Voluntary apnea can be achieved by closing the vocal cords, simultaneously keeping the mouth closed and blocking the nasal vestibule, or constantly activating expiratory muscles, not allowing any inspiration. Complications
Under normal conditions, humans cannot store much oxygen in the body. Prolonged apnea leads to severe lack of oxygen in the blood circulation, leading to dysfunction of organ systems. Permanent brain damage can occur after as little as three minutes and death will inevitably ensue after a few more minutes unless ventilation is restored. However, under special circumstances such as hypothermia, hyperbaric oxygenation, apneic oxygenation (see below), or extracorporeal membrane oxygenation, much longer periods of apnea may be tolerated without severe detrimental consequences. Untrained humans usually cannot sustain voluntary apnea for more than one or two minutes, since the urge to breathe becomes unbearable. The reason for the time limit of voluntary apnea is that the rate of breathing and the volume of each breath are tightly regulated to maintain constant values of CO2 tension and pH of the blood more than oxygen levels. In apnea, CO2 is not removed through the lungs and accumulates in the blood. The consequent rise in CO2 tension and drop in pH result in stimulation of the respiratory centre in the brain which eventually cannot be overcome voluntarily. The accumulation of carbon dioxide in the lungs will eventually irritate and trigger impulses from the respiratory center part of the brain and the phrenic nerve. Rising levels of carbon dioxide signal the body to breathe and resume unconscious respiration forcibly.
These entities must be clinically excluded. Clinical condition characterized by ovarian mass, ascites, and right-sided pleural effusion. Ovarian malignancy and the other causes of pelvic mass, ascites, and pleural effusion to be considered, History of early satiety, weight loss with increased abdominal girth, bloating, intermittent abdominal pain, dyspnea, nonproductive cough may help in differentiating potential local factor causing such symptoms. Treatment
Treatment of Meigs syndrome consists of thoracentesis and paracentesis to drain off the excess fluid (exudate), and unilateral salpingo-oophorectomy or wedge resection to correct the underlying cause. Eponym
Meigs syndrome is named for Joe Vincent Meigs. References


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