Efficacy and cost comparisons of bronchodilatator administration between metered dose inhalers with disposable spacers and nebulizers for acute asthma treatment.

BACKGROUND: Despite demonstration of equivalent efficacy of beta agonist delivery using a metered dose inhaler (MDI) with spacer vs. nebulizer in asthma patients, use of a nebulizer remains standard practice. OBJECTIVES: We hypothesize that beta agonist delivery with a MDI/disposable spacer combination is an effective and low-cost alternative to nebulizer delivery for acute asthma in an inner-city population. METHODS: This study was a prospective, randomized, double-blinded, placebo-controlled trial with 60 acute asthma adult patients in two inner-city emergency departments. Subjects (n = 60) received albuterol with either a MDI/spacer combination or nebulizer. The spacer group (n = 29) received albuterol by MDI/spacer followed by placebo nebulization. The nebulizer group (n = 29) received placebo by MDI/spacer followed by albuterol nebulization. Peak flows, symptom scores, and need for rescue bronchodilatator were monitored. Median values were compared with the Kolmogorov-Smirnov test. RESULTS: Patients in the two randomized groups had similar baseline characteristics. The severity of asthma exacerbation, median peak flows, and symptom scores were not significantly different between the two groups. The median (interquartile range) improvement in peak flow was 120 (75-180) L/min vs. 120 (80-155) L/min in the spacer and nebulizer groups, respectively (p = 0.56). The median improvement in the symptom score was 7 (5-9) vs. 7 (4-9) in the spacer and nebulizer groups, respectively (p = 0.78). The median cost of treatment per patient was $10.11 ($10.03-$10.28) vs. $18.26 ($9.88-$22.45) in the spacer and nebulizer groups, respectively (p < 0.001). CONCLUSION: There is no evidence of superiority of nebulizer to MDI/spacer beta agonist delivery for emergency management of acute asthma in the inner-city adult population. MDI/spacer may be a more economical alternative to nebulizer delivery.

Effects of chromogranin A deficiency and excess in vivo: biphasic blood pressure and catecholamine responses.

OBJECTIVE: The phenotype of the chromogranin A (Chga) null (knockout) mouse is hypertensive. However, hypertensive humans and spontaneously hypertensive rats display elevated CHGA expression. This study addresses the paradox that both ablation and elevation of CHGA result in hypertension. METHODS: Mice with varying copy number of the CHGA gene were generated. In these mice CHGA, catecholamine and blood pressure (BP) were measured. Also a cohort of healthy human individuals was stratified into tertiles based on plasma CHGA expression and phenotyped for characteristics including their BP response to environmental (cold) stress. RESULTS: The mice displayed a direct CHGA gene dose-dependent (0-4 copies/genome) activation of CHGA expression in both plasma and adrenal gland, yet the BP dependence of CHGA gene dose was U-shaped, maximal at 0 and four copies of the gene, whereas minimal at two copies (i.e., the wild-type gene dosage). Plasma catecholamine showed a parallel U-shaped dose/response in mice, whereas adrenal epinephrine exhibited a reciprocal (inverted) U-shaped response, suggesting dysregulated neurotransmission at both extremes of CHGA expression. The human individuals also showed a nonlinear relationship between CHGA expression and pressor responses to environmental (cold) stress, that were maximal in the highest and lowest tertiles, though basal BPs did not differ among the groups. The human CHGA tertiles also differed in epinephrine secretion as well as degree of CHGA processing to catestatin (catecholamine release-inhibitory peptide derived from CHGA processing). CONCLUSION: Thus, across mammalian species, an optimal amount of CHGA may be required to establish appropriate catecholamine storage and release, and hence BP homeostasis.

Replacing an academic internal medicine residency program with a physician assistant--hospitalist model: a comparative analysis study.

This study describes a comparative analysis of replacing medical residents with physician assistants and hospitalists on patient outcomes in a community hospital. Prospective data during the physician assistants-hospitalists service for 2 years was compared with 2 years of retrospective data of the medical residents model. Outcome measures included mortality, adverse events, readmissions, and patient satisfaction. For physician assistants- hospitalists versus medical residents models, all-cause and case mix index-adjusted mortality was 107/5508 (1.94%) and 0.019 versus 156/5458 (2.85%) and 0.029, respectively (P < or = .001). The adverse event cases were 9 versus 5 ( P = .29), and the readmission rate within 30 days was 64 versus 69 (P = .34). Patient satisfaction was 95% versus 96% (P = .33). Quality of care provided by the physician assistants-hospitalists model was equivalent. All-cause and case mix index- adjusted mortality was significantly lower during the physician assistants-hospitalists period.Although the application of these findings to other institutions requires further study, the authors found no intrinsic barriers that would impede implementation elsewhere.

Lyme carditis: sequential electrocardiographic changes in response to antibiotic therapy.

Lyme disease is a tick-borne spirochetal infection that may involve heart. The cardiac manifestations of Lyme disease including varying degrees of atrioventricular heart block occur within weeks to months of the infecting tick bite. This report describes a 43 year-old man with Lyme carditis who presented with complete heart block. The heart block resolved with ceftriaxone therapy. Lyme carditis should be considered in the differential diagnosis in patients who present with new onset advanced heart block.

Room air entrainment during beta-agonist delivery with heliox.

Studies of the efficacy of heliox in patients with severe asthma have shown mixed results. Among the factors that are responsible for variable outcomes, the failure of heliox delivery systems to prevent room air entrainment (RAE) during beta-agonist delivery is probably the most critical. While keeping the rotameter flow rate (FR) of heliox mixed 70:30 to a nebulizer at 10 L/min, the FR of heliox from a second gas source to a T-connector (TC) was increased during the delivery of the beta-agonist with a conventional T-nebulizer delivery system (TNDS). A negative peak inspiratory flow (pneumotachometer reading) or a helium concentration of < 70% (quadralizer reading) were indicators of RAE. RAE was tested during spontaneous tidal breathing and acute asthma. A rotameter FR of 10 L/m to the nebulizer with no flow from a second gas source to a TC (conventional TNDS) resulted in a significant drop in helium concentration during tidal breathing (46.2%) and acute asthma (27.5%) due to RAE. This degree of helium dilution can negate the beneficial effects of heliox to lung mechanics almost completely. A rotameter FR of 10 L/m each to a nebulizer and a TC resulted in a helium concentration 69.8% during tidal breathing (no RAE), but 49% (significant RAE) during asthma events. A rotameter FR of 15 L/m (pressure regulator setting, 100 lbs per square inch) to a TC, while maintaining a rotameter FR of 10 L/m to a nebulizer prevented RAE during asthma (helium concentration, 69.9%). Conventional TNDS may be used to deliver the beta-agonist with heliox during asthma without RAE.