Mark A. Kelley

Critical care delivery in the United States: distribution of services and compliance with Leapfrog recommendations.

Objectives:To describe the organization and distribution of intensive care unit (ICU) patients and services in the United States and to determine ICU physician staffing before the publication and dissemination of the Leapfrog Group ICU physician staffing recommendations. Design and Setting:Stratified, weighted survey of ICU directors in the United States, performed as part of the Committee on Manpower for the Pulmonary and Critical Care Societies (COMPACCS) study. Using lenient definitions, we defined an ICU as “high intensity” if ≥80% of patients were cared for by a critical care physician (intensivist) and defined an ICU as compliant with Leapfrog if it was both high-intensity and providing some form of in-house physician coverage during all hours. Subjects:Three hundred ninety-three ICU directors. Interventions:None. Measurements and Main Results:We obtained a 33.5% response rate (393/1,173). We estimated there were 5,980 ICUs in the United States, caring for approximately 55,000 patients per day, with at least one ICU in all acute care hospitals. The predominant reasons for admission were respiratory insufficiency, postoperative care, and heart failure. Most ICUs were combined medical-surgical ICUs (n = 3,865; 65%), were located in nonteaching, community hospitals (n = 4,245; 71%), and were in hospitals of <300 beds (n = 3,710; 62%). One in four ICUs were high-intensity (n = 1,578; 26%), half had no intensivist coverage (n = 3,183; 53%), and the remainder had at least some intensivist presence (n = 1,219; 20%). High-intensity units were more common in larger hospitals (p = .001) and in teaching hospitals (p < .001) and more likely to be surgical (p < .001) or trauma ICUs (p < .001). Few ICUs had any in-house physician coverage outside weekday daylight hours (20% during weekend days, 12% during weeknights, and 10% during weekend nights). Only 4% (n = 255) of all adult ICUs in the United States appeared to meet the full Leapfrog standards (a high-intensity ICU staffing pattern plus dedicated attending coverage during daytime plus dedicated coverage by any physician during nighttime). Conclusions:ICU services are widely distributed but heterogeneously organized in the United States. Although high-intensity ICUs have been associated previously with improved outcomes, they were infrequent in our study, especially in smaller hospitals, and virtually no ICU met the Leapfrog standards before their dissemination. These findings highlight the considerable challenge to any efforts designed to promote either 24-hr physician coverage or high-intensity model organization.

DIAGNOSING PULMONARY EMBOLISM : NEW FACTS AND STRATEGIES

PURPOSE To provide a clinical approach to the diagnosis of pulmonary embolism. DATA IDENTIFICATION An English-language literature search using MEDLINE (1982 to 1990) and bibliographic reviews of textbooks and review articles. STUDY SELECTION In addition to several reviews, studies that evaluated the diagnostic technology of pulmonary embolism were selected. Preference was given to studies with a prospective design, particularly those done within the past decade. DATA EXTRACTION Studies were assessed independently by three unblinded observers. Data were chosen to describe the efficacy of diagnostic technology on the basis of disease prevalence, sensitivity and specificity, and predictive value. RESULTS OF DATA ANALYSIS A normal lung scan or pulmonary angiogram rules out the diagnosis of clinically important pulmonary embolism with at least 95% certainty. Lung scan interpretations indicating high or low probability have approximately a 15% error in diagnosing or ruling out pulmonary embolism. The accuracy of either scan result improves when the clinical suspicion of pulmonary embolism matches the lung scan result. Serial impedance plethysmography of the lower extremities may exclude thromboembolism with 95% certainty in patients without high-probability lung scan results or cardiopulmonary disease. CONCLUSIONS The combination of clinical suspicion and the results of the lung scan and impedance plethysmography appear to offer acceptable diagnostic accuracy in evaluating many patients suspected of having pulmonary embolism. The usefulness of this approach for patients with cardiopulmonary disease is still unknown.

