May is asthma awareness month, and with summer right around the corner, a study shows that doctors may be closer to understanding why patients with mild asthma have such difficulty breathing during hot, humid weather. The study, appearing in the June print issue of the American Journal of Respiratory and Critical Care Medicine, found that patients who inhaled an asthma drug before breathing in hot, humid air were able to prevent airway constriction that volunteers without asthma did not experience in the same environment... (Source: Health News from Medical News Today)

We develop optimal respiratory airflow patterns using a nonlinear multicompartment model for a lung mechanics system. Specifically, we use classical calculus of variations minimization techniques to derive an optimal airflow pattern for inspiratory and expiratory breathing cycles. The physiological interpretation of the optimality criteria used involves the minimization of work of breathing and lung volume acceleration for the inspiratory phase, and the minimization of the elastic potential energy and rapid airflow rate changes for the expiratory phase. Finally, we numerically integrate the resulting nonlinear two-point boundary value problems to determine the optimal airflow patterns over the inspiratory and expiratory breathing cycles. (Source: Advances in Pharmacological Sciences)

Extracorporeal membrane oxygenation (ECMO) for support of adult patients with acute lung failure has been a vigorously debated topic among critical care professionals. As researchers continue to investigate its risks and benefits, indications for use are slowly expanding. Increasing wait times for lung transplants and the poor outcomes associated with endotracheal intubation warrant new support strategies for patients with end-stage lung disease. The authors of an article published in the April 2012 issue of the American Journal of Respiratory and Critical Care Medicine examined the role of ECMO as a bridge to lung transplantation... (Source: SCCM RSS News)

HYPOCAPNIA AND HYPERCAPNIA ARE PREDICTORS FOR ICU ADMISSION AND MORTALITY IN HOSPITALIZED PATIENTS WITH COMMUNITY-ACQUIRED PNEUMONIA.

Chest. 2012 Jun 7;

Authors: Laserna E, Sibila O, Aguilar PR, Mortensen EM, Anzueto A, Blanquer JM, Sanz F, Rello J, Marcos PJ, Velez MI, Aziz N, Restrepo MI

Abstract
ABSTRACT INTRODUCTION:The purpose of our study was to examine in patients hospitalized with community-acquired pneumonia (CAP) the association between abnormal PaCO2 and ICU admission and 30-day mortality. METHODS:A retrospective cohort study was conducted at two tertiary teaching hospitals. Eligible subjects were admitted with a diagnosis of CAP. Arterial blood gas analyses were obtained with measurement of PaCO2 on admission. Multivariate analyses were performed using 30-day mortality and ICU admission as the dependent measures. RESULTS:Data were abstracted on 453 subjects with a documented ABG. 189 patients (41%) had normal PaCO2 (35-45 mmHg), 194 patients (42%) have a PaCO2 <35 mmHg (hypocapnic) and 70 patients (15%) had a PaCO2>45 mmHg (hypercapnic).In the multivariate analysis after adjusting for severity of illness, hypocapnic patients had greater 30-day mortality (Odds ratio [OR]=2.84; 95% confidence interval [CI]; 1.28-6.30) and higher need for ICU admission (OR=2.88; 95% CI; 1.68-4.95) compared to patients with normal PaCO2. In addition, hypercapnic patients had a greater 30-day mortality (OR=3.38; 95% CI; 1.38-8.30) and higher need for ICU admission (OR=5.35; 95% CI; 2.80-10.23). When COPD patients were excluded from the analysis, the differences persisted between groups. CONCLUSION:In hospitalized CAP patients both hypocapnia and hypercapnia were associated with increased need for ICU admission and higher 30 day mortality. These findings persisted after excluding CAP patients with COPD. Therefore, PaCO2 should be considered for inclusion in future severity stratification criteria to appropriate identified patients that will require higher level of care and are at risk of increased mortality.

PMID: 22677348 [PubMed - as supplied by publisher]