Mechanical ventilator weaning protocols driven by nonphysician health-care professionals: evidence-based clinical practice guidelines.

Health-care professionals (HCPs) can provide protocol-based care that has a measurable impact on critically ill patients beyond their liberation from mechanical ventilation (MV). Randomized controlled trials have demonstrated that protocols for liberating patients from MV driven by nonphysician HCPs can reduce the duration of MV. The structure and features of protocols should be adapted from published protocols to incorporate patient-specific needs, clinician preferences, and institutional resources. As a general approach, shortly after patients demonstrate that their condition has been stabilized on the ventilator, a spontaneous breathing trial (SBT) is safe to perform and is indicated. Ventilator management strategies for patients who fail a trial of spontaneous breathing include the following: (1) consideration of all remediable factors (such as electrolyte derangements, bronchospasm, malnutrition, patient positioning, and excess secretions) to enhance the prospects of successful liberation from MV; (2) use of a comfortable, safe, and well-monitored mode of MV (such as pressure support ventilation); and (3) repeating a trial of spontaneous breathing on the following day. For patients who pass the SBT, the decision to extubate must be guided by clinical judgment and objective data to minimize the risk of unnecessary reintubations and self-extubations. Protocols should not represent rigid rules but, rather, guides to patient care. Moreover, the protocols may evolve over time as clinical and institutional experience with them increases. Useful protocols aim to safely and efficiently liberate patients from MV, reducing unnecessary or harmful variations in approach.

Sleep histories are seldom documented on a general medical service.

BACKGROUND: Sleep disorders are common, but the frequency of sleep history documentation in hospitalized patients is unknown. METHODS: We reviewed 442 initial histories and physical examinations recorded by 122 house officers and 47 medical students in 208 consecutive general medicine ward patients. RESULTS: Any reference to sleep was recorded in only 18 patients (9%), including 12 of 141 (9%) with conditions associated with obstructive sleep apnea. Sleep histories were recorded more often in women (13% vs 4%) and less often than histories of cigarette smoking or alcohol use. Medical students recorded such histories more often than did house officers. Patients with sleep histories more often had pulse oximetry (78% vs 37%), pulmonary function testing (11% vs 1%), arterial blood gas analysis (67% vs 30%), or electrocardiograms (78% vs 49%). CONCLUSIONS: Sleep histories are documented infrequently in hospitalized patients. Patients with a recorded sleep history more often have tests that suggest increased concerns about cardiorespiratory risk and/or a different process of care.

Radiologic determination of intravascular volume status using portable, digital chest radiography: a prospective investigation in 100 patients.

OBJECTIVE: To answer the following questions: Can the digital chest roentgenogram (CXR) be used to differentiate patients' volume status? Do clinical data alter radiologists' accuracy in interpreting the digital CXR? DESIGN: Prospective cohort study. SETTING: Nine adult intensive care units of a tertiary care medical center. PATIENTS: One hundred thirty-five consecutive patients with pulmonary artery catheters, of whom 35 were excluded because of unacceptable pulmonary artery occlusion pressure (PAOP) tracings. METHODS: Each patient had a portable, anteroposterior, supine digital CXR. Clinicians evaluated volume status and then measured hemodynamic data within 1 hr of the CXR. Digital CXRs were independently interpreted on two separate occasions (with and without clinical information) by three experienced chest radiologists, and these interpretations were compared with hemodynamic data. RESULTS: Of the 100 patients, 39 had PAOP >18 mm Hg, whereas 61 had PAOP <18 mm Hg. Radiologists' accuracy in differentiating volume status increased with incorporation of clinical data (56% without vs. 65% with clinical data, p =.009). Using objective receiver operating characteristic-derived cutoffs of 70 mm for vascular pedicle width and 0.55 for cardiothoracic ratio, radiologists' accuracy in differentiating PAOP >18 mm Hg from PAOP <18 mm Hg was 70%. The intrareader and the inter-reader correlation coefficients were very high. The likelihood ratio of the CXR in determining volume status using the objective vascular pedicle width and cardiothoracic ratio measures was 3.1 (95% confidence interval, 1.9-6.0), significantly higher than subjective CXR interpretations with and without clinical data (p <.001). CONCLUSIONS: Differentiating intravascular volume status with portable, supine, digital CXRs may be improved by using objective cutoffs of vascular pedicle width >70 mm and cardiothoracic ratio >0.55 or by incorporating clinical data.

