Non-Answered Questions in Patients with Endobronchial Valve Placement for Lung Volume Reduction.

Endoscopic lung volume reduction is a minimally invasive procedure performed to reduce the space occupied by the emphysemas' lobes. This procedure has been demonstrated to be beneficial for patients with advanced chronic obstructive pulmonary disease and severe hyperinflation. The use of endobronchial valves is increasing, as well as the number of reports of adverse events. The most common complications after the procedure are a pneumothorax, bleeding, infections, the need for valve removal, and valve expulsion. We have recently treated a patient who achieved immediate left upper lobe atelectasis but developed a pneumothorax on the 6th day and near-fatal kinking of the left lower lobe bronchus. This patient had asphyctic episodes probably due to a functional left pneumonectomy. We should consider this unusual complication in patients undergoing endoscopic lung volume reduction whose condition worsens after achieving complete lobar atelectasis.

Ventilatory inefficiency as a limiting factor for exercise in patients with COPD.

BACKGROUND: Ventilatory inefficiency increases ventilatory demand; corresponds to an abnormal increase in the ratio of minute ventilation (V_dot(E)) to CO(2) production (V_dot(CO(2))); represents increased dead space, deregulation of respiratory control, and early lactic threshold; and is associated with expiratory flow limitation that enhances dynamic hyperinflation and may limit exercise capacity. OBJECTIVE: To evaluate the influence of ventilatory inefficiency over exercise capacity in COPD patients. METHODS: Prospective study of 35 COPD subjects with different levels of severity, in whom cardiopulmonary stress test was performed. Ventilatory inefficiency was represented by the V_dot(E) /V_dot(CO(2)) relation. Its influence over maximal oxygen consumption (V_dot(O(2))max), power (W), and ventilatory threshold was evaluated. Surrogate parameters of cardiac function, like oxygen pulse (V_dot(O(2))/heart rate) and circulatory power (%V_dot(O(2))max × peak systolic pressure), were also evaluated. RESULTS: Cardiopulmonary stress test was stopped due to dyspnea with elevated V_dot(E) and marked reduction of breathing reserve. A severe increase in V_dot(CO(2)) (mean ± SD 35.9 ± 5.6), a decrease of V_dot(O(2)) (mean ± SD 75.2 ± 20%), and a decrease of W (mean ± SD 68.6 ± 23.3%) were demonstrated. Twenty-eight patients presented dynamic hyperinflation. Linear regression showed a reduction of 2.04% on V_dot(O(2>))max (P < .001), 2.6% on W (P < .001), 1% on V_dot(O(2))/heart rate (P = .049), and 322.7 units on circulatory power (P = .02) per each unit of increment in V_dot(E)/V_dot(CO(2)), respectively. CONCLUSIONS: Ventilatory inefficiency correlates with a reduction in exercise capacity in COPD patients. Including this parameter in the evaluation of exercise limitation in this patient population may mean a contribution toward the understanding of its pathophysiology.

Nasolaryngoscopic validation of a set of clinical predictors of aspiration in a critical care setting.

BACKGROUND: Aspiration is frequent in patients with acute neurologic disorders and swallowing dysfunction. Its incidence in stroke, as high as 51%, increases mortality by up to 3 times. Pneumonia, its main complication, further increases morbidity, mortality, and patient care costs. The objective of this study was to evaluate a set of bedside predictors of aspiration ["wet voice," 3-oz water swallow test, and cervical auscultation in an intensive care unit (ICU)] and compare them with nasolaryngoscopy as the gold standard. METHODS: We conducted a prospective, nonblinded study of bedside predictors of aspiration risks in 65 consecutive ICU patients with an acute neurologic disorder or a severe medical or surgical condition with decreased level of consciousness. RESULTS: Endoscopic aspiration was detected in 17 patients. Sensitivities for wet voice, 3-oz water swallow test, and cervical auscultation were 58.82%, 88.23%, and 82.35%; specificities were 78.26%, 62.50%, and 80.43%. Positive predictive values were 50%, 45.45%, and 60.86%, and negative predictive values were 83.72%, 93.75%, and 92.50%, respectively. Positive likelihood ratios were 2.70, 2.35, and 4.20, respectively. The association of 2 positive clinical predictors, wet voice and cervical auscultation or wet voice and 3-oz water swallow test, improved specificity to 92.85% and 84.61%, positive predictive values to 83.33% and 69.23%, and likelihood ratios to 10.76 and 5.85, respectively. CONCLUSIONS: Bedside clinical predictors for aspiration risks are a useful screening tool for ICU patients presenting with risk factors for this complication.