Hypoxaemia in elderly patients suffering from fractured neck of femur*

The purpose of this study was to assess the degree and frequency of hypoxaemia in elderly patients with fractured neck of femur and to note the effect of manipulation and internal fixation on these measurements. Twenty-seven patients aged between 44 and 93 were studied for 5 days after the fracture and for 5 days after surgery. The fractures were treated by internal fixation under either general anaesthesia or spinal analgesia. The arterial oxygen tension following the fracture but before surgery was low relative to the ages of the patients, and the arterial carbon dioxide tension was low in twenty-five out of twenty-seven patients. There was also a significant increase in the dead space/tidal volume ratio (VD/VT) and the alveolar-arterial oxygen tension difference, (A--a)DO2 in eight out of nine patients in the first 5 days following the fracture. The mean arterial oxygen tension was still reduced up to 5 days postoperatively. The VD/VT ratio returned to normal postoperatively although the (A-a)DO2 remained elevated. The haemoglobin and platelet levels following the fracture and before surgery were low, although not remarkably so, and there was no significant change post-operatively. There were no significant changes in the electrocardiograph or the chest radiographs. These results and their implications are discussed.