Analgesia for the reduction of fractures in children: a comparison of nitrous oxide with intramuscular sedation.

A prospective, randomized study was undertaken to compare the effectiveness of nitrous oxide with intramuscular sedation (meperidine and promethazine) in providing analgesia and amnesia during the reduction and treatment of children's fractures in an outpatient clinic setting. Fifteen patients received a 50:50 mixture of nitrous oxide and oxygen, and 15 received intramuscular injection. The two groups were similar in regard to gender distribution, age, and fracture types. Pain response was recorded using the Children's Hospital of Eastern Ontario (Canada) Pain Scale (CHEOPS) at the time of fracture reduction and 30 min postreduction. At the first follow-up visit a questionnaire regarding the patient's memory and subjective experience of the fracture reduction was answered. Data between the two groups were compared using the Mann-Whitney test. The CHEOPS scores, and the memory and subjective experience of the fracture reduction were similar between the two groups. Time in the outpatient department averaged 83 min for the intramuscular group and 30 min for the nitrous oxide group (p < 0.01). All of the nitrous oxide patients stated they would use nitrous oxide again, whereas only eight of 15 intramuscular patients stated they would try intramuscular sedation again. Nitrous oxide is as effective as intramuscular sedation in providing analgesia and amnesia in the treatment of children's fractures while having a more rapid onset and a shorter recovery period with greater patient acceptance.

Correlation of mechanical properties of vertebral trabecular bone with equivalent mineral density as measured by computed tomography.

We tried to determine whether mineral-equivalent measurements that were obtained using computed tomography could be used to predict the mechanical properties of vertebral trabecular bone. Vertebral bodies that had been obtained during routine autopsy were evaluated by computed tomography. The mechanical properties of the vertebral trabecular bone were determined by subjecting cylindrical specimens to simple compression until failure occurred. The ultimate strength and elastic modulus were determined from load time curves, using constant displacement rate loading. Atomic absorption spectrophotometry was used to determine the weight per cent calcium of each specimen, and quantitative light microscopy was used to determine area fraction bone. Significant positive correlations were found between the observed mechanical properties of the trabecular bone and the equivalent mineral density as measured by computed tomography. Compressive strength (r = 0.720), elastic modulus (r = 0.574), trabecular calcium density (r = 0.780), and area fraction bone (r = 0.579) were all correlated with the equivalent mineral density.