A 73 y.o. male slipped and fell in the bathtub. He co pain over his back on the L.
What do you see on the CT?
what are you worried about?
Our patient had a posterior rib fracture and no hemothorax on initial CT. The concern is that posterior fractures can lead to complications and in this case the patient died suddenly ten days after the fracture.He was found to have a ruptured descending aorta. Multiple cases of aortic injury have been reported in the literature often with delayed rupture.
COMPLlCATIONS OF RIB FRACTURES
1. Direct injury from the broken ribs. Most commonly, complications of posterior rib fractures lead to pneumothorax or hemothorax. The fractures of the L posterior 4-10 ribs are dangerous because of their close anatomical relationship to the descending thoracic and upper abdominal aorta. The fragments can slowly irritate the aortic wall with breathing or postural changes.
2. Flail chest- is an immediate complication of multiple rib fractures causing a segment of the chest wall to move paradoxically altering respiratory dynamics.
3. Pendelluft-When a flail chest occurs, there is inefficient breathing because air shifts back and for the between different regions of the lung. This is referred to as pendelluft ( from the German for air and pendulum)
An extreme example of pendelluft is found in a spontaneously breathing patient with a sucking chest wound or large flail segment. Air moves back and forth between different parts of the lung instead of entering and leaving the body. This causes decreased oxygenation. During the inspiratory phase, the side without the flail segment expands while the flail segment moves paradoxically out preventing expansion of the lung. These smaller alveoli have increased pressure and in exhalation will shunt carbon dioxide to the normal side creating inefficient respiration.
Pendelluft
RIB FRACTURES IN THE ELDERLY
Rib fractures are common injuries. In healthy patients if there is no hemothorax or pneumothorax they are often treated symptomatically. However, in the geriatric population, they can be more serious. In elderly males, approximately half of these injuries result from ground-level falls or falls from a standing height. Each additional rib fracture in older adults compared to younger patients increases mortality by 19% and the risk of pneumonia by 27%. In the elderly a flail chest requires ICU admission in 82% of cases. In the elderly, rib fractures can also lead to pneumonia, atelectasis and ARDS.
FUN FACT
The Pendelluft effect also occurs in pneumonia and ARDS which makes pressure control difficult since diseased lung will sustain higher pressures. Dr. Ludolph Brauer first described the effect in 1909 when he observed high levels of CO2 during thoracotomies on the side which was uninjured. Research was done in 1956 on respiratory physiology at the University of Rochester because the government was interested in fighter aircraft flying up to 25,000 ft which would require a pressurized cabin. The limits of human tolerance were unknown at that time and they converted a beer tank to a pressure lab for human testing..
beer tank for human pressure testing
https://www.cliniciansbrief.com/article/flail-chest-diagnosis-bandaging
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