Subject(s)
Obesity Hypoventilation Syndrome/diagnosis , Obesity Hypoventilation Syndrome/physiopathology , Acidosis, Respiratory/diagnosis , Acidosis, Respiratory/physiopathology , Blood Gas Analysis , Humans , Hypercapnia/diagnosis , Hypercapnia/physiopathology , Male , Middle Aged , Obesity, Morbid/complicationsSubject(s)
Plethysmography, Whole Body/methods , Pulmonary Disease, Chronic Obstructive/physiopathology , Breath Tests/methods , Forced Expiratory Volume , Humans , Lung Volume Measurements/methods , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/diagnosis , Total Lung Capacity , Vital CapacityABSTRACT
Excess ventilation during exercise with accompanying dyspnea is characteristic of chronic heart failure (CHF), and these patients often exhibit increased Ve relative to the Vco(2) compared with normal subjects. This can be measured in several ways, including using such variables as the slope of Ve versus Vco(2), the lowest ratio of Ve/Vco(2), and the ratio of Ve/Vco(2) at the lactic acidosis threshold or peak exercise. There is now considerable evidence that the degree of excess ventilation during exercise in patients with CHF is a robust predictor of outcome and identifies higher-risk patients requiring aggressive treatment, including heart transplantation. The mechanism of excess ventilation in patients with CHF during exercise is not completely understood. It may be related to enhanced output of chemoreceptors or peripheral muscle ergoreceptors, increased dead space/Vt ratio due to increased contribution of high ventilation-perfusion lung regions or rapid shallow breathing caused by earlier onset of lactic acidosis, or likely resulting from a combination of these causes.
Subject(s)
Exercise Test/methods , Exercise , Heart Failure/diagnosis , Pulmonary Ventilation , Acidosis, Respiratory/complications , Acidosis, Respiratory/diagnosis , Acidosis, Respiratory/physiopathology , Blood Gas Analysis , Carbon Dioxide/metabolism , Chronic Disease , Exercise Tolerance , Heart Failure/complications , Heart Failure/physiopathology , Humans , Oxygen Consumption , Predictive Value of Tests , Prognosis , Respiratory Dead SpaceSubject(s)
Critical Illness , Respiratory Dead Space , Respiratory Distress Syndrome/diagnosis , Blood Gas Analysis , Critical Care/methods , Humans , Intensive Care Units , Predictive Value of Tests , Pulmonary Gas Exchange , Respiration, Artificial/methods , Respiratory Distress Syndrome/therapy , Tidal VolumeABSTRACT
A wide array of diagnoses must be considered when a patient with advanced liver disease and human immunodeficiency virus (HIV) infection presents with hypoxemia. It is important to entertain the possibility of hepatopulmonary syndrome (HPS) in such patients, a diagnosis that must be confirmed with a contrast-enhanced echocardiogram (bubble study). We describe a case of HPS diagnosed in a patient with HIV infection and chronic liver disease and review the literature on HPS.