Flexible bronchoscopy in the elderly.

The established roles of flexible bronchoscopy in patients with diverse respiratory diseases, together with the demographic imperative posed by the aging of the population, make it important to understand factors relevant to this procedure in the elderly and to identify ways to optimize its performance. Relatively few investigations address specific influences of age on bronchoscopy but suggest that older patients age alone neither requires major modification of the approach nor introduces unacceptable hazards. The crucial relationships between bronchoscopy, the prevalence of specific respiratory diseases under consideration, and the impact of the procedure on patient management algorithms must be addressed in the future prospective investigations of the process of care in the elderly.

Predictors of successful extubation in neurosurgical patients.

A respiratory therapist-driven weaning protocol incorporating daily screens, spontaneous breathing trials (SBT), and prompts to caregivers has been associated with superior outcomes in mechanically ventilated medical patients. To determine the effectiveness of this approach in neurosurgical (NSY) patients, we conducted a randomized controlled trial involving 100 patients over a 14-mo period. All had daily screens of weaning parameters. If these were passed, a 2-h SBT was performed in the Intervention group. Study physicians communicated positive SBT results, and the decision to extubate was made by the primary NSY team. Patients in the Intervention (n = 49) and Control (n = 51) groups had similar demographic characteristics, illness severity, and neurologic injuries. Among all patients, 87 (45 in the Control and 42 in the Intervention group) passed at least one daily screen. Forty (82%) patients in the Intervention group passed SBT, but a median of 2 d passed before attempted extubation, primarily because of concerns about the patient's sensorium (84%). Of 167 successful SBT, 126 (75%) did not lead to attempted extubation on the same day. The median time of mechanical ventilation was 6 d in both study groups, and there were no differences in outcomes. Overall complications included death (36%), reintubation (16%), and pneumonia (9%). Tracheostomies were created in 29% of patients. Multivariate analysis showed that Glasgow Coma Scale (GCS) score (p < 0.0001) and partial pressure of arterial oxygen/fraction of inspired oxygen ratio (p < 0.0001) were associated with extubation success. The odds of successful extubation increased by 39% with each GCS score increment. A GCS score > or = 8 at extubation was associated with success in 75% of cases, versus 33% for a GCS score < 8 (p < 0.0001). Implementation of a weaning protocol based on traditional respiratory physiologic parameters had practical limitations in NSY patients, owing to concerns about neurologic impairment. Whether protocols combining respiratory parameters with neurologic measures lead to superior outcomes in this population requires further investigation.

Hemoptysis in patients with renal insufficiency : the role of flexible bronchoscopy.

STUDY OBJECTIVES: To assess the indications, yield, and therapeutic impact of flexible bronchoscopy (FB) in patients with hemoptysis and renal insufficiency. DESIGN: Retrospective cohort analysis. SETTING: Tertiary-care university hospital. PATIENTS: Thirty-four patients over a 7.5-year period who underwent FB to evaluate hemoptysis in the setting of renal insufficiency (ie, serum creatinine level, > 1.5 mg/dL). MEASUREMENTS AND RESULTS: The etiology of hemoptysis was undetermined in 41% of cases. Defined causes of bleeding included infections (29%), pulmonary renal syndromes (15%), airway injury (9%), and pulmonary embolism (6%). No specific bleeding site was identified, but FB lateralized hemorrhaging to one lung in 24% of patients. FB results influenced therapy in 29% of patients overall and in 8% of patients without respiratory tract infection. The hospital survival rate was 47% and did not differ based on the presence or absence (presence vs absence) of the following variables: a defined etiology for hemoptysis (45% vs 50%); lateralized bleeding (38% vs 50%); or management alterations prompted by other FB findings (50% vs 46%). Factors associated with survival included the onset of bleeding prior to hospital admission (80% vs 33%; p = 0.02), the absence of respiratory failure requiring mechanical ventilation at the time of FB (90% vs 29%; p = 0.002), and lack of prohemorrhagic factors (other than uremia) such as disseminated intravascular coagulation, recent treatment with warfarin, heparin, or antiplatelet agents (78% vs 33%; p = 0.05). During the 6 months following hospital discharge, hemoptysis recurred in 14% of patients, and 5 patients died, for an overall mortality rate of 62%. CONCLUSIONS: These data suggest that FB in hospitalized patients with hemoptysis and renal insufficiency, and without radiographic findings suggesting neoplastic disease, has a low yield and limited impact. Whether FB influences outcome in selected patients in this setting requires prospective investigation.

