The pressure surrounding the lungs

Although there is present agreement that intrapleural pressure is not uniform throughout the thoracic cavity there is disagreement both as to the magnitude of this difference and as to its significance. A new method has been employed (flow through a Starling resistor) for measuring pleural and esophageal pressure. There appears to be an area in the cephalad thorax, both in the horizontal and vertical head up position, in which end expiratory esophageal and pleural pressure are more negative than in the remainder of the thoracic cavity. The method employed and the possible significance of the findings are discussed.