OBJECTIVE To analyze the risk factors of substandard drug blood concentration of meropenem in patients with hospital acquired pneumonia （HAP）. METHODS Totally 130 HAP patients who were admitted to the intensive care unit of Suzhou Hospital Affiliated to Nanjing Medical University from January 2020 to June 2021 and received steady -state blood concentration test of meropenem were selected as the study subjects . The patient ’s age ，sex，body mass and other medical history were recorded . The steady-state blood trough concentration of meropenem was determined and its target was determined . Univariate and multivariate Logistic regression analysis were used to screen the risk factors for the substandard steady -state blood trough concentration of meropenem. The receiver operating characteristic （ROC）curve was drawn to screen the warning value of the risk factors and evaluate the predictive value of the risk factors . RESULTS The steady -state blood trough concentrations of 85 cases were ≥2 mg/L， and those of 45 cases were ＜2 mg/L. Multivariate Logistic regression analysis showed that age ，negative balance and brain injury were independent risk factors for the substandard steady-state blood trough concentration of meropenem （P＜ 0.05）.ROC curve showed that when the patient was 58 years old，the area under the ROC curve was the largest （0.744）， the sensitivity was 0.882，the specificity was 0.556，and the Youden index was 0.438；when the negative balance was 520.5 mL/24 h，the area under the ROC curve reached the maximum （0.827），the sensitivity was 0.722，the specificity was 0.905，and th e Youden index was 0.628. The creatinine clearance rate in the brain injury group was significantly higher than that in the non -brain injury group ，and the steady -state blood trough concentration of meropenem in the brain injury group was significantly lower than that in the non -brain injury group （P＜0.001）. CONCLUSIONS When the HAP patient ’s age is less than 58 years old ，the brain injury and the negative balance is more than 520.5 mL/24 h，the risk of substandard steady -state blood trough concentration of meropenem will increase .

Objective:To explore the risk factors of linezolid-induced thrombocytopenia (LIT) and evaluate their predictive value.Methods:Medical records of hospital acquired pneumonia (HAP) patients who admitted in Suzhou Municipal Hospital from July 2019 to October 2021 and received linezolid were collected and retrospectively analyzed. Clinical data including general information, comorbidities, linezolid application, laboratory test results, and trough concentration of linezolid was extracted. Patients were divided into LIT group and non-LIT group according to the occurrence of LIT. Clinical characteristics were compared between the 2 groups; risk factors of LIT in patients with HAP were analyzed using a binary logistic regression model, and the odds ratio ( OR) and its 95% confidence interval ( CI) were calculated; the predictive value of the risk factors for LIT were evaluated using receiver operating characteristic (ROC) curve. Results:A total of 74 patients were included in the study, including 55 males and 19 females, aged 82 (73, 88) years. LIT occurred in 25 patients (33.8%). Compared with the non-LIT group, the age and trough concentration of linezolid in patients in the LIT group were higher [88 (81, 92) years vs. 79(70, 86) years, P=0.001; (19.6±10.3) mg/L vs. (9.8±6.4) mg/L, P<0.001], and the baseline platelet count and baseline creatinine clearance rate were lower [181(162, 212) ×10 9/L vs. 229 (169, 289) ×10 9/L, P=0.025; 31(19, 44) ml/(min·1.73 m 2) vs. 46 (27, 65) ml/(min·1.73 m 2), P=0.018]. Binary logistic regression analysis showed that the lower baseline creatinine clearance rate ( OR=0.974, 95 %CI: 0.951-0.998, P=0.035) and higher trough concentration of linezolid ( OR=1.156, 95 %CI: 1.059-1.261, P=0.001) were independent risk factors for LIT in HAP patients. ROC curve analysis showed that the threshold of the age, trough concentration of linezolid, baseline platelet count, and baseline creatinine clearance rate were 87 years (sensitivity 56.0%, specificity 83.7%), 15.4 mg/L (sensitivity 64.0%, specificity 87.8%), 189×10 9/L (sensitivity 67.3%, specificity 68.0%), and 45 ml/(min·1.73 m 2) (sensitivity 53.1%, specificity 80.0%), respectively. Patients were respectively divided into 2 groups according to the thresholds and the incidences of LIT were compared. The results showed that the incidences of LIT in patients with age and trough concentration of linezolid exceeding the thresholds and in patients with baseline plate count and baseline creatinine clearance rate lower than or equal to the thresholds were significantly higher than those in the other patients (all P<0.01). Conclusions:Baseline creatinine clearance rate, trough concentration of linezolid, age, and plate count are risk factors for LIT in HAP patients and their thresholds are 45 ml/(min·1.73 m 2), 15.4 mg/L, 87 years, and 189×10 9/L, respectively. These risk factors have good predictive value for the occurrence of LIT.

Objective:To explore the risk factors of linezolid-induced thrombocytopenia (LIT) and evaluate their predictive value.Methods:Medical records of hospital acquired pneumonia (HAP) patients who admitted in Suzhou Municipal Hospital from July 2019 to October 2021 and received linezolid were collected and retrospectively analyzed. Clinical data including general information, comorbidities, linezolid application, laboratory test results, and trough concentration of linezolid was extracted. Patients were divided into LIT group and non-LIT group according to the occurrence of LIT. Clinical characteristics were compared between the 2 groups; risk factors of LIT in patients with HAP were analyzed using a binary logistic regression model, and the odds ratio ( OR) and its 95% confidence interval ( CI) were calculated; the predictive value of the risk factors for LIT were evaluated using receiver operating characteristic (ROC) curve. Results:A total of 74 patients were included in the study, including 55 males and 19 females, aged 82 (73, 88) years. LIT occurred in 25 patients (33.8%). Compared with the non-LIT group, the age and trough concentration of linezolid in patients in the LIT group were higher [88 (81, 92) years vs. 79(70, 86) years, P=0.001; (19.6±10.3) mg/L vs. (9.8±6.4) mg/L, P<0.001], and the baseline platelet count and baseline creatinine clearance rate were lower [181(162, 212) ×10 9/L vs. 229 (169, 289) ×10 9/L, P=0.025; 31(19, 44) ml/(min·1.73 m 2) vs. 46 (27, 65) ml/(min·1.73 m 2), P=0.018]. Binary logistic regression analysis showed that the lower baseline creatinine clearance rate ( OR=0.974, 95 %CI: 0.951-0.998, P=0.035) and higher trough concentration of linezolid ( OR=1.156, 95 %CI: 1.059-1.261, P=0.001) were independent risk factors for LIT in HAP patients. ROC curve analysis showed that the threshold of the age, trough concentration of linezolid, baseline platelet count, and baseline creatinine clearance rate were 87 years (sensitivity 56.0%, specificity 83.7%), 15.4 mg/L (sensitivity 64.0%, specificity 87.8%), 189×10 9/L (sensitivity 67.3%, specificity 68.0%), and 45 ml/(min·1.73 m 2) (sensitivity 53.1%, specificity 80.0%), respectively. Patients were respectively divided into 2 groups according to the thresholds and the incidences of LIT were compared. The results showed that the incidences of LIT in patients with age and trough concentration of linezolid exceeding the thresholds and in patients with baseline plate count and baseline creatinine clearance rate lower than or equal to the thresholds were significantly higher than those in the other patients (all P<0.01). Conclusions:Baseline creatinine clearance rate, trough concentration of linezolid, age, and plate count are risk factors for LIT in HAP patients and their thresholds are 45 ml/(min·1.73 m 2), 15.4 mg/L, 87 years, and 189×10 9/L, respectively. These risk factors have good predictive value for the occurrence of LIT.