The usefulness of positron emission tomography in evaluating patients for pulmonary malignancies.

STUDY OBJECTIVE: Positron emission tomography (PET) can contribute to diagnosing and staging lung cancer, but it has not been determined whether this information influences patient care. DESIGN: We reviewed the effects of thoracic PET scan results during an 11-month period. For each patient, physicians ordering these scans reported how PET specifically altered management, and graded the ease of interpretation and overall usefulness of PET on a 5-point scale. In addition, to appraise general attitudes about PET, we surveyed 488 national American Thoracic Society (ATS) members and 44 physicians at our comprehensive cancer center. RESULTS: One hundred twenty-six questionnaires regarding patients were mailed to 37 ordering physicians, and 98 responses (78%) were returned, primarily by cardiothoracic surgeons (35%) and pulmonologists (47%). Respondents reported that PET provided new information in 83 patients (85%) and altered patient management in 64 cases (65%). Major effects on management included decisions regarding biopsy (n = 16), surgery (n = 16), and palliative treatment (n = 16). Chest clinicians found PET to be more helpful (4.4 vs 3.9, p = 0.007) and easier to interpret (4.2 vs 3.7, p = 0.025) than other specialists. Among 139 ATS members (28%) responding to the general survey, 51 members (39%) had access to PET. PET was more frequently available to university-based (49%) than community-based (27%) physicians (p = 0.016). The majority of physicians without current access to PET (69%) indicated that they would like to have it available. ATS members with access to PET reported that PET results generally affect decisions regarding biopsy or surgery most often, but found the procedure less helpful than physicians at our center (2.77 vs 3. 56, p = 0.003) and ordered it less often for lung cancer staging (60% vs 96%, p = 0.002). CONCLUSION: PET scanning is useful in the management of patients with suspected thoracic malignancies, but impressions about its roles vary, with PET regarded more highly where, as at our center, it is used more often. Whether PET alters patient outcomes requires investigation.

Managing life-threatening hemoptysis: has anything really changed?

STUDY OBJECTIVES: To delineate current chest clinicians' approaches to the management of patients with life-threatening hemoptysis. DESIGN: Survey during a computer-assisted interactive continuing medical education presentation. SETTING: The 1998 American College of Chest Physicians (ACCP) Annual Scientific Assembly. PARTICIPANTS: Chest clinicians attending the respiratory emergency symposium. RESULTS: Most clinicians (86%) had cared for patients with life-threatening hemoptysis, and 28% had cared for patients with fatal events during the previous year. Those clinicians favored management in the ICU setting (95%) with early endotracheal intubation (85%), and they tended to use a large-bore, single-lumen endotracheal tube (57%). The majority (64%) favored the early performance of diagnostic bronchoscopy during the first 24 h. Most clinicians (79%) used the flexible instrument, a higher frequency than respondents at a similar symposium on hemoptysis at the 1988 ACCP meeting (48%; p < 0.0001). Most current clinicians (77%) had experience with endobronchial measures to control bleeding, but few (14%) found them to be consistently worthwhile. Chest CT scanning was often helpful in diagnosis (55%). In their management of bleeding, half of these clinicians favored the use of interventional angiography, even in operable patients, which is a substantial change from 1988 when 23% had favored this approach (p < 0.0001). CONCLUSIONS: During the past decade, life-threatening hemoptysis has remained an important problem. Flexible bronchoscopy and interventional angiography have become increasingly established, more widely accepted approaches to patient care.

