Treatment of forearm fractures.

Fractures of the forearm represent common injuries. Understanding the anatomy and function of the radius, ulna, interosseous membrane, proximal and distal radioulnar joints is critical to appropriate management. Diagnosis can readily be made by examination and radiographs. Well established surgical approaches including the anterior Henry, dorsal Thompson, and ulnar approaches provide excellent access to both the radius and ulna. Multiple fracture patterns are recognized including isolated radius and ulna fractures, combined fractures, Galeazzi fractures, and Monteggia fractures. Surgical management regularly requires open reduction internal fixation with plates (DCP) and screws with vigilance being paid to stable reduction of the proximal and distal radioulnar joints. New directions in the management of forearm fractures include the use of intramedullary fixation and locking plate technology.

Chronic obstructive pulmonary disease management: the evidence base.

In long-term management of stable chronic obstructive pulmonary disease (COPD), a number of medications improve pulmonary function test results. The long-term clinical benefits of those drugs would seem intuitive, but there is very little strong evidence that long-term outcomes in COPD are substantially affected by those drugs. Nevertheless, symptom improvement such as dyspnea reduction is certainly strong reason to use those agents. The 2 most compelling bodies of evidence in stable COPD are for oxygen therapy in the chronically hypoxemic patient and pulmonary rehabilitation to improve exercise tolerance and dyspnea. Inhaled corticosteroids also appear to be useful in patients at risk for frequent exacerbations. In acute exacerbations, the rationale for therapy comes in part from the large body of literature regarding acute asthma therapy. Bronchodilator therapy and corticosteroids both seem to reduce the severity and the duration of exacerbations. Moreover, routine antibiotic use seems beneficial, and the role of noninvasive positive-pressure ventilation with patients suffering impending respiratory failure from acute COPD exacerbations is well supported by the literature.

Intratracheal catheters as drug delivery systems.

Medication delivery into the lungs can be used to provide a high therapeutic index for agents targeted to specific lung diseases. In addition, the lung can be used as a portal of entry for other agents targeted to systemic diseases. Delivery of medications into the lung can be accomplished by either instillation or aerosolization. Instillation approaches are limited by the fluid volume that can be given safely, and instilled liquids distribute according to gravity. In contrast, aerosolization approaches can deliver larger volumes over longer periods and aerosols distribute according to ventilation. In the mechanically ventilated patient, externally generated aerosols have very poor lung delivery because the endotracheal tube functions as a barrier to aerosol passage. Novel aerosol generating systems at the ends of small-diameter catheters that can be placed into the trachea (or beyond) are being developed to address this. In vitro testing has shown these systems to be capable of producing appropriately sized particles, with high rates of lung deposition. These catheters could be coupled with tracheal gas insufflation systems, not only to deliver therapeutic aerosols but also to create water aerosols to supply necessary humidification during tracheal gas insufflation.

High-frequency jet ventilation.

High-frequency ventilation, including HFJV, is an interesting alternative approach to mechanical ventilatory support that may offer benefits in terms of improved gas exchange and lower maximal alveolar distending pressures. Clinical data demonstrating improved outcome exist for neonatal and some forms of pediatric respiratory failure. No such data, however, exist for adults. Important complications can develop, and an extensive learning curve is required for operators to become skilled at delivering proper support safely. Presently, HFV should be limited to only specific applications (e.g., selected neonates, adult airway surgical procedures) and to centers skilled in its use. Considerably more data are required before extensive application, especially in the adult, is warranted.

Aerosolized medications for altering lung surface active properties.

Surface active material is important in the function of both the infant and adult lung. In the premature infant, surfactant depletion results in the requirement for very high distending pressures to open alveoli. As a consequence, shunt, hypoxemia, and right ventricular dysfunction occur. Surfactant replacement, especially by the direct instillation approach, has been proven effective in improving clinical outcome under these circumstances. Problems with surfactant instillation include the "fluid bolus" effect and concerns about optimal distribution of the instilled material. Recent improvements in aerosol systems have created interest in using aerosol delivery to reduce the total dose of surfactant required to treat RDS. In adult acute lung injury, surfactant dysfunction, rather than depletion, is the problem. Simple phospholipid replacement strategies thus may not be effective. Instead, surfactant delivery strategies aimed at regional targeting with surfactants having the necessary associated proteins may be the goal in ARDS. In adults, several instillation trials are underway, but there is also a hope that an aerosol strategy might also be tried. The aerosol route may be particularly useful if a high-efficiency aerosol system (eg, one distal to an endotracheal tube) can be shown to be effective. Other surface active materials exist and there are small studies showing benefit when large instilled doses of these materials are given. These materials, however, have never been studied as aerosols.

