Mechanism
Although the mechanism is unknown, it is proposed that a blow to the abdomen may raise the pressure within the abdomen so high that the diaphragm ruptures. Blunt trauma creates a large pressure gradient between the abdominal and thoracic cavities; this gradient, in addition to causing the rupture, can also cause abdominal contents to herniate into the thoracic cavity. Abdominal contents in the pleural space interfere with heart function and lung function. High intrathoracic pressure results in an increase in right atrial pressure, disrupting the filling of the heart and venous return of blood. As venous return determines cardiac output, this results in a reduction of cardiac output. If ventilation of the lung on the side of the tear is severely inhibited, hypoxemia (low blood oxygen) results. Usually, the rupture is on the same side as an impact. A blow to the side is three times more likely to cause diaphragmatic rupture than a blow to the front. Diagnosis
Physical examinations are not accurate, as there is usually no specific physical sign that can be used to diagnose this condition. Thoracoscopic and laparoscopic methods can be accurate. Chest X-ray is known to be unreliable in diagnosing diaphragmatic rupture; it has low sensitivity and specificity for the injury. Often another injury such as pulmonary contusion masks the injury on the X-ray film. Half the time, initial X-rays are normal; in most of those that are not, hemothorax or pneumothorax is present.
Verteporfin (trade name Visudyne), a benzoporphyrin derivative, is a medication used as a photosensitizer for photodynamic therapy to eliminate the abnormal blood vessels in the eye associated with conditions such as the wet form of macular degeneration. Verteporfin accumulates in these abnormal blood vessels and, when stimulated by nonthermal red light with a wavelength of 689 nm in the presence of oxygen, produces highly reactive short-lived singlet oxygen and other reactive oxygen radicals, resulting in local damage to the endothelium and blockage of the vessels.Verteporfin is also used off-label for the treatment of central serous retinopathy. Administration
Verteporfin is usually injected intravenously into the largest arm vein. It is injected at a dose of 6 mg/m2 and light-activated. It is usually is given 15 minutes before laser treatment. This dose can be repeated 4 times per year. Contraindications
Porphyria. Side effects
Most common side effects are blurred vision, headache, and local effects at the injection site. Also, photosensitivity; it is strictly advised to avoid exposure to sunlight and unscreened lighting until 48 hours after verteporfin administration.Dogs and rats have been treated with inactivated daily doses 32–70 times higher than the dose advised for humans. The 4 weeks of treatment resulted in mild extravascular hemolysis and hematopoiesis in the animals. Interactions
Verteporfin is known to interact with the herbal remedy feverfew (Tanacetum parthenium), the latter of which seems to act as an antagonist to verteporfin for unknown reasons.