Chlorhexidine use in adult patients on ICU

Catheter-Based Medical Device Biofilm Ablation Using Histotripsy: A Parameter Study

OBJECTIVE

Biofilm formation in medical catheters is a major source of hospital-acquired infections which can produce increased morbidity and mortality for patients. Histotripsy is a non-invasive, non-thermal focused ultrasound therapy and recently has been found to be effective at removal of biofilm from medical catheters. Previously established histotripsy methods for biofilm removal, however, would require several hours of use to effectively treat a full-length medical catheter. Here, we investigate the potential to increase the speed and efficiency with which biofilms can be ablated from catheters using histotripsy.

METHODS

Pseudomonas aeruginosa (PA14) biofilms were cultured in in vitro Tygon catheter mimics and treated with histotripsy using a 1 MHz histotripsy transducer and a variety of histotripsy pulsing rates and scanning methods. The improved parameters identified in these studies were then used to explore the bactericidal effect of histotripsy on planktonic PA14 suspended in a catheter mimic.

RESULTS

Histotripsy can be used to remove biofilm and kill bacteria at substantially increased speeds compared with previously established methods. Near-complete biofilm removal was achieved at treatment speeds up to 1 cm/s, while a 4.241 log reduction in planktonic bacteria was achieved with 2.4 cm/min treatment.

CONCLUSION

These results represent a 500-fold increase in biofilm removal speeds and a 6.2-fold increase in bacterial killing speeds compared with previously published methods. These findings indicate that histotripsy shows promise for the treatment of catheter-associated biofilms and planktonic bacteria in a clinically relevant time frame.

Should oral chlorhexidine remain in ventilator-associated pneumonia prevention bundles?

Ventilator-associated pneumonia (VAP) is related with high mortality, duration of mechanical ventilation and costs. Recent studies have questioned the safety and effectiveness of oral chlorhexidine to prevent VAP. We sought to verify whether the adverse effects of this substance outweigh its benefits. We searched several databases and selected studies that investigated the use of oral chlorhexidine and its impact on mortality. No association between oral chlorhexidine and lower VAP rates was found on meta-analyses of double-blind randomized trials, however significant increase in mortality was reported. It is speculated that chlorhexidine can cause damage to several organic sectors and cytotoxicity. Although it still can be beneficial in specific settings, robust evidence to recommend its routine application for all mechanically ventilated patients is lacking; therefore, given the possibility of harm, it would be better to follow the principle of non-maleficence until more studies becomes available.

What is new in catheter use and catheter infection prevention in the ICU

PURPOSE OF REVIEW

Short-term intravascular catheters are instrumental in the care of critically ill patients. Despite their benefits, they also are potential entries for systemic infections. There is a growing body of literature on catheter use and the prevention of intravascular catheter infections in intensive care. This review highlights major recent contributions to the topic and put them into perspective to recommendations on best practice procedures.

RECENT FINDINGS

Many studies published in the last years have evaluated prevention strategies applying technology and addressing behavior change. Skin disinfection with 2% alcoholic chlorhexidine-gluconate (CHG) and CHG-impregnated dressings are increasingly used in clinical practice. However, the role of universal CHG bathing remains controversial. A number of new and innovative technologies are in development. Recent qualitative research offers new perspectives about behavior change interventions to improve implementation.

SUMMARY

Many options for effective intravascular catheter infection prevention are currently available. A number of recent systematic reviews and meta-analyses not only confirmed measures targeting best practice and technology at catheter insertion and catheter care but also challenged interventions, such as CHG bathing. More focus should be put to implementation strategies.

Should oral chlorhexidine remain in ventilator-associated pneumonia prevention bundles?

Ventilator-associated pneumonia (VAP) is related with high mortality, duration of mechanical ventilation and costs. Recent studies have questioned the safety and effectiveness of oral chlorhexidine to prevent VAP. We sought to verify whether the adverse effects of this substance outweigh its benefits. We searched several databases and selected studies that investigated the use of oral chlorhexidine and its impact on mortality. No association between oral chlorhexidine and lower VAP rates was found on meta-analyses of double-blind randomized trials, however significant increase in mortality was reported. It is speculated that chlorhexidine can cause damage to several organic sectors and cytotoxicity. Although it still can be beneficial in specific settings, robust evidence to recommend its routine application for all mechanically ventilated patients is lacking; therefore, given the possibility of harm, it would be better to follow the principle of non-maleficence until more studies becomes available.

Antiseptic mouthwash, the nitrate-nitrite-nitric oxide pathway, and hospital mortality: a hypothesis generating review

Meta-analyses and several large cohort studies have demonstrated that antiseptic mouthwashes are associated with mortality in hospitalized patients. A clear pathogenic mechanism is lacking, leading to controversy and a reluctance to abandon or limit the use of antiseptic mouthwashes. Here, we generate the hypothesis that a disturbance in nitric oxide homeostasis by antiseptic mouthwashes may be responsible for the observed increase in mortality risk. Nitric oxide is essential in multiple physiological processes, and a reduction in nitric oxide bioavailability is associated with the occurrence or worsening of pathologies, such as atherosclerosis, diabetes, and sepsis. Oral facultative anaerobic bacteria are essential for the enterosalivary nitrate–nitrite–nitric oxide pathway due to their capacity to reduce nitrate to nitrite. Nitrate originates from dietary sources or from the active uptake by salivary glands of circulating nitrate, which is then excreted in the saliva. Because antiseptic mouthwashes eradicate the oral bacterial flora, this nitric oxide-generating pathway is abolished, which may result in nitric oxide-deficient conditions potentially leading to life-threatening complications such as ischaemic heart events or sepsis.

The dilemma of COVID-19 in dental practice concerning the role of saliva in transmission: a brief review of current evidence

From December 12, 2019, a pandemic of acute respiratory syndrome, the novel human coronavirus disease (COVID-19), caused by a novel β-coronavirus (2019- nCoV) began to grow globally by person-to-person transmission. The production of airborne material during aerosol generating dental procedures would expose dental team and patients to remarkable risk of transmission concerning the faceto- face communication and splattered saliva, blood, and other body fluids. Dental professionals can be a substantial help in preventing the transmission of COVID-19. This study has reviewed relevant current evidences in literature that has addressed the role of saliva and the threats that may be inherent in transmission of the disease during dental procedures. The study also offers feasible proactive and preventive measures for dental practice during the outbreak to block possible person-toperson or indirect transmission in dental settings.

A state of the art review on optimal practices to prevent, recognize, and manage complications associated with intravascular devices in the critically ill

Intravascular catheters are inserted into almost all critically ill patients. This review provides up-to-date insight into available knowledge on epidemiology and diagnosis of complications of central vein and arterial catheters in ICU. It discusses the optimal therapy of catheter-related infections and thrombosis. Prevention of complications is a multidisciplinary task that combines both improvement of the process of care and introduction of new technologies. We emphasize the main component of the prevention strategies that should be used in critical care and propose areas of future investigation in this field.