.

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