Respiratory care clinics of North America最新文献

The metabolic demands of the body, including consumption of oxygen and removal of carbon dioxide, vary widely in health and disease. Ventilation must adjust to meet these demands and accommodate volitional and behavioral activities. Control of breathing depends on a complex and intricate feedback control system that integrates these automatic and volitional aspects of ventilation. Sensors, including chemoreceptors and lung volume receptors, relay information to a central controller located primarily in the medulla. The central controller integrates this information and determines the level of activation of the effectors (the respiratory motoneurons and muscles), which affects ventilation and gas exchange. Inputs from suprapontine structures, including the cerebral cortex, are also important in integrating volitional aspects of breathing into the control system.

Ventilator performance can be tied to the individual systems that control delivery of pressure, volume, and flow. Clinician's need not be engineers but should understand how individual device mechanics and algorithms can affect patient ventilator synchrony.

Successful guideline implementation programs need to understand local barriers, incorporate multiple component interventions, and proceed within a framework of continuous quality improvement. We found few intervention studies to improve CAP guideline adherence and no controlled studies that used certain practice changes strategies that have proven effective for other conditions, such as face-to-face educational outreach, use of local opinion leaders, and individualized audit with peer-comparison feedback. Future studies in CAP management need to use rigorous study designs, use multiple evidence-based strategies to change practice, and convincingly demonstrate to front-line health care providers that the suggested interventions are safe and improve patient outcomes. Paper does not change practice, and the creation and mailing out of a practice guideline for the treatment of CAP is only the first necessary step in translating good evidence into everyday clinical practice.

It seems that with climatic and geoecologic changes, Hantaviruses have re-emerged as human pathogens related to increases in interaction between humans and rodent reservoirs. Infection with SNV in North America and the Andes virus in South America can produce infection manifest initially as a flu-like illness. In the setting of a history of possible exposure to rodents or their excreta, clinical symptoms and laboratory clues such as thrombocytopenia should raise the suspicion of HPS. Clinical deterioration can be rapid, so patients should be hospitalized and transported to tertiary care centers where mechanical ventilation is available if necessary. Presumptive treatment for other forms of sepsis should be considered before confirmation of diagnosis. Survival seems to be determined in part by viral and host factors. Canadian and South American data suggest that there may be species variations influencing clinical manifestations and course of disease. Because the pathogenesis seems to be based on immunologic injury, future treatments will likely focus on interventions other than antiviral medications. Prevention strategies should be emphasized, particularly when recognized climatic conditions favor rodent abundance. Physicians should remain alert to the possibility of such a diagnosis when evaluating a patient with CAP and should request appropriate serology while supporting the patient in a closely monitored setting. The declining mortality rates seen over the past decade may be a consequence of improved medical management or better recognition of cases, including those less severe than originally described.

Many patients with CAP are seen in the ER and treated as outpatients.History, physical examination, selected lab tests, and chest radiography must be routinely undertaken in patients with "presumptive" pneumonia to make the diagnosis and allow for appropriate risk stratification. There is wide disagreement among physicians on the presence or absence of CAP on chest radiographs, and a chest radiograph that shows "no pneumonia" may not be sufficient to rule out the diagnosis. Furthermore, even patients with "ambulatory" pneumonia may have important laboratory abnormalities and a moderate risk of hypoxemia. Diabetes mellitus and stress hyper-glycemia are important comorbidities and must be accounted for in any rational discharge plan. All of the aforementioned observations need to be understood in the context of an increasingly older and frailer patient population that may still be eligible for appropriate outpatient treatment. It is likely that guidelines and clinical pathways for outpatient treatment of CAP that standardize medical care and mandate careful and regular follow-up of patients discharged home will decrease unnecessary practice variation while improving the overall quality of care.

Tuberculosis (TB) is often mistaken for community-acquired pneumonia (CAP). To avoid missing the diagnosis, we recommend that any CAP patient with upper lobe infiltrate, cavitation, miliary pattern, hemoptysis or >1 month of any of cough, fever, malaise,weakness, night sweats, or significant weight loss, should have sputa submitted for Mycobacterium tuberculosis smear and culture. Any CAP patient failing or relapsing after empiric therapy should be investigated for TB. In the presence of HIV with low CD4 count (< or = 200 cells/mL), the presentation may be atypical, and therefore sputa should be submitted for M tuberculosis. Any HIV patient, regardless of CD4 count, with a known history of positive tuberculin skin test, previous TB, or recent exposure to TB, who presents with CAP, should be investigated for TB.

Using the Internet, it is possible to perform multicenter international projects easier, faster, and less expensive than in the past. Making large international databases available to investigators from around the world will greatly expand the possibilities to obtain new knowledge in the areas of community-acquired pneumo-nia (CAP) research and quality. By closing the gap between clinical research and clinical practice, the management of patients with CAP will improve worldwide.

Some of the key features of Hendra and Nipah viruses are summarized in Table 1. The appearance of these new viruses over the last 10 years emphasizes a number of issues. (1) Epidemics of human infectious diseases can occur unexpectedly and with high impact in terms of morbidity and mortality. (2) We do not know what epidemiologic factors conspire to allow these viruses to stray out of their bat reservoirs into the two different intermediate hosts (horses and pigs) and then into humans. (3) We do not know how long these viruses have been present in the bat population, where they originated from, or if they are present in other parts of the world. (4)There may be other viruses waiting for similar opportunities to cross species.(5) It is unlikely that we have seen the last of these and related viruses.