Exacerbate infection

Numerous concerns about the safety of hemoglobin preparations have been presented in the literature. Some of the historical safety concerns have been addressed and are no longer issues with respect to the hemoglobin formulations now in advanced clinical trials. For example, effects such as neutrophil and macrophage activation, the formation of microthrombi, and platelet aggregation appear to have been eliminated from these Hb formulations. However, new safety concerns, centering on effects that have been observed clinically, have been raised. Three principal concerns will be discussed here 1) Mb s pressor activity 2) the potential for acellular Hb to exacerbate injury and 3) the potential for Hb to potentiate or exacerbate infection. 

BALB/c animals display IL-12 p40 mRNA, in apparent contrast to PMN from the genetically susceptible C57BL/6 mouse strain [73]. Neutrophil depletion of BALB/c mice exacerbates infection. This is accompanied by decreased Thl cytokines (IL-12 p40, IFN-7, TNF-a) and increases in the IL-10 response in spleens of infected animals, suggesting a Thl to Th2 switch [73]. In contrast, during T. cruzi infection of susceptible C57BL/6 mice, neutrophil depletion induces resistance to disease and enhances Thl cytokine production. Neutrophils have also been implicated in induction of the CD4-I- Th2 response in L. major-infected BALB/c mice [85]. Thus, the early burst of IL-4 that instructs Th2 differentiation in this model is prevented by neutrophil depletion, and draining lymph node T cells remain IL-12-responsive, unlike cells from nondepleted mice. 

American trypanosomiasis, known as Chagas Disease, is limited to South and Central America, where it affects 16—18 million people aimuaHy in an area where 90 million are at risk. Although only an estimated 1% of infected individuals contract the disease, poverty and poor housing exacerbate it. There is a particularly high incidence of the disease in children. 

The use of antibiotics is not recommended, except for the treatment of infectious exacerbations of COPD and other bacterial infections. Influenza vaccines decrease illness and death in COPD patients. Pneumococcal vaccination is also recommended. 

Picornavimses are small, nonenveloped RNA vimses. Members of this family include rhino- and enteroviruses, which are responsible for a variety of human diseases (viral respiratory infection, viral meningitis, myocarditis, pericarditis, encephalitis, chronic meningoencephalitis, herpangina, otitis media, neonatal enteroviral disease, and acute exacerbations of asthma). 

M ore than 200 viruses have been identified as capable of producing disease Acute viruses, such as the common cold, have a rapid onset and quick recovery. Chronic viral infections, such as acquired immunodeficiency syndrome (AIDS), have recurrent episodes of exacerbations (increases in severity of symptoms of the disease) and remissions (periods of partial or complete disappearance of the signs and symptoms). Display 14-1 describes the viruses discussed in this chapter. 

Adverse reactions associated with administration of the corticosteroid ophthalmic preparations include elevated IOP with optic nerve damage, loss of visual acuity, cataract formation, delayed wound healing, secondary ocular infection, exacerbation of comeal infections, dry eyes, ptosis, blurred vision, discharge, ocular pain, foreign body sensation, and pruritus. 

Opiate drug exposure has a significant impact on HIV infection as well as progression to HIV-associated dementia. On a cellular level it is comprehendible that drugs of abuse such as opioids would reduce the threshold for neurotoxicity such that a marginally toxic insult would now be exacerbated and lead to cell death or injury... 

Mild-to-moderate stress (minor infection, disease exacerbation)... 

Acute exacerbations usually result from an allergen or a viral infection... 

Viral infections are the most common cause of increased asthma symptoms and asthma exacerbations. 

Routine antibiotic use is not warranted because the primary infectious agents associated with asthma exacerbations are viruses.2,3 Antibiotics should be reserved for situations when bacterial infection is strongly suspected (e.g., fever and purulent sputum, pneumonia, and suspected sinusitis). 

An exacerbation is a sustained worsening of the patient s symptoms from his or her usual stable state that is beyond normal day-to-day variations. It is acute in onset and sufficient to warrant a change in management. Commonly reported symptoms are worsening of dyspnea, increased sputum production, and change in sputum color. The most common causes of an exacerbation are respiratory infection and air pollution, but the cause cannot be identified in about one-third of severe exacerbations.2... 

Treatment depends on the symptoms and severity of the exacerbation. Mild exacerbations can often be treated at home with an increase in bronchodilator therapy with or without oral corticosteroids (Fig. 12-3). Antibiotics are indicated only if there are clinical signs of airway infection (e.g., increased volume and change in color of sputum and/or fever). Moderate to severe exacerbations require management in the... 

The role of bacterial infections in COPD exacerbations is controversial, and there are limited data on the efficacy of antibiotics in treating COPD exacerbations. Recent studies suggest that bacteria cause 40% to 50% of acute exacerbations.31 Antibiotics should be used in patients with COPD exacerbations who have either of the following characteristics (1) at least two of three cardinal symptoms increased dyspnea, sputum volume, or sputum purulence or (2) a severe exacerbation requiring mechanical ventilation.2... 

Sethi S, Murphy TF. Acute exacerbations of chronic bronchitis new developments concerning microbiology and pathophysiology— impact on approaches to risk stratification and therapy. Infect Dis Clin North Am 2004 18 861-882. 

Airway clearance therapy is a necessary routine for all CF patients to clear secretions and control infection. It is typically performed once or twice daily for maintenance care and three or four times per day for acute exacerbations. 

Clinical features Acute exacerbation of anemia due to sequestration of large blood volume by the spleen. More commonly seen in patients with functioning spleens (e.g., infants and adults with HbSC disease) onset often is associated with viral or bacterial infections recurrences are common and can be fatal. 

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