Early prediction of treatment failure in severe community-acquired pneumonia: The PRoFeSs score

Derivation and validation of a model to predict treatment failure among under five children with severe community acquired pneumonia who are admitted at Debre Tabor specialized comprehensive hospital

BACKGROUND

Severe community-acquired pneumonia related treatment failure is persistence of features of severe pneumonia after initiation of antimicrobial therapy or a worsening clinical condition within 48-72 hours of the commencement of the antibiotics. Even though it is the most devastating public health problem in Ethiopia, there is no study to derivate and validate a model to predict treatment failure. To do this, nomogram was used to estimate the probability of treatment failure for each individual child and to classify their risk of treatment failure.

OBJECTIVE

to develop and validate the model to predict treatment failure among under five children with severe community-acquired pneumonia in Debre Tabor comprehensive specialized hospital.

METHOD

A secondary analysis of the previously collected prospective follow-up study was used for further analysis among 590 under-5 children hospitalized with severe community-acquired pneumonia. The STATA version 17 software was used for analysis. Descriptive analysis was summarized by frequency and percentage. A multivariable binary logistic regression was also conducted, and the model performance was evaluated using the receiver operating characteristics curve with its area under the curve and calibration curve. Internal validation of the model was assessed using the bootstrap technique. The decision curve analysis was also used to evaluate the usefulness of the nomogram.

RESULTS

The incidence of treatment failure among severe community-acquired pneumonia children was 28.1% (95% CI: 24.7%-30.8%). The previous history of severe community-acquired pneumonia, abnormal pulse rate, chest indrowing, anemia, HIV status, and plural effusion remained for the final model. The area under the curve for the original model and validated model was 0.7719 (95%CI: 0.729, 0.815) and 0.7714 (95% CI: 0.728-0.82), respectively. The decision curve analysis showed that the nomogram had a better net benefit across the threshold probability.

CONCLUSION

The incidence of treatment failure among children with severe community-acquired pneumonia was high in Debre Tabor comprehensive hospital. The previous history of severe community-acquired pneumonia, abnormal pulse rate, chest indrowing, anemia, HIV status, and plural effusion were the significant factors to develop the predictive model. The model had good discriminatory performance and internally valid. Similarly, the model has a good calibration ability with an insignificant loss of accuracy from the original. The models can have the potential to improve treatment outcomes in the clinical settings. But needs external validation before use.

Signatures of lower respiratory tract microbiome in children with severe community-acquired pneumonia using shotgun metagenomic sequencing

BACKGROUND

Severe community-acquired pneumonia was associated with high morbidity and mortality in children. However, species-level microbiome of lower airway was sparse, and we used shotgun metagenomic next-generation sequencing to explore microbial signatures.

METHODS

We conducted a prospective cohort study to recruit children under 18 who required admission to an intensive care unit for community-acquired pneumonia between December 2019 and February 2022. Lower respiratory specimens were collected on admission for shotgun metagenomic sequencing. The children were divided into two groups. Critical cases were patients with respiratory failure requiring endotracheal ventilator support, and severe cases did not require intubation. Signatures of lower respiratory tract microbiome were compared between groups using an exact k-mer matching metagenomic analysis pipeline (Kraken 2) and a metagenome-assembled genomes pipeline (MetaWRAP).

RESULTS

Totally 66 children were enrolled, and 27 children were critical cases, and the rest were severe cases. There were significant differences in microbial community structure between different severity groups, and microbial abundance was negatively correlated with disease severity. The results showed that Haemophilus influenzae was more prominent in children who were critical, accompanied with increased expression of intracellular transport, secretion, and vesicle transport genes. Rothia mucilaginosa, Dolosigranulum pigrum, and Prevotella melaninogenica tended to be present in less severe community-acquired pneumonia group.

CONCLUSION

This study demonstrated that significantly different microbial community was associated with severity of community-acquired pneumonia requiring intensive care admission. Species-level shotgun metagenomic sequencing facilitates the exploration of potentially pathogenic or protective microbes and shed the light of probiotic development in lower respiratory tract.

C-reactive Protein Variation and Its Usefulness in the Prognostication and Monitoring of Patients With Pneumococcal Pneumonia

Background and objective Community-acquired pneumonia (CAP) is a prevalent and life-threatening infection that causes significant morbidity and mortality. Biomarkers, such as C-reactive protein (CRP), can help to diagnose, monitor, and prognose patients with this condition. This study aimed to analyze the disease course, the CRP peak concentration, its relationship with prognosis, and its variation in hospitalized patients with pneumococcal CAP. Methodology This study included 797 patients diagnosed with pneumococcal CAP and admitted over four years to four different Portuguese hospitals, either to the ICU or the general ward. Results Although CRP peak concentration was not a good predictor of overall hospital mortality, higher peak concentration in older patients (>60 years) was associated with a dismal hospital prognosis. In contrast, younger patients who survived hospital discharge had a non-significant higher peak CRP concentration. A faster time until CRP decreased to at least half of its peak value also correlated with favorable outcomes after adjusting for age and bacteremia [failure to achieve a 50% decrease was associated with an adjusted hazard ratio (HR) for hospital mortality of 6.45; 95% confidence interval (CI): 4.30-9.69]. Conclusions Based on our findings, CRP may be a useful biomarker in the hospital setting for diagnosing and monitoring patients with pneumococcal CAP. Clinicians must be aware of its unique properties, clinical applications, and varying behaviors according to patient age groups.

