Diagnosis and management of lung infections

Characteristics of lower respiratory tract pathogens in critically ill patients with heatstroke: a retrospective multi-center study

This retrospective multicenter study was conducted across 83 intensive care units (ICUs) in 16 cities in Sichuan, China. Critically ill patients diagnosed with heatstroke and lung infections were included in the study. Specimens from the lower respiratory tract were collected for microbiological testing, and the characteristics of the pathogens were described. A total of 462 patients diagnosed with heatstroke-related pulmonary infections were included, 134 patients (29.0%) tested positive for respiratory pathogens. The most frequently isolated strain was Klebsiella pneumoniae (34.3%), followed by Escherichia coli (28.4%), Staphylococcus aureus (20.9%). The results revealed that in the hyperthermic resistance group, there was a higher proportion of Pseudomonas aeruginosa [14(34.1%) vs 11(11.8%), p=0.002] and Stenotrophomonas maltophilia [4(9.8%) vs 1(1.1%), p=0.030] compared to the hyperthermic control group. And a higher proportion of Staphylococcus aureus [27(29.7%) vs 1(2.3%), p<0.001], were obtained during the earlier stages with elevated temperatures. Patients with Klebsiella pneumoniae (38.3 ± 1.9°C), Staphylococcus aureus (38.5 ± 2.2°C), and Pseudomonas aeruginosa (38.7 ± 1.9°C) exhibited a higher temperature environment. Our study provides crucial insights into the lower respiratory tract pathogenesis of heatstroke patients, identifying key pathogens and their temperature-dependent characteristics, thus providing a foundation for future empirical treatment strategies in heatstroke.

Could the Lung Be a Gateway for Amphotericin B to Attack the Army of Fungi?

Fungal diseases are a significant cause of morbidity and mortality worldwide, primarily affecting immunocompromised patients. Aspergillus, Pneumocystis, and Cryptococcus are opportunistic fungi and may cause severe lung disease. They can develop mechanisms to evade the host immune system and colonize or cause lung disease. Current fungal infection treatments constitute a few classes of antifungal drugs with significant fungi resistance development. Amphotericin B (AmB) has a broad-spectrum antifungal effect with a low incidence of resistance. However, AmB is a highly lipophilic antifungal with low solubility and permeability and is unstable in light, heat, and oxygen. Due to the difficulty of achieving adequate concentrations of AmB in the lung by intravenous administration and seeking to minimize adverse effects, nebulized AmB has been used. The pulmonary pathway has advantages such as its rapid onset of action, low metabolic activity at the site of action, ability to avoid first-pass hepatic metabolism, lower risk of adverse effects, and thin thickness of the alveolar epithelium. This paper presented different strategies for pulmonary AmB delivery, detailing the potential of nanoformulation and hoping to foster research in the field. Our finds indicate that despite an optimistic scenario for the pulmonary formulation of AmB based on the encouraging results discussed here, there is still no product registration on the FDA nor any clinical trial undergoing ClinicalTrial.gov.

Biofilms: Formation, Research Models, Potential Targets, and Methods for Prevention and Treatment

Due to the continuous rise in biofilm-related infections, biofilms seriously threaten human health. The formation of biofilms makes conventional antibiotics ineffective and dampens immune clearance. Therefore, it is important to understand the mechanisms of biofilm formation and develop novel strategies to treat biofilms more effectively. This review article begins with an introduction to biofilm formation in various clinical scenarios and their corresponding therapy. Established biofilm models used in research are then summarized. The potential targets which may assist in the development of new strategies for combating biofilms are further discussed. The novel technologies developed recently for the prevention and treatment of biofilms including antimicrobial surface coatings, physical removal of biofilms, development of new antimicrobial molecules, and delivery of antimicrobial agents are subsequently presented. Finally, directions for future studies are pointed out.

Performance of a new single-use bronchoscope versus a marketed single-use comparator: a bench study

BACKGROUND

Single-use flexible bronchoscopes eliminate cross contamination from reusable bronchoscopes and are cost-effective in a number of clinical settings. The present bench study aimed to compare the performance of a new single-use bronchoscope (Boston Scientific EXALT Model B) to a marketed single-use comparator (Ambu aScope 4), each in slim, regular and large diameters.

METHODS

Three bronchoscopy tasks were performed: water suction and visualization, "mucus" mass (synthetic mucoid mixture) suctioned in 30 s, and "mucus" plug (thicker mucoid mixture) suction. Suction ability, task completion times, and subjective ratings of visualization and overall performance on a scale of one to 10 (best) were compared. All bronchoscopy tasks were completed by 15 physicians representing diversity in specialization including pulmonary, interventional pulmonary, critical care, anesthesia, and thoracic surgery. Each physician utilized the six bronchoscope versions with block randomization by bronchoscope and task.

RESULTS

Aspirated mean mass of "mucus" using EXALT Model B Regular was comparable to that for an aScope 4 Large (41.8 ± 8.3 g vs. 41.5 ± 5.7 g respectively, p = 0.914). In comparisons of scopes with the same outer diameter, the aspirated mean mass by weight of water and "mucus" was significantly greater for EXALT Model B than for aScope 4 (p < 0.001 for all three diameters). Mean ratings for visualization attributes were significantly better for EXALT Model B compared to aScope 4 (p-value range 0.001-0.029).

CONCLUSION

A new single-use bronchoscope provided strong suction capability and visualization compared to same-diameter marketed single-use comparators in a bench model simulation.

Surgical management of non-mycobacterial fungal infections

Fungal infections of the lung are common in endemic areas and in immunocompromised patients. Antifungal therapy is the cornerstone of medical therapy for most pulmonary fungi but surgery is an important adjunct in cases of complicated disease or resistant organisms. A multidisciplinary approach including pulmonary medicine, infectious disease, interventional radiology, and thoracic surgery is favored. This article reviews the surgical management of common fungal pulmonary infections and their sequelae.

Low dose of glucocorticoid decreases the incidence of complications in severely burned patients by attenuating systemic inflammation

BACKGROUND

Excessive systemic inflammatory response remains as a major problem underlying severe burns. This study aimed to assess the effect of low-dose glucocorticoid treatment in downregulating systemic inflammation in severely burned patients.

METHODS

A prospective study from 2001 to 2014 at our hospital was conducted to compare the patients who received low-dose glucocorticoid during the acute phase with those who did not. Patients with burns 70% or greater of their total body surface area were included, and their plasma levels of inflammatory cytokines and clinical outcomes were compared.

RESULTS

A total of 69 patients were included in this study, with 31 patients receiving glucocorticoid treatment and the others not. Patient demographics including age, burn size, and incidence of inhalation injury were similar in both groups. The incidence of pulmonary infection and stress ulcer (and/or hemorrhage) was 24.2% and 3.0% in the treatment group, respectively, significantly lower than 47.8% and 19.6% of the control group (P < .05). Length of hospital stay was almost 13 days shorter in the treatment group (P < .05), whereas there was no significant difference in the overall mortality, duration of mechanical ventilation, and incidence of sepsis between the 2 groups. The enzyme-linked immunosorbent assay results confirmed that the plasma levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, and interleukin-8 were significantly lower in the treatment group (P < .05).

CONCLUSION

Low dose of glucocorticoid treatment during the acute phase could reduce the levels of proinflammatory cytokines in severely burned patients and subsequently decrease the incidence of pulmonary infection and stress ulcer, as well as the length of hospital stay.