Bronchoscopy training: current fellows' experiences and some concerns for the future.

OBJECTIVES: To determine current pulmonary fellows' perspectives about their bronchoscopy training. DESIGN: Survey of 59 pulmonary fellows selected by training program directors to represent their institutions. SETTING: "Hands-on" symposium at the CHEST 1998 annual meeting, Toronto, Canada. RESULTS: Fellows reported a mean (+/- SD) of 2.4+/- 0.7 years of training, estimated they had performed 77.7+/-34 bronchoscopies per year, and had generally high estimates of their bronchoscopy proficiency and training. Proficiency estimates correlated with number of procedures cited (r = 0.43, p = 0.001) or level of fellowship training (r = 0.40, p = 0.002). Proficiency ratings (r = 0.63, p = 0.0001) and procedure numbers (r = 0.45, p-0. 0004) correlated with program quality ratings. Approaches to bronchoscopy instruction varied, and most often consisted of one-to-one instruction by faculty (92.5%), lecture-based instruction (74.6%), and case discussions (72.9%). Use of bronchoscopy lectures (p = 0.008) or videos (p = 0.057) were associated with higher self-estimates of proficiency, whereas use of lectures (p = 0.002), a bronchoscopy text (p = 0.009), and one-on-one instruction (p = 0.05) were associated with more highly ranked programs. Major components of training varied among programs. Although most fellows had received instruction encompassed in basic bronchoscopy, fewer had experience with bronchoscopic intubation (71.2%), transbronchial needle aspiration (72.9%), quantitative bacterial culture (64.4%), stent placement (27.1%), laser photocoagulation (25.4%), or cryotherapy (6.8%). Components of bronchoscopy experiences correlated with fellows' estimates of bronchoscopy proficiency and program quality. CONCLUSIONS: Approaches to bronchoscopy instruction and the components of bronchoscopy experiences vary considerably among institutions and are associated with pulmonary fellows' perceptions of bronchoscopy proficiency and training program quality. Definition of an optimum bronchoscopy curriculum remains necessary.

Massive left diaphragmatic separation and rupture due to coughing during an asthma exacerbation.

We report a case of herniation of abdominal contents into the left hemithorax in a patient hospitalized with an acute exacerbation of asthma accompanied by paroxysms of coughing. There was no history of trauma. We believe this is the first reported case of diaphragmatic rupture complicating an asthma exacerbation. We review clinical features, pathophysiology, diagnosis, and treatment of diaphragmatic rupture in its most common setting, trauma, and discuss its occasional "spontaneous" occurrence.

Increasing use of bronchoscopic needle aspiration to diagnose small cell lung cancer.

OBJECTIVE: To review pathology reports to determine whether a temporal change in diagnostic procedures that included bronchoscopic needle aspiration (BNA) in evaluation of small cell lung cancer (SCLC) had occurred. METHODS: A retrospective review of the computerized pathology database of the Wake Forest University Baptist Medical Center from 1990 to 1998 was performed. All pathology reports of patients newly diagnosed with SCLC were reviewed and abstracted. RESULTS: The number of patients newly diagnosed with SCLC during the 9-year study period totaled 277. Of these, 173 underwent bronchoscopy. From January 1990 to December 1991, 32% (8/25) of bronchoscopies done in patients with SCLC included BNA compared with 81% (120/148) (P < .001) from January 1992 to December 1998. In addition to the increased use of BNA in patients with SCLC undergoing bronchoscopy, the overall diagnostic yield for BNA in SCLC significantly increased over the 9-year study period from 50% (4/8) in 1990 and 1991 to 88% (106/120) thereafter (P = .001). Overall sensitivity of BNA during bronchoscopy was 86% for SCLC with only a small increase in sensitivity with use of all procedures (including BNA) to 91%. The use of forceps biopsy and bronchial brushings decreased over this period. CONCLUSION: With progressive experience with BNA, the frequency of its performance and its diagnostic yield in patients with SCLC increased markedly. The SCLC yield may be a worthwhile marker of BNA program development.