Oxygen therapy and exercise response in lung disease.

Lung disease affects exercise performance through a number of mechanisms, including hypoxemia, abnormal ventilatory mechanics, abnormal ventilatory muscles, abnormal ventilatory patterns, abnormal right heart function and subjective dyspnea. Supplemental oxygen improves hypoxemia and thus improves exercise impairment resulting from hypoxemia-related reductions in oxygen delivery. Supplemental oxygen also reduces exercise ventilation. This, in turn, reduces ventilatory muscle work, and the concomitant permissive hypercapnia may have beneficial effects at the cellular level. Additionally, in obstructive disease patients, an improved ventilatory pattern may reduce air trapping. Supplemental oxygen may also improve right ventricular dysfunction in patients with underlying right ventricular dysfunction. Finally, supplemental oxygen may reduce dyspnea caused by oxygen-related carotid body activity. Important questions remain. First, is long-term oxygen use of benefit in patients with only exercise hypoxemia? Second, is exercise conditioning possible in patients with exercise hypoxemia? Third, does supplemental oxygen enhance exercise conditioning efforts in those patients with CLD but without exercise hypoxemia? If the answer to this last question is yes, what selection criteria should be used to identify those who would benefit? The answers to all of these questions will have enormous impact on our approach to the optimal management of CLD patients.

Long-term oxygen therapy: conference summary.

With Jan's presentation, the conference concluded. In looking back on it, I think it is obvious that the group heard a very comprehensive, state-of-the-art review of this very important topic. Obviously, LTOT has enormous clinical and financial impact for millions of patients around the world. Indeed, LTOT is one of the few therapies available that has clearly been shown in randomized controlled trials to impact mortality. There are many questions that remain, however. To me, the most important of these questions involve the diagnosis and management of patients who do not have resting hypoxemia but who do have NOD and/or XOD. How aggressively should we "screen" for these conditions? If we find them, do we treat continuously or just during the hypoxemic episodes? What is the role of supplemental oxygen during rehabilitative exercises (including usage in patients who don't become hypoxemic)? The answers to these questions will clearly have substantial clinical and financial impact. Other memorable aspects of this conference included the tireless efforts of Ray Masferrer to pull this conference off, the special camaraderie of the participants that made the discussions so productive, and the lovely location that gave the conference an atmosphere of high quality. I'd like to recognize and thank two important groups. First, the American Association for Respiratory Care did a superb job of organizing the conference and providing the journal Respiratory Care as a forum to publish the proceedings. Second, our 3 industry sponsors not only provided critical funding support but also gave the group important perspectives during many of the discussions. These kinds of industry-profession collaborations benefit everyone. Finally, I'd like to extend my congratulations to all the speakers for jobs well done and to thank them for making my job as summarizer an enjoyable one.

High-frequency ventilation.

High-frequency ventilation (HFV) provides respiratory gas exchange using positive airway pressure-driven tidal breaths that are often smaller than anatomic dead space and breathing frequencies several times faster than normal. Gas transport with HFV involves nonconvective mechanisms such as Taylor dispersion, coaxial flow, and augmented diffusion. Devices to deliver HFV include the jet (an airway injector delivers jet pulses) and the oscillator (a piston oscillates a bias flow of fresh gas). The conceptual advantage to HFV is that maximal airway pressures are limited by the small tidal breath and lung recruitment is optimized by the intrinsic positive end expiratory pressure effect. Outcome has been shown to be improved in pediatric patients at risk for volutrauma. Adult outcome data are still lacking.

Tracheal gas insufflation.

