PK/PD study of tigecycline in severely infected patients with continuous renal replacement therapy.

OBJECTIVE: The aim of this study was to analyze the pharmacokinetics/pharmacodynamics (PK/PD) of higher-dose tigecycline (100 mg q12h) in severely infected intensive care unit (ICU) patients receiving continuous renal replacement therapy (CRRT). MATERIALS AND METHODS: In this prospective single-center observational study, severely infected patients receiving intravenous tigecycline were enrolled. They were divided into a CRRT group (7 cases) and a non-CRRT group (9 cases). The blood samples and CRRT ultrafiltrate were collected. The drug concentration in each sample was determined by a HPLC-UV method. The pharmacokinetic parameters were simulated and calculated with DAS 2.0. The PK/PD parameters were evaluated according to published data. The registration number of this study is NCT02931526 in ClinicalTrials.gov. RESULTS: In the non-CRRT group, Cmax, Cmin, and AUC0-24 were 1.00 ± 0.66 µg×mL-1, 0.20 ± 0.12 µg×mL-1, and 22.12 ± 14.46 µg×h×mL-1, respectively. The clinical efficiency was 55.6%, and the bacterial clearance rate was 77.8%. In the CRRT group, Cmax, Cmin, and AUC0-24 were 0.96 ± 0.31 µg×mL-1, 0.22 ± 0.12 µg×mL-1, and 19.90 ± 8.14 µg×h×mL-1, respectively. The clinical efficiency was 28.6%, and the bacterial clearance rate was 28.6%. The individual differences of tigecycline plasma concentrations in our study were widely variable, and the differences of the two groups' PK/PD parameters had no statistical significance (p < 0.05). CONCLUSION: CRRT may have had little influence in tigecycline metabolism in our study, and therapeutic drug monitoring needs to be introduced for critically ill patients because of various pharmacokinetic parameters.

Continuous positive airway pressure improves respiratory mechanics and efficiency of neural drive in stable COPD: an exploratory study.

BACKGROUND: Continuous positive airway pressure (CPAP) is a major treatment strategy for severe chronic obstructive pulmonary disease (COPD), especially with respiratory failure. However, it remains inconclusive whether CPAP affects respiratory mechanics and neural drive in stable COPD patients without respiratory failure. METHODS: Twenty-two COPD patients without respiratory failure received CPAP starting from 4 to 10 cmH2O in 1 cmH2O increments. Respiratory pattern, end expiatory lung volume (EELV), dynamic PEEPi (PEEPidyn), airway resistance (Raw), pressure-time product of diaphragmatic pressure (PTPdi) and esophageal pressure (PTPeso), root mean square (RMS) of diaphragm electromyogram (EMGdi) and ratio of ventilation (Ve) to EMGdi (i.e., Ve/RMS) were measured before and at each level of continue positive airway pressure (CPAP). A subgroup analysis was performed between patients with and without inspiratory muscle weakness. RESULTS: Nineteen patients completed the treatment. The respiratory pattern improved significantly after CPAP. Raw, PTPdi, and Pdi decreased significantly. ΔEELV decreased at 4 cmH2O (P<0.05), but increased significantly at >8 cmH2O. PEEPidyn decreased from 2.18±0.98 to 1.37±0.55 cmH2O. RMS increased while Ve/RMS improved significantly after CPAP (P<0.05). Besides, CPAP could significantly improve respiratory mechanics in patients with inspiratory muscle weakness. CONCLUSIONS: CPAP improves respiratory pattern, PEEPi, Raw, work of breathing and efficiency of neural drive in COPD patients without respiratory failure, but easily increases dynamic pulmonary hyperinflation. These effects on respiratory mechanics are significant in patients with inspiratory muscle weakness.

Procalcitonin levels in patients with positive blood culture, positive body fluid culture, sepsis, and severe sepsis: a cross-sectional study.

BACKGROUND: Numerous investigations on procalcitonin (PCT) have been carried out, although few with large sample size. To deal with the complexity of sepsis, an understanding of PCT in heterogeneous clinical conditions is required. METHODS: Hospitalized patients aged 10-79 years were included in this retrospective and cross-sectional study. PCT tests were assayed within 2 days of blood culture. RESULTS: A total of 2952 cases (from 2538 patients) were enrolled in this study, including 440 cases in the 'positive BC' group, 123 cases in the 'positive body fluid culture' group, and 2389 cases in the 'negative all culture' group. Median PCT values were 4.53 ng/ml, 2.95 ng/ml, and 0.49 ng/ml, respectively. Median PCT values in the gram-negative BC group and gram-positive BC group, respectively, were 6.99 ng/ml and 2.96 ng/ml. Median PCT values in the 'positive hydrothorax culture' group, 'positive ascites culture' group, 'positive bile culture' group, and 'positive cerebrospinal fluid culture' group, respectively, were 1.39 ng/ml, 8.32 ng/ml, 5.98 ng/ml, and 0.46 ng/ml. In all, 357 cases were classified into the 'sepsis' group, 150 of them were classified into the 'severe sepsis' group. Median PCT values were 5.63 ng/ml and 11.06 ng/ml, respectively. CONCLUSIONS: PCT could be used in clinical algorithms to diagnose positive infections and sepsis. Different PCT levels could be related to different kinds of microbemia, different infection sites, and differing severity of sepsis.

[Intensive hemoperfusion and long-term hemofiltration for treatment of paraquat poisoning: a case report].

OBJECTIVE: A 20-year-old male patient was admitted in our department 14 h after paraquat poisoning at the dose of about 50 mL. The patient underwent intensive hemoperfusion for 2 h (3 times a day) for 9 consecutive days and received continuous renal replacement therapy (CRRT) in the mode of continuous veno-venous hemofiltration (CVVH) for 10 consecutive days in addition to routine medications. The biochemical indexes were monitored during the therapy. After the treatment, paraquat concentrations in the blood and urine were decreased, and the patient's urine volume (UV) increased, serum creatinine (Cr) level decreased, and the oxygenation index became normal. Dynamic CT scan showed no obvious pulmonary fibrosis. The patient was followed up for 6 months after discharge and no complaint of discomforts was reported. This case suggests that early intensive hemoperfusion and long-term CVVH may help improve the prognosis after paraquat poisoning.