Education of physicians-in-training can decrease the risk for vascular catheter infection.

BACKGROUND: Procedure instruction for physicians-in-training is usually nonstandardized. The authors observed that during insertion of central venous catheters (CVCs), few physicians used full-size sterile drapes (an intervention proven to reduce the risk for CVC-related infection). OBJECTIVE: To improve standardization of infection control practices and techniques during invasive procedures. DESIGN: Nonrandomized pre-post observational trial. SETTING: Six intensive care units and one step-down unit at Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina. PARTICIPANTS: Third-year medical students and physicians completing their first postgraduate year. INTERVENTION: A 1-day course on infection control practices and procedures given in June 1996 and June 1997. MEASUREMENTS: Surveys assessing physician attitudes toward use of sterile techniques during insertion of CVCs were administered during the baseline year and just before, immediately after, and 6 months after the first course. Preintervention and postintervention use of full-size sterile drapes was measured, and surveillance for vascular catheter-related infection was performed. RESULTS: The perceived need for full-size sterile drapes was 22% in the year before the course and 73% 6 months after the course (P < 0.001). The perceived need for small sterile towels at the insertion site decreased reciprocally (P < 0.001). Documented use of full-size sterile drapes increased from 44% to 65% (P < 0.001). The rate of catheter-related infection decreased from 4.51 infections per 1000 patient-days before the first course to 2.92 infections per 1000 patient-days 18 months after the first course (average decrease, 3.23 infections per 1000 patient-days; P < 0.01). The estimated cost savings of this 28% decrease was at least $63000 and may have exceeded $800000. CONCLUSIONS: Standardization of infection control practices through a course is a cost-effective way to decrease related adverse outcomes. If these findings can be reproduced, this approach may serve as a model for physicians-in-training.

The distribution of costs of care in mechanically ventilated patients with chronic obstructive pulmonary disease.

OBJECTIVES: To delineate the costs of care of patients with Chronic Obstructive Pulmonary Disease (COPD) and respiratory failure and to compare them with those of other mechanically ventilated patients. DESIGN: A post hoc analysis of a prospective investigation. SETTING: Medical and coronary intensive care units (ICUs) of an 804-bed, university-based hospital. PATIENTS: A total of 300 mechanically ventilated patients, 44 with COPD and 256 others, were included. MEASUREMENTS AND MAIN RESULTS: Despite similar lengths of ICU stay (9 days) and mechanical ventilation (5.5 days COPD vs. 5 days other, p = .11), ICU respiratory care costs for patients with COPD were $2,422 ($1,157-$6,110) [median U.S. dollars (interquartile range)] vs. $1,580 ($738-$3,322) for the others (p = .01). Ventilator costs for COPD patients were $1,795 ($943-$5,782) vs. $1,574 ($613-$3,112) (p = .12). Total hospitalization respiratory care costs for COPD patients were higher, $4,064 ($2,422-$9,572) vs. $2,342 ($1,186-$4,591), (p = .0001), and 74.4% of the median difference in cost between COPD patients and others was accounted for by spontaneous nebulizers (p = .001), metered dose inhalers (p = .01), and pulse oximetry (p = .02). By using multiple linear regression analyses, we found that COPD remained associated with higher respiratory costs (p<.05). Respiratory Care was the third largest category of hospital costs after beds (27%) and pharmacy expenses (25%), and it comprised approximately 14% of total cost. Total hospital costs were large for both groups, but did not differ between COPD and the others [$24,217 ($16,211-$58,834) vs. $27,672 ($15,692-$53,766), respectively (p = .96)]. Linear regression analyses showed that only Acute Lung Injury score was significantly related to total ICU and hospital costs of care (p<.05). CONCLUSIONS: Costs of ICU and non-ICU respiratory care for patients with COPD are higher than costs of care for other mechanically ventilated patients. Although the increased cost of bronchodilators and oximetry in these patients may serve as target areas for reductions in respiratory care costs, it may also be true that these modalities of therapy and management are necessary and need to be used with even greater intensity to achieve better outcomes. The predominant contributions of bed and pharmacy costs in all of our patients with respiratory failure support research efforts addressing these aspects of care.