Resting single-breath diffusing capacity as a screening test for exercise-induced hypoxemia

Recent reports in selected patients have suggested that a reduced resting single-breath carbon monoxide diffusing capacity may be associated with a fall in arterial oxygen saturation during exercise. To determine if the diffusing capacity could serve as a screening test for changes in oxygen saturation in an unselected population, results of exercise studies were examined in 106 patients consecutively referred to an exercise laboratory. Nearly half of the patients underwent exercise testing to evaluate interstitial disease whereas the remainder were referred for unexplained dyspnea or for disability evaluations. Arterial desaturation was seen within all patient subgroups and was closely associated with reduced diffusing capacity. For detecting changes of 4 percent or more in oxygen saturation, a diffusing capacity of less than 50 percent of predicted gave the best combination of sensitivity (89 percent) and specificity (93 percent), whereas a diffusing capacity of 60 percent or less of predicted was 100 percent sensitive and 64 percent specific. For detecting lesser degrees of desaturation, sensitivities were slightly reduced but specificities were preserved. Thus, a diffusing capacity of less than 50 percent of predicted was associated with substantial arterial desaturation during exercise, whereas patients with a diffusing capacity of more than 60 percent of predicted had no desaturation during exercise. These results suggest that the resting diffusing capacity can serve as a screening test for exercise-induced hypoxemia in an unselected population.

The Hospitalist: A New Medical Specialty?

Economic forces have stimulated a growing role for physician hospitalists in caring for patients hospitalized by other physicians, and the question of whether hospital care constitutes a new medical specialty has been raised. Three recently recognized specialties-emergency medicine, family practice, and critical care-originated from trends in medical practice. All three fulfill the major criteria for a medical specialty: scientific legitimacy, the development of new training pathways, and the existence of academic departments. The hospitalist movement is currently underdeveloped in each of these areas. By training, most hospitalists are internists who are well prepared to care for inpatients. Internal medicine must determine how this new movement fits into the traditional framework of general internal medicine and medical subspecialties. Until it does, the future of inpatient medicine as a recognized specialty will remain uncertain.

Hypercapnic ventilation during exercise: Effects of exercise methods and inhalation techniques

The effect of exercise on the ventilatory response to inhaled CO2 is uncertain because previous studies using different techniques have come to different conclusions. We undertook to resolve this problem by using multiple techniques and confining our study to a uniform level of mild exercise (VO2 = 10 ml/kg min). One group of subjects exercised on a treadmill and was tested with both rebreathing and steady-state CO2 methods. A second group exercised on a bicycle while using the rebreathing method. We found that the ventilatory response to CO2 was unchanged by mild exercise, regardless of the method used for CO2 inhalation or the technique used for exercise. These results indicate that under controlled conditions mild exercise does not produce any change in ventilatory sensitivity to CO2.

Tracheobronchial Inflammatory Myofibroblastoma A Locally Invasive, Potentially Recurrent Neoplasm

Clinicopathologic findings in three cases of inflammatory myofibroblastomas (so-called inflammatory pseudotumors) of the trachea and bronchi are reported. In all cases the myofibroblastic nature of the spindle cell proliferation was revealed using electron microscopic and immunohistochemical methods. In two of these cases, in which the lesions were incompletely excised to conserve the wall of the airways and the normal lungs, several recurrences over a period of many years were successfully managed endoscopically. These potentially recurring and locally invasive myofibroblastic lesions should be treated as low-grade neoplasms rather than reactive processes. However, if complete excision is not feasible, lung-sparing management is warranted because myofibroblastomas progress slowly and recurrences can be readily detected by bron choscopy. Int J Surg Pathol 2(2):93-98, 1994.

Supporting primary care medical education

A number of fundamental issues must be considered in preparing the education system to produce more primary care physicians. Governmental controls and redirection of resources will force significant changes in the structuring of approaches to both undergraduate and graduate education in primary care. Particularly challenging will be restructuring and funding medical student programs in primary care, given a nearly certain requirement that more than 50% of medical school graduates enter primary care disciplines. Institutions will need to make strategic resource allocations to compete for the funding once the allocation process begins. Educational institutions will also face a cultural adaptation to primary care as an educational priority. This paper presents a model to study costs and funding for residency programs as they move from the traditional inpatient orientation to an outpatient focus. The authors suggest that for medical student education, the development of large academic health care systems may make funding primary care education more feasible.