David J. Powner

Extended somatic support for pregnant women after brain death.

ObjectiveTo review case reports of pregnant women who have been supported after brain death until successful delivery of their infants. From these reports and other literature about brain death, normal physiologic changes of pregnancy, and specific needs for fetal development, recommendations were made to assist in supporting pregnant women after brain death until delivery of a mature fetus who is likely to survive. Data SourcesPersonal files and experiences, MEDLINE review of case reports and publications about physiologic changes present during normal pregnancy and after brain death, and the critical needs for fetal development were included. Data ExtractionEleven reports of ten patients comprise the accumulated clinical experience. Hypotension, requiring fluid administration and inotropic/vasopressor therapy, occurred in all the mothers, and in six cases, was the reason for urgent delivery. The longest period of support was 107 days, from 15 to 32 wks of gestation. Two mothers also became organ donors. Recurrent infections, thermolability, and other complications common to prolonged ICU care were encountered. All infants survived. One had congenital abnormalities caused by phenytoin use by the mother. When followed, all others developed within normal growth and mental variables. These cases plus literature citations noted above were used to develop recommendations for maternal/fetal care. ConclusionPreservation of uterine/placental blood flow is the most important priority during somatic support. Imprecise autoregulation of the uterine vasculature during maternal hypoxemia or hypotension makes this goal a significant challenge. Special considerations for nutrition; medication use; cardiovascular, respiratory, or endocrine therapy; fetal monitoring; hormone replacement; and ethical concerns are discussed.

Differential lung ventilation with PEEP in the treatment of unilateral pneumonia.

A technique for differential lung ventilation via a Carlens tube with inspiratory retardation and the application of separate levels of PEEP to each lung are described in the treatment of a patient with severe unilateral pneumonia. In addition to isolating the diseased lung, this technique permits modification of the distribution of ventilation between the two lungs to improve the ventilation-perfusion ratio and enhance arterial oxygenation. Its clinical application is influenced by the flow characteristics of available mechanical ventilators and by the limitations of the currently available double-lumen endobronchial tubes.

Ventilatory management of life-threatening bronchopleural fistulae. A summary.

The loss of a substantial portion of a critically ill patients inspired tidal volume through a bronchopleural fistula (BPF) may significantly alter the intrapulmonary distribution of ventilation, ventilation-perfusion matching and arterial blood gases. If surgical closure of the fistulous tract is not possible, modifications of traditional ventilatory methods may be necessary to preserve adequate gas exchange. The effect of the methods summarized later in this paper upon the patients mortality and morbidity has not been rigorously analyzed in a large numbers of patients but has been presented in the case studies referenced. Although these techniques might be considered investigational, they can be justified: (1) in the presence of profound hypoxemia and hypercarbia caused by a large BPF, and (2) when reduced gas loss through the fistula is considered an important part of therapy. All the methods discussed below apply in patients requiring endotracheal intubation and mechanical ventilation, whereas some (as indicated in the text) can be used during spontaneous breathing.

Factors during donor care that may affect liver transplantation outcome

Publications are reviewed that identify factors during donor care and characteristics of the donor liver that may be associated with outcome following liver transplantation. The procurement coordinator has the opportunity to influence cold ischemia time, blood pressure, the serum sodium concentration and, perhaps, liver glycogen reserves. These variables may significantly affect postimplantation graft performance and graft or recipient survival. Summaries of those publications comprising this database are presented, and several limitations in their interpretation are discussed.

Teaching critical appraisal during critical care fellowship training: a foundation for evidence-based critical care medicine.

ObjectiveTo determine whether fellowship training in critical care medicine with critical appraisal exercises improves the ability and confidence of fellows to evaluate the medical literature. DesignProspective, interventional pilot study. SettingMultidisciplinary critical care medicine training program at a large university hospital. InterventionFellows were given three didactic sessions covering study design, analysis, and critical appraisal techniques. During the course of the year, each fellow was required to review one article from the literature and present a critique of this article to the group and faculty (Journal Club). Fellows were guided in the preparation of this presentation by one of the critical care medicine faculty. Finally, a written analysis and critique of the article was performed by each fellow. Measurements and Main ResultsA test was given to each fellow at the beginning and end of the academic year. This test consisted of two pairs of articles on therapy for acute lung injury. For the pretest, each fellow was assigned, at random, one pair of articles. Fellows were given 1 hr to review both articles and to fill out a six-point test to assess their ability and confidence to appraise each article. At the end of the year, each fellow was tested on the opposite pair, the tests were graded in a blinded fashion and the results of each test were compared. Six fellows completed both pre- and posttests. These paired results were analyzed separately, whereas results for another six fellows were conducted as an unpaired analysis. Mean scores increased both for the paired analysis (4.1 ± 0.7 vs. 5.1 ± 0.5;p = .015) and for the unpaired analysis (4.3 ± 0.6 vs. 5.0 ± 0.5;p = .012). Self-reported confidence in critical appraisal also increased (2.5 ± 0.5 vs. 3.9 ± 0.7;p = .004 and 2.6 ± 0.5 vs. 3.9 ± 0.6;p < .001, respectively). ConclusionCritical appraisal exercises used in the training of critical care medicine fellows appear to improve both ability and confidence to appraise relevant medical literature.