Treatment Failure and Clinical Stability in Severe Community-Acquired Pneumonia

Treatment failure and clinical stability are important outcomes in community-acquired pneumonia (CAP). It is essential to know the causes and risk factors for treatment failure and delay in reaching clinical stability in CAP. The study of both as well as the associated underlying mechanisms and host response are key to improving outcomes in pneumonia.

Association of admission lactate with mortality in adult patients with severe community-acquired pneumonia

PURPOSE

The present study was conducted to investigate the association of admission lactate with mortality in severe community-acquired pneumonia (SCAP).

METHODS

We performed a retrospective, observational, cohort study on adult SCAP patients admitted to intensive care unit (ICU) in West China Hospital of Sichuan University between December 2011 and December 2018. The primary outcome was hospital mortality. Univariate and then multivariate analysis were performed to identify independent risk factors for hospital mortality. The association of admission lactate categories with hospital mortality was examined in three logistic regression models and Kaplan-Meier plots. We also applied restricted cubic splines to estimate the potential non-linear associations.

RESULTS

In total, 2275 SCAP patients were included. Admission lactate remained a significant factor for mortality after multivariate regression (OR: 1.085; 95% CI: 1.033,1.141; by continuous variable). After lactate was categorized into quartiles and the confounders were fully adjusted, compared with the quartile 1, ORs (95% CIs) of hospital mortality for quartile 2, quartile 3 and quartile 4 were 1.001 (0.759-1.321), 1.153 (0.877-1.516) and 1.593 (1.202-2.109), respectively (P for trend =0.001). Survival curves indicated that elevated lactate was associated with poor prognosis (P < 0.001). Moreover, this association was non-linear, indicating that increased lactate has the most notable impact on mortality within the range of 1.5 to 4 mmol/L (P non-linear: 0.029 for hospital mortality; 0.004 for ICU mortality).

CONCLUSION

Elevated admission lactate has a significant, independent, and potentially non-linear association with increased mortality in SCAP patients.

Application of nested multiplex polymerase chain reaction respiratory and pneumonia panels in children with severe community-acquired pneumonia

Community-acquired pneumonia (CAP) is a serious clinical concern. A lack of accurate diagnosis could hinder pathogen-directed therapeutic strategies. To solve this problem, we evaluated clinical application of nested multiplex polymerase chain reaction (PCR) in children with severe CAP. We prospectively enrolled 60 children with severe CAP requiring intensive care between December 2019 and November 2021 at a tertiary medical center. Nested multiplex PCR respiratory panel (RP) and pneumonia panel (PP) were performed on upper and lower respiratory tract specimens. We integrated standard-of-care tests and quantitative PCR for validation. The combination of RP, PP, and standard-of-care tests could detect at least one pathogen in 98% of cases and the mixed viral-bacterial detection rate was 65%. The positive percent agreement (PPA), and negative percent agreement (NPA) for RP were 94% and 99%; the PPA and NPA for PP were 89% and 98%. The distribution of pathogens was similar in the upper and lower respiratory tracts, and the DNA or RNA copies of pathogens in the lower respiratory tract were equal to or higher than those in the upper respiratory tract. PP detected bacterial pathogens in 40 (67%) cases, and clinicians tended to increase bacterial diagnosis and escalate antimicrobial therapy for them. RP and PP had satisfactory performance to help pediatricians make pathogenic diagnoses and establish therapy earlier. The pathogens in the upper respiratory tract had predictive diagnostic values for lower respiratory tract infections in children with severe CAP.

Monitoring of the Forgotten Immune System during Critical Illness-A Narrative Review

Immune organ failure is frequent in critical illness independent of its cause and has been acknowledged for a long time. Most patients admitted to the ICU, whether featuring infection, trauma, or other tissue injury, have high levels of alarmins expression in tissues or systemically which then activate innate and adaptive responses. Although necessary, this response is frequently maladaptive and leads to organ dysfunction. In addition, the counter-response aiming to restore homeostasis and repair injury can also be detrimental and contribute to persistent chronic illness. Despite intensive research on this topic in the last 40 years, the immune system is not routinely monitored in critical care units. In this narrative review we will first discuss the inflammatory response after acute illness and the players of maladaptive response, focusing on neutrophils, monocytes, and T cells. We will then go through commonly used biomarkers, like C-reactive protein, procalcitonin and pancreatic stone protein (PSP) and what they monitor. Next, we will discuss the strengths and limitations of flow cytometry and related techniques as an essential tool for more in-depth immune monitoring and end with a presentation of the most promising cell associated markers, namely HLA-DR expression on monocytes, neutrophil expression of CD64 and PD-1 expression on T cells. In sum, immune monitoring critically ill patients is a forgotten and missing piece in the monitoring capacity of intensive care units. New technology, including bed-side equipment and in deep cell phenotyping using emerging multiplexing techniques will likely allow the definition of endotypes and a more personalized care in the future.