Tracheal gas insufflation (TGI) is an adjunct to mechanical ventilation that reduces CO (2) present in the anatomic deadspace. This is accomplished by flowing fresh gas (typically 6-10 lpm) directly into the trachea via a catheter placed into the endotracheal tube positioned at the distal end or by an embedded catheter in the wall of a specially designed endotracheal tube. This is thought to improve gas mixing because of the turbulent flow created at the tip of the catheter. There are two methods of gas flow delivery and cycling. Gas flow may be delivered directly toward the carina or in a reverse flow fashion. Cycling of TGI flow may be just during exhalation or during both inhalation and exhalation. A system integrated into the monitoring and controls of a mechanical ventilator could eventually prove the safest and most effective. However, currently there are no FDA-approved devices for TGI administration. It is critical to monitor the adverse effects (triggering, auto-PEEP [positive end expiratory pressure], air trapping, and patient comfort) created by the additional flow introduced into the ventilator circuit, while balancing the CO (2) clearance. There are limited data, mostly from animal studies. However, the trials done in both animal and humans are promising with regard to effective CO (2) elimination and avoidance of unacceptably high peak airway pressures. Available equipment has limited studies with infants. Even within the adult population, much work needs to be done to determine the optimal catheter position, the most appropriate TGI flow characteristics, and improve the safety of TGI.

Mechanical ventilation strategies for lung protection.

A large body of animal literature has shown that lungs stretched beyond their normal maximum are likely to be injured and release inflammatory cytokines into the systemic circulation. Moreover, this injury seems to be compounded if alveolar collapse also occurs. This has give rise to the notion that adequate positive end expiratory pressure (PEEP) to prevent derecruitment coupled with a tidal volume-PEEP combination that limits maximal distention to below the normal maximum is the ideal way to provide positive pressure ventilatory support. Some have argued that static pressure-volume plots to describe upper and lower inflection points are particularly important in implementing this approach. Supporting this concept is the recently completed NIH trial showing improved survival in acute respiratory distress syndrome (ARDS) when a small tidal volume strategy was used.

Advances in infection control: ventilator-associated pneumonia.

Mechanically ventilated patients are 6-21 times more likely to develop nosocomial pneumonia. It is estimated that between 6% and 52% of ventilated patients develop ventilator-associated pneumonia (VAP) with attributable mortality of 27-51%. Certain high risk organisms carry higher mortality (e.g., Pseudomonas aeruginosa and Acinetobacter spp.). Aspiration of colonized orodigestive secretions is the commonly recognized route of infection, whereas inhalation of contaminated aerosol hematogenous spread and direct infection are less common. Gram-negative pathogens are responsible for 40-60% of VAP, whereas gram-positive pathogens cause 15-20%, and it is commonly polymicrobial. Diagnosis remains difficult, and studies showed that early appropriate treatment can improve patient outcome. Better understanding of the pathogenesis and risk factors is important for implementing more effective infection control measures. Clinical trials evaluating outcome will help in assessing current and future preventive and therapeutic measures.

Psychological and cognitive outcomes of a randomized trial of exercise among patients with chronic obstructive pulmonary disease.

Exercise rehabilitation is recommended increasingly for patients with chronic obstructive pulmonary disease (COPD). This study examined the effect of exercise and education on 79 older adults (M age = 66.6 +/- 6.5 years; 53% female) with COPD, randomly assigned to 10 weeks of (a) exercise, education, and stress management (EXESM; n = 29); (b) education and stress management (ESM; n = 25); or (c) waiting list (WL; n = 25). EXESM included 37 sessions of exercise, 16 educational lectures, and 10 weekly stress management classes. ESM included only the 16 lectures and 10 stress management classes. Before and after the intervention, assessments were conducted of physiological functioning (pulmonary function, exercise endurance), psychological well-being (depression, anxiety, quality of life), and cognitive functioning (attention, motor speed, mental efficiency, verbal processing). Repeated measures multivariate analysis of variance indicated that EXESM participants experienced changes not observed among ESM and WL participants, including improved endurance, reduced anxiety, and improved cognitive performance (verbal fluency).