[A retrospective cohort study based on propensity score matching evaluated the effect of bronchoalveolar lavage on the clinical prognosis of children with macrolide drug-resistant Mycoplasma pneumoniae pneumonia].

To evaluate the effect of bronchoalveolar lavage (BAL) on the clinical prognosis of children with macrolide drug-resistant Mycoplasma pneumoniae pneumonia (MRMPP) in a retrospective cohort study based on propensity score matching (PSM).A retrospective cohort study based on propensity score matching retrospectively collected the clinical data of hospitalized patients diagnosed with mycoplasma macrolide drug-resistant pneumonia (MRMPP) in Respiratory Department of Hunan Children's Hospital from January 2020 to August 2023. According to whether bronchoalveolar lavage (BAL) was performed during hospitalization, the children were divided into BAL group and non-BAL group, and the baseline information of the two groups was matched by propensity scores, and the clinical prognosis was compared. A total of 302 children were screened, and 150 cases were successfully matched, including 59 cases in the BAL group and 91 cases in the non-BAL group. The results showed that the differences between the non-BAL group and the BAL group before PSM(<i>P</i><0.05) were significantly different in age [(4.60±2.97)years <i>vs</i> (5.41±3.02) years, <i>t</i>=-2.273, <i>P</i>=0.024], shortness of breath (9.4% <i>vs</i> 22.5%, <i>χ²</i>=9.864, <i>P</i>=0.002), and radiographic manifestations [lung interstitial changes (29.8% <i>vs</i> 15.3%, <i>χ²</i>=8.009, <i>P</i>=0.005), lung consolidation (17.3% <i>vs</i> 55.9%, <i>χ²</i>=48.457, <i>P</i><0.001), spotted flaky infiltrates (52.4% <i>vs</i> 27.9%, <i>χ²</i>=17.056, <i>P</i><0.001)], bacterial infection (3.2% <i>vs</i> 9.2%, <i>χ²</i>=4.845, <i>P</i>=0.028), duration of azithromycin or doxycycline use [4(2, 5) days <i>vs</i> 5(3, 6) days, <i>Z</i>=-2.374, <i>P</i>=0.018], White Blood Cell Count at admission [7.94 (6.25, 10.34)×10⁹/L <i>vs</i> 7.21 (5.65, 9.01)×10⁹/L, <i>Z</i>=-2.445, <i>P</i>=0.014], D Dimer [0.58 (0.44, 0.83) μg/ml <i>vs</i> 0.80 (0.52, 1.12) μg/ml, <i>Z</i>=-3.154, <i>P</i>=0.002], but there was no significant difference between the two groups in the above indexes after PSM (<i>P</i>>0.05). The duration of hospitalization, cough relief, disappearance of rales and fever in the BAL group was shortened in the BAL group compared with that in the non-BAL group [5 (4, 7) days <i>vs</i> 7 (5, 8) days, <i>Z</i>=-2.373, <i>P</i>=0.018], and the difference was statistically significant (<i>P</i><0.05). Linear regression analysis of PSM cohort study showed that BAL was negatively correlated with fever time (β=-4.369, 95%<i>CI</i>:-8.600--0.138, <i>P</i><0.05). In conclusion, BAL can shorten the fever time of MRMPP, and early BAL in addition to conventional treatment has a positive effect on the prognosis of children.