Peripartum pleural effusion

Functional similarities between pleura and the renal proximal tubule – membrane and cellular considerations

The small amount of liquid that, under physiological conditions, is presented in the pleural cavity has been the focus of extensive research for more than a century. However, there are still unanswered questions and considerable controversies about the nature of the forces governing its movement into and out of the pleural cavity. Early in the 20th century has been proposed that pleural fluid turnover is simple based on the balance between hydraulic and colloid osmotic pressures existing across the pleural membranes. This original hypothesis has not been validated by data accumulating over the last 20 years. Pleural tissues and renal proximal tubules present high water permeability, small transepithelial electrical resistance (22.02 Omega cm2) and the same cation transportation such as Na+ channels, Na+-K+ ATPase channels, and Na+-H+ exchanger. In contrast to previous conflicting theories concerning pleura fluid movement, the same functional characteristics suggest the hypothesis that physiology of pleura is similar to proximal tubules.

Cardiac disease and pregnancy

The pregnant state imposes a supraphysiologic strain on the pregnant woman's cardiac performance through complex biochemical, electric, and physiologic changes affecting the blood volume, myocardial contractility, and resistance of the vascular bed. In the presence of underlying heart disease, these changes can compromise the woman's hemodynamic balance, her life, and that of her unborn child. Cardiac pathology represents a heterogeneous group of disorders, each with its own hemodynamic, genetic, obstetric, and social implications. Physicians caring for these women should actively address the issue of reproduction. Ideally, pregnancy should be planned to occur after optimization of cardiac performance by medical or surgical means. Once pregnancy is achieved, the concerted effort of a multidisciplinary team of obstetricians, cardiologists, anesthesiologists, nursing, social, and other services provides the best opportunity to carry the pregnancy to a successful outcome.