[Assessment of risk factors for bronchopulmonary dysplasia with pulmonary hypertension and construction of a prediction nomogram model].

Objective: To explore the risk factors of pulmonary hypertension (PH) in premature infants with bronchopulmonary dysplasia (BPD), and to establish a prediction model for early PH. Methods: This was a retrospective cohort study. Data of 777 BPD preterm infants with the gestational age of <32 weeks were collected from 7 collaborative units of the Su Xinyun Neonatal Perinatal Collaboration Network platform in Jiangsu Province from January 2019 to December 2022. The subjects were randomly divided into a training cohort and a validation cohort at a ratio of 8∶2 by computer, and non-parametric test or χ2 test was used to examine the differences between the two retrospective cohorts. Univariate Logistic regression and multivariate logistic regression analyses were used in the training cohort to screen the risk factors affecting the PH associated with BPD. A nomogram model was constructed based on the severity of BPD and its risk factors,which was internally validated by the Bootstrap method. Finally, the differential, calibration and clinical applicability of the prediction model were evaluated using the training and verification queues. Results: A total of 130 among the 777 preterm infants with BPD had PH, with an incidence of 16.7%, and the gestational age was 28.7 (27.7, 30.0) weeks, including 454 males (58.4%) and 323 females (41.6%). There were 622 preterm infants in the training cohort, including 105 preterm infants in the PH group. A total of 155 patients were enrolled in the verification cohort, including 25 patients in the PH group. Multivariate Logistic regression analysis revealed that low 5 min Apgar score (OR=0.87, 95%CI 0.76-0.99), cesarean section (OR=1.97, 95%CI 1.13-3.43), small for gestational age (OR=9.30, 95%CI 4.30-20.13), hemodynamically significant patent ductus arteriosus (hsPDA) (OR=4.49, 95%CI 2.58-7.80), late-onset sepsis (LOS) (OR=3.52, 95%CI 1.94-6.38), and ventilator-associated pneumonia (VAP) (OR=8.67, 95%CI 3.98-18.91) were all independent risk factors for PH (all P<0.05). The independent risk factors and the severity of BPD were combined to construct a nomogram map model. The area under the receiver operating characteristic (ROC) curve of the nomogram model in the training cohort and the validation cohort were 0.83 (95%CI 0.79-0.88) and 0.87 (95%CI 0.79-0.95), respectively, and the calibration curve was close to the ideal diagonal. Conclusions: Risk of PH with BPD increases in preterm infants with low 5 minute Apgar score, cesarean section, small for gestational age, hamodynamically significant patent ductus arteriosus, late-onset sepsis, and ventilator-associated pneumonia. This nomogram model serves as a useful tool for predicting the risk of PH with BPD in premature infants, which may facilitate individualized early intervention.

Pentraxin 3 in the assessment of ventilator-associated pneumonia: an early marker of severity.

OBJECTIVES: The aim was to assess the diagnostic and prognostic value of measuring pentraxin 3 (PTX3) together with C-reactive protein (CRP) in patients with ventilator-associated pneumonia (VAP). BACKGROUND: The PTX3 values increase rapidly during multiple inflammatory conditions, but little is known about its characteristics in VAP. METHODS: Measurement of PTX3 and CRP levels in plasma from 136 consecutive patients receiving mechanical ventilation > 48 h in a prospective single center study. RESULTS: A PTX3 threshold of >16.43 ng/ml provided a specificity of 74.0% and a sensitivity of 68.6% for the diagnosis of VAP. PTX3 correlated with severity of sepsis and peaked earlier than CRP in patients with confirmed VAP. Multivariate Cox regression analysis showed PTX3 was the independent predictor for mortality of VAP. CONCLUSIONS: PTX3 was not superior to CRP as a biomarker to diagnose VAP, but it was an early indicator of inflammation and had better prognostic value to predict mortality than CRP.

Assessment of a training programme for the prevention of ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia (VAP) is the most frequent nosocomial infection in intensive care units (ICUs). Most published studies have analysed nurses' theoretical knowledge about a specific procedure; however, the transfer of this knowledge to the practice has received little attention. AIM: To assess the impact of training session on nurses' knowledge regarding VAP, compliance with VAP preventive measures, VAP incidence and determining whether nursing workload affects compliance. METHOD: A prospective, quasiexperimental, pre- and post-study of the nursing team in a 16-bed medical/surgical ICU. Pre-intervention phase: a questionnaire to assess nurses' knowledge of VAP prevention measures, direct observation and review of clinical records to assess compliance. Intervention phase: eight training sessions for nurses. The post-intervention phase mirrored the pre-intervention phase. FINDINGS: Nurses answered more questions correctly on the post-intervention questionnaire than on the pre-intervention (17·87 ± 2·69 versus 15·91 ± 2·68, p = 0·002). Compliance with the following measures was better during the post-intervention period (p = 0·001): use of the smallest possible nasogastric tube, controlled aspiration of subglottic secretions and endotracheal tube cuff pressure, use of oral chlorhexidine and recording the endotracheal tube fixation number. VAP incidence remained unchanged throughout the study. However, a trend towards lower incidence of late (>4 days after intubation) VAP was observed (4·6 versus 3·1 episodes/1000 ventilation days, p = 0·37). CONCLUSION: The programme improved both knowledge of and compliance with VAP preventive measures, although improved knowledge did not always result in improved compliance.