Bronchoscopic needle aspiration biopsy.

Bronchoscopic needle aspiration biopsy, which encompasses transbronchial needle aspiration, transtracheal needle aspiration, and endobronchial needle aspiration, is a minimally invasive technique used to diagnose mediastinal and pulmonary masses and to stage lung cancer patients with mediastinal lymphadenopathy. Since it is safe, accurate, and potentially cost-efficient, its use may increase in the coming years. It is important that pathologists who examine cytology specimens understand this procedure, its limitations, and ways that it may be optimized.

Performance of sleep histories in an ambulatory medicine clinic: impact of simple chart reminders.

BACKGROUND: The sleep history is essential to recognizing clinically important sleep disorders, but little is documented about its performance in the primary care setting. STUDY OBJECTIVES: To estimate the frequency of documented sleep histories by medical house officers (HOs) in an ambulatory medicine clinic and to assess whether a chart reminder influences their performance. DESIGN: We reviewed the performance of medical HOs after introduction of a medical record form that included a simple sleep history prompt among reminders relating to health promotion. For each of 108 HOs, we randomly selected a chart with a sleep history prompt and one without. RESULTS: Any sleep history was documented in only 37 of 216 medical records (17%), including 21 of 122 patients (17%) with risk factors for obstructive sleep apnea (OSA). Use of chart reminders was associated with nearly a fivefold increase of sleep histories (29% vs 6%, p < 0.001), and charts with prompts had more notations about specific sleep complaints (2.6 +/- 0.9 vs 1.0 +/- 0.0 notes per patient, p < 0.0001). Sleep histories were recorded less often (p < 0.001) than histories of cigarette smoking or alcohol use. Although 24% of physicians appeared to be influenced by the prompt, sleep problems were included on problem lists of only six patients (3%). Overall, the frequencies of diagnostic studies (1% of all patients, 6% of those with sleep histories) or documented therapeutic recommendations (0%) relating to sleep were low, whether or not chart reminders were used, with sleep testing obtained in only one patient. Sleep interventions were documented less often than smoking cessation or weight loss (p < 0.002). CONCLUSIONS: Sleep histories are seldom documented by medical HOs, even in patients at risk for OSA. Use of a simple chart reminder was associated with an increased frequency of recorded sleep histories, but had no clear impact on diagnosis or treatment. If sleep problems and their management are to be prioritized appropriately, then the obstacles to obtaining sleep histories and to following up cues to sleep disorders must be clarified and overcome.

Venous air embolism from central venous catheterization: a need for increased physician awareness.

OBJECTIVES: To report a series of patients with clinically diagnosed venous air embolism (VAE) and major sequelae as a complication of the use of central venous catheters (CVCs), to survey health care professionals' practices regarding CVCs, and to implement an educational intervention for optimizing approaches to CVC insertion and removal. SETTING: Tertiary care, university-based 806-bed medical center. INTERVENTIONS: We surveyed 140 physicians and 53 critical care nurses to appraise their awareness of the proper management and complications of CVCs. We then designed, delivered, and measured the effects of a multidisciplinary educational intervention given to 106 incoming house officers. MEASUREMENTS AND MAIN RESULTS: Although most physicians (127, 91%) chose the Trendelenburg position for CVC insertion, only 42 physicians (30%) reported concern for VAE. On CVC removal, only 36 physicians (26%) cited concern for VAE. Some physicians (13, 9%) reported elevating the head of the bed during CVC removal, possibly increasing the risk of VAE. Awareness of VAE or its prevention did not correlate with the level of physician training, experience, or specialty. After the educational intervention, concern for and awareness of proper methods of prevention of VAE improved (p < .001). At 6-month follow-up, reported use of the Trendelenburg position continued, but concern cited for VAE had returned to baseline. CONCLUSIONS: There is inadequate awareness of VAE as a complication of CVC use. Focused instruction can improve appreciation of this potentially fatal complication and knowledge of its prevention, but the effect declines rapidly. To achieve a more sustained improvement, a more intensive, hands-on, periodic educational program will likely be necessary, as well as reinforcement through enhanced supervision of CVC insertion and removal practices.

