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This report comes from Barlow Respiratory Hospital, a center in Southern California for weaning patients from prolonged mechanical ventilation in the post-ICU setting. Scheinhorn and colleagues devised a complex, respiratory therapist-implemented, patient-specific weaning protocol, tailored specifically to their patient population and practice approach. They then prospectively tracked patient outcomes, variance from the protocol, and compliance of both therapists and physicians during the protocol’s first 18 months, compared with data from the last 2 years prior to protocol implementation.
A total of 271 "unweanable" patients were transferred to Scheinhorn et al’s institution from ICUs of other hospitals during the protocol period, of whom 252 were considered potential weaning candidates; the historical control group comprised 238 patients who were also considered candidates for weaning. The same physicians treated both cohorts of patients; 46 respiratory therapists worked in the unit during the protocol period.
The duration of mechanical ventilation prior to transfer was similar in the 2 groups of patients. A total of 55% of the patients were successfully weaned during the protocol period, as compared to 58% during the preprotocol period; 18% and 11% were determined to be ventilator dependent, and 27% and 31% of the patients died, respectively (all differences not statistically significant). Protocol variances by physicians and respiratory therapists during 9135 total ventilator days during the protocol period comprised 324 and 136 ventilator days, respectively. The median time to wean was 17 days under the weaning protocol, as compared to 29 days prior to its implementation (P < .001). More rapid weaning (by an average of 16 days) for a greater proportion of patients who were ultimately weaned saved 1112 ventilator days in 70 patients per year, for a total of 570 ventilator days of hospitalization saved per year in 22 patients. (Scheinhorn DJ, et al. Chest. 2001;119:236-242.)
The special feature in the March 2001 issue on cost-effective respiratory management under managed care briefly summarized the mounting evidence that weaning from mechanical ventilation can be shortened and its associated costs reduced through the use of protocols carried out at the bedside by respiratory therapists and nurses.1 This topic has recently been reviewed more comprehensively.2 This study provides further evidence that weaning protocols can be effective, even in patients who have failed multiple weaning attempts and been transferred to a center of special expertise in caring for them.
Scheinhorn et al at Barlow Respiratory Hospital have unquestioned expertise in weaning the "unweanable" patient, having previously reported their experience with 1123 such patients.3 They are to be commended for the present study, in which they show that implementation of a therapist-driven weaning protocol can shorten the weaning process, even in a center of such recognized expertise. The key is not the know-ledge and experience of the physicians caring for the patients, but the hour-by-hour availability of decision-makers at the bedside. Respiratory therapists are not inherently better at ventilator weaning than doctors. They are, however, at the bedside more continuously, and can assess patients more frequently, moving them along more rapidly as improvement occurs—provided they are empowered to do so by a protocol authorized by the physician.
Although the physician may spend considerable time at the bedside when a patient is critically ill and unstable, once that patient improves and moves into the weaning phase of ventilatory support, the physician may be physically present only once or twice a day. If changes in ventilator settings can be made only at such times, it is hardly surprising that weaning a patient who is rapidly improving will take longer than if the physician (or someone else who could modify the ventilator settings) were present 2 or 3 times as frequently. Weaning protocols, developed with physician participation and tailored to the patient population and clinical practice of the individual institution, permit respiratory therapists and/or nurses to make the same assessments and ventilator changes as would be made if the physician were physically present.
It has been estimated that somewhere around 2 million patients undergo mechanical ventilation each year in the United States. A recent point-prevalence study of mechanical ventilation around the world found that, at any given moment, about half of all ventilated patients are considered by those caring for them to be in the weaning process.4 If the average patient spends 5 days on the ventilator, then weaning is in process for 5 million patient-days each year in this country (2 million patients ´ 5 days each ´ 50% spent weaning). In this context, the economic implications of even a slight reduction in average weaning time are staggering, something that is unlikely to be lost on those who pay for ICU care and increasingly regulate it.
Weaning protocols are here to stay. As the evidence of their safety and cost-effectiveness mounts, ICUs and respiratory care departments that have not yet implemented such protocols are likely to come under increasing scrutiny, not only from clinicians interested in providing the best possible patient care, but also from hospital administrators and third-party payers focused on minimizing the costs of providing that care.
1. Hess DR. Crit Care Alert. 2001;8:138-140.
2. Stoller JK. Respir Care. 2001;46:56-66.
3. Scheinhorn DJ, et al. Chest. 1997;111:1654-1659.
4. Esteban A, et al. Am J Respir Crit Care Med. 2000;161:1450-1458.