Soluble urokinase plasminogen activator receptor (suPAR) for assessment of disease severity in ventilator-associated pneumonia and sepsis.

Urokinase plasminogen activator (uPAR) is a receptor mainly expressed on peripheral blood mononuclear cells and neutrophils. The role of its soluble form, namely suPAR, as a predictor of sepsis outcome in a homogenous cohort of 180 septic patients, was investigated. Blood from 180 patients with ventilator-associated pneumonia (VAP) and sepsis was collected for seven consecutive days. suPAR and PCT were measured in serum by an enzyme immunoassay and an immuno-time-resolved amplified cryptate assay respectively. Neutrophils and monocytes were isolated on day 1 and incubated. suPAR levels greater than 10.5 ng/ml had 80% specificity and 77.6% positive predictive value to discriminate between severe sepsis and sepsis. suPAR levels greater than 12.9 ng/ml had 80% specificity and 76.1% positive predictive value for prognosis of unfavorable outcome. suPAR levels were significantly lower among survivors than among non-survivors over follow-up. Step-wise Cox regression analysis found suPAR as an independent factor related with unfavorable outcome (p: 0.026). Concentrations of suPAR in supernatants of neutrophils of patients with sepsis were greater compared to controls. It is concluded that suPAR is a reliable marker of sepsis severity and a strong independent predictor of unfavorable outcome in VAP and sepsis. Neutrophils are involved in release.

Length of stay and hospital costs associated with a pharmacodynamic-based clinical pathway for empiric antibiotic choice for ventilator-associated pneumonia.

STUDY OBJECTIVE: To determine hospital costs associated with the use of a clinical pathway implemented in our intensive care units (ICUs) to optimize antibiotic regimen selection for patients with ventilator-associated pneumonia (VAP) compared with costs in a historical control group treated according to prescriber preference. DESIGN: Retrospective cost analysis from the hospital perspective. SETTING: Single, tertiary-care medical center. PATIENTS: One hundred sixty-six adults with VAP from the medical, surgical, and neurotrauma ICUs (73 historical control patients [2004-2005] and 93 patients given an empiric antibiotic clinical pathway for VAP [2006-2007]). MEASUREMENTS AND MAIN RESULTS: The VAP clinical pathway consisted of an ICU-specific three-drug regimen that considered local minimum inhibitory concentration distributions and a pharmacodynamically optimized dosing strategy. Hospital cost data were collected and inflated to 2007 according to the consumer price index. The VAP-related length of treatment, hospitalization costs, and antibiotic costs were compared between groups. The median VAP length of treatment was 24 days (interquartile range [IQR] 13-35 days] and 11 days (IQR 7-17 days) for historical and clinical pathway groups, respectively (p<0.001). Daily hospital costs were similar for both cohorts over the first 7 days, after which costs declined significantly for patients treated with the clinical pathway (p<0.001). When controlling for baseline differences between groups and length of stay before development of VAP, patients treated with the clinical pathway had shorter lengths of ICU stay after VAP, shorter total hospital lengths of stay after VAP, and lower hospital costs after the treatment of VAP. Median total antibiotic costs for individual patients were similar between groups ($535 [IQR $261-998] vs $482 [IQR $222-985] clinical pathway vs control, p=0.45), and the proportion of VAP hospital resources consumed by antibiotics for both groups was low. CONCLUSION: Although aggressive dosing of more costly antibiotics was empirically prescribed using the clinical pathway, patients in this group exhibited a shorter duration of treatment, reduced hospital length of stay after VAP, and lower hospital costs without any significant increase in antibiotic expenditures.

Pharmacodynamic-based clinical pathway for empiric antibiotic choice in patients with ventilator-associated pneumonia.

BACKGROUND: Because of the high frequency of multidrug resistant bacteria in our intensive care units (ICUs), we implemented a ventilator-associated pneumonia (VAP) clinical pathway based on unit-specific minimum inhibitory concentration (MIC) distributions and pharmacodynamic modeling in 3 of our ICUs. METHODS: This was a prospective, observational evaluation with a historical control group in adult patients (n = 168) who met clinical and radiologic criteria for VAP. Monte Carlo simulation was used to determine antibiotic regimens having the greatest likelihood of achieving bactericidal exposures against Pseudomonas aeruginosa. Antibiotic regimens were incorporated into an ICU-specific computerized clinical pathway as empiric agents of choice. RESULTS: Pharmacodynamic modeling found 3-hour infusions of cefepime 2 g every 8 hours or meropenem 2 g every 8 hours plus tobramycin and vancomycin would provide the greatest probability of empirically treating VAP in these ICUs. Infection-related mortality was reduced by 69% (8.5% vs 21.6%; P = .029), infection-related length of stay was shorter (11.7 +/- 8.1 vs 26.1 +/- 18.5; P < .001), and fewer superinfections were observed in patients treated on the pathway. A number of patients with nonsusceptible P aeruginosa were successfully treated with high-dose, 3-hour infusion regimens. CONCLUSIONS: In our ICUs where multidrug resistant bacteria are common, an approach considering ICU-specific antibiotic MICs coupled with pharmacodynamic dosing strategies resulted in improved outcomes and shorter duration of treatments.