The prognostic significance of passing a daily screen of weaning parameters.

OBJECTIVE: While "weaning parameters" are commonly used to guide removal of mechanical ventilation devices, little information exists concerning their prognostic value. We evaluated whether passing weaning parameters was associated with survival. DESIGN: A prospectively followed cohort of mechanically ventilated patients. SETTING: Medical and coronary adult intensive care units of an 806-bed medical center. PATIENTS: 300 consecutively enrolled mechanically ventilated patients. MEASUREMENTS AND RESULTS: 216 patients who passed a daily screen of weaning parameters were more likely to be extubated successfully (87 vs 30%, p = 0.0001), less likely to require ventilation for > 21 days (3 vs 30%, p = 0.0001), and had a higher survival to hospital discharge (74 vs 29%, p = 0.0001) than 84 patients who never passed the screen. The overall accuracy of the daily screen for predicting successful extubation and in-hospital survival was 82 and 73%, respectively. Multivariate proportional hazards analysis of time until hospital death confirmed the beneficial effect of passing the daily screen (p = 0.01) and of duration of mechanical ventilation (p = 0.001) even after adjustment for differences in severity of illness, age, race, gender, diagnosis, and treatment assignment. While liberation from mechanical ventilation was predictive of survival at any time during the hospital stay (p = 0.001), the prognostic significance of the daily screen for hospital survival was related to how early after intubation it was passed. The difference in survival between patients who had passed and those who had not passed the daily screen was significant for 1 1/2 weeks postintubation but progressively decreased over time. The average time to extubation after passing the daily screen increased from 3 days (range 0 to 56), for those passing within 5 days of intubation, to 8 days (0 to 35), for those passing after 10 days of intubation (r = 0.26, p = 0.001). CONCLUSIONS: Passing a daily screen of weaning parameters is an independent predictor of successful extubation and survival, but its prognostic value decreases over time. Time spent on mechanical ventilation after passing the daily screen presents an important opportunity to optimize liberation from the ventilator.

Mechanical ventilation in a cohort of elderly patients admitted to an intensive care unit.

BACKGROUND: It has been argued that life support for the elderly should be limited to conserve resources. As this population increases, so will the importance of evaluating appropriate use of mechanical ventilation in this group. OBJECTIVE: To determine whether age has an independent effect on the outcomes of patients treated with mechanical ventilation after admission to an intensive care unit (ICU). DESIGN: Prospective cohort study. SETTING: University-based tertiary care medical center. PATIENTS: 63 patients 75 years of age or older and 237 patients younger than 75 years of age enrolled from medical and coronary ICUs. MEASUREMENTS: In-hospital mortality rate, duration of mechanical ventilation, lengths of stay in the ICU and in the hospital, and cost of care. RESULTS: Median duration of mechanical ventilation was 4.2 days (interquartile range, 2.1 to 9.3 days) for patients 75 years of age or older and 6.4 days (interquartile range, 3.4 to 11.4 days) for patients younger than 75 years of age (P = 0.14). When the length of time required to "pass" a daily screening test of weaning variables was used as an indicator of recovery from respiratory failure, elderly patients passed earlier than younger patients (risk ratio, 1.58 [95% CI, 1.13 to 2.22]; P = 0.03). The cost of ICU care was lower for older ($12,822 [CI, $9821 to $26,313] than for younger ($19,316 [CI, $9699 to $39,950]) patients (P = 0.03). Median hospital costs tended to be lower in the older group ($21,292 compared with $29,049; P = 0.17). After adjustment for ethnicity, sex, and severity of illness in a multivariate logistic regression analysis, patient age of 75 years or older was predictive of 1 less day on the ventilator (CI, -2.8 to 1.2 days). Lengths of stay in the ICU (beta-coefficient, -0.5 days [CI, -3.0 to 2.7 days]) and in the hospital (beta-coefficient, 0.3 days [CI, -3.7 to 5.5 days]) did not differ for persons 75 years of age or older after these adjustments (P > 0.1). Intensive care unit and hospital costs, however, were lower for elderly persons (P = 0.02). The in-hospital mortality rate was 38.1% among elderly patients and 38.8% among younger patients (P > 0.2); Cox proportional hazards analysis confirmed that survival did not differ between the two groups (relative risk for older patients, 0.82 [CI, 0.52 to 1.29]). CONCLUSIONS: After adjustment for severity of illness, elderly patients spent similar time on mechanical ventilation and in the ICU and hospital but had a lower cost of care than younger patients. These outcomes are not explained by differences in mortality rate and suggest that mechanical ventilation should not be restricted in elderly patients with respiratory failure on the basis of chronologic age.

