Potential Advances of Adjunctive Hyperbaric Oxygen Therapy in Infective Endocarditis

Abstract

Patients with infective endocarditis (IE) form a heterogeneous group by age, co-morbidities and severity ranging from stable patients to patients with life-threatening complications with need for intensive care. A large proportion need surgical intervention. In-hospital mortality is 15-20%. The concept of using hyperbaric oxygen therapy (HBOT) in other severe bacterial infections has been used for many decades supported by various preclinical and clinical studies. However, the availability and capacity of HBOT may be limited for clinical practice and we still lack well-designed studies documenting clinical efficacy. In the present review we highlight the potential beneficial aspects of adjunctive HBOT in patients with IE. Based on the pathogenesis and pathophysiological conditions of IE, we here summarize some of the important mechanisms and effects by HBOT in relation to infection and inflammation in general. In details, we elaborate on the aspects and impact of HBOT in relation to the host response, tissue hypoxia, biofilm, antibiotics and pathogens. Two preclinical (animal) studies have shown beneficial effect of HBOT in IE, but so far, no clinical study has evaluated the feasibility of HBOT in IE. New therapeutic options in IE are much needed and adjunctive HBOT might be a therapeutic option in certain IE patients to decrease morbidity and mortality and improve the long-term outcome of this severe disease.

Contemporary national outcomes of hyperbaric oxygen therapy in necrotizing soft tissue infections

“…In the case of clostridial infections, there is persuasive evidence that hyperbaric oxygen therapy at sufficiently high partial pressures halts the production of alpha-toxin, buying precious time for antibiotics to take effect [ 17 ]. Modern understanding of host-pathogen interaction has advanced the use of HBOT beyond gas gangrene to various complicated chronic and acute infections [ 18 ]. Tissue hypoxia below 30mmHg impedes granulocyte and macrophage function, a situation commonly seen in NSTI as infection progresses [ 19 ].…”

Effect of hyperbaric oxygen on the growth and susceptibility of facultatively anaerobic bacteria and bacteria with oxidative metabolism to selected antibiotics

“…Data using the present guidelines for the antibiotic treatment of IE indicate the need for improved treatment strategies. HBOT is a promising candidate as an adjunctive treatment strategy due to the multifaceted effects and the pathophysiology of IE (Lerche et al 2022 ).…”

Endocarditis in the intensive care unit: an update

“…It has therefore been advocated that further studies should evaluate ticagrelor for prophylactic treatment of IE in patients with prosthetic valves or indwelling devices [75 ▪ ]. Experimental studies also reported improved outcomes in terms of vegetation size, bacterial load and inflammation reduction with the use of dabigatran, a direct thrombin inhibitor [78 ▪ ]. However, such treatments in are challenging in ICU patients, as they were associated with a major risk of bleeding [75 ▪ ].…”

“…Hyperbaric oxygen therapy could also be an adjunctive treatment worth exploring in patients with IE. In experimental models of IE, hyperbaric oxygen therapy has been shown to enhance the bactericidal effect of antibiotics [78 ▪ ].…”