Value of D-dimer in predicting various clinical outcomes following community-acquired pneumonia: A network meta-analysis

Background

Whether high D-dimer level before treatment has any impact on poor outcomes in patients with community-associated pneumonia (CAP) remains unclear. Therefore, we conducted the first meta-analysis focusing specifically on prognostic value of high D-dimer level before treatment in CAP patients.

Methods

Pubmed, Embase, the Cochrane Central Register of Controlled Trials and World Health Organization clinical trials registry center were searched up to the end of March 2021. Randomized clinical trials (RCT) and observational studies were included to demonstrate the association between the level of D-dimer and clinical outcomes. Data were extracted using an adaptation of the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modeling Studies (CHARMS-PF). When feasible, meta-analysis using random-effects models was performed. Risk of bias and level of evidence were assessed with the Quality in Prognosis Studies tool and an adaptation of Grading of Recommendations Assessment, Development, and Evaluation. Data were analyzed using STATA 14.0 to complete meta and network analysis.

Main outcomes and measures

Besides d-dimer levels in CAP patients with poor outcomes, we also analyzed proportion of patients with or without poor outcomes correctly classified by the d-dimer levels as being at high or low risk. The poor outcome includes severe CAP, death, pulmonary embolism (PE) and invasive mechanical ventilators.

Results

32 studies with a total of 9,593 patients were eventually included. Pooled effect size (ES) suggested that d-dimer level was significantly higher in severe CAP patients than non-severe CAP patients with great heterogeneity (SMD = 1.21 95%CI 0.87–1.56, I² = 86.8% p = 0.000). D-dimer level was significantly elevated in non-survivors compared to survivors with CAP (SMD = 1.22 95%CI 0.67–1.77, I² = 85.1% p = 0.000). Prognostic value of d-dimer for pulmonary embolism (PE) was proved by hierarchical summary receiver operating characteristic curve (HSROC) with good summary sensitivity (0.74, 95%CI, 0.50–0.89) and summary specificity (0.82, 95%CI, 0.41–0.97). Network meta-analysis suggested that there was a significant elevation of d-dimer levels in CAP patients with poor outcome than general CAP patients but d-dimer levels weren’t significantly different among poor outcomes.

Conclusion

The prognostic ability of d-dimer among patients with CAP appeared to be good at correctly identifying high-risk populations of poor outcomes, suggesting potential for clinical utility in patients with CAP.

Prognostic factors in elderly patients admitted to the intensive care unit with community-acquired pneumonia

OBJECTIVE

We aimed to determine the clinical, radiological and laboratory findings that may indicate poor prognosis in severe community acquired pneumonia (CAP) requiring intensified care to reduce the risk of death.

METHODS

The medical histories, demographic characteristics and laboratory values of over 65 years old patients admitted to the intensive care unit (ICU) and diagnosed with CAP were recorded.

RESULTS

Total of 86 patients were included in the study. Among those patients 39 were discharged from the ICU with health but 47 were expired. Diastolic blood pressure was significantly lower in expired patients (p = 0.044). In multivariate analysis, older age (>78 years) (p = 0.004), at admission elevated blood glucose (>108 mg/dL) levels (p = 0.048), decreased serum albumin (<3.5 g/dL) levels (p = 0.043), elevated serum procalcitonin levels (>0.63 μg/L) (p = 0.034) and in blood gas analysis decreased pH (<7.35) (p = 0.042)and increased lactate (>2mmol/L) (p = 0.001) were the significant risk factors for in-ICU mortality.

CONCLUSIONS

At old age, blood glucose and procalcitonin levels increased at the time of admission, serum albumin levels decreased, pH decreased in blood gas analysis and lactate levels increased, and significant mortality determinants in CAP patients over 65 years of age who applied to the intensive care unit.

Procalcitonin as a predictor of early antibiotic treatment failure in patients with gram-negative bloodstream infections caused by urinary tract infections

We retrospectively evaluated whether initial procalcitonin (PCT) levels can predict early antibiotic treatment failure (ATF) in patients with gram-negative bloodstream infections (GN-BSI) caused by urinary tract infections from January 2018 to November 2019. Early ATF was defined as the following: (1) hemodynamically unstable or febrile at Day 3; (2) the need for mechanical ventilation or continuous renal replacement therapy at Day 3; (3) patients who died within 3 days (date of blood culture: Day 0). The study included 189 patients; 42 showed early ATF. Independent risk factors for early ATF were initial admission to the intensive care unit (odds ratio: 7.735, 95% confidence interval: 2.567-23.311; P < 0.001) and PCT levels ≥30 ng/mL (odds ratio: 5.413, 95% confidence interval: 2.188-13.388; P < 0.001). Antibiotic factors were not associated with early ATF. Initial PCT levels may be helpful to predict early ATF in these patients.