Virtual bronchoscopy.

Three-dimensional endoluminal tracheobronchial simulations can be derived successfully from thoracic helical CT scans, and can reproduce the appearances of major endobronchial abnormalities confirmed during FB. The prospects of ever-faster CT scanners (capable of submillimeter resolution) merged with greater computer power make it likely that current versions of virtual bronchoscopy images will seem primitive in the future. Initial descriptive reports suggest great potential, but the startling visual appeal of these 3-D portrayals of a patient's airway and mediastinal anatomy and the prospects of exploring this information in real time do not establish its clinical role. Such virtual bronchoscopy findings are generally predictable on the basis of currently available axial CT images alone. The extent to which these 3-D endobronchial renderings improve the already high predictive values of CT requires critical study. In their patients with lung cancer Cicero et al observed that neither the staging nor diagnosis was modified substantially, but virtual bronchoscopy contributed to enhanced understanding of the pathology of the neoplastic process. Whether this added perspective translates to tangible benefits for patients is an intriguing possibility that has yet to be proved. The unique 3-D endobronchial view may offer particular advantages in some individuals and contribute to the patient's noninvasive evaluation. Because of the already high yield of conventional CT, diagnostic yield alone is not likely to be the sole best measure of this evolving technology. Accordingly, future multidisciplinary research investigations will also need to prospectively address nuances of decision-making and measure appropriate patient outcomes. In these efforts the active dialogue between chest clinician and radiologist will remain essential to defining and realizing the true potential of virtual bronchoscopy.

Large scale implementation of a respiratory therapist-driven protocol for ventilator weaning.

We prospectively investigated the large-scale implementation of a respiratory-therapist-driven protocol (TDP) that included 117 respiratory care practitioners (RCPs) managing 1,067 patients with respiratory failure over 9,048 patient days of mechanical ventilation. During a 12-mo period, we reintroduced a previously validated protocol that included a daily screen (DS) coupled with spontaneous breathing trials (SBTs) and physician prompt, as a TDP without daily input from a physician or "weaning team." With graded, staged educational interventions at 2-mo intervals, RCPs had a 97% completion rate and a 95% correct interpretation rate for the DS. The frequency with which patients who passed the DS underwent SBTs increased throughout the implementation process (p < 0.001). As the year progressed, RCPs more often considered SBTs once patients had passed a DS (p < 0.001), and physicians ordered more SBTs (46 versus 65%, p = 0.004). Overall, SBTs were ordered more often on the medicine than on the surgical services (81 versus 63%, p = 0.001), likely reflecting medical intensivists' prior use of this protocol. Important barriers to protocol compliance were identified through a questionnaire (89 respondents, 76%), and included: Physician unfamiliarity with the protocol, RCP inconsistency in seeking an order for an SBT from the physician, specific reasons cited by the physician for not advancing the patient to a SBT, and lack of stationary unit assignments by RCPs performing the protocol. We conclude that implementation of a validated weaning strategy is feasible as a TDP without daily supervision from a weaning physician or team. RCPs can appropriately perform and interpret DS data more than 95% of the time, but significant barriers to SBTs exist. Through a staged implementation process, using periodic reinforcement of all participants in ventilator management, improved compliance with this large-scale weaning protocol can be achieved.