Risk factors for and predictive nomogram of postoperative hypoxaemia in elderly patients with femoral neck fractures.

OBJECTIVE: To investigate the related risk factors and predictive nomogram of postoperative hypoxaemia in elderly patients with femoral neck fractures. METHODS: This study included patients aged ≥65 years who underwent surgical treatment of acute femoral neck fractures. Univariate and multivariate logistic analyses were performed to determine the incidence of and risk factors for postoperative hypoxaemia. A predictive nomogram was constructed based on the multivariable model. Using the bootstrap method, discrimination was determined by the C-index and calibration plot. RESULTS: The logistic regression analysis showed that the anaesthesia type, surgical procedure, American Society of Anesthesiologists (ASA) classification, preoperative hypoxaemia occurrence, and age were independent predictors of development of postoperative hypoxaemia. The predictive formula for hypoxaemia was established as follows: hypoxaemia=-0.8668×spinal anaesthesia (whether)+0.1162×nerve anaesthesia (whether)+1.9555×plate/screw fixation (whether)+1.4950×hip replacement (whether)+0.4883×ASA classification+1.7153×preoperative oxygenation index+0.1608×age. With the bootstrap method, the prediction curve fit well with the ideal curve, suggesting that the prediction curve constructed in this study has good predictive ability. CONCLUSIONS: Anaesthesia type, surgical procedure, ASA classification, preoperative hypoxaemia occurrence, and age were risk factors for postoperative hypoxaemia in elderly patients with femoral neck fractures. The predictive nomogram was designed for preoperative assessment of the risk of postoperative hypoxaemia by calculating the risk score.

[Establishment of loop-mediated isothermal amplification (LAMP) for detecting Pneumocystis carinii].

Animal model of Pneumocystis carinii pneumonia (PCP) was established for acquiring lung tissue infected with P. carinii. After DNA from rat lungs was extracted, nuclear ribosome small subunit 18s rDNA of P. carinii was amplified by loop-mediated isothermal amplification method at 63 degrees C for 60 min. The product was digested by restriction enzyme Apal I. The results showed that 18s ribosome DNA (rDNA) of P. carinii was cloned into vector pGEX6p2, and the positive clones screened. Therefore, the loop-mediated isothermal amplification has been established for detecting P. carinii.