Compression volume during mechanical ventilation: comparison of ventilators and tubing circuits.

Four ventilators (Puritan-Bennett MA-1 and MA-2, Emerson, and Bear I) and four commercially available disposable and nondisposable tubing circuits (Bennett nondisposable, Becton-Dickinson, Inspiron, and Lifeline) were tested on a lung analog for differences in inspiratory-circuit compression volume. The compression ratio (Rc), equal to the gas volume compressed per cm H2O peak airway pressure, was calculated for each combination of ventilator and circuit at each of four compliance settings (0.15, 0.10, 0.05, 0.01 L/cm H2O) on the analog. Rc values ranged from 0.3 to 4.5 ml/cm H2O at the highest and lowest compliance settings, respectively, accounting for a reduction in delivered tidal volume of up to 20%. The Emerson ventilator with all tubing systems and the Bennett nondisposable circuit with each ventilator demonstrated slightly smaller compression volumes. Application of an inspiratory pause on the Bear I ventilator did not affect its compression characteristics. The clinical importance of compression volume and data from other ventilation systems are reviewed.

Research curricula in critical care fellowships--a survey.

OBJECTIVES To determine curriculum requirements and educational methods used by Critical Care fellowship training programs in fulfilling Residency Review Committee requirements for a research experience during Critical Care subspecialty training. DATA SOURCE Responses from 163 (67%) of the 245 directors of accredited Anesthesiology, Medicine, Pediatric, and Surgical Critical Care fellowship training programs listed in the American Medical Association Graduate Medical Education Directory. DATA EXTRACTION Survey information accepted as valid for each program was tabulated to answer study questions. DATA SYNTHESIS Most (89%) Critical Care programs with 2- or 3-yr curricula meet Residency Review Committee requirements and provide nonclinical time for research. Only 63% of 1-yr curricula from Anesthesiology and Medicine provide a required research experience. Formal instruction in research topics is provided by lecture, journal club, or research conference in approximately 90% of fellowships. Academic productivity from fellowship programs is high, but not correlated with a programs requirement for research. CONCLUSION Compliance with current Residency Review Committee requirements for active participation in research is poor for 1-yr fellowship curricula. Reasons for this failure are discussed and a modified requirement is proposed.

Problems in brain death determination

During the last decade there has been philosophical acceptance of the concept that the state of brain death is equivalent to total patient death. The application of this concept to clinical medicine has been associated with major problems in both the diagnosis of brain death and the medical management of the brain dead patient. In our experience with 176 consecutive cases of suspected brain death over a seven-year period, we have found that a standardized protocol applied by experienced clinicians will minimize these problems.

Compensation for teaching in critical care

Objectives: To determine the financial or nonclinical time critical care program directors or teaching faculty members receive as compensation for their educational activities. To compare compensation types and amounts among critical care specialties and between university vs. nonuniversity sponsoring institutions. Data Sources and Extraction: Survey returns (46%) from critical care fellowship directors listed in the American Medical Association Graduate Medical Education Directory. Information was stratified according to fellowship specialty and type of sponsoring hospital and compared by chi‐square analysis and the Kruskal‐Wallis test. Conclusions: Most program directors (77%) and faculty (82%) receive no specified compensation for education‐related activities. Multidisciplinary programs are more likely to compensate faculty members than other specialty‐specific programs (p = .006). Most programs sponsored by university or military/federal hospitals do not provide specified compensation (79% and 100%, respectively). Overall, community hospital‐based programs provide a greater percentage of compensation to directors and faculty than university programs (for directors, p = .02; odds ratio, 3.85; for faculty, p = .001; odds ratio, 8.4). When compensation is specified, it is most often financial and it averages 18% of the salary (range, 5% to 100%) for directors and 19% of the salary for faculty (range, 5% to 50%). When reduced clinical time is provided (5% of program directors, 2% of faculty), it averages 13% (range, 8% to 18%) for directors and 18% (range, 10% to 25%) for faculty. Alternative methods for assigning educational compensation are discussed.

Declining critical care research publications by authors from U.S. Institutions, 1990-1999.

Purpose To determine whether the proportion of authors from U.S. institutions to those from non-U.S. institutions has changed for published critical care research in three critical care journals over the past ten years. Method The authors of designated critical care clinical or laboratory investigations published from 1990 to 1999 in the three leading U.S. critical care journals, American Journal of Respiratory and Critical Medicine, Chest, and Critical Care Medicine, were evaluated according to the locations of their institutions (U.S. versus non-U.S.) through a review of these publications. Results The proportion of authorship by investigators from U.S. institutions has declined for critical care research publications from 61% of all authors in 1990 to 41% in 1999 (p < .00001). Statistically significant declines in the proportions of authors from U.S. institutions to those from non-U.S. institutions occurred in the American Journal of Respiratory and Critical Care Medicine (p < .05) and Critical Care Medicine (p < .00001), but not in Chest (p = .69). Conclusions The reasons for the decline in authorship by investigators from U.S. institutions are speculative and likely multifactorial. They are, however, consistent with other published data showing limited non-clinical time allocated for education activities for critical care faculty. Anecdotal concerns expressed by many faculty that rising clinical commitments necessitated by current health care and reimbursement pressures preclude research and educational academic activities are supported by these data.